• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.787-798
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• 2017

This is a study on characteristics according to the material of sheet-type mask packs being sold on the market. The absorption capacities of water soluble components such as purified water, 1.3-propanediol, 1.3-butylene glycol, glycerine, and hyaluronic acid are compared with that of various oils including cyclomethicone, dimethicone, phytosqualane, caprylic capryl triglyceride, grape seed oil, and macadamia nut oil. As a result, all of the water soluble components except purified water showed higher moisture absorption capacity as the viscosity increased. And in case of oil, all oil showed higher oil absorption capacity according to the viscosity. During this test, the mask sheets with the type of acetic acid fermented bio-cellulose showed 500~1,000 times or more absorption capacity on water soluble wetting agent or all oils, which is due to the fine mesh structure seen in the 5,000x enlarged photograph at surface structure. This mesh structure was well recognized on the cross section and these structural features enhance the absorption capacity of water and oil. It is also believed that largely contained water-soluble components and oils facilitate the discharge over time. In addition, since each mask sheet shows their characteristics according to their material, it is intended to be a basic research for manufacturing mask packs good for skin.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.594-601
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• 2021

In order to expanding of the use of steel slag, a by-product of steel industry, as a road paving construction material, this present study confirmed the possibility of the rust formation of steel slag aggregate and evaluated the durability performance and the noise reduction characteristics of asphalt concrete mixture. As a result of conducting the rust formation test of aggregate, no rust was observed in both aggregate, so it is judged that the possibility of rust formation in the actual road water environment is very low. As a result of performing the moisture resistance test, all mixtures showed a tensile strength ratio exceeding 85%, satisfied the standard as asphalt mixture. In addition, the sound absorption coefficient of the steel slag aggregate mixture was measured to be higher than that of the general aggregate mixture. Accordingly, it is speculated th at th e steel slag aggregate mixture can more effectively respond to road noise reduction than the general mixture.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.65-78
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• 1990

For the purpose of Improving the sounding boards for the conventional GAYAKUM, I was making approximately 202 specimens of radial board, 371 specimens of tangential board by cutting along the grain and the part of stem and 31 specimens of the disjointed traditional GAYAKUM made in Paulownia coreana. And it was conducted to measure specific gravity, dynamic Young's modulus, internal friction, resonant frequency, velosity of sound and width of annual ring by the method of the frexural vibration in a free-free bar in the audio frequency range. And it confirmed the juvenile wood by measuring wood fiber length of specimens. It was also conducted to investigate dynamic properties and moisture absorption by various heat-treatment and to test dynamic Young's modulus and internal friction for the disjointed conventional GAYAKUM. The results obtained were summarized as follow: 1. The Juvenile wood is located within about 7 annual rings from the pith in Paulownia coreana. 2. As increased with the specific gravity, the dynamic Young's modulus had more and more increased, but the internal friction had slightly decreased. 3. I think that radial board would be good for sounding board wood. because radial board is higher than tangential board in dynamic Young's mudulus and internal friction is lower than tangential board. 4. The value of mean dynamic Young's modulus on the conventional GAYAKUM, radial board and tangential board of 604 samples is $0.4283\pm0.037(\times10^{11}dyne/cm^2)$, $0.4316\pm(\times10^{11}dyne/cm^2)$ and $0.4234\pm0.112(\times10^{11}dyne/cm^2)$ respectively. The value of the radial board showed little higher than that of conventional GAYAKUM, but It had a similar tendency between conventional GAYAKUM and tangential board. 5. The annual ring width by four aspect is more narrow in north and west than that of others. 6. The values of specific gravity and dynamic Young's modulus in the mature wood showed higher than those of juvenile wood. 7. As the grain angle in the butt wood more increased to bark from pith, the dynamic Young's modulus were low. Then it was not good for sounding board. 8. It appeared that the heat-treatment for sounding board wood had a more effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature. 9. As increased with the temperature, the rate of moisture absorption of heat-treatment wood had decreased. In conclusion, I thought that the sounding board wood for GAYAKUM would had the most effect to do the treatment of hotiron on surface after heat-treatment during 24 hours in $60^{\circ}C$ temperature using the radial board of mature wood.

• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.70-75
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• 1998

In this paper, the relationships between volumetric mixing ratio of rubber chip and physical and mechanical properties of wood/rubber composite panel was examined in order to investigate the mixture characteristics of wood and rubber chip. Because of the specific gravity of rubber differed from wood chip, physical properties of wood/rubber composite panel was shown very different values by mixing rate of chip element. Specific gravity in air-dry of composite panel was increased rapidly as volumetric percent of rubber chip was increased. Moisture content of composite panel was decreased as volumetric percent of rubber chip element was increased. This results was considered that wood weight is light and porosity material for moisture absorption. Compressive strength and modulus of rupture in bending test were decreased as volumetric percent of rubber chip increased. By mixing ratio control of chip elements, various wood/rubber composite panel can be applicable to every interior materials such as subfloor, playground, and exterior materials such as road blocks for recreational facilities in garden and forest and city parks.

• 보존과학연구
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• s.7
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• pp.56-86
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• 1986

The aim of this study is to scientifical conservation for the Sin An Ship. The test object is Pinus massoniana and Cunninghamia lanceolata of Sin An Ship's timber .Comtrast object is water soaked fresh wood of Pinus densiflora and Cryptomeria japonica The results were as follows.1. M. C is 280.9% in high degraded Planking board,237.5% in low degraded Planking board,158.6% in fresh wood of Pinus densiflora,222.6% in Bulkhead167.3% in fresh wood of Cryptomeria japonica2. Absorption rate of P.E.G is good at heating condition ($55∼60^{\circ}C$), especially in highdegraded wood.3. The dimensional change of wood during air drying is somewhat shrinked That's 7.22% in low degraded Planking board9.8% in high degraded Planking board and 4.11% in water soaked Pinus densiflora.4. The dimensional change of wood during P.E.G treatment is mostly swollen of wery small quantity.5. Salinity in desalinization tank showed below 50 p.p.m. It's indicate the end of desalinization treatment.6. Filtration with filter paper was possible up to 40% concentration only. Key words :M.c ; Moisture Content, Absorption rate, Dimension change, Salinity, Filtration.

• Journal of Biosystems Engineering
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• v.37 no.1
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• pp.51-57
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• 2012

Purpose: The compression strength of corrugated fiberboard containers used to package agricultural products rapidly decreases owing to various environmental factors encountered during the distribution of unitized products. The main factors affecting compression strength are moisture absorption, long-term top load, and fatigue caused by shock and vibration during transport. This study characterized the durability of corrugated fiberboard containers for packaging fruits and vegetables under simulated transportation conditions. Methods: Compression tests were done after corrugated fiberboard containers containing fruit were vibrated by an electro-dynamic vibration test system using the power spectral density of routes typically traveled to transport fruits and vegetables in South Korea. Results: To predict loss of compression strength owing to vibration fatigue, a multiple nonlinear regression equation ($r^2=0.9217$, $RMSE=0.6347$) was developed using three independent variables of initial container compression strength, namely top stacked weight, loading weight, and vibration time. To test the applicability of our model, we compared our experimental results with those obtained during a road test in which peaches were transported in corrugated containers. Conclusions: The comparison revealed a highly significant ($p{\leq}0.05$) relationship between the experimental and road-test results.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.89-94
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• 2005

The compression strength of corrugated fiberboard container for packaging the agricultural products rapidly decreases because of various environmental conditions during distribution of unitized products. Among various environmental conditions, the main factors affecting the compression strength of corrugated fiberboard are absorption of moisture, long-term accumulative load, and fatigue caused by shock and vibration. An estimated rate of damage for fruit during distribution is about from 30 to 40 percent owing to the shock and vibration. This study was carried out to characterize the durability of corrugated fiberboard container for packaging the fruit and vegetables under simulated transportation environment. The vibration test system was constructed to simulate the land transportation using truck. After the package with corrugated fiberboard container was vibrated by vibration test system at various experimental conditions, the compression test for the package was performed. The compression strength of corrugated fiberboard container decreased with loading weight and vibrating time. The multiple nonlinear regression equation for predicting the decreasing rate of compression strength of corrugated fiberboard containers were developed using four independent variables such as input acceleration level, input frequency, loading weight and vibrating time. The influence of loading weight on the decreasing rate of corrugated fiberboard container was larger than other variables.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.23 no.3
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• pp.75-81
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• 1997

It has been used that fluorinated compounds could be applied to cosmetic products. It is that fluorinated conpounds are hydrophobicity and lipophobicity. These fluorinated compounds are reported to form a highly protective and effective film against most aggressive chemical and physical agents. PerfluropolymethyoisopropylEther has homophobicity and are colorless, odorless, tasteless and non-greasy. In this we made a success to formulate the new type of hand care cream using PFPE. PFPE are suitable thickness and chemical inertness to skin. The reason that we select PFPE for this investigation. We developed the new type hand care cream by adsorption and dispersion of PFPE. There are very stable dispersion and highly moisture diffusion control. And these characteristics were verified by actual consumer test.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1393-1395
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• 2004

Arresters are the best protective device on electrical power systems against transient overvoltages generated by lightning and/or switching operation. Nonetheless, arresters will be deteriorated due to absorption of moisture in the environments of its use, repetition in the protective operation to overvoltages, and some defects at manufacturing. It is therefore important to estimate the electrical characteristic changes of ZnO blocks. In this paper, an accelerated deterioration test by a standard lightning impulse current was carried out to extract parameters needed for diagnosing arrester deterioration, and leakage current components were measured. Total energy applied to the ZnO blocks at each time is 1,050[J] in 8/20[${\mu}s$] impulse current. From the experimental results, we proposed electrical parameters and leakage current level to diagnose arrester soundness.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.3
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• pp.334-339
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• 2005

This study was conducted to test the white bread dough with substitution of 1, 2, 3, 4 and $5\%$ kimchi powder on farinograph, extensograph, amylograph, and pH to find the dough development time, stability, extensibility, resistance to extension, temperature at gelatinization, and temperature at maximum viscosity. Dough with kimchi powder showed less moisture absorption than control. Upon increasing amount of kimchi powder, pH was decreased and dough development time was increased Extensibility of dough showed negative correlation with amount of kimchi powder added Gelatinization temperature increased but maximum viscosity temperature decreased as the amount of kimchi powder increased Overall, the samples with substitution of kimchi powder showed better extensibility than the control sample at the first fermentation.