• 생태와환경
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• 제40권2호
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• pp.352-356
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• 2007

The effects of food concentration (Chlorella vulgaris) and predator (Pseudorasbora parva) density on the distributional pattern of Daphnia pulex was evaluated in observation chambers. It was found that in the chamber with higher food concentration, Daphnia began to aggregate and formed tighter swarms. The close distance between each individual and distance from the center of swarm were observed in higher food conditions however, this distributional pattern was not seen in the chamber without food. Thus it suggests that the food is necessary for the swarming behavior of Boptnia in natural habitat. The swarming developed regardless of predator existence and the predator density did not affect swarming pattern of Daphnia.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.56-56
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• 2011

알코올 환원법(alcohol reducing process)은 화학적 환원제가 필요하지 않은 화학합성법으로 메탄올, 에탄올, 프로판올, 이소프로판올, 부탄올 등 C1-C4의 알코올류, 에틸렌 글라이콜, 디에틸렌 글라이콜, 프로필렌 글라이콜과 같은 글리콜류 등이 용매이자 환원제로써 사용된다. 전형적으로 금속 전구체를 상기의 알코올류나 글리콜류에 용해 또는 분산시킨 후 그 용액을 환류 조건하에서 가열하게 되면 금속 이온과 용매간의 산화, 환원반응에 의하여 금속이온이 금속원자로 환원되며, 환원된 금속 입자들은 핵 행성과 성장 과정을 거쳐서 입자를 형성하게 된다. 본 연구에서는 알코올환원법을 이용하여 나노크기의 은입자제조를 시도하였고, 이를 PET 칩과의 마스터배치 제조을 시도하였으며, 이의 항균성능을 연구 고찰하였다. 30 ~ 80 nm의 은파우더를 제조할 수 있었으며, 우수한 항균성능을 갖는 Ag/PET 마스터배치를 제조할 수 있었다. 이를 활용하여 나노은입자기반의 항균섬유을 제조하여 이를 활용한 기모경편성물 제조의 기초데이타로 활용이 가능하리라고 사료된다.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제44차 학술발표회
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• pp.86-86
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• 2011

나노소재기술은 기존 소재로는 얻을 수 없는 새로운 기능 및 특성을 나타낼 수 있어 산업전반에 적용할 수 있는 최첨단집적기술이다. 그러나 나노입자를 섬유에 첨가하여 기능성 섬유를 생산하는 경우 응집이 발생하는 등의 다양한 문제점이 발생하는데 이를 극복하기 위해서는 사이즈 분포를 제어하는 기술, 표면처리를 통해 분산성을 향상시키는 기술, 나노입자와 섬유와의 상용성을 개선하는 기술 등이 해결되어야 한다. 본 연구에서는 고기능성 및 고부가가치 경편파일 니트 원단을 개발하기 위해 은(Silver) 나노입자가 균일하게 분산된 M/B(Master Batch)를 제조하였으며, 이를 PET와의 용융 혼합 방사함으로써 0.5denier(75D/144F)급 원사에 99.9%의 영구적인 항균/소취 기능을 부여하였다. 또한 개발된 극세사를 이용하여 다양한 경편파일 원단을 설계하고, 기모, 염색 및 날염 등의 공정을 거쳐 나노기술융합형 화학섬유소재를 이용한 기능성 침장 제품을 개발하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.961-965
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• 1992

It is well-known that shock waves frequently occur inside the nozzle of the interrupter, and that they play important roles in the arc interruption. A model interrupter with two-dimensional dual-airflow nozzles was used for this experiment. The arc was ignited with 1.4 mil copper wire stretched between the electrodes which were spaced out 56 mm. The arc current of 60 to 230 A was achieved by adjusting the external resistance from 5.5 to 1.6 ohms. The arc tests have been conducted for investigating the air arc characteristics, and the effects of shock waves and nozzle pressure ratios on the arc voltage, the arc resistance, the arc power, and average electric field. The results of these tests have been analyzed to provide insights into the arc characteristics for gas circuit breakers. The average electric field is represented by the function of the arc current to show the negative E-I characteristic explicitly. The effects of shock waves and nozzle pressure ratios are shown to be significant for a circuit breaker performance.

• 한국항공운항학회지
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• 제24권4호
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• pp.35-43
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• 2016

UAV has been promoted for practical use in the field of civilian and military. Recently, UAV is required high-specification performance such as long-term flight and precision observation. Among these UAVs, High Altitude Long Endurance UAV(HALE UAV) has been developed for the purpose to replace some of the functions of the satellite such as meteorological observation, communications and internet relay while flying a long period in the stratosphere. In order to fly a long period in harsh environment of the stratosphere, aircraft needs high Lift-Drag-Ratio and weight reduction of the structure. This paper performed the structural analysis for fuselage and empennage of HALE UAV. Critical loading conditions for structural analysis are acquired from flight load analysis and finally the results of structural sizing for weight reduction is presented.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.191-192
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• 2002

Since capsaicin was found as an excellent vanilloid receptor agonist, considerable efforts toward the development of a novel analgesic have been continued. However, the small therapeutic window between these effects and the excitatory side effects, such as hypothermia, bronchoconstriction, increased GI mobility, and hypertension, precluded the development of capsaicin as a systemic agent. (omitted)

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1466-1469
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• 2008

We have fabricated 2.5 inch QQCIF AM-OLED panel driven by ZnO-TFT on a plastic substrate for the first time. The number of photo mask for the whole panel process was 5 and the TFT structure was top gate with active protection layer as a first gate insulator. Optimizing the process for the substrate buffer layer, active layer, ZnO protection layer, and gate insulator was key factor to achieve the TFT performance enough to drive OLED. The ZnO TFT has mobility of $5.4\;cm^2/V.s$, turn on voltage of -6.8 V, sub-threshold swing of 0.39 V/decade, and on/off ratio of $1.7{\times}10^9$. Although whole process temperature is below $150^{\circ}C$ to be suitable for the plastic substrate, performance of ZnO TFT was comparable to that fabricated at higher temperature on the glass.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.202-202
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• 2008

The world gross market of many kinds of electronics, such as TV and mobile phone has been increasing rapidly these days. It is mainly caused by the amazing developments of IT technology during past decade and the changes of individual life style for the better. Thanks to the increases of electronics manufactured in quantity, much more electronic components such as MLCC (multi layer ceramic capacitor) and PCB (printed circuit board), which are our main products, have been needed as a consequence. Though it was reported that total market of electronic components exceeds several hundreds of billion dollars, there are many manufactures struggling for survival in the competition of electronics components. Then the recognition of quality as a key technology has spread and the efforts for high-yield production lines have been kept in many companies. In this paper, our efforts to eliminate the contamination of particles and the diffusion of some volatile organic compounds which is very harmful to workers at production line have been introduced.

• 천문학회보
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• 제37권1호
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• pp.70.2-70.2
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• 2012

The night sky in Mongolia is known to be one of the darkest and clearest in Asia. The seasonal dust winds from the Gobi desert, however, might degrade the transparency of the night sky and affect the photometrical quality for astronomical research. In this poster, we present the preliminary results of the first transparency measurement of the night sky in Monglia. The observations are done at Zuunmod located at 25 km south from Ulaanbaatar in 2011 October 26-31. We used a CCD camera (QSI 583s) attached to an 80 mm aperture refractor telescope (William Optics Zentih Star 80 II ED APO). A new supernova, SN2011fe, and a young stellar object, HBC 722, were monitored in order to measure the extinction coefficients. These values in Mongolia are compared with those in other astronomical observatory.

• 공업화학
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• 제8권4호
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• pp.617-623
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• 1997

폴리솔베이트-핵산올-물의 3성분계의 상거동에 관한 메카니즘을 조사한 것으로, 등방성인 미셀영역에서 비등방성인 모자이크 액정상을 편광현미경에 의해 관찰하였다. 액정상 및 다른 상들은 약 20~70 wt% 범위에서 관측되었으며, 이 영역에서는 보다 안정한 유화계나 분산계의 포뮬레이션에 대한 기본적인 데이터를 제공할 수 있다. 알킬기의 탄소수 증가에 따라 3상 영역이 감소한 반면에, 2상 영역이 증가되었으며 비등방성 액정상은 관찰되지 않았다.