Research Articles

This study was conducted to propose an accurate measurement method of charred thickness in structural glued laminated timber (glulam) exposed to standardized fire temperature conditions for evaluation of the fire resistance of Japanese larch (Larix kaempferi) structural glulam. The compressive strength of the test piece collected from the structural glulam exposed to the standardized fire temperature for two hours was analyzed. The results showed that there was residual strength of 14% in the boundary area between sound and charred part. Therefore, the thickness of charred part should be calculated as approximately 4.5 mm less than what is measured visually. The cell wall thickness between sound-, boundary-, and charred-part exposed to high temperature was observed under a microscope. Higher temperature resulted in a thinner tracheid cell wall, and the radial tissue was broken down. The transformation of the boundary part of these microstructures progressed gradually until full carbonization of wood occurred. Based on compressive strength tests and microscopic observation in the boundary part of specimens exposed to high temperature, the current visual assessment of charred thickness measurement is safe in terms of structural aspect but not efficient in terms of wood utilization point of view due to exception of load carrying area of the member.

Hardness, surface roughness, and adhesion strength were determined for water-based opaque paints applied to heat-treated wood material surfaces. For this purpose, Scotch pine (Pinus sylvestris L.) and beech (Fagus orientalis Lipsky) woods were used as experimental material. Specimens were subjected to heat treatment at 3 different temperatures (150, 180, and 210 °C) and 2 different periods (2 and 4 h) under laboratory conditions. Two-component water-based paints with commercial codes D17 and D45 were applied to the surfaces. The hardness, surface roughness, and adhesion strength values of painted samples were determined according to the applicable standards. The results showed that there were higher values of hardness and surface roughness of water-based paints in short-term heat treatment compared with long-term heat treatment. A general decrease in pine with D17 and D45 paints applied to the surfaces and in beech with D45 in adhesion strength was detected depending on the increasing heat treatment temperature and duration. An increase was observed in beech samples with D17 paint applied.

Environmental and economic concerns are driving tissue paper manufacturers to improve understanding of the relationships between fibres, the networks they form, the forming process, and the final tissue paper properties. This work investigated how pulp fractionation, refining, or addition of microfibrillated cellulose (MFC) affect the compromise between absorbency and strength of 33 ± 2 g/m² model papers made of bleached eucalyptus kraft pulp. The results showed that the compromise of properties was better when fibres were refined than when MFC was added. The absorbency capacity of 2%wt MFC-paper was almost 20% lower than the capacity of the refined paper at the same dry strength. The calculated additional storage capacity due to water-induced deformations of the fibre network was 40% lower in the same range of bulk. By forming a high viscosity gel at inter-fibre contacts, MFC could limit the occurrence of major fibre and network deformation mechanisms when water was imbibing the paper.

Carbon fiber (CF)-filled fiberboard specimens for electromagnetic (EM) shielding applications were produced in this study by mixing CF with wood fiber (WF). The aim of this work was to study the panel properties with different loadings (1%, 2%, 3%, 5%, and 10%) of CF. The mechanical, physical, and electromagnetic interference (EMI) shielding properties of the produced medium density fiberboard (MDF) were analyzed. The shielding effectiveness (SE) of the CF1 sample was 23.5 dB to 35.0 dB in the frequency range of 8.2 GHz to 12.4 GHz. The maximum SE of 64 GHz to 76 dB was obtained for the CF10 sample. The investigation of the mechanical properties of MDF panel indicated that the modulus of rupture (MOR), modulus of elasticity (MOE), and internal bonding (IB) of the composite panels were less than those of the control panel. The MOR, MOE, IB, thickness swelling (TS), and water absorption (WA) of the panel with 1% CF (CF1) were 24.7 MPa, 2,510 MPa, 0.69 MPa, 14.5%, and 52.3% respectively. Generally, the MDF panels with 1% CF exhibited a greater ability for EM shielding applications because of their acceptable properties according to the EN 622-5 (2019) standard and appropriate EM shielding of at least 20 dB.

Laccase has huge potential application in all aspects of biotechnology due to the ability of laccase to oxidize a wide range of phenolic and non-phenolic compounds. The future success of such applications requires large amounts of laccase with low costs. White-rot fungi are important groups of laccase production. In this study, three white-rot fungi, Phlebia acerina Han 618, Trametes hirsuta Han 726, and Coriolopsis trogii Han 751, isolated from a native North China habitat, were identified by the method of molecular biology and preliminary screening of the ability of laccase-production by guaiacol selection medium. Then they were fermented on different lignocellulosic biomass. Three species showed consistency in preference of lignocellulosic biomass, and the presence of stalk of Sorghum bicolor was more suitable for secreting laccase. The capacity of laccase secretion from different species was significantly different. The capacity of secreting laccase of C. trogii Han 751 was superior to that of P. acerina Han 618 and T. hirsuta Han 726. The discovery of a new strain with superior capacity of secreting laccase and suitable lignocellulosic biomass were helpful for laying a foundation for the optimization of the fermentation conditions for the highest laccase production, the isolation and purification of laccase, and the industrial application of laccase.

Consumer preferences were examined with respect to the decision-making process to purchase home and office furniture in Iran. A conceptual model was proposed based on the theoretical framework from literature. The data was obtained from interviews with customers who were buying wooden furniture. The main data collection tool in this study was a questionnaire. The results were processed using structural equation modelling (SEM) in SmartPLS software. SEM is a multivariate method that combines multiple regression and factor analysis aspects. PLS-SEM has been increasingly developed in various fields in recent years, due to its usability in nonnormal data, small sample sizes, and the use of formative indicators. The findings revealed a significant relationship between all research factors and consumer preferences of home and office furniture, although the model quality assessment showed that safety and environment (0.576=strong effect), salesperson’s characteristics (0.197=medium effect), corporate responsibility factors (0.058=weak effect), internal factors (0.029=weak effect), and product characteristic (0.023=weak effect) had the highest impact. These independent variables accounted for 93.8% of the changes of the dependent variable of consumer preferences.

A high yield cellulase production strain was screened from the surface of cigar wrapper leaves and added to cigar wrapper leaves for fermentation in the present study. The enzyme-producing strain was identified as Bacillus velezensis, and its maximum carboxymethyl cellulase activity could reach 44.3 U/mL. Making the cellulose degradation rate of cigar wrapper leaves as the index, the fermentation temperature, inoculum concentration, and carbon and nitrogen source addition concentration were optimized by response surface methodology. The results showed that under the conditions of inoculation concentration of 20%, fermentation temperature of 37 °C, addition of 4.5 ‰ glucose and 2.25 ‰ glutamate, the highest degradation rate of tobacco cellulose was 31.7%. Significance analysis results showed that the order of factors affecting the degradation rate of cigar wrapper cellulose was: inoculation concentration > carbon and nitrogen source addition concentration > temperature. The analysis of aroma substances under the optimal conditions found that the total amount of aroma substances of cigar wrapper increased by 26.1% compared with that before fermentation, in which β-damascenone, megastigmatrienone, farnesyl acetone, and solanone were significantly improved. The results were conducive to improving the aroma quality and concentration of cigar wrapper leaves.

The pH is one of the key factors affecting microbial activity in anaerobic systems. In this paper, the pH impact tolerance of Fe0/GO (zero-valent iron/graphene oxide) mediated anaerobic treatment system for high concentration organic wastewater was studied. The effects of a Fe0/GO mediated anaerobic system on wastewater treatment, degradation kinetics, and the physicochemical properties of sludge were studied at pHs of 5.5 and 8.5; the separate addition of Fe0 and GO and a blank system were used as the blank control. The results showed that the pH had adverse effects on the treatment of each system and the physicochemical characteristics of sludge. However, the Fe0/GO system under pH shock maintained a relatively high CODCr removal rate and gas production; the effluent volatile fatty acid content was the lowest, the effluent pH value deviation from the normal range was small, the degradation rate constant, and sludge concentration and flocculation performance of the mixed liquid were better than those of other systems. The recovery phase of Fe0/GO returned to normal in a relatively short time. These results showed that adding Fe0/GO to the anaerobic treatment of high concentration organic wastewater system can drastically improve the pH shock resistance of the system.

A densification method is proposed and developed to improve the mechanical properties of Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) woods. The method, called Thermo-Vibro-Mechanic® densification, is derived from the hypothesis that the vibration added to the traditional thermo-mechanical densification process can cause the wood cell walls to interlock with each other at the micro-level via the friction effect. In addition, it aims to remove the cell cavities under lower pressure compared to other densification methods via the shaking effect. To test this hypothesis, the samples, obtained in both the radial and tangential directions, were pre-treated with wood stain and preservative before undergoing the densification process. Thermo-Vibro-Mechanic® densification was performed at varying temperatures (100, 120, and 140 °C), pressures (0.60, 1.00, and 1.40 MPa), and durations (20, 60, and 100 s). The changes in the values of the bending strength, modulus of elasticity, and compression strength parallel to the grain in the radial and tangential directions were determined accordingly. The results showed that the Thermo-Vibro-Mechanic® densification process increased the bending strength and modulus of elasticity values up to 50%, while the compression strength reached 67% higher than the untreated wood.

In recent years, people’s acceptance of online shopping has increased markedly with the gradual maturing of e-commerce. The furniture industry in China, along with many other countries, is paying increased attention to the online retail business. The furniture online consumption experience has attracted attention both in academic and industrial fields. The purpose of this paper is to provide a literature review of the furniture online consumption with an aim to extend the concept of consumer experience to the context of online furniture consumption. The paper offers three important contributions for both academics and practitioners. First, it analyzes the main influencing factors of the consumer experience concerning wood furniture online consumption in China. And secondly, it proposes a conceptual framework of furniture online consumer experience (FOCE), which divides online consumption experience into three dimensions: perceived risk experience, emotional experience, and new technology interactive experience. Finally, from a managerial perspective, the authors put forward constructive strategies in terms of furniture online sales. The findings of this study afford practical implications for the improvement of the online shopping experience of consumers for furniture companies.