판형 열교환기의 유로 형상을 모사한 유동장을 대상으로 입자영상유속계를 이용 하여 속도를 계측하였으며, 시계열 속도분포를 고찰하였다. 그 결과 삼각형상 그루브 내의 유동형태는 채널흐름으로부터 전달받은 전단응력이 그루브 내부를 순환하는 회전에너 지로 전환되면서 강제와류와 유사한 달걀형의 일그러진 타원형의 주순환류가 존재하며, 레이놀즈수의 증가에 따라 전단혼합층의 상대적 영향이 감소하였다.

We have developed a cylindrical mixing layer model of a stellar jet including cooling effect in order to understand an optical emission mechanism along collimated high velocity stellar jets associated with young stellar objects. The cylindrical results have been calculated to be the same as the 2D ones presented by Canto & Raga(1991) because the entrainment efficiency in our cylindrical model has been obtained to be the same value as the 2D model has given. We have discussed the morphological and physical characteristics of the mixing layers by the cooling effect. As the jet Mach number increases, the initial temperature of the mixing layer goes high because the kinetic energy of the jet partly converts to the thermal energy of the mixing layer. The initial cooling of the mixing layer is very severe, changing its outer boundary radius. A subsequent change becomes adiabatic. The number of the Mach disks in the stellar jet and the total radiative luminosity of the mixing layer, based on our cylindrical calculation, have quite agreed with the observations.

울릉분지 남부 대륙붕 석유탐사 시추공에서 회수된 사암 내에서 산출되는 녹니석-스멕타이트 혼합층 점토광물에 대하여 광물학적 및 화학적 연구를 수행하였다. X-선 회절분석과 화학분석 결과에 의하면 이 점토광물은 녹니석과 스멕타이트가 1:1 비율로 구성된 이팔면체형의 녹니석-스멕타이트 혼합층광물, 즉 토수다이트이다. 이 토수다이트는 Li가 풍부한 토수다이트로서 열수변질대에서 보고되는 토수다이트와 거의 동일하다. 이것은 토수다이트가 산출되는 지역은 열수변질과 관련된 열적 영향을 받았음을 지시한다. 실제로 이 시추공이 있는 지역은 단층과 습곡이 많이 발달되어 있고 구조적으로 변형되어 있다. 이와 같은 점을 고려할 때 하부로부터 열수가 올라와서 사암 내의 토수다이트의 생성에 기여했을 것으로 생각된다.

본 연구는 일라이트-스멕타이트 혼합층광물(I-S)의 구조를 MacEwan 결정자 모델과 기본입자 모델을 통하여 살펴봄으로써, 팽창성(% SXRD), MacEwan 결정자두께( NCSD), 평균기본입자두께( NF ) 간의 관계를 정량적으로 해석하고자 하였다. 두 모델에 대한 비교를 통하여, % SXRD, NCSD, NF 는 서로 독립된 변수들이 아니고 I-S 구조 내에서 특정한 기하학적 관계를 가지고 있음을 알 수 있었다. % SXRD는 단범위적층효과에 의해 NCSD에 영향을 받고, NF 및 스멕타이트 층간개수( NS )와 Ns =( NF-1)/(100%/% SXRD- NF ) 관계가 성립함을 알 수 있었다. 특히, 이 관계로부터 % SXRD와 NF 는 물리적으로 제한된 조건인 1〈 NF 〈100%/ % SXRD를 만족해야 한다는 결과를 도출할 수 있었다. 본 연구는 이러한 물리적 제한조건을 이용하여, % SXRD, NF , Ns , 질서도 등을 종합적으로 해석하는데 유용할 것으로 사료되는 다이어그램을 제시하였으며, 금성산화 산암복합체에서 산출되는 I-S에 대한 XRD 자료를 이용하여, 이를 검증하였다. 또한, 자연상 I-S는 % SXRD가 감소할수록, NF 는 물리적 상한조건인 NF =100%/% SXRD에서 점차 멀어지게 됨을 알 수 있었으며, 이러한 결과는 기본입자가 두꺼워질수록 적층능력이 감소하는 것에서 기인한 것으로 사료된다.다.하는 것에서 기인한 것으로 사료된다.다.

A Jump model was evaluated for the calculation of hourly mixing height and mean potential temperature within the height. The Jump model was modified for estimation of downward heat fluxes by mechanical convections and surface heat fluxes. The surface heat fluxes were estimated from routine weather data such as solar radiation and air temperature. Total of 8 upper-air data observed at 0000UTC and 0600UTC in Osan station during April 23 to 26, 1996 were analyzed, and compared to the model results in detail. The calculated mixing heights and potential temperatures within the height were comparable to the observations, but some differences were showed. The calculated mixing heights were generally higher than observations. And, when variations of wind directions were large, the large difference of potential temperature was occurred. From the results, it was important to note that vertical motions and advections of air masses would affect to the growth of the mixing height.

One-dimensional thermodynamic mixed layer model to simulate variations of meteorological variables within the planetary boundary layer has been developed in this study. This model consists of 2 prognostic equations, which can predict the variations of potential temperature and mixing ratio and several diagnostic equations. Physics within the surface and mixed layers has been considered seperately in the model. For the variations of the model, its result has been analysed and compared with observated data over the Dukyang Bay for one day, July 23, 1992. The simulated height of mixed layer is comparable to the observation and the variations of temperature and mixing ratio in the mixed layer are also reasonably simulated. Those imply that the model responds appropriately with given boundary conditions in spite of its simplified assumptions applied to the model and insufficient boundary and initial conditions.

The layer that is directly influenced by ground surface is called the atmospheric boundary layer in comparison with the free atmosphere of higher layer. In the boundary layer, the changes of wind, temperature and coefficient of turbulent diffusion in altitude are large and have great influences an atmospheric diffusion. The purpose of this paper is to express the structure and characteristics of development of mixed layer by using laboratory experiment and numerical simulation. Laboratory experiment using water tank are performed that closely simulate the process of break up of nocturnal surface inversion above heated surface and its phenomena are analyzed by the use of horizontally averaged temperature which is observed. The result obtained from the laboratory experiment is compared with theoretical ones from k-ε numerical model. The results are summarized as follows. 1) The horizontally averaged temperature was found to vary smoothly with height and the mixed layer developed obviously being affected by the convection. 2) The mean height of mixed layer may be predicted as a function of time, knowing the mean initial temperature gradient. The experimental values are associated well with the theoretical values computed for value of the universal constant C_T=0.16, our C_T value is little smaller than the value found by Townsend and Deardorff et al.