Volume 19 Issue 3

Efficacies of plant metabolites are known to be dependent on their extraction methods. Yields and compositions of phytoconstituents in the extract were evaluated following supercritical fluid extraction (SFE) of Vitex agnus-castus leaves, static extraction times (SET) for 30 min, subsequently dynamic extraction time (DET) for 30 min (condition A) and SET for 0 min followed by DET for 60 min (condition B). The extract exposed to condition B gave an extraction yield of 0.169 g compared to 0.115 g for condition A. High-performance liquid chromatography analysis revealed compounds including cinnamic acid, kaempferol, ferulic acid, rutin, and caffeic acid, in high concentrations in the extract exposed to condition B. Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis, and Candida albicans were more affected by the condition B with 32 ± 0.1, 20 ± 0.2, 32 ± 0.2, 35 ± 0.2, and 40 ± 0.1 mm inhibition zones, respectively. Less MIC and MBC were noticed of the exposed extract to condition B than to condition A against C. albicans and bacteria. The IC₅₀ of the extract exposed to condition B was high against ovarian tumor cells. Presently the efficacy of the exposed extract to condition B for wound healing process was documented.

Rainforests, as invaluable natural resources, play a pivotal role globally, offering many ecosystem services such as recreation. This study aims to quantify the value of Brunei’s rainforest assets (specifically recreational areas and national parks) utilizing the Travel Cost Method (TCM), a prevalent approach for ascertaining the worth of natural sites. The tourism use of Brunei’s rainforests holds a high value, estimated at over $300,000 USD per square kilometer, which supports the argument for resource allocation towards their protection not only for ecological reasons but also for their recreational benefits. The authors posit that nature-based ecotourism can be a sustainable and protective mechanism for tropical rainforests. Practical recommendations for ecotourism include a minimalist approach to visitor regulation, limiting access to a small percentage of large recreational areas and national parks to protect flora and fauna, and possibly implementing entry or service fees.

The design of auditorium chairs can directly reflect the image of public spaces. At present, the development of public furniture is relatively slow compared to household and office furniture. The design of auditorium chairs on the market is severely homogenized, relying on past experience and lacking scientific guidance. In order to create a better indoor public activity environment for users, from the perspective of user needs, first of all, 21 user needs for auditorium chairs were obtained through semi-structured interviews. Then, the Kano model was used to determine the attribute positioning of each demand. Finally, the FAST method was used to transform user demands into functions, assisting in the design optimization of hall chairs and promoting the future development of public furniture. The results indicate that the design of auditorium chairs must meet safety and stability, and the comfort and rechargeability of the seats are the most important needs of users. In the future, the functional design of auditorium chairs also needs to consider intelligent applications. The study applies a Kano-FAST integration method to the design innovation of auditorium chairs, providing data support for the development of furniture enterprise auditorium chairs and promoting product upgrading and optimization.

Bonsai is a kind of classical art in China and Japan. The traditional method of bonsai shaping of miniature trees is technical and usually requires experienced horticulturists to successfully carry out the process. In order to let ordinary people feel the fun of bonsai shaping, this paper proposes a fast bonsai shaping method, i.e., by use of a plastic guiding mold with customized shape, which is processed by fused deposition 3D printing technology. The tree seedling is bundled onto the mold, and the shape of the mold guides the growth of the tree seedling, thus achieving the purpose of bonsai shaping. In order to further improve the bending properties of the bonsai guiding mold, this paper investigated the main 3D printing parameters of ABS filament. The results showed that with the decrease of printing speed, the increase of extrusion temperature, and the increase of hot bed temperature, the bending strength and elastic modulus of ABS specimens increased, and the bending properties was enhanced; the optimal printing speed was 50 mm/s, the extrusion temperature was 230 °C, and the hot bed temperature was 80 °C. The mechanical properties of the bonsai guiding mold manufactured based on the optimal process parameters were better, the print quality was higher, and it had high practical value.

The effects of the antioxidant, butylated hydroxytoluene (BHT), and the metal chelator, ethylenediaminetetraacetic acid (EDTA) in combination with cedarwood oil (CWO) were investigated for wood preservation against subterranean termites as well as two species of white-rot decay fungi and two species of brown-rot decay fungi. Vacuum pressure impregnation was used to treat wood blocks. Resistance of the treated wood test blocks was evaluated using a no-choice bioassay for termites and a soil bottle assay wood decay fungi. Eight treatments were tested: H₂O only; BHT only; EDTA only; BHT with EDTA; CWO only; CWO with EDTA; CWO with BHT; and CWO with BHT plus EDTA. For termites, the lowest percentage wood mass losses were for the EDTA, BHT, CWO, and CWO/EDTA treatments, all of which were statistically equivalent. Correspondingly, these treatments all had the highest termite mortalities at 100%. The four species of decay fungi were affected differently by the wood treatments; however, overall CWO and EDTA gave the best protection against wood mass loss. The addition of BHT did not decrease mass loss.

T-shaped mortise and tenon members are the main structure of traditional Chinese furniture. In this paper, the double-dovetail joint used for face-to-face joint of rubber wood (Hevea brasiliensis Muell. Arg) is transformed into a new type of double-dovetail joint and rounded double-dovetail joint for T-shaped members of point joint structure. The ultimate pull-out test and bending strength test were carried out on the two structures and three structures of oval mortise, round rod mortise and right angle mortise. The results show that the ultimate pull-out force of the round double-dovetail joint is 39% higher than that of the double-dovetail joint, and the bending resistance capacity is 8.9% higher, and the strength and stability are better than those of other split mortises and tenons, which proves that this structure can be used in actual production, and also proves that the mortise and tenon connected by the surface has the possibility of transforming into a point connection structure. The concave structure of the rounded double-dovetail joint makes the mortise and tenon fit well, the tenon squeezed tight, and a good bonding effect was achieved. This structure can also provide greater friction and resistance, delay rubber adhesive failure and improve the stability.

Fruit drop from pear trees causes serious losses in income. However, the application of plant bio-regulators improves the internal physiology of developing fruit by ensuring that they receive an adequate supply of water, nutrients, and other compounds necessary for their proper growth and development, which leads to improved size, quality, and ultimately better yield in a variety of fruit crops. This study investigated the foliar application of three plant growth regulators: CPPU at 10, 15, and 20 ppm, GA₃ at 25, 50, and 75 ppm and NAA at 25, 50, and 75 ppm. The pear trees were sprayed four times: before flowering, full bloom, after three weeks, and after six weeks. The results showed that the spray of GA₃ at 50 and 75 ppm gave the highest effect in increasing the shoot length, shoot thickness, leaf area, and leaf total chlorophyll. The spraying of NAA at 50 and 75 ppm was the best treatment in increasing the fruit set percentages, fruit yield, fruit weight, and fruit dimensions as well as the fruit content from soluble solids, and fruit sugars, while they reduced the fruit drop percentages comparing with the other applied treatments.

Preservative systems based on vegetable seed oils and natural waxes from renewable sources may confer protection to wood under exposure to various environmental conditions. These, as non-toxic substances, can form an environmentally friendly and efficient protective layer on the wood surfaces, with beneficial effects on their water resistance and dimensional stability. Thus, these natural coatings may hinder biodegradation of wood products to a certain degree. In present paper, softwood samples (from Abies alba fir tree species), prepared as dried discs (25 to 30 mm diameter, 8 to 10 mm thickness), were surface impregnated by dipping using vegetable oils, namely Asclepias syriaca seed oil, and soybean oil, respectively. Beeswax treatment was also applied for comparison purposes. Surface chemistry and morphology, biodegradation process under controlled and simulated natural conditions, and water sorption behavior of wood samples were investigated. Fourier Transform Infrared spectroscopy, X-ray diffraction, and scanning electron microscopy methods were used for investigation of surface changes in wood samples before and after impregnation with natural based products, as well as under biodegradation conditions in soil burial tests.

The escalating demand for polyurethane rigid foams (PURF) has resulted in a substantial increase in waste polyurethane products. In view of the difficulty in recycling waste PURF, this study introduces a novel mechanical recycling process that is cost-effective and features a straightforward fabrication process for producing PUW (waste PURF combined with wood veneers), which solves the problem of low strength products obtained from mechanical recycling of PU waste. Through investigation of the PURF (ground into particles before using) particle size, core layer density, the amount of resin and thickness, the optimal fabrication process was confirmed as follows: particles with the size of 1 to 3 mm as its core layer components, 0.9 g/cm³ as its core layer density, the addition of MDI to be 20 wt%, and 8 mm thickness of whole composite. The resulting PURF-based composite exhibited superior thermal insulation properties, mechanical strength, and sound insulation performance. The optimized PUW composite had a notably low thermal conductivity of 0.04126 W/(m·K), slightly higher than that of rock wool board (0.04 W/(m·K)). In terms of mechanical performance, the wet shear strength of the optimal PUW composite reached 0.61 MPa. Furthermore, the PUW composite exhibited relatively high sound insulation, particularly at high frequencies.

The effect of shredded waste office paper was considered when producing one-layered particleboard. Five different mixing ratios of shredded waste office paper/wood particles were used (0/100, 25/75, 50/50, 75/25, and 100/0) and two amounts of urea formaldehyde (UF) resin (10% and 15%). The boards were tested for their physical and mechanical properties, including modulus of elasticity (MOE), bending strength (MOR), and internal bond (IB) strength, in accordance with the European Norm (EN) standards. All properties of the boards were found to be improved via increasing the resin content. The 15% UF-bonded board with 100% wood particles had the highest MOR, whereas the board containing 100% wastepaper for 15% UF had the highest MOE. However, there was no statistical difference between the board types. Although increasing wastepaper content in the board negatively affected the IB, the usage of wastepaper up to 25% was shown to be acceptable as a raw material in the production of particleboard. None of the prepared boards met the EN 312 (1999) requirements for thickness swelling. The boards made from shredded waste office paper were more suitable for dry and indoor use.