Yongning Yuan¹, Dong Zhang², Usama Sayed³, Hao Zhu¹, Jun Wang⁴, Xiaojun Yang², Zheng Wang^2,*

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.028764

Abstract In order to optimize the wood internal quality detection and evaluation system and improve the comprehensive utilization rate of wood, this paper invented a set of log internal defect detection and visualization system by using the ultrasonic dry coupling agent method. The detection and visualization analysis of internal log defects were realized through log specimen test. The main conclusions show that the accuracy, reliability and practicability of the system for detecting the internal defects of log specimens have been effectively verified. The system can make the edge of the detected image smooth by interpolation algorithm, and the edge detection algorithm… More >

Qifeng Shan^1,2, Ming Mao², Yushun Li^3,*

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.029445

Abstract A theoretical analysis of upward deflection and midspan deflection of prestressed bamboo-steel composite beams is presented in this study. The deflection analysis considers the influences of interface slippage and shear deformation. Furthermore, the calculation model for flexural capacity is proposed considering the two stages of loading. The theoretical results are verified with 8 specimens considering different prestressed load levels, load schemes, and prestress schemes. The results indicate that the proposed theoretical analysis provides a feasible prediction of the deflection and bearing capacity of bamboo-steel composite beams. For deflection analysis, the method considering the slippage and shear deformation provides better accuracy.… More >

John Freddy Gelves Díaz^1,*, Ludovic Dorkis², Richard Monroy-Sepúlveda¹, Sandra Rozo-Rincón¹, Gabriel de Jesús Camargo Vargas³

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.029267

Abstract The material associated with tree pruning in a city in the Colombian neotropics was characterized in order to determine its energy potential. The species studied for their relevance in the territory were Prosopis juliflora, Licania tomentosa, Terminalia catappa, Azadirachta indica, Pithecellobium dulce, Ficus benjamina and Leucaena leucocephala. Moisture content, bulk density, hygroscopic response, elemental chemical analysis, proximal analysis, calorific value, ease of ignition and combustion, thermogravimetric and heat flow analysis, steam generation capacity, and qualitative analysis of gases (mass spectrometry) were determined. The results that were obtained show high initial moisture contents that vary between 37% and 67% and a… More >

Mingyue Miao^1,#, Fei Wang^1,#, Qing Li¹, Longchen Tao¹, Chenchen Dai¹, Yu Liu¹, Shujuan Han¹, Wenshuai Chen^1,*, Ping Lu^2,*

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.030412

Abstract The rheological properties of nanocellulose aqueous suspensions play a critical role in the development of nanocellulose-based bulk materials. High-crystalline, high-aspect ratio, and slender nanofibrillated cellulose (NFC) were extracted from four biomass resources. The cellulose nanofibrils and nanofibril bundles formed inter-connected networks in the NFC aqueous suspensions. The storage moduli of the suspensions with different concentrations were higher than their corresponding loss moduli. As the concentration increased, the storage and loss modulus of NFC dispersion increased. When the shear rate increased to a certain value, there were differences in the changing trend of the rheological behavior of NFC aqueous suspensions derived… More > Graphic Abstract

Yan Yan, Junpeng Dong, Haibo Hu, Susu Yang, Lin Liu, Lei Qin^*

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.028099

Abstract One strain of Hypoxylon sp. CXM-3 and one strain of Sistotrema brinkmannii CXM-4 were inoculated onto sterilized cherry, poplar, birch, and basswood sheets in a certain shape and incubated at constant temperature and humidity for 4, 8, 12, and 16 weeks, respectively, to analyze whether the grain pattern formed by the zone lines was consistent with the predetermined pattern. The results showed that the zone lines of CXM-3 of Hypoxylon were free, delicate, and soft, with brown lines and black staining, mostly accompanied by black and brown dots, facets, and clusters, while the zone lines of CXM-4 of Sistotrema brinkmannii… More >

Lei Liu^*, Shenao Pang, Zhuhui Luo

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.028192

Abstract The recycling of carbon fibers and protection from unwanted microwave radiation are two important environmental issues that need to be addressed in modern society. Herein, branched carbon nanofibers (CNFs) were grown in-situ on recycled carbon fibers (RCFs) through the chemical vapor deposition method using nickel as catalysts and thiophene as aided-catalysts. The effect of thiophene on the growth morphology of CNFs was investigated. Correspondingly, branched CNFs-RCFs and straight CNFs-RCFs were respectively obtained in the presence and absence of thiophene. The microstructure and electromagnetic behaviour investigations have shown that the branched CNFs possess a typical multi-branched structure, with more defects, pores… More >

Ruyi Luo, Yanyan Hu^*, Tingshu He^*, Xiaodong Ma, Yongdong Xu

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.027592

Abstract The measures of steam curing and early-strengthening agents to promote the precast components to reach the target strength quickly can bring different degrees of damage to the concrete. Based on this, the new nanomaterial CSH-the hydration product of cement effectively solves these measures’ disadvantages, such as excessive energy consumption, thermal stress damage, and the introduction of external ions. In this paper, the effect of CSH on the early strength of precast fly ash concrete components was investigated in terms of setting time, workability, and mechanical properties and analyzed at the microscopic level using hydration temperature, XRD, and SEM. The results… More >

Liang Wen^1,2,*, Changhong Yan³, Yehui Shi⁴, Zhenxiang Wang⁴, Gang Liu⁴, Wei Shi⁴

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.027671

Abstract The treatment of wheat straw is very difficult, and its utilization rate is very low; accumulation causes air pollution and even fire. To make full use of wheat straw resources, we examined how using different physical and chemical methods to treat the wheat straw which can improve its strength abilities, or enhance the activity of wheat straw ash. In terms of concrete additives, it can reduce the amount of cement used. In this paper, we found that alkali treatment can significantly improve the tensile strength of wheat straw fiber, but polyvinyl alcohol treatment has no obvious effect on the strength… More >

Xiaoyu Gu¹, Linbi Chen², Seithati Mapesela³, Zheng Wang^1,*, Aijin Zhou⁴

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.028768

Abstract The bamboo scrimber is an anisotropic material. The elastic constant values of the bamboo scrimber specimens measured by the dynamic and static methods are consistent, and the dynamic test method has the advantages of rapidity, simplicity, good repeatability, and high precision. Bamboo scrimber has strong potential as a building material, and its elastic constant is an important index to measure its mechanical properties. To quickly, simply, non-destructively, and accurately detect the elastic constant of the bamboo scrimber, they were dynamically tested by the free plate transient excitation method and cantilever plate torsional vibration method. The static four-point bending method was… More >

Bengang Zhang^1,*, Antonio Pizzi^2,*, Mathieu Petrissans¹, Anelie Petrissans¹, Colin Baptiste¹

Journal of Renewable Materials, Vol., , DOI:10.32604/jrm.2023.029761

Abstract Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many, if not all of the tannin hydroxyl groups with –NH₂ groups. A tannin-aminated tannin (ATT) particleboard coating was then prepared by reacting raw tannin extract with aminated tannin extract and thus cross-liking the two by substituting tannin’s hydroxyl groups with the –NH₂ groups on the aminated tannin to form –NH-bridges between the two. The resulting particleboard coating gave encouraging results when pressed at 180°C for 3 min. Conversely, the system in which tannin was reacted/cross-liked with urea (ATU) by a similar amination reaction… More >