Volume 16 Issue 2

There are differences in the extracellular enzymes produced from species of wood-rotting fungi and their activity due to variation in nutritional conditions such as carbon sources and nitrogen sources, as well as environmental conditions such as incubation temperature and pH. In this study, to determine the methods to promote the secretion of especially cellulase with high activity among the extracellular enzymes of wood-damaging fungi, the optimal nutrient sources and incubation conditions for the production of cellulase with high activity were investigated using response surface methodology based on a broth culture from Acanthophysium sp. KMF001, a novel strain of wood-damaging fungus. The nutrient sources that were optimal for the cellulase production with high activity from Acanthophysium sp. KMF001 were cellulose as a carbon source and tryptone:yeast extract (7:3) as a nitrogen source. The optimal incubation conditions were a temperature of 30 °C and a pH of 6. The optimal concentrations of carbon and nitrogen sources were cellulose at 31.1 g∙L-1 and tryptone:yeast extract (7:3) at 15 g∙L-1, with pH of 5.9.

A new method for producing biomass seedling trays with cow manure was developed based on heating to above the glass transition point of the lignin in cow dung. The maize seedling tray, manufactured through heat compression molding, could potentially meet the demand for transplanting maize seedlings. A scanning electron microscope and universal testing machine were used to compare the changes in the internal structure and mechanical properties of the seedling tray before and after the seeding period through a compression molding technique at normal temperature before seeding and a heat compression molding technique after seeding. The results showed that the strength of the seedling tray was mainly derived from the mechanical setting force of the fiber laminated in the seedling tray. Meanwhile, the moisture in the seedling tray hindered the lignin from filling in the gaps between the stem fibers in cow manure, as well as it reduced the protective effect of lignin on the laminated inlay structure of the stem fibers in cow manure. Therefore, under the premise that the material could be completely filled in the mold, the study concluded that a lower moisture content resulted in better strength and water resistance of the seedling tray. As such, this study provides an idea for the functional utilization of cow manure.

The biometric, density, and microscopic features of Parrotia persica species were investigated in this work. Three completely healthy P. persica trees were randomly felled. Three discs of 5 cm thickness were cut at three height levels (at breast height, 3 m, and 4.5 m) of each stem. The test specimens were sequentially taken from pith to bark. The biometric characteristics of the fiber and their density were analyzed. The microscopic features were studied according to the IAWA List of Hardwoods. It was found that all biometric factors of P. persica were decreased with increasing tree height from base to top. In contrast, these factors were also increased with the increase of distance from the pith toward the bark. Oven-dry density and basic density were decreased with an increase in the height along the tree stem. However, in the transverse direction, oven-dry density and basic density were increased from pith to bark. The anatomical study indicated that P. persica is a diffuse-porous hardwood that has distinct growth ring boundaries, heterogeneous rays, scalariform perforation, and alternative intervessel pits.

Desethyl-atrazine (DEA) is a metabolite of atrazine that exerts a considerable influence on the environment. In this study, tall fescue biochar was prepared by pyrolysis at 500 °C, and batch experiments were conducted to explore its effect on the adsorption behavior of DEA in red soil, brown soil, and black soil. The addition of biochar increased the equilibrium amount of DEA adsorption for the three soil types. A pseudo-second-order kinetic model most closely fit the DEA adsorption kinetics of the three soils with and without biochar, with a determination coefficient (R2) of 0.962 to 0.999. The isothermal DEA adsorption process of soils with and without biochar was optimally described by the Freundlich and Langmuir isothermal adsorption models with R2 values of 0.98 and above. The DEA adsorption process in the pristine soil involved an exothermic reaction, which became an endothermic reaction after the addition of biochar. Partitioning was dominant throughout the entire DEA adsorption process of the three pristine soils. Conversely, in soils with biochar, surface adsorption represented a greater contribution toward DEA adsorption under conditions of low equilibrium concentration. The overall results revealed that the tall fescue biochar was an effective adsorbent for DEA polluted soil.

The anatomical features of three valuable commercial Gigantochloa bamboo species growing in Indonesia, including G. pseudoarundinacea, G. apus, and G. atroviolacea, were investigated by optical microscopy. The relative crystallinity and crystalline width of the culm of the bamboo species were examined by an X-ray diffraction method. These species contained vascular bundle of type III. Vascular bundle density was higher in the outer part of bamboo culm than in the inner. Fiber portion decreased from the outer part to the inner part and vice versa for the parenchyma and vessel portions. Fiber length of all species was higher in the outer part than the inner part of the culm. There was a significant difference in the fiber percentage between the bamboo species. Significant differences were also found in vessel diameter and parenchyma cell dimensions among the bamboo species. There was a slight difference in the crystalline properties between the outer and inner parts of the culm and among the bamboo species. All parameters showed a variation in the radial direction of the three bamboo culm but did not show a consistent tendency along the vertical direction.

Many engineering designs focus on the production of durable, ergonomic, and economical new materials. In today’s world where natural resources are rapidly decreasing, recycling waste materials is of great importance. As a result of the bending test, the sample’s return to its original dimensions shows the plastic feature of the material. It was observed that the tensile strength can be increased if the speed of the injection machine is well adjusted in the production of tensile strength testing samples. There was an increase in the screw tensile strength of the samples and the joint hardness strength. Thermogravimetric analysis (TGA) showed that the reference samples were completely crumbled around 480 °C, and it was observed that only quartz remained from the input materials. Differential scanning calorimetry (DSC) showed that the peak point in the reference sample was at the heat flow rate of 29 m/W, while it was 18 to 19 m/W in the doped groups. Melting temperature was observed in the range of 125 to 135 °C in all groups. The mechanical properties of the quartz-substituted samples increased compared to the reference sample. It was observed that the quartz and wood powder contained in the mixture worked in harmony.

The industrial utilization of straw from the field is an important way to achieve its comprehensive utilization. Construction of an efficient collection system is the premise and foundation for the efficient utilization of straw resources. It has become an urgent problem to reduce the cost of storage and transportation of straw from the field. In order to construct an indexing system and method of regional suitability evaluation of straw storage and transportation technology model, a model based on regional suitability criteria for straw storage and transportation technology has been constructed by using literature analysis. The evaluation method of the straw storage and transportation technology model is briefly discussed. This method provides a quantifiable basis for screening, evaluation, integration, and popularization of the straw storage and transportation technology model.

This study was conducted to provide foundational anatomical information of three infrequently used wood species growing in tropical areas. Three species of the genus Syzygium, namely the clove tree, kupa, and spicate eugenia, were selected. The representative anatomical features of these species were classified using the International Association of Wood Anatomists (IAWA) anatomical feature list. The representative anatomical features of the clove tree included the distribution of small vessels with tangential diameters of approximately 60 µm in cross-surface, a dense spacing of vessels, the axial parenchyma in narrow bands or lines up to three cells wide, and the body ray cells procumbent with over four rows of upright and/or square marginal cells. The kupa showed axial parenchyma confluent and the body ray cells were procumbent with over four rows of upright and/or square marginal cells. In the spicate eugenia, the axial parenchyma was diffused in aggregate with exclusively uniseriate rays and the body ray cells were procumbent with one row of upright and/or square marginal cells. These three species were easily identified by optical microscopy via the anatomical features of the woods.

Labour productivity is one of the key factors determining the wood-based industry development and competitiveness. This study assessed the importance of human resources and labour productivity in the furniture sector in the European Union (EU) countries. A cluster analysis and multivariate linear ordering analysis were conducted. The EU15, especially Germany, Denmark, and United Kingdom, demonstrate a higher labour productivity and offer even four-fold higher wages to the employees than some EU13 countries. It results in a relatively high share of labour costs in the production. However, in some countries of Central and Eastern Europe, the importance of furniture production for the national economy and the job market was high. To maintain the sustainable development of the EU market, decreasing the regional differences is essential. Additionally, the existing competitive advantage of selected EU13 countries resulting from relatively low labour costs can be insufficient to maintain the current rate of production growth and furniture exports. The results of the study provide a precious source of information for entrepreneurs, managers, and government. They will help the production enterprises identify the areas to be made more efficient by taking important decisions to enhance competitiveness and design the future path of sustainable furniture sector development.

Usage of cellulosic nanofibers, starch-nanocellulose, and polyacrylamide-nanocellulose hybrid systems were investigated for the replacement of imported long bleached kraft fibers in the production of durable papers. In this study, imported softwood kraft pulp was added to cotton pulp at four levels. Nanofibrillated cellulose (NFC) prepared from chemimechanical pulp was added to cotton pulp at a 5% level with optional 1% cationic starch or 0.1% cationic polyacrylamide. Comparative tests were done without NFC at three levels of either cationic starch or cationic polyacrylamide. For each condition, 80 gm-2 handsheets were made, and the physical, mechanical, and optical properties of the paper were compared. The results showed that increases of NFC yielded higher surface smoothness, tensile strength, resistance to bursting, tearing energy, folding endurance, yellowness, and opacity. It also reduced brightness and porosity whether added singly or in combination with cationic starch or polyacrylamide. Increasing cationic starch also increased surface smoothness, tensile strength, resistance to bursting, and folding endurance, but paper opacity was reduced. The field emission-scanning electron microscopy results showed that increased NFC reduced porosity, the paper surface became smoother, and the pores were relatively filled. Finally, the combined treatment of 5% NFC and 1% cationic starch is introduced as a suitable combination.