NC State
  • Researchpp 126-141Pulkkinen, I., Fiskari, J., and Alopaeus, V. (2009). "The effect of hardwood fiber morphology on the hygroexpansivity of paper," BioRes. 4(1), 126-141.AbstractPDF
    The purpose of this investigation was to study the effect of fiber characteristics, especially fiber wall thickness, on the hygroexpansion behavior of paper due to humidity changes. Five different eucalyptus Kraft pulp samples were studied with an OPTIDIM hygroexpansivity tester. As a reference, birch and acacia were included. In all, seven pulp samples were refined at low consistency (LC), using a Voith Sulzer refiner. Both anisotropic and isotropic sheets were investigated. The sheets were dried under restraint. The results showed that fiber wall thickness is an important factor in controlling the hygroexpansivity of paper through fiber network activation.
  • Researchpp 142-154Chalamcherla, V., Maringanti A., S., Muvva, V. L., Mangamoori, L. N., and Ramireddy, M. R. (2009). "Use of lignocellulolytic mutants of Pleurotus ostreatus in ruminant feed formulations," BioRes. 4(1), 142-154.AbstractPDF
    Two lignolytic mutants (POM1 - U.V. irradiated and POM2 – X ray irradiated) of P. ostreatus wild type (POW) were developed and used in new feed formulations for ruminants. Paddy straw (10 kg) amended with coconut cake, glyricidia leaves, urea (2%), and rice bran (5%) along with mutant forms of P. ostreatus substantially increased the reducing sugars, crude protein, and In Vitro Dry Matter Digestibility (IVDMD), while reducing the lignin contents. Maximum amounts of reducing sugars (555 mg/100 ml) were reported in ration 1 with strain POW in 10 days of incubation period, while a minimum was recorded in POM1 (380 mg / 100 ml) in ration 1 in 30 days of incubation. U.V. irradiated mutant was responsible for accumulation of high crude protein (CP : 42.1 mg / 100 g) in ration 1 after 30 days of incubation. The percent lignin loss was more by mutant forms, and this loss was increased with increased incubation. As a consequence, IVDMD% has been gradually improved and maximized with feed formulations 3 (49.71%) and 1 (47.07%).
  • Researchpp 155-171Nazir, A., Soni, R., Saini, H. S., Manhas, R. K., and Chadha, B. S. (2009). "Regulation of expression of multiple beta-glucosidases of Aspergillus terreus and their purificaiton and characterization," BioRes. 4(1), 155-171.AbstractPDF
    This study reports the regulation and purification of b-glucosidases from a thermotolerant Aspergillus terreus AN1 strain, previously reported for efficient deinking of composite paper waste. The differential expression of four beta-glucosidase isoforms, in response to carbon sources in production medium, was studied by electrophoretically resolving proteins by polyacrylamide gel electro-phoresis analysis (PAGE) and developing zymograms using methylum-belliferyl b-D glucoside as substrate. Three b-glucosidases (bGI, bGII & bGIII) were purified using chromatographic techniques. SDS-PAGE revealed the respective molecular masses of bGI, bGII, and bGIII, as 29, 43, and 98 KDa, and isoelectric point (pI) to be 2.8, 3.7, and 3.0. The b-glucosidases exhibited diverse pH and temperature optima as well as stability. b-Glucosidase I (bGI) specifically recognized pNP-b-glucopyranoside (pNPG) as a substrate, whereas, b-glucosidase II (bGII) and III (bGIII) also showed activities against cellobiose and salicin. In contrast to bGII and bGIII, the activity of bGI was positively influenced in the presence of hexoses/pentoses and alcohols. Km and Vmax for hydrolysis of pNPG by bGI, bGII, andbGIII were found to be 14.2 mM and 166.9 µmol -1mg protein -1, 4.37 mM, and 34.7 µmol -1mg proteins -1, and 11.1 mM and 378.7µ mol -1 mg protein -1, respectively.
  • Researchpp 172-193Rutkowska, E. W., Wollboldt, P., Zuckerstätter, G., Weber, H. K., and Sixta, H. (2009). "Characterization of structural changes in lignin during continuous batch kraft cooking of Eucalyptus globulus," BioRes. 4(1), 172-193.AbstractPDF
    Eucalyptus globulus wood originating from plantations in Uruguay was subjected to continuous batch kraft cooking (CBC), applying mill-like conditions. Pulp samples were taken at different stages of CBC cooking being representative for all three cooking phases. The residual lignin was successfully isolated in a reasonable yield by a new method, the dissolved wood lignin (DWL) protocol, which is based on the total dissolution of ball milled wood and pulp samples in dimethylsulfoxide and N-methylimidazole (DMSO/NMI) followed by precipitation in dioxane/ water to separate lignin and carbohydrate fractions. For comparative reasons, the lignin was also isolated by a conventional mild acidolysis (AL) method. Extensive structural lignin characterization using 1D and 2D NMR revealed that the DWL protocol allows the isolation of less altered lignin than the AL method. During bulk and residual delignification, the S/G ratio of lignin remaining in the fibers continuously decreased, while the content of b-O-4 units and phenolic OH groups remained almost unaffected, suggesting that the CBC process permits enhanced delignification efficiency and good bleachability.
  • Researchpp 194-204Tarmian, A., and Azadfallah, M. (2009). "Variation of cell features and chemical composition in spruce consisting of opposite, normal, and compression wood," BioRes. 4(1), 194-204.AbstractPDF
    A number of important anatomical features and chemical composition in opposite, normal, and compression wood of Norway spruce (Picea abies) were evaluated to optimally utilize spruce logs containing compression wood. A comparison of axial tracheid and ray cell features in the opposite, normal, and compression wood was provided. Lignin, cellulose, acetone-soluble, and water-soluble extractive contents of the woods were also determined. Results revealed a major variation in the anatomical and chemical characteristics of the woods. Compression wood showed extremely different microscopic features, and chemical composition compared to normal and opposite wood. In most of features investigated in the present study, normal wood occupied a transitional position between opposite and compression wood.
  • Researchpp 205-213Uraki, Y., Tamai, Y., Ogawa, M., Gaman, S., and Tokura, S. (2009). "Preparation of activated carbon from peat," BioRes. 4(1), 205-213.AbstractPDF
    Peat with an approximate 60% carbon content collected in the suburbs of Palangka Raya, Indonesia, was carbonized, followed by activation with steam in an electric furnace. The resultant activated carbon (AC) had ca. 900 m2/g of BET surface area and 1000 mg/g of iodine adsorption. This performance implies that this AC can be used as an adsorbent for environmental purification. We had a carbonizing furnace manufactured in Palangka Raya, which did not require electric power. Some AC having 350 mg/g of iodine adsorption was obtained by using this furnace. Although the adsorption ability was much lower than that of commercially available AC, the AC achieved significant decoloration and decrease in chemical oxygen demand of polluted river water. Thus, this article demonstrated the potential of tropical peat soil as a source of AC.
  • Researchpp 214-233Ekhtera, M. H., Azadfallah, M., Bahrami, M., and Mohammadi-Rovshandeh, J. (2009). "Comparative study of pulp and paper properties of canola stalks prepared by using dimethyl formamide or diethylene glycol," BioRes. 4(1), 214-233.AbstractPDF
    Comparision between pulping of canola stalks with dimethyl formamide and diethylene glycol was studied in order to investigate the effects of cooking temperature (190˚C, 210˚C, and 230˚C), cooking time (120 min, 150 min, and 180 min) and dimethyl formamide or diethylene glycol (50%, 60%, and 70%) on the properties of pulp and paper. SCAN viscosity was applied to estimate the extent of cellulose degradation. Responses of pulp and handsheet properties to the process were analyzed using statistical software (MINITAB 15). The results showed that DMF pulp of canola was better than DEG pulp of Canola under the same conditions of cooking and organosolv ratio. In DMF pulping and DEG pulping, cooking temperature is a significant factor affecting paper properties. Analysis of results revealed that DMF pulp canola obtained at 230 °C, 180 min, and 70% DMF had a low kappa number (25) , indicating that the desired properties of the final product dictated the optimized pulping conditions.
  • Researchpp 234-244Yokota, S., Matsuo, K., Kitaoka, T., and Wariishi, H. (2009). "Retention and paper-strength characteristics of anionic polyacrylamides conjugated with carbohydrate-binding modules," BioRes. 4(1), 234-244.AbstractPDF
    The retention behavior of polymers having the specific affinities of glyco-hydrolases for pulp fibers was investigated with regard to paper-strength enhancement in contaminated papermaking systems. Carbohydrate-binding modules (CBMs) of cellulases derived from Trichoderma viride and T. reesei, and of xylanase from Thermomyces lanuginosus, were obtained by site-directed digestion with papain, then introduced into anionic polyacrylamide (A-PAM) via a peptide condensation reaction. Three types of CBM-conjugated A-PAMs (CBM-A-PAMs) displayed different retention behavior, depending on the kind of pulp substrates, i.e. hardwood and softwood fibers. The CBM-A-PAM from T. viride demonstrated good additive retention for hardwood pulp fibers, resulting in high tensile strength of paper sheets, even under contaminated conditions in the presence of Ca2+ ions and ligninsulfonate. The CBM-A-PAM from T. reesei showed better performance for softwood than for hardwood sheets. The xylanase CBM-A-PAM was preferentially retained on hardwood fibers in which hemicelluloses might be present. Such an additive retention system, with inherent affinities of enzymes for pulp fibers, is expected to expand the application range of CBM-polymers in practical wet-end processes.
  • Researchpp 245-256Enayati, A. A., Hamzeh, Y., Mirshokraie, S. A., and Molaii, M. (2009). "Papermaking potential of canola stalks," BioRes. 4(1), 245-256.AbstractPDF
    A fundamental study was carried out to explore the properties of canola stalks with regards to pulp and paper production. In this study the morphological properties, chemical composition, and soda pulping properties of canola stalks were investigated. The mean values of length, diameter, and cell wall thickness of canola stalks fibers were measured as 1.17 mm, 23.02 mm, and 5.26 mm, respectively. The morphological properties analysis indicated that despite the thicker cell wall, the morphological properties of canola stalks fibers were comparable to those of non-woods and hardwoods fibers. The holocelluloses, alpha-cellulose, lignin, and ash contents of canola stalks were determined to be 73.6, 42.0, 17.3, and 8.2 wt%, respectively. The hot water and dilute alkali extractives of canola stalks were determined as 18 and 46.1 wt%. In comparison to most other non-wood papermaking raw materials, soda pulping of canola stalks required higher chemical charge and cooking time. Soda pulping of canola stalks gave a low yield bleachable grade pulp. The strength properties of bleached canola stalks soda pulp appeared to be similar to those of common non-wood papermaking resources. The overall results showed that canola has a promising potential to be used in pulp and paper production.
  • Researchpp 257-267Pandey, K. K., Jayashree, and Nagaveni, H. C. (2009). "Study of dimensional stability, decay resistance, and light stability of phenylisothiocyanate modified rubberwood," BioRes. 4(1), 257-267.AbstractPDF
    Rubber wood (Hevea brasiliensis) was esterfied with phenylisothiocya-nate, and dimensional stability, decay resistance, and photo stability of the modified wood was assessed. The chemically modified wood was characterized by FTIR and CP/MAS 13C NMR spectroscopy. Unmodified and modified samples were exposed to a brown rot (Polyporus meliae) and a white rot (Coriolus versicolor) fungus for 12 weeks. Modified wood samples exhibited good dimensional stability and were very resistant to decay. However, phenylisothiocyanate modification of wood was not effective in decreasing photo-yellowing.