Volume 18 Issue 3

The durability of engineered wood products (EWPs) is a parameter yet to be fully investigated and understood. This is specifically important for mass timber structures and cross-laminated timber (CLT) panels. The effect of termites and scale of damage on radiata pine sawn boards have been previously investigated. However, the effects of glue line and the layered structure of CLT exposed to termite feeding in the field in Australia have not been studied. A total of 420 CLT specimens with different exposed faces and layer arrangements were exposed to termite attack in the field. Microcomputer tomography and vibration analysis were used to assess sample conditions before and after 20 weeks exposure. The observed changes showed damage patterns within samples where a glue line and different growth ring patterns were present. The termites created continuous damage along the longitudinal cells through the length and width of the samples. The 3D data showed that the edge gap on the face of panels could potentially act as a pathway for termites entering the core or mid-layers of the panel. The vibration frequency values were lower for samples after the termite exposure. The vibration analysis results showed significant effects of sample direction exposed to termite attack, and percentage of mass loss had significant effects on internal friction and damping values determined.

Wood drying, such as boxed-heart square timber, often involves surface checks, which spoils the appearance of wood products and reduces their market value. Pretreatments are performed to avoid the surface checks, but detailed information about surface strain during timber drying remains unclear. In this study, surface strain detections were performed using two types of strain sensors (strain gauge and optical fiber strain sensor) to understand the surface dimensional changes during a series of pretreatments, consisting of steaming and high temperature and low humidity treatment. Simultaneous strain measurements based on the optical fiber sensor grasped the surface strain distributions in each lateral surface during timber drying; contraction behaviors were observed in the middle part of most surfaces in the early steaming stage, while one surface showed expansion. A remarkable expansion was detected in one surface during the high temperature and low humidity treatment, although most of the other surfaces showed gradual contraction behaviors. It was also discovered that the above detected behaviors were gradually reduced with the progress of each pretreatment.

This study investigated the optimal yeast strains for producing single cell protein based on waste sugar beet pulp (SBP) under various biomass loads. All tested strains were capable of growing on the waste biomass. Candida utilis and Saccharomyces cerevisiae Ethanol Red produced the greatest increase in protein on fresh SBP (ΔN 1.84%). Scheffersomyces stipitis (ΔN 2.27%) provided the highest increase on dried SBP. All tested strains showed significant assimilation of nitrogenous compounds. Based on the crude fiber content after fermentation, the largest reduction in fiber occurred with Candida utilis R6 (10.5%) on fresh SBP, and Yarrowia lipolytica (13.1%) on dried SBP. These results demonstrate the potential of SBP as a substrate for the production of single cell protein and highlight the importance of selecting the appropriate strains to optimize the process.

The proportions and constituents of the essential oils of flowers and leaves of Primula veris subsp. columnae were determined, and the antioxidant and the antimicrobial (antibacterial and antifungal) properties of their methanol extracts were investigated. Percentage ratios and main components of the Primula veris subsp. columnae plant, which grows naturally, were detected by extracting flower and leaf volatile oils. The components of the volatile oil were identified with Gas Chromatography Mass Detector-Flame Ionization Detector (GC-MS/FID). A total of 62 compounds were identified in flower volatile oil, and methyl 4-methoxysalicylate (37.1%) was determined as the main compound. While defining the structure of 50 compounds in leaf essential oil, linoleic acid (40.1%) was established as the main compound. As the result of the extraction of flowers and leaves with methanol, the extractive substance was obtained as 34.5% in flowers and as 28.8% in leaves. Methanol extraction and the antioxidant properties of the Primula veris subsp. columnae plant were quite high. In the antifungal and antibacterial activity test conducted on the volatile oils and methanol extracts of flowers and leaves of the Primula veris subsp. columnae species, only flower volatile oil showed weak inhibition properties.

Pinewood sawdust was pyrolyzed to create a micro-nanocarbon. The adsorbent’s particle size was reduced during a ball milling procedure to improve the surface area and encourage porosity growth. The synergistic effects of micro-nano-adsorbent-reinforced poly(lactic acid) (PLA) composites were investigated by analyzing the efficiency of the rheological process. The properties of the prepared composites also were examined using various characterization tests, including tensile and hardness tests, crystallinity tests, elemental composition, and plasticity behavior tests. Therefore, in-depth investigations and comparisons were also carried out to confirm the created composites’ efficacy compared to other outcomes.

Chip size distribution is important in kraft pulping, as it affects chemical use, quality, and yield in pulp production. Pinus taeda logs with two storage periods (0 and 2 weeks) and two log lengths (2.4 and 7.0 m) were processed with a disc chipper. Logs stored for two weeks produced chips with 7% less moisture than logs with no storage period. The storage period significantly influenced the quantities of overthick, accept, pin, and fines classes. Logs stored for two weeks produced 1.7% more overthick, 3.8% more pin, and 1.1% fines than logs with no stocking period. Consequently, the amount of accept produced was 6.2% higher for chips from  processing freshly harvested logs. Log length influenced the produced quantities of oversize, overthick, and accept. Logs with a length of 2.4 m produced chips with 1.4% more oversize, 2.5% more overthick, and 4.6% less accept, compared to 7.0 m logs. Thus, it was concluded that Pinus taeda logs with shorter storage periods and longer lengths generate more chips in the “accept” class.

One of the best and most affordable ways to remove harmful metals from water is by adsorption. This study investigated the efficiency of guinea fowl (Numida meleagris) eggshells as a low-cost adsorbent for cadmium (Cd) and nickel (Ni) removal from landfill leachate. In replicas, 100 mL wastewater was added to each of the weighed adsorbent dosages (1 g, 1.5 g, 2 g, 2.5 g, 3.0 g, and 3.5 g) in a flat-bottom flask and agitated for 60 minutes at pH of 7.82 and temperature 24 °C. The adsorption efficacy of cadmium and nickel by guinea fowl eggshells were 90.5% to 96.5% and 96.1% to 99.3%, respectively. The maximum adsorption capacity of cadmium was 4.89 × 10^-2 mg/g and an adsorption equilibrium (K_L) 22.74 mg/L. The Langmuir isotherm model was better fitted to the results of the experiment than the Freundlich isotherm model.

Spirulina platensis has roles in biotechnological product advancement due to its safety for humans and animals. Analysis of S. platensis extract by high-performance liquid chromatography reflected the presence of 14 phenolic and flavonoid compounds with different concentrations such as ellagic acid (333 µg/g), gallic acid (294 µg/g), methyl gallate (147 µg/g), naringenin (144 µg/g), and chlorogenic acid (142 µg/g). The isolated Aspergillus flavus from silage of maize was tested to evaluate the effect of S. platensis extract on aflatoxins B1, B2, G1, and G2 production. The treated silage with S. platensis extract showed the presence of 37±0.33 ppb, 0.59±0.16 ppb, 0.26±0.22 ppb, and 0.21±0.18 ppb compared to un-treated silage that showed 3.14±0.15 ppb, 0.81±0.08 ppb, 0.46±0.05 ppb, and 0.26±0.23 ppb aflatoxins of B1, B2, G1, and G2. These results were shown on the 10^th day of incubation. On the 15^th day of incubation, the treated silage showed less mycotoxins than un-treated silage. At different incubation periods, glucosamine was estimated as a growth development biomarker. The content of glucosamine was inhibited as a result of the effect of S. platensis extract on fungus growth with 53.71%, 49.19%, 47.84%, 38.47%, and 35.72% inhibition on the 3^rd, 6^th, 9^th, 12^th, and 15^th day.

This study optimized the salt free reactive dyeing process using the Taguchi approach. Dyeing of cotton fabric with reactive dyes is popular because of its bright and brilliant color in various shade ranges. Cationization with ALBAFIX-WFF and the dyeing process on cotton fabric was carried out using the exhaust method. To determine the optimum process conditions, two types of multiple characteristic parameters, including the single characteristic value conversion method and the process maximization method, were used on the basis of color strength (K/S) and wash fastness. The single characteristic value conversion method confirmed that the optimum process condition was a cationization temperature of 40 °C and a dyeing pH of 11. Most importantly, the optimal conditions were confirmed by the process maximization method as a concentration of ALBAFIX-WFF 30 g/L, cationization temperature at 80 °C, dyeing pH 12, and material-to-liquor ratio (M:L) of 1:5.  More suitable dyeing properties are also achieved by the process maximization method.

This study aimed to model carbon footprint, carbon dioxide sequestration, and emissions from kenaf cultivation as well as utilization of core and bast as biomaterials in the automotive industries and their environmental implications. It also considers the selection of suitable processing methods to improve the environmental performance of automotive parts. The data were obtained from three areas, and each area was divided into three cultivated sub areas for the carbon footprint model. Data regarding the conversion of kenaf to fibre when using kenaf high decorticator machines were provided from Kenaf Processing and Marketing Centre (CMPC) in Malaysia. The results showed that the total estimated quantity of carbon footprint of kenaf cultivation in the studied areas as well as the farms was about 0.750 tonne CO₂/tonne. In addition, the total estimated quantity of carbon sequestration of automotive components in the studied states       as well as the district was approximately 180,000 tonne CO₂/tonne/hectare/year in addition to carbon sequestered by soil in hectare of cultivated kenaf. The practices of kenaf cultivation, processing, and utilization into automotive components is essential for the environment and will assist in the mitigation of climate change risks.