• 한국환경과학회지
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• 제6권1호
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• pp.69-73
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• 1997

Endotoxin from the cell wall of marine V. vujnificus was .extracted using the hot phenol-water method, injected endotoxin into rat, and tested the toxic effect of endotoxin on the blood component In rat blood. The results showed that blood glucose, blood urea nitrogen, white blood cell, and reticulocyte were Increased and red blood cell was the same as the number of control group(normal blood), but platelet was decreased. Above results suggested that endotoxin induced a malfunction of liver and that the Increase of white blood cell was for the removal of foreign toxic substance.

• 한국추진공학회지
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• 제6권4호
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• pp.25-35
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• 2002

본 연구에서는 액체로켓의 엔진조건에 부합하는 재생냉각 시스템을 설계하는 방법을 다루었다. 정상상태에서 로켓 추력실에서의 열전달 과정은 연소가스로부터 벽면으로 대류와 복사가 이루어지고, 다시 연소실 벽을 통해 전도된 후 마지막으로 냉각제로 대류열전달 된다. criterial method와 integral method를 이용하여 열전달량을 구하고, 이를 이용하여 냉각채널을 설계하였으며, 러시아 냉각 시스템 설계 코드의 결과와 비교하였다. 복잡한 설계과정을 정형화된 logic을 구현하여 냉각 시스템 설계를 용이하게 하였으며, 설계변수를 변화시켜 얻어진 계산결과를 통하여 각 인자의 영향을 정성적으로 살펴보았다.

• 대한기계학회논문집
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• 제14권6호
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• pp.1652-1660
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• 1990

본 연구에서는 원관내에서 복사에 관여하는 고온의 가스유동에 의한 복사열전 달과 대류열전달간의 상호작용에 대해 실험과 수치해석을 통하여 고찰하고자 한다. 실험으로는 프로판가스의 화염생성에 의한 속도, 온도 및 벽면에서의 열유속분포를 측 정하고, 수치적으로는 냉염(cold flame) 상태서 측정한 난류요동성분과 연소시의 입구 속도와 온도를 초기조건으로 하여 밀도와 점성계수의 온동에 따른 변화를 고려한 K-.epsilon. 모델과 구조화근사법 및 최근에 개발되어 사용되기 시작한 Weighted Sum of Gray Gas- es모델을 사용하여 속도, 온도 및 열유속 분포를 계산하여 수치해석의 결과와 실험결 과를 비교함으로써 모델의 타당성을 검증하고, 복사에 의한 열전달량과 대류에 의한 열전달량을 분리하여 각 모드가 온도분포 및 열유속분포에 미치는 영향을 고찰하고자 한다.

• 한국식품영양과학회지
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• 제15권2호
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• pp.165-170
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• 1986

고추 과실의 연화와 관련된 세포벽 다당류의 변화를 조사하기 위하여 조세포벽으로부터 화학적인 방법에 의하여 IAP(ionically associated pectin), CBP(covalently bounded pectin), HF(hemicellulosic fraction) 및 CF(cellulosic fraction) 등의 다당류를 분획하여 그 조성변화를 살펴보았다. 고추 과실 세포벽 구성 IAP와 CBP는 $4{\sim}29%$의 hemicellulose와 $0.9{\sim}2.1%$의 cellulose를 함유하였으며, HF는 $8{\sim}13%$의 pectin과 $0.1{\sim}1.1%$의 cellulose를 함유하였다. 또 IAP와 CBP를 구성하는 polyuronide는 IAP쪽이 높았으나, hemicellulose는 CBP쪽이 높았다. CF를 제외한 모든 다당류는 turning stage 이후에 감소하였다. IAP와 CBP의 구성 polyuronide는 IAP에서는 큰 변화를 보이지 않았으나, CBP에서는 증가하였는데, 이것은 CBP와 결합한 HF의 감소에 기인하며, 이 감소의 주된 원인은 구성 galactose의 손실에 의한 것으로 판단되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.261-266
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• 2000

Temperature variation during silicon wafer baking is mainly due to natural convection caused by temperature difference between silicon wafer and upper plate. Several cases are tested and calculated numerically to improve temperature uniformity. The temperature difference and velocity magnitude in the flow cell is reduced for a small gap between the wafer and upper plate because the natural convection force is suppressed in the small space. The uniform temperature distribution can be obtained with controling the incoming flow distribution from the upper plate. An alternative method is the adiabatic wall condition on the upper plate to maintain the temperature uniformity within $0.3^{\circ}C$ on the water plate.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.111-112
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• 2005

To obtain the single crystal thin films, $CuInSe_2$, mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wail epitaxy (HWE) system. The source and substrate temperatures were 620$^{\circ}C$ and 410$^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobilily of $CuInSe_2$ single crystal thin films measured with Hall effect by van der Pauw method are $9.62\times10^{16}$ $cm^{-3}$ and $296cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the CulnSe$_2$ obtained from the absorption spectra was well described by the Varshni's relation E$_g$(T) = 1.1851 eV - ($8.99\times10^{-4}$ ev/K)T$_2$/(T + 153K). After the as-grown $CuInSe_2$ single crystal thin films was annealed in Cu-, Se-, and In-atmospheres the origin of point defects of $CuInSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The nat ive defects of V$_{Cu}$, $V_{Se}$, Cu$_{int}$, and $Se_{int}$ obtained by PL measurements were classified as a donors or accepters type. And we concluded that the heat-treatment in the Cu-atmosphere converted $CuInSe_2$ single crystal thin films to an optical n-type. Also, we confirmed that In in $CuInSe_2$/GaAs did not form the native defects because In in $CuInSe_2$ single crystal thin films existed in the form of stable bonds.

• 한국소음진동공학회논문집
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• 제12권4호
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• pp.280-286
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• 2002

It has been long suspected that the transition region may give rise to local pressure fluctuations and radiated sound that are different from those created by the fully-developed turbulent boundary layer at equivalent Reynolds number. Experimental investigation described in this paper concerns the characteristics of pressure fluctuations at the transition. Flush-mounted microphones and hot wires are used to measure the pressure fluctuations and local flow velocities within the boundary layer in the low noise wind tunnel. From this experiment we could observe the spatial and temporal development process of T-S wave using Wigner-Ville method and find the relations between the characteristic frequency of T-S wave and free stream velocity and the boundary layer thickness based on nondimensional pressure spectra scaled on outer variables.

• 대한기계학회논문집B
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• 제20권4호
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• pp.1449-1457
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• 1996

In this paper, the unsteady two dimensional model for the thermal stratification in the pressurizer surge line of PWR plant has been proposed to numerically investigate the heat transfer and flow characteristics. The dimensionless governing equations are solved by using the Control Volume Formulation and SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm. The temperature profile of fluids and pipe wall with time are shown when the thermal stratification occurs in the horizontal pipe. The numerical result shows that the maximum dimensionless temperature difference is about O.514 between hot and cold section of pipe wall at dimensionless time 1,632.

• 대한기계학회논문집B
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• 제28권9호
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• pp.1093-1100
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• 2004

Numerical analysis of the heat transfer associated with droplet impact on a hot solid surface is performed by solving the equations governing conservation of mass, momentum and energy in the liquid and gas phases. The deformed droplet shape is tracked by a level set method which is modified to achieve volume conservation and to include the effect of contact angle at the wall. The numerical method is validated through the calculations for the cases reported in the literature. Based on the numerical results, the heat transfer rate is found to depend strongly on the droplet spread radius. Decreased advancing/receding contact angles enlarge the splat radius and in turn enhance the wall heat flux. The effect of impact velocity on the droplet spread is reduced as the droplet size decreases. Also, droplet atomization is observed to significantly enhance the heat transfer rate and the effect is pronounced for a smaller size of droplet. An existing model equation to predict the maximum spread radius is improved for application to a micro droplet.

• 공업화학
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• 제10권2호
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• pp.225-230
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• 1999

Li(DPM)을 원료로 hot wall 수평 관형 반응기를 이용하여 질소-산소 및 아르곤-산소의 분위기에서 $Li_2O$ 고체박막을 LPMOCVD법으로 합성하였다. XRD와 ESCA 분석으로부터 질소-산소 분위기에서는 $Li_2CO_3$막이, 아르곤-산소의 분위기에서는 $Li_2O$막이 성장하였음을 알아냈다. 성막된 산화리튬과 리튬카보네이트는 기판의 실리콘 성분과 반응하여 실리케이트를 형성하였다. 마이크로 trench법과 Monte Carlo 시뮬레이션에 의해 기상반응 속도상수 및 표면반응 속도상수가 얻어졌으며 이를 이용한 성막속도 계산치와 실험치를 비교한 결과 실험조건범위 내에서 잘 일치하였다.