• Journal of Biosystems Engineering
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• 제25권6호
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• pp.489-496
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• 2000

This study was conducted in order to find an ideal working fluid kind and a proper filling amount in the heat pipe as well as an inclined angle of heat pipe when they are placed to recover exhaust gas heat in the hot air heater. Followings are the findings of this research. 1. Of the four different working fluids-gasoline kerosene distilled water and acetone-acetone filled heat pipe showed the best performance giving out more homogeneous temperature profile on the radiating part than the kerosene and gasoline heat pipe an carrying out heat transmitting function better than the distilled water heat pipe by 10~2$0^{\circ}C$ higher on the radiating part. Acetone would be a good choice for recycling of exhaust gas heat in the hot air heater. 2. Of the filling amount of working fluid inside the heat pipes dry-out situations possible caused by insufficient filling were found in the filling amount of 5, 7.5 and 10% heat pipes as heat supply rate increases gradually in the range of 50 to 15kJ/sec. but no dry-out and stabilized heat transmitting performance occurred in the heat pipes of 12.5 and 15% filling at the same heat supply rate. It recommends that filling amount shall exceed 12.5% at least with the working fluids of this experiment. 3. The test revealed that the heat transmitting performance of heat pipe was more affected by filling amount rather than inclined angle.

• 한국작물학회지
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• 제33권1호
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• pp.81-86
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• 1988

왕골 육종을 위한 형질상호간의 유전관계를 조기에 추정하고 효율적인 선발을 위한 기초자료를 얻고자 국내수집종 64품종을 공시하여 유전력, 표현형상관, 유전상관, 환경상관을 조사한 결과를 요약하면 다음과 같다. 1. 7개 형질에 대한 유전력 중 대부분의 형질에서는 높았으나 건피수량에서 만은 다소 낮게 평가되었다. 2. 형질상호간의 상관관계는 경장은 건수중과 건피수량에서, 경의 직경 역시 건수중과 건피수량에서 가장 높은 유의차로 정의 상관을 보였다. 3. 수량과 타형질과의 상관이 가장 높았든 형질은 경장, 경의 직경, 건수중이었으며 경로계수의 분석결과도 이들 형질의 직접효과가 가장 높았다.

• 한국대기환경학회지
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• 제14권3호
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• pp.191-208
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• 1998

Estimations of dry and wet depositions in Korea and the size distributions of yellow sand above Korea have been carried out using the Eulerian aerosol model with the simulated meteorological data from the SNU mesoscale meteorological model. The estimated particle size distribution in Korea shows a bimodal distribution with peak values at 0.6 pm and 7 pm and a minimum at 2 pm in the lower layer However, as higher up, the bimodal distribution becomes an unimodal distribution with a peak value at 4∼5mm. Among the total amount of yellow sand deflated in the source regions , the dry and wet deposition fluxes were about 92%, and about 1.3∼0.5%, repectively, and the rest(5∼6%) is suspended in the air, Most of dust lifted in the air during the clear weather is deposited in the vicinity of the source regions by dry deposition and the rest undergoes the long -range transport with a gradual removal by the wet deposition processes. Over Korean peninsula, the total amount of yellow sand suspended in the air was about 6∼8% of the emissions in the source region and the dry and wet deposition fluxes were about 0.005∼0.7% and 0.003∼0.051% of the total emitted amount, repectively. It is estimated that 2.7∼8.9 mesa-tons of yellow sand is transported annually over the Korean peninsula with the annual mean dry deposition of 2.1∼490 kilo-tons and the annual mean wet deposition of 1.5∼65 kilo-tons.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.26-31
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• 2023

We investigated the impact of NF₃ / H₂O remote plasma dry cleaning conditions on the SiO₂ etching rate at different preparation states during the fabrication of ultra-large-scale integration (ULSI) devices. This included consideration of factors like Si crystal orientation prior to oxidation and three-dimensional structures. The dry cleaning process were carried out varying the parameters of pressure, NF₃ flow rate, and H₂O flow rate. We found that the pressure had an effective role in controlling anisotropic etching when a thin SiO₂ layer was situated between Si₃N₄ and Si layers in a multilayer trench structure. Based on these observations, we would like to provide further guidelines for implementing the dry cleaning process in the fabrication of semiconductor devices having 3D structures.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1259-1260
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• 2006

Intensive technological research on the Dry-bag CIP equipment was carried out to improve the dimensional accuracy and the productivity. The rubber mold design technology using FEM simulation during pressing was introduced, in order to achieve higher dimensional preciseness, and criteria for the selection of the In-line type or Off-line type, were established based on the powder flowability index proposed by Carr. Based on these research results, high productivity Off-line Dry-bag CIP equipment, which can realize good dimensional accuracy with high productivity, was developed even for non-granulated powders with poor packing density.

• 설비공학논문집
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• 제13권11호
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• pp.1049-1058
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• 2001

The performance and design analysis for a NWD cooling tower using a combined wet and dry type fill are numerically investigated and compared with the experimental results. The Stoecker's method is applied to the wet section and LMTD or NTU-Effectiveness method to the wet and dry sections. The efficiency ratio of the NWD cooling tower to a wet type crossflow cooling tower is 59.34%. The predicted result shows a good agreement with the experimental data within 1.4% error. Plume abatement is far better with a NWD cooling tower than a counterflow cooling tower. It costs less than a conventional wet/dry tower because the finned exchanger is eliminated. This method also leaves out complexity in structure and Intricacy in operation.

• 센서학회지
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• 제15권4호
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• pp.245-250
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• 2006

In this paper, glass cap wafer for MEMS device package is fabricated by using sand blaster dry etcher and Its surface is studied. The surface of dry etched glass is analyzed by using SEM, and many glass particles and micro cracks are observed. If these kind of particles were dropped from glass to the surface of device, It would make critical failure to the operation of device. So, several cleaning and etching methods are induced to remove these kinds of dormant failure mode and optimized condition is found out.

• Computers and Concrete
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• 제23권4호
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• pp.267-272
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• 2019

In order to study the effect of moisture on the compressive strength of low-strength hollow concrete blocks, an experimental study was carried out on 96 samples of locally manufactured hollow concrete blocks collected from three different locations. Uniaxial compression tests were conducted on dry specimens and three types of saturated specimens with moisture contents of 30%, 50% and 80% respectively. The range of moisture content adopted covered the range within which the concrete block samples are saturated in the dry and monsoon seasons. The compressive strength of low-strength hollow concrete blocks decreases with increase in moisture content and the relationship between compressive strength of hollow concrete blocks and their moisture content can be considered to be linear. However, the strength degradation of 30% moist concrete blocks with respect to dry blocks is relatively low and can be considered to be comparable to dry concrete blocks. A formula indicating the relationship between the moisture content and compressive strength of low-strength hollow concrete blocks is also proposed.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1034-1043
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• 2014

This study determined the effect of light intensity and photoperiod on the dry cell weight and total amount of carotenoids in four isolates of purple non-sulfur bacteria obtained from shaded and exposed microhabitats of a mangrove ecosystem in Kota Kinabalu, Sabah, Malaysia. The initial isolation of the bacteria was carried out using synthetic 112 medium under anaerobic conditions (2.5 klx) at $30{\pm}2^{\circ}C$. On the basis of colony appearance, cell morphology, gram staining, motility test, and 16S rRNA gene sequencing analyses, all four bacteria were identified as Afifella marina. One of the bacterial isolates, designated as Af. marina strain ME, which was extracted from an exposed mud habitat within the mangrove ecosystem, showed the highest yield in dry cell weight ($4.32{\pm}0.03g/l$) as well as total carotenoids ($0.783{\pm}0.002mg/g$ dry cell weight). These values were significantly higher than those for dry cell weight ($3.77{\pm}0.02g/l$) and total carotenoid content ($0.706{\pm}0.008mg/g$) produced by the isolates from shaded habitats. Further analysis of the effect of 10 levels of light intensity on the growth characteristics of Af. marina strain ME showed that the optimum production of dry cell weight and total carotenoids was achieved at different light intensities and incubation periods. The bacterium produced the highest dry cell weight of 4.98 g/l at 3 klx in 72 h incubation, but the carotenoid production of 0.783 mg/g was achieved at 2.5 klx in 48 h incubation. Subsequent analysis of the effect of photoperiod on the production of dry cell weight and total carotenoids at optimum light intensities (3 and 2.5 klx, respectively) revealed that 18 and 24 h were the optimum photoperiods for the production of dry cell weight and total carotenoids, respectively. The unique growth characteristics of the Af. marina strain ME can be exploited for biotechnology applications.

• 한국유기농업학회지
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• 제4권1호
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• pp.75-84
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• 1995

This study was carried out to find the effects of the mixtures of earthworm cast, peatmoss, and vermiculite as a vegetable plant growth medium on the growth pepper seedlings. The mixed ratios of earthworm cast-peatmoss-vermiculite were 40-20-40, 40-30-30, 40-40-40, 50-20-30, 50-30-20, 60-10-30, 60-20-20 and 60-30-10%. The results of the study are as follows: 1, There was a significant difference of plant length, leaf area, shoot dry weight, root dry weight and biological yield per plant for growth stages and mixed ratios(p<0.05). But there was no significant interactions for both of them. 2. The nursery soil with earthworm cast was generally higher than the control treatment in shoot dry weight, root dry weight adn biological yield per plant. The shoot dry weight and biological yield per plant were high in the treatment including 60% of the earthworm cast to the 3rd week and in the one including 50% from the 4th week. But in root dry weight, the treatment including 40% of it was higher than treatment of the others. 3. The shoot dry weight per plant in treatments consisting both of 40% of earthworm, 40% of peatmoss and 20% of vermiculite and of 60%, 10% and 30% was more significant than that in the control treatment(p<0.05). 4. The average relative growth rates of shoot dry weight, root dry weight and biological yield for all treatments were higher than the ratio of control treatment except the ration of the treatment consisting of 60% of earthworm, 20% of peatmoss and 20% of vermiculite.