• 한국작물학회지
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• 제53권3호
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• pp.292-296
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• 2008

Clay-coated rice seeds (clay-coated seeds A and B) were directly sown on dry paddy and their growth and yield were compared with the normal drill-sown seeds on dry flat paddy. In clay-coated seeds, germination was 1 day earlier and the emergence rate was higher up to 5% than that of normal drill-sown seeds. But the apparent number of seedling stand per $m^2$ was lower than that of normal drill-sown seeds, which is due to the smaller amount of seeding in clay-coated seeds. At the early growth stage, the plant height of clay-coated seeds A was taller than that of drill-sown seeds, while the plant height of clay-coated seeds B was 0.7 cm shorter than that of drill-sown seeds. At the late growth stage, however, the difference was insignificant in both cases. The maximum tillering stage was 10 days earlier in drill-sown seeds. Lodging index was the lowest in clay-coated seeds B and there was no difference between clay-coated seeds A and drill-sown seeds. The ratio of stem base weight, culm diameter and culm wall thickness were higher in clay-coated seeds, while the lower internodes (4th, 5th and 6th) length was shorter in claycoated seeds than in drill-sown seeds. In clay-coated seeds, the number of panicle per $m^2$ was smaller, while the number of spikelet per panicle was a little larger than in drill-sown seeds. The rate of ripened grain and brown rice 1,000 grain weight were lower in the clay-coated seeds, thus the yield was $98{\sim}99%$ level of drill-sown seeds. Considering that the amount of seeding in clay-coated seeds was two-thirds of that in drill-sown seeds, it is expected that clay coating method could become an additional technique for direct seeding cultivation.

• 한국초지조사료학회지
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• 제10권1호
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• pp.15-20
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• 1990

본 실험은 혼파초지에서 봄철 1차 이용시기와 1차 이용후 재생기간에 따른 목초의 일당 건물생산량, 경엽분포비율, 일반성분함량 및 세포벽 구성물질 등에 미치는 영향을 구명하고자 1차 이용시기(주구)를 영양생장기(초장 25-30cm), 절간신장기(초장 40~50cm) 및 출수기(초장 60~70cm)로 하고 1차 이용후 재생기간(세구)을 20, 30 및 40일로 하여 1987년도와 1988년도 2개년에 걸쳐 실시하였다. 1차 이용시 일당생산량은 늦게 이용할수록 증가하나 2차 이용후부터는 감소하여 1차 이용을 빨리 하는 것이 좋았으며, 재생기간은 건물생산량 측면에서 20일은 너무 짧고 40일은 너무 길어 30일이 가장 유리하였다. 목초 경엽분포비율은 1차 이용을 일찍 할수록, 1차 이용후 재생기간을 짧게 할수록 잎의 비율은 증가하고 줄기의 비율은 감소하여 사료가치는 증진되었다. 목장의 사료가치(일반성분함량과 제포벽구성물질)도 1차 이용을 영양생장기로 일찍 할수록, 1차 이용후 재생기간을 짧게 할수록 증가하였다. 조사자질생산량은 1차이용을 늦게 할수록 증가되었으나 2차 이용시부터는 상살되었으며, 재생기간 30일에서 조사자질생산량은 가장 많았다. 이상의 결과로서 초지에서 목초의 양호한 재생, 건물생산성, 수절생산성 및 사료가치 등을 고려해볼 때 봄철 1차 이용은 가급적 일찍하는 것이, 그리고 1차 이용후 재생기간은 1차 이용시기에 관계 없이 30일 정도로 하는 것이 가장 바람직하다고 생각된다.

• 토지주택연구
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• 제2권4호
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• pp.397-406
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• 2011

본 연구는 지속 가능한 주거환경을 구현하기 위한 실천전략의 하나로서 100년의 내구성과 가변성을 갖는 장수명 공동주택 표준모델에 실질적으로 적용할 수 있는 다양한 가변요소 시스템 개발을 주된 목적으로 한다. 연구방법으로는 장수명 공동주택 표준모델을 적용한 '실험주택'을 대상으로 개발한 각종 가변요소 시스템과 기술들을 통합하고 단계별 현장 적용성 평가, 전문가 의견조사 및 설문조사 등을 실시하였다. 본 연구는 총 3단계로 구분하여 수행하였다. 1단계에서는 고정요소인 전체 구조체와 가변요소인 건식외벽, 창호 등을 시공함과 동시에, 전용면적 $84m^2$에 가변요소 시스템을 시공하면서 현장 적용성을 평가하였다. 2단계에서는 전용면적 $50m^2$ 3세대를 대상으로 국내 최초로 수직통합형 세대(전용$50m^2$+전용$40m^2$)와 수평확장형 세대(전용$50m^2$+전용$10m^2$)를 대상으로 다양한 가변요소시스템의 현장 적용성 평가를 실시하였다. 3단계에서는 본 연구에서 개발한 건식 온돌의 현장검증을 위한 각종 성능평가 실험과 기 사용한 주택부품의 해체, 이동 및 재시공을 통한 3R 구현 정도 파악 등 실용성 제고를 위한 다양한 검증 작업도 함께 실시하였다.

• 한국환경과학회지
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• 제28권6호
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• pp.545-552
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• 2019

Tropaeolum majus, with a high decorative and food demand for vertical greening systems, has been utilized to revitalize urban agriculture. The effects of number of non-woven fabrics in a non-water environment and the adaptability of T. majus to this system were investigated. Planting ground composition of the container-type wall vertical greening system was made using non-woven fabric in one, two, three, or four layers. The results showed that the soil water content remained the highest when the non-woven fabric comprised 4 sheets. The morphological properties showed more growth with the 4 sheets than with 1, 2, and 3 sheets. In terms of physiological characteristics, chlorophyll content was mostly high in the 4 sheets, while shoot fresh weight value was in the order of 3 > 4 > 2 > 1 sheet, and root fresh weight value was in the order of 4 > 2 > 1 > 3 sheets. The dry weight of the measured values in the shoot was in the order of 4 > 3 > 2 > 1 sheet while no clear difference was found in the root of each treatment. The difference in the flowring characteristics was not different, but in evaluating the characteristics as a whole, the growth in the three layers of non-waven fabric was the best. In addition, the soil moisture contents and the growth characteristics were statistically significant as a positive correlation between the groups. Thus, greater the non-woven fabric, the higher is the adaptability of T. majus to dry stress under soil water-free conditions by maintaining soil moisture content. This showed that it represented an effective alternative as a method of vertical greening system for lower maintenance urban agriculture.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.1882-1887
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• 2007

In the present experimental study, the effect of interfacial tensions on pressure drop of air-water two-phase flow in round mini-channels was investigated. A glass (highly wettable) tube and a Teflon (poorly wettable) tube, both in 350 mm length but 1.8 mm and 1.59 mm in inner diameters each, were used for the tests. All the experiments were performed only in the plug flow regime, confirmed by visualization. In the glass tube, the gas plugs were surrounded by the liquid film along the inner periphery. On the other hand, the inner wall remained dry at the gas portion in the Teflon tube. The pressure drop of the plug flow in the Teflon tube without the liquid film) appeared much larger than in the glass tube (with the liquid film) due to dissipation of energy by movement of the wetting lines. In this paper, various correlations on the two-phase pressure drop of plug flows were compared and a modified correlation was proposed, taking account of the surface wettability.

• Asian-Australasian Journal of Animal Sciences
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• 제9권3호
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• pp.281-285
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• 1996

On farm demonstration of urea treatment (5 kg urea dissolved in 60 litre water/100kg) of straw was performed at 6 different sites and treated straw was stored by three different methods i.e., plastic covered, mud plastered and existing farmers technique (mud plastered on the top and open from sides) to determine the best storage method in field. Untreated and treated samples were taken after 5 week storage period and subjected to crude protein, crude fibre and cell wall constituents analysis. In situ dry matter digestibility of straw was measured by nylon bag technique in buffalo bulls. Crude protein content increased by 100 to 153 percent in treated straw stored by different methods. Maximum increase in crude protein of treated straw was noticed in mud plastered method. Urea treatment of straw resulted in significant decrease in crude fibre contents in all the storage methods. Treatment of straw enhanced the in situ digestibility by 25-49 percent and maximum digestibility (53%) was found in mud plastered storage method. It was concluded that the mud plastered storage method for urea treated straw was found to be the best at farm level.

• International journal of advanced smart convergence
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• 제4권1호
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• pp.120-126
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• 2015

This research is a comparison of the characteristics of the displacement isolines due to powder-die-wall friction that arise during the compaction of ceramic powders in conventional die. It has been done using the CosmosWorks software package of the SolidWorks simulation software. The results of comparative simulation with FEM showed that the comparison of the displacement isolines and distribution of deformation of the ceramic powders. In the case of conventional uniaxial dry compaction for long length cylindrical green compact, considerable bending of the layers in the form of a cone can be observed. It is symmetry along centerline of cylindrical green compact. The distributions of the deformation of the green compacts (diameter 14 mm, height 20 mm) as a result of conventional compaction under ultrasonic vibration with power 1 and 2 kW are reduced to 4% and 6.5% when compared with conventional compaction without ultrasonic vibration respectively. Thus, density distribution can be minimized by increasing the power of ultrasonic vibration.

• ETRI Journal
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• 제38권4호
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• pp.685-694
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• 2016

A surface micromachined piezoresistive pressure sensor with a novel internal substrate vacuum cavity was developed. The proposed internal substrate vacuum cavity is formed by selectively etching the silicon substrate under the sensing diaphragm. For the proposed cavity, a new fabrication process including a cavity side-wall formation, dry isotropic cavity etching, and cavity vacuum sealing was developed that is fully CMOS-compatible, low in cost, and reliable. The sensitivity of the fabricated pressure sensors is 2.80 mV/V/bar and 3.46 mV/V/bar for a rectangular and circular diaphragm, respectively, and the linearity is 0.39% and 0.16% for these two diaphragms. The temperature coefficient of the resistances of the polysilicon piezoresistor is 0.003% to 0.005% per degree of Celsius according to the sensor design. The temperature coefficient of the offset voltage at 1 atm is 0.0019 mV and 0.0051 mV per degree of Celsius for a rectangular and circular diaphragm, respectively. The measurement results demonstrate the feasibility of the proposed pressure sensor as a highly sensitive circuit-integrated pressure sensor.

• 한국환경과학회지
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• 제5권3호
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• pp.317-327
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• 1996

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Zinc-tolerant microorganism, such as Pseudomonas chlororaphis which possessed the ability to accumulate zinc, was isolated from industrial wastewaters polluted with various heavy metals. The characteristics of zinc accumulation in the cells, recovery of the zinc from the cells accumulating zinc, were investigated. Removal rate of zinc from the solution containing 100 mall of Zinc by zinc-tolerant microorganism was more than 90% at 48 hours after inoiulation of the microorganisms. A large number of the electron-dense granules were found mainly on thIn cell wall and membrane fractions, when determined by transmission electron microscope. Energy dispersive X- ray spectroscopy revealed that the electron-dense granules were zinc complex with the substances binding Heavy metals. The zinc accumulated into cells was not desorbed by distilled water, but more than 80% of the zinc accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at 55$0^{\circ}C$ amounted to about 21% of the dry weight of the cells. EDS analysis showed that the residues were comparatively pure zinc compounds containing more than 79% of zinc.

• 한국전기전자재료학회논문지
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• 제24권2호
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• pp.156-161
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• 2011

The present study introduces a novel wet etching technique for nanostructure fabrications which usually requires low surface roughness. Using the current method, acquired profiles were smooth even in the nanoscale, which cannot be easily achieved with conventional wet or dry etching methods. As one of the most popular single crystal silicon etchant, potassium hydroxide (KOH) solution was used as a base solvent and two additives, antimony trioxide (Sb2O3) and ethyl alcohol were employed in. Four experimental parameters, concentrations of KOH, Sb2O3, and ethyl alcohol and temperature were optimized at 60 wt.%, 0.003 wt.%, 10 v/v%, and $23^{\circ}C$, respectively. Effects of additives in KOH solution were investigated on the profiles in both (110) and (111) planes of single crystal silicon wafer. The preliminary results show that additives play a critical role to decrease etch rate significantly down to ~2 nm/min resulting in smooth side wall profiles on (111) plane and enhanced surface roughness.