• Fire Science and Engineering
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• v.24 no.6
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• pp.7-12
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• 2010

This paper is aimed the measurement and estimation the thermal interrelation based on leakage current. The leakage models are analyzed by parameters in open and closed (Panel) states and with wood dust and rainwater, charcoal powder in leakage current occurred point. The thermal characteristic of open state that leakage current is inputted in 90 mA is higher in charcoal powder ($105^{\circ}C$) than in wood dust and rainwater ($88.8^{\circ}C$). Charcoal powder that is inputted in 110 mA shows high thermal characteristic ($238.6^{\circ}C$) and the thermal ($238.6^{\circ}C$) is caused by material strain of electrical wire insulation and Panel. The closed state in 90 mA is higher in charcoal powder ($250.6^{\circ}C$) than in wood dust and rainwater ($90.8^{\circ}C$). The open and closed state appear thermal characteristics of two times in charcoal powder than in wood dust and rainwater. The thermal data that are open and close states are used electrical fire investigation and thermal characteristic for Leakage current.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.134-144
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• 2001

This study was conducted to investigate physicochemical and microbiological properties during composting process when pig manure was composted with some bulking agents(Saw dust, Rice hull, Crushed wood). The pig manure consisted of 2.95% total nitrogen, 4.55% $P_2O_5$, 2.07% $K_2O$, 81.2% organic matter and 14.0 C/N, dry base. The inorganic content of bulking agents were similar one another, and C/N ratio was Saw dust 392. Rice hull 91.5, Crushed wood 266. The temperature of Saw dust composting slowly increased at initial stage, whereas one of Rice hull and Crushed wood rapidly increased and stabilized similarly to outdoor temperature after about 2 month. The pH of compost increased during initial 1 month after decreasing, but thereafter decreased rapidly. The C/N ratio rapidly decreased at initial stage, and it slowly decreased after 1 month. Total nitrogen somewhat increased according to composting process. Ammonium-nitrogen increased until 60th day, and thereafter it was rapidly inclined to decrease. The population of aerobic bacteria, Bacillus spp., actinomycetes and fungi increased up to > $10^{10}cfu\;g^{-1}$ fresh weight, > $10^7$, > $10^8$ and > $10^6$, respectively in Rice hull and Crushed wood composting, and more than ones in Saw dust composting, and specially actinomycetes. The persuasive Bacillus spp. isolated from composting process were B. lentimorbus, B. licheniformis, B. pumilus, B. megaterium, etc.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.266-274
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• 2014

To extend the understanding of the pyrolysis mechanism of wood, we have investigated wood dust charcoal and condensate of volatile organic compounds (VOC) obtained during the pyrolysis of red pine (Pinus densiflora Sieb. et Zucc.) at $180{\sim}450^{\circ}C$ using elemental analysis, IR and GC/Mass. The effect of activation process on the charcoal structure also has been studied by comparing elemental analysis and IR data of charcoal carbonated at $600^{\circ}C$ and charcoals activated at $750^{\circ}C$. The results show that pyrolysis of wood has mainly started near at $240^{\circ}C$ and its chemical components did not changed much up to $270^{\circ}C$. However, the element contents and IR spectra drastically changed at $300^{\circ}C$. The fact that IR peaks related to the aromatic ring of lignin are observed in the charcoal pyrolized at $450^{\circ}C$ indicates that a small part of lignin still remains at this temperature. The chemical structure of the activated charcoal seems almost unaffected by the activation time.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.227-239
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• 1993

The author selected 77 dust emissing processes from 71 types of industries which placed in Sasang Industrial Complex in Pusan. The level of total dust was measured as areal concentration and personal exposure concentration by low volume air sampler and personal air sampler, respectively. Collected samples were classified into 5 groups (chemicals and rubber product, metal product, sawmills and wood, foundries and others). Respirable particulate and total dust of areal and personal exposure were analyzed. The results were as follows; 1. All of the respirable dust concentration and total dust of areal and personal concentration were log-normally distributed. 2. Geometric mean of respirable particulate of personal exposure concentration measured $0.55mg/m^3$ in the first group, $0.86mg/m^3$ in the second group, $0.39mg/m^3$ in the third group, $0.81mg/m^3$ in the forth group and $0.52mg/m^3$ in the fifith group. The exceed rates over TLV (thehold limit values) of total dust were 31.3% in the first group, 31.3% in the second group, 70% in the third group, 80% in the forth group and 13.3% in the fifth group. 3. There were singnificant difference between areal and personal exposure concentration and personal exposure concentration was higher than that of area. 4. In the case of high ratio of respirable particulate to total dust, pneumoconiosis incidence was high even though the workshop was opened and emissing dust concentration was low. These findings suggest that it is desirable to measure respirable particulate in environmental assessment of dust emissing workshops.

• Analytical Science and Technology
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• v.21 no.1
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• pp.1-8
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• 2008

This study was conducted to investigate the characteristics of the leaching of metal components from CCA-treated wood during outdoor exposure. CCA-treated wood specimens were placed horizontally or buried vertically into the soil, and then exposed to the natural environment for a year. Wood samples were collected from the side of the horizontal wood specimens using a drill and saw dust samples were collected at the end of the exposure. Soil samples were also obtained around the wood specimens and at different depths of the posts. Wood and soil samples were analyzed for metals using an atomic absorption spectrometer. Monthly metal concentrations varied greatly and more metals were released when wood specimens were exposed vertically than horizontally. Arsenic was released from the wood by 80 % of the intial content. In addition, more leaching was observed from the zone below the ground than above the ground, and soil around the posts was contaminated with metals released from CCA-treated wood.

• 대한예방의학회:학술대회논문집
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• 1995.10a
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• pp.357-358
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• 1995

• Journal of Biosystems Engineering
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• v.37 no.2
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• pp.82-89
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• 2012

Purpose: The simulation model of a pneumatic conveying drying (PCD) for sawdust was developed and verified with the experiments. Method: The thermal behavior and mass transfer of a PCD were modeled and investigated by comparing the experimental results given by a reference (Kamei et al. 1952) to validate the model. Momentum, energy and mass balance, one dimensional first order ordinary differential equations, were coded and solved into Matlab V. 7.1.0 (2009). Results: The simulation results showed that the moisture content reduced from 194% to 40% (dry basis), air temperature decreased from $512^{\circ}C$ to $128^{\circ}C$ with the particle residence time of 0.7 seconds. The statistical indicators, root mean square error and R-squared, were calculated to be 0.079, and 0.998, respectively, between the measured and predicted values of moisture content. The relative error between the measured and predicted values of the final pressured drop, air temperature, and air velocity were only 8.96%, 0.39% and 1.05% respectively. Conclusions: The predicted moisture content, final temperature, and pressure drop values were in good agreement with the experimental results. The developed model can be used for design and estimation of PCD system for drying of wood dust particles.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.2
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• pp.57-69
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• 2022

This study analyzes the fuel conditions and environmental effects of converting heating in rural villages that rely on fossil fuels into wood fuel. In particular, we tried to derive the most important considerations when using wooden chips as fuel in aging agricultural villages where various variables such as weather, facility characteristics, fuel quality, and maintenance capabilities work. Above all, an experiment was conducted by comparing it with oak trees to determine whether Italian poplar, a representative attribute water created to supply fuel wood in Korea, is suitable for heating fuel. Through experiments, 1) Even though the supply of poplar wood chips during 10 hours of operation was 60.74 kg less than that of hardwood chips, the production of hot water was 140 kWh higher. 2) The higher the exhaust gas temperature, the proportional (increase) oxygen concentration and inversely (decrease) PM and CO emissions. 3) Poplar has twice as much ash content as hardwood and three times more fine dust has been detected, but it meets all the standards for wood quality at the Korea Forest Science Institute. 4) Under the condition that there is a difference in water content (7.7%), hardwood cost 1.13 times more wood chips per 1 MWh than poplar, and even if the water content is corrected equally, hardwood cost 1.05 times more per 1 MWh than poplar. 5) In conclusion, it was proved that the fuel possibility, economic possibility, and environmental possibility of poplar wood chips are sufficient.

• Conservation Science in Museum
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• v.4
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• pp.71-78
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• 2003

The wooden striker on the Divine Bell of King Seongdeok was examined to identify the species of the wood and the outdoor wood weathering caused by solar light, moisture, temperature and air. The species of the wooden striker was identified to Zelkova serrata. When observed the striker with naked eyes, the results were surface discoloration (graying), cracking and roughness. In order to examine the morphological changes according to deterioration type, the specimen were separated to three part(I, II,III-spot). The I-spot was discolored to gray and at the same time entirely covered with dust. So the observation was impossible. The II-spot was also discolored but its texture could be observed. On it could observe numerous fungal hypae and dirts like dust flown into the cell lumens. The cell wall has been so weakened by weathering that it lost the physical intensity. This have made microchecks and splits on the cell wall. Although fungal hypae covered the cell, they did not result in wood decay. The III-spot, located just 0.5 mm below the surface, was maintaining the natural red-brown color of the wood. Its cell wall was similar to that of sound wood. These changes are different from wood decay, and limited only to the surface of the striker-less than or equal to 0.5 mm below.

• The Korean Journal of Mycology
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• v.14 no.3
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• pp.189-194
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• 1986

The aim of this study was to investigate physiological chracteristics of Lentinus edodes in Korea. We tried to detect properties of the several wood-degradative enzymes and investigate patterns of the enzyme production. A specific carbon source was used in the enzyme induction media for each enzymes, and the crude extract was used for the enzyme solution. With these enzyme solution, we investigated optimum temperature and pH conditions of their reactions. Moreover we investigated transition patterns of the enzyme production of the several wood-degrad­ative enzmes from Complex and Saw dust media for the purpose of studying the mechanisms of the wood component degradation by this fungus. It was assumed that the order of the wood com­ponent degradation was cellulose, xylan, and then pectic substances, and that the synergistic effects of these substances also influenced the degradation of wood components.