Qiong Liu, Jianzhuang Xiao^*, Amardeep Singh

Journal of Renewable Materials, Vol.9, No.7, pp. 1309-1327, 2021, DOI:10.32604/jrm.2021.015326 - 18 March 2021

Abstract The failure characteristics of recycled concrete containing brick aggregates are still indistinct, especially how the angular aggregates effect the crack propagation. Based on the concept of modeled concrete, the development of cracks in concrete containing the natural aggregate and brick aggregate under a compression loading was studied. The strain distribution was analyzed with the Digital Image Correlation (DIC). The modeled aggregates include circular and squared ones, and the squared modeled aggregates were placed in different orientations, including 0°, 22.5° and 45°. The results show that when the aggregate is placed at 45°, the upper and… More >

Ruyuan Yang¹, Haitao Li^2,*, Assima Dauletbek^1,2, Mahmud Ashraf^2,4, Rodolfo Lorenzo³, Youfu Sun¹, Yuehong Wu¹

Journal of Renewable Materials, Vol.9, No.7, pp. 1293-1307, 2021, DOI:10.32604/jrm.2021.015296 - 18 March 2021

Abstract This paper presents an experimental investigation to identify suitable indices to assess durability of glulam when subjected to freeze-thaw cycles in an exposed enviroenment. In this study, two types of glulam specimens were tested for their performance when subjected to different levels of aging due to freezing and thawing. Effect of aging treatment on various parameters including thickness swelling rate, static bending strength, elastic modulus, shear strength, and peeling rate of adhesive layer were studied. Obtained results showed that freeze-thaw aging treatment did not affect the water-resistance of the specimens as measured by thickness swelling… More >

P. Pesante¹, K. Saavedra^2,*, G. Pincheira²

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 4061-4079, 2021, DOI:10.32604/cmc.2021.015268 - 01 March 2021

Abstract This work proposes to study the effective elastic properties (EEP) of a wood-plastic composite (WPC) made from polyethylene terephthalate (PET) and Chilean Radiate pine’s wood flour, using finite element simulations of a representative volume element (RVE) with periodic boundary conditions. Simulations are validated through a static 3-point bending test, with specimens obtained by extruding and injection. The effect of different weight fractions, space orientations and sizes of particles are here examined. Numerical predictions are empirically confirmed in the sense that composites with more wood flour content and bigger size, have higher elastic modulus. However, these More >

Mateusz Barczewski^1,*, Jacek Andrzejewski^1,*, Radomir Majchrowski², Kamil Dobrzycki¹, Krzysztof Formela³

Journal of Renewable Materials, Vol.9, No.5, pp. 841-853, 2021, DOI:10.32604/jrm.2021.014490 - 20 February 2021

Abstract Agricultural waste is a still untapped source of materials that can, in case of proper utilization, significantly improve the sustainability of polymers and their composites. In this work, polymer composites based on isotactic polypropylene were produced incorporating ground sunflower husk in the amount of 10 wt% and 20 wt%. The work’s main objective is to evaluate how preliminary fractioning of this agricultural waste filler affects the thermomechanical properties, microstructure and surface topology of polypropylene-based injection molded composites. The composites were analyzed for mechanical properties (tensile, impact strength and hardness), thermomechanical properties (Vicat softening point VST,… More >

Hui Zhan^1,2, Zhaohui Niu¹, Lixia Yu¹, Maobiao Li¹, Changming Wang¹, Shuguang Wang^1,*

Journal of Renewable Materials, Vol.9, No.5, pp. 1031-1043, 2021, DOI:10.32604/jrm.2021.014109 - 20 February 2021

Abstract The durability of bamboo based on its chemical and mechanical properties is a crucial consideration for the wood-based industry due to its vulnerability to insects and microorganisms. We investigated the dynamic changes of chemical and mechanical properties of Phyllostachys edulis under air-dry and water storage conditions for 3, 6 and 12 months respectively. The chemical properties of P. edulis bamboo culms varied with culm age but insignificantly with culm height. The mechanical properties of P. edulis culms showed an increasing trend with culm age. Water storage condition decreased the ash, SiO₂ and lignin content, but increased the ethanol-benzene extracts. More >

Zhichao Lou^1,2, Tiancheng Yuan¹, Qiuyi Wang¹, Xinwu Wu¹, Shouheng Hu¹, Xiaomeng Hao¹, Xianmiao Liu^3,*, Yanjun Li^1,*

Journal of Renewable Materials, Vol.9, No.5, pp. 959-977, 2021, DOI:10.32604/jrm.2021.014285 - 20 February 2021

Abstract This work aimed to help the bamboo industry develop methodology for producing imperfection-free bamboo boards that can serve either decorative or structural benefit to consumers seeking to engage with the bioeconomy. Specifi- cally, softened and slotted bamboo tubes were handled by a roller device with nails to render crack-free flattened bamboo board. Softening temperature and time were optimized herein according to findings regarding chemical composition and board mechanical properties. The optimal softening parameters for saturated steam heat treatment is proved to be 160°C for 8 minutes. The flattened bamboo board possesses an increased bending strength… More >

Mengyuan Cao, Yi Xu^*, Yilin Dong

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 123-139, 2021, DOI:10.32604/fdmp.2021.011443 - 09 February 2021

Abstract The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes. Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating. The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries (UAs) through experiments and simulation. The results of experiments show that, for the case of magnetic warming comparing with the conventional water bath, magnetic warming presents better preservation of extracellular matrix (ECM), collagen fibers, elastic fibers, and… More >

Yiran Tian^*

Molecular & Cellular Biomechanics, Vol.18, No.1, pp. 41-49, 2021, DOI:10.32604/mcb.2021.014394 - 26 January 2021

Abstract Rope skipping is popular as it is easy to learn; thus, it has developed into a competitive sport. The research on the biomechanical properties of rope skipping can effectively improve training efficiency and reduce injury probability. This paper briefly introduced the characteristics of single-swing and multi-swing techniques in competitive rope skipping, selected ten second-grade athletes as the subjects to test the single-swing and triple-swing rope skipping, and tested the biomechanical properties in the process of rope skipping. The results showed that the variation range of the lower limb joint angle in the triple-swing rope skipping… More >

Jin Wang¹, Weigang Zhang^2,*, Xiaowei Zhuang^1,*

Journal of Renewable Materials, Vol.9, No.3, pp. 557-568, 2021, DOI:10.32604/jrm.2021.013269 - 14 January 2021

Abstract Using 1–8 years bamboo as materials, the content of different chemical constituent was tested, and the reactive oxygen species (ROS) free radicals produced from laccase treated bamboo were detected by electron spin-resonance (ESR) spectroscope. The wet-process particleboard was made from laccase-treated bamboo by hot pressing and board mechanical properties including internal bond strength (IB), modulus of rupture (MOR) and thickness swelling (TS) after 2-hours water absorption were tested under different conditions. Results showed that laccase mainly catalyze the bamboo components and improved the bonding strength of laccase-treated boards. By ESR measurement on each single component More >

Lu Hong¹, Biqing Shu^1,2, Qian He¹, Zehui Ju¹, Haiyang Zhang¹, Xiaoning Lu^1,*

Journal of Renewable Materials, Vol.9, No.1, pp. 49-59, 2021, DOI:10.32604/jrm.2021.013833 - 30 November 2020

Abstract Chinese fir was compressed by vacuum hot pressing and conventional hot pressing at different temperatures (180°C, 200°C and 220°C), respectively. The color parameters of the heat-compressed sample were measured, the relative mechanical properties of the material were tested and changes in the chemistry of fir were investigated using Fourier transform infrared spectroscopy (FTIR) and Xray photoelectron spectroscopy (XPS). The results indicated that the color difference between compressed and untreated wood increased gradually with the increase of temperature. Compared with the conventional hot pressing treatment, the color difference (ΔE*) of the Chinese fir treated by vacuum More >