Due to the changes in consumer demand and generational transformations, Kyoto's traditional craft industry has suffered substantial revenue losses in recent years. This research aimed to characterize ...Kyoto's traditional craft industry by analyzing the supplier-customer network involving individual firms within the Kyoto region. In the process, we clarify the community structure, key firms, network topological characteristics, bow-tie structure, robustness, the vulnerability of the supplier-customer network as crucial factors for sustainable growth. The community and bow-tie structure analysis became clear that the traditional craft industry continues to occupy an important position in Kyoto's industrial network. Furthermore, we clarify the relationship between modern and traditional craft industries' network characteristics and their relative profitability and productivity. It became evident that the traditional craft industry has a different network structure from the modern consumer games and electric machinery industries. The modern industries have the strongly coupled component, and the attendant firms there create high value-added and play a significant role in driving the entire industry, while more traditional craft industries, such as the Nishijin silk fabrics and Kyoto doll industries, do not have this strongly coupled component. Moreover, the traditional crafts industry does not have a central firm or a dense network for integrating information, which is presumed to be a factor in the decline of the traditional craft industry.
The development of a natural adhesive composed of materials derived from non-fossil resources is a very important issue. In this study, only citric acid and sucrose were used as adhesive materials ...for particleboard. A water solution in which citric acid and sucrose were dissolved was used as an adhesive, and the manufacture of particleboard with a target density of 0.8 g/cm
3
was attempted under a press condition of 200 °C for 10 min. The optimum mixture ratio of citric acid and sucrose and the optimum resin content was 25–75 and 30 wt%, respectively. The modulus of rupture (MOR) and the modulus of elasticity in bending were 20.6 MPa and 4.6 GPa, respectively. The internal bond strength (IB) was 1.6 MPa, indicating that the adhesive had excellent bond strength. The thickness swelling (TS) after water immersion for 24 h at 20 °C was 11.9 %. The board did not decompose even under more severe accelerated treatments. This meant that the adhesion had good water resistance. The MOR, IB and TS of the board were comparable to or higher than the requirement of the 18 type of JIS A 5908 (2003). Consequently, there is a possibility that a mixture of citric acid and sucrose can be used as a natural adhesive for particleboard.
NO
2
sorption ability of cedar (
Cryptomeria japonica
) timbers was evaluated using a new measuring system that was developed in our previous study. Four drying conditions were applied, namely ...natural drying and three kinds of kiln-drying at 45, 60, and 105 °C. Aeration experiments were conducted using discoid specimens which had a thickness in the longitudinal direction of 1.5 mm, and a diameter of 10 mm. The moisture content was conditioned to 0 or 9 ± 1.0% in each drying condition. As a result, the NO
2
sorption ability declined as the drying temperature increased. Based on the analysis of extractives, it was shown that the extractives content had a high correlation with the contribution ratio of extractives in the NO
2
sorption volume of the specimens that were dried below 60 °C. Therefore, it was elucidated that the specimen dried naturally has the greatest NO
2
sorption ability. Furthermore, the result of the gas chromatography–mass spectrometry (GC/MS) indicated that abietadiene influenced the NO
2
sorption ability. Also, the NO
2
sorption volume was high especially at the initial stage, which is higher under the condition with moisture.
This study examined the influence of moisture content (MC) on NO
2
sorption ability of cedar (
Cryptomeria japonica
) wood using the specimens with different MCs. Four MC conditions were applied, ...namely 0%, 8.6%, 12.7% and 16.5%, based on the differences of bonding condition of water molecule in the wood substances. As a result, the NO
2
sorption volume increased drastically due to the presence of water, and as the MC increased, the NO
2
sorption volume increased slightly. The NO generation volume and nitric acid concentration in the specimens were evaluated after an aeration test, and it was strongly indicated that the NO
2
reacted with water in the specimen, and that the NO generation volume increased as the content of multilayer adsorbed water increased. The nitric acid seemed to be formed by the reaction between NO
2
and water, and it was then held in the specimen. Based on the NO
2
sorption volume calculated using the NO generation volume, it was shown that the NO
2
sorption after 12-h aeration was caused mainly by the reaction between NO
2
and water. Furthermore, the presence of both water and extractives contributed to the NO
2
sorption in the initial period, and the presence of water contributed greatly to the NO
2
sorption over the long term.
Wood is a valuable material for interiors, and the psychophysiological relaxation effects of volatile organic compounds (VOCs) from wood chips and essential oils have been reported. However, few ...studies have identified the odors in full-scale wooden environment, and also, differences in gender have not been clarified. In this study, we aimed to confirm the effects of VOCs emitted from interior wood walls in both human male and female participants.
We used Japanese cedar timber and analyzed VOCs in the experimental rooms with and without Japanese cedar timber by gas chromatography-mass spectrometry (GC-MS). The physiological effects were measured using neuroendocrinological and immunological parameters in saliva. A questionnaire was used to evaluate the subjective responses to each odor in the experimental rooms.
The main compound emitted from Japanese cedar timber was δ-cadinene, and the total volume of VOCs in the wood condition (presence of VOCs emitted from Japanese cedar) was 282.4 (μg/m
). Significant differences between genders in salivary parameters were shown that there were decreases of α-amylase in wood condition and increases of cortisol in the control (absence of VOCs) condition in female participants compared to male participants. The results demonstrated that VOCs in the experimental room with Japanese cedar timber tend to suppress the activation of the sympathetic nervous activity and non-VOCs of Japanese cedar in the control room increase cortisol in female participants.
These results suggest that an indoor environment with wood interior materials has the potential to be useful for health management, especially women's health.
A natural adhesive composed of only citric acid and sucrose was recently proposed, and its detailed bonding performance has been researched in some wood-based materials. In this study, the effects of ...board density and press temperature on the physical properties of particleboard were investigated. As physical properties, the bending properties, internal bond strength and thickness swelling of the boards were evaluated. When the density was changed from 0.4 to 1.0 g/cm³under a press temperature of 200 °C and a press time of 10 min, the board with a density of 0.8 g/cm³had the best physical properties. When the board was manufactured at press temperatures ranging from 140 to 240 °C for a press time of 10 min and a target density of 0.8 g/cm³, the board manufactured at 200 °C had the best physical properties. The physical properties of the board with a density of 0.8 g/cm³manufactured at 200 °C met the type 18 requirements of the Japanese industrial standard for particleboard (JIS A 5908). The results obtained from Fourier transform infrared spectra suggested that the ester linkages resulting from the reaction between citric acid and wood and/or sucrose were the main adhesion mechanism and resulted in particleboard with excellent physical properties.
This paper describes the features of binderless particleboard manufactured from sugarcane bagasse, under a high pressing temperature of 200–280 °C. Mechanical properties i.e., modulus of rupture ...(MOR) and elasticity (MOE) in dry and wet conditions, internal bonding strength (IB) and dimensional stability i.e., thickness swelling (TS) of the board were evaluated to investigate the effect of high pressing temperature. Recycled chip binderless particleboards were manufactured under the same conditions for comparison, and particleboards bonded with polymeric methylene diphenyl diisocyanate (PMDI) resin were manufactured as reference material. The target density was 0.8 g/cm
3
for all of the boards. The results showed that the mechanical properties and dimensional stability of both types of binderless boards were improved by increasing the pressing temperature. Bagasse showed better performance than that of recycled chip as a raw material in all evaluations. Bagasse binderless particleboard manufactured at 260 °C had an MOE value of 3.5 GPa, which was equivalent to the PMDI particleboard, and a lower TS value of 3.7 % than that of PMDI particleboard. The MOR retention ratio under the dry and wet conditions was 87.0 %, while the ratio for the PMDI particleboard was only 54.6 %. The obtained results showed the possibility of manufacturing high-durability binderless particleboard, with good dimensional stability and water resistance, which previously were points of weakness for binderless boards. Manufacturing binderless boards under high temperature was effective even when using particles with poor contact area, and it was possible to express acceptable properties to allow the manufacture of particleboards. Further chemical analysis indicated a contribution of a saccharide in the bagasse to the improvement of the board properties.
The kinetics of color changes in keyaki (Zelkova serrata Makino) and sugi (Cryptomeria japonica D. Don) wood during heat treatment were examined. The color of wood specimens treated at 90, 120, 150, ...and 180 °C was measured by an imaging spectrophotometer and expressed using CIELAB color parameters. At any treatment temperature, values for L* and Formula: see text decreased and increased in both wood species, respectively, with increased treatment time. Changes in a* and b* varied depending on wood species and treatment temperature. The color changes were successfully analyzed using the kinetic approach applying time–temperature superposition method. This approach elucidated and accurately predicted color changes during heat treatment.
This paper deals with the kinetics of the color properties of hinoki (
Chamaecyparis obtusa
Endl.) wood. Specimens cut from the wood were heated at 90–180°C as accelerated aging treatment. The ...specimens completely dried and heated in the presence of oxygen allowed us to evaluate the effects of thermal oxidation on wood color change. Color properties measured by a spectrophotometer showed similar behavior irrespective of the treatment temperature with each time scale. Kinetic analysis using the time-temperature superposition principle, which uses the whole data set, was successfully applied to the color changes. The calculated values of the apparent activation energy in terms of
L
*
,
a
*
,
b
*
, and
were 117, 95, 114, and 113 kJ/mol, respectively, which are similar to the values of the literature obtained for other properties such as the physical and mechanical properties of wood.
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