NC State
  • Editorialpp 6305-6309Hubbe, M. A. (2015)."Oops, I thought that those books had been deacidified," BioRes. 10(4), 6305-6309.AbstractPDF
    Major libraries have been placing increasing reliance upon non-aqueous mass deacidification in an effort to avoid hydrolytic decomposition of the cellulose during storage of bound volumes. Such decomposition is especially a problem when the printing papers used in manufacture of the books have been prepared under acidic conditions, using aluminum sulfate. But there is reason to doubt that the widely used non-aqueous treatments, in which “alkaline reserve” particles are deposited in the void spaces of the paper, can achieve neutralization of acidity throughout the paper structure under the conditions most commonly used for treatment and storage. Anecdotal evidence suggests that alkaline particles such as CaCO3, MgO, Mg(OH)2, or ZnO can be present for long periods of time adjacent to acidic parts of cellulosic fibers without neutralization of the acidity, especially the acidity within the fibers. If these phenomena can be better understood, then there may be an opportunity to use a high-humidity treatment of certain “deacidified” books in order to achieve more pervasive protection against acid-induced degradation.
  • Editorialpp 6310-6313Gamelas, J. A. F., and Ferraz, E. (2015). "Composite films based on nanocellulose and nanoclay minerals as high strength materials with gas barrier capabilities: Key points and challenges," BioRes. 10(4), 6310-6313.AbstractPDF
    Composites of nanocellulose with layered silicates have recently emerged as a new type of composite materials offering superior strength, as well as thermal and gas barrier properties. These organic-inorganic hybrid composites with a nacre-like structure can be obtained from renewable resources and are environmentally friendly. They can potentially be presented as a serious alternative in the near future to several polymers or other polymer-inorganic composites, for applications in food packaging or electronic devices. The discussion here will be directed to: what are the new opportunities and challenges that arise for these materials aiming at their competition with well-established materials in the market.
  • Editorialpp 6314-6317Hao, X., Liu, C., Cao, H., Liu, Y., Peng, H., and Shen, J. (2015). "Use of byproduct from cellulosic ethanol production as an additive for concrete: A possible win-win strategy?" BioRes. 10(4), 6314-6317.AbstractPDF
    Technologists are facing increasing demands to achieve ecologically sustainable industrial practices. Currently the concrete industry is a significant contributor to greenhouse gas emissions. On the other hand, the scaling up of cellulosic ethanol technology has not been a very easy task. In this context, the integration of “greener” concrete with cellulosic ethanol technology may open up promising possibilities. The solid byproducts from cellulosic ethanol production process have been demonstrated to increase the strength of concrete structures when used as a partial cement replacement. Such a delicate integration can also lead to reduction in both carbon footprint and product cost. The possible commercialization of the integrated technologies would provide win-win benefits for both industries.
  • Editorialpp 6318-6320Ali, O. F., and Koukoulas, A. A. (2015). "Approaches to energy pellet cost and quality optimization" BioRes. 10(4), 6318-6320.AbstractPDF
    As the global demand for biomass-derived energy pellets continues to expand, industry focus is expected to quickly migrate from project development to ways of lowering operating costs. Process optimization and the utilization of low-cost feedstocks are expected to be of special interest. This new focus will present opportunities for targeted research that can utilize low-value wood and biomass feedstocks, increase yields, and improve product quality.
  • Researchpp 6321-6331Feng, J., Xu, K., Shi, Q., Huang, X., and Li, K. (2015). "Algal decay resistance of conventional and novel wood-based composites," BioRes. 10(4), 6321-6331.AbstractPDF
    Measures of the resistance to algal decay of conventional (medium density fiberboard [MDF] and plywood) and novel wood-based composites (WPC) were investigated in the same or varying wood species by using an artificial accelerated test with four mixed algal suspensions (Chlorella vulgaris, Ulothrix sp., Scenedesmus quadricauda, and Oscillatoria sp.). The morphology characterization of the surface and fracture of the specimens was analyzed using scanning electron microscopy (SEM) and a digital instrument. The pH value and the mass loss rate of the different wood species were also tested. The results showed that the algal resistance of the MDF and plywood were superior to that of the WPC of the same wood species. Furthermore, the algal resistance capacity of WPC made from various wood species were ranked as: Liquidambar formosana > Cunninghamia lanceolata and Melaleuca leucadendra > Ricinus communis > Eucalyptus grandis × E. urophylla and Pinus massoniana. There was a close relationship between the pH value and the algal resistance level; as the pH value increased, the alga resistance of the WPC also increased. The algal colonization only had a negative effect on the appearance of the samples.
  • Researchpp 6332-6347Jiang, Y., Nie, S., Liang, D., Zhang, N., Wang, S., and Song, X. (2015). "Effects of alkaline hydrogen peroxide pre-extraction on bamboo lignin chemistry and other bamboo chemical components," BioRes. 10(4), 6332-6347.AbstractPDF
    This paper aimed to investigate the reasons for improved properties of bamboo alkaline peroxide mechanical pulp (APMP), such as relatively high brightness and low post-colour number, by alkali hydrogen peroxide pre-extraction (AHPP) treatment. It was found that AHPP could affect the dissolution of 1% sodium hydroxide extractives, benzene-ethanol extractives, and acid-soluble lignin. The results of Fourier transform infrared (FTIR) and 13C-nuclear magnetic resonance spectroscopy (13C-NMR) illustrated that carboxyl, syringyl, guaiacyl, acetyl, and methoxyl groups of the milled wood lignin (MWL) in bamboo were degraded slightly after AHPP treatment. However, some lignin-like structures, the links of α-O-4, β-O-4, and some carbohydrates such as xylan, α-glucose, β-glucose, α-mannose, and β-mannose in lignin-carbohydrate complexes (LCCs) were degraded noticeably. The analysis of UV spectrophotometry indicated that AHPP treatment was conductive to the degradation of some chromophores in MWL. The degradation of MWL and LCC under simulated AHPP conditions showed consistency with the above results.
  • Researchpp 6348-6362Hou, J., Fu, F., Lu, K., and Chen, L. (2015). "Highly conductive fiberboards made with carbon and wood fibers," BioRes. 10(4), 6348-6362.AbstractPDF
    Carbon fibers (CFs) were mixed with wood fibers using the solution blend method to make highly conductive fiberboards. The microstructure, conductivity, shielding effectiveness (SE), and mechanical properties of fiberboards filled with CFs of various lengths and contents were investigated. The uniform distribution of CFs formed an excellent, three-dimensional conductive network. The CF-filled fiberboards exhibited evidence of percolation and piezoresistivity. A greater content of shorter CFs was necessary to realize the effects of percolation. The corresponding thresholds of fiberboards containing CFs of 2, 5, and 10 mm in length were 1.5%, 0.75%, and 0.5%, respectively. The volume resistance of fiberboards tended to be stable as the external pressure increased to 1.4 MPa. The volume resistivity of fiberboards reached equilibrium when the CF content was 10%. The fiberboards with greater than 10% CF content exhibited a SE of 30 dB above the average, yet they met the requirements for commercial application. The mechanical properties of fiberboards were investigated, and CFs were found to enhance the modulus of rupture (MOR) and modulus of elasticity (MOE). Therefore, it was concluded that fiberboards containing CF of 5 mm in length exhibited the best performance between percolation threshold and steady CF content.
  • Researchpp 6363-6377Fatima, R., Ahmed, S., Arshad, M., and Sahi, S. T. (2015). "Effect of seasoning of different woods on resistance against Odontotermes obesus (Ramb.) under laboratory and field choice and no-choice tests," BioRes. 10(4), 6363-6377.AbstractPDF
    The effects of seasoning on resistance of sapwood and heartwood of Dalbergia sissoo Roxb., Acacia nilotica Wild., and Pinus wallichiana A. B. Jacks against consumption by Odontotermes obesus (Ramb.) was evaluated in no-choice and choice laboratory and field experiments. Seasoning was done in an oven at 60, 80, and 100 °C for 10 and 15 days. The amount of wood consumed generally decreased as the drying temperature increased, indicating that the drying process contributed to termites’ resistance of the woods and made them unpalatable for the termites. The woods that were dried at 100 °C for 15 days showed a significant reduction in weight after the consumption by termites compared to the woods dried at 60 and 80 °C and control both in laboratory and field trials. Similarly, the wood that was dried at 100 °C for 15 days showed highest termite mortality rate in laboratory no choice and choice tests. Consequently, the termites showed maximum feeding propensity on unseasoned P. wallichiana and the minimum on seasoned D. sissoo measured with significant differences in weight loss and mortality. Based on the feeding indicated by wood weight loss, the descending order of preference was Dalbergia sissoo > Acacia nilotica > Pinus wallichiana. The importance of wood seasoning for termites’ resistance is also discussed.
  • Researchpp 6378-6387Nordin, N. A., Sulaiman, O., Hashim, R., Salim, N., Nasir, M., Sato, M., and Hiziroglu, S. (2015). "Effect of adhesive spreading rate on the performance of laminated compressed oil palm trunks," BioRes. 10(4), 6378-6387.AbstractPDF
    The large availability and cheap price of oil palm (Elaeis guineensis) trunk makes it an attractive raw material for value-added applications, but its low density and high carbohydrate content are highly undesirable. In this work, oil palm trunk (OPT) was steam-pretreated and compressed at high temperature. The compressed OPT was laminated using polyvinyl acetate (PVAc) using either 250 or 500 g/m2 adhesive spread rate (ASR). Soil burial testing was performed for three months on two different samples to study the deterioration and weight loss by bio-organisms. The laminated, compressed OPT formed with high PVAc ASR was found to be more durable against bio-organisms. The thermal stability of the compressed OPT was studied by thermogravimetric analysis (TGA), and it was observed that the weight loss was lower for steam-pretreated samples compared to those without steam pretreatment. Moisture absorption-desorption testing of compressed OPT was performed, and a hysteresis curve was generated. It was found that laminated, compressed OPTs with 500 g/m2 ASR had lower moisture absorption than those with 250 g/m2 ASR.
  • Researchpp 6388-6394Mirski, R., and Dziurka, D. (2015). "Low-density oriented strand boards," BioRes. 10(4), 6388-6394.AbstractPDF
    This study evaluated the possibility of producing low-density oriented strand boards (OSB) from industrial chips of Pinus sylvestris L. Statistical analysis was used to determine the lowest possible density of resulting OSBs meeting the requirements of EN standard 300 for type 3 boards. The analysis revealed that this type of board could be obtained with a density as low as 425 kg/m3, corresponding to a compression ratio of about 0.85 for pine wood. An important parameter was the quality of the pine chips, the dimensions of which should be as close as possible to the dimensions of standard wood strands.
  • Researchpp 6395-6416McGavin, R. L., Bailleres, H., Fehrmann, J., and Ozarska, B. (2015). "Stiffness and density analysis of rotary veneer recovered from six species of Australian plantation hardwoods," BioRes. 10(4), 6395-6416.AbstractPDF
    Commercial interest in Australian hardwood plantations is increasing. The timber industry is investigating alternative supplies of forest resources, and the plantation growing industry is eager to explore alternative markets to maximize financial returns. Identifying suitable processing strategies and high-value products that suit young, plantation-grown hardwoods have proven challenging; however, recent veneer processing trials using simple veneer technology have demonstrated more acceptable recoveries of marketable products. The recovered veneers have visual qualities that are suitable for structurally-based products; however, the mechanical properties of the veneer are largely unknown. Veneers resulting from processing trials of six commercially important Australian hardwood species were used to determine key wood properties (i.e., density, dynamic modulus of elasticity (MoE), and specific MoE). The study revealed that a wide variation of properties existed between species and also within species. Simple mathematical modeling, using sigmoidal curves, was demonstrated to be an effective method to model the evolution of key wood properties across the billet radius and along the resulting veneer ribbon with benefits for tree breeders and processors.
  • Researchpp 6417-6427Liu, H., Gao, J., and Chen, Y. (2015). "Effects of pre-freezing prior to drying upon some physical and mechanical properties of Eucalyptus urophylla x Eucalyptus grandis wood," BioRes. 10(4), 6417-6427.AbstractPDF
    To investigate the effect of pre-freezing treatment on the shrinkage properties and discoloration of Eucalyptus urophylla × Eucalyptus grandis wood, E. urophylla × E. grandis wood samples were treated by pre-freezing at -20 and -40 °C for 72 h and then dried to reach equilibrium moisture content at 12% and 8%, respectively. Color changes were measured by colorimeter and evaluated by diffuse reflectance visible (DRV) spectrometry; mechanical properties were also tested. The results showed that the shrinkage of Eucalyptus wood samples decreased after being pre-frozen, and the overall color change ΔE* increased by 6.11 when the treatment temperature changed from minus 20 to -40 °C. Absorption (ΔK/S) spectra in the range of 450 to 740 nm of the treatment samples exhibited flat-lined, which suggests that the color of wood stabilizes after being pre-frozen and dried. The tensile, compression and bending strengths decreased 4.74, 6.05, 1.18 after pre-freezing treatment at -40 °C, respectively. Pre-freezing treatment at -20 °C is better than that at -40 °C for improving the drying properties of E. urophylla × E. grandis wood.
  • Researchpp 6428-6441Bumbudsanpharoke, N., and Ko, S. (2015). "In-situ green synthesis of gold nanoparticles using unbleached kraft pulp," BioRes. 10(4), 6428-6441.AbstractPDF
    Facile green synthesis of gold nanoparticles (AuNPs) on cellulose fiber was successfully achieved by reducing chloroauric acid (HAuCl4·3H2O) by means of unbleached kraft pulp. A significant color change in pulp fiber indicating the in-situ formation of gold was observed with one-step synthesis in an autoclave. As-prepared AuNP-cellulose fiber nanocomposites were thoroughly characterized by UV–Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Gold nanoparticles were uniformly dispersed on the surface of the fiber by the bio-reduction of Au3+ from metal salt to Au0 with the α-carbonyl group and conjugated carbonyl of phenolic groups of lignin. The AuNPs formed on cellulose fibers were estimated to have average sizes of approximately 12.5, 12.4, 16.4, and 21.0 nm, depending on the concentration of Au3+ involved in the synthesis.
  • Researchpp 6442-6456Ferrer, A., Vargas, F., Jameel, H., and Rojas, O. J. (2015). "Influence of operating variables and model to minimize the use of anthraquinone in the soda-anthraquinone pulping of barley straw," BioRes. 10(4), 6442-6456.AbstractPDF
    Soda-anthraquinone (soda-AQ) pulping of barley straw was used to obtain cellulosic pulps for papermaking purposes. The identified parameters, or variables to be optimized, were operating time, anthraquinone concentration, and PFI refiner revolutions, and the influence of these operating variables on pulp properties was studied. A polynomial model that reproduced the experimental results with errors less than 6% was developed. Operating variables were found (46 min of processing time, 0.4 wt.% of anthraquinone concentration, and 3000 rpm of PFI revolution) that yielded competitive pulp properties (82 °SR beating grade number, 870 mL/g of viscosity, Kappa number of 13, 77 Nm/g of tensile index, and 30% ISO brightness) at reasonable chemical and energy costs. On the other hand, this study highlights the usefulness of this polynomial model as a method to minimize the use of anthraquinone in these pulping processes and to be able to predict what the pulp properties will be. For comparison purposes, new operating conditions were found, and the pulp properties still remain at a very good level for this cereal straw.
  • Researchpp 6457-6478Mohammed, I. Y., Abakr, Y. A., Kazi, F. K., Yusuf, S., Alshareef, I., and Chin, S. A. (2015). "Pyrolysis of Napier grass in a fixed bed reactor: Effect of operating conditions on product yields and characteristics," BioRes. 10(4), 6457-6478.AbstractPDF
    This study presents a report on pyrolysis of Napier grass stem in a fixed bed reactor. The effects of nitrogen flow (20 to 60 mL/min), and reaction temperature (450 to 650 °C) were investigated. Increasing the nitrogen flow from 20 to 30 mL/min increased the bio-oil yield and decreased both bio-char and non-condensable gas. 30 mL/min nitrogen flow resulted in optimum bio-oil yield and was used in the subsequent experiments. Reaction temperatures between 450 and 600 °C increased the bio-oil yield, with maximum yield of 32.26 wt% at 600 oC and a decrease in the corresponding bio-char and non-condensable gas. At 650 °C, reductions in the bio-oil and bio-char yields were recorded while the non-condensable gas increased. Water content of the bio-oil decreased with increasing reaction temperature, while density and viscosity increased. The observed pH and higher heating values were between 2.43 to 2.97, and 25.25 to 28.88 MJ/kg, respectively. GC-MS analysis revealed that the oil was made up of highly oxygenated compounds and requires upgrading. The bio-char and non-condensable gas were characterized, and the effect of reaction temperature on the properties was evaluated. Napier grass represents a good source of renewable energy when all pyrolysis products are efficiently utilized.
  • Researchpp 6479-6495Liu, Y., Chen, Y., Zhao, Y., Tong, Z., and Chen, S. (2015). "Superabsorbent sponge and membrane prepared by polyelectrolyte complexation of carboxymethyl cellulose/hydroxyethyl cellulose-Al3+," BioRes. 10(4), 6479-6495.AbstractPDF
    A novel carboxymethyl cellulose/ hydroxyethyl cellulose-Al3+ (CMC/HEC-Al3+) hydrogel was prepared through electrostatic complexing between the anionic polyelectrolyte CMC and cationic cross-linking agent Al3+. The structure and properties of the hydrogel were characterized using FTIR, TGA, and SEM. The viscoelasticities of the swollen hydrogel were measured using the rheology test. The results indicated that a porous network structure was formed in the hydrogel. The content of CMC, HEC, and Al3+ can significantly affect its structure and characteristics. A sponge and membrane were prepared from the CMC/HEC-Al3+ hydrogel by freeze-drying and oven drying, respectively. Their swelling behaviors were investigated in water and saline solutions, and quantified with a swelling kinetic simulation. The results indicated that electrostatic effects, physical entanglement, and intra- and intermolecular hydrogen bonds contributed to the cross-linking network structure, with the electrostatic effect acting as the dominant force. In all, both superabsorbent sponge and membrane prepared from CMC/HEC-Al3+ hydrogel showed excellent swelling behavior and could be used in dressing wounds.
  • Researchpp 6496-6511Şahin Kol, H., and Yalçın, I. (2015). "Predicting wood strength using dielectric parameters," BioRes. 10(4), 6496-6511.AbstractPDF
    There are various methods for nondestructive imaging of the internal structure of wood. A microwave nondestructive method based on the dielectric properties of a medium is an area of great interest for predicting wood strength in the worldwide wood industry, but the reliable prediction of strength in wood still has not been solved in a satisfying manner. Hence, answering the question of how dielectric properties of the wood are related to strength may improve the efficiency of models for predicting structural performance of wood by microwaves. Relationships were evaluated in this work between dielectric parameters (dielectric constant, loss factor, and loss tangent) and the strength properties of wood. Samples were prepared from fir and oak wood. Dielectric measurement was performed at a frequency of 9.8 GHz using Von Hippel’s Transmission Line Method. Wood density and some mechanical properties were then determined according to related ISO standards. The results showed that there were good relationships between the dielectric parameters and the MOR, MOE, IBS, and CS, especially for oak wood. The dielectric parameters were promising to predict wood strength with a high accuracy for oak but not fir, and the dielectric constant had a higher precision degree than the loss tangent and loss factor.
  • Researchpp 6512-6521Kvietková, M., Gaff, M., Gašparík, M., Kaplan, L., and Barcík, S. (2015). "Surface quality of milled birch wood after thermal treatment at various temperatures," BioRes. 10(4), 6512-6521.AbstractPDF
    The surface quality of thermally modified birch wood was examined after plane milling. The surface quality was assessed based on the arithmetic mean deviation of the assessed profile Ra. Plane milling was carried out at various cutting speeds of 20, 40, and 60 m/s and feed speeds 4, 8, and 11 m/min. Based on the results, it was concluded that thermal treatment reduced the surface roughness of milled birch wood, but the decrease was not statistically significant. The cutting speed and feed had the greatest impact on all monitored factors. Increases in cutting speed reduced the average roughness, while increases in feed speed had the opposite effect. The highest roughness was achieved after plane milling with a feed speed of 11 m/min.
  • Researchpp 6522-6537Bensah, E. C., Kádár, Z., and Mensah, M. Y. (2015). "Ethanol production from hydrothermally-treated biomass from West Africa," BioRes. 10(4), 6522-6537.AbstractPDF
    Despite the abundance of diverse biomass resources in Africa, they have received little research and development focus. This study presents compositional analysis, sugar, and ethanol yields of hydrothermal pretreated (195 °C, 10 min) biomass from West Africa, including bamboo wood, rubber wood, elephant grass, Siam weed, and coconut husk, benchmarked against those of wheat straw. The elephant grass exhibited the highest glucose and ethanol yields at 57.8% and 65.1% of the theoretical maximums, respectively. The results show that the glucose yield of pretreated elephant grass was 3.5 times that of the untreated material, while the ethanol yield was nearly 2 times higher. Moreover, the sugar released by the elephant grass (30.8 g/100 g TS) was only slightly lower than by the wheat straw (33.1 g/100 g TS), while the ethanol yield (16.1 g/100 g TS) was higher than that of the straw (15.26 g/100 g TS). All other local biomass types studied exhibited sugar and ethanol yields below 33% and 35% of the theoretical maximum, respectively. Thus, elephant grass is a highly promising biomass source for ethanol production in Africa.
  • Researchpp 6538-6547Santos, R. B., Gomide, J. L., and Hart, P. W. (2015). "Kraft pulping of reduced metal content eucalyptus wood: Process impacts," BioRes. 10(4), 6538-6547.AbstractPDF
    The effect of using acid pretreated eucalyptus wood chips in the Lo-Solids® pulping process was evaluated in the laboratory. Lo-Solids® cooking technology was chosen to evaluate the impact of acid pretreatments on the cooking performance, brown stock chemical composition, and black liquor heating value. The acid leaching stage reduced the contents of transition metals and other non-process elements in the wood chips and in the pulps produced. Benefits were detected in terms of the reduction in white liquor charge, increase in pulp yield, as well as pulp viscosity and black liquor heating value. Carbohydrate content and other wood/pulp constituents were not affected by the acid leaching pretreatments.
  • Researchpp 6548-6564Gao, X., Peng, L., Li, H., and Chen, K. (2015). "Formation of humin and alkyl levulinate in the acid-catalyzed conversion of biomass-derived furfuryl alcohol," BioRes. 10(4), 6548-6564.AbstractPDF
    To avoid undesired polymerization and maximize the selectivity of alkyl levulinate from the acid-catalyzed conversion of biomass-derived furfuryl alcohol, the effects of catalyst and reaction parameters on the formations of humin and alkyl levulinate were investigated. The results show that Amberlyst 15, of moderate acidic strength, was more favorable for the selective conversion of furfuryl alcohol to alkyl levulinate, and heteropolyacids of strong acidic strength tended to promote furfuryl alcohol polymerization. Compared with water as a reaction medium, alcohol significantly lowered humin formation and enhanced the yield of the resulting products. The formations of humin and alkyl levulinate were both favored at high catalyst loadings and reaction temperatures. An augmentation in initial furfuryl alcohol concentration caused an increase in humin formation and a decrease in alkyl levulinate yield. A high alkyl levulinate yield of up to 94% (100% furfuryl alcohol conversion) was achieved at 110 °C for 4 h with 5 g/L Amberlyst 15 catalyst and an initial furfuryl alcohol concentration of 0.1 mol/L. At this point, about 5% furfuryl alcohol was polymerized to form the humin, and its polymerization occurred mainly during the initial reaction stage.
  • Researchpp 6565-6575Zhang, Z., Chen, J., Pang, Z., Lucia, L. A., Li, F., and Yang, G. (2015). "Ionic liquids as a new platform for fiber brittleness removal," BioRes. 10(4), 6565-6575.AbstractPDF
    In the present study, three ionic liquids, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-allyl-3-methylimidazolium ([AMIM]Cl), and 1-ethyl-3-methylimidazolium chloride dimethyphosphate ([EMIM]DMP), were used to eliminate the brittleness of recycled fibers. The results showed that the pretreatments with ionic liquids were able to modify and improve the properties of recycled fibers even at high moisture contents. [EMIM]DMP gave better performance compared to [BMIM]Cl and [AMIM]Cl, which can tolerate higher moisture contents. The optimal conditions of EMIM]DMP pretreatment were moisture content of 65%, [EMIM]DMP dosage of 20 wt-%, 80 °C, and 60 min, for which a higher brittleness removal was obtained. The tensile index, bursting index, and tearing index of handsheets were increased by 32.4%, 57.0%, and 46.5%, respectively. Fiber quality was improved as demonstrated by fiber length, lowered fines content, and increased swellability. Such results imply that ionic liquids pretreatment can promote the swelling of recycled fibers and remove their brittleness.
  • Researchpp 6576-6585Chen, Z., Yu, G., Yuan, X., Wang, Q., and Kan, J. (2015). "Improving the conventional pelletization process to save energy during biomass densification," BioRes. 10(4), 6576-6585.AbstractPDF
    A pellet mill is currently the most frequently used method for producing pellets using either a ring die or a flat die. In the densification process, a great amount of energy is required to avoid spring-back and to overcome the friction between the material and the channel surface of the die. However, extra energy is unnecessarily consumed because of friction between the roller and densified material and the pressure between the roller and die, where there are no opening channels. The aim of this work was to attempt to eliminate a portion of the frictional and compaction energy consumption based on an improved method of densification using a ring die. An upgraded pellet mill was designed and manufactured with rams on its roller. When the die and the roller rotate in a fixed transmission ratio, the rams precisely press raw material into opening channels on the die. Experimental tests on its feasibility were carried out. The results showed that the pellet mill, with this improvement, worked without wear on the surface of either the ring die or the roller; furthermore, the density and mechanical durability of pellets were the same as those produced using the traditional method.
  • Researchpp 6586-6596Hua, F., Tong, S., Yang, R., Wang, B., and Yang, F. (2015). "Improved strength of peroxide-bleached deinked pulp after TEMPO-mediated oxidation at medium consistency," BioRes. 10(4), 6586-6596.AbstractPDF
    Deinked pulp was pretreated using the 4-acetamido-2,2,6,6,- tetramethyl-pipelidine-1-oxyl radical (TEMPO)/NaBr/NaClO system and then bleached using hydrogen peroxide to achieve a medium pulp consistency. The effect of the amount of oxidant NaClO addition on the peroxide bleaching of deinked pulp was studied. The treated pulp was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterization of XRD and SEM showed that the treated pulp had a higher degree of crystallinity and more fibrillation than untreated pulp. Fiber quality analysis also revealed that the treated pulps had more fines and shorter fiber length than the untreated pulp. A handsheet test showed that the deinked pulps pretreated with the TEMPO system exhibited high tensile index values. The tensile index of the TEMPO pretreated pulp was 17% higher than that of the pulp bleached by hydrogen peroxide alone.
  • Researchpp 6597-6609Hosseini, S. E., Bagheri, G., Abdul Wahid, M., and Saat, A. (2015). "Clean fuel, clean energy conversion technology: Experimental and numerical investigation of palm oil mill effluent biogas flameless combustion," BioRes. 10(4), 6597-6609.AbstractPDF
    The combustion of effluent biogas from a palm oil mill is not feasible on a large scale because of its low calorific value (LCV). Therefore, the captured biogas is usually flared because of a lack of appropriate combustion technology. However, such biogas could be an excellent source of energy for combined heat and power (CHP) generation in palm oil mills. In this paper, the feasibility of using biogas from palm oil mills in flameless combustion systems is investigated. In computational fluid dynamic (CFD) modeling, a two-step reaction scheme is employed to simulate the eddy dissipation method (EDM). In such biogas flameless combustion, the temperature inside the chamber is uniform and hot spots are eliminated. The peak of the non-luminous flame volume and the maximum temperature uniformity occur under stoichiometric conditions when the concentration of oxygen in the oxidizer is 7%. In these conditions, as the concentration of oxygen in the oxidizer increases, the efficiency of palm oil mill effluent biogas flameless combustion increases. The maximum efficiency (around 61% in the experiment) is achieved when the percentage of oxygen in the oxidizer is 7%.
  • Researchpp 6610-6623Yamamoto, A., Rohumaa, A., Kontturi, E., Hughes, M., and Vuorinen, T. (2015). "The effect of hydrothermal treatment on the color stability and chemical properties of birch veneer surfaces," BioRes. 10(3), 6610-6623.AbstractPDF
    The effects of hydrothermal pre-treatment on the color of silver birch veneer were determined. Spectrophotometric and chemical analyses of the veneer by means of extraction were conducted to determine the detailed chemical characteristics of the veneers. Results from spectrophotometric analysis revealed a significant increase in lightness (L*) and a decrease in yellowness (b*) in the veneer produced from a log soaked at 70 °C in short-term. Conversely, the effect of long-term storage resulted in a significant reduction in L* and an increase in b*. Chemical analyses of the veneer extract identified a moderate negative correlation between soluble proanthocyanidins content and treatment temperature. A higher amount of wood extractives, such as lipophilic extractives, free monosaccharides, and other organic substances, were obtained from wood material soaked at 70 °C than at 20 °C, which was most likely due to moderate chemical changes during treatment. Comparison of the results between dried veneers and wet veneers from the water extraction study revealed that the dried veneers had higher amounts of lipophilic matter and less water-soluble organic matter than the wet veneers. Other aspects of the loss of soluble proanthocyanidins in the birch veneer during plywood manufacturing are discussed.
  • Researchpp 6624-6634Li, X., Li, J., Li, J., and Gao, Q. (2015). "Effect of sepiolite filler in malamine-urea-formaldehyde resin on the properties of three-ply plywood," BioRes. 10(4), 6624-6634.AbstractPDF
    A low-cost sepiolite (SEP) was used to replace wheat flour (WF) as a filler applied to melamine-urea-formaldehyde (MUF) resin. Three-ply plywood was fabricated with different SEP/WF formulations, and its wet shear strength and formaldehyde emission were tested. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to explain why the performance of the plywood improved. Results showed that the wet shear strength of the plywood increased with the addition of SEP in the filler. When using SEP to replace 80% of the WF, the wet shear strength was improved by 27.8%, which was attributed to the penetration network with hydrogen bonds formed by SEP and MUF resin. Using SEP in the filler formulation created a smoother, denser, and more regular cross-section to prevent moisture intrusion, which improved the water resistance of the adhesive and thus further increased the wet shear strength of the resultant plywood. The tunnel structure of SEP could accelerate the free formaldehyde emission of the plywood. As a result, using SEP replace 80% WF as a filler, the formaldehyde emission of the plywood was reduced by 7.8% due to the tunnel release effect.
  • Researchpp 6635-6642Zhang, X., Yu, Y., Li, W., Ren, D., and Wang, H. (2015). "An efficient dispersive agent - KCl for ultrasonic preparation of microfibrillated cellulose (MFC)," BioRes. 10(4), 6635-6642.AbstractPDF
    The suitability of saturated salt solutions as a dispersive agent for preparing microfibrillated cellulose (MFC) from bamboo processing residue through ultrasonication was evaluated. The effect of pure water and KCl solution on the rheological behavior and morphologies of prepared MFC were compared. The results show that the viscosity of MFC suspension dispersed in KCl solution decreases by several orders of magnitude compared to the water counterpart. SEM images demonstrate that MFCs with comparable quality can be prepared using either pure water or KCl solution as a dispersive agent. A high concentration of bamboo processing residue (~2 wt.%) dispersed in salt solutions was found to possess comparable viscosity with a low concentration of MFC suspension (~0.5 wt.%) dispersed in water. This indicates that the application of salt solutions as dispersive agents in ultrasonication has great potential to improve the productivity of MFC prepared from plant materials.
  • Researchpp 6643-6662Ramasamy, G., Ratnasingam, J., Bakar, E. S., Halis, R., and Muttiah, N. (2015). "Assessment of environmental emissions from sawmilling activity in Malaysia," BioRes. 10(4), 6643-6662.AbstractPDF
    The sawmilling sector is the backbone of the Malaysian wood-based industry. Sawn timber is used extensively for further manufacturing of secondary wood-based products. The conversion of saw-logs into sawn timber releases several gases into the atmosphere, and these may contribute to environmental burdens as well as environmental impacts. Thus, this study aims to determine the environmental performance from gate-to-gate in the sawmilling industry using the life cycle assessment technique. Data pertaining to the saw-logs and energy consumption was calculated, and the environmental performance was assessed. The study focused on two different size sawmills and two tropical hardwood species. The findings concluded that several types of gases namely, CO2, CH4, NOx, N2O, SO2, and CO were discharged to the environment as a result of sawmilling processes. The discharge of these gases impacted the environment in the form of global warming, acidification, human toxicity, eutrophication, and photo-oxidant formation potentials.
  • Researchpp 6663-6675Borůvka, V., Gaff, M., Babiak, M., and Matúš, M. (2015). "Dimensional changes of veneer layered materials after cold pressing," BioRes. 10(4), 6663-6675.AbstractPDF
    Dimensional changes in both non-densified and densified, thin, wooden components and layered materials after external pressing forces were released were evaluated in this work. Densification was carried out using a cold process on a semi-automatic hydraulic pressing machine. The specimens’ dimensional stabilities, focusing mainly on their residual plastic deformations, were monitored. The impacts of several factors, such as wood species, material thickness, densification degree, and their combinations, were analyzed. Results showed that, with increased degree of densification, the relative plastic deformations (pressing degree) usually decreased. With regard to the compositions explored, the best combination was a top poplar layer densified by 10% plus a bottom beech layer densified by 20%. The impacts of each of the factors on the pressing degree values proved to be significant; the least significant was the bottom beech layer thickness and degree of densification. The greatest practical benefits can be obtained using the recommended combinations of composite layers.
  • Researchpp 6676-6689Gutiérrez-Soto, G., Medina-González, G. E., Treviño-Ramirez, J. E., and Hernández-Luna, C. E. (2015). "Native macrofungi that produce lignin-modifying enzymes, cellulases, and xylanases with potential biotechnological applications," BioRes. 10(4), 6676-6689.AbstractPDF
    With the aim of identifying and exploiting the mycological resources available in the Mexican Sierra Madre Oriental, the lignocellulolytic and pectinolytic potential of autochthonous fungi were evaluated in the present work. A solid media selection system was established in which 74 isolated strains were tested and compared to six international reference strains. The macrofungi Xylaria sp CS121, Inonotus sp CU7, Basidiomycete CH32, Basidiomycete CH23, Xylaria poitei, and Trametes maxima CU1 showed the highest cellulolytic and pectinolytic potential. The greatest lignolytic capability was exhibited by T. maxima CU1 and Pycnoporus sanguineus CS43. Under stirred submerged culture, T. maxima CU1 (cellulases, cellobiose dehydrogenase, manganese peroxidase (MnP), and laccase, with 200, 359, 51, and 267 U/L, respectively) and Xylaria sp CS121 (198 U/L of xylanases) were the highest enzymatic producers. Under stationary conditions, the best producers were Inonotus sp CU7 for cellulases, P. sanguineus CS43 for cellobiose dehydrogenase and laccase, and T. maxima CU1 for xylanases and MnP (242, 467, 35, 165, and 31 U/L, respectively). These results demonstrate the efficiency of enzymatic profiling as a tool for enzyme discovery with Mexican native fungi.
  • Researchpp 6690-6704Miranda de Lima, A. J., Iwakiri, S., and Lomelí-Ramírez, M. G. (2015). "Study of the interaction of Portland cement and Pinus wood for composites using Bragg sensors in optical fibers," BioRes. 10(4), 6690-6704.AbstractPDF
    The potential usage of Pinus wood residues in cement-wood composites and the behavior of CaCl2∙2H2O, used as an additive were assessed in this work. In order to improve the interaction between the cement-wood composites, CaCl2∙2H2O and 12 different pre-treatment types were tested. Pre-treatments involved extractions in cold and hot water, NaOH solutions, and several Ca(OH)2 concentrations for different times. An evaluation of the mechanical features (compressive strength and tensile resistances) of composites was also performed using 50 mm cylindrical samples. The interaction of the composites was analyzed using Bragg sensors in optical fibers. Pinus residues were tested having particle size of 4.8 mm and a CaCl2∙2H2O content between 0% and 8%. The highest compressive strength was observed for the production of composites with 4.5% CaCl2∙2H2O and the hot and cold water pre-treatment. Conversely, for tensile strength, the highest performance occurred when NaOH was used as a pre-treatment. The technology for determining the temperature of composites using Bragg sensors in optical fibers was judged to be efficient.
  • Researchpp 6705-6719Kaco, H., Zakaria, S., Chia, C. H., Sajab, M. S., and Mohd Saidi, A. S. (2015). "Characterization of aldehyde crosslinked kenaf regenerated cellulose film," BioRes. 10(4), 6705-6719.AbstractPDF
    Regenerated cellulose film with better mechanical properties was successfully produced by introducing aldehyde crosslinker during the regeneration process. The cellulose source material was derived from kenaf core powder and dissolved in LiOH/urea solvent at −13 °C to form a cellulose solution. The cellulose solution was cast and coagulated in a crosslinker bath at different percentages of glutaraldehyde (GA) and glyoxal (GX) to form a regenerated cellulose film. According to Fourier transform infrared spectroscopy (FTIR) spectra, the hydroxyl group of the cellulose was reduced, reducing the percentage of swelling as the percentage of crosslinker was increased. X-ray diffraction (XRD) patterns showed that the crystallinity index of the crosslinked film was decreased. The pore size of the films decreased as the percentage of crosslinker was increased, resulting in decreased film transparency. The pore volume and percentage of swelling in water of the films also increased with decreases in the pore size as the percentage of crosslinker was increased. The tensile strengths of the GA- and GX-crosslinked films increased by 20 and 15% with the addition of 20% of each crosslinker, respectively.
  • Researchpp 6720-6729Li, X., Li, X., Qi, W., Shi, J., Zhang, J., Xu, Y., and Pang, J. (2015). "Preparation of magnetic biomass-based solid acid catalyst and effective catalytic conversion of cellulose into high yields of reducing sugar," BioRes. 10(4), 6720-6729.AbstractPDF
    Using response surface method to determine the optimal technological conditions of biomass-based precursor preparation, magnetic Fe3O4 particles were loaded on the surface and internal channel of biomass-based precursor to prepare a magnetic biomass-based solid acid catalyst using the sol-gel method. To investigate the performance of the magnetic catalyst, it was used to hydrolyze cellulose into reducing sugar, whose structure was characterized by infrared spectrum analysis. The optimum process conditions of biomass-based precursor preparation was obtained by quadratic regression model as a carbonization temperature of 549 °C, carbonization time of 13 h, sulfonating temperature of 121 °C, and sulfonating time of 6 h. Using the biomass-based solid acid catalyst to hydrolyze cellulose, a reducing sugar yield of 57.36% was obtained. Compared with the traditional solid acid catalysts, the total reducing sugar yield was increased by 65%. The infrared spectrum analysis showed that magnetic Fe3O4 particles were combined successfully with biomass-based precursor. This magnetic biomass-based solid acid catalyst has a carbon structure layer of vermicular disorder and possesses high stability.
  • Researchpp 6730-6740Natarajan, R., and Al-Sinani, J. (2015). "Biodegradation of benzene, ethylbenzene, and xylene mixture in a date palm tree bark-based upflow biofilter," BioRes. 10(4), 6730-6740.AbstractPDF
    The performance of a date palm tree bark-based biofilter inoculated with mixed microbial consortia was investigated for the removal of a benzene- ethylbenzene-xylene mixture at a total inlet loading rate range of 38.0 to 612.0 g/m3·h. The influences of the inlet pollutant concentration and air flow rate were studied. The maximum elimination capacities attained for benzene, ethylbenzene, and toluene were 79.51, 77.47, and 57.08 g/m3·h, respectively. The removal efficiencies were evaluated and found to vary inversely with the inlet pollutant concentration. The VOC conversions were demonstrated by the difference in inlet and exit concentrations. The axial removal performance of the biofilter was studied, and the contribution of the lowest part was comparatively more than those of the upper sections because of the different biomass growth patterns. Temperature monitoring in the biofilter confirmed the exothermic nature of the biodegradation.
  • Researchpp 6741-6750Rahmat, B., Kurniati, F., and Hartini, E. (2015). "Mahogany wood-waste vinegar as larvacide for Spodoptera litura," BioRes. 10(4), 6741-6750.AbstractPDF
    The carbonization of lignocelullosic waste to obtain wood vinegar (WV) was investigated in this work. WV was used as a botanical insecticide against armyworm (Spodoptera litura), which is known as a major pest of soybean crops in Indonesia. This study includes the following: (i) the assessment of potential use of lignocellulosic waste from mahogany wooden-sandal home industry; (ii) the determination of the yield of various components of carbonization process, from each unit of the waste; and (iii) the application of the produced WV as larvicide on S. litura larvae in the laboratory. The experiments were arranged in a completely randomized design, and the observed variables included mortality and anti-feedant activity of S. litura larvae. The data were analyzed using analysis of variance with Duncan’s multiple differences test. The results showed that the amount of wood waste generated at wooden-sandal craftsman level was 16.12%. Carbonization of 1,000 g of the wood waste yielded WV, tar, bio-oil, and char in quantities of 442.68 g, 36.5 g, 4.04 g, and 251 g, respectively. The treatment using WV concentration of 1.5% to 3.0% showed low larvacidal action, which gave LC50 value of 12.82%, but it had adequate anti-feedant activity.
  • Researchpp 6751-6768Feng, D., Yu, H., Deng, H., Li, F., and Ge, C. (2015). "Adsorption characteristics of norfloxacin by biochar prepared by cassava dreg: Kinetics, isotherms, and thermodynamic analysis," BioRes. 10(4), 6751-6768.AbstractPDF
    Biochars (BC) generated from biomass residues have been recognized as effective sorbents for organic compounds. In this study, biochars as adsorbents for the removal of norfloxacin (NOR) from aqueous solutions were evaluated. Biochars were prepared from cassava dregs at 350 °C, 450 °C, 550 °C, 650 °C, and 750 °C, respectively (labeled as BC350, BC450, BC550, BC650, and BC750). The results showed that the kinetic data were best fitted to the pseudo second-order model, indicating that the sorption was governed by the availability of sorption sites on the biochar surfaces rather than the NOR concentration in the solution. Sorption isotherms of NOR were well described by the Freundlich model, and the Freundlich coefficients (lgkF) increased with the pyrolysis temperature of biochars. Thermodynamic analysis indicated the feasibility and spontaneity of the NOR adsorption process. The NOR adsorption on BC450, BC550, BC650, and BC750 was an endothermic process, while an exothermic process occurred for BC350. FTIR studies further suggested that the adsorption mechanism was possibly attributable to H-bond and π-π interactions between NOR and biochars. Overall, this work constitutes a basis for further research considering the bioavailability and toxicity of antibiotics in the presence of biochar.
  • Researchpp 6769-6782Li, D. L., Wu, J. Q., Peng, W. X., Xiao, W. F., Wu, J. G., Zhuo, J. Y., Yuan, T. Q., and Sun, R. C. (2015). "Effect of lignin on bamboo biomass self-bonding during hot-pressing: Lignin structure and characterization," BioRes. 10(4), 6769-6782.AbstractPDF
    To achieve high value-added utilization of lignin extracted from the biorefinery process in the wood composite industry, binderless particle boards were manufactured by bamboo materials combined with alkaline lignin (AL) in various proportions under various hot-pressing conditions. To elucidate the reactivity and chemical transformations of lignin macromolecules during the hot-pressing process, lignin samples were isolated from the corresponding boards and characterized by high-performance anion-exchange chromatography (HPAEC), gel permeation chromatography (GPC), quantitative 31P-NMR, and 2D-HSQC NMR. The best bonding strength (1.36 MPa) of the binderless particle boards was obtained under the conditions of 180 °C, pressure 5 MPa, and lignin/bamboo mass ratio 0.4. The molecular weight of the lignin samples decreased from 3260 to 1420 g/mol during hot-pressing. The NMR results showed that the contents of β-O-4' and β-β' linkages were reduced and β-5' linkages were increased as the hot-pressing temperature rose. Simultaneously, the percentage of G-type and H-type lignins as well as the content of phenolic OH increased.
  • Researchpp 6783-6796Wang, C., Xian, Y., Cheng, H., Li, W., and Zhang, S. (2015). "Tensile properties of bamboo fiber-reinforced polypropylene composites modified by impregnation with calcium carbonate nanoparticles," BioRes. 10(4), 6783-6796.AbstractPDF
    Tensile properties of bamboo fiber (BF)/polypropylene (PP) composites were investigated for different impregnation modification processes. The surface morphology of BF and the fracture morphology of the BF/PP composites were examined by scanning electron microscopy (SEM). Images showed that CaCO3 nanoparticles (nano-CaCO3) adhered to the fiber surfaces. Tension tests of individual bamboo fibers (IBFs) and the BF/PP composites were conducted. The results indicated that the tensile strength (TS), modulus of elasticity (MOE), and elongation at break (EAB) of IBFs increased by 16.0%, 22.2%, and 5.2%, respectively, while those of the BF/PP composites increased by 3.0%, 7.0%, and 15.8%, respectively, compared to the control samples. Various process parameters during the impregnation with nano-CaCO3 had marked effects on the tensile properties of the composites. The optimal conditions for BF-reinforced PP composites by impregnation modification were determined to be a nano-CaCO3 concentration of 1.0×10-2 g/mL, an ethylenediamine tetraacetic acid disodium salt (EDTA-2Na) additive concentration of 8.5×10-4 g/mL, and an impregnation time of 25 min.
  • Researchpp 6797-6808Sofuoglu, S. D. (2015). "Using artificial neural networks to model the surface roughness of massive wooden edge-glued panels made of Scotch pine (Pinus sylvestris L.) in a machining process with computer numerical control," BioRes. 10(4), 6797-6808.AbstractPDF
    An artificial neural network (ANN) approach was employed for the prediction and control of surface roughness (Ra and Rz) in a computer numerical control (CNC) machine. Experiments were performed on a CNC machine to obtain data used for the training and testing of an ANN. Experimental studies were conducted, and a model based on the experimental results was set up. Five machining parameters (cutter type, tool clearance strategy, spindle speed, feed rate, and depth of cut) were used. One hidden layer was used for all models, while there were five neurons in the hidden layer of the Ra and Rz models. The RMSE values were calculated as 1.05 and 3.70. The mean absolute percentage error (MAPE) values were calculated as 20.18 and 15.14, which can be considered as a good prediction. The results of the ANN approach were compared with the measured values. It was shown that the ANN prediction model obtained is a useful and effective tool for modeling the Ra and Rz of wood. The results of the present research can be applied in the wood machining industry to reduce energy, time, and cost.
  • Researchpp 6809-6818Zhang, Y., and Yu, W. (2015). "Changes in surface properties of heat-treated Phyllostachys pubescens bamboo," BioRes. 10(4), 6809-6818.AbstractPDF
    The wetting phenomena and surface energetic behavior in heat-treated bamboo were studied. The bamboo specimens were heat-treated at temperatures of 100, 140, and 180 °C for 4 h, and an untreated sample served as a control. The sessile drop technique was used to estimate the surface contact angles of the control and heat-treated bamboo samples. The contact angle data were then used to determine the surface free energies using the Lifshitz-van der Waals/acid-based approach. The results revealed that the heat treatment process affects surface wettability. Heat treatment at 100 to 180 °C increased the contact angle of distilled water and formamide, but heat treatment did not cause any increase in the contact angle of diiodomethane. The hydrophobic characteristics of the bamboo surfaces also increased under heat treatment, and the surface free energy and the polarity of the bamboo decreased. Surface analysis by XPS of the samples heat-treated at 180 °C showed a decreased O/C ratio and increased C1 peak, indicating that more lignin and extractives were situated on the bamboo surface. Changes in wettability can greatly impact the use of the material, particularly with respect to the adhesion of paints and coatings.
  • Researchpp 6819-6829Zhang, S., Zhang, Y., Liu, L., and Fang, G. (2015). "Antioxidant activity of organosolv lignin degraded using SO42-/ZrO2 as catalyst," BioRes. 10(4), 6819-6829.AbstractPDF
    Organosolv lignin degradation was carried out through hydrogenolysis routes with SO42-/ZrO2 as the catalyst. Structural characterization and antioxidant activity of organosolv lignin samples were investigated; the antioxidant activity of the organosolv lignin was compared with that of soda lignin. Results showed that the active functional groups contents of organosolv lignin were increased, and the antioxidant activity of organosolv lignin was improved. The total hydroxyl and phenolic hydroxyl group contents of organosolv lignin were increased by 15.81% and 26.55%, respectively, and the Mw was decreased from 5739 g/mol to 4499 g/mol. The IC50 of organosolv lignin on DPPH radicals scavenging rate, ABTS+ radicals scavenging rate, and reducing power were decreased by 18.91%, 18.08%, and 8.48%, respectively. The catalyzed organosolv lignin can be used as a natural antioxidant for functional food or in cosmetic and polymeric materials.
  • Researchpp 6830-6860Essoua Essoua, G. G., Blanchet, P., Landry, V., and Beauregard, R. (2015). "Maleic anhydride treated wood: Effects of drying time and esterification temperature on properties," BioRes. 10(4), 6830-6860.AbstractPDF
    To improve technical performance of wood siding, treatment with maleic anhydride was applied. The effects on technical performance of drying time and esterification temperature parameters were analyzed. Wood samples of lodgepole pine and white pine were treated and tested. Results indicated that treatment improves technical performance of wood (dimensional stability, fungal degradation resistance, and accelerated aging). FTIR spectroscopy analysis showed spectra with peaks at 1750 to 1730 cm-1. These correspond to ester bonds formed between wood hydroxyl groups and MA carboxylic acid groups. SEM images indicate that the MA quantity in wood cavities was increased with decreasing esterification temperature. Weight percent gain (WPG) increased with decreasing time and temperature of esterification. Artificial aging and fungal degradation performances were monitored using FTIR analysis. Esterification temperature had no important effect on fungal degradation. Weight loss after fungal exposure of treated samples was not only due to fungal action but also due to evaporation of MA during the drying step. Regarding artificial aging, degradation of wood components and ester bonds were less for samples esterified at 180 °C than those esterified at 160 °C or 140 °C.
  • Researchpp 6861-6871Fan, H., Wang, X., Liu, J., and Xu, B. (2015). "Study of coating weight and utilization rate in the modification of ground calcium carbonate," BioRes. 10(4), 6861-6871.AbstractPDF
    Ground calcium carbonate (GCC) was modified in this work using starch, sodium stearate, and sodium hexametaphosphate. The effects of reaction temperature and the dosage of sodium hexametaphosphate on the coating weight of modified GCC and the utilization rate were considered. The strength (tensile, burst, and tear) of papers filled with modified GCC vs. unmodified GCC was compared. The research showed that lower precipitation reaction temperature was conducive to the increase of modified GCC coating weight and the complex utilization rate. A proper dosage of sodium hexametaphosphate could effectively increase the coating weight of modified GCC and the complex utilization rate. Compared with unmodified GCC filled papers, modified GCC filled papers performed better with respect to paper strength, but the optical properties (brightness and opacity) showed the opposite trend.
  • Researchpp 6872-6885Chen, R. S., Salleh, M. N., Ab Ghani, M. H., Ahmad, S., and Gan, S. (2015). "Biocomposites based on rice husk flour and recycled polymer blend: Effects of interfacial modification and high fibre loading," BioRes. 10(4), 6872-6885.AbstractPDF
    Biocomposites were prepared with rice husk flour (RHF) (raw and alkali-treated) in a recycled polymer blend (RPB) using a co-rotating twin screw extruder. Modifications to the composite were carried out through fibre surface treatment with 4 wt.% sodium hydroxide (NaOH) and 3 wt.% maleic anhydride polyethylene (MAPE) coupling agent. Fourier transform infrared (FTIR) analyses of raw and NaOH-treated RHF were performed. The effects of the interfacial modification (MAPE or/and NaOH) and filler loading (50 to 80 wt.%) on the mechanical, physical, and morphological properties were investigated. Improvements in the tensile strength and Young's modulus as well as reduction in water absorption and water loss were observed for raw RHF composites incorporated with MAPE. Alkalisation of fibres resulted only in an enhancement in elongation and impact strength. The composite with 70 wt.% RHF modified with only MAPE exhibited the highest tensile strength and modulus, 22.2 and 711.6 MPa, respectively. The general trend of the composite results exhibited some decrease in water absorption and water loss from untreated RHF composites with only MAPE modification as compared to the NaOH-treated composite, although a rougher surface for the treated fibres was revealed in SEM images.
  • Researchpp 6886-6895Yavari, A., Hemmasi, A., Roohnia, M., and Marušák, R. (2015). "Dynamic Young's modulus of scarf- and finger-jointed beams using longitudinal vibration method," BioRes. 10(4), 6886-6895.AbstractPDF
    The elastic properties of oak wood (solid wood, scarf-jointed beams, and finger-jointed beams) and two different, independently applied adhesives (polyvinyl acetate and isocyanate) were investigated. Using a longitudinal vibration technique and comparing the elastic modulus of the solid wood and jointed beams, it was revealed that longer fingers (10 mm) in the finger joints and larger angle joints (70° and 75°) in the scarf-jointed beams enhanced the elastic properties of the beams. Based on these findings, it was concluded that these configurations result in elastic properties that are most similar to those of solid wood. The application of polyvinyl acetate rather than isocyanate significantly (P < 0.05) improved the elastic properties of the joints (both scarf- and finger-jointed beams).
  • Researchpp 6896-6905Gava, M., Müzel, S. D., de Lima, L. R., Barbosa, J. C., Garcia, J. N., Ferreira, B. S., Filho, H. J. S., Bernardes, M. S., and De Araujo, V. A. (2015). "Production of particleboards from Hevea brasiliensis clones and castor oil-based polyurethane resin," BioRes. 10(4), 6896-6905.AbstractPDF
    The economic exploitation of rubber tree (Hevea brasiliensis) usage is primarily directed toward latex extraction. After the productive life of the rubber tree forest, the managed area is harvested for planting reformulation. The harvested wood is most often used for energy generation purposes. The aim of this work was to study the feasibility of using rubberwood waste and castor oil-based polyurethane resin in the production of particleboards. Homogeneous and heterogeneous panels were made with nominal dimensions of 500 x 500 mm and thicknesses of 10 mm using particles from GT1 and RRIM600 clones of the rubber tree and 12% castor oil-based polyurethane adhesive. The panels were pressed at 140 °C for 12 min with 40 kgf/cm2 specific pressure. Density, moisture content, thickness swelling, water absorption for 2 and 24 h, static bending, and internal bonding determinations were performed according to the Brazilian Standard (NBR) 14810-3 (2006) for the physical-mechanical panel characterization. The results show that using Hevea brasiliensis in particleboard production is viable. However, multilayer boards exhibited better results.
  • Researchpp 6906-6916Leminen, V., Mäkelä, P., Tanninen, P., and Varis, J. (2015). "Leakproof heat sealing of paperboard trays - Effect of sealing pressure and crease geometry," BioRes. 10(4), 6906-6916.AbstractPDF
    The leakproof sealing of paperboard trays depends on factors such as the quality of the sealed tray and the parameters of the sealing process. Leakproof sealing is critical when food products are packed, as poor sealing can result in leakage and cause a reduction in the microbiological quality and sensory shelf life of packed food products. In this paper, factors affecting the leakproof sealing of paperboard trays, such as sealing pressure and the geometry of creases in the trays, were investigated. Trays were sealed with varied sealing pressure and temperature, and the sealed trays were inspected using a coloring solution test, oxygen content measurements, and microscopic analysis. The results show that the sealing pressure is a critical parameter in the sealing process. The minimum sealing pressure that resulted in leakproof within the materials investigated was 1.8 N/mm2. The depth of crease that can be sealed in a leakproof manner was found to be up to 150 µm.
  • Researchpp 6917-6927Wang, W., Peng, Y., Zhang, W., and Li, J. (2015). "Effect of pentaerythritol on the properties of wood- flour/polypropylene/ammonium polyphosphate composite system," BioRes. 10(4), 6917-6927.AbstractPDF
    Intumescent, flame-retarding wood-flour/polypropylene composites (WPCs) having different ammonium polyphosphate/pentaerythritol (APP/PER) ratios (4/1, 3/1, and 2/1) were prepared in this study. The thermal degradation behavior, flame retardancy, and mechanical properties of the composites were tested. Moreover, the residues of the WPCs were observed by scanning electron microscopy, and the flame retardancy mechanism was investigated. The results showed that WPC/APP/PER exhibited higher thermal stability in the high temperature region and left much more char residue than WPC/APP, according to thermogravimetric analysis. Limiting oxygen index and cone calorimetry tests showed that the addition of PER improved the flame retardancy of the WPCs, especially when APP/PER ratio was 3/1. However, because of the poor compatibility with the composite matrix and uneven dispersion in the WPCs, the incorporation of PER decreased the mechanical performance of WPCs obviously.
  • Researchpp 6928-6941Zhang, Z., Ding, H., Shi, D., Xia, L., and Zhu, M. (2015). "Lignin-induced expression of Aspergillus oryzae 5992 genes using suppression subtractive hybridization," BioRes. 10(4), 6928-6941.AbstractPDF
    A previous study reported that a novel Aspergillus oryzae strain (CGMCC5992) can synthesize lignin hydrolytic enzymes for lignin degradation from straw. The present work involves the different gene expression of A. oryzae 5992 grown in media using lignin and glucose as carbon sources by suppression subtractive hybridization. Surprisingly, peroxidase was found in up-regulation genes, which is the key enzyme for degrading lignin. This shows that A. oryzae 5992 can secrete peroxidase in the presence of lignin. The functions of up-regulation genes also included gluconeogenesis, repairs, as well as signal and transporter proteins in the cell membrane. In addition, the down-regulation of genes was closely related to the aerobic metabolism of glucose, the fatty acid synthesis of the cell membrane, and the synthesis and utilization of ATP. Therefore, A. oryzae could regulate metabolism using lignin as carbon source, including lignin degradation promotion, glucose metabolism inhibition, and glucose regeneration.
  • Researchpp 6942-6952Espinoza, O., Buehlmann, U., and Laguarda-Mallo, M. F. (2015). "Thermally modified wood: Marketing strategies of U.S. producers," BioRes. 10(4), 6942-6952.AbstractPDF
    Thermally-modified wood (TMW) has enhanced properties and its production does not involve the use of chemicals. However, the adoption of TMW in the marketplace has been limited in the U.S. for reasons that have not yet been clearly established. In this study, the marketing practices of U.S. producers and distributors of TMW were investigated, by conducting semi-structured interviews. Topics included major products and species, markets, distribution channels, promotional strategies, perceived barriers to adoption, and the outlook for TMW markets. Results show that TMW producers in general export a significant percent of their production; that TMW is considered a high-end product; and that customers are not as sensitive to prices as in other mainstream markets. Common products sold include siding, decking, flooring, millwork, and components for musical instruments. Respondents believe that the low awareness of TMW among the American public is a major barrier to wider adoption of TMW. However, companies envision a bright future for TMW as sales and inquiries have increased at a fast rate during the last few years.
  • Researchpp 6953-6960Zhang, M., Liu, Y., and Yang, Z. (2015). "Correlation of near infrared spectroscopy measurements with the surface roughness of wood," BioRes. 10(4), 6953-6960.AbstractPDF
    The surface roughness of Chinese fir and Eucalyptus wood samples were measured using the stylus profile method in order to investigate the correlation between near infrared (NIR) spectroscopy and surface roughness. The results showed that the NIR spectra absorption showed differences among samples from different surface roughnesses, and the absorption decreased with the increase of the surface roughness. A strong relationship was found between the surface roughness parameters, i.e., the arithmetical mean deviation of the profile (Ra), the ten-point height of irregularities (Rz), and the maximum height of profile (Ry). Based on the NIR spectra of the Chinese fir wood samples and the mixed wood samples of the two wood species, and the correlation coefficients of these two types of wood samples in a calibration set were 0.77 to 0.83 and 0.67 to 0.74, respectively. A relatively poor correlation was found in the model based on the Eucalyptus samples; however, it was still significant. These results suggested that there was relative information about the surface roughness from the NIR spectra, which further illustrated that the surface roughness may influence the effect of models for wood properties built by NIR data.
  • Researchpp 6961-6974Wahyu, H., Jang, J. H., Park, S. H., Qi, Y., Febrianto, F., Lee, S. H., and Kim, N. H. (2015). "Effect of temperature and clamping during heat treatment on physical and mechanical properties of Okan (Cylicodiscus gabunensis [Taub.] Harms) wood," BioRes. 10(4), 6961-6974.AbstractPDF
    The objective was to evaluate the effect of temperature and clamping method during heat treatment on the properties of high density Okan wood. Heat treatment of sapwood and heartwood was conducted using an electric oven with a programmable controller at 160 °C, 180 °C, 200 °C, and 220 °C for 2 h. Physical and mechanical properties were compared before and after the heat treatment process. The color change (DE*), weight loss, and volume shrinkage increased with increasing temperature, whereas the equilibrium moisture content (EMC) and water absorption (WA) decreased in both types of wood. The wood density was not affected by temperature, and the magnitude of DE* in sapwood was the highest, while the magnitude of weight loss, volume shrinkage, EMC, and WA in heartwood was higher than in sapwood. The clamping method affected DE* in heartwood only, while the weight loss, volume shrinkage, EMC, and WA was affect in both types of wood. A significant reduction in the mechanical properties occurred after heat treatment at 200 °C and 220 °C. The reduction of MOR, MOE, and shear strength in heartwood was greater than in sapwood, while the compressive strength reduction in sapwood was the highest.
  • Researchpp 6975-6992Main, N. M., Talib, R. A., Ibrahim, R., Abdul Rahman, R., and Mohamed, A. Z. (2015). "Linerboard made from soda-anthraquinone (soda-AQ) treated coconut coir fiber and effect of pulp beating," BioRes. 10(4), 6975-6992.AbstractPDF
    The performance of coir fiber in the production of linerboard made from soda-anthraquinone (soda-AQ) pulp was evaluated. Based on chemical analysis, the composition of coir fiber is suitable for the pulping process. Out of nine pulping conditions characterized, a pulping condition of 18% active alkali for 90 min cooking time was chosen. These conditions provided the highest screened yield (48.99%), a low rejection yield (0.27%), high viscosity (11.73 cP), and a kappa number (41) that is acceptable for unbleached linerboard production. Beating strengthened the coir pulp. Analyzing the beating revealed that coir pulp was optimized at 1000 to 2000 revolutions, based on a graph of freeness vs. burst index. For all beating conditions (1000 to 8000 revolutions), FESEM micrographs showed the presence of internal and external fibrillation of the fiber, which gradually increased fiber conformability and improved the inter-fiber bonding within the paper formation. Based on its burst strength of 4.57 kPa.m2/g and ring crush test of 1.76 Nm2/g, which complies with the minimum requirement of the industry standard, coir fiber can be considered an alternative fiber source for linerboard production.
  • Researchpp 6993-7008Su, W., Yang, Y., Dai, H., and Jiang, L. (2015). "Biosorption of heavy metal ions from aqueous solution on Chinese fir bark modified by sodium hypochlorite," BioRes. 10(4), 6993-7008.AbstractPDF
    The oxidation conditions and adsorption ability of Cu (II), Cd (II), and Pb (II) from an aqueous solution of sodium hypochlorite-oxidized fir bark powder were investigated. The optimum amount of NaClO was 9.6%, the pH was 9, and the oxidation time was 120 min. Batch adsorption experiments were carried out with various times, pH values, and initial metal ion concentrations. The adsorption isotherms and kinetics of adsorption were also studied. The maximum adsorption capacity of oxidized fir bark was 0.983, 1.223, and 0.966 mmol/g for Cu (II), Cd (II), and Pb (II), respectively, within 30 min at pH 5, higher adsorption capacity than that of unoxidized fir bark. The isothermal adsorption of heavy metal ions in aqueous solution was a good fit to the Langmuir equation, with a coefficient of determination, R2, above 0.99. The adsorption of fir bark on metal ions can be appropriately approximated by a pseudo-second order adsorption kinetics model. Results indicate that the fir bark powder modified with sodium hypochlorite can adsorb large amounts of metal ions and could be a good adsorbent for the removal of Cu(II), Cd(II), and Pb(II) from aqueous solution.
  • Researchpp 7009-7020Kasal, A., Eckelman, C. A., Haviarova, E., Erdil, Y. Z., and Yalcin, I. (2015). "Bending moment capacities of L-shaped mortise and tenon joints under compression and tension loading," BioRes. 10(4), 7009-7020.AbstractPDF
    Tests were carried out to determine the bending moment capacities of L-shaped mortise and tenon furniture joints under both compression and tension loadings. The effects of wood species (Turkish beech and Scotch pine), adhesive type (polyvinylacetate and polyurethane), and tenon size (width and length) on the static bending moment capacity of joints under the same loading conditions were investigated. The results of the tests indicated that the moment capacity increased as either tenon width or length increased. The results also indicated that tenon length had a greater effect on the moment capacity than tenon width. In both compression and tension tests, Turkish beech joints were stronger than Scotch pine joints, and PU joints were stronger than PVA joints. An empirically derived expression was developed to estimate the average ultimate bending moment capacity of joints under compression and tension loads as functions of the wood species, the adhesive type, and the tenon size.
  • Researchpp 7021-7037Wang, S., You, T., Xu, F., Chen, J., and Yang, G. (2015). "Optimization of [Amim]Cl pretreatment conditions for maximum glucose recovery from hybrid Pennisetum by response surface methodology," BioRes. 10(4), 7021-7037.AbstractPDF
    Because of a complex chemical ultra-structure of lignocellulosic biomass, pretreatment is a necessary step for its conversion into bio-ethanol. In the present study, pretreatment conditions using the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([Amim]Cl) were optimized for a relatively new model energy crop, hybrid Pennisetum (P. americanum × P. purpureum) to maximize the yield of fermentable sugars (glucose). The design of experiment programs employed a central composite design (CCD), with variables of temperature (102 to 187 °C), retention time (0.5 to 5.5 h), and solids loading (2 to 15 wt%). These factors were further optimized using response surface methodology (RSM). The proposed quadratic model to predict the glucose recovery from hybrid Pennisetum was verified by variance analysis (ANOVA). The model displayed high F and R2 values, indicating that it could be successfully used to identify the relationship among the independent variables studied. A maximum glucose recovery of 72.2% was found with temperature conditions of 139 °C, 2.97 h retention time, and 9.1 wt% solids loading.
  • Researchpp 7038-7052Chen, X., Xia, N., Guo, K., and Qi, C. (2015). "Dry bond strength and water resistance of konjac glucomannan, chitosan, and polyvinyl alcohol blend adhesive," BioRes. 10(4), 7038-7052.AbstractPDF
    An environmentally-friendly wood adhesive was developed by blending konjac glucomannan (KGM), chitosan (CH), and polyvinyl alcohol (PVA) together. The viscosity of the KGM-CH-PVA (KCP) blend adhesive was determined, and the morphology of the film was observed using scanning electron microscopy (SEM). The KCP blend adhesive was applied to plywood during the manufacturing process, and the effects of the KGM, CH, and PVA contents on the bond strength was investigated. Results showed that KGM greatly increased the viscosity of the KCP blend adhesive, whereas the addition of PVA decreased the viscosity in the test range. The SEM observations showed that the KCP blend adhesive was homogeneous. The bond strength of the plywood that was treated with KCP blend adhesive increased with increasing KGM and CH concentrations, and desirable performance could be obtained with a total solids content of 4.6%. The KCP blend adhesive with 2.0% KGM, 2.0% CH, and 0.6% PVA exhibited a comparable bond strength with phenol formaldehyde. Findings suggest that the KCP blend adhesive can be used as a wood adhesive with all raw materials, having the advantage of being environmentally friendly.
  • Researchpp 7053-7064Zheng, R., Tshabalala, M. A., Li, Q., and Wang, H. (2015). "Weathering performance of wood coated with a combination of alkoxysilanes and rutile TiO2 heirarchical nanostructures," BioRes. 10(4), 7053-7064.AbstractPDF
    The weathering performance of wood coated with a combination of rutile TiO2 hierarchical nanostructures and a sol-gel deposit of alkoxysilanes was determined by exposing three sets of specimens to UV light and water spray. The first set consisted of specimens coated with a mixture of methyltrimethoxysilane (MTMOS) and hexadecyltrimethoxysilane (HDTMOS). The second set consisted of specimens coated with nanostructural TiO2 followed by a mixture of MTMOS and HDTMOS. The third set consisted of uncoated control specimens. The wood coated with TiO2 followed by a mixture of MTDMOS and HDTMOS exhibited significantly less surface color change and weight loss as a result of UV light-induced degradation and erosion from water spray in comparison with the other groups. However, the coated surfaces were gradually transformed from hydrophobic to hydrophilic. Despite this apparent weakness, the MTMOS/HDTMOS/TiO2 coating, with superior photostabilization properties and resistance to surface erosion, may be useful for improving the weathering performance of wood coated with semi-transparent wood stains.
  • Researchpp 7065-7080Li, H. T., Su, J. W., Deeks, A. J., Zhang, Q. S., Wei, D. D., and Yuan, C. G. (2015). "Eccentric compression performance of parallel bamboo strand lumber columns," BioRes. 10(4), 7065-7080.AbstractPDF
    The influence of eccentricity ratio on the behaviour of 50 parallel bamboo strand lumber (PBSL) column specimens was studied under eccentric compression. The load-strain and load-deflection relationships were obtained from column tests, and the detailed failure modes for all specimens are reported. The eccentricity ratio is the main influencing factor on the bearing capacity of the columns, and the ultimate load values decreased with an increase of the eccentricity ratio. Both the ultimate middle deflection values and the absolute ultimate longitudinal strain values initially increased with the increase of the eccentricity ratio, and then stabilized or decreased slightly when the eccentricity ratio was bigger than approximately 0.8. The absolute ultimate lateral strain values for both face A (bracket side or compression side) and face C (tension side) performed similarly with the increasing of eccentricity ratios, increasing initially and then stabilizing or decreasing slowly. An equation for calculating the eccentricity influencing coefficient of PBSL columns is proposed. The calculation results obtained from the equations agreed well with the test results.
  • Researchpp 7081-7091Seo, H. J., Jeong, S. G., and Kim, S. (2015). "Development of thermally enhanced wood-based materials with high VOCs adsorption using exfoliated graphite nanoplatelets for use as building materials," BioRes. 10(4), 7081-7091.AbstractPDF
    Wood-based materials are used to manufacture various types of panels, including particleboard, fiberboard, and plywood, and they can also be used to manufacture furniture as well as interior and exterior building materials. However, wood-based materials exhibit a number of problems, including the emission of indoor air pollutants from adhesives used during production and their inherent fire risk. To date, a number of studies have investigated the emission of indoor air pollutants, and in recent years, there has been an increasing amount of interest in the flame-retardant performance of wood-based materials. In this study, the use of carbon materials was studied to improve the flame-retardant performance of wood-based materials. A comparison was made with various methods that are currently in use. The thermal conductivity was measured by the TCi method developed by C-Therm Technologies Ltd to evaluate the energy characteristics of wood-based materials that are used as interior materials.
  • Researchpp 7092-7104Yang, L., Jiang, T., Liu, H., and Li, K. (2015). "Effects of different drying treatments on preservation of organic compounds in Dalbergia bariensis wood," BioRes. 10(4), 7092-7104.AbstractPDF
    Rosewood furniture and handicrafts are appreciated by Chinese people on account of their rich aroma and pleasing feel. The unique characteristics of rosewood are attributed to the presence of certain organic compounds in its gum canal and parenchyma cells. However, modern wood drying is different from traditional technology with respect to protecting those valuable organic compounds in wood. In this study, to investigate the valuable organic compounds in Dalbergia bariensis, and the effect of drying treatments on their preservation rates, wood extracts, untreated and treated with conventional drying (CD), vacuum drying (VD), and vacuum freeze drying (VFD), were analyzed by gas chromatography- mass spectrometry (GC-MS). The results indicated that there were some compounds with obvious pharmaceutical functions in Dalbergia bariensis, which can be used to improve the furniture function in health care. Also, the preservation of these compounds was affected by drying treatment; VFD drying preserved the maximum amount of organic compounds in wood.
  • Researchpp 7105-7122Li, H., Pan, Y., Chang, S., Du, R., Li, P., and Li, S. (2015). "Transcriptomic analysis of Clostridium thermocellum in cellulolytic consortium after artificial reconstruction to enhance ethanol production," BioRes. 10(4), 7105-7122.AbstractPDF
    The cellulolytic and ethanologenic bacterial community is a promising candidate for the production of bioethanol from lignocellulose. In this study, by artificially changing the ratio of Clostridium thermocellum in the cellulolytic consortium H, ethanol production was increased by 72.7%. Metatranscriptomic analysis was used to elucidate the contribution of Clostridium thermocellum to ethanol production. A comprehensive analysis of genes mapped to the Clostridium thermocellum ATCC 27405 genome was performed; the identified gene expression differences related to cellulosic ethanol pathways were carefully studied. The results indicated that the majority of genes involved in lignocellulose degradation, sugar transport, cellodextrin breakdown, glycolysis, and ethanol synthesis were up-regulated in C. thermocellum when added to H (HCt). More than 18 cellulosome-related genes had 15-fold or greater increased expression. The results illustrate the role of C. thermocellum in the cellulolytic consortium H and HCt and provided useful information for identifying genes and preferred pathways. These results will aid in the metabolic and genetic engineering of bacterial strains for more efficient biofuel production.
  • Researchpp 7123-7135Kminiak, R., Gašparík, M., and Kvietková, M. (2015). "The dependence of surface quality on tool wear of circular saw blades during transversal sawing of beech wood," BioRes. 10(4), 7123-7135.AbstractPDF
    The article deals with the influence of the tool wear of several circular saw blades, each with different numbers of teeth (24, 40, and 60), on the quality of a machined wood surface. The surface quality was evaluated based on the surface roughness, which was represented by the surface arithmetical mean deviation Ra. To achieve the conditions of manual sawing, the saw blade was shifted into the cut with a constant feed force of 15 N. The results showed that the 40-tooth saw blade obtained the most suitable results; it exhibited the longest sawn distance and reached moderately good values of tool wear. The average values of surface roughness ranged from 3.9 to 14.5 µm, and the saw blade wear increased proportionally with sawn distance. The tool wear of the saw blade had no unambiguous effect; increase in tool wear did not lead to a deterioration of surface quality.
  • Researchpp 7136-7150Abdel-Halim, E. S., Alanazi, H. H., and Alghamdi, A. A. (2015). "Extraction and bleaching of olive tree branch cellulose," BioRes. 10(4), 7136-7150.AbstractPDF
    The objective of this work was to extract and bleach cellulose from a low-value agricultural waste, namely, olive tree branches. The extraction procedure began by subjecting finely powdered olive tree branches to alkaline treatment, using different concentrations of sodium hydroxide solution to remove/dissolve the non-cellulosic cementing constituents, such as pectin, hemicelluloses, and natural waxes from the structure of this lignocellulosic network. The second step of the extraction procedure was the oxidation/bleaching treatment, and for this purpose, a powerful oxidizing agent composed of sodium chlorite/triethanolamine salt was used. All factors and conditions affecting the bleaching reaction, including triethanolamine salt concentration, bleaching temperature, and utilization of different triethanolamine salts, were extensively studied. The efficiency of the bleaching/oxidation treatment was evaluated by recording the FTIR spectra of the samples before and after extraction and analyzing the bleached samples to estimate the carboxyl content, loss in weight, and whiteness index.
  • Researchpp 7151-7164Atar, M., Cinar, H., Dongel, N., and Yalinkilic, A. C. (2015). "The effect of heat treatment on the pull-off strength of optionally varnished surfaces of five wood materials," BioRes. 10(4), 7151-7164.AbstractPDF
    This study investigated the effects of heat treatment, following optional treatment with synthetic, water-based, and alkyd varnishes, on the pull-off strength of wooden materials sampled from oriental beech (Fagus orientalis L.), oak (Quercus petraea Liebl.), black poplar (Populus nigra L.), pine (Pinus sylvestris L.), and fir (Abies bornmulleriana M.). The test samples were subjected to heat treatment at temperatures of 165 °C and 175 °C for periods of 2 and 4 h with a total of 4 variations. With respect to the wood type, the samples of beech wood yielded the highest results for pull-off strength, while fir wood yielded the lowest. With respect to the varnish types, the highest pull-off strength was found in the samples of synthetic varnished beech (5,452 with a 37.2% improvement) at 175 °C heat treatment for 4 h, while the lowest results were obtained in the samples of fir (0.991 with a 48.5% decrease) at 175 °C heat treatment for 4 h. In conclusion, heat treatment significantly decreased the pull-off strength of the woods.
  • Researchpp 7165-7177Abdalla, S., Pizzi, A., Bahabri, F., and Ganash, A. (2015). "Analysis of valonia oak (Quercus aegylops) acorn tannin and wood adhesives application," BioRes. 10(4), 7165-7177.AbstractPDF
    The coupling of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry with 13C nuclear magnetic resonance (NMR) is a suitable method for examining the composition of hydrolysable tannins and has been applied to the investigation of valonia oak (Quercus aegylops) acorn tannin extract. Such methods can determine the extract’s structural aspects and other characteristics. It was determined that valonia oak acorn tannin extract is composed of mainly pentagalloylglucose structures; their rearrangement structures, vescalagin/castalagin (with linkages to flavogallonic acid) and vescalin/castalin; ellagic acid and vescavaloneic/castavaloneic acid; and free gallic acid and glucose. Traces of catechin gallate were also observed in this tannin extract. The tannin from acorns of valonia oak was used to substitute up to 50% of the phenol used in the preparation of phenolic resins as adhesives for wood particleboard. These phenol-tannin-formaldehyde resins showed comparable performance to phenol-formaldehyde resins.
  • Researchpp 7178-7187Niu, H., Kong, X., Li, L., Sun, Y., Yuan, Z., and Zhou, X. (2015). "Analysis of biogas produced from switchgrass by anaerobic digestion," BioRes. 10(4), 7178-7187.AbstractPDF
    Material flow analysis (MFA) was applied to study the process of biogas production from switchgrass using a mid-temperature (35 ± 1 °C) batch anaerobic digestion process. The flow distributions of energy and material, including carbon (C) and nitrogen (N), were analyzed, as were the material and energy conversion efficiencies. The results showed that biogas and CH4 production were 268.80 and 135.31 NmL×gVS-1 added, respectively, and the average CH4 content in biogas was 50.34%. Based on the MFA of the anaerobic digestion process, 30.6%, 3.6%, and 65.8% of C was converted into biogas, biogas slurry, and biogas residue, respectively; and 11.7% and 88.3% of N was converted into biogas slurry and biogas residue, respectively. The conversion efficiencies of the material and energy from switchgrass to biogas were 36.1% and 30.1%. Because of the low conversion efficiencies of matter and energy during biogas production, it is necessary to strengthen the secondary use of the fermentation residue. This study provides a basis for the optimization of the anaerobic digestion process and efficient utilization of resources and energy of energy-grass.
  • Researchpp 7188-7202Choi, E. H., Kim, C. H., Youn, H. J., and Lee, H. L. (2015). "Influence of PVA and CMC on the properties of pigment coating colors and their effects on curtain stability," BioRes. 10(4), 7188-7202.AbstractPDF
    The influence of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) on the properties of ground calcium carbonate (GCC) and clay coating colors, as well as its effect on curtain stability during the coating process was investigated. Based on the experimental results of the zeta potential, sediment porosity, rheological measurements, the floc formation mechanisms of the cobinders were proposed. The zeta potential decreased with an increase in the amount of added PVA, while it barely changed when CMC was added. This was attributed to the adsorption of PVA onto the pigment surface, while the adsorption of CMC was hindered by electrostatic repulsion. CMC cobinder increased the low-shear viscosity, but it resulted in relatively low viscosity under high-shear conditions, indicating the disruption of the formed flocs under high shear. The destabilization mechanism of the curtain coating differed depending on the type of cobinder. The PVA cobinder flocculates the coating color via a gelling mechanism, while the CMC cobinder flocculates the colors via a depletion flocculation mechanism.
  • Researchpp 7203-7219Reinprecht, L., and Pánek, M. (2015). "Effects of wood roughness, light pigments, and water repellent on the color stability of painted spruce subjected to natural and accelerated weathering," BioRes. 10(4), 7203-7219AbstractPDF
    This study examined the color stability of painted Norway spruce (Picea abies) samples subjected to natural and accelerated weathering, using Duncan’s tests and correlation analyses. The following effects were studied: (1) the different initial roughness of the wood; (2) use of transparent or lightly-pigmented top-coat layers; and (3) the presence of the final water-repellent layer. Natural weathering at a 45° slope in an industrial zone lasted 104 weeks, whereas accelerated weathering in Xenotest with 0.55 W/m2 UV irradiation at 340 nm and sprayed water lasted 12 weeks. The color stability of painted spruce, measured in a CIE-L*a*b* system, was not, in the majority of cases, significantly affected by the initial roughness of the wood, the type of top-coat (WoodCare UV or PerlColor) layer, or presence of the final water repellent (AquaStop) layer. The light pine or larch pigments in the top-coat layers had positive color stabilizing effects. In their presence, the darkening (-DL*) and total color differences (DE*) of the painted samples dropped ca. 2.5 times during exterior weathering and ca. 5 times during Xenotest weathering. Samples painted with transparent coatings turned a reddish shade (+a*) during the Xenotest, while those exposed to the exterior absorbed dirt and became more blue (-b*).
  • Researchpp 7220-7231Wang, X., Shang, Y., Ren, L., Zhang, S., and Guo, P. (2015). "Preparation and surface sizing application of sizing agent based on collagen from leather waste," BioRes. 10(4), 7220-7231AbstractPDF
    Collagen extracted from leather waste was modified with maleic anhydride. Then, using ammonium persulfate as an initiator, by pre-modifying collagen reacted with styrene and ethyl acrylate monomers, a vinyl-grafted collagen sizing agent (VGCSA) for paper was prepared. Before the experiment, the performance of VGCSA was tested and VGCSA emulsion was applied to the surface sizing of the corrugated paper. Effects of the amount of VGCSA, the compound proportion of VGCSA, and starch and styrene-acrylic emulsion were studied relative to paper properties. The morphological changes of the paper before and after sizing were characterized by SEM. It was found that the collagen reacted with styrene and ethyl acrylate monomers. Through the grafting of vinyl and collagen, the crystallinity and thermal stability of VGCSA increased. The structure of VGCSA was spherical with a uniform size, and the average particle size was approximately 350 to 400 nm. After being sized, the surface fibers of paper became smooth and orderly. The optimal sizing of VGCSA was 8 g/m2. The optimal proportion of VGCSA with starch was 4:6, and the optimal proportion of VGCSA with SAE was 2:8. The research indicates that collagen extracted from leather waste could be used as a biomaterial, and environmental and economic benefits could be created as well.
  • Researchpp 7232-7241Sui, L., Zhao, G., and Li, X. (2015). "Pitch control of recycled whitewater from papermaking by Aspergillus oryzae," BioRes. 10(4), 7232-7241AbstractPDF
    Whole cells of Aspergillus oryzae 35 were used as a biocatalyst for the degradation of glycerol trioleate, which largely contributes to pitch deposits in papermaking. Different types of inducers in culture media showed various effects on both the biomass and lipase activity of whole-cell biocatalysts. The cells of A. oryzae 35 cultured with Tween 80 showed higher catalytic activity than the others. The effects of several key factors on A. oryzae 35-catalyzed treatment of a glycerol trioleate-containing whitewater model were investigated, and the optimal pH value, reaction temperature, substrate concentration, and shaking speed were determined to be 7.5, 45 °C, 50%, and 200 rpm, respectively. Results from a practical treatment of whitewater resin sediments with A. oryzae showed that the mean particle size of the original whitewater was sharply reduced from 534 nm to 356 nm after biocatalytic degradation. Aspergillus oryzae whole-cells are newly promising biocatalysts for whitewater treatment in papermaking industries because of their cost-effectiveness, simple preparation, and environmental friendliness.
  • Researchpp 7242-7251Tovar, R. G., Fischer, W. J., Eckhart, R., and Bauer, W. (2015). "White water recirculation method as a means to evaluate the influence of fines on the properties of handsheets," BioRes. 10(4), 7242-7251AbstractPDF
    Fines are an important factor in the papermaking industry with respect to their influence on the mechanical properties of paper. A procedure offering the possibility to produce handsheets with a constant amount of fines, as well as the determination of the fines content, is of great importance in evaluating the influences of different types of fines. In this work, a method based on a white water circulation system and fiber morphology characterization using a flow cell was evaluated. Three different wires for handsheet forming were studied (120-mesh, 325-mesh, and 500-mesh), and the 325-mesh wire was chosen for further trials. Using the 325-mesh wire, a constant amount of fines was achieved after discarding seven handsheets. This method allows reliable evaluation of the effects of primary as well as secondary fines and a cellulosic additive on handsheet properties.
  • Researchpp 7252-7262Güntekin, E., Aydin, T. Y., and Niemz, P. (2015). "Prediction of compression properties in three orthotropic directions for some important Turkish wood species using ultrasound," BioRes. 10(4), 7252-7262AbstractPDF
    Compression properties in three orthotropic directions for some important Turkish wood species, including Calabrian pine (Pinus brutia Ten.), Taurus cedar (Cedrus libani), Oriental beech (Fagus orientalis), and sessile oak (Quercus petraea), were studied using non-destructive and destructive techniques. The materials used in the study consisted of 720 small clear specimens of nominal dimensions of 20 x 20 x 60 mm. The influence of equilibrium moisture content (EMC) was studied over four batches of 15 specimens each, conditioned for six to eight weeks before testing at a temperature of 20 ± 2 °C and at four different relative humidity conditions (50%, 65%, 85%, and 95%). Time of flight values were measured with a commercial ultrasonic tester. Using the time results from the ultrasound device, the wave velocities (length/time) and Edyn values were calculated. Samples were also tested in uniaxial compression to determine the Young’s modulus and compression strength values in three orthotropic directions. The Edyn correlated well with the Young’s modulus and compression strength of the specimens; coefficients of determination ranged between 0.75 and 0.96. Moisture content seems to have more influence than density on sound velocities. Results showed that there is a weak and mostly negative correlation between the density of the specimens and the sound velocity values.
  • Researchpp 7263-7272Wen, L., Han, L., and Zhou, H. (2015). "Factors influencing the charring rate of Chinese wood by using the cone calorimeter," BioRes. 10(4), 7263-7272AbstractPDF
    Wood has better load-bearing capacity following the formation of a char layer when exposed to fire. The charring rate is the most important property of wood with respect to its fire resistance and fire integrity. The objectives of this study were to determine the effects of factors, including density, gas permeability, ring width, grain orientation, and heat flux, on the charring rate. The charring rates of six Chinese woods were tested with a cone calorimeter with densities of 0.35 to 0.69 g/cm3 and moisture contents of approximately 12%. The results indicated that density, gas permeability, and heat flux, but not the grain orientation, significantly affected the charring rate. There was a positive, linear correlation between the heat flux and the charring rate. The density was nearly linearly related to the charring rate for either softwood or hardwood; the correlation was not found for all woods. The positive, linear correlation between the gas permeability and the charring rate was only found along the grain.
  • Researchpp 7273-7291Otto, A., and Parmigiani, J. (2015). "Velocity, depth-of-cut, and physical effects on saw chain cutting," BioRes. 10(4), 7273-7291AbstractPDF
    A better understanding of saw-chain cutting mechanics is needed for more efficient chainsaw designs. The effects of varying key parameters such as workpiece moisture content, workpiece density, cutting velocity, and depth-of-cut, while established for other types of cutting, are largely unexplored and/or unpublished for saw chains. This study contributes to filling this gap through experimentation and analysis. Experiments were conducted using a custom-built saw-chain testing apparatus to measure relevant forces over a range of workpiece moisture contents, workpiece densities, cutting velocities, and depths-of-cut. Analysis consisted of fitting linear regression models to experimental data, identifying trends, and exploring optimum cutting conditions. Results showed that over the range of values included in the study, workpiece moisture content and density had effects that depended on the depth-of-cut. Cutting velocity had a small effect, and depth-of-cut had a large effect. All trends fit well with linear models; however, depth-of-cut required one linear fit for small-to-mid values and a second fit for mid-to-large values. Maximum efficiency was found to occur at a depth-of-cut equal to the transitional value between fits. These results provide basic relationships that can lead to the more effective and efficient use and design of chainsaws.
  • Researchpp 7292-7301Niu, M., Wang, X., Hagman, O., Karlsson, O., and Xie, Y. (2015). "Morphology of burned ultra-low density fiberboards," BioRes. 10(4), 7292-7301AbstractPDF
    The synergistic effect of two fire retardants, a Si-Al compound and chlorinated paraffin, was tested on ultra-low density fiberboards (ULDFs). To further understand the mechanism of fire retardancy, morphologies of unburned and burned ULDFs were studied using a scanning electron microscope with energy dispersive spectroscopy. It was found that as the volume of the burned ULDFs shrank, some crevices appeared. In addition, less fly ash formed on the top of specimens, and more bottom ashes remained in the original framework, with a clear network of structure built by the fibers. Carbon was almost absent in the fly ash; however, the weight ratio of C in the bottom ashes reached the maximum (> 43%) of the composition. Oxygen, Al, and Si appeared to have varying weight ratios for different ashes. Oxygen content increased with increasing Si and Al contents. Furthermore, Cl sharply decreased to less than 1% after combustion. Therefore, upon combustion, it was found that almost all of the substances in ULDFs, except for the Si-Al compound, were pyrolyzed to volatile carbon oxides and Cl compounds, especially the fly ash and lightweight C compounds.
  • Researchpp 7302-7314Pang, A. L., Ismail, H., and Bakar, A. A. (2015). "Effects of kenaf loading on processability and properties of linear low-density polyethylene/poly (vinyl alcohol)/kenaf composites" BioRes. 10(4), 7302-7314AbstractPDF
    This study was conducted to evaluate the possibility of utilizing kenaf (KNF) in LLDPE/PVOH to develop a new thermoplastic composite. The effect of KNF loading on the processability and mechanical, thermal and water absorption properties of linear low-density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites were investigated. Composites with different KNF loadings (0, 10, 20, 30, and 40 phr) were prepared using a Thermo Haake Polydrive internal mixer at a temperature of 150 °C and rotor speed of 50 rpm for 10 min. The results indicate that the stabilization torque, tensile modulus, water uptake, and thermal stability increased, while tensile strength and elongation at break decreased with increasing filler loading. The tensile fractured surfaces observed by scanning electron microscopy (SEM) supported the deterioration in tensile properties of the LLDPE/PVOH/KNF composites with increasing KNF loading.
  • Researchpp 7315-7323Tian, S. Q., Wang, X. W., Zhao, R. Y., and Ma, S. (2015). "Recycling cellulase from enzymatic hydrolyzate of laser-pretreated corn stover by UF membrane," BioRes. 10(4), 7315-7323AbstractPDF
    The ultrafiltration membrane reactor, utilizing a membrane module with a suitable molecular weight alleyway, retains the larger cellulase components. Smaller molecules, such as the fermentable reducing sugars and water, pass through the membrane. The purpose of this work was to investigate the capability of recycling cellulase in the UF membrane. PS30 hollow fiber membrane, an ultrafiltration method using internal pressure, was found to be an ideal membrane separation device, allowing re-use of the enzyme. A Box-Behnken experimental design (BBD) established the following optimum pretreatment parameters: operation pressure at 1.73 bar, temperature at 36.38 °C, and a pH of 5.92. Under these conditions, the model predicted a membrane flux yield of 2.3174 L/(m2•h). The rejection rate of the UF membrane was over 95%.
  • Researchpp 7324-7338Pang, S., H'ng, P., Chai, L., Lee, S., and Paridah, M. T. (2015). "Value added productivity performance of the Peninsular Malaysian wood sawmilling industry," BioRes. 10(4), 7324-7338AbstractPDF
    Value added manufacturing activity in the wood sawmilling industry of Peninsular Malaysia is important for employment opportunities, particularly for low income citizens living in this rural area, to provide returns to the local economy while being environmentally sustainable. This paper is a review on the value added wood sawmill industry in Peninsular Malaysia, using the value of major import and exports of major timbers products and forested area in Peninsular Malaysia over the period 2003 to 2012. The productivity performance measures that are based on the concept of value added are emphasized in this paper. The value added in wood sawmill industry was found to increase from year 2003 to 2012. Consequently, Malaysia is moving on the right path to achieve the goal of National Timber Policy 2020, transforming the timber industry into high value addition industry. However, further analysis using the value added productivity measure found that the value addition rely on international timber price rather than skilled workers.
  • Researchpp 7339-7352Faris, A. H., Mohamad Ibrahim, M. N., Rahim, A. A., Hussin, M. H., and Brosse, N.(2015). "Preparation and characterization of lignin polyols from the residues of oil palm empty fruit bunch," BioRes. 10(4), 7339-7352AbstractPDF
    In this work, lignin polyols were prepared from the liquefaction of kraft lignin and from the direct liquefaction of Elaeis guineensis lignocellulosic waste. The liquefaction reaction was performed with polyhydric alcohols using sulfuric acid as catalyst at 160 °C. The physical and chemical characterizations of lignin and lignin polyols were conducted by elemental analysis, Fourier transform-infrared spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, molecular weight distribution, and thermogravimetric analysis (TGA). Quantitative 13C NMR showed that all aliphatic hydroxyl group values of polyols noticeably increased with the use of the two methods compared to kraft lignin. The average molecular weight analysis of the liquefied product showed that it exhibited high molecular weight compared to kraft lignin. Both structural and thermal characteristics suggest that lignin polyols would be a good substitute for kraft lignin in the synthesis of polymeric compounds such as environmentally friendly resins or wood adhesives, as it presents higher amounts of activated free ring positions, higher molecular weight, and high thermal stability.
  • Researchpp 7353-7360Fileto-Pérez, H. A., Rutiaga-Quiñones, O. M., Sytsa, M. D., Lorne, I. M., Luo, W., Pankow, J. F., and Rutiaga-Quiñones , J. G. (2015). "GC/MS analysis of some extractives from Eichhornia crassipes," BioRes. 10(4), 7353-7360AbstractPDF
    Eichhornia crassipes (water hyacinth) is an invasive weed that causes serious issues for rivers, lakes, and other reservoirs around the world, although it can be an excellent source for bioactive compounds such as phytosterols and some steroids found in many plants. In this study, water hyacinth samples from both Durango and Distrito Federal in Mexico were collected. Ascendant extracts (cyclohexane, hexane, acetone, and methanol) from their leaves, stems, and roots were analyzed. Using boron trifluoride (~10% [~1.3 M] in 1-butanol), all extracts were derivatized. Twenty-four derivatized samples were analyzed using a gas chromatography-mass spectrometry (GC/MS) method. Twenty carboxylic acids were found, as well as squalene, which was found in nine extract samples: four cyclohexane extracts, one hexane extract, three acetone extracts, and two methanol extracts. A compound not reported before, b-stigmasterol, was identified on three hexane extracts, an acetone extract, and a methalonic extract. Spirostane in acetone root extract and cholestane in cyclohexane stem-leaf extract were also identified.
  • Researchpp 7361-7371Zhu, Y., Wang, W., Wang, Y., and Jin, Y. (2015). "Effects of pH and sulfonated lignin on the enzymatic saccharification of acid bisulfite- and green liquor-pretreated poplar wood," BioRes. 10(4), 7361-7371.AbstractPDF
    The effects of pH and sulfonated lignin (SL) on the saccharification of enzymatic hydrolysis were investigated using acid bisulfite (AS)- and green liquor (GL)-pretreated poplar as substrates. The enzymatic sugar conversions of AS- and GL-pretreated poplar could reach high levels at pH 4.8. The sugar conversions of both AS- and GL-pretreated poplar solids increased when hydrophilic SL was used as an additive in the enzymatic hydrolysis. With SL addition, the optimal pH of AS-pretreated poplar moved to 5.1–5.7, while that of GL-pretreated poplar showed no significant difference. The sugar conversions of AS- and GL-pretreated poplar went up and then leveled off with SL charges from 0.05 to 0.3 g/g-substrate. The highest total sugar conversions increased from 76.4% and 86.9% (pH 4.8, without SL) to 83.5% (pH 5.4, SL 0.3 g/g-substrate) and 90.9% (pH 5.0, SL 0.2 g/g-substrate) for AS- and GL-pretreated poplar, respectively.
  • Researchpp 7372-7385Du, Y., Qin, C., Huang, X., Nie, S., and Song, X. (2015). "Enzyme and alkali-aided ECF bleaching of kraft bamboo pulp," BioRes. 10(4), 7272-7385AbstractPDF
    Unbleached kraft bamboo pulp was pretreated by a xylanase and laccase (X/L) treatment, as well as a joint treatment of X/L and alkali, prior to element chlorine free (ECF) bleaching. In comparison with the control test, the joint treatment of X/L and alkali (X/L+0.1%) had more potential to reduce absorbable organic halide (AOX) levels (29.79%) and COD content (21.55%), in addition to improving bleached pulp properties (56.88% decrease in kappa number and 8.94 %ISO increased in brightness). Moreover, the treatment of X/L+0.1% removed more lignin and HexA than X/L treatment. The analysis of XPS indicated that the X/L treatment could noticeably remove the surface lignin of pulp, but the joint treatments of X/L and alkali could promote the production of superficial lignin. FTIR results showed that pretreatments only reduced part of the lignin and carbohydrate contents, but did not change their structures. The joint pretreatment of enzymes and diluted alkali (X/L+0.1%) had more appealing advantages to produce bleached kraft bamboo pulp.
  • Researchpp 7386-7404Khan, G. M. A., Shaikh, H., Alam, M. S., Gafur, M. A., and Al-Zahrani, S. M. (2015). "Effect of chemical treatments on the physical properties of non-woven jute/PLA biocomposites," BioRes. 10(4), 7386-7404AbstractPDF
    Biocomposites based on poly(L-lactic acid) (PLA) and non-woven jute fabrics (NWJF) were fabricated by sandwiching non-woven jute mat between PLA sheets. First, composites were fabricated with various weight proportions of jute fabric (5, 10, 20, and 30 wt.%) with the PLA matrix, and the effect of fabric loading on their mechanical properties was investigated. Higher mechanical properties were found at 10 wt.% fabric-loaded composite. The results show that the tensile, flexural, and impact strengths were increased by 61.7, 52.3, and 47.2%, respectively, as compared with neat PLA. In the second part, the jute fabrics were chemically treated with NaOH, NaClO2, acrylonitrile, acetic anhydride, KMnO4, diphenylmethane diisocyanate, and benzoyl chloride. The effect of chemical treatment on the mechanical and water absorption properties of NWJF/PLA biocomposites was studied. The mechanical properties of these biocomposites were found to be higher than those of untreated biocomposites. Among all the treatments, the combined alkali-benzoylated-treated fabric composite showed higher mechanical properties. The water absorption properties of these composites were found to be remarkably lower than those of untreated fibers. The interfacial adhesion between the fiber and the matrix was shown to increase with surface modification as revealed by SEM analysis.
  • Researchpp 7405-7418Rahman, A., Ching, Y. C., Ching, K. Y., Awanis, N., Chakraborty, A. K., Chuah, C. H., and Liou, N. S. (2015). "Surface modification of natural fiber using Bi2O3/TiO2 composite for photocatalytic self-cleaning," BioRes. 10(4), 7405-7418AbstractPDF
    A photocatalytic fiber was prepared by modifying the surface of jute fiber with a Bi2O3/TiO2 composite. Maleic acid was used as an organic linker, and the coating process was conducted with heat-treatment at 240 °C. At first, the Bi2O3/TiO2 composite was synthesized by incorporating TiO2 nanoparticles onto a Bi2O3 phase. Subsequently, the photocatalytic fiber was prepared by incorporating the Bi2O3/TiO2 composite onto the surface of the fiber. The Bi2O3/TiO2 composite-modified fiber was characterized by field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy. The synthesized composite exhibited notably high photocatalytic activity under visible light irradiation of λ up to 420 nm, whereby it could decompose organic pollutants in the aqueous and gaseous phases. Because of increasing environmental concerns, this photocatalytic system could be an important candidate for decomposing organic pollutants.
  • Researchpp 7419-7433Lestari, A. S. R. D., Hadi, Y. S., Hermawan, D., and Santoso, A. (2015). "Glulam properties of fast-growing species using mahogany tannin adhesive," BioRes. 10(4), 7419-7433AbstractPDF
    Manufacturing glued laminated timber (glulam) can help overcome the limited availability of large-sized timber, and the use of bio-adhesives may resolve environmental problems associated with synthetic adhesives containing high formaldehyde contents. Tannin adhesive is a bio-adhesive that can be used as alternative glue in the manufacture of glulam. The purpose of this study was to determine the physical and mechanical properties of glulam made with mahogany (Swietenia sp.) tannin adhesive and wood from three fast-growing species, namely pine (Pinus merkusii), jabon (Anthocephalus cadamba), and sengon (Falcataria moluccana). Glulam (3 cm × 6 cm × 120 cm in thickness, width, and length, respectively) was manufactured with three layers of lamina. The physical and mechanical properties of the glulams were tested based on relevant standards. The results showed that pine glulam fulfilled the standard for the modulus of rupture and modulus of elasticity, while sengon glulam met the standard for shear strength. In the delamination test, sengon glulam was resistant to immersion in cold water and hot water. All glulams had low formaldehyde emission levels and therefore fulfilled the standard requirements. The results showed that the tannin adhesive from mahogany bark was equal in quality to methylene diphenyl di-isocyanate for glulam manufacturing.
  • Researchpp 7434-7441Fan, H., Wang, S., Liu, J., and Long, J. (2015). "Improving fly ash whiteness and the influence of modified fly ash on the physical strength of paper," BioRes. 10(4), 7434-7441AbstractPDF
    In order to improve the whiteness of fly ash, the particles were coated by in-situ precipitation of calcium carbonate. After different mass ratios of calcium oxide to fly ash were mixed into water, a certain amount of carbon dioxide was bubbled into the mixture to form a precipitated calcium carbonate deposit on the surface of fly ash. With the help of scanning electron microscopy (SEM), the process and the coating mechanism of the unmodified and modified fly ash were studied. The results showed that when a 1:1 mass ratio of calcium oxide to fly ash was implemented, the whiteness of fly ash was increased from 30.3 (the original fly ash) to 74.0 (the modified fly ash). After appropriately controlling for the rate of carbon dioxide, the whiteness was improved to meet the standard for filler in the papermaking industry, and also great advantages in paper physical strength were demonstrated.
  • Researchpp 7442-7454Reyes, P., Pereira, M., and Mendonça, R. T. (2015). "Effect of partial pre-extraction of hemicelluloses on the properties of Pinus radiata chemimechanical pulps," BioRes. 10(4), 7442-7454AbstractPDF
    Extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other bioproducts could provide additional revenue to traditional pulp and paper industries. The effect of hemicelluloses pre-extraction with a hydrothermal (HT) process on Pinus radiata chemimechanical pulp (CMP) properties was investigated in this study. The HT extraction resulted in a release of 7% to 58% of the initial amount of hemicelluloses from the wood. The extraction yield increased with temperature and extraction time. This hemicellulosic fraction was in the form of low molar mass oligomers with molecular weights varying from 1.5 to 100 kDa. Compared with the control (unextracted) CMP pulp, the HT pre-extraction significantly reduced the refining energy to obtain a given fibrillation degree (freeness). The pulp yield with the HT/CMP process was in the range of 56% to 75%. Fiber properties of the pulps from pre-extracted wood, such as fiber length, were reduced, while increases in fiber width, fines content, fiber coarseness, and kink index were observed in comparison with the control pulps. The strength properties of CMP pulps decreased with increasing amounts of hemicellulose removal during the stage prior to pulping.
  • Researchpp 7455-7465Wang, J., Guo, X., Zhong, W., Wang, H., and Cao, P. (2015). "Evaluation of mechanical properties of reinforced poplar laminated veneer lumber," BioRes. 10(4), 7455-7465AbstractPDF
    Three types of reinforcement materials, a carbon fiber-reinforced polymer (CFRP) sheet, a glass fiber-reinforced polymer (GFRP) mesh, and a composite of the CFRP sheet and GFRP mesh, were used to reinforce poplar laminated veneer lumber (LVL), and the multi-step hot-pressing method was also applied. The mechanical properties, i.e., modulus of rupture (MOR), modulus of elasticity (MOE), and horizontal shear strength (HSS), of the reinforced LVL were investigated, as well as the effects of lay-up location of the CFRP sheet/GFRP mesh composite. The results indicated that applying the multi-step hot-pressing method and incorporating the CFRP sheet, GFRP mesh, and the CFRP sheet/GFRP mesh composite noticeably improved the MOR and MOE under horizontal and vertical loadings. Only the multi-step hot-pressing method was able to greatly improve the HSS of reinforced LVL under both loading modes. The improved effect of the three kinds of reinforcing materials on the mechanical properties was ordered as follows: CFRP sheet/GFRP mesh composite > CFRP sheet > GFRP mesh. Locating the CFRP sheet/GFRP mesh composite closer to the surface veneer layer yielded the best mechanical properties for the reinforced poplar LVL.
  • Researchpp 7466-7476Lee, H., Lee, Y. M., Heo, Y. M., Lee, H., Hong, J. H., Jang, S., Min, M., Lee, J., Kim, J. S., Kim, G. H., and Kim, J. J. (2015). "Optimization of endoglucanase production by Trichoderma harzianum KUC1716 and enzymatic hydrolysis of lignocellulosic biomass," BioRes. 10(4), 7466-7476AbstractPDF
    Trichoderma species are widely used for the commercial production of cellulolytic enzymes. In the present investigation, medium components were optimized using a central composite design and response surface methodology to produce endoglucanase (EG) from Trichoderma harzianum KUC1716. From the various medium components tested, cellulose, soy peptone, and thiamine HCl were selected as the optimal carbon, nitrogen, and vitamin sources, respectively. The highest EG (1.97 U/mL) production was obtained with 1.85% cellulose, 0.48% soy peptone, and 0.10% thiamine HCl. EG production in the optimized medium was 2.6 fold higher than in the unoptimized medium. In addition, the crude enzyme preparation from T. harzianum KUC1716 supplemented with β-glucosidase from Schizophyllum commune KUC9397 was used to hydrolyze various types of lignocellulosic materials and showed significant saccharification yields on all lignocellulosic materials, surpassing that of a commercial enzyme cocktail. It was verified that the crude enzyme preparation derived from T. harzianum KUC1716 could replace the commercial enzymes. This highlights the potential of the crude enzymes for use in biomass conversion systems.
  • Researchpp 7477-7488Shang, J., Lin, J., Zhao, G., Zhang, J., Su, Z., and Guo, S. (2015). "Effects of time and chemical curing temperature on the properties of liquefied wood-based precursors and carbon fibers," BioRes. 10(4), 7477-7488AbstractPDF
    Liquefied wood-based precursors and carbon fibers were prepared by various chemical curing processes to investigate the effects of curing time and temperature on the thermostability and tensile strength of carbon fibers. The primary fibers can be converted into high-performance precursors by directly heating at a targeted curing temperature. With the temperature and duration increasing, the number of methylene bonds in the precursors increased, resulting in the enhancement of cross-linkages among molecular chains and the improvement of the thermostability of the precursors. Carbon fibers prepared from the precursors (95 °C and curing time 3 h) exhibited the minimum value in the average interlayer spacing (d002); however, they displayed the highest tensile strength, at almost 800 MPa, which can be classified as fibers of general grade.
  • Researchpp 7489-7500Yang, Q., Huo, D., Shi, J., Lin, L., Liu, Q., Hou, Q., Zhang, H., and Si, C. (2015). "Structural properties of the purified lignins of cornstalk in the cooking process with a solid alkali," BioRes. 10(4), 7489-7500AbstractPDF
    The process of cooking with solid alkali is a novel and efficient technology. In the present work, milled wood lignin (MWL) and water-soluble milled wood lignin (WMWL) were used as the raw materials to research their properties when cooking with MgO and active oxygen. Before and after cooking, the lignin content of the samples was estimated using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), heteronuclear single-quantum coherence-nuclear magnetic resonance (HSQC-NMR), and gel permeation chromatography (GPC). The results showed that the properties of the MWL and WMWL were different. The G unit and A′structure in WMWL were more easily degraded than that in the MWL, where the G unit could be oxidized into a novel G′ unit. The D structure in the MWL with a weak signal could be thoroughly degraded, and the P structure was only present in WMWL and could be generated during the cooking process.
  • Researchpp 7501-7510Li, B., Zhang, Z., Li, W., and Peng, X. (2015). "Effect of yield strength of a circular saw blade on the multi-spot pressure tensioning process," BioRes. 10(4), 7501-7510AbstractPDF
    In this study, a numerical model of the tangential tensioning stress distribution of a circular saw blade tensioned by multi-spot pressure was established using theoretical analysis, and the tangential tensioning stress distribution of the circular saw blade calculated by the model was shown to be true and reliable. The effect of yield strength of the circular saw blade on the distribution of tangential tensioning stress was studied using the numerical model. The research achievements showed that a circular saw blade made with high-strength or ultra-high-strength steel yielded a better tensioning effect during the multi-spot pressure tensioning process, which could promote the application of a circular saw blade made by high-strength or ultra-high-strength steel.
  • Researchpp 7511-7524Shi, J., Xiang, X., Yang, Q., Lin, L., He, J., Chen, X., Mei, X., Guan, J., and Cai, S. (2015). "Active oxygen pretreatment of corn stalk to facilitate biorefining: Structural elucidation of hemicelluloses in yellow liquor," BioRes. 10(4), 7511-7524AbstractPDF
    Biorefining is a potential pathway to cover the shortage of fuels, power, and chemicals from lignocellulosic biomass in the future. However, pretreatment of the biomass is recognized as a technological bottleneck for the cost-effective development of biorefineries, especially for the production of bio-fuels and chemicals. Active oxygen pretreatment is both an eco-friendly and efficient pretreatment process. To elucidate the effect of different chemicals on corn stalk and its hemicellulosic structure, five pretreatment processes were formed with MgO, H2O2, and O2. Additionally, the MgO was also replaced by NaOH and Mg(HO)2. Results show that MgO, which can be completely replaced by Mg(OH)2, is an alkali source and a protective agent in preventing raw material from carbonizing and cellulose from degrading during pretreatment. High pressure oxygen is the main chemical for depolymerizing corn stalk. The removal degrees of lignin and hemicelluloses in the pretreatment processes with oxygen were 81.1 to 87.7% and 73.3 to 83.0%, respectively. Without oxygen, much lower removal degree were achieved (19.3 to 49.0% and 55.5 to 67.6%, respectively). Corn stalk hemicelluloses were composed of (1→4)-β-D-xylopyranose substituted with α-L-arabinofuranosyl residues and 4-O-methyl-α-D-glucuronic acid units. The molecular weight of hemicelluloses decreased from 22,000 g/mol to the range 3100 to 6400 g/mol.
  • Researchpp 7525-7543Dinulică, F., Albu, C. T., Borz, S. A., Vasilescu, M. M., and Petritan, I. C. (2015). "Specific structural indexes for resonance Norway spruce wood used for violin manufacturing," BioRes. 10(4), 7525-7543AbstractPDF
    The aim of this study was to assess wood quality using diagnostic keys related to the main traits of trunk architecture in the most important resource of resonance spruce of the Romanian Carpathians. The material sampled from standing and felled trees yielded 568 individual ring series adding up to over 81,000 growth rings. The resonance xylotype was first recognized in felled trees, already designated for violin manufacture, for which a 6-class quality classification system was proposed. This system was extended to the qualitative classification of the standing trees (diameter at breast height larger than 10 cm). The width and regularity of the growth rings, the width of the sapwood and latewood, and the compression wood ratio are the variables that make recognition of trees containing resonance wood possible. Wood with resonance structural value was detected locally along the tree stem, and the best resonance structural quality was found uniformly distributed from 5 to 9 m above the ground and in the external half of the cross-section. Trees having a proper structure for violin fliches, but not yet with an appropriate size (38 cm underbark diameter), accounted for about 7% of the total tree population.
  • Researchpp 7544-7554Salmén, L., Bergnor, E., Olsson, A. M., Åkerström, M., and Uhlin, A. (2015). "Extrusion of softwood kraft lignins as precursors for carbon fibers," BioRes. 10(4), 7544-7554AbstractPDF
    There is much interest in using less expensive raw materials as precursors for carbon fibre manufacture to increase the utilisation of strong, light-weight composite materials in the transportation sector. One such potential raw material is lignin. Most studies exploring melt spinning of lignin have used lignins from organosolv or hardwood kraft delignification processes. There has been little success reported in utilisation of the more commercially available softwood kraft lignins. In this study, lignins from different softwood kraft cooking processes were investigated with respect to their melt spinning performance and conversion to carbon fibres. The isolated lignins differed mainly in molecular weight, glass transition temperature, and softening temperature. All of the lignins produced from the laboratory cooks could be extruded without any plasticizer addition. However, the lignins contained volatiles that resulted in bubbles being formed along the length of the fibres. After vacuum drying, at elevated temperatures to remove volatiles, only the lignin originating from conventional kraft cooking was able to be melt extruded without plasticiser addition; this lignin had the lowest molecular weight amongst the samples. The stabilisation and carbonisation of these fibres gave carbon fibres with strengths comparable to those produced from lignins of other origins.
  • Researchpp 7555-7568Zhang, F., Wu, W., Sharma, S., Tong, G., and Deng, Y. (2015). "Synthesis of cyclodextrin-functionalized cellulose nanofibril aerogel as a highly effective absorbent phenol pollutant removal," BioRes. 10(4), 7555-7568AbstractPDF
    Cellulose nanofibril (CNF) aerogels with grafted beta-cyclodextrin (β-CD) were prepared for the adsorption of phenol pollutants from water. Compared with regular wood fibers, CNF aerogel not only can immobilize more β-CDs, but also it provides higher porosity and a larger specific surface area for phenol absorption. The CNF-CD aerogel becomes mechanically robust through chemical crosslinking. It can be easily separated from water after adsorbing phenol pollutants without complicated centrifugation or filtration. A series of studies on phenol adsorption was conducted. The results indicated that the CNF-CD aerogel prepared with a suspension concentration of 3% (w/w) had the highest adsorption capability. In addition, the CNF-CD aerogel showed an excellent reusability. The results indicated that the CNF-CD aerogel is an environmentally friendly and promising adsorbent for removing phenol pollutants from water.
  • Researchpp 7569-7579Feng, H., Fang, Y., Li, J., and Li, G. (2015). "Detecting longitudinal position of internal log hole using an impact-echo method," BioRes. 10(4), 7569-7579AbstractPDF
    This paper presents a new methodology for detecting the longitudinal location of the hidden hole in a log using impact-echo testing. The hole and the end surface of the log produced two different amplitude peaks in the frequency spectrum after a mechanical tap on the top of the log. The ratio of the two frequencies was used to estimate the longitudinal position of the hole. The major advantage of this method is that it avoids measuring the travel velocity of the stress wave, which is sensitive to many factors and then poses a formidable challenge to the realization of inspection. Experimental studies were carried out using Pine logs with mechanically drilled holes and a Cinnamomum camphora log with natural hole. The results indicated that the estimated positions were in good agreement with the actual position of the hole. The impact-echo testing can be applied to detect the longitudinal position of the internal hole in log.
  • Researchpp 7580-7590Qin, S., Wang, Y., Xing, Y., Zhao, P., Bu, L., Sun, D., and Jiang, J. (2015). "Comparison of enzymatic hydrolysis of bamboo using steam explosion and acid sulfite, alkali, and alkaline sulfite pretreatments," BioRes. 10(4), 7580-7590AbstractPDF
    A combination of steam explosion (SE) and chemical pretreatments, such as acid sulfite (AS), alkali (AL), and alkaline sulfite (ALS), were evaluated using bamboo. Low pressure steam explosion at 1.25 MPa for 4 min was first applied to the bamboo. Then, the pretreated bamboo was delignified using three chemical pretreatments. Enzymatic hydrolysis was also compared among the pretreated bamboo samples. It was found that SE-ALS could be a potential method for bamboo pretreatment, which led to the reduction of lignin from 25.15% to 1.74% at 165 °C for 2 h in 5% (w/v) Na2SO3 and 0.7% (w/v) NaOH; however, little cellulose was solubilized during ALS pretreatment. A maximum glucose yield of 99.35% was achieved during the enzymatic hydrolysis process when combined with the SE-ALS pretreatment. The SE-ALS method resulted in a lower degree of lignin condensation and increased delignification compared to the SE-AS method. In addition, the SE-ALS pretreatment protected carbohydrates from degradation better than the SE-AL methods.
  • Researchpp 7591-7603Wan Sharifudin, W. S. S. A., Sulaiman, A., Mokhtar, N., Samsu Baharuddin, A., Tabatabaei, M., Busu, Z., and Subbian, K. (2015). "Presence of residual oil in relation to solid particle distribution in palm oil mill effluent," BioRes. 10(4), 7591-7603AbstractPDF
    The production of palm oil requires a large amount of water, which subsequently turns into wastewater known as palm oil mill effluent (POME). Because of its high organic content, there has been debate over how to utilize POME for oil recovery. POME is usually mainly comprised of water (95 to 96%), total solids (4 to 5%), suspended solids (2 to 4%), and oil (0.6 to 0.7%). The lignocellulosic particles in POME are highly oleophilic and capable of absorbing oil. Therefore, the objective of this study was to understand the presence of residual oil and try to relate with the oil loss in POME and to identify the solid particles in POME and their correlations. Microscopic observations showed that most of the oil droplets available in POME were less than 100 µm in size. If given the opportunity to settle, the highest quantity of oil droplets and solid particles was in the bottom layer, followed by the middle layer, and lastly the upper layer. In cases where the contact angle of water was less than 45° on POME solids, the absorption rate was 0.11 ± 0.03 µL/s and 0.09 ± 0.01 µL/s, respectively. This study concluded that the oil losses in POME were partly due to the absorption of oil by the fibers.
  • Researchpp 7604-7617Bergier, I., Maia, C. M. B. F., Guiotoku, M., Paiva, P., Silva, A. P., and Novotny, E. H. (2015). "Pyrolysis dynamics of biomass residues in hot-stage," BioRes. 10(4), 7604-7617.AbstractPDF
    Original data for mass, element, and methane dynamics under controlled pyrolysis are presented for several biomass feedstocks. The experimental system consisted of an environmental (low-vacuum) scanning electron microscopy (ESEM) with a hot-stage and energy-dispersive X-ray spectroscopy (EDS) detector. A tunable diode laser (TDL) was coupled to the ESEM vacuum pump to measure the methane partial pressure in the exhaust gases. Thermogravimetric analysis and differential thermal analysis (TG/DTA) in a N2 atmosphere was also carried out to assess the thermal properties of each biomass. It was found that biochars were depleted or enriched in specific elements, with distinct methane formation change. Results depended on the nature of the biomass, in particular the relative proportion of lignocellulosic materials, complex organic compounds, and ash. As final temperature was increased, N generally decreased by 30 to 100%, C increased by 20 to 50% for biomass rich in lignocellulose, and P, Mg, and Ca increased for ash-rich biomass. Methane formation also allows discriminating structural composition, providing fingerprints of each biomass. Biomass with low ashes and high lignin contents peaks CH4 production at 330 and 460 °C, whereas those biomasses with high ashes and low lignin peaks CH4 production at 330 and/or 400 °C.
  • Researchpp 7618-7626Gaff, M., Kvietková, M., Gašparík, M., Kaplan, L., and Barcík, S. (2015). "Effect of selected parameters on the surface waviness in plane milling of thermally modified birch wood," BioRes. 10(4), 7618-7626AbstractPDF
    This article focuses on the plane milling of thermally modified birch wood while taking into account technological parameters that have substantial effects on the processed wood surface’s average waviness profile deviation (Wa). The milling process was affected by the cutting speed, which varied from 20 to 60 m/s, with a feed rate of 4, 8, and 11 m/min. The results obtained on the set of thermally modified test specimens, were compared with the results obtained on test specimens without heat treatment. The surface finish was measured using various milling parameters. The material removal was 1 mm per pass. The results indicate that the thermal processing of wood did not significantly influence the arithmetic average deviation of the roughness profile (Ra). Cutting speed and feed rate had the most significant effects among the monitored factors. The lowest arithmetic average deviation of the roughness profile (Ra) was determined at a feed rate of 4 m/min and cutting speed of 40 m/s. An increase in cutting speed led to a decrease in the average roughness, while increased feed rate had the opposite effect.
  • Researchpp 7627-7639Yahya, M., Lee, H. V., and Abd Hamid, S. B. (2015). "Preparation of nanocellulose via transition metal salt-catalyzed hydrolysis pathway," BioRes. 10(4), 7627-7639AbstractPDF
    Nanocellulose was successfully prepared from microcrystalline cellulose (MCC) via nickel salt-catalyzed hydrolysis under mild reaction conditions of 45 °C for 15 min. The mild acid nickel salt-catalyzed hydrolysis was able to selectively depolymerize the amorphous regions of cellulose and retain its crystalline region, thus improving the crystallinity of the treated product at the nanoscale up to 80%. FTIR analysis confirmed that the basic cellulose structure of inorganic metal salt-treated products was maintained and that no derivative was formed. Furthermore, the synthesized Ni-treated nanocellulose (NTC) products appeared in the form of cluster fragments with spider-web-like appearance (fiber diameter of 10 to 60 nm and fiber length of 300 to 600 nm), thus providing aspect ratios in the range of 7.96 to 9.11. In addition, NTC products exhibited relatively higher thermal stability as compared to MCC because of the presence of high crystallinity phases and the absence of impurities (such as nitrate ions) on the nanocellulose surface. Thus, the present study concluded that nickel-based inorganic salt is an efficient and selective catalyst for the hydrolysis of MCC with high simplicity in operation and short preparation time.
  • Researchpp 7640-7652Shenga, P. A., Bomark, P., Broman, O., and Sandberg, D. (2015). "Simulation of tropical hardwood processing - sawing methods, log positioning, and outer shape," BioRes. 10(4), 7640-7652.AbstractPDF
    To increase understanding of breakdown strategies for Mozambican timber, simulations were carried out using different sawing patterns that can be alternatives to the low degree of refinement performed for export today. For the simulations, 3D models of 10 Jambirre and 5 Umbila logs were used. The log shape was described as a point cloud and was acquired by 3D-laser scanning of real logs. Three sawing patterns (cant-sawing, through-and-through sawing, and square-sawing) were studied in combination with the log positioning variables skew and rotation. The results showed that both positioning and choice of sawing pattern had a great influence on the volume yield. The results also showed that the log grade had an impact on the sawing pattern that should be used for a high volume yield. The volume yield could be increased by 3 percentage points by choosing alternative sawing patterns for fairly straight logs and by 6 percentage points for crooked logs, compared to the worst choice of sawing pattern.
  • Researchpp 7653-7666Wang, S. M., Shi, J. Y., and Xu, W. (2015). "Synthesis and characterization of starch based aqueous polymer isocyanate wood adhesive," BioRes. 10(4), 7653-7666AbstractPDF
    Modified starch was prepared in this work by acid-thinning and oxidizing corn starch with ammonium persulfate. Also, starch-based aqueous polymer isocyanate (API) wood adhesive was prepared. The effect of the added amount of modified starch, styrene butadiene rubber (SBR), polymeric diphenylmethane diisocyanate (P-MDI), and the mass concentration of polyvinyl alcohol (PVOH) on the bonding strength of starch-based API adhesives were determined by orthogonal testing. The starch-based API adhesive performance was found to be the best when the addition of modified starch (mass concentration 35%) was 45 g, the amount of SBR was 3%, the PVOH mass concentration was 10%, and the amount of P-MDI was 18%. The compression shearing of glulam produced by starch-based API adhesive reached bonding performance indicators of I type adhesive. A scanning electron microscope (SEM) was used to analyze the changes in micro-morphology of the starch surface during each stage. Fourier transform infrared spectroscopy (FT-IR) was used to study the changes in absorption peaks and functional groups from starch to starch-based API adhesives. The results showed that during starch-based API adhesive synthesis, corn starch surface was differently changed and it gradually reacted with other materials.
  • Researchpp 7667-7680Tang, C., Zhang, D., and Lu, X. (2015). "Improving the yield and quality of tar during co-pyrolysis of coal and cotton stalk," BioRes. 10(4), 7667-7680.AbstractPDF
    Co-pyrolysis of Shenmu coal (SM) and cotton stalk (CS) at different blend ratios were carried out in a tubular furnace. The pyrolysis temperature was up to 600 °C at 5 °C/min and kept for 15 min. The results indicated that there was an interactive effect between SM and CS, which increased the tar yield. Moreover, the content of light components in co-pyrolysis tar from all CS/SM blend ratios was higher than that in the tar derived from SM pyrolysis. This interaction not only increased tar yields but also upgraded the quality of tar in the co-pyrolysis process. Compared with the co-pyrolysis of de-ashed CS and SM, the inherent minerals of CS had great effects on the co-pyrolysis tar yield. The analysis results of n-hexane soluble extracted from co-pyrolysis tar by gas chromatography/mass spectrometry indicated that the organic matters of CS had a significant effect on the alkene formation of tar during co-pyrolysis. The maximal tar yield was 13.73 wt% (daf) and the yield of n-hexane soluble reached 11.13 wt% (daf) under optimum conditions.
  • Researchpp 7681-7692Geng, A., Wu, J., Xie, R., Li, X., Chang, F., and Sun, J. (2015). "Construction of a bacterial cellulase cocktail for saccharification of regenerated cellulose and pretreated corn stover," BioRes. 10(4), 7681-7692AbstractPDF
    To apply bacterial cellulases for efficient saccharification of biomass, three Clostridium thermocellum cellulases and a Thermoanaerobacter brockii β-1,4-glucosidase were synthesized in Escherichia coli, and the proportions among them were optimized. When the activities of CelD, CBHA, CBH48Y, and CglT were set at 554, 0.91, 0.91, and 856 mU per assay, respectively, the percent conversion of regenerated cellulose (0.92 g/L) reached 80.9% within 24 h at 60 °C without shaking. Meanwhile, the percent conversion of pretreated corn stover (0.62 g/L) reached 70.1%. Gradually raising the loads of regenerated cellulose from 0.92 to 4.58 g/L resulted in a linear increase in glucose production from 870 to 3208 μg (R2=0.997), as well as a decrease in the percent conversion from 80.9% to 59.6%. These findings suggested that the cellulase cocktail is efficient in saccharification of regenerated cellulose, as well as pretreated corn stover, and has potential applications in the biofuels industry.
  • Researchpp 7693-7703Wang, B., Zhang, H. R., Huang, C., Chen, X. F., Shi, S. L., Xiong, L., Luo, J., and Chen, X. D. (2015). "Polyvinyl chloride/attapulgite/micro-crystalline cellulose (MCC) composites preparation and analysis of the role of MCC as a compatibilizer," BioRes. 10(4), 7693-7703AbstractPDF
    To improve the performance of polyvinyl chloride (PVC), composites incorporating polyvinyl chloride (PVC), attapulgite nanoparticles (ANPs), and microcrystalline cellulose (MCC) were successfully prepared. The composites had higher vicat softening temperatures (VSTs) and the MCC had a great influence on mechanical properties of the composites. When MCC was added from 0 to 5 per hundred parts of PVC (phr), the mechanical properties of the composites increased, but the mechanical properties of the composites decreased when the MCC was more than 5 phr. The tensile breaking stress, tensile strength, and impact strength were maximized with increases of 19.76 N (4.1%), 29.66 MPa (15.5%), and 13.8 MPa (7%) when 5 phr MCC was added. Infrared spectral analysis indicated that MCC and ANPs were present in the composites. Scanning electron microscopy showed that the composites system was distributed into two phases, which indicated that MCC in composites was dissolved in the PVC matrix, and some of MCC coated the surface of ANPs as a compatibilizer. Overall, this study provided a promising method for PVC modification to improve its performance.
  • Researchpp 7704-7714Xu, Y., Zhang, W., Yue, X., and Zhang, D. (2015). "Silica removal using aluminium sulphate and sodium aluminate during the bamboo cooking process," BioRes. 10(4), 7704-7714AbstractPDF
    The desilication effects of aluminium sulphate and sodium aluminate on kraft bamboo pulp during the cooking process were investigated in this study. Furthermore, the residual aluminium ion concentration in the resulting black liquor was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) to evaluate the scaling properties of black liquor during the evaporation process. Atomic force microscopy (AFM) and scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDS) analysis showed that aluminium salts could react with silica to form a silica-alumina compound, which can adhere to the fibre surface during the cooking process. As a result, the silicon content in the black liquor could be effectively decreased by the addition of aluminium sulphate and sodium aluminate. A silica removal ratio of 74% could be achieved when the loadings of aluminium sulphate and sodium aluminate were 2.0 wt.% and 1.5 wt.%, respectively. Finally, the concentration of aluminium ions was 7.31 ppm under optimised conditions. Based on these considerations, any amounts of aluminum ion passing into the black liquor are unlikely to contribute to scaling problems.
  • Researchpp 7715-7724Salem, M. Z. M., Nasser, R. A., Zeidler, A., Elansary, H. O., Aref, I. M., Böhm, M., Ali, H. M., and Ahmed, A. I. (2015). "Methylated fatty acids from heartwood and bark of Pinus sylvestris, Abies alba, Picea abies, and Larix decidua: Effect of strong acid treatment," BioRes. 10(4), 7715-7724AbstractPDF
    Methylated fatty acid (FA) compounds in the heartwood and bark of some softwood species, specifically Pinus sylvestris, Abies alba, Picea abies, and Larix decidua, grown in the Czech Republic were evaluated. Strong H2SO4 was used for methylation of the lipids. The highest content of lipid was found in P. abies bark (40.132 mg/g o.d. sample), and the lowest content was in A. alba wood (11.027 mg/g o.d. sample). The highest concentration of FAs was observed in L. decidua bark. The highest percentages of FAs in wood of P. sylvestris were arachidic acid and oleic acid. In bark, the highest percentages of FAs were stearic acid, palmitic acid, and oleic acid. The FAs with the highest concentrations in A. alba wood were arachidic acid, palmitic acid, pentadecanoic acid, and margarinic, and those in bark were behenic acid, lignoceric acid, and arachidic acid. P. abies wood FAs showed arachidic acid, palmitic acid, and margarinic acid, and the bark contained lignoceric acid and arachidic acid. The FAs of L. decidua wood were arachidic acid, palmitic acid, and stearic acid, and in bark they were pentacosylic acid, docosahexaenoic acid (DHA), lignoceric acid, arachidic acid, and behenic acid. The lack of typically dominant unsaturated fatty acids (e.g. 18:1, 18:2), compared to literature values were attributed to the application of strong acid for the hydrolysis.
  • Researchpp 7725-7737Salem, M. Z. M., Zeidler, A., Böhm, M., Mohamed, M. E. A., and Ali, H. M. (2015). "GC/MS analysis of oil extractives from wood and bark of Pinus sylvestris, Abies alba, Picea abies, and Larix decidua," BioRes. 10(4), 7725-7737AbstractPDF
    Wood and bark oil extractives components (OECs) of Pinus sylvestris, Abies alba, Picea abies, and Larix decidua grown in the Czech Republic were analyzed using gas chromatography/ mass spectrometry (GC/MS). The analysis showed the presence of monoterpene, sesquiterpene, diterpenoids, and resin acids. The highest percentages of OECs in the wood of P. sylvestris were α-fenchyl alcohol (26.04%), D-fenchyl alcohol (12.39%), and L-borneol (8.81%); the OECs in the bark included α-methyl-γ-butyrolactone (31.88%) and isodecyl octyl phthalate (15.85%). The most frequently occurring OEC in A. alba wood were 4-hydroxy-4-methyl-2-pentanone (73.36%), α-cedrol (10.08%), and 2,6-dimethyl-1,3,6-heptatriene (7.35%); the most OECs in the bark were di(2-ethylhexyl)phthalate (59.83%), methyl cyclopentane (16.63%), and 13-epimanool (6.31%). P. abies wood OECs included 4-hydroxy-4-methyl-2-pentanone (29.42%), α-cedrol (26.98%), ∆3-carene (6.08%), and terpinen-4-ol (5.42%); the most OECs in the bark were di(2-ethylhexyl)phthalate (30.91%), cyclohexane (12.89%), caryophyllene oxide (8.90%), and α-pinene (4.59%). OECs of L. decidua wood were α-terpineol (26.06%), isoborneol (14.12%), camphene (11.78%), D-fenchyl alcohol (10.39%), and larixol (4.85%); OECs in the bark were larixol (33.29%), phthalic acid mono-2-ethylhexyl ester (16.96%), 13-epimanool (15.40%), and cyclohexane (8.44%).
  • Researchpp 7738-7751Zeng, C., Zheng, H., Lv, J., Chen, X., and Huang, B. (2015). "Liquefaction of fir saw dust in supercritical ethanol with dissolved phosphotungstic acid," BioRes. 10(4), 7738-7751AbstractPDF
    An environmentally benign approach is put forward with the focus on directly liquefying and depolymerizing Cunninghamia lanceolata (Lamb.)Hook. (Chinese fir) sawdust into ethyl levulinate (EL) under supercritical ethanol (scEtOH) conditions by using phosphotungstic acid (PTA) as a catalyst. The effects of parameters such as catalyst dosage, temperature, and reaction time on alcoholysis yield were investigated. The experimental results show that the biomass alcoholysis yield reached 95.35% with 0.5 g PTA as a catalyst at 260 °C for 30 min. Alcoholysis yield and quantitative content of EL depended on the catalyst. The light bio-oil was primarily composed of phenols, aldehydes, ketones, and esters. A high quantitative content of EL up to 20.82% (AR, Relative abundance) was achieved, compared to 0.73% AR when PTA was not added. Hence, scEtOH with dissolved PTA may offer novel media for both chemical reactions and biomass conversion technology as a replacement for environmentally undesirable organic solvents.
  • Researchpp 7752-7762Seo, J. H., Kim, H. J., and Ahn, C. D. (2015). "Effect of two-step thermal treatments on peroxide bleachability of thermomechanical pulp," BioRes. 10(4), 7752-7762AbstractPDF
    In hydrogen peroxide bleaching of thermomechanical pulp (TMP), reaction temperature and time are the main factors that can improve the bleachability of pulp fibers. However, high temperatures can induce some problems such as cellulose degradation, yield loss, low fiber strength, and high environmental load. These negative effects of high temperature are mainly caused by radicals formed from the decomposition of hydrogen peroxide. To avoid the adverse effects of high temperature, we used two-step thermal treatments during hydrogen peroxide bleaching of TMP. The temperatures used in the two-step thermal treatments were 80 and 45 ˚C for a total bleaching time of 1 hour. In H2O2 bleaching of TMP, two-step thermal treatments were found to have had positive effects on the optical and physical properties of the pulp. The ISO brightness of the pulp bleached by two-step thermal treatments with hydrogen peroxide was identical to that of pulp bleached by conventional hydrogen peroxide bleaching. The post color number (PC number) of TMP was sharply increased after bleaching at 80 ˚C for 40 minutes. The post color number of TMP bleached by two-step thermal treatments is lower than that of TMP bleached by a one-step thermal treatment. The zero-span tensile index was also improved by two-step thermal treatments.
  • Researchpp 7763-7771Vainio-Kaila, T., Kyyhkynen, A., Rautkari, L., and Siitonen, S. (2015). "Antibacterial effects of extracts of Pinus sylvestris and Picea abies against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Streptococcus pneumoniae," BioRes. 10(4), 7763-7771AbstractPDF
    Pine heartwood, sapwood, and spruce extracts were tested against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis (VRE), Escherichia coli O157:H7, and Streptococcus pneumoniae. The bacterial strains were cultured in a broth with and without the wood extracts. Also, the antibacterial effect of the extracts was studied by performing the antimicrobial sensitivity test method on agar plates. Both pine extracts had a clear antibacterial effect on MRSA, VRE, and S. pneumoniae. Only pine sapwood extract had an effect on E. coli and it was weaker than on other strains. Spruce showed a clear antibacterial effect on S. pneumoniae and a weaker effect on MRSA and VRE. The results suggest that these wood species have potential as surface materials in hospital and day care environments.
  • Researchpp 7772-7781Sofuoglu, S. D. (2015). "Determination of optimal machining parameters of massive wooden edge-glued panels made of European larch (Larix decidua Mill.) using Taguchi design method," BioRes. 10(4), 7772-7781.AbstractPDF
    In this paper, the optimization of computer numerical control (CNC) machining parameters were conducted using the Taguchi design method on the surface quality of massive wooden edge glued panels (EGP) made of European larch (Larix decidua Mill). Three machining parameters and their effects on surface roughness were evaluated. These parameters included tool clearance strategy, spindle speed, and feed rate. An analysis of variance (ANOVA) was performed to identify the significant factors affecting the surface roughness (Ra and Rz). Optimum machining parameter combinations were acquired by conducting an analysis of the signal-to-noise (S/N) ratio. Optimal cutting performance for the Ra and Rz was obtained for the cutter at a tool clearance strategy of an offset 16000 rpm spindle speed and 1000 mm/min feed rate. The surface roughness, both the Ra and Rz, increased with increasing feed rate. Optimal cutting performance for Ra and Rz was obtained for a tool clearance strategy of an offset 16000 rpm spindle speed, and 1000 mm/min feed rate cutting settings. Based on the confirmation tests, Ra decreased 2.2 times and Rz 1.8 times compared to the starting cutting parameters.
  • Researchpp 7782-7794Li, G., Fu, Y., Shao, Z., Zhang, F., and Qin, M. (2015). "Preparing cationic cellulose derivative in NaOH/urea aqueous solution and its performance as filler modifier," BioRes. 10(4), 7782-7794AbstractPDF
    Cellulose etherification with 3-chloro-2-hydroxypropyl-trimethylammonium chloride (CHPTAC) was carried out in NaOH/urea aqueous solution, under homogeneous conditions. The substitution degree of the prepared quaternized cellulose, cellulose-CHPTAC, increased with increasing molar ratio of CHPTAC/anhydroglucose unit (AGU), reaction temperature, and reaction time. The structure of the cellulose-CHPTAC was characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H- and 13C-NMR), and thermal gravimetric analysis (TGA). Moreover, a cellulose-CHPTAC sample (DS=0.52) was used to modify ground calcium carbonate (GCC) fillers by the surface wrapping method. The results showed that the filler retention was improved by surface modification of GCC fillers using cellulose-CHPTAC, and the negative impact of filler addition on paper strength was reduced. The quaternized cellulose prepared in NaOH/urea aqueous solution could be considered a new, promising filler modifier.
  • Researchpp 7795-7807Zhou, B., Zhou, J., Zhang, Q., Chen, D., Liu, X., Wang, L., Ji, R., and Ma, H. (2015). "Properties and combustion characteristics of molded solid fuel particles prepared by pyrolytic gasification or sawdust carbonized carbon," BioRes. 10(4), 7795-7807AbstractPDF
    Pyrolytic gasified charcoal (PGC) and tar are the solid and liquid products, respectively, yielded from biomass gasification technology. In this paper, PGC was molded with adhesives to prepare molded solid fuel (MSF). Tar and PGC were obtained from the pyrolytic gasification of wood chips and sawdust from pine and cedarwood. PGC was molded with phenol resin prepared by wood tar to prepare MSF (MSF-MP). Meanwhile, there were two other methods used to prepare MSF. PGC molded with common phenol resin was one method (MSF-P). PGC was molded with starch adhesive to prepare MSF-S. Wood powder carbonized carbon (WPCC) obtained from the marketplace was employed as a trial sample. The properties and combustion characteristics of MSFs and WPCC were studied. It was found that the shatter strength of these MSFs were more than 95%. MSFs had higher activation energy and comprehensive combustion index compared to WPCC. MSF-MP yielded the following data: shatter strength: 95.86%, lower heating value (LHV): 25.89 MJ∙kg-1, ignition: 325 °C, comprehensive combustion index: 1.73×10-10, and activation energy: 61.38 kJ∙mol-1. The LHV and activation energy of MSF-MP were superior to those of other MSFs. Therefore, MSF-MP has a market potential for use as barbecue charcoal in restaurant or family gatherings. The preparation of MSF-MP is a prospective method for the utilization of PGC and wood tar.
  • Researchpp 7808-7816Gominho, J., Lourenço, A., Neiva, D., Fernandes, L., Amaral, M. E., Duarte, A. P., Simões, R., and Pereira, H. (2015). "Variation of wood pulping and bleached pulp properties along the stem in mature Eucalyptus globulus trees," BioRes. 10(4), 7808-7816AbstractPDF
    The wood of a mature (40-year-old) Eucalyptus globulus Labill tree was characterized at different stem height levels (0%, 10%, 35%, and 50% of total height) regarding pulping, bleaching, and paper properties. Pulp yields increased upwards from 46% to 50%, and Kappa number decreased from 17.5 to 12.3 at 0 and 50% height, respectively. The estimated specific wood consumption ranged from 3.2 m3 odt-1 to 3.1 m3 odt-1 at 0% and 50% height levels, respectively. Pulp drainage varied along the stem, with less drainability (20.3 ºSR) and higher water retention value (1.07 g.g-1) at the base. Pulp fiber length increased (827 µm vs. 877 µm) and width decreased (19 µm vs. 17 µm) from 0% to 50% height levels. Tensile, tear, and internal bond strength decreased upwards, with mean values of 34.9 N.m.g-1, 3.1 mN.m2.g-1, and 95.8 J.m-2, respectively. These findings support the use of mature E. globulus trees without loss of pulp production and quality.
  • Researchpp 7817-7833Hong, H., Liu, H., Zhang, H., He, H., Liu, T., and Jia, D. (2015). "Blossom morphology and correlative performance improvement of recycled polyethylene/wood flour composites with steam-activated interfaces," BioRes. 10(4), 7817-7833AbstractPDF
    Interfacial compatibility plays a key role in the performances of natural fiber-reinforced composites. The measures commonly used to improve the interfacial compatibility focus more on the addition of various compatibilizers than on the structural modification of the natural fiber. In this paper, an attempt was made to enlarge the interfacial interaction areas of the recycled polyethylene (rPE)/wood flour (WF) composites by steaming the WF. Multi-monomer graft copolymers of polyethylene (GPE) were used as compatibilizers for the composites. How the enlarged interfaces affected the morphology, mechanical properties, water resistance, thermal stability, and dynamic rheological properties of the rPE/WF composites was investigated. The steaming process was able to enlarge the voids of the WF and therefore activate more interfaces for interactions. It was found that the interfacial morphology of the composites was affected by the degree of interfacial compatibility of the composites and so was characterized by various distinctive blossom shapes having a variation of compositions. With the help of GPE, the steaming process was able to significantly improve the interfacial compatibility of the composites and therefore improve the mechanical properties, water resistance, thermal stability, and dynamic rheological properties of the composites.
  • Researchpp 7834-7853Tozluoğlu, A., Özyürek, Ö., Çöpür, Y., and Özdemir, H. (2015). "Integrated production of biofilm, bioethanol, and papermaking pulp from wheat straw," BioRes. 10(4), 7834-7853AbstractPDF
    Depending on the production method, traditional paper mills often utilize the black liquor by burning it for energy. Hemicelluloses extracted from the raw material prior to pulping could be utilized to produce biochemical fuels. The aim of this study was to pre-extract hemicelluloses from wheat straw by treating the biomass with hot water and alkali (NaOH or the combination NaOH+NaBH4) at varying temperatures and chemical concentrations, and also to integrate resulting solid material to produce pulp and to produce bioethanol and biodegradable films from extracted liquor consisting mostly of xylan. Optimum hot water (135 °C) and alkali pre-extractions (16.7% NaOH at 50 °C) removed 16.5% and 33.6% of the xylan from the straw structure, respectively. The liquid portion of the hot water (135 °C) and alkali (16.7% NaOH at 50 °C) pre-extracted oven-dry (OD) straw yielded up to 7.79% and 6.81% (g/100 g soluble material) ethanol. Good-quality biodegradable films were produced when some gluten and nanocellulose was added to the extracted xylan. Although the hot water pre-extracted pulp yield was slightly lower, its physical and mechanical pulp properties were comparable to those of the corresponding conventional soda pulp.
  • Researchpp 7854-7864Dong, X., Sun, T., Liu, Y., Li, C., and Li, Y. (2015). "Structure and properties of polymer-impregnated wood prepared by in-situ polymerization of reactive monomers," BioRes. 10(4), 7854-7864AbstractPDF
    This study demonstrates the preparation, structure, and properties of polymer-impregnated wood (PIW) based on novel Muchelia macclurei wood through the in-situ polymerization of vinyl and functional monomers. Mixed monomers of glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EGDMA) (2:1 molar ratio) were effectively vacuum/pressure impregnated into the cellular structure of the fast-growing wood, and then they underwent a catalytic-thermal polymerization process to form a polymer-impregnated wood composite. Scanning electron microscope (SEM) observations showed that the polymer formed from the monomers occupying the cell lumens and formed tight bonds with the wood substrate. Fourier transform infrared (FTIR) microscopy analysis indicated that the in-situ generated polymer probably chemical bonded to the wood cell wall. The resultant PIW exhibited remarkably improved mechanical properties and durability relative to untreated wood. This was attributed to the possible grafting of the polymer onto the wood cell wall and the resultant reinforcement of the wood by the polymer.
  • Researchpp 7865-7876Taş, H. H., and Sevinçli, Y. (2015). "Properties of particleboard produced from red pine (Pinus brutia) chips and lavender stems," BioRes. 10(4), 7865-7876AbstractPDF
    The usability of lavender stems along with red pine chips was investigated as raw materials in the production of particleboard. Medium-density particleboard was manufactured using urea formaldehyde glue at three different ratios for five different mixture groups containing lavender stems and red pine chips. Some physical and mechanical properties of the boards were investigated. According to the statistical studies of the results, decreasing the ratio of lavender stems between board groups reduced the thickness swelling value. The internal bond strength, bending strength, and elastic modulus values of all board groups (%10-12 glued) were above the minimum values set by the TS-EN-312 standard for general purpose particleboard. According to these results, either lavender stems alone or together with red pine chips are suitable for use as a new raw material for particleboard manufacturing.
  • Researchpp 7877-7888Lu, P., Zhang, Y., Jia, C., Wang, C., Li, X., and Zhang, M. (2015). "Polyurethane from liquefied wheat straw as coating material for controlled release fertilizers," BioRes. 10(4), 7877-7888AbstractPDF
    A new controlled release fertilizer was developed by coating urea particles with bio-based polyurethane. Coating materials were synthesized from liquefied wheat straw, isocyanate, and castor oil. The effects of liquefied solvents, mass ratio of liquid to solid, size of wheat straw, and reaction time during liquefaction process on the nitrogen release rate of polyurethane-coated urea (PCU) were investigated and optimized. The nitrogen release characteristics of PCU were studied in both water and soil. The structural and chemical characteristics of PCU were examined. The PCU coating materials showed high density and good degradability, as well as superior controlled release properties. This product, with excellent controlled release properties, nontoxicity in soil, environmental friendliness, and low cost, could be especially useful in agricultural and horticultural applications.
  • Researchpp 7889-7897Park, J. H., Lee, J. Y., Kim, C. H., and Kim, E. H. (2015). "Effects of lignocellulosic bulking agents made from agricultural byproducts on physical properties and drying energy consumption of duplex board," BioRes. 10(4), 7889-7897AbstractPDF
    Though potentially useful, agricultural byproducts are often discarded because of the lack of specific applications in many industries. However, they have suitable properties for use in the paper industry, according to recent literature. In this study, the suitability of rice husk, peanut husk, and garlic stem as raw materials for the manufacture of a new lignocellulosic bulking agent was investigated, and the best material to replace a commercial wood powder, widely used in Korean duplex board mills, was determined. Many powders were manufactured from agricultural byproducts, and their effects on the physical properties and drying energy requirements of handsheets were evaluated compared to those of a commercial wood powder. All of the powders improved the bulk and dryness after wet pressing, but a reduction in paper strength was unavoidable. In particular, the powder made from rice husk showed a greater bulk and increase in dryness after wet pressing than the commercial wood powder. These findings indicated that these three agricultural byproducts could be used as raw materials for the manufacture of bulking agents, and rice husk was the best agricultural byproduct to replace commercial wood powder in duplex board mills.
  • Researchpp 7898-7906González-Márquez, A., Ahuactzin-Pérez, M., and Sánchez, C. (2015). "Lentinula edodes grown on Di(2-ethylhexyl) phthalate-containing media: Mycelial growth and enzyme activities," BioRes. 10(4), 7898-7906.AbstractPDF
    Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is widely used to soften plastic products. It is an endocrine-disrupting compound, widely considered an environmental contaminant that is difficult to remove or degrade. The radial growth rate (ur), mycelial biomass, intracellular and extracellular activities of laccase and esterase, intracellular and extracellular contents of protein and glycogen, and the contents of soluble and insoluble glucans were evaluated in colonies of Lentinula edodes, grown in various concentrations of DEHP (0, 750, 1200, and 1500 mg/L) on agar. Glucose and yeast extracts were added to all media. The highest ur was shown in medium lacking DEHP, followed by that shown in the medium containing 1500 mg of DEHP/L. The greatest protein extracellular contents were observed in medium with added DEHP. The largest extracellular glycogen contents and mycelial biomass were found in media containing 1200 and 1500 mg of DEHP/L, respectively. These results suggest that DEHP was degraded and used as a substrate by L. edodes during diauxic growth (glucose metabolized first, followed by DEHP), and laccases were more important than esterases in the metabolism of DEHP. L. edodes can be used to remove DEHP from phthalate-polluted environments.
  • Researchpp 7907-7920Long, Z., Wu, M., Peng, H., Dai, L., Zhang, D., and Wang, J. (2015). "Preparation and oil-resistant mechanism of chitosan/cationic starch oil-proof paper," BioRes. 10(4), 7907-7920.AbstractPDF
    Safe and environmentally friendly oil-resistant packaging paper is strongly desired in the food packaging industry. In the present work, chitosan (CTS) and chitosan/cationic starch (CTS/CS) coated papers were prepared and characterized. The results indicated that both the CTS and CTS/CS coated papers were highly oil resistant, and their oil resistance was increased with an increase in coating weight. The CTS/CS composite showed better thermal stability and water resistance than CTS. Paper coated with the CTS/CS composite containing 1:2 CTS to CS achieved an oil resistance level as required for food packaging. The mechanism of CTS/CS oil resistance, which has not been reported, was investigated by SEM, HPLC and particle size analyzer. The high oil resistance of the CTS/CS-coated paper was attributed to the formation of a film on the surface of the paper and the electrostatic binding between CTS and fatty acid to prevent oil from permeating and transferring.
  • Researchpp 7921-7935Wang, H., Yuan, H., Li, S., Li, Z., Jiang, M., and Tang, J. (2015). "Activity prediction of Schiff base compounds using improved QSAR models of cinnamaldehyde analogues and derivatives," BioRes. 10(4), 7921-7935.AbstractPDF
    In past work, QSAR (quantitative structure-activity relationship) models of cinnamaldehyde analogues and derivatives (CADs) have been used to predict the activities of new chemicals based on their mass concentrations, but these approaches are not without shortcomings. Therefore, molar concentrations were used instead of mass concentrations to determine antifungal activity. New QSAR models of CADs against Aspergillus niger and Penicillium citrinum were established, and the molecular design of new CADs was performed. The antifungal properties of the designed CADs were tested, and the experimental Log AR values were in agreement with the predicted Log AR values. The results indicate that the improved QSAR models are more reliable and can be effectively used for CADs molecular design and prediction of the activity of CADs. These findings provide new insight into the development and utilization of cinnamaldehyde compounds.
  • Researchpp 7936-7945Yang, Y., Zhan, T. Y., Lu, J. X., and Jiang, J. H. (2015). "Influences of thermo-vacuum treatment on colors and chemical compositions of alder birch wood," BioRes. 10(4), 7936-7945.AbstractPDF
    With high temperature-heat treatment, the dimensional stability and durability of wood is improved and wood color is darkened as well. In this paper, alder birch wood (Betula alnoides) was treated by the Thermo-Vacuum Treatment (TVT). The changes of wood color parameters and the chemical composition were determined by the CIE1976 L*a*b* method and the chemical analysis method, respectively. The results were revealed as follows: (1) A lower value of lightness, L*, and a higher value of total color difference, △E*, were obtained at the higher heat-treatment temperatures and longer treatment time. (2) The higher the heat-treatment temperatures and the longer the heat-treatment times were, the lower the contents of hemicellulose and cellulose were and the higher the content of lignin was. Moreover, Fourier Transform infrared spectroscopy (FTIR) analysis demonstrated that the characteristic absorption peaks of cellulose, hemicellulose, and lignin diminished. The acetylation reaction of hemicellulose and the degradation reaction of groups of lignin side chain occurred during TVT. (3) TVT degraded the chemical composition of cell walls, which resulted in further changes of the wood color. A significant correlation existed between the differences of color indices and the differences of the chemical composition after TVT.
  • Researchpp 7946-7957Qu, P., Huang, H., Wu, G., Zhao, Y., Jiang, X., and Chang, Z. (2015). "Preparation and degradation of seedling containers made from straw and hydrolyzed soy protein isolate modified urea-formaldehyde resins," BioRes. 10(4), 7946-7957.AbstractPDF
    Straw powders were blended with hydrolyzed soy protein isolate (HSPI) modified urea-formaldehyde (UF) resins to produce biodegradable seedling containers. The tensile strength and the degradability of the seedling containers were characterized. Moreover, the degradation behavior of modified UF resins was investigated using 15N isotopic tracing, dynamic mechanical analysis, 13C CP/MAS NMR spectroscopy, and a scanning electron microscope-energy dispersive spectrometer. The results showed that the best tensile strength of the seedling containers made from HSPI-modified UF resins was improved by 6% compared with the seedling containers made from UF resins. The degradability of the seedling containers made from modified UF resins was improved 8.8 times more than that of unmodified UF resins. HSPI can lower the cross-linking degree of UF resins. The HSPI and urea-formaldehyde molecular chains in the resins were decomposed simultaneously in the soil. After degradation, nodular particles that appeared to be coalesced by small globular particles remained. In the process of degradation, modified UF resins can provide a nitrogen source for crops.
  • Researchpp 7958-7969Hosseinihashemi, S. K., Anooshei, H., Aghajani, H., and Salem, M. Z. M. (2015). "Chemical composition and antioxidant activity of extracts from the inner bark of Berberis vulgaris stem," BioRes. 10(4), 7958-7969.AbstractPDF
    Extracts from the inner stem bark of Berberis vulgaris were analyzed for their antioxidant activity using the 1,1-dipheny-2-picrylhydrazyl (DPPH) method and compared with ascorbic acid (AA) and butylated hydroxytoluene (BHT). The most active extracts were analyzed for their chemical composition using gas chromatography-mass spectrometry. Acetone extract was found to be the most active as an antioxidant agent at 98.61%, which was higher than the value of vitamin C (93.03%) at the concentration of 0.16 mg/mL. The major components identified in the acetone extract were tetracosanoic acid, methyl ester (26.36%), followed by phthalic acid, diisooctyl ester (20.93%), 1,2-bis(trimethylsiloxy) ethane (10.26%), and 1,2-benzendicarboxylic acid, diisononyl ester (8.70%). The dissolved water:methanol (1:1 v/v) partitioned from acetone extract afforded 12 fractions; among them, fraction F11 was found to have good antioxidant activity (95.41%) at the concentration of 0.16 mg/mL. The major compounds identified in F11 were N-methyl-4-(hydroxybenzyl)-1,2,3,4-tetrahydroisoquinoloine (28.82%), 9-α-hydroxy-17β-(trimethylsilyl-oxy)-4-anderostene-3-methyloxime (13.97%), ribitol, pentaacetate (9.76%), 1-methyl-4-[4,5-dihydroxyphenyl]-hexahydropyridine (6.83%), and 2-ethylacridine (4.77%).
  • Researchpp 7970-7984Matthews, S., Toghyani, A. E., Eskelinen, H., Kärki, T., and Varis, J. (2015). "Manufacturability of wood plastic composite sheets on the basis of the post-processing cooling curve," BioRes. 10(4), 7970-7984.AbstractPDF
    Extruded wood-plastic composites (WPCs) are increasingly regarded as promising materials for future manufacturing industries. It is necessary to select and tune the post-processing methods to be able to utilize these materials fully. In this development, temperature-related material properties and the cooling rate are important indicators. This paper presents the results of natural cooling in a factory environment fit into a cooling curve function with temperature zones for forming, cutting, and packaging overlaid using a WPC material. This information is then used in the evaluation of manufacturability and productivity in terms of cost effectiveness and technical quality by comparing the curve to actual production time data derived from a prototype post-process forming line. Based on this information, speed limits for extrusion are presented. This paper also briefly analyzes techniques for controlling material cooling to counter the heat loss before post-processing.
  • Researchpp 7985-7997Xi, Y., Chang, Z., Ye, X., Du, J., Chen, G., and Xu, Y. (2015). "Enhanced methane production from anaerobic co-digestion of wheat straw and herbal-extraction process residues," BioRes. 10(4), 7985-7997.AbstractPDF
    The efficient biosynthesis of methane from renewable biomass resources is discussed in this paper. Herbal-extraction process residues (HPR) are an excellent raw material for anaerobic digestion because of their abundant trace elements and fermentation stability. Anaerobic co-digestion of wheat straw with HPR was evaluated at HPR/wheat straw ratios (based on total solids (TS), of wheat straw) of 3%, 5%, and 10 % with anaerobic sludge at 35±1 °C during 30-d anaerobic digestion. The best performance was achieved with 5% HPR added to the reactor, with cumulative methane production of 13,130 mL and cumulative methane yield of 260.5 mL/g TSadded, respectively. Cumulative methane production increased by 31.4% compared to the 9995 mL achieved in mono-digestion with wheat straw. Furthermore, higher activities of protease and total dehydrogenase and higher ATP levels were displayed during the co-digestion process. The high methane yield in this study demonstrates the great potential of co-digestion of renewable biomass as a feedstock for the economical production of methane.
  • Researchpp 7998-8013Fan, L., Ruan, R., Liu, Y., Wang, Y., and Tu, C. (2015). "Effects of extraction conditions on the characteristics of ethanol organosolv lignin from bamboo (Phyllostachys pubescens Mazel)," BioRes. 10(4), 7998-8013.AbstractPDF
    The structure and properties of ethanol organosolv lignin (EOL) extracted from bamboo under various conditions were characterized. EOL yield increased at high temperatures of 160 to 200 °C and a reaction time of 1 to 3 h. The nitrogen content in lignin was low, with a maximum of 0.62%. The carbon content increased with increasing temperature and prolonged time, whereas oxygen content showed an inverse trend. EOL extracted from bamboo showed high purity levels (more than 95.5% Klason lignin) with low impurity contents (carbohydrate and ash). The severity of the process increased the carboxylic acid and phenolic hydroxyl group contents and also decreased the methoxyl group content. The molecular weight of EOL varied depending on the extraction condition. The FT-IR and NMR spectra revealed that the main structure did not significantly change. From the spectra, it is clear that EOL extracted from bamboo can be classified as an HGS (H--p-hydroxyphenyl, G--guaiacyl, and S--syringyl, respectively) type. Clear β-O-4, β-β, and β-5’ linkages were observed.
  • Researchpp 8014-8024Basso, M. C., Pizzi, A., and Delmotte, L. (2015). "A new approach to environmentally friendly protein plastics and foams," BioRes. 10(4), 8014-8024.AbstractPDF
    New formaldehyde-free and isocyanate-free bioplastics and biofoams were prepared by reacting ovoalbumin and dimethyl carbonate (DMC) at a moderate temperature. Analysis by 13C NMR revealed a reaction between dimethyl carbonate and the amino and/or hydroxyl groups of the side chain of amino acids. The densities were between 0.6 and 1.1 g/cm3 for the obtained plastics. Thermal and mechanical resistances peaked at 175 °C and 7.7 MPa, respectively. The Brinell hardness was 2. The prepared foam exhibited a density of 0.1 g/cm3 and an open cell structure. Impregnation with hexamethylene diamine (DAH) allowed for the preparation of materials with elastic mechanical behavior through the reaction of DAH and DMC. The new plastics and foams derived from ovoalbumin protein were markedly more environmentally friendly.
  • Researchpp 8025-8038Yusof, N. A., Mukhair, H., Malek, E. A., and Mohammad, F. (2015). "Esterified coconut coir by fatty acid chloride as biosorbent in oil spill removal," BioRes. 10(4), 8025-8038.AbstractPDF
    Coconut coir, an agricultural waste, was chemically modified using esterification by fatty acid chloride (oleoyl chloride and octanoate chloride) for oil spill removal purposes. The modified coir (coir-oleate and coir-octanoate) were characterized by spectroscopy, thermal studies, contact angle, and morphological studies. The modified coir exhibited an enhancement towards the hydrophobic property but a decreased thermal stability. The oil adsorption performance was tested using a batch adsorption system. The effect of sorbent dosage, oil concentration, and effect of adsorption time on the adsorption capacity of the modified coir were also studied. From the analysis, the long chain oleoyl chloride (C18) was shown to be a better modifier compared to octanoate chloride (C8). The isotherm study indicated that the oil adsorption fitted well to a Langmuir model rather than Freundlich model. From the kinetic study, the result revealed a good fit in pseudo-second order model for all samples studied. The study therefore suggests that esterified coconut coir can serve as a potential biomaterial for the adsorption of spilled oil during operational failures.
  • Researchpp 8039-8047Jablonský, M., Škulcová, A., Kamenská, L., Vrška, M., and Šima, J. (2015). "Deep eutectic solvents: Fractionation of wheat straw," BioRes. 10(4), 8039-8047.AbstractPDF
    Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.
  • Researchpp 8048-8057Ma, Q., and Yang, R. (2015). "Alkaline xylanase produced by Trichoderma reesei: Application in waste paper pulp bleaching," BioRes. 10(4), 8048-8057.AbstractPDF
    In this work, a facile, green approach to natural biomass bleaching is reported. It was found that Trichoderma reesei could produce alkaline xylanase and xylanase is highly active in alkaline environments. It has good environmental adaptability and could be used to reduce the use of bleaching chemicals for the pretreating process and degradation of hemicellulose so as to break the linkages of Lignin-carbohydrate complexes (LCCs). These particular properties benefit the pulp bleaching process and can improve the physical properties of the resulting paper. The optimum bleaching process conditions were as follows: dosage, 12 U/g; pH, 8 to 9; time, 60 minutes; and temperature, 70 °C. The xylanase can decrease the chemical oxygen demand (COD) of bleaching effluent by 41% as compared to the blank. Finally, after xylanase pretreatment, the whiteness, yellow index, tensile index, burst index, and elongation of the resulting paper were 54.8% ISO, 1.73, 33.93 N·m/g, 2.91 KPa·m2/g, and 2.91%, respectively.
  • Researchpp 8058-8075Qu, J. J., Zang, T. T., Gu, H. D., Li, K. K., Hu, Y., Ren, G. M., Xu, X. H., and Jin, Y. (2015). "Biosorption of copper ions from aqueous solution by Flammulina veluptipes spent substrate," BioRes. 10(4), 8058-8075.AbstractPDF
    To remove heavy metals from aqueous solution and reclaim valuable materials from mushroom byproducts, Flammulina velutipes spent substrate (FVSS) was developed as a novel biosorbent for copper ion removal. Batch experiments demonstrated that ion removal was pH-, biosorbent dosage- and initial metal concentration dependent. The maximum removal capacity of 15.56 mg/g was achieved at pH 6.0 with a biomass dosage of 3.0 g/L and initial copper ion concentration of 50 mg/L. The adsorption data were in compliance with the Langmuir isotherm and a pseudo-second-order kinetic model. Thermodynamic studies revealed the biosorption process was endothermic, random, and spontaneous. FT-IR spectral analysis confirmed that hydroxyl, amino, carbonyl, and phosphate groups on the biosorbent surface were involved in the biosorption. The uneven surface and porous structure of the biosorbent was propitious for quickly capturing the metal ions from aqueous solution. EDX spectra revealed that the copper ions were loaded on the surface of the biosorbent. XRD patterns showed the formation of copper-containing compounds.
  • Researchpp 8076-8088Mathias, J. D., Alzina, A., Grédiac, M., Michaud, P., Roux, P., De Baynast, H., Delattre, C., Dumoulin, N., Faure, T., Larrey-Lassalle, P., Mati-Baouche, N., Pennec, F., Sun, S., Tessier-Doyen, N., Toussaint, E., and Wei, W. (2015). "Upcycling sunflower stems as natural fibers for biocomposite applications," BioRes. 10(4), 8076-8088.AbstractPDF
    One of the big global, environmental, and socioeconomic challenges of today is to make a transition from fossil fuels to biomass as a sustainable supply of renewable raw materials for industry. Growing public awareness of the negative environmental effects of petrochemical-based products adds to the need for alternative production chains, especially in materials science. One option lies in the value-added upcycling of agricultural by-products, which are increasingly being used for biocomposite materials in transport and building sector applications. Here, sunflower by-product (obtained by grinding the stems) is considered as a source of natural fibers for engineered biocomposite material. Recent results are shown for the main mechanical properties of sunflower-based biocomposites and the socioeconomic impact of their use. This paper demonstrates that sunflower stem makes a good candidate feedstock for material applications. This is due not only to its physical and chemical properties, but also to its socioeconomic and environmental rationales.
  • Researchpp 8089-8097Wang, M., He, W., Jin, X., and Song, X. (2015). "Oxidized konjac glucomannan as a paper strength agent," BioRes. 10(4), 8089-8097.AbstractPDF
    A paper strength agent is an important type of chemical additive used in the papermaking industry. In this work some new paper strengthening agent samples were obtained by treating konjac glucomannan with hydrogen peroxide under acidic conditions, and their effects on paper properties were studied. Results showed that oxidized konjac glucomannan (OKG) can improve the paper properties effectively. When 1% oxidized glucomannan (oxidation 60 min, 35 °C) was added, the burst index, tensile index, and folding endurance were increased by 7.0%, 16.9%, and 102.3%, respectively, compared to the control. With increasing of oxidation time, the paper strength increased first and then decreased, reaching the maximum in 60 min. In addition, OKG can improve the properties of recycled paper more significantly. When the pH of paper making system was 7, the tensile index, burst index, and folding endurance of the recycled paper were increased by 22.2%, 19.9%, 59.9%, respectively, compared to the control. SEM analysis showed that paper strengthening agent resulted in a more contiguous junction between the fibers in paper.
  • Researchpp 8098-8134Reeb, C. W., Venditti, R., Hays, T., Daystar, J., Gonzalez, R., and Kelley, S. (2015). "Environmental LCA and financial analysis to evaluate the feasibility of bio-based sugar feedstock biomass supply globally: Part 1. Supply chain analysis," BioRes. 10(4), 8098-8134.AbstractPDF
    Chemical production from crude oil represents a substantial percentage of the yearly fossil fuel use worldwide, and this could be partially offset by renewable feedstocks such as woody biomass and energy crops. Past techno-economic and environmental analyses have been conducted for isolated feedstocks on a regional or national scope. This study encompasses complete supply chain logistics analysis, delivered cost financial analysis, national availability, and environmental life cycle assessment (LCA) for 18 selected cellulosic feedstocks from around the world. A biochemical conversion route to monomeric sugars is assumed for estimated sugar yields and biosugar feedstock cost analysis. US corn grain was determined to have the highest delivered cost, while rice hulls in Indonesia resulted in the lowest cost of the feedstocks studied. Monomeric sugar yields from literature ranged from 358 kg BDMT-1 for US forest residues to 700 kg BDMT-1 for corn syrup. Environmental LCA was conducted in SimaPro using ecoinvent v2.2 data and the TRACI 2 impact assessment method for mid-point impacts cradle-to-incoming biorefinery gate. Carbon absorption during biomass growth contributed most substantially to the reduction of net global warming potential. Rice hulls and switchgrass resulted in the highest global warming potential, followed closely by corn and Thai sugarcane bagasse. Contribution analysis shows that chemical inputs such as fertilizer use contribute substantially to the net environmental impacts for these feedstocks.
  • Researchpp 8135-8147Li, R., Zhang, Y., Cao, Y., and Liu, Z. (2015)."Ink penetration of uncoated inkjet paper and impact on printing quality," BioRes. 10(4), 8135-8147.AbstractPDF
    This study investigated ink penetration through imaging technology, first by gray and contour mapping and then calculating the ink penetration depth by programing. Next, a series of further analyses were carried out, including average ink permeability, ink distributions, and printability of different uncoated inkjet paper with different parameters. The impact on ink penetration of the microstructure and hydrophilicity of the uncoated paper was also studied. The experimental results indicated that paper specimens with sizing agent were resistant to the ink, resulting in a slow and shallow ink penetration. Paper containing filler had a more hydrophilic surface and porous structure, leading to a faster and deeper ink penetration. However, the calendering operation could make the paper structure more compact and reduce the porosity and penetration depth. When an appropriate combination of sizing agent, filler content, and the calendering process was utilized, a more stable hue could be produced with improvements in optical density, saturation, and color.
  • Researchpp 8148-8167Žepič, V., Poljanšek, I., Oven, P., Škapin, A. S., and Hančič, A. (2015). "Effect of drying pretreatment on the acetylation of nanofibrillated cellulose," BioRes. 10(4), 8148-8167.AbstractPDF
    The aim of this study was to evaluate the effect of different morphologies of solvent-exchanged (NFCSE), spray-dried (NFCSD), and freeze-dried (NFCFD) nano-fibrillated cellulose on the susceptibility to surface modification with the acetic anhydride/pyridine system. The degree of substitution (DS), morphology, degree of crystallinity (Icr), hydrophobicity, and thermal stability of acetylated products were examined. Acetylated NFCSD and NFCFD had higher DS than acetylated NFCSE, suggesting that drying pre-treatment increased the susceptibility of NFC for acetylation. The morphology of acetylated NFCFD and NFCSD with higher DS was different from unmodified samples, while that of NFCSE was not affected by acetylation. Microspheres of acetylated NFCSD started to dissolve when the highest DS was reached. As opposed to unmodified NFCFD, the nanofibrillar units of acetylated NFCFD became individualised at lower DS. Acetylated samples had lower Icr than the unmodified samples. A significant increase in the contact angle was observed at higher DS of acetylated NFC samples. Acetylation markedly elevated the thermal stability of the acetylated NFC samples.
  • Researchpp 8168-8180Vaz, S., Jr. and Donate, P. M. (2015). "Microwave-assisted green production of furfural from D-xylose of sugarcane bagasse," BioRes. 10(4), 8168-8180.AbstractPDF
    D-xylose is a component of sugarcane bagasse that can be used as a renewable resource for the production of a variety of chemicals. By means of catalytic reactions in an aqueous medium, it was determined that D-xylose can efficiently be converted into furfural by the application of microwave as a green synthetic methodology. The highest yields of furfural were obtained at a HCl concentration of 4 mg/mL. When the reaction was performed at 200 °C, an optimum yield of 64% of furfural was observed after 10 min of reaction time, with 95% of the D-xylose being converted.
  • Researchpp 8181-8193Dömény, J., Čermák, P., Pařil, P., Fodor, F. P., Dejmal, A., and Rademacher, P. (2015). "Application of microwave heating for acetylation of beech (Fagus sylvatica L.) and poplar (Populus hybrids) wood," BioRes. 10(4), 8181-8193AbstractPDF
    Microwave and conventional acetylation of wood was carried out to determine its efficacy on the material properties. Beech (Fagus sylvatica L.) and poplar (Populus hybrids) samples with dimensions 14 mm × 14 mm × 14 mm were impregnated using acetic anhydride, and chemical reactions were initiated by microwave and conventional heating. The microwave acetylation process was carried out using laboratory equipment at a frequency of 2.45 GHz in several testing modes to reduce time of the reaction. The uptake of substance, equilibrium moisture content, wood swelling, and dimensional stability were determined in order to evaluate the efficacy and degree of acetylation. Both microwave and conventional heating positively affected the selected material properties. The results showed that no significant differences were found between microwave and conventional heating; therefore, microwave heating can be used as a valid replacement in the acetylation process. Microwave power of 2 kW and 0.1 m∙min-1 conveyor speed were the optimum conditions for microwave acetylation. These process parameters resulted in 39.4% ASE T and 35.2% ASE R for beech and 38.0% ASE T and 16.3% ASE R for poplar samples. This work provides insight into the details of wood acetylation using microwave heating.
  • Researchpp 8194-8207Ho, L. S., Tan, B. A., Md Noh, N., A. Talib, S. S., Ithnin, N., Jeffery Daim, L. D., Eng Keong, T. O., and Mohd Yusof, H. (2015). "Preliminary analysis of lignocellulose content and monolignol composition of oil palm trunk from two different genetic backgrounds," BioRes. 10(4), 8194-8207.AbstractPDF
    A preliminary investigation of chemical and lignin composition was conducted from samples of oil palm trunk of two different genetic backgrounds. A significant difference in percent (%) of standing palms was noted for the two different genetic backgrounds after 24 years of planting. Given that these palms were planted in neighboring fields, the objective of this preliminary study was to compare the chemical composition, as well as the lignin composition of the two palm varieties. When comparing the two populations, significant differences were observed in the structural carbohydrate composition and the lignin composition. This research constitutes the first reporting on the pyrolysis-gas chromatography-mass spectrometer analysis of oil palm trunk lignin composition.
  • Researchpp 8208-8224Gao, X., Zhuang, S., Jin, J., and Cao, P. (2015). "Bound water content and pore size distribution in swollen cell walls determined by NMR technology," BioRes. 10(4), 8208-8224.AbstractPDF
    Nuclear magnetic resonance (NMR) relaxation time distributions can provide detailed information about the moisture in wood. In this paper, the bound water content and pore size distributions in swollen cell wall of two kinds of softwoods (Pinus sylvestris and Cunninghamia lanceolata) and three kinds of hardwoods (Populus sp., Fraxinus excelsior L., and Ochroma lagopus) were determined by NMR cryoporometry. The total bound water content of swollen cell wall almost exceeds 35%, based on dry mass, which is obviously higher than the fiber saturation point (FSP) (appr. 30%) measured by the extrapolation method. The bound water content of different species is consistent with the hypothesis that with the decrease of basic density, the more bound water could be contained in wood. The proportion of the pore diameter smaller than 1.59 nm is higher than 70%, and the proportion of the pore diameter larger than 4 nm is no more than 10%.
  • Researchpp 8225-8237Ma, J., Wang, Z., Zhou, X., and Xiao, H. (2015). "Self-reinforced grease-resistant sheets produced by paper treatment with zinc chloride solution," BioRes. 10(4), 8225-8237.AbstractPDF
    A method for the production of paper with high strength and grease resistance was developed. Filter paper was impregnated by an aqueous solution of zinc chloride at a fixed temperature for several seconds. Swelling and partial dissolution of the cellulose fibers resulted in strong and compact paper. Various influencing factors were investigated in an attempt to improve the grease resistance of the paper. In addition, the structural properties of the zinc chloride-treated paper were investigated using a Fourier transform infrared (FT-IR) spectrometer, X-ray diffraction (XRD), and a scanning electron microscope (SEM). Paper treated in this manner was completely grease resistant, had greater stretch, and twice as high tensile strength when compared with untreated paper, while its burst strength more than doubled. Paper treated according to this method had the skeleton of un-dissolved cellulose fibers and the matrix of gelled cellulose. The cellulose of the paper was not chemically modified during this process.
  • Researchpp 8238-8252Xing, D., Wang, S., and Li, J. (2015). "Effect of artificial weathering on the properties of industrial-scale thermally modified wood," BioRes. 10(4), 8238-8252.AbstractPDF
    Thermally modified wood is widely used in cladding, decking, and other construction projects that are meant for outdoor exposure. The purpose of this study was to investigate changes in the color, microstructure, and chemical composition of heat-treated, Larix spp. wood that was exposed to artificial weathering. In this study, accelerated weathering tests (UV and moisture) were conducted over a period of 3000 h. Photodegradation of both heat-treated and untreated wood was evaluated in terms of color, microstructure, and chemical changes that were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Ultra-violet radiation caused the degradation of lignin and extractives of wood, resulting in an immediate color change of the wood. The SEM observation of the heat-treated wood showed deformations and cracks in both treated and untreated samples. Irradiation resulted in a pronounced reduction in the absorption intensity and broadening of the FTIR spectra. It was found that the industrial heat-treatment of wood products resulted in more color stability than untreated wood during the early stages of weathering. Thermal modification was found, however, was ineffective in improving the UV resistance wood over long-term photodegradation conditions.
  • Researchpp 8253-8267Chen, W., Chen, M., and Zhou, X. (2015). "Characterization of biochar obtained by co-pyrolysis of waste newspaper with high-density polyethylene," BioRes. 10(4), 8253-8267.AbstractPDF
    The pyrolysis of waste newspaper (WP) and co-pyrolysis of waste newspaper with high-density polyethylene (HDPE) (1:1 wt%) were carried out in a quartz tube at 500 °C to obtain biochars. The biochars were characterized in detail by X-ray diffraction (XRD), thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), automated specific surface area and pore size analyzer, and Raman spectroscopy to determine their physical and chemical properties. The analysis results for WP/HDPE-derived biochar (CWH) were compared to WP-derived biochar (CWB). The CWH had lower oxygen-containing groups, increased aromatic structure, higher calorific value, higher fuel ratio, and greater porosity development. CWH is more appropriate as solid fuel, soil adsorbent, or activated carbon precursor as compared to CWB.
  • Researchpp 8268-8280Ireana Yusra, A. F. I., Abdul Khalil, H. P. S., Hossain, M. S., Davoudpour, Y., Astimar, A. A., Zaidon, A., Dungani, R., and Mohd Omar, A. K. (2015). "Characterization of plant nanofiber-reinforced epoxy composites," BioRes. 10(4), 8268-8280.AbstractPDF
    In the present study, oil palm empty fruit bunch (OPEFB) fibers were taken from a 25-year-old oil palm tree. The cellulosic nanofiber (CNF) was isolated from the OPEFB using a chemo-mechanical process and utilized as reinforcement in an epoxy matrix. Various CNF loading percentages (0 to 0.75%) were applied in the epoxy matrix to explore the potential of using OPEFB-CNF as reinforcement. The morphological, mechanical, physical, and thermal characteristics of the OPEFB nanofiber-reinforced epoxy composites were evaluated. Results showed that the 0.25% and 0.5% CNF loadings were homogenously distributed and well-dispersed in the composite matrix. Conversely, agglomeration was detected in the matrix with 0.75% CNF loading. Determination of the water absorption behavior of CNF-reinforced epoxy composites at various loadings revealed that the physical properties of the composites increased with reinforcement loading. Furthermore, the analyses of the mechanical and thermal properties of the CNF-reinforced composites revealed that the incorporation of OPEFB-CNF enhanced the mechanical performance and thermal stability up to 0.5% loading.
  • Researchpp 8281-8294Borůvka, V., Zeidler, A., and Holeček, T. (2015). "Comparison of stiffness and strength properties of untreated and heat-treated wood of Douglas fir and alder," BioRes. 10(4), 8281-8294.AbstractPDF
    This paper investigates the effect of heat treatment temperature on the stiffness and strength properties of Douglas fir (Pseudotsuga menziesii Franco) and common alder (Alnus glutinosa Gaertn.) woods. Two temperatures of heat treatment were used: 165 and 210 °C. The effects of dynamic elasticity modulus, static elasticity modulus, impact toughness, bending strength, and density were evaluated. It is already understood that the mechanical properties, primarily the bending strength, decreases with increasing temperature. In contrast to the favorable stability in shape and dimension that was achieved, the changes in the woods’ properties with temperature were mostly negative. Higher heat treatment temperatures corresponded with lower stiffness and strength properties. For higher temperature treatments, above 200 °C, deterioration of the tested properties was noticable as a result of the significant changes in the wood chemical structure. Even the positive effect of the equilibrium moisture decrease was not able to counterbalance the unfavorable changes. Moreover, it was observed that as the hemicellulose content is higher in alder wood, density, static bending strength, and toughness all decreased steadily at high temperatures, compared to Douglas fir wood.
  • Researchpp 8295-8311Zhang, Z. B., Lu, Q., Ye, X. N., Li, W. T., Hu, B., and Dong, C. Q. (2015). "Selective analytical production of 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one from catalytic fast pyrolysis of cellulose with zinc-aluminium layered double oxide catalyst," BioRes. 10(4), 8295-8311.AbstractPDF
    Zinc-aluminium layered double oxide (Zn-Al-LDO) catalysts derived from layered double hydroxides (LDHs) were prepared and used for the catalytic fast pyrolysis of cellulose to selectively produce 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one (LAC), which is a valuable anhydrosugar derivative. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were performed to investigate the LAC production under different reaction conditions. The results indicated that the Zn-Al-LDO catalysts were capable of greatly inhibiting the pyrolytic formation of levoglucosan (LG) and capable of promoting the formation of LAC and certain other products. The catalyst with the Zn/Al molar ratio of 2 exhibited the best catalytic capacity for LAC production. Both pyrolysis temperature and the catalyst-to-cellulose ratio affected the pyrolytic product distribution remarkably. The maximal LAC yield was obtained at the pyrolysis temperature of 350 °C and catalyst-to-cellulose ratio of 4 and featured a peak area percentage of 21.9% (calculated by GC/MS), compared with only 3.0% from the non-catalytic process. In addition, the LDO catalyst performed better than the previously reported montmorillonite K-10 catalyst on the enhancement of LAC production.
  • Researchpp 8312-8324Lourenço, A. F., Gamelas, J. A. F., Sequeira, J., Ferreira, P. J., and Velho, J. L. (2015). "Improving paper mechanical properties using silica-modified ground calcium carbonate as filler," BioRes. 10(4), 8312-8324.AbstractPDF
    The ability to increase the filler content of paper without significantly sacrificing its mechanical strength is of high interest for papermakers. In this work, three samples of ground calcium carbonate (GCC), differing in size and in brightness, modified with silica via the sol-gel method, were used as fillers in papermaking. Handsheets were produced using a eucalyptus kraft pulp furnish and with a filler amount near 20%. It was found that not only were the strength properties of the handsheets produced with the modified GCCs always significantly better than those obtained with the unmodified GCCs (e.g., the tensile index exhibited improvements of 16 to 20%), but bulk also was increased (by 7 to 13%). Some decreases in the light scattering and opacity values were noted when using the modified GCC, but the brightness was roughly the same. The enhanced fiber-to-filler bonding may be attributed to the hydrogen bonding between the cellulosic fibers and the hydroxyl groups of the silica coating the calcium carbonate particles.
  • Researchpp 8325-8338Taverna, M. E., Ollearo, R., Morán, J., Nicolau, V., Estenoz, D., and Frontini, P. (2015). "Mechanical evaluation of laminates based on phenolic resins using lignins as partial substitutes for phenol," BioRes. 10(4), 8325-8338.AbstractPDF
    Reducing the consumption of phenol during synthesis of phenolic resins is of great technological and scientific interest because of its economic and environmental implications. In this work, the use of hydroxymethylated lignins as a partial replacement for phenol in resol phenol-formaldehyde resins used for the production of decorative laminates was experimentally studied. The work involved: i) the industrial synthesis of traditional and modified resols with 10%w/w of sodium lignosulfonate and kraft-type lignin; ii) the industrial impregnation of kraft-type paper with the produced resins; iii) the production of laminates on both laboratory and industrial scales; and iv) the measurement of their final properties. The mechanical performance of the laminates was evaluated via the determination of the Young modulus, bending strength, biaxial impact strength, and Mode-I interlaminar fracture toughness. The (modified and traditional) laminates exhibited statistically significant differences in mechanical properties. However, the partial lignin replacement did not produce effects that were detrimental to the overall performance of the decorative laminates.
  • Researchpp 8339-8351Wen, X., Bao, D., Chen, M., Zhang, A., Liu, C., and Sun, R. (2015). "Preparation of CMC/HEC crosslinked hydrogels for drug delivery," BioRes. 10(4), 8339-8351.AbstractPDF
    A novel crosslinked hydrogel was prepared from sodium carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC) using ammonium persulfate as an initiator and methylenebisacrylamide as a crosslinker for drug delivery. The chemical structure of the copolymer was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the morphology was observed under scanning electron microscopy. The swelling behavior of the hydrogels confirmed the pH- and ionic strength-sensitivity. The reversibility of the hydrogels and the on-off switching behavior were also investigated, providing the potential for drug delivery. The release of bovine serum albumin (BSA) from drug-loaded hydrogels was studied at different pH conditions to simulate gastrointestinal conditions. The amount of BSA released from the hydrogels at pH 1.2 was relatively low (17.8%), while 85.2% was released at pH 7.4. According to the results, the CMC/HEC hydrogel has the potential for use in the controlled release of oral medication.
  • Researchpp 8352-8363Cheng, D., Gu. J., Xu, B., and Li, Y. (2015). "Effect of (NH4)2SO4 concentration on the pyrolysis properties of rayon fiber from bamboo," BioRes. 10(4), 8352-8363.AbstractPDF
    (NH4)2SO4 solution was employed to pre-treat regenerated cellulose fiber (from bamboo) using an ultrasonic method, and then the material was heat-treated at 250 °C. Scanning electron microscopy revealed that erosion and cracks of the fiber surface increased after being impregnated with (NH4)2SO4 combined with ultrasonic pretreatment. There was a small change in the intensity and the position of some peaks in the Fourier transform infrared spectra, and in the heat treatment, partial pyrolysis of the cellulose occurred. The data showed that for the cellulose fiber pretreated with 5 wt% (NH4)2SO4 the decomposition temperature shifted to the lower side (252 °C), and the decomposition range (180 °C to 454 °C) was wider than for the other impregnation fibers and reference. However, the rate of decomposition was different with different concentrations of (NH4)2SO4. The C content of heat-treated fiber with 5 wt% (NH4)2SO4 increased to 52%. The above results indicated that the (NH4)2SO4 was an effective catalyst to pretreat regenerated cellulose fiber in the pathway of pyrolysis.
  • Researchpp 8364-8377Mohanta, N., and Acharya, S. K. (2015). "Mechanical and tribological performance of Luffa cylindrica fibre-reinforced epoxy composite," BioRes. 10(4), 8364-8377.AbstractPDF
    This work focuses on the mechanical properties and solid particle impact behaviour of Luffa cylindrica fibre (LCF)-reinforced epoxy composites. Single (SL)-, double (DL)-, and triple (TL)-layered composites were prepared using the general hand lay-up technique. The erosive wear test was carried out using an air jet erosion tester according to the ASTM G76 standard. The erodent used was silica sand particles (200 ± 50 µm). The experimental parameters studied for the erosion rate of the LCF epoxy composites were impingement angle (30° to 90°) and particle velocity (48 m/s to 82 m/s). Analysis of the results revealed that at the peak erosion rate, semi ductile behaviour of the composite was apparent. Possible erosion mechanisms were discussed and were investigated using scanning electron microscopy (SEM).
  • Researchpp 8378-8396Buck, D., Wang, X., Hagman, O., and Gustafsson, A. (2015). "Comparison of different assembling techniques regarding cost, durability, and ecology - A survey of multi-layer wooden panel assembly load-bearing construction elements," BioRes. 10(4), 8378-8396.AbstractPDF
    Wood is a pure, sustainable, renewable material. The increasing use of wood for construction can improve its sustainability. There are various techniques to assemble multi-layer wooden panels into prefabricated, load-bearing construction elements. However, comparative market and economy studies are still scarce. In this study, the following assembling techniques were compared: laminating, nailing, stapling, screwing, stress laminating, doweling, dovetailing, and wood welding. The production costs, durability, and ecological considerations were presented. This study was based on reviews of published works and information gathered from 27 leading wood product manufacturing companies in six European countries. The study shows that the various techniques of assembling multi-layer wooden construction panel elements are very different. Cross laminated timber (CLT) exhibited the best results in terms of cost and durability. With regard to ecological concerns, dovetailing is the best. Taking into account both durability and ecological considerations, doweling is the best. These alternatives give manufacturers some freedom of choice regarding the visibility of surfaces and the efficient use of lower-quality timber. CLT is the most cost-effective, is not patented, and is a well-established option on the market today.
  • Researchpp 8397-8404Si, C. L., Huang, X. F., An, L. L., Fan, S., Liu, C. Y., Xie, D. N., Hong, Y. M., and Chen, J. (2015). "Extraction and structural characterization of flavoniods from twigs of Sophora japonica," BioRes. 10(4), 8397-8404.AbstractPDF
    Flavonoids represent a large group of polyphenols that have been recognized to exert a wide range of biological effects, such as anticancer, inflammation inhibition, anti-aging, and neuroprotective activities. In the forest industry, tree twigs have been treated as residues; however, tree twigs could be a rich source of high-value added compounds, which have been relatively unexplored. In this study, an investigation into the chemical constituent of extractives from S. japonica twigsresulted in the isolation of a new (Z)-caffeoyl flavonol glycoside that was elucidated as myricetin 3-O-(4''-(Z)-caffeoyl)-α-rhamnopyranoside (IV). The structure of the new compound was established mostly on the basis of extensive spectroscopic techniques and other physiochemical evidences. Among the three known flavonoids extracted in this work, including isoquercitrin (I), isorhamnetin 3′-O-β-D-glucopyranoside (II), and myricitrin (III), II and III have never been previously reported in the Sophora genus.
  • Researchpp 8405-8413Gangwar, A. K., Prakash, N. T., and Prakash, R. (2015). "Amenability of acacia and eucalyptus hardwood pulps to elemental chlorine-free bleaching: Application and efficacy of microbial xylanase," BioRes. 10(4), 8405-8413AbstractPDF
    This study outlines the results of a biobleaching study of acacia (A. mangium) and eucalyptus (E. globulus) hardwood kraft pulps with commercial xylanase (Optimase CX 72 L). The comparative study was carried out using an elemental chlorine-free (ECF) bleaching sequence (D0EPD1D2) after the enzyme (X) stage. The enzyme treatment resulted in improved optical properties with a reduction in bleach chemical consumption. At an equivalent bleach chemical consumption, a brightness gain of 2.1 and 1.7 units and a whiteness gain of 2.7 and 2.3 units were observed with xylanase treatment in acacia and eucalyptus pulps, respectively. In ECF bleaching using the D0EPD1D2 sequence, a final brightness was achieved to the extent of 90% ISO and 89% ISO for acacia and eucalyptus, respectively, at an equivalent charge of bleach chemicals. The post-color (PC) number was also reduced by up to 45% for both hardwood pulps compared with the control. The bleachability of acacia was observed to be significantly higher than that of eucalyptus. In addition, a 17.0% and 23.0% reduction in chlorine dioxide and sodium hydroxide, respectively, were obtained for both hardwood pulps after xylanase pre-bleaching, thus indicating an environmentally friendly approach to the process.
  • Researchpp 8414-8425Wang, J., Cao, P., Guo, X., Xue, H., Jia, G., Wang, B. (2015). "Effect of process parameters on cutting forces and surface roughness during peripheral up milling of bamboo scrimber," BioRes. 10(4), 8414-8425.AbstractPDF
    The effects of milling process parameters on cutting forces and surface roughness were studied during peripheral up milling of bamboo scrimber. The study results indicated that the effect of feed rate on cutting force components Fx, +Fy, -Fy, and surface roughness Ra were the most significant compared to spindle speed and cut depth during longitudinal milling. Fx, +Fy, -Fy, and Ra decreased slightly with increasing spindle speed, but increased greatly with increasing feed rate. In addition, cutting direction had a great effect on the cutting force components Fx and +Fy, as well as the machined surface roughness Ra. Fx, +Fy, and Ra during longitudinal cutting were always larger than those during end-grain cutting. Decreasing the feed rate appropriately could greatly improve the quality of the machined surface.
  • Researchpp 8426-8438An, X., Sui, Q., Sun, F., Ma, Z., Jiang, S., Ji, B., and Fan, H. (2015). "Compression responses of bio-cellular luffa sponges," BioRes. 10(4), 8426-8438.AbstractPDF
    Crushing behaviors of luffa sponges were studied through mechanical experiments. Controlled by four-order hierarchical and anisotropic structures, luffa sponges exhibit anisotropic responses along axial, radial, and circumferential directions. The ultra-thin but stiff inner surface layer dominates the crushing behavior, endowing the axially compressed luffa cylinder with structural integrity, enhancing the elastic deformation and yielding strength. In radial, circumferential, and lateral compressions, after removing the inner surface layer, luffa sponges are compliant and have large quasi-linear deformation before densification, without a plateau characterized by yielding and deformation. Immersed into water, crushed luffa sponge cylinders recover their geometry completely. However, compression strength is only partially restored. Gradual damage of the inner surface layer in water immersing/drying cycles greatly weakens the compression strength. In the case of removal of the inner surface layer, crushed luffa sponge cylinders completely restore their quasi-linear deformation ability during the water immersing/drying cycles.
  • Researchpp 8439-8449Khademi Eslam, H., and Samariha, A. (2015). "Effect of steamed and non-steamed Populus deltoides fiber on the physical, mechanical, and morphological characteristics of composites made from virgin polypropylene," BioRes. 10(4), 8439-8449.AbstractPDF
    The effects of steamed Populus deltoides fiber were studied relative to the physical, mechanical, and morphological characteristics of composites made from virgin polypropylene. Fibers of Populus deltoides were used during the reinforcement phase at 180 °C for 1 h. The tests were carried out with 57% of virgin polypropylene that was combined with 3% of maleic anhydride-modified polypropylene and 40% of wood fiber. The wood fiber portion consisted of either non-steamed fiber, steamed fiber, and an equal mixture of the two kinds of fiber. Mixing was done using an internal mixer at 180 °C and 60 rpm, and the standard samples were constructed by injection molding. Then, the physical and mechanical characteristics of samples were measured. To consider compatibility between the matrix and reinforcement phase, SEM pictures were taken from the break surface of composite samples. The results showed that the composites’ strengths were affected by steam, as components having steamed fibers had the best mechanical strength and dimensional stability, and also the least water absorption and thickness swelling.
  • Researchpp 8450-8460Lee, H., Lee, Y. M., Heo, Y. M., Lee, H., Hong, J. H., Jang, S., Park, M. S., Lim, Y. W., and Kim, J. J. (2015). "Halo-tolerance of marine-derived fungi and their enzymatic properties," BioRes. 10(4), 8450-8460.AbstractPDF
    Marine environments are unique habitats for microorganisms and represent uninvestigated areas that possess valuable resources. Fungi may also be important because they contribute to marine ecosystems as decomposers. The aims of this study were to investigate the halo-tolerance of marine-derived fungi and their enzymatic properties. Eighteen fungal strains representing 11 different species were used, which included 17 ascomycetes and a zygomycete. The majority were not affected by salinity and showed endo-glucanase (EG) and β-glucosidase (BGL) activities. Interestingly, the cellulolytic enzyme activity derived from Penicillium chrysogenum FU42 increased with salinity. To investigate whether this increase was due to an adaptation or an innate ability of the species, P. chrysogenum KCTC6933, which originated from a terrestrial environment, was used as a control, and its enzymatic properties were compared. Consequently, P. chrysogenum FU42, which was derived from the ocean, showed unique enzymatic properties that might enable the fungus to live in the ocean and contribute to the nutrient cycle in marine ecosystems.
  • Researchpp 8461-8473Svoboda, T., Ruman, D., Gaff, M., Gašparík, M., Miftieva, E., and Dundek, L. (2015). "Bending characteristics of multilayered soft and hardwood materials," BioRes. 10(4), 8461-8473.AbstractPDF
    The influence of selected factors, such as wood species, veneer combinations, and loading cycles, on the bending strength and modulus of elasticity of glued laminated wood was investigated after cyclic loading of 0, 1000, 3000, and 7000 cycles with European beech (Fagus sylvatica (L.)) and Eurasian aspen (Populus tremula (L.)) The laminated woods were created by a combination of densified and non-densified veneers. The 30% densification was carried out by cold rolling. All factors and their interactions had statistically significant influence on the modulus of elasticity. Similarly, the influence of all factors on bending strength was statistically significant. However, the mutual interaction of all factors had no significant effect.
  • Researchpp 8474-8486Yang, M., Xing, J., Liu, Y., Liu, Y., Mu, T., and Zhou, J. (2015). "Formation and characterization of pseudo-lignin microspheres during high-pressure water pretreatment," BioRes. 10(4), 8474-8486.AbstractPDF
    Microspheres were generated after subjecting corn stem rind to high-pressure water pretreatment. These microspheres can be divided into two categories according to their location: free microspheres and adsorbed microspheres. The formation and characterization of both microsphere types were studied. For the free microspheres, the maximum formation was reached at 180 °C; when the temperature was too high (200 °C) or too low (120 °C), no free microspheres were observed. As pretreatment temperature was varied, the morphologies of the free microspheres were different. For the adsorbed microspheres, their formation occurred over a wider temperature range, and their density increased with rising pretreatment temperature. Using Fourier transform infrared spectroscopy, many C=C and C=O bonds were identified on the surface of the free microspheres, indicating the presence of functional groups similar to those of lignin. Compared with untreated corn stem rind, the lignin signal of the residue surface was enhanced, which may be attributable to the increase in adsorbed microsphere quantity.
  • Researchpp 8487-8497Tong, X., Zhang, Z., Chen, X., and Shen, W. (2015). "Analysis of volatile organic compounds in the ambient air of a paper mill - A case study," BioRes. 10(4), 8487-8497.AbstractPDF
    In this work, volatile organic compounds (VOCs) in the ambient air of a secondary fiber paper mill were analyzed. For the sake of studying pollution comprehensively, four sites in the paper mill were analyzed and active sampling methods were used. Desorption was carried out with two solvents, carbon disulfide and dichloromethane. The compositions of VOCs were determined by gas chromatography-mass spectrometry (GC-MS) method. The main identified substances in the four sites were as follows: (1) waste paper sorting room: alkanes, phenols, and esters; (2) papermaking workshop: benzene series, alkanes, ethers, and phenols; (3) vacuum pump outlet: benzene series and phenols; and (4) office area: benzene series and phenols. Two main toxic substances in VOCs, the benzene series and phenols, were detected in the ambient air of the paper mill. The benzene series existed in three places along the main process of the paper mill and even existed in the office area, which was far away from the production line. Additionally, phenols were detected in all sampling locations in the paper mill.
  • Researchpp 8498-8504Tian, S. Q., Wang, Z. L., Wang, Z. Y., Wang, X. W., and Zhao, R. Y. (2015). "Effect of adding corn stalk residue pretreated by laser on immobilized yeast," BioRes. 10(4), 8498-8504.AbstractPDF
    The effect of immobilized yeast on bioethanol production before and after adding laser-pretreated corn stalk residue were investigated. Response surface methodology was used to optimize the conditions of adding residue. An optimum experimental condition was obtained at pH 4.5, 2.08% yeast concentration, and 0.20% corn stalk residue. Under these conditions, adding residue increased the yield of bioethanol from 53.2% to 86.5%, which matched the predicted value. The yield was relatively stable within 28 d, with a downward trend subsequently appearing.
  • Researchpp 8505-8517Yang, Z., Liu, Y., Pang, X., and Li, K. (2015). "Preliminary investigation into the identification of wood species from different locations by near infrared spectroscopy," BioRes. 10(4), 8505-8517.AbstractPDF
    The feasibility of using near-infrared spectroscopy (NIR) to identify wood species was investigated in this study. Case I considers the principal component analysis scores plot of NIR spectra for three wood species. Case II considers whether NIR combined with partial least squares discriminant analyses can be used to identify the three wood species. Three wood species were studied, and each species included five randomly collected wood blocks, 21 samples for each wood block, and 315 total wood samples. In case I, the samples in the PCA analysis were clustered together. In case II, samples in the training set were classified into the correct group, and the accuracy of the test set was up to 90%.
  • Researchpp 8518-8527Oliveira, M. M., Driemeier, C., and Curvelo, A. A. S. (2015). "Changes in nanoscale porosity by wet pressing pulps from sugarcane bagasse," BioRes. 10(4), 8518-8527.AbstractPDF
    Nanoscale porosity is critical for cellulose reactivity and can be detrimentally affected by wet pressing. The present study evaluated how wet pressing reduced the nanoscale porosity of a set of pulps produced from sugarcane bagasse. The pulps were produced using hydrothermal treatments, followed by either 160 °C alkaline (sodium hydroxide) or 190 °C organosolv (ethanol-water) pulping. Pulping times (20, 40, 60, 80, and 100 min) and applied pressures in the pressing step (21, 43, 64, 85, and 107 MPa) were varied, and the resulting samples had their nanoscale porosity characterized using calorimetric thermoporometry. The lowest applied pressure (21 MPa) collapsed a considerable fraction of the nanoscale porosities. Otherwise, when additional pressure (up to 107 MPa) was applied, a much lower reduction in porosity was observed. The findings indicate that nanoscale porosity of pulps can be separated into compressible and incompressible components.
  • Researchpp 8528-8538Kvietková, M. (2015). "The effect of thermal treatment of birch wood on the cutting power of plain milling," BioRes. 10(4), 8528-8538.AbstractPDF
    This article deals with cutting power during the plane milling of thermally treated and untreated silver birch (Betula pendula Roth.) wood. Thermal treatment was carried out at various temperatures of 160, 180, 210, and 240 °C. The cutting power was measured under various milling conditions, such as rake angle of tool (10°, 15°, 20°, 25°, and 30°), cutting speed (20, 40, and 60 m/s), and feed speed (4, 8, and 11 m/min). Thermal treatment had no clear impact on the cutting power. Treated wood at 160 and 180 °C had lower values of cutting power in comparison with untreated wood, while the opposite trend was observed at 210 and 240 °C. The results show that with increasing speed feed, there is an increase in cutting power, while the opposite effect was achieved by changing the cutting speed. The optimum values of cutting power were achieved at a 10° angle and a thermal treatment of 160 °C.
  • Researchpp 8539-8551Danielewicz, D., Surma-Ślusarska, B., Żurek, G., and Martyniak, D. (2015). "Selected grass plants as biomass fuels and raw materials for papermaking. Part I. Calorific value and chemical composition," BioRes. 10(4), 8539-8551.AbstractPDF
    Biomass yield was studied for tall wheatgrass, tall fescue, tall oatgrass, and Miscanthus ´ giganteus per hectare of cultivation, as well as their calorific value and cost of cultivating these biomasses. Chemical analyses were performed on these raw materials to determine their lignin, cellulose, extractives, and ash contents. The analytical results are compared to the chemical constituents found in birch and pine wood. It was found that the grasses examined in this study differed in biomass yield and cost to cultivate (1 ha plot). Tall wheatgrass, tall fescue, tall oatgrass, and Miscanthus leaves had lower levels of lignin compared with wood, but also lower amounts of cellulose. When determining the cellulose content of these biomasses, the amount of inorganic ash that is bound to them must be taken into account.
  • Researchpp 8552-8564Danielewicz, D., Surma-Ślusarska, B., Żurek, G., Martyniak, D., Kmiotek, M., and Dybka, K. (2015). "Selected grass plants as biomass fuels and raw materials for papermaking, Part II. Pulp and paper properties," BioRes. 10(4), 8552-8564.AbstractPDF
    The yield and kappa number of kraft pulps from tall wheatgrass, tall fescue, tall oatgrass, and Miscanthus were determined after pulping with 0.9% active alkali per 1% lignin content in raw materials. Fibre properties and test papers were also studied to evaluate the usefulness of these plants for papermaking. These results were compared with pulps prepared from birch and pine wood. Kraft pulps from the straws of grasses had yields similar to that of pulp from pine wood and lower kappa numbers than pulps from birch and pine wood. The tested pulps exhibited a favourable number of fibres in 1 g of pulp, and they resulted in papers with clearly differentiated properties from very resistant to rupture dense papers with very low air permeability, to less resistant to breaking more bulky papers.
  • Researchpp 8565-8579Wang, F., Chen, H., Ai, M., Zhang, Y., Gao, P., Yang, G., Chen, J., and Huang, F. (2015). "Biomechanical pulping of corn stalk rind with a white rot fungus - Trametes hirsuta - and the use of delignified corn stalk pith as a pulp additive," BioRes. 10(4), 8565-8579.AbstractPDF
    Corn stalk rind (CSR) was treated with Trametes hirsuta lg-9 and then refined into pulp. The biotreatment resulted in loss of paper strength and brightness, but energy consumption during refining (ECR) was reduced. Meanwhile, multiple linear regression was carried out, for which ECR served as the dependent variable, and the yield and infrared relative absorbance intensities at 3414 cm-1 and 1653 cm-1 of the biotreated CSR served as independent variables. Results showed that the determining parameters of the biotreated CSR may be used to predict the ECR. In this work, delignified corn stalk pith (CSP) was added to aspen alkaline hydrogen peroxide mechanical pulp (APMP). The CSP enhanced the strength properties of the aspen APMP and inhibited yellowing. The biomechanical pulping of CSR has the potential to produce a low-cost green pulp, and the delignified CSP can serve as a pulp additive.
  • Reviewpp 8580-8603Salman, S. D., Leman, Z., Sultan, M. T. H., Ishak, M. R., and Cardona, F. (2015). "Kenaf/synthetic and Kevlar®/ cellulosic fiber-reinforced hybrid composites: A review," BioRes. 10(4), 8580-8603.AbstractPDF
    This paper reviews the published and ongoing research work on kenaf/synthetic and Kevlar®/cellulosic fiber-reinforced composite materials. The combination of natural fibers with synthetic fibers in hybrid composites has become increasingly applied in several different fields of technology and engineering. As a result, a better balance between performance and cost is expected to be achieved by 2015, through appropriate material design. This review is intended to provide an outline of the essential outcomes of those hybrid composite materials currently utilized, focusing on processing and mechanical and structural properties.
  • Reviewpp 8604-8656Lehto, J. T., and Alén, R. J. (2015). "Chemical pretreatments of wood chips prior to alkaline pulping - A review of pretreatment alternatives, chemical aspects of the resulting liquors, and pulping outcomes," BioRes. 10(4),8604-8656.AbstractPDF
    The chemical industry is being forced to evaluate new strategies for more effective utilization of renewable feedstocks to diminish the use of fossil resources. In this literature review, the integration of both acidic and alkaline pretreatment phases of hardwood and softwood chips with chemical pulping is discussed. Depending on the pretreatment conditions, high-volume sulfur-free fractions with varying chemical compositions can be produced. In case of acidic pretreatments, the major products include carbohydrates (mono-, oligo-, and polysaccharides), whereas under alkaline (i.e., aqueous NaOH) pretreatment conditions, the sulfur-free fractions of aliphatic carboxylic acids, lignin, and extractives are primarily obtained. All these fractions are potentially interesting groups of compounds and can be used in a number of applications. Finally, the effects of pretreatments on pulping are also considered. Although it is believed that there are important advantages to be gained by integrating this type of renewable raw material-based production, in particular, with kraft pulping, sulfur-free pulping methods such as soda-AQ and oxygen/alkali delignification processes are also briefly discussed.
  • Reviewpp 8657-8749Hubbe, M. A., Gardner, D. J., and Shen, W. (2015). "Contact angles and wettability of cellulosic surfaces: A review of proposed mechanisms and test strategies," BioRes. 10(4), 8657-8749.AbstractPDF
    Contact angle methods are widely used to evaluate the wettability of cellulose-based surfaces and to judge their suitability for different applications. Wettability affects ink receptivity, coating, absorbency, adhesion, and frictional properties. There has been a continuing quest on the part of researchers to quantify the thermodynamic work of adhesion between cellulosic surfaces and various probe liquids and to account for such components of force as the London/van der Waals dispersion force, hydrogen bonding, and acid and base interactions. However, due in part to the rough, porous, and water-swellable nature of cellulosic materials, poor fits between various theories and contact angle data have been observed. Such problems are compounded by inherent weaknesses and challenges of the theoretical approaches that have been employed up to this point. It appears that insufficient consideration has been given to the challenging nature of cellulosic materials from the perspective of attempting to gain accurate information about different contributions to surface free energy. Strong hysteresis effects, with large differences between advancing and receding contact angles, have been overlooked by many researchers in attempting to quantify the work of adhesion. Experimental and conceptual approaches are suggested as potential ways to achieve more reliable and useful results in future wettability studies of cellulosic surfaces.
  • Reviewpp 8750-8769Zhang, A., Shen, J., and Ni, Y. (2015). "Anaerobic digestion for use in the pulp and paper industry and other sectors: An introductory mini review," BioRes. 10(4), 8750-8769.AbstractPDF
    Anaerobic digestion is a well-established biological process for converting biomass in waste streams into a renewable energy source, and it also contributes to the treatment of these waste streams. In this introductory mini-review, some fundamental aspects of anaerobic digestion for use in the pulp and paper industry and other sectors are briefly summarized. The contents include the basics of anaerobic digestion, feedstocks, key process parameters, and typical anaerobic digesters/reactors and their representative manufactures. Fostering the more efficient and widespread commercial use of anaerobic digestion technologies would be a critical strategy to address the issues of energy, the environment, and sustainability.
  • Reviewpp 8770-8794Radics, R., Dasmohapatra, S., and Kelley, S. S. (2015). "Systematic review of bioenergy perception studies," BioRes. 10(4), 8770-8794.AbstractPDF
    This paper presents the results of a structured review of published articles that discuss stakeholders’ perceptions of bioenergy, including both biofuels and biopower. An electronic search process using numerous key terms identified 44 peer-reviewed publications from 2000 to 2013 that focused on stakeholders’ perceptions, understanding, and acceptance of bioenergy. These findings indicate that in the last decade the research community has been more active in publications focused on the societal and public perceptions of the bioenergy industry compared to prior years. Among the reviewed studies, most (84%) are based in the US and Europe, and only a few recent studies have focused on stakeholders in Asia and other parts of the world. This review revealed no standardized methods for evaluation of stakeholder perception, for data collection, or statistical analysis of the data. Among stakeholder groups, the majority of studies focused on the general public or the consumer’s opinion about bioenergy (79% of studies). Overall findings show that the stakeholder groups show low to moderate support for the bioenergy industry. As anticipated, the stakeholder groups had varied views about the opportunities and risks associated with bioenergy industry, and these views varied based on their experiences.
  • Reviewpp 8795-8811Kerekes, R. J. (2015). "Perspectives on high and low consistency refining in mechanical pulp," BioRes. 10(4), 8795-8811.AbstractPDF
    Recent developments in low consistency refining in mechanical pulping have raised questions about the differences between low and high consistency refining. This paper, originally presented to the UBC Energy Reduction in Mechanical Pulping Committee on 10 June 2015 at the PACWEST Conference in Whistler, BC, Canada, discusses the author’s perspectives on these issues as well as on mechanical pulping in general.
  • Reviewpp 8812-8858Eseyin, A. E., Steele, P. H., and Pittman Jr., C. U. (2015). "Current trends in the production and applications of torrefied wood/biomass - A review," BioRes. 10(4), 8812-8858.AbstractPDF
    Trends in the production and applications of torrefied wood/biomass are reviewed in this article. The thermochemical conversion of biomass is a promising technology because biomass is an environmentally friendly fuel that produces substantially lower CO2 emissions compared to fossil fuel. Torrefaction is the thermal treatment of biomass at temperatures from 200 to 300 ˚C in the absence of air or oxygen to liberate water and release volatile organic compounds, primarily through the decomposition of the hemicelluloses. Torrefied biomass has a higher heating value, is more hydrophobic, resists rotting, and has a prolonged storage time. The different torrefaction technologies and reactors are described. An overview of the applications of torrefied biomass, the economic status, and future prospects of torrefaction technology are presented and discussed. Currently, torrefaction demonstration plants have technical problems that have delayed their commercial operation. Torrefaction reactors still require optimization to economically meet end-use requirements and attain product standardization for the market. Several characteristics of torrefaction need to be demonstrated or scaled up for successful commercialization.