NC State
  • Editorialpp 1-3Yao, Y. (2017). "Models for sustainability" BioRes. 12(1), 1-3.  AbstractArticlePDF
    As one of the major methodologies used in the modeling of sustainability, Life Cycle Assessment (LCA) is widely used to evaluate the environmental impacts of emerging technologies and to enhance decision making towards sustainable development. However, most of the current LCA models are static and deterministic. More insights could be generated when LCA models are coupled with higher-resolution techniques in a prospective fashion. Instead of trying to accurately predict the future, the purpose and value of integrated prospective models are to explore the boundaries of possibility and to shed light on directions that can lead to sustainable pathways. The biggest challenge is to determine the appropriate model resolution so that both big-picture insights and critical details are included. This challenge is hard to address, especially for interdisciplinary models that try to incorporate more than one dimension related to sustainability. However, improvements can be made continually through efforts from a growing population of interdisciplinary researchers.
  • Editorialpp 4-7Derikvand, M., Nolan, G., Jiao, H., and Kotlarewski, N. (2017). "What to do with structurally low-grade wood from Australia's plantation eucalyptus; Building application?," BioRes. 12(1), 4-7.AbstractArticlePDF

    About one million hectares of plantation hardwoods, mostly eucalyptus trees of different sub-species (E. nitens and E. globulus), are annually being managed in Australia, which provides a promising resource of raw materials for fibre industries. However, the timber boards required by the Australian hardwood sector are still being either imported from other countries or harvested from the native forests. There is a need to find a practical way to use the plantation eucalyptus in the Australian timber industry. However, the fibre-managed plantation eucalyptus produces structurally low-grade timber which could not be used as individual boards for structural applications—such as building construction. Unsuitable for appearance applications, the structurally low-grade boards may be suitable for producing innovative high-mass engineered timber products. This editorial will briefly discuss drivers, opportunities, and challenges associated with conducting such a research project.

  • Researchpp 8-18Chen, T., Wu, Z., Wei, W., Xie, Y., Wei, Q., Wang, X., Hagman, O., and Karlsson, O. (2017). "Optimizing refining conditions of Pinus massoniana cellulose fibers for improving the mechanical properties of ultra-low density plant fiber composite (ULD_PFC)," BioRes. 12(1), 8-18.AbstractArticlePDF
    Response surface methodology was used to optimize the refining conditions of Pinus massoniana cellulose fiber and to improve the mechanical properties of ultra-low density plant fiber composite (ULD_PFC). The effects and interactions of the pulp consistency (X1), the number of passes (X2), and the beating gap (X3) on the internal bond strength of ULD_PFC were investigated. The results showed that the optimum internal bond strength (91.72 ± 2.28 kPa) was obtained under the conditions of 8.0% pulp consistency, two passes through the refiner, and a 30.0 μm beating gap. Analysis of the physical properties of the fibers and handsheets showed that the fibrillation of fibers with optimum refining conditions was improved. Also, the tear index of the optimal specimen was 13.9% and 24.5% higher than specimen-1 with a lowest beating degree of 24 oSR and specimen-6 with a highest beating degree of 73 oSR, respectively. Consequently, the optimal refining conditions of the fibers are valid for preparing ULD_PFCs.
  • Researchpp 19-28Cao, J., Liang, H., Lin, X., Tu, W., and Zhang, Y. (2017). "Potential of near-infrared spectroscopy to detect defects on the surface of solid wood boards," BioRes. 12(1), 19-28.AbstractArticlePDF

    Defects on the surface of solid wood boards directly affect their mechanical properties and product grades. This study investigated the use of near-infrared spectroscopy (NIRS) to detect and classify defects on the surface of solid wood boards. Pinus koraiensis was selected as the raw material. The experiments focused on the ability to use the model to sort defects on the surface of wood into four types, namely live knots, dead knots, cracks, and defect-free. The test data consisted of 360 NIR absorption spectra of the defect samples using a portable NIR spectrometer, with the wavelength range of 900 to 1900 nm. Three pre-processing methods were used to compare the effects of noise elimination in the original absorption spectra. The NIR discrimination models were developed based on partial least squares and discriminant analysis (PLS-DA), least squares support vector machine (LS-SVM), and back-propagation neural network (BPNN) from 900 to approximately 1900 nm. The results demonstrated that the BPNN model exhibited the highest classification accuracy of 97.92% for the model calibration and 97.50% for the prediction set. These results suggest that there is potential for the NIR method to detect defects and differentiate between types of defects on the surface of solid wood boards.

  • Researchpp 29-42Abdul Khalil, H. P. S., Tye, Y. Y., Chow, S. T., Saurabh, C. K., Paridah, M. T., Dungani, R., and Syakir, M. I. (2017). "Cellulosic pulp fiber as reinforcement materials in seaweed-based film," BioRes. 12(1), 29-42.AbstractArticlePDF
    Composite materials made from renewable resources can minimize the environmental pollution. In this work, biocomposite films were produced using seaweed as matrix and empty fruit bunch (EFB) pulp fibers as reinforcement. Based on the results, the EFB pulp-seaweed composite films exhibited better mechanical properties than the seaweed film. It was also observed that 50% EFB pulp loading gave the highest tensile strength (81.4 MPa) and elongation at break (5.4%). This phenomenon was supported by SEM analysis, in which more fiber breakage than fiber pull-out was observed on the tensile fracture surface of composite film. Additionally, no agglomeration of the pulp fibers was observed. Instead, the pulp fibers were homogenously distributed throughout the film. In contrast, the contact angle of the seaweed-based films started to decrease once the pulp fibers were added. The decrease in the contact angle was attributed to the hydrophilic nature of the pulp fibers. Nevertheless, the contact angle values of all composite films were still comparatively high and thus, this would not affect their application as a packaging film.
  • Researchpp 43-55Guo, X., Lin, Y., Na, B., Liang, X., Ekevad, M., Ji, F., and Huang, L. (2017). "Evaluation of physical and mechanical properties of fiber-reinforced poplar scrimber," BioRes. 12(1), 43-55.AbstractArticlePDF

    The mechanical properties of poplar scrimber reinforced with glass fiber mesh were investigated. The influence of the different structures and densities were studied with respect to the modulus of rupture (MOR), modulus of elasticity (MOE), and impact toughness (IT). The glass fiber improved the mechanical properties of poplar scrimber. The MOR, MOE, and IT of the scrimber had an obvious dependence on the number of glass fiber layers. When the layers of glass fiber meshes were increased, the MOR, MOE, and IT were increased compared to the control group (scrimber without glass fiber reinforcement). The MOR, MOE, and IT of single-layer glass fiber reinforced scrimber increased a lot compared to the control group. The MOR, MOE, and IT of double-layer glass fiber reinforced scrimber (DGRS) were increased, but the amplitude of the increase was smaller than that of SGRS. Compared to the MOR, MOE, and IT of DGRS, the MOR, MOE, and IT of triple-layer glass fiber reinforced scrimber (TGRS) decreased slightly. When the density was increased, the increasing rate of the MOR, MOE, and IT of the glass fiber reinforced scrimber showed a downward trend, and the glass fiber had better strengthen effects on the scrimber at low density (0.6 g/cm3 and 0.7 g/cm3).

  • Researchpp 56-67Zhang, S. Y., Li, Y. Y., Wang, C. G., and Wang, X. (2017). "Thermal insulation boards from bamboo paper sludge," BioRes. 12(1), 56-67.AbstractArticlePDF
    This study was conducted to evaluate the properties of insulation boards made from bamboo paper sludge and fly ash floating beads. An orthogonal test design was applied to study the effects of certain factors on the properties of the insulation boards. The results indicated that the sequence of significant effect of factors on the properties of the composite boards was particle size of bamboo paper sludge, thickness of boards, and weight ratio of sludge to fly ash floating beads. The verified optimal conditions were confirmed to be 20 to 40 mesh, 80:20, and 14 mm, representing the particle size of bamboo paper sludge, weight ratio of sludge:fly ash floating beads, and thickness of boards, respectively. The thermal conductivity of the bamboo paper sludge and fly ash floating beads insulation boards was measured and suggested that both insulation boards had thermal conductivity values ranging from 0.12 to 0.165 W/mK, which is close to the conventional insulation material lightweight concrete.
  • Researchpp 68-81Ahamad Nordin, N. I. A., Ariffin, H., Hassan, M. A., Shirai, Y., Ando, Y., Ibrahim, N. A., and Wan Yunus, W. M. Z. (2017). "Superheated steam treatment of oil palm mesocarp fiber improved the properties of fiber-polypropylene biocomposite," BioRes. 12(1), 68-81.AbstractArticlePDF

    The effect of fiber surface modification by superheated steam (SHS) treatment and fiber content (30 to 50 wt.%) was evaluated relative to the mechanical, morphology, thermal, and water absorption properties of oil palm mesocarp fiber (OPMF)/polypropylene (PP) biocomposites. SHS treatment of OPMF was conducted between 190 and 230 C for 1 h, then the SHS-treated fiber was subjected to melt-blending with PP for biocomposite production. The biocomposite prepared from SHS-OPMF treated at 210 C with 30 wt.% fiber loading resulted in SHS-OPMF/PP biocomposites with a tensile strength of 20.5 MPa, 25% higher than untreated-OPMF/PP biocomposites. A significant reduction of water absorption by 31% and an improved thermal stability by 8% at T5%degradation were also recorded. Scanning electron microscopy images of fractured SHS-OPMF/PP biocomposites exhibited less fiber pull-out, indicating that SHS treatment improved interfacial adhesion between fiber and PP. The results demonstrated SHS treatment is an effective surface modification method for biocomposite production.

  • Researchpp 82-94Gáborík, J., Gaff, M., Ruman, D., Gašparík, M., Svoboda, T., Vokaty, V., and Síkora, A. (2017). "Quality of the surface of aspen wood after pressing," BioRes. 12(1), 82-94.AbstractArticlePDF

    This paper explores changes in the quality of the surface of aspen wood after pressing. Pressing, a type of processing, facilitates changes in surface quality and smoothness, thereby producing wood suitable for the furniture industry. The results obtained for the pressed wood surface were compared with those obtained for wood surfaces that were not subjected to pressing. Attention was paid to the impact of moisture, the degree of compression, and plasticizing by steam. The change in smoothness/ roughness was monitored in both the longitudinal and transverse directions (relative to the grain). The contact method was used to measure the roughness both before and after pressing. The independent variables of moisture content and degree of compression had the greatest impact on the smoothness/roughness. Plasticizing by steam had no greater impact. Therefore, the non-plasticized aspen wood was determined to be more suitable for the given purpose.

  • Researchpp 95-106Yang, X., Wang, X., Liu, H., Zhao, Y., Jiang, S., and Liu, L. (2017). "Impact of dimethyl sulfoxide treatment on morphology and characteristics of nanofibrillated cellulose isolated from corn husks," BioRes. 12(1), 95-106AbstractArticlePDF

    This work investigated the impact of dimethyl sulfoxide (DMSO) treatment in the isolation of nanofibrillated cellulose (NFC) from corn husk by the 2,2,6,6,-tetramethylpilperidine-1-oxyl (TEMPO) oxidation method. NFC-A and NFC-B were prepared without and with DMSO treatment before TEMPO oxidation. The extracted NFC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), zeta potential analyzer, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the dimension of both NFC-A and NFC-B were in nanoscale. The crystalline type of NFC was cellulose I, and the crystallinity of NFC was obviously increased. The thermal stability of NFC was reduced slightly. Compared with NFC-A, NFC-B had a narrower distribution range, higher crystallinity, and better thermal stability. This result demonstrated that DMSO treatment did not change the chemical structure of NFC, but it affected their dimension and distribution and improved their dispersion stability, crystallinity, and thermal stability.