• 제목/요약/키워드: Energy contents

검색결과 2,176건 처리시간 0.027초

Preparation of Bipolar Plate for Fuel Cell Using CNT/Graphite Nano-Composite

  • Choi, Jong-Min;Kim, Tae-Jin;Hyun, Min-Soo;Peck, Dong-Hyun;Kim, Sang-Kyung;Lee, Byung-Rok;Park, Jong-Soo;Jung, Doo-Hwan
    • Carbon letters
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    • 제6권3호
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    • pp.181-187
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    • 2005
  • Bipolar plates require some specific properties such as electrical conductivity, mechanical strength, chemical stability, and low permeability for the fuel cell application. This study investigated the effects of carbon nanotube (CNT) contents and process conditions of hot press molding on the electrical and physical properties using CNT 3~7 wt% added graphite nano-composites in the curing temperatures range of 140~$200^{\circ}C$ and pressure of 200~300 kg/$cm^2$. Bulk density, hardness and flexural strength increased with increasing CNT contents, curing pressure and temperature. With the 7 wt% CNT added noncomposite, the electrical resistance improved by 30% and the flexural strength increased by 25% as compared to that without CNT at the temperature of $160^{\circ}C$ and pressure of 300 kg/$cm^2$. These properties were close to the DOE reference criteria as bulk resistance of 13 $m{\Omega}cm$ and tensile strength of 515 kg/$cm^2$.

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투명 디스플레이 실현을 위한 상부 전극용 TCO 박막제조 및 특성 분석 (A Study on TCO thin film for transparent display upper electrode)

  • 김은서;박형준;김호운;김해문;박진수;김영은;김인수
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2014년도 추계 종합학술대회 논문집
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    • pp.253-254
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    • 2014
  • 본 연구에서는 DC magnetron sputter 장비를 사용하여 투명 디스플레이 실현을 위한 상부전극용 박막을 제작하였고, 제작된 박막의 광학적 특성과 물리적 특성을 분석하였다. 소다라임 유리기판 인가된 전판 위에 증착한 ITO의 경우에는 박막의 증착률압에 따라 두께와 굴절률이 증가함을 보였으며, 증착된 박막의 광학적 투과도는 박막의 두께에 따라 접차 감소함을 확인 하였고, 반면 고전도 특성을 가진 알루미늄 박막은 증착된 박막의 두께가 두꺼울수록 전면의 반사도가 증가하여 투명전극으로 사용할 수 없었으나 스퍼터의 내부의 분위기압을 높이고 인가된 전압을 높고 단시간에 박막을 증착하였을 경우에 약 70%정도 현재 보다 향상된 투명전극으로의 광학적 투과도 특성을 보였다.

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저선회 연소기에서 합성천연가스(SNG) 연료의 수소함량에 따른 연소 특성 연구 (A Study on the Combustion Characteristics with Hydrogen Contents of SNG Fuel in Low-Swirl Combustor)

  • 정황희;강기중;이기만
    • 한국수소및신에너지학회논문집
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    • 제28권2호
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    • pp.181-189
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    • 2017
  • This paper describes experimental results on combustion characteristics with hydrogen contents of synthetic natural gas (SNG) in low swirl combustor. To investigate the effect of hydrogen contents for premixed SNG flame, stability map, CH chemiluminescence images, flame spectrum analysis and emission performances were measured. In the results, as the hydrogen content was increased, the lean flammable limit was expanded and the flame length was decreased. The hydrogen contents affected the flame liftoff height, and it has different tendency according to the equivalence ratio and flame shape. The change of height and length of flame according to hydrogen contents is caused by the fast burning velocity of hydrogen, which can be confirmed by GRI 3.0 reaction mechanism in PREMIX code. The intensity of $OH^*$, $CH^*$ and $C_2^*$ was confirmed by spectrum analysis of flame. As a result, the $CH^*$ intensity was not significantly different according to hydrogen content. The increase of hydrogen contents influenced positively CO and NOx emission performances.

시판 도시락의 영양평가 및 품질관리 방안에 관한 연구 (Evaluation of Nutritional Quality of Packaged MealsProduced by Packaged Meal Manufactures in Seoul and Kyungki-do)

  • 계승희
    • Journal of Nutrition and Health
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    • 제22권3호
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    • pp.149-158
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    • 1989
  • To investigate the nutritional quality of packaged meals produced by packaged meal manufactures, a nutritional evaluation was conduced. Samples examined in this study were 95 Products which composed of 86 Doraks, 7 Kimplabs and 2 Yubuchopabs Produced in packaged meal manufactures in Seoul City and Kungki-do province The distribution of food groups showed that amounts of animal foods were abound, but amounts of green vegetables, limited in Dosirak comparing to one meal RDA levels. Amounts of meats, fishes and shells are increased more than amounts of egged and legumina with increase of price of Dosirak. The total kinds of food and the amounts of certain food in Kimpab and Yubuchopab were lower than Dosirak. The energy and protein contents of Dosirak were found to be higher than one meal RDA levels, with exception of protein content in Dosirak of the price 1000 won. The contents of energy and protein in Kimpab and Yubuchopab are less than one meal RDA levels. Calcium and iron contents in Dosirak, and calcium content in Yubuchopab were present in excess compared to the one meal RDA. However, In Kimpab, calcium and iron contents were lower than the one meal RDA. On the whole, vitamin contents of Dosirak were sufficient whereas vitamin contents of Kimpab and Yubuchopab were lower than the one meal RDA. Number of side dishes used in Dosirak were 6-23 items depending on prices. Guidelines were suggested for effective nutritional quality control of packaged meals.

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제6차 및 제7차 초등학교 과학과 교육과정에서의 STS 내용 비교 (Comparative Analysis on the STS Contents of the 6th and 7th primary Science Curriculum)

  • 권치순
    • 대한지구과학교육학회지
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    • 제3권1호
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    • pp.9-17
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    • 2010
  • This study was carried out to examine the tendency about the relative importance of STS education of the 6th and 7th primary science curriculum. The results of the research are as follows. Primary science textbooks in the 6th curriculum, average 13.3% of the total pages was assigned to STS contents but it is increased to 24.2% in the science textbooks of the 7th curriculum. STS constituents of the 6th primary science textbooks come out orderly applications of scientific knowledge(47.1%), relevance of a community(40%), social problems and issues(11.8%). Of the 7th science textbooks, the contents about applications of scientific knowledge amount to 67.1% of the total STS constituent and relevance of a community(32.2%) rank behind it. The contents of other components are not enough. The 6th science textbooks contents about the effect of technological development amount to 35.3% of the total STS subject area, and environmental quality(20.0%), natural resource(15.2%), energy(11.8%), sociology of science(11.8%) ranks behind it. In the 7th science textbooks ranking is the effect of technological development(42.3%), natural resource(17.3%), energy(12.5%), sociology of science(12.5%), environmental quality(20.0%). There are few contents about population, human engineering and space research and national defense in the science textbooks.

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실시간 운영체제를 위한 저전력 GUI 설계 및 구현 (Design and Implementation of Low-Power GUI for Real-Time Operating System)

  • 정재엽;이철훈
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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    • pp.817-821
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    • 2007
  • 제한된 배터리를 가지고 있는 내장형 시스템에서 전력을 최소화하여 제한된 전력을 오랫동안 사용하는 기술은 중요한 문제로 인식되어 왔다. 최근 내장형 시스템은 대형 TFT-LCD와 터치스크린을 장착하면서 그에 따른 전력소비가 더 증가하고 있다. 본 논문에서는 GUI에서 전력소모를 감소할 수 있는 방안인 프레임버퍼 모니터링을 연구하였다. 프레임버퍼 모니터링 기법은 화면의 퀄리티(Quality)를 보장하는 범위 내에서 Refresh-rate과 Backlight을 조절하여 LCD에서 전력 소모를 줄이는 방법이다.

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태양광 기술을 적용한 공중 화장실 디자인 제안 (Proposal of a New Public Toilet Design using Solar Energy)

  • 박진희;구은희
    • 한국콘텐츠학회논문지
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    • 제10권2호
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    • pp.215-223
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    • 2010
  • 산업혁명 이후 인류의 화석연료 사용 증가에 따른 이산화탄소($CO_2$) 배출 확대로 온실가스가 지구 온난화의 주된 원인으로 밝혀지면서 선진국을 중심으로 세계 각국들은 온실가스 감축을 위해 경제 개발 도시 환경 정책 등 다양한 분야와 적극적으로 결합하여 신재생 에너지 - 태양광 기술을 이용한 디자인 요구가 급증되고 있다. 따라서 본 연구에서는 이러한 문제를 해결하기 위한 대안의 하나로 태양광 기술을 적용한 공중화장실을 제시하고자 한다.

Comparison of Daily Soil Water Contents Obtained by Energy Balance-Water Budget Approach and TDR

  • Rim, Chang-Soo
    • Korean Journal of Hydrosciences
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    • 제8권
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    • pp.57-68
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    • 1997
  • The daily soil water contents were obtained from the time domain reflectometry(TDR) method and energy balance-water budget approach with eddy correlation at the two small semiarid watersheds of Lucky Hills and Kendall during the summer rainy period. There was a comaprison of daily soil water content measured and estimated from these two different approaches. The comparison is valuable to evaluate the accuracy of current soil water content measuring system using TDR and energy balance-water budget approach using eddy correlation method at a small watershed scale. The degree of simiarity between the regressions of these two methods of measuring soil water content was explained by determining the correlations between these methods. Simple linear regression analyses showed that soil water content measured from TDR method was responsible for 58% and 63% of the variations estimated from energy balance-water budget approach with edy correlation at Lucky Hills and Kendall, respectively. The scatter plots and the regression analyses revealed that two different approaches for soil water content measurement at a small watershed scale have no significant difference.

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