• Journal of the Korean Wood Science and Technology
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• 제30권3호
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• pp.18-25
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• 2002

Research to discuss the fire performance of materials requires tools for measuring their burning characteristics and validated fire growth models to predict fire behavior of the materials under specific tire scenarios using the measured properties as input for the models. In this study, burning characteristics such as time to ignition, weight loss rate, flame spread, heat release rate, total heat evolved, and effective heat of combustion for four types of wood-based materials were evaluated using the cone calorimeter and inclined panel tests. Time to ignition was affected by not only surface condition and specific gravity of the tested materials but also the type and magnitude of heat source. Results of weight loss rate, measured by inclined panel tests, indicated that heat transfer from the contacted flame used as the heat source into the inner part of the specimen was inversely proportional to specific gravity of material. Flame spread was closely related with ignition time at the near part of burning zone. Under constant and severe external heat flux, there was little difference in weight loss rate and total heat evolved between four types of wood-based panels. More applied heat flux caused by longer ignition time induced a higher first peak value of heat release rate. Burning characteristics data measured in this study can be used effectively as input for fire growth models to predict the fire behavior of materials under specific fire scenarios.

• Interaction and multiscale mechanics
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• 제5권1호
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• pp.75-90
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• 2012

This paper investigates the effects of sports ground materials on the transfer characteristics of the landing impact force using a coupled foot-shoe-ground interaction model. The impact force resulting from the collision between the sports shoe and the ground is partially dissipated, but the remaining portion transfers to the human body via the lower extremity. However, since the landing impact force is strongly influenced by the sports ground material we consider four different sports grounds, asphalt, urethane, clay and wood. We use a fully coupled 3-D foot-shoe-ground interaction model and we construct the multi-layered composite ground models. Through the numerical simulation, the landing impact characteristics such as the ground reaction force (GRF), the acceleration transfer and the frequency response characteristics are investigated for four different sports grounds. It was found that the risk of injury, associated with the landing impact, was reduced as the ground material changes from asphalt to wood, from the fact that both the peak vertical acceleration and the central frequency monotonically decrease from asphalt to wood. As well, it was found that most of the impact acceleration and frequency was dissipated at the heel, then not much changed from the ankle to the knee.

• 한국환경보건학회지
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• 제33권5호
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• pp.451-455
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• 2007

This study was performed to evaluate the effects of input ratios of bulking material in aerobic composting of food wastes on variation of colony forming units(CFU) of fungi. Wood chips were used as a bulking material. Volume ratios of food wastes to wood chips in reactor of Control, WC-1 and WC-2 were 10/0, 10/5 and 10/10, respectively. Reactors were operated for 24 days with I hour stirring by 1rpm and 2 hours of the forced aeration rate of $80L/min{\cdot}m^3$ per day. WC-2 reached high temperature range faster than WC-1, and the maximum temperature of WC-2 was higher than that of WC-1. WC-2 reached high pH range faster than WC-1. and the maximum pH of WC-2 was higher than that of WC-1. WC-2 reached high Log(CFU/gram) range faster than WC-I, and the maximum Log(CFU/gram) of WC-2 was higher than that of WC-1. These all mean that the reaction velocity of composting of WC-2 was faster than that of WC-1. The profile of fungi changes in Log(CFU/gram) was similar to that of temperature changes (r=0.8861) not pH changes (r=0.1631).

• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.63-72
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• 2008

As a part of abating formaldehyde emission of urea-formaldehyde (UF) resin adhesive, this study was conducted to investigate chemical structures of UF resin adhesives with different formaldehyde/urea (F/U) mole ratios, using carbon-13 nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. UF resin adhesives were synthesized at four different F/U mole ratios such as 1.6, 1.4, 1.2, and 1.0 for the analysis. The analysis $^{13}C$-NMR spectroscopy showed that UF resin adhesives with higher F/U mole ratios (i.e., 1.6 and 1.4) had two distinctive peaks, indicating the presence of dimethylene ether linkages and methylene glycols, a dissolved form of free formaldehyde. But, these peaks were not detected at the UF resins with lower F/U mole ratios (i.e., 1.2 and 1.0). These chemical structures present at the UF resins with higher F/U mole ratios indicated that UF resin adhesive with higher F/U mole ratio had a greater contribution to the formaldehyde emission than that of lower F/U mole ratio. Uronic species were detected for all UF resins regardless of F/U mole ratios.

• Journal of the Korean Wood Science and Technology
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• 제37권3호
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• pp.274-286
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• 2009

목질바이오매스 원료는 구성성분 특성 및 분포상 생물 화학적 전환에 매우 큰 장애요소를 지니고 있다. 특히 셀룰로우스를 이용하고자 하는 경우의 리그닌 장애는 해결해야 할 중요한 요소로 인식되고 있어 바이오에탄올 생산에서도 당화공정에 앞서 전처리 공정이 필연적이며 최종 에탄올 수율 및 생산비용에도 영향이 커서 다양한 전처리 방법들이 제안되고 있는 상황이다. 본 총설은 문헌연구를 통하여 최근 세계적으로 진행되고 있는 목질바이오매스 대상의 전처리 연구에 대한 동향을 파악하고, 이들 전처리공정의 특징 및 장단점을 분석하여 국내 목질바이오매스 원료 및 생산여건에 적합한 공정 연구 개발에 필요한 기초자료를 마련하고자 하였다. 국내외적으로 활발하게 연구되는 주요 전처리 기술은 각각 공정 및 경제성 면에서 장단점이 있어 원료나 생산여건 환경에 따라 적합한 전처리 공정을 선택해야 할 필요가 있는 것으로 고찰되었다.

• Journal of the Korean Wood Science and Technology
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• 제50권4호
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• pp.237-245
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• 2022

This study examined the structural performance of experimental parallel strand lumber (PSL) from a Larch veneer strand. The prototype of PSL from a Larch veneer strand was manufactured in the experimental laboratory and tested. The bending and dowel bearing strength were determined from the modulus of elasticity (MOE), modulus of rupture (MOR), and dowel bearing strength based on a 5% offset yield load. The test results indicated that the average MOR of PSL was higher than that of 2 × 4 dimension lumber, and the average MOE of PSL was lower than that of 2 × 4 dimension lumber. A linear relationship was observed between the MOR and MOE. The allowable bending stress of PSL was derived as specified in ASTM D2915 and compared with other research. The dowel bearing strength of PSL in parallel to the grain was approximately double that perpendicular to the grain of PSL. A comparison of several theoretical calculations based on each national code for the dowel bearing strength was conducted, and some theoretical equations produced results closer to the experimental results when it was parallel to the grain, but the difference was higher in the case perpendicular to the grain. The test results showed that PSL made with Japanese larch veneer strands appeared to be suitable for a raw material of structural composite lumber (SCL) appeared to be used as a raw material for SCL.

• Journal of the Korean Wood Science and Technology
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• 제42권3호
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• pp.309-317
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• 2014

수확된 목제품(Harvested Wood Products, HWP)이란 제재목, 합판, 파티클보드 또는 목구조재, 건축내장재, 가구, 종이제품 등과 같이 나무를 원료로 사용하여 가공한 제품을 말한다. HWP는 수명을 다하여 폐기될 때까지 산림에서 생장하면서 저장했던 탄소를 장기간 제품 내에 저장하고 있기 때문에 대기 중의 이산화탄소 농도를 안정화시키는 효과를 발휘한다. 이러한 이유로, 탄소계정 시 목제품의 탄소저장효과를 인정해야 한다는 의견들이 지속적으로 제기되어왔다. 2011년 11월 더반에서 열린 17차 기후변화협약 당사국총회(COP)에서는 자국산 목재 만을 대상으로 하는 생산접근법을 HWP의 탄소계정방법으로 결정하였다. 이에 본 연구는 향후 국가 간 논의 및 협상에 대응하고자 국산 HWP 탄소계정에 필요한 인자인 반감기를 결정하기 위하여, 외국의 반감기 결정사례를 조사하고 국산 HWP 반감기 결정을 위해 필요한 요소를 분석하였다.

• Journal of the Korean Wood Science and Technology
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• 제25권2호
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• pp.21-26
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• 1997

Lignin viscous material was prepared from acetosolve lignin by phenolation and heat treatment. The yield of phenolation was about 160% with p-toluene sulfonic acid(2% of acetosolve lignin) as catalyzer. Phenolated lignin has a good spinnability and thermosetting property by $300^{\circ}C$ treatment with vaccum. Acetosolve lignin carbon fiber has $20{\pm}5$ m diameter and $68.2{\pm}10\;kg/mm^2$ tensile strength. The yield of carbon fiber based on acetosolve lignin was 31%.

• 한국주거학회논문집
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• 제16권4호
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• pp.109-120
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• 2005

The purpose of this study is to find out the Consumers' value about Environmentally-Friendly Interior Finishing Material and to provide essential data for the development of realistic environmentally-friendly material also in compliance with the requirement of consumer. The questionnaire inquiry used of Analytic Hierarchy Process was carried out for both designers and common housewives to characterize the main demanding stratums for interior finishing goods in October, 2004. The results were summarized as follows; The interior finishing materials regarded as important in residential space were by the order of Wood Floor for Ondol, Wall Paper, Emulsion Paint; Environmentally-Friendly Wall Paper appeared its value of 1.56 times than Ordinary Wall Paper, in the same case of Emulsion Paint is at 1.63 times, Wood Floor at 2.12 times, respectively. Besides, as the result of correlation and regression analysis, they preferred to environmentally-friendly property by the nearer women, the nearer larger incomes, the nearer highly educated, and the nearer non-experts (housewives).

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.71-80
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• 1996

Handling the manufacured goods is the most cost-consuming task in material handling system in wooden furniture industries. Fully automated warehouse for cartoned goods of a furniture manufacturing company was analized to provide plant engineers and managers with some important informations on the utility and profitability of the automated storage and retrieval system(AS/RS). Process-oriented simulation modeling tech-niques were used to describe the system and to propose some alternatives to promote the efficiency of AS/RS. Simulation report could be inter-preted as follows: 1. Warehouse for the furniture goods must be designed in accordance with reliable material handling program and constructed with suitable equipments depending on the specification of packed products. 2. An excess of palletized products induced the indigestion and the inefficiency of AS/RS of the furniture industry and put this high-costly system into the shade. 3. Overcrowded AS/RS of the furniture factories could regain its material handling function by cutting down the deposit of products into the automated warehouse. For this purpose, reducing the regular output and direct delivering the outside products to the destination should be considered as the definite counterplan. And additional operation of conventional handy warehouse was also expected to improve the efficiency of main AS/RS.