Volume 20 Issue 1

The aim of the paper was to optimize the settings of the material properties of a computer model describing heat transfer in a wooden beam exposed to thermal loading from a porcelain radiation panel. The methodology was based on performing medium-scale fire tests as a basis for a creation of finite element model with 6 different setups of material characteristics based on the outputs of tests. When adjusting the settings, the T-history method was used to determine a beginning and end of a phase change of the water content in the wood, a thermal conductivity was adjusted based on a density and a moisture content, and enthalpy was used instead of a specific heat. The results of the simulations were compared with the real medium-scale fire tests, which showed the importance of adjusting the input data. Based on the T-history method, the setting with a thermal conductivity value of 0.35 W·m^-1·K^-1 at a temperature of 114.8 °C was shown to be the best, with a coefficient of determination 98.7%.The results of the simulations showed that there could be a correlation between the moisture content of the wood and the maximum value of the thermal conductivity of the wood in the phase change of water.

Fungal endophytes were isolated from the leaves and petioles of Liquidambar orientalis Mill., an endangered species in Türkiye. Plant material was collected from 10 sites in September 2023, yielding 499 fungal isolates, classified into 38 morphological groups. DNA extraction and polymerase chain reaction (PCR) amplification of ITS and Beta-tubulin regions were conducted on representative isolates. All fungi belonged to the Ascomycota phylum, comprising 11 genera and 26 species across 15 families, with one group unidentified. The most prevalent families were Diaporthaceae (34.9%), Pleosporaceae (23.4%), and Botryosphaeriaceae (22.2%), with Diaporthe eres (15.0%) and Phomopsis sp. (12.4%) being dominant species. Fungal diversity was assessed using Shannon, Simpson, and Chao1 indices, revealing tissue type as the strongest factor influencing species diversity, followed by media and spatial factors. The presence of pathogenic families, such as Botryosphaeriaceae, highlights potential threats to the species. This is the first study to report fungal endophytes in L. orientalis, as well as the first records in Türkiye for several species, including Alternaria destruens, Alternaria alstroemeriae, Stemphylium majusculum, Diaporthe cynaroidis, Pseudopithomyces rosae, Nothophoma variabilis, Cladosporium endophyticum, Cladosporium colombiae, Muyocopron sp., Sphaerulina rhododendricola, Constantinomyces macerans, and Aequabiliella effusa.

Waste tires represent an important source of polymer waste. The ground tire rubber derived from waste tires is a recycled product that can be combined with polystyrene (PS) to produce high-performance PS and waste rubber composites. To improve composite material performance, surface grafting modification of waste tire rubber with styrene to enhance properties of PS composites as a novel approach was investigated. The surface morphology and structure of polystyrene grafted waste tire rubber powder via a conventional free radical polymerization were confirmed successfully using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy analyses in addition to the Fourier-transform infrared spectroscopy (FTIR). The comparative mechanical and thermal property analysis of PS sustainable composites with recycling waste tire rubber powder with and without surface grafting modifications indicated an approximate 4-fold increase in the impact strength of polystyrene grafted waste tire rubber reinforced PS sustainable composites in addition to enhanced interfacial miscibility. The development of sustainable composite materials from recycled waste tire provides a novel avenue to achieve close-loop polymer recycling, which is of significance in the development of the circular economy and an environmentally friendly society.

Glycol lignin (GL) produced via acidic solvolysis of cedar wood meal with polyethylene glycol (PEG) is a highly functional material. In this study, the effects of wood meal particle size and amount of PEG added on the properties of PEG400-modified GLs (GL400s) were examined. For this purpose, cedar wood meal with four different particle sizes ranging between 0.18 and 2.00 mm and PEG400 at liquid ratios of 5 and 3 with respect to the wood meal were used. Acidic solvolysis at 140 °C successfully decreased the amount of solid residue with increasing GL400 yield and reaction time at both liquid ratios of 5 and 3. Overall, wood meal size remarkably affected the physical properties of GL400s at low PEG400 content (liquid ratio 3). In addition, the glass transition temperature T_g and thermal flow temperature T_f increased with decreasing wood meal size. Consequently, GL400s with varying thermal properties (T_g = 63 to 97 °C, T_f = 109 to 149 °C) were successfully prepared by adjusting the PEG400 liquid ratios and wood meal size. The data will support the development of a stable manufacturing process for the mass production of GL.

Rice straw lignin (LRS) tends to be dark in color, which makes it less appealing for material applications. Therefore, a bleaching process involving lignin oxidation is of interest. This study aimed to investigate the mechanical and chemical properties of bleached LRS and explore its potential application in PU-based paper coatings. LRS and commercial lignin (LC) were subjected to bleaching using 29% H₂O₂ through oxidation treatment. The bleached lignin was then used to prepare PU-based paper coatings. The effects of bleaching treatment on the functional groups, structural, and thermal properties of lignin, as well as the water resistance of the PU composites were assessed. The oxidation treatment resulted in a reduction in the phenolic hydroxyl content, methoxy content, antioxidant activity, and equivalent weight of lignin. However, LRS exhibited greater thermal resistance than did LC. The bleached LRS was successfully integrated with toluene di-isocyanate (TDI) to produce transparent polyurethane. This polyurethane was then applied as a coating for paper containers, which successfully held cold water for over 4 h without leaking, indicating its outstanding water repellency.

Bamboo is a sustainable material that supports carbon sequestration and helps address the imbalance of timber supply vs. demand. Drying is a crucial step in bamboo processing, in the course of which shrinkage and stress accumulation can lead to defects such as cracking and deformation. Understanding stress and strain development during drying is critical for improving bamboo processing. This review paper explores bamboo’s gradient structure and moisture migration characteristics, focusing on the mechanisms behind shrinkage strain formation and the sources of stress. It reviews literature on bamboo drying and cellular structural changes, evaluating the evolution of stress and strain testing methods, from traditional sectioning techniques to advanced methods such as digital imaging and acoustic emission. The paper also summarizes progress in stress-strain research at both macroscopic and cellular scales. Current challenges include species-specific shrinkage variations, limitations in measurement techniques, and insufficient research on shrinkage above the fiber saturation point. To address these issues, the study recommends developing universal theoretical models, employing advanced detection technologies, comparing shrinkage patterns between bamboo culms and nodes, exploring drying stress composition, and adopting multi-scale research approaches. These strategies aim to enhance the quality of bamboo processing and promote higher-value applications within the industry.

The ‘Malay’ rebab is a vertical, strung chordophone played similarly to a cello. The rebab strings sit on a bridge. The bridge is placed on a buffalo intestine on the front face. The buffalo intestine surface is pressed by the bridge in such a way that the string tension is not in a fully stable position. A ball of beeswax attached near the bridge mutes the sound reverberations. This investigation was undertaken by analyzing the rebab sound utilizing Fast Fourier Transform (FFT) for spectrum analysis via a PicoScope. The highest note is Bb (Bb3 = 0.231 kHz), played on the 1^st string. The intermediate note is F (F3 = 0.172 kHz) played on the 2^nd string. The lowest note is C (C3 = 0.135 kHz), played on the 3^rd string. For string 1, the fundamental pitches (f0) were 0.222 kHz, 0.237 kHz and 0.224 kHz for rebab A, B, and C, respectively. For string 2, the f0 were 0.174 kHz, 0.177 kHz and 0.168 kHz for rebab A, B and C respectively. For string 3, the f0 were 0.125 kHz, 0.149 kHz and 0.126 kHz for rebab A, B and C respectively. All the strings show non-harmonicity.

To address the issue of excessive soil content in straw feed after harvesting by a straw feed harvester, this study designed a dust removal apparatus. Its optimal operating parameters were determined through a combination of numerical simulations and field experiments. Using dust removal efficiency as the evaluation criterion, the Box-Behnken experiment and variance analysis revealed that the factors influencing the dust removal efficiency of the apparatus, in order of significance, were the number of dust removal drums, the aperture of the dust sieve, and the rotational speed of the dust removal drums. The optimal parameter combination consisted of 5 dust removal drums, a dust sieve aperture of 5 mm, and a drum rotational speed of 370 r/min. The dust removal efficiency obtained from numerical simulation using these optimal parameters was 94.1%, while the field verification test yielded an efficiency of 93.5%, with a relative error of 0.64% between the two results, confirming the accuracy of the numerical simulation parameters. The optimized dust removal apparatus significantly improves the quality of straw fodder by reducing dust content, which not only enhances the efficiency of straw recycling but also supports sustainable agricultural practices, promoting both mechanization and green development in the industry.

ZnO nanoparticles were synthesized using the raw juice of Kaffir lime (Citrus hystrix) fruit bya simple and cost-effective green route and its effects on earthworms, Eudrilus eugeniae, were studied. The kaffir-lime powered ZnO nanoparticles (ZnO:KL) were characterized by X-ray diffraction (XRD), UV-Vis-NIR spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The filter paper method was adopted to test the toxicity of ZnO:KL. Earthworms (species Eudrilus eugeniae) were exposed to 100 to 1000 mg/L of ZnO:KL in one-step order. During the study period (up to 48 h), no mortality was found in any treatment group. In histological observation, no damage was found in the epidermal layer of earthworm’s skin treated up to 800 mg/L, whereas slight epidermal damage was observed only in 900 and 1000 mg/L treated earthworms. The GC-MS spectrum of the juice of kaffir lime fruit revealed 22 bioactive compounds. The predominantly identified bioactive compounds vitamin C and citric acid were subjected to molecular docking to reveal their binding affinity with collagen – a structural protein providing strength and flexibility of the earthworm’s body. Vitamin C and citric acid bind to the collagen in a favorable orientation with the binding affinity of -4.44 kcal/mol and -4.97 kcal/mol, respectively. Since vitamin C and citric acid are capable of influencing the biosynthesis of collagen, they could prevent skin damage. In sum, the kaffir lime-powered ZnO nanomaterial is less toxic to the earthworm when compared with bare ZnO.

This study examined the volatile organic compounds (VOCs) in Stropharia rugosoannulata Farlow that were cultivated on four substrates formulated with agricultural and forestry wastes. The VOCs were analyzed by an electronic nose (E-nose), gas chromatography-ion mobility spectroscopy (GC-IMS), principal component analysis (PCA), and an orthogonal partial least squares discriminant analysis (OPLS-DA). A4(40% sawdust, 30% camellia shells, 20% rice husk, 8% bran, and 2% lime) was the most effective overall at determining the quality of flavor. The E-nose showed that there were similar profiles of aromas for A2(100% Eleusine coracana (L.) Gaertn straw) and A3(70% bamboo chips, 20% rice husk, 8% bran, and 2% lime). A total of 91 VOCs, including 82 known compounds, such as formaldehyde, alcohols, esters, and ketones, and 9 unknown compounds, were detected in each sample by GC-IMS. The relative contents of formaldehyde, ketones, alcohols, and esters in the samples was more than 80%. Among the 29 VOCs with variable importance in projection (VIP) values > 1 and P < 0.05, formaldehyde, heptagonal(dimer), 2-methyl-E-2-butenal-M”, 3-methyl-2-butenal-M(dimer), 1-octen-3-ol, butyl acetate(dimer), ethyl 3-methylbutanoate, and 2-pentylfuran were the markers that distinguished the volatiles in S. rugosoannulata cultivated with different groups of raw substrate materials.