Volume 16 Issue 3

Chinese traditional timber frames are known for their mortise-tenon joints and wooden planks shear walls. To investigate the seismic behavior of the structural system, three full-scale timber frames were subjected to in-plane quasi-static loading. The hysteresis characteristics, lateral load-carrying capacities, lateral stiffnesses, and energy dissipation capacities of the timber frames were investigated. The results showed that the hysteretic loops of all specimens exhibited pinching, and the column and beam components were nearly intact after the test. The traditional wooden frames had large deformability. The installation of the infilled timber shear wall brought great improvements in lateral resistance and energy dissipation to the bare frames. The initial stiffness of the timber frame infilled with timber shear wall was 0.113 kN/mm, which was 56.9% and 11.9% greater than those of the bare frame specimen F1 and specimen F2, respectively. The results from the experimental analyses can serve as a technical basis for the development of seismic design methods and strengthening designs of such structures in practical engineering.

This study examined how nutrients present in the growth environment of microorganisms forming a consortium of bacteria and yeasts, called a symbiotic culture of bacteria and yeast (SCOBY), affect the efficiency of cellulose synthesis and selected properties of the cellulose, such as gloss and color. The results showed that nitrogen-rich ingredients, such as peptone and green tea, increased the efficiency of polymer synthesis and determined the cellulose’s gloss. This research showed that the qualitative characteristics of bacterial cellulose can be easily modified by the appropriate selection of the components of the culture media.

The efficacy of additional water-soluble additives was studied relative to the physical and mechanical properties of particleboards produced from oil palm empty fruit bunch (OPEFB). Polyethylene glycol, acrylamide, and acrylic resin were selected as water-soluble additives for use in the OPEFB particleboard production process. The effects of the three additives at two different concentrations (2% and 4% of dry OPEFB mass) on the particleboard properties were evaluated. Addition of water-soluble additives increased the performance of the OPEFB particleboard. The additive concentration has a significant effect on the properties of the particleboard. With the increase of additive concentration, the internal bonding and modulus of rupture value increased while the thickness swelling and water absorption decreased. Particleboards with an additional 4% of acrylamide or polyethylene glycol achieved the highest modulus of rupture (22 MPa), highest internal bonding strength (1 N/mm2), and lowest thickness swelling (9%). All the particleboards produced with 4% of water-soluble additive achieved the standard requirements of JIS A 5908:2003 for physical and mechanical properties.

The characterization of the curing process allows the determination of the optimal pressing parameters, which is essential for the economical production of wood-based composites. In this study, an automated bonding evaluation system (ABES), dielectric analysis (DEA), and dynamic mechanical analysis (DMA) were used to determine the curing parameters of biobased pine tannin-hexamine adhesive at five temperatures ranging from 75 to 175 °C. This study aimed to compare the three above methods and to find correlations between them. All methods showed the same trend of the curing process, which became faster with increasing temperature. Due to various heating rates among the different methods, the curves representing the degree of cure were shifted to the left for the period in which nearly isothermal conditions were reached. It was determined that these methods could be mutually comparable. The ABES was regarded as the reference method; the DEA was regarded as a method that overestimates the curing process and that describes the beginning of the curing process more precisely; and the DMA method was regarded as a method that underestimates the curing process and that describes the end of the curing process more precisely. Linear trend lines were found between the observed methods.

Catalytic systems were investigated for the ethanolysis of expired food into 5-ethoxymethylfurfural (5-EMF). Fructan-rich expired food (expired probiotics beverage powder, onion powder, garlic powder, and burdock tea), and starchy expired food (expired steamed buns and egg yolk battercake) were tested as starting substrates. Optimization of the reaction conditions included varying the catalyst type, temperature, catalyst loading, and reaction time to maximize 5-EMF yield. Several co-solvents were added to evaluate their impact on the generation of 5-EMF. The selected expired foods produced 5-EMF yields ranging from 0.2 mol% to 68 mol%. The 5-EMF yield from fructan-rich expired food was more noticeably affected by the content of the non-carbohydrate part than that from starchy expired food. The effect of co-solvents on conversion efficiency was closely related to the catalyst type but was not strongly correlated with the feedstock used. This study provides a facile way to produce biofuel chemicals from carbohydrate-rich expired food.

There have been recent attempts to revive the traditional production of handmade paper from the bark of the Coi (Streblus asper Lour.) tree in Thailand. A sheet sample of Coi handmade paper, made from the traditional production, was collected and examined microscopically for the first time. Film-like material and cubic calcium particles were found on the sheet sample surface, which is consistent with the results of the authors’ previous research. Meanwhile, handsheets derived from Coi pulp fiber, freshly made in the laboratory, demonstrated a low air permeance and brightness with high opacity due to the film-like material and cubic calcium particles. With a high felting power of Coi pulp fiber coupled with a possible strengthening role of the film-like material, both the beaten and unbeaten fibers were used to form handsheets with high strength. Some potential aspects of Coi pulp fiber suitable for creating a unique Thai banknote paper have been demonstrated, for which further studies are suggested.

Reducing carbon emissions is the direction various industries will head in the future. Solid wood furniture products that occupy important market shares have high carbon reduction potential. This article briefly describes the carbon footprint of the solid wood furniture production process. In addition, it analyzes the feasible carbon reduction technologies applicable during the design and manufacturing process through the potential emission reduction-oriented approach, ranging from the upstream raw materials to overall power consumption. The primary carbon reduction potential points entail the high efficiency and reuse of primary materials, the reduction of auxiliary materials, and the optimization of solid wood processing based on spraying and dust removal. In this study, the carbon reduction design of solid wood furniture primarily covers the design methods, material selection, structural design, and packaging design. The carbon reduction manufacturing technology was analyzed from a process, equipment, and management aspect. It is hoped that this study can provide a reference for the future strategic design of solid wood furniture companies, which will promote low-carbon development in the wood furniture industry.

Methylxanthine’s fungicidal properties were investigated, with attention to the temperature of treatment. Caffeine and theophylline treatments of beech and spruce woods were applied for three months in the temperature range of -20 to 40 °C, simulating potential weather conditions in the European region and temperatures specific for various wood applications (cellars, wine cellars, room indoor temperatures, interior trusses). Effects of the selected temperatures were considered without the influence of the other possible factors, which have been considered in previous studies (e.g. effects of temperature in combination with other factors such as UV radiation, humidity, and chemical or biological degradation). Then, the specimens were exposed to a mix of molds and fungi for three months under controlled laboratory conditions in order to analyze a possible subsequent biological attack. The results did not show any effect of temperature of the methylxanthine treatment within the studied range on the organismal activity. Caffeine exhibited a better protective potential than theophylline and was more effective for spruce than for beech. The results indicated the suitability of caffeine for protection of spruce and spruce-based materials in interior applications at a stable temperature without significant effects of UV and humidity.

Furniture manufacturers’ response to the demographic challenge of aging nations is an important issue. The number of seniors is rising worldwide. The aging process often results in multiple health implications, including weaker mobility, decrease in muscle mass, and change in anthropometrical dimensions of the human body. Thus, the furniture offered should be adjusted to the needs of an increasing group of senior customers. To identify seniors’ preferences in relation to characteristics of sitting furniture, international surveys with 627 respondents aged 60+ years were conducted in Poland, Germany, Denmark, Finland, Latvia, and Lithuania. The implementation of this data in the design process may result in creation of the market offer meeting seniors’ needs. Design and functionality features were examined to provide guidance for senior-friendly development of furniture for sitting. Among the most important findings is the clear preference of having an armchair with the high backrest reaching above the head, a chair with armrests and an upholstered backrest and seat. Furthermore, respondents paid attention to the durability of furniture, stain resistance of upholstery, and adaptation of the furniture to the user’s dimensions, e.g., having influence on the height and depth of the seat before the purchase.

A visualization method was used in this work for the 3D morphology of internal defects in wooden products using a Philips Brilliance 16 computed tomography (CT). To obtain a high-quality 3D digital model, the original images from the CT scan were segmented to manually color the cross- and vertical sections of the wooden specimen. Through coloring, the reconstructed model showed the accurate 3D morphology of internal defects, such as cracks, wormholes, and decay parts, as well as clear shapes of borer excrement, nails, bark, and wood parts of the specimen. The results suggest that this method provides precise 3D models of different types of defects in the wooden specimen. It can also accurately measure the size and angle of the defects at any position for further observation. This method can be effectively used for non-destructive testing of wooden products and wooden cultural relics and can provide accurate scales of defects and intuitive 3D models for wooden products and wooden cultural relics restoration.