Research Articles

Nutrient-rich raw bamboo materials can be infected by mildew when exposed to water or high humid environments. This not only affects the appearance of bamboo products, but it also contributes to respiratory diseases. Herein, four anti-mildew agents, i.e., boric acid, copper sulphate, alumina phosphate sol, and alumina silicate sol, were used to evaluate their anti-mildew performances. The results showed that the adequate anti-mold concentrations of boron and copper were 2% and 0.7%, respectively. The optimum mass ratio of aluminum phosphate sol and silicone aluminum sol were 1 to 1 (2% phosphoric acid addition) and 10 to 1 (aluminum salt addition was 1.5%). There were significant differences in the prevention and treatment effects of different mold inhibitors on mold and discoloration bacteria. The efficacies order of the anti-mildew property was as follows: copper sulphate > alumina silicate sol > boric acid > alumina phosphate sol. In addition, the order for stain fungi resistance was: boric acid > alumina phosphate sol > alumina silicate sol > copper sulphate. The selected anti-mildew agents showed promising application requirements as an active ingredient in bamboo preservative systems.

As a strategic new material with excellent performance, carbon fiber has attracted much attention in the wood structure industry. In this paper, the test modal and computational modal analysis methods are used to study the mode shape and modal parameters of carbon fiber board, calculate the elastic constants, i.e., the elastic modulus, shear modulus, and Poisson’s ratio, and analyze the coupling of the results. The conclusions show that the numerical results of the mode shape and elastic constants of the carbon fiber board obtained via the computational modal and test modal analysis are highly coupled. The first-order bending and first-order torsional modes of the carbon fiber board obtained via the two analysis methods are consistent, and the frequency error rate is less than 5%. The error rates of the elastic modulus and shear modulus are 0.7% and 7.8%, respectively. In addition, the research is conducive to strengthening the work of finite element computational modal analysis, and better promoting the application of non-destructive testing and quality grading of carbon fiber board. The above-mentioned optimization design work for improving the dynamic characteristics of carbon fiber board, and further research on the detection and optimization of the performance when the carbon fiber material is combined with wood, also has engineering application value for promoting the faster development of the wood structure market.

Six hybrid models of cellulose amorphous region and water molecules were established by using a molecular dynamics software to simulate changes of cellulose and water molecules during bamboo hydrothermal treatment. The results indicated that in the range of hydrothermal treatment temperature of bamboo from 150 to 240 °C, the diffusion coefficient of water molecules increased with the increase of temperature, conducive to the processing efficiency of hydrothermal treatment. The mean square displacement (MSD) of the bamboo cellulose chain increased with the increase of temperature, not conducive to the thermal stability of cellulose. The energy change of the system predicts that a higher hydrothermal treatment temperature will result in faster material aging degradation. The comprehensive analysis of mechanical parameters showed that when the hydrothermal treatment temperature did not exceed 180 °C, bamboo cellulose had better plasticity and toughness.

Micro-solid oxide fuel cells (SOFC) sensors prepared via depositing a thin film BYCF (10 wt% [Ba0.95FeY0.05O2.8] + 90 wt% [Co2O3]) – GDC20 (Gd0.20Ce0.80O1.95) cathode and NiO-GDC20 (Gd0.20Ce0.80O1.95) anode on a GDC20 electrolyte layer were operated at 800 °C. The structure, which receives only biogas, was formed into 15-mm pellets with only one side for detecting methane (CH4). The detection of 40% to 99.99% CH4 provided a high level of accuracy compared with 10% to 30% CH4. The biogas (60% CH4) from the Oil Palm Industry and Rubber Cooperative Fund, Thailand, increased remarkably at voltage levels of 20 to 21 mV. The electrical signal from the micro-SOFC sensor corresponded to the quantity of CH4, with the chemical reaction of the dry reforming activities (NiO and Co3O4) highly catalyzed and transformed from CH4 to H2, thus generating electrons. It was concluded that the micro-SOFC sensor is suitable for detecting methane measurements at intermediate temperatures, with the ceramic structure offering low degradation compared with metal sensors.

The National Timber Industry Plan was the first major dedicated policy framework for the wood products industry in Malaysia. This plan aimed to transform the industry into a high value-added products manufacturer and exporter, with a targeted export value of USD 13 billion in 2020. Unfortunately, this target was revised downwards in 2017 due to stagnating growth; in 2020, wood products export was valued at USD 5.43 billion. A survey of 914 different wood products manufacturers, involving sawmillers, molding, furniture, and joinery manufacturers, were conducted to examine the constraints faced, and the weaknesses of the policy framework that hampered its intended objectives. The results revealed that the policy framework did not have much impact on transforming the industry, and its growth continued to be fueled by incremental factor inputs, rather than by productivity gains. Uncertainty with the policy framework, especially with addressing raw materials supply and workforce, were highlighted as the two most important constraints faced. In essence, the outcomes suggest that business confidence, associated with industrial growth factors, are the prerequisite for the policy framework to succeed, and if confidence falters, it will adversely affect the targeted outcome of the policy.

Lumber manufacturing facilities generate large amounts of wood residues as a by-product of processing. In this study, the torrefaction characteristics of the Cryptomeria japonica and Acacia confusa residues were evaluated and compared to microcrystalline cellulose. The torrefied products also were analyzed. The results showed that the higher heating value (HHV) of the C. japonica and A. confusa residues increased to 5,993 and 5,576 kcal/kg after 20 min of torrefaction at 310 °C, which was higher than the microcrystalline cellulose (4,340 kcal/kg). The energy densification of the torrefied biomass could rise to 1.17 to 1.20 times higher than the raw biomass. The condensable gaseous product was an organic acid liquid. The liquid product consisted of some alkanes, alcohols, esters, and amides. The exothermic temperature would be reduced after torrefaction. Additionally, the thermal treatment of the biomass destroyed the cellulose crystals and reduced the cellulose crystallinity index. In order to reduce the usage of fossil fuels, the torrefied solid biomass could be mixed with coal in power plants directly.

The oil palm trunk contains great nutrients for plant growth, and its supporting cells are mostly parallel to the centerline. This study investigated the fabrication of a plantable bio-pot from 5 mm thick sheets of oil palm trunk. The effects of the three zones in the trunk (outer, middle, and inner) and the pressing mold temperature in the range from 160 °C to 200 °C on characteristics of a bio-pot were evaluated. The results demonstrated that the outer zone of an oil palm trunk with 200 °C molding temperature had the highest ultimate compression load, and the pot shape appeared stable after soaking in water for 24 h, showing 105% water absorption. The changes to oil palm trunk chemistry caused by elevated temperature contributed to the mechanical properties and improved durability. The oil palm trunk plantable bio-pots facilitated germination of chili and eggplant seeds. The leaf number, leaf greenness, plant height, and total dry biomass had no significant difference between using the oil palm trunk bio-pot and a plastic pot for a seedling of either of these plants.

As magnetic fillers, e.g., nanomagnetite, reduce the mechanical strength of produced magnetic papers, additives should be used. In this study, nanomagnetic papers were produced through an in-situ method by synthesizing magnetic cellulose fibers with kraft fibers and iron salts in a nitrogen atmosphere. Then, gluconic acid was added to improve the mechanical strength. The properties of nanomagnetic papers were investigated via different methods. The nanomagnetite particle size ranged from 1 to 84 nm. Scanning electron microscopy demonstrated the deposited nanomagnetite particles on the surface of the fibers. The saturation magnetization of the nanomagnetic papers treated with 0%, 1%, 2%, or 3% gluconic acid (per dry weight of the pulp) was 7.54, 5.64, 4.81, and 0.55 emu/g, respectively. The nanomagnetite particles loaded on the fibers decreased as the gluconic acid content was increased. The nanomagnetic papers exhibited superparamagnetic behavior. Elevation of the gluconic acid content caused an increased tensile and burst index, as well as a reduced tear index. It also led to augmented brightness and diminished opacity.

A successful conversion of lignocellulosic biomass into biofuel could be achieved through an ionic liquids (ILs)-pretreatment and an enzyme saccharification. In this study, the fungal strains with high cellulase productions were isolated and identified as Penicillium janthinellum FHH1 and P. oxalicum FLY4. A high cellulase production was obtained at pH 4.0 and 30 °C for P. janthinellum FHH1 with corn stalk and beef extract for 9 days and for P. janthinellum FHH1 with corn stalk and peptone for 7 days. A pH range between 4.0 to 6.0 and a temperature range from 55 °C to 60 °C were applicable for cellulase with high activities during hydrolysis. A high NaCl-stability and a relatively high ILs-stability were found for cellulase obtained from P. oxalicum FLY4. High yields of reducing sugar were obtained by enzymatic hydrolysis of the original corn stalk and ILs-pretreated corn stalk. P. oxalicum FLY4 has a great potential for ILs-assisted fungi in the degradation of lignocellulosic biomass into value-added products.

Small-to-medium scale softwood sawmills in the Copperbelt of Zambia are operating below 50% capacity. The timber supply is uncertain as demand continues to increase in tandem with economic activities and population growth. This study identified the financial, i.e., access to finance and operating costs, and non-financial, i.e., raw material, transport, skilled labor, and sawn timber recovery, as the limiting factors affecting performance. The authors benchmarked various financial ratios, i.e., gross profit margin, net profit margin, return on investment, return on capital employed, and working capital turnover, of the small-scale sawmills compiled from survey data with the average industry ratios. Raw material is the most limiting factor affecting profitability/success of small-scale sawmills. A Cobb-Douglas model demonstrated that sawn timber recovery depends on operator skills, particularly in non-automatic machinery, which are common. Strategies currently employed are value addition, multiple sourcing, equipment acquisition and modernization, and labor cost reduction. Measures proposed to enhance profitability are credit guarantee schemes, collaboration, tax reduction, lesser-used timber utilization, and timber auction floor.