• Journal of Welding and Joining
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• v.25 no.6
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• pp.4-10
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• 2007

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.154-160
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• 1982

One dimensional unsteady heat conduction was studied on soybean curd as a water-protein-fat food system. This heterogeneous soybean curd could be treated as homogeneous material as for the unsteady heat conduction by 'effectiver' thermal diffusivity. Measurements were made with a apparatus designed and constructed by the author and also made with ice to establish the reliability, the reproducibility and the accuracy of the apparatus. It was found that the effective thermal diffusivity of soybean curd was substantially dependent on the fraction of protein and fat as well as water.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.1
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• pp.59-70
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• 1998

A steady-state molecular diffusion experiment was conducted to evaluate the water vapor proof properties of paper Handsheets prepared from unbleached Itraft pulps(UKP) and old newspapers(ONP) and four different types of polymer-laminated white duplex board were tested under appropriate standard conditions. The diffusivity was determined on the basis of the Fickean first law. Results obtained from this study can be summarized as follows ; 1. The diffusivity data for handsheets showed about $10^{-5}cm^2/min$. whereas polymer-laminated paperboards had remarkably improved water-vapor resistance with about $10^3 to 10^4$ times lower diffusivity : 2. Sheet basis weight, wet-swelling and sizing degree had little influence on the diffusivity of paper; 3 Linear relationship existed between sheet density and diffusivity, and, 4. Highly sfgnificant linear relationship could be observed between diffusivity and Darcy s gas permeability. Results indicate that diffusivity, an intrinsic property of paper, can provide a valuable information for precise evaluation and improved quality control of water-vapor proof properties of paper.

• Journal of Technologic Dentistry
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• v.39 no.4
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• pp.253-259
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• 2017

목적: 이 실험의 목적은 한국 백삼과 캐나다 백삼의 일반 성분 분석, 항산화력 측정 및 치아 우식 유발균에 미치는 항균 효과를 비교 분석하는데 있다. 방법: 한국 백삼과 캐나다 백삼의 일반 성분은 수분정량, 조지방, 조단백질, 그리고 조회분의 분야에서 측정되었다. 두 백삼을 60% 에탄올에 추출시켜 환원당과 DPPH-scavenging assay를 통해 항산화력을 측정했다. 동일 추출물을 이용, 치아 우식균인 streptococcus mutans에 대해 디스크 확산법과 최소저해농도 측정을 실시해 항균력을 측정 및 비교했다. 결과: 실험 결과, 한국 백삼과 캐나다 백삼은 유사한 조지방, 조단백질, 조회분 성분을 갖고 있었으나 수분정량에서 캐나다백삼이 우세했다. 항산화력 실험에서는 캐나다 백삼이 DPPH- scavenging 능력에서 더 높았으나 환원당 실험과 총 페놀 함량에서는 한국 백삼의 수치가 더 높았다. 디스크 확산법을 통한 항균력 실험에서는 한국 백삼이 캐나다 백삼보다 더 넓은 clearing zone을 형성하고 더 낮은 최소저해농도를 달성해 항균력에서 우세했다. 결론: 한국 백삼과 캐나다 백삼은 비슷한 일반성분과 항산화력을 가졌다. 하지만 한국백삼이 치아 우식 유발균인 streptococcus mutans에 대한 항균력에서 더 우세했다.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.551-561
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• 2007

This case study is about the sampling and interpretation of soil pore water in order to understand and to predict the diffusion and behavior of soil pollution. For the measurement of polycyclic aromatic hydrocarbons(PAHs) in two representative hydrocarbon-contaminated sites, the extraction system of the soil pore water was set up with respect to soil depths and the behavior of contaminants was interpreted. The soil solution extraction system consisted of peristaltic pump, and extraction and sampling compartment, and can measure simultaneously the soil water pressure. The concentration of PAHs with respect to extraction pressure and time decreased due to dilution through soil pore water. Particularly, the concentration of PAHs was more reduced under the unsaturated oxic condition than saturated anoxic condition. Therefore, the soil solution extraction with respect to soil water pressure can interpret the extent of equilibrium between porewater and soil surface.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.1
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• pp.12-17
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• 1984

In order to find out the effects of soil conditioner treatment on the water movement in sandy loam and silt loam soils were treated with two different kinds of soil conditioners, hydrophobic Bitumen 0.4% or hydrophillic Uresol 0.6%, and the changes of wetting angle (soil-water contact angle), penetrability and diffusivity were measured. The results were summarized as follows: 1. Uresol 0.6% treatment decreased the wetting angle of sandy loam more than $10^{\circ}$, but there was no big difference in silt loam. 2. Sandy loam soil was changed to almost hydrophobic and the wetting angle of silt loam soil was increased to $84.9^{\circ}$ as compared to $76.0^{\circ}$ of untreated soil by Bitumen 0.4% treatment. 3. By Uresol treatment, penetrability of sandy loam was doubled but there was not difference in silt loam, and it was decreased to half in two soils by Bitumen treatment. 4. A significant positive correlation between penetrability and the cosine of wetting angle was recognized. 5. Soil water diffusivity was greatly changed by soil conditioner treatment, and the big differences were appeared at lower soil moisture content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.643-648
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• 1996

The changes in hydration of brown rice, Chu-chung byeo(Japonica type) were determined during storage at different storage temperatures($4^{\circ}C$, 2$0^{\circ}C$, 3$0^{\circ}C$ and 4$0^{\circ}C$) in a 4-layered laminated film pouch(PET 12${\mu}{\textrm}{m}$/AI-foil 7${\mu}{\textrm}{m}$/o-Nylon 15${\mu}{\textrm}{m}$/L-Mix100${\mu}{\textrm}{m}$). At the beginning of storage, the hydration rate of brown rice increased with higher soaking temperature, and the activation energy of hydration was 10.3kcal/mole. Water diffusion coefficient of brown rice due to storage temperature during storage at 3$0^{\circ}C$ of soaking temperature was decreased by the elapse of storage periods and increment of storage temperature(below 3$0^{\circ}C$). ).

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.256-262
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• 1988

During soaking of 4 varieties of Korean soybeans in water at $4-98^{\circ}C$, an equilibrium state was reached after 3 hr at $60-98^{\circ}C$ but no equilibrium state was observed at $4-40^{\circ}C$ during soaking for 10 hrs. The moisture gain of soybeans held a linear relation with the square root of soaking time regardless of soaking temperatures, which indicated that the basic mechanism of water absorption was diffusion of water. The log time to reach a fixed moisture content showed a linear relation with the soaking temperature during soaking of soybeans at $4-60^{\circ}C$. The z-value decreased in proportions to the increase of hydration. The z-value to reach 50% hydration was the same in all soybeans.

• Applied Biological Chemistry
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• v.31 no.1
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• pp.21-25
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• 1988

The predominant kernel(7mesh) of naked barleys were polished to give 65% yield. The diffusion coefficients and volume increase rates of polished naked burleys at $40^{\circ}C$ were $3{\sim}4$ and 2.2 times greater than those of naked barleys, respectively. The moisture gains of polished naked barleys were linearly related to the volume increases. The hardness of polished naked burleys during soaking was exponentially decreased.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.204-210
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• 1984

Hydration of twelve japonica (j) and nine j x indica rice varieties was analyzed in terms of mathematical rate equation and a tentative classification of milled rice was attempted primarily on the basis of water uptake race of rice grain at room temperature. No two rice varieties had the same water uptake rate or diffusion coefficient. The rice samples could be classified into three groups. Rices which are considered as having good eating quality had lower water uptake rate.