Volume 19 Issue 3

Cellulose films, predominantly consisting of micro-nanocelluloses, are a new type of product with interesting properties for functional packaging applications. However, the potentially scalable production methodology has not yet been elucidated. Poor dewatering and high web shrinkage are issues that need solutions beyond what is available in conventional paper production. This research investigates a cyclic pressing method that shows potential in cellulose film consolidation. Cyclic pressing allows the MNFC films to be dewatered to about 90% solids while yielding a smooth, flat product. The results show no inherent physical limits for mechanical dewatering these high swelling webs, even at very high solids. Cyclic pressing allows controlled restraint during consolidation, which could be adjusted in an industrial setup to produce even films with desirable product characteristics.

Walnut cake has the potential for use in preparing wood adhesives because of its richness in protein and carbohydrate. In this work, walnut cakes were treated with sodium periodate or potassium permanganate and then were directly used as wood adhesives. Their bonding properties, curing performances, thermal properties, and chemical structures were compared. The results showed that: (1) The oxidation by KMnO₄was non-selective. The reaction was very intense, accompanied by the great variability of oxidation degree and degradation degree, enormous viscosity of oxidation products, high coating difficulty, and low content of active aldehyde groups. (2) The oxidation by NaIO₄ was selective; the reaction was mild and easy to control. More active aldehydes could be produced and the treatment was beneficial for constructing a spatial net structure of the adhesive. (3) Compared with oxidation of KMnO₄, the walnut cake adhesive prepared by NaIO₄ oxidation exhibited a more compact structure, a higher crosslinking degree, low curing temperature, and high thermal stability after curing; its bonding performances met the requirements for Class II plywood specified in GB/T 17657(2013).

The composite ZnO@CDs was prepared via the hydrothermal method. Microcrystalline cellulose (MCC) was used as the source of carbon dots (CDs). X-ray diffraction, Fourier transform infrared spectrometry, scanning electron microscopy, and transmission electron microscopy analyses were used to characterize the structure and morphology of ZnO@CDs. The prepared ZnO showed a flake morphology with the exposed plane of (001). The X-ray photoelectron spectroscopy and photoluminescence spectroscopy (PL) characterization showed that CDs can be produced by decomposition of MCC and then attached on the surface of ZnO. The photocatalytic properties of ZnO@CDs were investigated under simulated sunlight irradiation. The hydrogen production reached 1240 µmol·g^-1 in 30 min, which was much higher than the bare ZnO. The mechanism for the enhanced catalytic property of ZnO@CDs was studied. A high hydrogen production rate (2480 µmol·g^-1·h^-1) in the short term would enable ZnO@CDs to work as an emergency power supply by hydrogen production and use for restoring electricity and wireless communication in complicated situations.

This research introduces an innovative methodology for evaluating and predicting soundboard quality in the intricate craftsmanship of sape instruments. Despite the sape’s profound cultural significance, the process of selecting soundboard wood has been inadequately explored, resulting in uncertainties within the crafting community. Addressing this research gap, this study integrates advanced machine learning techniques and devises a specialized Graphical User Interface (GUI) tailored for sape makers. The methodology encompasses a thorough acoustic analysis of three distinct hardwoods—adau, merbau, and tapang—employing machine learning classification through Support Vector Machine with a Gaussian kernel. The study culminates in the development of a user-friendly GUI for soundboard quality assessment. Results underscore the model’s proficiency for achieving an optimized accuracy of 87.8% in classifying sape audio samples. The MATLAB App Designer-based GUI streamlines the evaluation process, offering a practical and accessible tool for craftsmen. This integrated approach, harmonizing traditional craftsmanship with cutting-edge technology, holds the potential to revolutionize sape instrument manufacturing, ensuring the preservation and progressive evolution of this rich cultural heritage.

To meet the functional and emotional needs of users for outdoor leisure chairs, the three-level theory of harmonious design was applied. A product design process was put together based on the Kano model and analytic hierarchy process (AHP). The Kano model obtained demand attributes and influence coefficients, while the AHP obtained total weights. The target products were designed and evaluated based on the three-level theory of harmonious design to improve the user experience and satisfaction of outdoor leisure chairs. The attribute categories of harmonious demand were obtained based on the Kano model, and the harmonious demands were ranked by importance. The design analysis and design practice were conducted with the goal of harmonious design. The AHP was used to analyze the comprehensive weights of the index factors, evaluate the user satisfaction of the three design schemes, and conduct consistency test and feasibility verification of the design schemes. The optimal design scheme was selected based on the total weight mean of three design schemes. The design and analysis method based on the Kano-AHP model can focus on user demand. It can objectively and efficiently analyze design pain spots, and effectively guide the harmonious design practice, which improves user satisfaction and market transformation efficiency of creative products.

This paper proposes a furniture design method combining Kansei engineering (KE) and shape grammar (SG), to explore how the diagonal ridge elements of classical Suzhou-style buildings can be applied to furniture design and to explain how the styling elements match the cultural imagery in furniture products. Suzhou-style armchairs and cultural elements of diagonal ridges were collected, the most suitable armchairs were selected for incorporating such elements, and their shapes were deconstructed along with characteristic interpretations. A factor bank of diagonal ridge elements was constructed, first through Kansei word selection and evaluation experiments, and then through factor analysis which determined the main cultural elements of the design. The shape grammar theory was applied to design and innovate the selected armchair samples, achieving three design solutions. The solutions were then comprehensively evaluated, and the optimal one was used for the final physical product. The results of the study showed that users had clear subjective feelings about the design incorporating diagonal ridge elements, with their Kansei on three aspects: aesthetic style, decorative complexity, and structural balance. The approach used in this work blends furniture products with cultural imagery on diagonal ridges, providing a feasible methodological reference and an empirical case for cultural sustainability through furniture design.

This study was conducted to investigate some characteristics of thermally treated Scots pine (Pinus sylvestris L.) wood specimens such as air-dried density, color change, average surface roughness, and sound absorption capacity. Heat treatment of Scots pine wood was performed at atmospheric pressure at 140, 160, 180, and 200 °C for 2 h. As a result, the air-dried density values of the thermally treated wood decreased as the temperature of the thermal treatment increased. With the increase of thermal treatment temperature, an increase in total color change values was detected on the surfaces of the samples and the color of the samples became darker. The average surface roughness (R_a) value of samples improved due to thermal treatment conditions and the highest value was determined in thermally treated samples at 200 °C as 3.59 μm. At 140 °C the value of maximum sound absorption coefficient was observed to be 0.48 at 2500 Hz and the highest sound transmission loss value, which was 36.7 dB, was measured at 6300 Hz and at 200 °C.

Pretreated carboxymethylated nanofibrillated cellulose (CM-NFC) was tested as a strength enhancer for specialty paper, such as banknotes made from cotton linter mixed pulp (CLMP). The pretreatment agent was cationic poly(acrylamide) (C-PAM). The CM-CMF prototype was supplied by a Korean manufacturer. Laboratory tests and pilot trials were performed to evaluate the strength enhancement of banknotes incorporated with surface-modified CM-NFC and determine the process problems encountered in a pilot paper machine. The CM-NFC was surface modified with 0.1% C-PAM without any agglomerates. The prepared laboratory handsheets had high paper strength, which was attributed to the higher nanofibril content of surface-modified CM-NFC compared with that of unmodified CM-NFC. Pilot trials showed that the incorporation of 3% surface-modified CM-NFC was highly effective in promoting the strength of banknote without low retention and drainability on the wet-end part of the pilot paper machine. Therefore, surface-modified CM-NFC at a controlled dosage could be used as a strength enhancer for specialty paper without incurring serious problems in a paper mill.

Key components of the existing external meshing dorsal spine plunger-type molding machine were modeled in three dimensions, and the fatigue life analysis of the molding machine spindle was carried out by using Ansys software. Due to the nonlinear mechanical behavior of the material ring mold, and pressure roller in the granulation process, there are a lot of contacts and collisions. Using the linear mechanics model is difficult to analyze. To achieve more accurate and realistic results, an Edem-Ansys joint coupled simulation was carried out for the pressure roller and ring mold engagement process. The results showed that the stress concentration point and fatigue weak region of the spindle occurred at the shaft cross-section, where the stress value should be less than 0.75 F. The maximum stresses and strains in the engagement process of the pressure roller and the ring die body occurred at the engagement point. The maximum values of deformation, stress, and strain were 0.039 mm, 412 MPa, and 0.002 mm/mm, respectively, which are all within the reasonable range and meet the design requirements.

The study aim was to optimise the C/N ratio, improve the compost quality, reduce pathogenic bacteria load in the compost, and improve guava yield. Vegetable wastes were mixed with cow dung, grasses, and food wastes in ratios of 4:3:2:1 (w/w) for achieving a C/N ratio of approximately 37. Co-composting is an important strategy because the mixture of bulking agents can help achieve optimal composting conditions. Experimental results were obtained from a pilot-scale rotary drum reactor with forced aeration. In the reactor, the temperature increased during the thermophilic phase (58±2 °C) and decreased after 10 days (54±2 °C). The pH values moderately increased, then decreased, and were near to neutral after maturation. The results indicated that co-composting of bio-wastes at a C/N ratio of 37.6%±1.02% could be effectively decomposed to reduce the residuals to just 13.6%±1.05% after 28 days. The microbial population increased in both mesophilic and thermophilic stages and decreased at the end of the composting, reflecting stability. The stable compost was applied to the growth of guava plant, and the yield was calculated. The organic compost improved plant growth, fruit yield, and enriched phytochemical compounds in the fruit and peels. The phytochemical compounds improved antioxidant activity in the guava fruits.