NC State
  • Researchpp 6262-6276Chen, H., Wang, Y., Qiu, J., Song, J., Wang, J., Liu, M., Wo, Q., Jiang, L., and Yang, T. (2022). "Properties and application of kraft pulp prepared from waste bamboo powder," BioResources 17(4), 6262-6276.AbstractArticlePDF

    As a by-product of bamboo processing, bamboo powder is incinerated or buried due to its ineffective utilization, which contributes to pollution. The large amount of waste bamboo powder generated during the processing of bamboo products cannot be effectively utilized. Meanwhile, multiple recycling leads to the loss of fiber quality of corrugated cardboard (OCC) pulp, reducing the mechanical properties of paper. In an effort to obtain high value from waste bamboo powder, this study pulped it using the kraft process. Scanning electron microscope (SEM) observations showed that the surface of bamboo fiber had more cracks, which made bamboo fiber have better air permeability. The permeability of bamboo paper was 146% that of the OCC. X-ray diffraction (XRD) analysis showed that the crystallinity of bamboo pulp was 133% that of the OCC pulp. The results of physical testing of paper showed that the tensile strength of bamboo paper was 116% that of the OCC. The tear strength of bamboo paper was 61.7% that of the OCC, and the bursting strength of bamboo paper was 59.1% that of the OCC. Based on the above results, bamboo powder can be used as raw material for making OCC pulp.

  • Researchpp 6277-6292Li, M., Kang, Y., Nguyen, V., Gao, X., Zhang, L., Wang, J., Zhou, X., and Ma, G. (2022). "3D reconstruction of the tree internal decay based on radar waves," BioResources 17(4), 6277-6292.AbstractArticlePDF

    TRU Tree Radar is a new tool for the non-destructive testing of trees. In this work, two-dimensional images of the internal defect cross-section of a tree were reconstructed to provide a theoretical basis for accurately judging the shape and position of the internal decay, rationally using wood, and improving the utilization rate of wood. Two-dimensional images of different height defect sequences of tree trunk obtained by TRU tree radar were preprocessed and interpolated. Finally, the three-dimensional reconstruction of internal defects of tree trunk was realized by the surface rendering method and volume rendering method under the Matlab environment. The surface rendering displayed the rough 3D model quickly and effectively. However, the important internal information was incomplete, and the reconstructed model was not intuitive. Volume rendering was used to process each voxel in the data set, so as to describe the physical reality of the internal defects of the tree relatively accurately. An algorithm was proposed to improve the visualization level of internal defects, which can enhance the understanding of the three-dimensional image.

  • Researchpp 6293-6302Song, Y., Han, Y., Wang, L., Zhang, W., Chen, T., Meng, J., Xin, M., Liu, Y., and Shan, R. (2022). "Parameters optimization for compressing a mixture of decomposed rice straw and biochar into a seedling-raising mat," BioResources 17(4), 6293-6302.AbstractArticlePDF

    Transplanting is the prime growing pattern for rice production, and seedling raising is an essential step of the process. However, the massive soil source and the complicated treatments needed for seedling raising are major issues. This study explored the possibility of using compressed-decomposed rice straw and biochar from rice husk into a seedling-raising mat, to replace the soil and simplify the seeding process. A quadratic rotation-orthogonal combination experiment was conducted to investigate the effect of moisture content, pressure, and residence time on the formation of seedling-raising mat. The regression models between the compressing indicators and the process factors were established. The results showed that the following factors had significant effect on bending strength of the formed mat (P < 0.01): the pressure and residence time have extreme effects on dimensional stability (P < 0.01); but the influence of moisture content was insignificant (P > 0.05). The process parameters for compression were optimized and verified using Design-Expert software 8.0.6. The optimized parameters were moisture content of 33%, pressure of 23.0 MPa, and residence time of 61 s. The prediction error is less than 6% under this condition. The results may provide a reference for biomass seedling-raising mat compression.

  • Researchpp 6303-6324Chen, J., Beatson, R. P., Tam, K., Bicho, P., and Trajano, H. L. (2022). "Kraft pulping of softwood chips with mild hot water pre-hydrolysis to understand the effects of wood chip thickness," BioResources 17(4), 6303-6324.AbstractArticlePDF

    Hemicelluloses consume alkali during kraft pulping and dissolve in the black liquor as a low energy fuel. Acidic pre-hydrolysis of softwood chips removes hemicelluloses but preserves cellulose content prior to pulping. This study compared mild pre-hydrolysis (140 °C) kraft pulping with conventional kraft pulping of commercial softwood chips at two H-factors for wood chips with thickness ranging from less than 2 mm to over 6 mm. The chip thickness less than 2 mm increased hemicelluloses oligomer yield and showed little influence on pulp fiber yield. However, the kraft pulp fiber length decreased 5.6%. Kappa number and fiber reject increased dramatically when chip thickness was greater than 6 mm. The detailed compositional analysis of kraft pulp and fiber quality analysis indicate that pre-hydrolysis followed by kraft pulping enhanced delignification with limited reduction of fiber length and width, and increased kinks. Strategic considerations for the integration of pre-hydrolysis into kraft pulping for future biorefineries were outlined.

  • Researchpp 6325-6340Gao, Y., Hu, X., Tong, S., Kan, J., Wang, Y., and Kang, F. (2022). "Multi-objective optimization of peak cutting force and cutting energy consumption in cutting of Caragana korshinskii branches," BioResources 17(4), 6325-6340.AbstractArticlePDF

    Caragana korshinskii (C.K.) flat stubble residue is an abundant biomass energy source in China. Because branch cutting is closely related to the harvesting of forest biomass, it is practical for forestry production and ecological development to investigate the effects of cutting parameters on the peak cutting force and cutting energy consumption of C.K. branches. In this study, the effect of cutting parameters on the peak cutting force and cutting power consumption of branches was investigated by single-factor and multi-factor tests using an independently developed reciprocating cutting test bench, and an optimization model was established. The interaction term of average cutting speed and tool cutting edge inclination angle significantly affected the peak cutting force, while the interaction term of cutting clearance and wedge angle had a significant effect on the cutting energy consumption. The optimal combination of cutting parameters was an average cutting speed of 0.5 m/s, cutting clearance of 1.4 mm, wedge angle of 25°, and tool cutting edge inclination angle of 20°. With this combination of parameters, the corresponding peak cutting force was 644.38 N, and the cutting energy consumption was 5.90 J, which was less than 5% relative error between each performance index and the theoretical optimized value.

  • Researchpp 6341-6357Feng, C., Zhou, J., Xu, X., Jiang, Y., Shi, H., and Zhao, G. (2022). "Three-dimensional bioprinting and electrospinning of cellulose nanocrystal/polycaprolactone for tracheal scaffolds," BioResources 17(4), 6341-6357.AbstractArticlePDF

    Three-dimensional printing (3DP) has high flexibility and controllability, and has attracted extensive attention in the biomedical field. However, the scaffolds prepared only by 3D bioprinting have poor mechanical properties, and they cannot effectively carry the required drugs. At the same time, compared with the size of cells, the pore size of 3D printed scaffolds is relatively large, and the efficiency of cell inoculation and tissue formation are still limited by the pore resolution of scaffolds. Therefore, a new method of forming 3D printing trachea composites is proposed. When combined, 3D bioprinting and electrospinning (ESP) can overcome the issues associated with scaffolds prepared by 3D bioprinting alone. Nanofibers create a suitable environment for cell growth. In terms of material use, Polycaprolactone (PCL) is commonly used as an ideal material source for 3D printing, but its biomechanical properties are insufficient. Cellulose nanocrystals (CNC) can effectively improve the properties of polymers such as PCL. Therefore, the inner layer of the scaffold used in tracheal surgery is created from PCL/CNC composite by 3D bioprinting, and the outer nano-cellulose film is deposited on the inner surface by electrospinning. Mechanical properties and cell adhesion/growth of scaffolds prepared by 3D bioprinting combined with electrospinning were found to be superior to those of scaffolds prepared by 3D bioprinting.

  • Researchpp 6358-6376Aytin, A., and Çakıcıer, N. (2022). "Weathering’s effect on color and roughness in some heat-treated wood species with modified water-based varnish," BioResources 17(4), 6358-6376.AbstractArticlePDF

    Heat treatment in wood materials and the use of water-based varnishes (WBV) in furniture made from heat-treated wood materials come to the fore in terms of supporting environmentally friendly production in the wood sector. In this study, the total color changes (ΔΕ*) and surface roughness (SR) were investigated after heat-treated tree species were exposed to natural and accelerated weathering with and without varnish. In this context, test samples were first divided into two groups. Surface treatment was applied to the samples in the first group by applying modified WBV (A1) and normal WBV (A2), and the second group was left unvarnished. Then, one group of the varnished samples was subjected to natural weathering (NAT) for 90 days and the other group was subjected to accelerated weathering (QUV) for 720 h with VAS samples, and then the ΔΕ* and SR values of the samples were calculated. The results revealed that ΔΕ* was the lowest in the QUV WBV group, and NAT was more effective than QUV in ΔΕ*. The highest SR values among all groups were measured in the VAS group, and among the varnished samples, there was no statistical difference between A1 and A2 in SR values, except for Rq.

  • Researchpp 6377-6396Yi, W., Feng, F., Yuan, X., Hao, J., Guo, Y., and Lu, B. (2022). "Transcriptome analysis reveals the molecular patterns regulating prickle reduction in grafted Zanthoxylum armatum," BioResources 17(4), 6377-6396.AbstractArticlePDF

    Grafting has been found to effectively reduce the prickly nature of Zanthoxylum armatum seedlings, but the molecular mechanisms are unclear. A comparative transcriptome analysis was performed on stems (JJ) and leaves (JY) of grafted stems (SJ) and leaves (SY) of non-grafted Zanthoxylum armatum seedlings. The authors obtained 3097, 2124, 5995, and 5043 differentially expressed genes from JJ vs. SJ, JY vs. SY, JY vs. JJ, and SY vs. SJ with 17 co-expressed genes. The RNA-seq results were confirmed by qRT-PCR analysis. Function annotations showed that many DEGs enriched plant hormone signal transduction, phenylpropanoid biosynthesis, and plant-pathogen interaction. Secondary metabolites associated with stress-related hormones and defense were noticeably up-regulated in grafted plants. However, key enzymes regulating lignin synthesis were slightly down-regulated in grafted plants. Additionally, grafted plants had several noticeable up-regulated stress-response TFs (transcription factors), including NAC (NAM, ATAF1/2, CUC1/2), ERF (ethylene response factor), MYB (v-myb avian myeloblastosis viral oncogene homolog), bHLH (basic helix-loop-helix), and WRKY. This study generated abundant sequences for elucidating the genetic differences between grafted and non-grafted Z. armatum.

  • Researchpp 6397-6410Shi, D., Hu, X., Zhang, J., and Du, H. (2022). "Shear stiffness of notched connectors in glue laminated timber-concrete composite beams under fire conditions," BioResources 17(4), 6397-6410.AbstractArticlePDF

    Shear connectors ensure effective interaction between wood beams and concrete slabs of composite beams, and their properties noticeably affect the fire resistance of timber-concrete composite beams. To investigate the shear stiffness of notched connectors in glued laminated timber (GLT)-concrete composite beams under fire conditions, 16 shear tests were conducted. The effects of fire duration and notch length on shear properties of the connectors for a given spacing were studied. The fire tests indicated that the reduction of the notch length from 200 mm to 150 mm remarkably affected the failure mode of the shear specimens, changing from compression failure of notched wood to shear failure of notched concrete. The increase in fire duration reduced effective width of the notched wood, negatively affected the shear stiffness and shear capacity of the connectors, and the shear stiffness decreased more rapidly. The notch length did not have a substantial effect on the shear stiffness of connectors. Based on the experimental results, an analytical model to estimate the shear stiffness of notched connectors in GLT-concrete beam under fire conditions was established.

  • Researchpp 6411-6444Yue, X., Li, Z., Lam, S., Peng, W., and He, Y. (2022). "Reuse of Cornus officinalis nutlet for bioenergy," BioResources 17(4), 6411-6444.AbstractArticlePDF

    As a traditional nourishing Chinese herbal medicine, Cornus officinalis Sieb. et Zucc. has a long history of application. At present, only the flesh of the fruit of Cornus officinalis is used as a medicine, which wastes a large quantity of ingredients in the nutlet. To improve the comprehensive utilization efficiency of the fruit’s nutlet, which could be used when there is a shortage of the plant’s fruit in the market, this study used Fourier transform-infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS), thermogravimetric (TG) analysis, pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS), and nuclear magnetic resonance (NMR) techniques to analyze the Cornus officinalis nutlet. The results showed that the active ingredients of Cornus officinalis nutlet have great medicinal value and could become a substitute for the fruit. After extracting the active ingredients, the residue can be used as a good biomass liquid fuel, providing reference for the future to replace fossil fuels. This study provides the scientific basis for the comprehensive utilization of high-quality resources for Cornus officinalis.