Research Articles

The energy needed for the dewatering and drying of wet paper web represents around half of the energy consumption of papermaking processes. The present work examined whether the dewatering and drying of paper could be enhanced during a previous pulp drying process by pretreating the fibers with polyamide-epichlorohydrin (PAE). According to the hypothesis, the cured PAE restrains swelling and water absorption of water-wetted fibers by forming a fiber-bound, self-crosslinked polymer-network on the fiber surfaces. The hypothesis was tested by adding PAE to never-dried kraft pulp slurry followed by pulp thickening, drying, and final curing of the PAE-resin. After this, the PAE-treated fibers were dispersed in water, and their water retention values (WRV) and Shopper-Riegler values (^○SR) were measured. The PAE pretreatments notably decreased the fibers´ WRV and ^○SR, indicating improved water removal of paper web in the paper machine forming and drying section. Compared to chemical crosslinking pretreatments, which also can be used to decrease fibers WRV and ^○SR-value, a notable advantage of PAE-pretreatment is milder required curing conditions of the PAE, which makes implementation of the method easier in practice. Due to decreased fiber-to-fiber bonding capability, the PAE-treated specialty fibers could take advantage especially as a bulking aid of paperboard, tissue, and absorbent materials.

Ultraviolet (UV) radiation causes skin damage including oxidative stress, inflammation, and photoaging. Extremophile fermentation products have been found to effectively protect the skin from UV-induced damage. This study aimed to investigate the impact of acid-induced stress on the content of bioactive compounds, as well as the anti-inflammatory and anti-photoaging properties of sorghum fermentation by the extremophilic Monascus pilosus. The study compared acid-stress fermentation (ASF) of sorghum with conventional fermentation (CF) and examined differences in total phenolic content, antioxidant activity, and short-chain fatty acid levels. Using gas chromatography–mass spectrometry assay, the ASF sample had lower total phenolic content compared to CF, but significantly higher levels of short-chain fatty acids. Butyric acid was the predominant metabolite in the ASF sample, followed by propionic acid. The ASF sample exhibited superior protection for UV-irradiated human keratinocytes by inhibiting apoptosis, reducing ROS, and downregulating inflammatory mediators. It also decreased metalloproteinases expression levels, increased collagen and elastin production, and mitigated UV-induced photoaging. The effects of ASF samples were evaluated in volunteers, and the results confirmed the ASF sample’s effectiveness in ameliorating UV-induced skin symptoms, including pigmentation, redness, and wrinkles. These findings conclude that acid-stress enhances the anti-inflammatory and anti-photoaging capabilities of Monascus pilosus fermented sorghum.

The decision-making process of consumers regarding custom wardrobe furniture transcends product functionality to include the sensory experience, notably the tactile aspect. This study focuses on the tactile experience to assist consumers in evaluating the tactile feel of custom wardrobe finishes, such as cognitive fuzziness during the experience, the challenge of clearly describing the connection between touch sensation and the physical attributes of the custom wardrobe, and reducing communication costs between users and designers. The research first clarifies the hierarchical cognitive structure of the tactile sensation of custom wardrobe finishes, then explores the logical relationships between levels through linear regression models. Subsequently, a nonlinear relationship model between the “Physical Attributes Layer” and the “Tactile Sensation Layer” is constructed using a Backpropagation Neural Network, and the connection between the “Tactile Sensation Layer” and the “Comprehensive Evaluation Layer” is mapped through a multiple linear regression equation. This comprehensive evaluation system for the tactile feel of custom wardrobe finishes provides designers with a tool to optimize the tactile characteristics of products, thereby shortening the design iteration cycle and improving design precision. It also helps users better express their emotional needs in terms of tactile sensations, enhancing the connection between tactile experience and emotion.

This work was conducted using the PicoScope signal extraction procedure, which revealed remarkable insights regarding the belian wood and its application in Sarawak traditional ‘tar’ instrument. The ‘tar’ is a small drum made of wood and attached with goat skin. A hadrah performance is done with the sound of the blow of the ‘tar’ and reciting poems praising Allah and the Prophet Muhammad by a group of players called the hadrah group. The ‘tar’ from belian wood had the highest pitch at 180 Hz i.e., F3# compared with the ‘tar’ from menggeris wood, which had the pitch D3# and A2 that also highlighted their importance in the Western scale. The overtones are not integer multiples of the fundamental frequency except for second and third overtones from ‘tar’ C (F2/F0 = 3 and F3/F0 = 4). Using Adobe Audition for Time Frequency Analysis (TFA) recordings for the ‘tar’, the data collection method provided insightful information. The communal efforts of practitioners, who are frequently grouped together, perpetuate the cultural heritage of hadrah. Essentially, by offering a thorough grasp of the intricate melodic details woven in hadrah’s cultural fabric, this research adds to the genre’s continuing heritage.

Water contamination in rural Malaysian areas, mainly caused by logging activities leading to soil erosion and river pollution, presents a significant threat to water supplies. In response, a specialized activated carbon water filtering device was developed to target the absorption of organic molecules. The impact of compaction of activated carbon on water filtering efficiency was evaluated. Testing both compacted and uncompacted activated carbon filters with contaminated river water, the study utilized the Malaysia Department of Environment’s (DOE) water quality index (WQI) to assess filter effectiveness. The results revealed that water filtered through compacted activated carbon was clearer and less yellowish compared to the uncompacted counterpart. Moreover, the compacted filter showed higher dissolved oxygen levels, lower ammoniacal nitrogen levels, and a lower pH, resulting in a significantly higher WQI score of 80.4 compared to 78.8 for the uncompacted filter. Further analysis via an adsorption isotherm test demonstrated the superior ability of compacted activated carbon to absorb acetic acid, as evidenced by higher lines in the Freundlich isotherm model graphs. These findings emphasize the efficacy of compacted activated carbon in water filtration, advocating for its integration into filter construction to enhance water quality in rural regions.

Lignin, renowned for its abundance of hydroxyl groups, was utilized in three dimensions to fabricate a hydrogel matrix. In this study, the optimal conditions for the preparation of a lignin-crosslinked hydrogel and its potential for dye and antioxidant removal were investigated. The hydrogel was synthesized through a cross-linking reaction, with varying amounts of cross-linking agent (poly(ethylene glycol) diglycidyl ether) added to adjust for the lignin content. Chemical structure analysis of the lignin-crosslinked hydrogel was conducted using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, confirming successful hydrogel formation. Additionally, thermal analysis revealed an increase in the maximum thermal decomposition temperature with increasing cross-linker content. The lignin cross-linked hydrogel demonstrated a significantly higher swelling ability at pH 7 compared to pH 3. The dye adsorption capacity of the lignin-crosslinked hydrogel, which was evaluated using crystal violet (CV), showed a maximum adsorption capacity of 106 mg∙g^-1. The CV adsorption behavior followed Freundlich isotherms and pseudo-first-order kinetics. Moreover, the lignin-crosslinked hydrogel exhibited notable antioxidant activity, which was attributed to the phenolic hydroxyl groups of lignin macromolecules. Therefore, lignin-crosslinked hydrogels prepared using cross-linking agents have promising application potential in various fields.

Global regulations are guiding society towards more sustainable material solutions. This increasing awareness of the need for environmentally friendly alternatives has led to a greater emphasis on biocomposites, which combine natural fibers with bio-based polymers. This study investigates how bleached softwood pulp fibers (BSWPF) and unbleached softwood pulp fibers (UBSWPF) affect the characteristics of poly(lactic acid) (PLA)-based biocomposites. UBSWPF is a more cost-effective option because it is manufactured with less processing steps than BSWPF. However, it is largely unexplored as a reinforcement in biopolymers. Through investigating the mechanical, thermal, and morphological aspects of the biocomposites, this study showed that UBSWP increased the modulus and impact strength of the PLA biocomposites better than BSWPF. The impact strength, modulus, and tensile strength of PLA-BSWPF and PLA-UBSWPF improved as the fiber content increased. However, a decrease in tensile strength was seen at higher percentages of UBSWPF in PLA. Despite the decrease in tensile strength at higher UBSWPF concentrations, both types of fibers improved the mechanical properties of the biocomposites, demonstrating a potential sustainable reinforcing material for PLA biocomposites.

Mulch was prepared using composted sugarcane leaves, with polyvinyl alcohol and cationic starch as adhesives, through compression molding. The study aimed to investigate the effects of different adhesives on the mechanical properties, thermal oxidative degradation performance, and biodegradability of the covering materials. The results indicated that, when the adhesive dosage was consistent, cover material A, which utilized polyvinyl alcohol as the adhesive, exhibited higher tensile strength and elongation at break compared to cover material B, which employed a blend of polyvinyl alcohol and cationic starch. Specifically, at an adhesive dosage of 20%, cover material A achieved a tensile strength of 0.46 MPa and an elongation at break of 7.72%, representing the highest values among all experimental groups. There was minimal disparity in the thermal oxidative degradation performance between materials prepared with either adhesive; however, a higher quantity of adhesive led to decreased biodegradability performance. After being buried in soil for 120 days, the degradation exceeded 40% for both materials, resulting in loss of their original shape and strength properties. In conclusion, while sugarcane leaves-based biodegradable materials demonstrate favorable degradation performance, further enhancements are necessary to improve their mechanical properties. These materials have potential applications as substitutes for plastic mulch.

Effects of adding different boron compounds to the urea-formaldehyde resin were evaluated relative to the physical, mechanical, and other properties of medium-density fiberboard (MDF). While the chemical addition of boric acid to the urea-formaldehyde resin increased the modulus of rupture and modulus of elasticity values of MDF boards, the physical and chemical additions of other boron compounds decreased those values. While there were no significant decreases in internal bond values, the chemical addition of boric acid and borax decahydrate to urea-formaldehyde resin increased the internal bond values of MDF boards. It was observed that in both types of addition, borax pentahydrate reduced the formaldehyde emission values of MDF boards the most and also reduced the burnt area by up to 30%. When the type of addition of boron compounds to urea-formaldehyde was compared, the addition of boron compounds at the resin formation stage showed better results in the properties of MDF boards than physical addition.

A study was conducted in sandy clay loam soils in a subtropical zone of Bihar to evaluate the effect of frequent application of organic amendments on sulphur fractions. Different organic amendments, including farmyard manure (FYM), vermicompost, azotobacter, phosphate solubilizing bacteria (PSB), panchagawya, and neem cake, were applied through nine treatments that resulted in a significant increase of water-soluble S, available S, heat-soluble S, adsorbed S, and organic S in organic treatment compared to the recommended dose of fertilizer (RDF) and control treatment. The maximum increment was observed in the treatment where the recommended dose of nitrogen was replaced by 75% recommended dose of nitrogen substituted farmyard manure + 25% recommended dose of nitrogen (vermicompost) along with azotobacter + PSB + one foliar spray of panchagawya. The total S content varied widely from 382 to 736 mg kg^-1. Increment in all the forms of sulphur is observed as a result of the application of different organic nutrient sources. All the forms of sulphur share a mutual positive and significant correlation with each other. Regression analysis suggested that the availability of sulphur was dominated by organic sulphur, which alone can explain 97.8% of the variation in availability of available sulphur in soil.