Research Articles

A novel method for forming composite materials was investigated by incorporating activated carbon powder (ACP) as a reinforcing agent within a polylactic acid (PLA) matrix, utilizing the hand layup fabrication technique. The composite materials were synthesized by varying the weight percentages of the matrix and reinforcements, encompassing pure PLA as well as ratios of 90:10, 80:20, 70:30, 60:40, and 50:50. PLA is recognized for its biocompatibility and favorable thermomechanical properties, similar to conventional plastics. The incorporation of activated carbon powder, known for its remarkable aspect ratio, proved highly advantageous, yielding exceptional mechanical properties. Analysis revealed that the composite with a ratio of 90:10 wt% of carbon powder to PLA demonstrated significant improvements in tensile strength (26.8%), flexural strength (26.37%), impact strength (61.1%), compression strength (25%), and hardness (45.8%). Additionally, thermal analysis showed that the 90:10 wt% composite exhibited minimal weight loss and maximum heat flow sustainability at approximately 600 °C compared to other composite combinations. Morphological examination using field emission scanning electron microscopy unveiled a uniform distribution of activated carbon powder reinforcement within the matrix, actively contributing to the enhanced mechanical properties of the composite.

Nocardiopsis sp. strain LC-9 was isolated from freshwater sediments and explored for its varied bioactive traits. Initially, ethyl acetate extract of strain LC-9 at varied concentrations showed pronounced antibacterial activities. After column chromatography, fraction F2 and F3 of the extract were identified as prominent fractions in terms of antimicrobial activities with low minimum inhibitory concentration values. Antioxidant activities of fraction F2 and F3 revealed remarkable scavenging of free radicals with low IC₅₀ values (DPPH – 417.86 ± 0.24 μg/mL, ABTS – 431.6 ± 0.90 μg/mL, and FRAP – 404.36 ± 0.18 μg/mL). Fractions F2 and F3 were further characterized by UV spectrum, Fourier transform infrared spectroscopy, nuclear magnetic resonance, and liquid chromatography-mass spectrometry, and were identified as Antimycin A and 4-hydroxybenzoic acid. The compounds were further tested for anticancer activity against MCF-7 cells. The MTT assay showed reduced viability of MCF-7 cells with an increase in concentration of compounds. The IC₅₀ values for Antimycin A and 4-hydroxybenzoic acid were 9.6 ± 0.7 μg/mL and 20.8 ± 0.4 μg/mL, respectively. Staining techniques confirmed the apoptosis mechanism. Finally, molecular docking (against targeted proteins of bacteria, fungus, and cancer cells) and molecular dynamics confirmed the pharmaceutical efficacy of the purified compounds.

This study investigated the nutritional components of Castanopsis hystrix seeds and evaluated their potential commercial value, regarding multi-function management of C. hystrix plantations. The following nutritional components of Castanopsis hystrix seeds were determined according to national standards: starch, fat, protein, reducing sugars, and amino acids.  The chemical composition of their 50% benzene-alcohol(v/v) extracts was analyzed by GC-MS. Results showed that the contents of water, starch, fat, protein, and reducing sugar in the seeds were 36.08%, 68.11 g/100g, 0.3 g/100g, 3.98 g/100g, and 0.75 g/100g, respectively. The total amino acid content in the seeds is 3.42 g/100g, containing 16 kinds of amino acids, with 8 essential amino acids, which amount to 1.09g/100g. The amino acid SRC value was 84.02, indicating high nutritional value. A total of 26 compounds were identified in the extract of these seeds, with the highest content of aldehydes. The main compounds were 5-hydroxymethylfurfural (23.37%), melezitose (15.88%), palmitic acid (9.04%), and stearic acid (5.23%). The above analysis indicates that Castanopsis hystrix seeds have high nutritional value, as well as potential antioxidant and anti-tumor properties, which may have the potential to be used in food and medicine fields, with broad application prospects.

Hemicellulose is a renewable and environmentally friendly biomass polysaccharide. However, because of the low polymerization degree, conventional hemicellulose-based hydrogels often have poor mechanical properties, severely restricting their potential applications. This study involved preparation of a novel high-strength conductive hemicellulose-based composite hydrogel, modulated by a Na₂SO₄ solution. The hydrogel matrix with a physicochemical double cross-linking structure was created by adding polyvinyl alcohol to the chemically crosslinked networks of gelatin and dialdehyde xylan (DAX) to improve the enhancing effect. After being soaked in a 1 M Na₂SO₄ solution for 24 h, the composite hydrogel’s network structure was thicker, as revealed by scanning electron microscopy. Its tensile breaking strength (3.02 MPa) and elongation (330.95%) were much higher than those prior to the treatment. Energy dispersive spectroscopy and X-ray diffraction confirmed that the composite hydrogel had a considerable amount of Na⁺ and SO₄^2- uniformly dispersed throughout. Additionally, the ionic conductivity of the composite hydrogel was measured at 5.4 × 10^-3 S/m, indicating a potential use in the field of super-capacitors.

Willow wood furniture has become one of the most popular types of wood furniture in the Chinese furniture market. Research was undertaken to solve the pain points of product design and meet the requirements of green development. Firstly, the Kano model was used to classify user requirements. Secondly, the Analytic Hierarchy Process was used to calculate each design factors’ comprehensive weights, ensuring consistency between the design objectives and user requirements. Thirdly, the TRIZ contradiction matrix was used to identify and solve engineering difficulties in the design process. During the design process, the Kano-AHP-TRIZ was combined to realize a scientific design strategy that combines qualitative and quantitative approaches. The results showed that the design scheme of willow furniture based on user requirements had consistency, matching, and effectiveness with the furniture market development trend, which makes the furniture design process more scientific and rigorous. It also provided a new research perspective and design strategy for the innovative development of the furniture industry.

The effects of laboratory beating on unbleached regular grade pine kraft pulp (UPKP), pre-treated with commercial cellulase/hemicellulase enzymatic preparation (C/HEP) were assessed using degrees of Schopper-Riegler (°SR) and fibre-quality numbers (FQN). The tests showed a significant increase in the °SR (used in papermaking laboratories and industry to assess the degree of beating) of the UPKP after its enzymatic pre-treatment in the amount of 0.25 to 5.0 mL/kg of pulp and beating. However, only a several percent reduction of beating time was observed when the effect of this pretreatment of pulp on the speed of its beating was determined using another method. The treatment of the pulp selected for research with C/HEP before beating negatively influenced its strength properties after this process. The results correlated well with the most important basic fiber properties from the standpoint of papermaking.

Mechanical, thermal, and water absorption properties of banana fiber and sisal fiber-reinforced epoxy biocomposites were evaluated with and without cashew nut shell (CNS) filler, either separately, or as hybrid biocomposites. Bidirectional woven mats were used to make composites by compression molding. The CNS filler content was 5% to 10%. Adding CNS filler of up to 5% improved the mechanical and thermal properties. Further increases in filler content above the threshold value diminished their mechanical properties due to poor dispersion and increased porosity. The maximum tensile and flexural strength were found as 43 and 92 MPa. The highest impact strength was obtained with the hybrid biocomposites with 5% filler. This was attributed to the toughening effect of phenolic compounds in the CNS. In addition, the thermal stability of the biocomposites was influenced by filler content. The biocomposites exhibited varying water absorption capacities as the filler content increased with the water uptake. Scanning electron microscopy (SEM) images showed the microsurface of the fractured samples and their interfacial bonding, fiber pull-out, and fracture. However, increasing filler content in the biocomposite reduced the filler pull-out and led to fiber breakage.

In the production of wood fuel pellets, starch is frequently used as an additive to enhance bonding and durability. This study investigated the effectiveness of four different kinds of starches as additives, each at a concentration of 5% (dry basis), when combined with sawdust from Scots pine (Pinus sylvestris). The starches tested included plain wheat flour, hydrothermally treated wheat starch, wheat starch with amylose-like properties, and nearly pure amylopectin obtained from waxy rice flour. All pellets were produced at a die temperature of 100 °C using a Single Pellet Press, with varying moisture contents of 5%, 8%, 11%, and 14% (wet basis). The pellets were evaluated for compression work, back pressure, physical density, hardness, and moisture content. Additionally, chemical bonding was assessed using FT-IR spectroscopy. Compression energy was found to be influenced by moisture content, irrespective of starch utilization, and it decreased with increasing moisture levels, especially between 5 to 8% (wb). The inclusion of starch led to notably higher pellet hardness, with amylose yielding the hardest pellets, 34±3 kg when the moisture content was 11%. Based on this study, it is recommended to use hydrothermally treated wheat flour, as it consistently produced high-quality pellets.

The extraction methods used to obtain natural products face some problems, such as solvent toxicity, high extraction time, and low yields. Supercritical carbon dioxide fluid extraction (SFE-CO₂) is an encouraging extraction system for obtaining high-yield of natural extracts. In this work, Schinus terebinthifolia fruits were extracted via SFE-CO₂ using two conditions: A (static extraction) (SE) for 15 min, followed by dynamic extraction (DE) for 45 min, and B (without SE but with DE for 60 min). The extract yield was 0.205 g and 0.236 g via condition A and B, respectively. High-performance liquid chromatography assessment revealed the occurrence of several constituents with high quantities in the extract at condition B. The well diffusion test showed inhibition of 26 ± 0.1, 25 ± 0.2, 29 ± 0.1, 33 ± 0.2, 27 ± 0.1, and 8.0 ± 0.1 mm zones using the extract at condition B, while at condition A there were low inhibition zones towards Staphylococcus aureus, Pseudomonas areginosa, Bacillus subtilis, Escherichia coli, Candida albicans, and Aspergillus niger, correspondingly. Lipase (obesity stimulant) and butyrylcholinesterase (Alzheimer stimulant) were inhibited by the extract at condition B with IC₅₀ quantities of 27.03 and 4.83 μg/mL, while it was 37.45 and 17.57 μg/mL, respectively at condition A.

The US Pulp and Paper (P&P) industry heavily relies on fossil sources, with lime kiln operations posing a significant challenge for achieving zero on-site fossil emissions. This study assesses the greenhouse gas (GHG) reduction potential and costs associated with alternative fuels in lime kiln operations for linerboard production. Various options, including bio-based fuels including pulverized biomass, gasification of biomass, crude tall oil, bio-methanol, and traditional fuels such as fuel oil and petcoke, were analyzed through detailed process simulations and Life Cycle Assessment. Results indicate that per ton of product, 2,789 kg of CO₂-eq is emitted, with 69% being biogenic CO₂ and 31% fossil CO2-eq. Notably, replacing the natural gas boiler with a biomass boiler reduces Global Warming Potential (GWP) by 41%, while switching lime kiln fuel to biofuels achieves a 5.5% reduction. Combining a biomass boiler with pulverized biomass fuel use in the lime kiln yields a substantial 93.1% reduction in Scope 1 and 2 emissions, at a cost of $76/ton of CO₂-eq avoided.