Volume 7 Issue 4

The effect of commercial heat treatment on physical and mechanical properties of compression wood (CW) and opposite wood (OW) of black pine (Pinus nigra Arnold) was investigated. Black pine logs containing CW were cut parallel to the pith and separated into CW and OW sections. A commercial heat treatment process was applied to pine lumber at 180 and 210 ºC for 3 hours. Water absorption (WA), contact angle (CA), swelling, modulus of rupture (MOR), modulus of elasticity (MOE), and impact bending strength (IBS) were measured. The results showed that heat treatment decreased water absorption and swelling of the CW and OW of black pine. Heat treatment at 210 °C temperature decreased the longitudinal swelling of CW by 51.4%. Higher immersion time lowered the effect of heat treatment on the WA values. The CA values of the CW and OW increased due to heat treatment. Heat treatment reduced the MOR, MOE, and IBS values. The results indicated that MOR, MOE, and CA values were highly affected in the CW; on the other hand, the IBS value was highly affected in the OW by heat treatment compared to control groups. The results indicate that heat-stabilized CW can be used more widely and effectively in the forest products industry.

Most research on the upgrading of bio-oil by cracking has been done under atmospheric pressure, which results in a catalyst coke yield as high as 20 wt%. In this paper, pressurized cracking, as well as co-cracking with methanol proved to be an effective solution for relieving catalyst deactivation. HZSM-5 catalyst was found to deactivate rapidly in the cracking process of pure ketones. However, when methanol was used as the co-cracking substance for ketones under 2 MPa, ketones reached a full conversion of 100 % without obvious catalyst deactivation. The highest selectivity of bio-gasoline phase from co-cracking of ketones and methanol reached a value of 31.6%, in which liquid hydrocarbons had a relative content of 97.2%. The co-cracking of hydroxypropanone and methanol had lower bio-gasoline phase selectivity but better oil phase quality (liquid hydrocarbons selectivity up to 99%) than those of cyclopentanone and methanol. Based on the experimental results, the promotion mechanism of methanol on cracking of ketones in bio-oil was illustrated by a co-cracking mechanism model.

The main objective of this research was to study the feasibility of incorporating organosolv semi-chemical triticale fibers as the reinforcing element in recycled high density polyethylene (HDPE). In the first step, triticale fibers were characterized in terms of chemical composition and compared with other biomass species (wheat, rye, softwood, and hardwood). Then, organosolv semi-chemical triticale fibers were prepared by the ethanolamine process. These fibers were characterized in terms of its yield, kappa number, fiber length/diameter ratio, fines, and viscosity; the obtained results were compared with those of eucalypt kraft pulp. In the second step, the prepared fibers were examined as a reinforcing element for recycled HDPE composites. Coupled and non-coupled HDPE composites were prepared and tested for tensile properties. Results showed that with the addition of the coupling agent maleated polyethylene (MAPE), the tensile properties of composites were significantly improved, as compared to non-coupled samples and the plain matrix. Furthermore, the influence of MAPE on the interfacial shear strength (IFSS) was studied. The contributions of both fibers and matrix to the composite strength were also studied. This was possible by the use of a numerical iterative method based on the Bowyer-Bader and Kelly-Tyson equations.

The moisture dependence of different mechanical properties of bamboo has not been fully understood. In this work, the longitudinal tensile modulus, bending modulus, and compressive and shearing strength parallel to the grain were determined for bamboo of ages 0.5, 1.5, 2.5, and 4.5 years under different moisture contents (MC) to elucidate the sensitivity of different mechanical properties of bamboo to MC change. The results showed that the four mechanical properties of bamboo respond differently to MC changes. Compressive and shearing strength parallel to the grain were most sensitive to MC changes, followed by longitudinal tensile modulus, then bending modulus. This can be partially explained by the different responses of the three main components in the plant cell wall to MC change. For tensile modulus and bending modulus, the effect of bamboo age on the sensitivity to MC change was insignificant, while young bamboo (0.5 years old) was more sensitive to MC changes for shear strength and less sensitive for compression strength than older bamboo.

During the most recent decades the U.S. wood products and furniture manufacturing industries have been greatly affected by economic cycles, rising production and transportation costs, changing buyer habits, and, arguably most powerfully, increasing global competition. However, theories exist stating that the use of management systems, such as Lean, allows companies to be more successful despite operating in a more challenging environment. To assess Virginia’s wood products and furniture manufacturing industry’s Lean awareness and Lean implementation efforts, a census survey was conducted. Findings indicate that a majority of Virginia’s wood products and furniture manufacturing industry have heard about Lean (72 percent), but a relatively low number of respondents are aware of the details of Lean. Forty-seven percent of respondents indicated to have implemented Lean. However, the extent of Lean implementation varied widely, with a majority having implemented less than half of all 29 Lean elements inquired about in this survey. Business results from implementing Lean and the need for external Lean implementation support are presented in the second manuscript of this two-manuscript series.

Rhizomucor tauricus, an industrial fungus, was immobilized in sodium alginate and used as adsorbent for the removal of nickel from aqueous solutions. The biosorption capacity of Ni(II) was found to be 394 mg/g of immobilized biomass. It was observed that an increase in pH from 3 to 6 increased the percent adsorption, and an increase in liquid-to-solid ratio from 2 to 10 increased the metal uptake. The percent adsorption was increased when increasing the initial metal concentration from 25 to 100 mg/L. The equilibrium biosorption data was evaluated by Langmuir, Freundlich, and Langmuir-Freundlich (L-R) isotherm models, and was best described by the Langmuir and Freundlich isotherms. FTIR analysis revealed that –NH (bending), C–H (stretching), C=O (stretching), and –OH functional groups were mainly responsible for Ni(II) biosorption. Thus, this study demonstrated that the immobilized Rhizomucor tauricus biomass could be used as an adsorbent for the treatment of Ni(II) from aqueous solution.

This two-part publication about Lean practices by Viriginia’s wood products and furniture manufacturing industries reports results from researching the awareness, the implementation status, the business results, and the need for external implementation support of Virginian companies. This second manuscript focuses on business results and the need for external implementation support. Except for “sales per employee,” where less than half of respondents reported an improvement due to the implementation of Lean in their operation, a majority of respondents indicated improved business results for “lead time,” “on-time delivery,” “inventory turnover,” and “cost per unit.” With respect to the need for external Lean implementation support, only 23 percent of respondents answered in the affirmative. “Training management,” “training shop floor employees,” and “implementing [Lean] with extensive employee involvement” were, with 67, 58, and 48 percent frequencies, the most often named forms of Lean implementation support requested. Results from this study seem to indicate an opportunity to support the well-being of Virginia’s wood products and furniture manufacturing industries through improved communication of the benefits of Lean and offering specific types of training to companies.

Activated carbon was prepared from sugarcane bagasse with phosphoric acid activation by a mechanochemical process. The effects of milling time on adsorption properties and pore structure of activated carbon were evaluated. The results showed that phosphoric acid activation was assisted by the mechanochemical process, which can reduce the processing time and improve the adsorption performance of the prepared activated carbon. The iodine number, the methylene blue adsorption value, and the specific surface area of the prepared activated carbons were improved from 647.94 mg/g, 150 mg/g and 1075.21 m2/g to 889.37 mg/g, 177 mg/g, and 1254.52 m2/g, respectively. Compared with conventional phosphoric acid activation, the activated carbon produced by the mechanochemical process achieved the advantages of shorter processing time, greater adsorption capacity, and higher adsorbed amounts of iodine, methylene blue, and nitrogen.

Heat treatment can be used to improve the physical properties and durability of wood. The results achieved by heat treatment can be affected significantly by various factors. Juvenile wood and mature wood from the same trunk have different properties, and the effects of heat treatment on their physical properties have not been well defined. Thus, a study to determine the differences in the physical properties of juvenile wood and mature wood of E. grandis after heat treatment was conducted. Samples of both types of wood were treated at temperatures of 120, 150, and 180 ºC for durations of 4, 6, and 8 h. The results showed that the physical properties of juvenile and mature wood, e.g., swelling, moisture content, and fiber saturation point, did not decrease to the same extent. Mass loss of mature wood was higher than that of juvenile wood. Generally, percentage decreases of volumetric swelling, moisture content, and fiber saturation point of juvenile wood were more affected than those of mature wood.

In this work, the effect of oil heat treatment (OHT) on the swelling properties and changes in the rate of moisture uptake of poplar wood (Populus × euramericana cv. Pannónia) were investigated. Eighteen different treatments (combinations of three vegetable oils, two temperatures, and three durations) were studied. The results showed that OHT decreases the equilibrium moisture content (EMC) and the swelling of poplar wood. The degree of swelling and the EMC are influenced by both the duration and temperature of treatment. With an increase in duration and temperature, the EMC decreased. Consequently, the anti-swelling efficiency (ASE) increased. OHT wood adsorbs less moisture than natural wood, but it reaches a maximum – EMC at the momentary climate – at the same time under all the investigated treatments. The moisture uptake is fastest in the beginning and thereafter it slows significantly. Decreasing the moisture uptake by OHT wood is due to the decreasing of its water storage capacity.