NC State
  • Researchpp 6643-6660Ha, S., Jung, J., Park, J., Yu, C., Park, J., and Yang, J. (2021). "Effects of pine (Pinus densiflora) sawdust on cordycepin yield from medicinal fungus Cordyceps militaris in submerged culture," BioResources 16(4), 6643-6660.AbstractArticlePDF

    Cordycepin (3′-deoxyadenosine) is a nucleoside analog that exhibits a broad spectrum of biological activity. The effects of different tree sawdust on cordycepin as bioactive substances for mycelium growth were investigated. Pine sawdust was essential for increasing cordycepin content. Furthermore, a 1% NaOH-pretreated pine sawdust produced the highest cordycepin yield. The cordycepin yield of mycelium in submerged culture was significantly increased when the particle size was 100-mesh and the weight was 20 g/L of 1% NaOH-pretreated pine sawdust, with an increase of up to 38% compared to the control (only sabouraud dextrose broth (SDB)). The results demonstrated the effects of different tree sawdust on the biosynthesis of cordycepin as bioactive substances and that replacing traditional medium (SDB medium) with 1% NaOH-pretreated pine sawdust can increase the yield of cordycepin. After optimization of cordycepin production from Cordyceps militaris cultivated in medium containing 1% NaOH-pretreated pine sawdust using RSM (response surface methodology) BBD (Box-Behnken design) in its canonical form, the optimum combination was: particle size, 113.7-mesh; input weight, 11.9 g/L; and incubation time, 67.8 h. The model predicted a maximum yield of 922.6 μg/mL for cordycepin.

  • Brief Communicationpp 6661-6668Ferro, F. S., Arroyo, F. N., Rodrigues, E. F. C., Fraga, I. F., Almeida, J. P. B., Ruthes, H. C., Aquino, V. B. M., Morales E. A. M., de Moraes, M. H. M., Lahr, F. A. R., and Christoforo, A. L. (2021). "Investigation of pore size distribution by mercury intrusion porosimetry (MIP) technique applied on different OSB panels," BioResources 16(4), 6661-6668.  AbstractArticlePDF

    Mercury intrusion porosimetry (MIP) is a technique used to characterize the pore size distribution and resin penetration in lignocellulosic materials, such as oriented strand board specimens (OSB), a multilayer panel utilized in structural applications. The method is based on the isostatic injection, under very high pressure, of a non-wetting fluid (mercury) into the porous material to determine parameters such as pore size distribution and percentage of porosity of the specimens. In this study, five different OSB were analyzed; they contained different wood species, resin type, and resin content. The panels manufactured with castor oil polyurethane resin showed porosity values in the range of 54.7 and 27.8%. This was a promising result compared with those obtained for panels made with phenolic resins, which are currently commercialized in Brazil.

  • Researchpp 6669-6683Zhang, Y., Liu, Y., Liu, M., and Li, C. (2021). "Preparation and performance study of modified silica sol/phenolic resin," BioResources 16(4), 6669-6683.AbstractArticlePDF

    This study used silica sol, phenol, formaldehyde, etc. as raw materials to prepare silica sol/phenolic resin based on in-situ polymerization. The influence of silica sol content on the viscosity, solid content, and other properties of the composite resin were discussed. The structure and performance of the product were characterized and tested via laser particle size analyzer, infrared spectrum analyzer, thermogravimetric (TG) analyzer, and rheometer. The results show that the viscosity of the composite resin increased with increased silica sol content, and the solid content and the free formaldehyde content exhibited the opposite trend. The laser particle size analysis revealed that when the amount of silica sol was 40%, the particle size distribution of the composite resin was relatively uniform. Fourier transform infrared analysis illustrated a new chemical bond of Si-O-C formed between silica sol and phenolic resin. TG analysis showed that when the amount of modified silica sol was added at a 40% level, the decomposition temperature of composite resin (10% weight loss) increased from 294.8 to 324.4 °C, and the residual amount increased from 55.2% to 60.2%; rheological analysis revealed that when the content of silica sol was 40%, it had better flow properties, creating conditions for the composite resin to penetrate the wood.

  • Researchpp 6684-6705Elloumi, I., Hernandez, R. E., Cáceres, C. B., and Blais, C. (2021). "Effects of temperature and moisture content of logs on size distribution of black spruce chips produced by a chipper-canter at two cutting widths," BioResources 16(4), 6684-6705.AbstractArticlePDF

    Four matched groups of black spruce logs were processed with a chipper-canter at temperatures of 20, 0, -10, and -20 °C. Each log was transformed at two moisture contents (MC, green and air-dried) using two cutting widths (CW, 12.7 and 25.4 mm). Mean MC for each CW was assessed from a sample of the obtained chips. Knot characteristics were measured on the cant surfaces after log processing. Chip size was assessed by thickness (Domtar classifier) and width/length (Williams classifier). The results showed that the chip size was significantly affected by the CW and temperature, and in a lesser degree by the chip MC. The weighted mean chip thickness (WCT) increased with the CW. As temperature decreased below 0 °C, WCT and accepts decreased, while proportions of fines and pin chips increased. Chips obtained from green logs were thinner compared to air-dried logs when processed at the coldest temperature (minus 20 °C). The number and size of knots had an important impact on chip size, particularly on WCT. Multiple regressions were developed to predict WCT. Results showed the potential benefits of measuring log temperature and knot features to reduce chip thickness variation during fragmentation and thus improving chip size uniformity.

  • Reviewpp ##-##Rudak, O., Barcík, Š., Rudak, P., Chayeuski, V., and Koleda, P. (2021). "Densification of wood – Chemical and structural changes due to ultrasonic and mechanical treatment," BioResources, 16(4), Page numbers to be added.AbstractArticlePDF

    This paper presents the state of the art of wood surface densification method by pressing with ultrasound. The properties of ultrasound and its effects on the structure and properties of wood, as well as ultrasound-induced chemical changes in wood material, are described. The following research results were analyzed: the effects of acoustic cavitation in wood material, plasticization of wood lignin by processing with ultrasound, the influence of ultrasound on the wood anatomical structure, the combined effect of ultrasound and wood pressing, and the sterilization of wood using ultrasonic action. Ultrasound causes conversion of lignin from glassy into a quasi-rubbery state, which facilitates compaction of the workpiece surface. Additionally, under ultrasound, growth and collapse of gas bubbles (cavitation phenomena) occur within a liquid medium of wooden substance accompanied by high local temperatures and production of chemically active radicals. This contributes to the destruction of the former and the formation of new bonds in the wood substance, which is important for increasing the stability of the workpiece size after densification. The conclusions made about the ultrasound can be effectively used for the wood plasticization and about prospects of joint use of wood pressing and ultrasound for wood surface densification.

  • Researchpp 6706-6722An, Q., Shi, W., He, Y., Hao, W., Ma, K., Chen, X., Yang, J., Yan, X., Bian, L., Li, C., and Han, M. (2021). "Evaluation of the capacity of laccase secretion of four novel isolated white-rot fungal strains in submerged fermentation with lignocellulosic biomass," BioResources, 16(4), 6706-6722.AbstractArticlePDF

    The capacity of novel isolated white-rot fungi secreting laccase was evaluated for various kinds of lignocellulosic biomass in submerged fermentation. The laccase secreted by Neofomitella fumosipora Han 386 and Pleurotus pulmonarius Han 527 was significantly faster than that by Coriolopsis trogii Han 751 and Coriolopsis sanguinaria An 282. Maximum laccase from N. fumosipora Han 386 on the four kinds of lignocellulosic biomass tested appeared on the first day. This phenomenon indicated that N. fumosipora Han 386 secreted laccase rapidly compared with other tested strains in this study and showed the superiority in the rate of secreting laccase. Based on the maximum laccase activity, the ability of secreting laccase of C. sanguinaria An 282 was superior to other tested novel isolated strains. On the whole, N. fumosipora Han 386 and P. pulmonarius Han 527 preferred Toona sinensis to produce laccase, C. trogii Han 751 preferred to produce laccase on Populus beijingensis, and C. sanguinaria An 282 grown on Sorghum straw was more suitable for secreting laccase. The results will be helpful for developing bioprocesses using various kinds of lignocellulosic biomass for lignocellulolytic enzyme production and enlarging the number of laccase producing strains for industrial application.

  • Researchpp 6723-6736Zhao, W., Zhou, C.-Y., Zhang, J., and Wang, D.-Q. (2021). "High-solids anaerobic digestion of cassava pulp in semi-continuous bioreactors," BioResources, 16(4), 6723-6736.AbstractArticlePDF

    The effects of two total solids contents (TS) and two inocula were studied for the semi-continuous high-solids anaerobic digestion (HS-AD) of cassava pulp under mesophilic conditions (35 ± 2 °C). In the 1.0-L bioreactors, two TS of 15% and 20% with digestate as a sole inoculum were chosen to run the HS-AD, and two inocula (the digestate from the AD of cassava pulp and sewage sludge) were used separately under TS 20%. All treatments were carried out at the organic matter loading rates (OLRs) of from 3.0 to 10.0 kg volatile solids (VS)/(m3·d), with each phase of 6 days followed by two 3-days phases of no feeding and then low OLR of 6.5 kg VS/(m3·d). Compared with TS 15%, the bioreactors of TS 20% with the digestate had a higher buffering capability to alleviate the rapid acidification and a higher level of the specific methane yields (SMYs) of from 0.212 to 0.233 m3/(kgVSadded) at the OLRs of 4.0 to 6.5 kgVS/(m3·d), while TS 15% obtained the highest SMY of from 0.152 to 0.182 m3/(kgVSadded) at the OLR of 4.0, 6.5, and 8.0 kgVS/(m3·d). In contrast, sewage sludge did not restrain the rapid acidification and only yielded quite small SMYs under TS 20%.

  • Researchpp 6737-6749Trnka, J., Holubcik, M., Cajova Kantova, N., and Jandacka, J. (2021). "Energy performance of a rotary burner using pellets prepared from various alternative biomass residues," BioResources 16(4), 6737-6749.AbstractArticlePDF

    Alternative biomass makes up a considerable portion of the waste from biomass processing in forestry and agriculture. The aim of this work was to create pellets from several sources of alternative biomass, e.g., lawn clippings, corn husks, linden leaves, and pine needles, which were compared to pure wood pellets. Analysis of the fuel properties focused on their chemical composition, thermogravimetric analysis, calorific values, and ash melting temperatures. The power and emission parameters of the fuels were determined via an automatic pellet boiler. The primary issues in the combustion of the alternative biomass types were low calorific values, increased emissions, high ash contents, and low ash melting temperatures. The two primary options for solving these problems are the production of fuel mixtures with wood or the use of new combustion technologies. This work also dealt with the combustion of alternative biomass via a rotary burner. The results showed an increase in the ash content of the alternative biomass, which also led to the burner occasionally going out due to clogging with the accumulation of ash and sintering. Based on the results, only pellets from pine needles and corn husks can be recommended for further use.

  • Researchpp 6750-6757Fraga, I. F., Moraes, M. H. M., Menezes, I. S., Arroyo, F. N., Almeida, J. P. B., Rodrigues, E. F. C., Mascarenhas, F. R., Aquino, V. B. M., Silva, S. A. M., Lahr, F. A. R., Júnior, W. M. P., and Christoforo, A. L. (2021). "Influence of roof slope on timber consumption in plane trusses design," BioResources 16(4), 6750-6757.AbstractArticlePDF

    The growing world consumption of wood in civil construction is evident, especially in structural roofing systems. Despite being from a renewable source, its rational and intelligent use is of vital importance in the execution of structural designs. Because it is a system that is recognized worldwide in the design of trussing roof structures, there are several empirical assumptions for structural calculation. To reduce timber consumption, some tile manufacturers suggest a 10% (6°) slope between chords. However, after simulations of 11 slopes with angles from 5° to 15°, the timber consumption was inversely proportional to the slope, reaching a 90% difference between extreme angles. The method used to obtain the results was software designed according to the routines prescribed by the new draft standard of ABNT NBR 7190 (2021). Considering a prefabricated truss with 5 cm thickness sections, the design criterion was that of minimum height, increasing by 0.10 cm until all checks were satisfied. Finally, the minimum angle after which no strengthening is required on the bars was 10°.

  • Researchpp 6758-6765Soares, L., Fraga, I., Paula, L., Arroyo, F., Ruthes, H., Aquino, V., Molina, J., Panzera, T., Branco, L., Chahud, E., Christoforo, A., and Lahr, F. (2021). "Influence of moisture content on physical and mechanical properties of Cedrelinga catenaeformis wood," BioResources 16(4), 6758-6765.AbstractArticlePDF

    This study aimed to investigate the influence of moisture content variation on 12 mechanical properties of the Cedrelinga catenaeformis species. Of the 12 properties, four were significantly affected (based on analysis of variance at 5% significance level), and the compression and shear strengths in the direction parallel to the fibers exhibited the greatest difference in values from the saturated moisture condition of up to 12% (approximately 34% increase). Toughness exhibited a behavior different from that predicted by the normative equation, in which increase in moisture content implied increase (approximately 59%) of the property studied. Because a good part of the properties was not significantly affected and Brazilian standard ABNT NBR 7190 (1997) considers expressions that lead to a considerable increase in mechanical properties with the reduction of moisture content, this approach was unfavorable to the safety of the project, motivating the development of other studies to collaborate in revisions of this normative document.