The purpose of this paper is to investigate the relationship between static pressure recovery and velocity distributions in case of swirling flow into a conical diffuser. In this research, velocity distribution is measured by a multi-hole yaw-meter. The following conclusions can be drawn from the experiments. (1) The static pressure recovery depends strongly on the strength of a swirl. (2) A high pressure recovery coefficient is achieved by inserting a solid core into the diffuser center.

초 록 덕유산 지역의 개미의 분포와 개미상을 밝히기 위하여 덕유산 지역을 5개 코스로 나누어 1986년, 1989년, 1991년의 3개년간 16차례에 걸쳐 476 colony를 채집하여 4아과 22속 44종의 분포를 확인하였다. 아과별 종조성은 두마디개미아과가 12속 21종으로 가장 많고 불개미아과가 6속 20종, 침개미아과가 3속 4종, 시베리아개미아과가 1속 1종 이었다. 수직분포의 경향은 고도 500 m에서 전체종의 93%인 41종의 집중 분포하고 있었으며 종별수직분포의 상한계선은 고도 700 m에서 일본침개미와 장구개미를 포함한 5종, 고도 1,000 m에서는 침개미, 호리가슴개미, 나도누은털개미, 스미드개미를 포함하여 10종이 분포하고 있었다.

The wind pressure distributions were analyzed to provide fundamental criteria for the structural design on e single-span arched house according to the wind directions through the wind tunnel experiment. In order to investigate the wind force distributions, the variation of the wind force coefficients, the mean wind force coefficients, the drag force coefficients and the lift force coefficients were estimated by using the experimental data. The results obtained are as follows: 1. When the wind direction was normal to the wall, the maximum positive wind pressure along the height of the wall occurred approximately at two-thirds of the wall height because of the effects of boundary layer flow. 2. When the wind direction was 30˚ to the wall, the maximum positive wind force occurred at the windward edge of the wall. When the wind direction was parallel to the wall, the maximum negative wind force occurred at the windward edge of the wall. 3. The maximum negative wind force along the width of the roof appeared around the width ratio, 0.4, and that along the length of the roof appeared around the length ratio, 0.5. 4. According to the results of the mean wind force coefficients analysis, the maximum negative wind force occurred on the roof at the wind direction of 30˚. 5. The wind forces at the wind direction of 30˚ instead of 0˚ are recommended in the structural design of supports for a house. 6. To prevent partial damage of a house structure by wind forces, the local wind forces should be considered to the structural design of a house.

The Cretaceous granitoids related to base metal mineralization in the studied area consist of hornblende - biotite granite, leucocratic granite and micrographic granite. The major - and trace element data from granitoids, when plotted on the Hacker diagram, average contents of Al₂O₃, CaO, Mg0 and Fe₂O₃ decrease while SiO₂ increases in granitoids from Dolsan toward Namhae and Kwangyang areas. Average content of Rb is higher in Kwangyang area while Ba and Sr decrease in granitoids from Dolsan toward Namhae and Kwangyang, and as shown in triangular diagram of RbBa-Sr, which indicates gradual differentiation of granitic magma from Dolsan toward Namhae and Kwangyang. And, studies of major element variation, calc-alkaline index(61.5) and AFM diagram of granitoids indicates that granitoids have been crystallized from a calc-alkaline magma generated by partial melting of the subducted Pacific Oceanic Crust(or Kula plate) at the compressional plate margin, that is, the volcanic arc. Na₂O/K₂O ratio and magnetic susceptibility of granitoids indicate that they belong to I-type and magnetite series. As shown in atoms against pressure diagram, variation to the number of cations Al^(4+) Al^(6+), (Al+Fe^(3+)^(6+), Si, (Mg+Fe^(2+)), and A-site (Na+K) in amphiboles are shown as functions of estimated crystallization pressure, which the amphibole in granitoids crystallized in the pressure range of 1.8 - 3.0 kbar. According to the two-feldspar geothermometry on granitoids of Kwangyang, Dolsan and Namhae areas, the temperature of cessation of exsolution in perthitic alkali feldspars are 476 - 607℃, 489 - 640℃ and 465 - 629℃, respectively, at assumed pressure of 3 kbar, which may be the result of rapid crystallization in the shallow crustal level(5 - 7.5 ㎞).

The granitic rocks in the southern part of the Kyeongsang basin, Korea, are divided into seven masses based on the petrographical features. They are generally characterized by shallow-depth intrusions. The chemical compositions of amphibole and biotite from the granitic rocks show systematic variations in Fe/(Fe+Mg) ratios as well as Mn and F contents. Hornblende geobarometer indicates low pressure condition (less than 2.3 kbar) at the time of final crystallization of hornblende crystals. The composition of biotite indicates that oxygen fugacity has been almost buffered during crystallization regardless of rock types. The oxygen fugacity is presumably close to the value of Ni-NiO buffer. From the Fe-Ti oxide geothermometry, it seems likely that most of the Fe-Ti oxides have been re-equilibrated during cooling and have suffered oxidation under subsolidus condition.

수평자장을 건 Czochralski(HMCZ) 방법으로 자장강도(B)와 도가니 회전속도(C)가 실리콘 단결정의 산소편석에 미치는 영향에 대하여 연구하였다. B=2, 3, 4kG와 C=4-15rpm에서<100> 방향으로 성장시킨 57mm 직경의 단결정들 내의 산소분포는 대체로 축을 따라서 불균일하였고 톱니모양을 나타내었다. 종래의 CZ 방법과 비교할 때, 이러한 산소분포의 불균일성은 위 강도의 수평자장이 결정성장계면으로의 산소전달에 불안정한 요소로 작용했음을 나타낸다고 볼 수 있다. 반면에 C의 증가는 산소분포의 불균일성의 약화와 산소농도의 전반적인 증가를 유도하였다. 이 결과를 토대로 B=2kG에서 27-36ppma인 산소분포를 가진 단결정이 프로그램된 C에 의해서 얻어졌다. 소자제조공정을 모의한 열처리 과정에서 HMCZ 실리콘의 산소석출은 종래의 CZ 실리콘의 산소석출에 비해서 상대적으로 불균일하였고, as-grown 상태에서의 고르지 못한 HMCZ 실리콘의 산소분포가 주요 원인임이 밝혀졌다.

The magnetogram inversion technique (MIT) has been demonstrated as a powerful $quot;remote sensing tool$quot; in estimating ionospheric quantities, such as ionospheric current, field-aligned current, electric potential and Joule heating rate etc. Furthermore it is now possible to infer instantaneous patterns of such global distributions with a high time resolution (say, 5 min) through the numerical method. However, the electric potential distribution estimated from the MIT is very sensitive to the choice of ionospheric conductivity models. It is a serious drawback of the method, since the electric potential over the polar region is a very important quantity reflecting the efficiency of the solar wind-magnetosphere coupling. Thus a realistic conductivity distribution over the entire polar ionosphere is acute. In this paper, we introduce a general concept of ionospheric electric conductivity along with several methods of estimating it.

This paper reports on the investigation of the distributions of sediments and heavy metals in Sooyoung River and its mouth, carried out during the period from July 1990 and August 1991. Since the samples were saline, water analysis was performed by the method of alkaline KMnO₄ and sediment analysis by acidic KMnO₄. Mercury was digested with both nitric and sulfuric acids, and then determined by dithizone CCl4 method. Cadmium, Zinc, Copper, Lead and Chronium were determined by atomic absorption spectroscopy after aliquots of samples were digested with nitric acid and hydrogen peroxide. Mineral components of sediments were identified by XRD and microscopic analysis. The result are as follows : 1. The ranges of COD of water and sediments were 10.6-54.6ppm and 63-26000ppm respectively. 2. The ranges of concentrations of Cadmium, Lead, Copper and Zinc for water were 0.002 -0.024ppm, 0. 013-0.060ppm, 0.013-0.736ppm, 0.003-0.012ppm, respectively. 3. The ranges of concentration of Mercury, Cadmium, Lead, Copper, Zinc and Chromium for sediments were N.D - 0.09ppm, 0 .1-2.07ppm, 0.32-5 2.35 ppm, 1.04 - 20.67 ppm, 7.1-52.50 ppm and 0.23-5.22 ppm, respectively. 4. The mineral components of the sediments were mainly quartz and feldspar.

혼파된 영년채초지에서의 예취빈도와 질소시비가 뿌리의 수량과 심층분포에 미치는 영향에 대하여 연구된 결과는 다음과 같다. 1. 조사된 식생구조에서의 뿌리의 분포는 모든 처리구에서 상층 20cm까지에 그 대부분이 존재하였다. 2. 뿌리의 양은 우점종에 관계없이 모두 높았지만 Arrhenatherum elatius 우점초지에서 가장 낮았고 Alopecurns pratensis우점초지에서 가장 높았다. 3.뿌리의 양은 예취빈도간에는 그 차이가 없었으나 적당한

관광개발에 따른 심한 환경변화가 예상되는 지리산 국립 공원의 어족자원을 보호하기 위한 기초자료를 얻고자 이 지역의 어류분포상을 조사하였다. 국립공원내 하천에서 확인된 어종은 잉어과, 퉁가리과 및 농어과가 포함된 3과에 속하는 4종이었다. 우점종은 갈겨니였으나 이미 보고된 자료보다는 약간 감소추세을 보이고 있다. 따라서 이 지역에 대한 각별한 보호와 분별있는 관광개발이 요망된다.

The depth and spread of root systems and the density of root branching affect the success and survival of plants subjected to drought. The type and size of root systems are controlled by heredity and soil conditions. There are also important interaction between roots and shoots; roots are dependent on shoots for carbohydrates, growth regulators, and certain vitamins, and shoots are dependent on roots for water, minerals, and certain growth regulators. Pinus thunbergii Parlatore had most of roots in the top 20cm of soil, and had little short of roots in the less than 80cm of soil. Average of root density was in the upper soil(0~20cm). Root density of Pinus thunbergii Parlatore was similar to that of Cryptomeria japonica. There is no saying that Pinus thunbergii Parlatore has an advantage over Cryptomeria japonica in the drought. This data will be used to the root density values in the simulation model of black pine stands.