• 한국분말재료학회지
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• 제10권2호
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• pp.136-141
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• 2003

In the present study, $TiO_2$ imbedded copper matrix powders have been successfully prepared from the ($CuSO_4+TiO_2+Zn$) composite salt solution. The composite $Cu/TiO_2$ powders were formed by drying the solution at $200{\sim}~400^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting TOC (total organic carbon) amount with TOC analyzer (model 5000A Shimadzu Co). Phase analysis of $Cu/TiO_2$ composite powders was carried out by XRD, DSC and powder size was measured with TEM. The mean particle size of composite powders was about 100 nm and a few zinc and copper oxide phases was included. The reduction ratio of TOC amount was 60% by the composite $Cu/TiO_2$ powders under the UV irradiation for 8 hours.

• Journal of Pharmaceutical Investigation
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• 제14권1호
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• pp.19-30
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• 1984

The pharmaceutical characteristics of solid indoprofen inclusion complex such as dissolution, permeation through a cellophane membrane, model analysis of interfacial tranesfer, absorption behaviors in rat intestine, and the plasma concentration of indoprofen after oral administrations to rabbits were examined in comparison with those indoprofen alone. The inclusion complex obtained by freeze-drying method showed the higher dissolution rate and membrane permeability among the test powders, and increased significantly the amont of indoprofen absorbed in rat intestine and the levels of plasma concentration of indoprofen after oral adminstrations to rabbits. The increase of bioavailability of $indoprofen-{\beta}-cyclodextrin$ complex was considered due to the increased solubility and dissolution rate of solid powder form.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.65-68
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• 2001

This study was conducted to develop a soil moisture meter using capacitance probe. A parallel cylinder type capacitance probe (C-probe) was fabricated The 5 MHz of crystal oscillator was constructed to detect the capacitance change of the C-probe with moist soil. A third order polynomial regression model for volumetric water content having oscillation frequency changes at 5 MHz as independent variables presented the determination coefficient of 0.979 and root mean square error of $0.031\;cm^{3}cm^{3}$ for all soil samples. A prototype soil moisture meter consisting of the sample container, C-probe, oscillator, frequency counter and related signal procession units presented the correlation coefficient of 0.987 and the root mean square error of $0.032\;cm^{3}cm^{3}$ as compared with the oven drying method for unknown soil samples.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.327-332
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• 1998

Drying shrinkage means the reduction of volume of concrete because of the loss of water in concrete. This shirinkage can cause tensile stresses, crack formations at the exposure surfaces in concretes. The purpose of this paper is to apply differential shrinkage model which uses moisture diffusion equation and to calculate more reasonable shrinkage quantity, the stresses of concretes. The result of this papar is that the mean value of differential shrinkage is similar to the existing result but at exposures surface the shrinkage strains are more large. From this result the possiblility of crack formation can take place. Thus a resonable counterplan for tensile stresses in exposure surfaces is necessary.

• Journal of the Korean Wood Science and Technology
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• 제24권3호
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• pp.37-44
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• 1996

포수상태(包水狀態)의 루부라참나무(Quercus rubra) 시험편을 3가지 등온조건(等溫條件)에서 건조한 결과를 비정상상태(非正常狀態)의 확산(擴散)모델로 추정한 결과와 비교하였다. 표면이 충분히 젖은 상태인 건조초기에는 불안정(不安定)한 확산현상(擴散現象)이 관찰되었으나, 함수율(含水率)별 건조속도의 변이를 Fick's의 확산법칙과 비교할 때 유사한 형태를 보였다. 실험에서 얻은 건조조건별 건조곡선은 확산모델의 수치해석(數値解析) 결과와 거의 일치하였으며, 같은 평위함수율(平衛含水率) 조건에서 건조온도의 증가는 목재표면 보다 내부의 함수율 변화에 더 크게 영향하여 결과적으로 낮은 온도에서의 건조조건이 목재 내의 수분경사(水分傾斜)를 급하게 하는 것으로 밝혀졌다. 본 연구를 통해 목재 건조 중의 내부에 발생하는 수분경사를 추정하는데 비정상상태의 확산모델이 모든 함수율 범위에 걸쳐 유용하게 사용될 수 있음이 밝혀졌다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.402-405
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• 1988

With dichromated bleacher and alcohol drying, over effi. of 81% has been achieved for holographic gratings. It is recorded by two plane waves at 632.8 nm in Agfa 8E75 film. Swollen emulsion and rapid dehydration make a strong modulation. The model works well close to the Bragg condition. It is suggested modified parameters of coupled-wave theory which have good agreement with experimental results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 추계 학술대회논문집
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• pp.114-119
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• 2002

A numerical model is employed for design of a spinner device to dry the 5-th generation LCD glass panel. The turbulent flow in a spinner is driven by rotation of a large disk and suction by the exhaust system connected to vacuum chamber, which is simulated by using the FLUENT package. Based on numerical simulation, the required capacity of exhaust system is assessed. The effects of the presence of cover on the flow characteristics are examined. A computational trouble shooting is attempted to resolve the problem of panel rising which occurred in real experiments.

• Geomechanics and Engineering
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• 제21권6호
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• pp.537-549
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• 2020

The presence of cracks changes the water content pattern during seepage through a cracked soil as compared to that of intact soil. In addition, several different crack networks may form in one soil type. These two factors result in a variation of water contents in the soil matrix part of a cracked soil during seepage. This paper presents an investigation of the effect of crack network representation on the water content of the soil matrix part of cracked soil using numerical models. A new method for the numerical generation of crack networks incorporating connections among crack endpoints was developed as part of the investigation. Numerical analysis results indicated that the difference in the point water content was large, whereas the difference in the average water content was relatively small, indicating the uniqueness of the crack network representation on the average water content of the soil matrix part of cracked soil.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.711-711
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• 2012

이 연구에서는 수심적분된 이차원 비정상 수치모형인 KU-RLMS 모형의 잠김/드러남 기법을 개선하고, 기존의 WAD 기법과 새로 도입한 기법의 정확도 평가를 수행하였다. 기존의 WAD 기법은 수학적으로는 다소 불완전하지만 수치적으로는 손쉬운 방법으로써, 각 시간 단계에서 잠긴 격자 또는 드러난 격자를 시험하고, 각 격자의 경계에서 플럭스에 대한 개폐 조건을 적용하는 방법을 사용하였다. 개선된 기법은 WAD 경계에서의 질량보존을 고려하는 방법이다. 두 가지 잠김/드러남 처리 과정의 정확도 비교는 포물형 수조에 대한 해석해와 수치모형의 결과를 비교하는 방법을 사용하였다. 기존에 WAD 기법은 수치해와 해석해의 위상차가 발생하는 것을 확인할 수 있으며, 진폭은 조금씩 감소하는 현상이 나타났지만, 개선된 기법을 사용할 경우 위상차와 진폭감소 현상이 현저히 개선됨을 확인할 수 있었다.

• Current Research on Agriculture and Life Sciences
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• 제14권
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• pp.37-47
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• 1996

The main objectives of this studies are to present the most desirable rice processing complex model system in a given our situations by comparision and analyzing the major factors and, also recommend the future prospect of the rice processing complex in Korea. There are 3 different rice processing complex models in Korea. Those are concrete bin, flat type steel bin and square bin. These systems have a lot of differences and have their own characteristics such as capital requirement, efficiency, storage capacity and quality controls. The major problems of the existing rice processing centers in Korea are high fixed cost and the unbalnced systems. Following is summary to solve this problems: 1. Development of the large scale harvester and high speed continuous dryer. 2. Quality inspective system of bulk grain and large scale temporary storage facilities. 3. Large size readjustment of arable land. 4. Select the convenient location of rice processing center and formulation of well equipment facilities.