• Journal of the Korean Society of Safety
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• v.31 no.4
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• pp.55-63
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• 2016

A dust explosion is a phenomenon of strong blast wave propagation involving destruction which results from dust pyrolysis and rapid oxidation in a confined space. There has been some research done to find individual explosion characteristics and common physical laws for various dust types. However, there has been insufficient number of studies related to the heat of combustion of materials and the oxygen consumption energy about materials in respect of dust explosion characteristics. The present study focuses on the relationship between dust explosion characteristics of wood dust samples and oxygen consumption energy. Since it is difficult to estimate the weight of suspended dust participating in explosions in dust explosion and mixtures are in fuel-rich conditions concentrations with equivalent ratios exceeding 1, methods for estimating explosion overpressure by applying oxygen consumption energy based on unit volume air at standard atmospheric pressure and temperature are proposed. In this study an oxygen consumption energy model for dust explosion is developed, and by applying this model to TNT equivalent model, initial explosion efficiency was calculated by comparing the results of standardized dust explosion experiments.

• The Korean Journal of Mycology
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• v.3 no.2
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• pp.25-29
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• 1975

Twelve strains of wood decaying Basidiomycetes were tested for ability to decomposelignin in saw dust of Pine, Quelcus, Rawan and Zelkowa, wood and to transform inorganic nitrogen in the medium into organic crude protein. In this test, one strain of Pleurotus ostreatus showed to be 49% of its ability of lignin decomposition. The increasing rate of the crude protein went up to 26%. It is considered, therefore, saw dust can he a useful animal food by microbial treatment.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.89-92
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• 1998

Tannins are complex polyphenolic substances present in plants. They may be classified as either hydrolysable or condensed tannins, and extracts of the latter type have displayed carcinogenic properties in animal studies (Hausen, 1981). The International Agency for Research on Cancer has determined that exposure to airborne wood dust, especially hardwood dust during furniture manufacture, is a cause of sino-nasal cancer, notably nasal adenocarcinoma. (omitted)

• Journal of agriculture & life science
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• v.45 no.6
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• pp.41-46
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• 2011

In this study, in addition to the green tea-wood fiber hybrid composite boards of previous researches, to make effective use of saw dust of domestic cypress tree with functionalities and application as interior materials, eco-friendly hybrid composite boards were manufactured from wood fiber, green tea and saw dust of cypress tree. We investigated the effect of the component ratio of saw dust and green tea on static bending strength performances. Static bending MOE (modulus of elasticity) was within 0.956~1.18GPa, and showed the highest value in wood fiber : green tea : saw dust = 50 : 40 : 10 of the component ratio, and had the lowest value in 50 : 30 : 20 of component ratio. These values were 2.0~3.1times lower than those of green tea-wood fiber hybrid composite boards reported in the previous researches. The bending MOR (modulus of rupture) showed 8.99~11.5MPa, the change of the bending MOR with component ratio of the factors was the same as that of bending MOE. These values had 1.9~3.5 times lower value than those of green tea-wood fiber hybrid composite boards, and showed the slightly lower values than the MOR of particle boards (PB) and medium density fiberboards (MDF) prescribed in Korean Industrial Standard. Therefore, it is considered that these hybrid composite boards need to improve strength performances by component ratio change, hybrid composite with other materials and adhesive change etc. in order to industrialize the hybrid composite boards.

• Journal of the Korean Society of Combustion
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• v.4 no.2
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• pp.11-22
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• 1999

Combustion characteristics of the wood chips(balsa chips) were experimentally investigated with respect to the thermal recycle system of the urban waste. The urban waste contains plastics, vegetable and wood materials. Wood was chosen as an example of the one of the component of urban dust. A small wood chip was burned in a electric furnace by the micro-electric balance. The mass reduction rate was normalized by the initial mass of test piece and the time of volatile combustion end. When the mass of the wood chips(balsa chips) was larger than 0.5g, the combustion similarity was found on the normalized mass reduction rate.

• Journal of Conservation Science
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• v.35 no.3
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• pp.227-235
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• 2019

In Korea, various methods are applied to prevent wooden structures from being damaged by termites. However, since there is no way to quickly bring toxic substances in contact with the termites inside the timber, it leads to the damage of wooden cultural property due to the prolonged period of controlling the termites. Accordingly, an indoor evaluation criteria study was conducted for the introduction of powder-type termiticides in Korea, which produced rapid control effects by drilling wood and directly contacting and transferring toxic substances inside the timber. First, contact toxicity and transfer ability of termite dusts were evaluated to establish the criteria for evaluation of effectiveness against Reticulitermes speratus. The contact toxicity confirmed 100% mortality of fipronil, deltamethrin and cyfluthrin termite dusts within 24 h of contact; however, differences occurred in the active ingredient transfer time to the sublethal. In addition, in the case of transfer ability evaluation, the rate of mortality gradually decreased under 1:9 and 1:25 ratio conditions; however, the difference in the reduction rate was identified depending on the type of termite dust. the results of the evaluation of compressive strength of the wood showed that the difference in the measured values between the control group and the conditions of perforation 1 to 3 times, which does not significantly affect the compressive strength of wood. In this study, the criteria of termite dust selection and evaluation method of dust-type termiticides were presented and the applicability of the method was identified.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.9-17
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• 2012

In this study, in addition to the green tea - wood fiber hybrid composite boards of previous researches, to make effective use of saw dust of domestic cypress tree with functionalities and application as interior materials, eco-friendly hybrid composite boards were manufactured from wood fiber, green tea and saw dust of cypress tree. We investigated the effect of the component ratio of saw dust and green tea on dynamic MOE (modulus of elasticity). Dynamic MOE was within 1.41~1.65 GPa, and showed the highest value in wood fiber : green tea : saw dust = 50 : 40 : 10 of the component ratio, and had the lowest value in 50 : 30 : 20 of component ratio. These values were 1.4~1.6 times higher than static bending MOE of wood fiber - saw dust - green tea hybrid composite boards, and were 2.0~2.9 times lower than those of green tea - wood fiber hybrid composite boards reported in the previous researches. From the results of correlation regression analyses between dynamic MOE and static strength performances, a very high correlation coefficients were obtained, therefore it was found that static bending strength performances can be estimated with a high reliability from dynamic MOE.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.135-142
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• 2006

The package loading process of tile lumbering industry is an operation that after a pair of workers binds three or six lumber into a unit and cut the both ends of the lumber, carry and pack and load the weight cargo of 30-50kg. The package loading process causes lots of noise and wood dust when the lumber are cut and brings about the main cause of the musculoskeletal disorder when workers carry the heavy goods. Therefore, we developed the monolithic package loading equipment cutting both ends that is enable to improve the working method and environments of the existing package loading process. The noise and wood dust were reduced by developing the device and the main cause of shirking duties on working place was solved by preventing the musculoskeletal disorder and improving the working environments as excluding the work of carrying heavy goods.

• Proceedings of the Korean Society of Rheology Conference
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• 2001.09a
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• pp.156.4-156
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• 2001

(No abstract, see full-text)

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.67-76
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• 1996

This study was performed to estimate total dust concentrations and particle size distribution of wood dust in the furniture and sawmill industries. To compare total wood dust concentrations, two samplers recommended by the American Conference of Governmental Industrial Hygienists and by the National Institute for Occupational Safety and Health were used. Concentration data were analyzed by paired-t tests using the SAS program and two parameters of the particle size distributions were determined by histogram. The results were as follows: 1. Particle size distributions showed a unimodal pattern in cutting and a bimodal in sanding operations. Mass median aerodynamic diameters(MMAD) were $17.35{\mu}m$ in cutting, and $1.39{\mu}m$ for small mode and $18.89{\mu}m$ for large mode in sanding operations. The proportions of particle size larger than $9.8{\mu}m$ estimated by the impactor were 61.16 % in cutting and 62.33 % in sanding operations, respectively. 2. The average personal total dust concentrations measured by IPM sampler were $17.12mg/m^3$ (GSD=1.45) from indoor samples, $2.97mg/m^3$(GSD=1.90) from outdoor samples in cutting, and $8.01mg/m^3$(GSD=1.58) from sanding operation. And those of by 37 mm closed-face cassette were $9.12mg/m^3$(GSD=1.46), $1.06mg/m^3$(GSD=1.99) from cutting, and $3.32mg/m^3$(GSD=2.16) from sanding operations. 3. The average area total dust concentrations measured by IPM sampler were $1.88mg/m^3$(GSD=2.04) from indoor cutting, $4.76mg/m^3$(GSD=2.83) from indoor sanding operations. And those of by 37mm closed-face cassette were $0.49mg/m^3$(GSD=2.34) from cutting, and $1.32mg/m^3$(GSD=3.03) from sanding operations. 4. The ratio of personal total dust concentrations measured by 37 mm closed-face cassette to those by IPM sampler were 35.7 %, 53.3 % from cutting, and 41.4 % from sanding operations. 5. The ratio of area total dust concentrations measured by 37 mm closed-face cassette to those by IPM sampler were 26.1 % from cutting, and 27.7 % from sanding operations. 6. A statistically significant difference of total dust concentrations between the 37 mm closed-face cassette and the IPM sampler was found.