http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 하명주 (검색결과 19 건)
- 무료
- 기관 내 무료
- 유료
-
-
-
-
하명주,남석우,한종희,윤성필,임태훈,홍성안 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1
고 에너지, 고 출력 밀도의 이동 전원이 요구되고, 휴대용 전자기기의 연속적 사용이 필요하게 되면서 대용량 배터리를 대신할 대체 연료전지의 수요가 증대됨이 기대되고 있다. 그러나 연료전지를 연속적으로 사용하기 위해서는 에너지 밀도가 높은 연료를 직접사용하거나 연료 개질기가 필요하다. 본 연구에서는 그 중에서 연료개질부분으로 반응 후 배출되는 미반응 수소와 공기의 산화반응에 의한 열을 이용하여 반응열과 기화열이 공급되도록 제작된 마이크로 반응기를 이용하여 메탄올 수증기 개질반응을 수행하였다. 메탄올은 물과 몰비로 1:1.5 (CH3OH:H2O)로 혼합한 수용액을 사용하였으며, 액체 펌프를 통해 기화기로 공급하였다. 기화기 또한 연소반응에서 공급되는 열을 이용하여 기화시켜반응기에 공급하였으며. 반응 후 가스는 GC를 이용하여 분석하였다. 사용된 개질 촉매는 Cu계열의 상용촉매이며, 연소용으로는 세리아로 코팅을 한 니켈판에 Pd, Pt 담지한 촉매를 이용하였다, 반응온도 250~300℃, 공간속도 6,000h-1에서 메탄올 수증기 개질 실험을 수행하였다. 수소 공급 속도에 따른 연소부의 온도 분포와 개질기의 시동 속도 등을 측정했으며. 또한 그에 따른 개질부의 반응변화와 그 성능을 측정하였다.
-
-
하명주(Myeong Ju Ha),윤성필(Sung Pil Yoon),한종희(Jonghee Han),임태훈(Tae-Hoon Lim),김우식(Woo Sik Kim),남석우(Suk Woo Nam) 한국청정기술학회 2020 청정기술 Vol.26 No.4
재생에너지로부터 수전해를 통하여 생산된 수소와 포집된 CO₂를 활용하여 메탄올을 합성하는 power-to-methanol 기술이 재생에너지를 대용량으로 저장하는 방안으로 제시되고 있다. 본 연구에서는 메탄올을 수소 및 전력 생산에 활용함에 있어 더욱 효율적인 방법으로 연료전지 내부에서 메탄올 수증기개질 반응이 일어나는 내부개질형 용융탄산염 연료전지에 대해 성능 분석을 실시하였다. 용융탄산염 연료전지의 연료극으로 사용되는 다공성 Ni-10 wt%Cr을 촉매로 메탄올 수증기개질 반응을 수행한 결과 연료전지 운전 조건에서 연료극은 메탄올 수증기개질 반응에 충분한 활성을 나타내었다. 메탄올 수용액을 직접 용융탄산염 연료전지의 연료극으로 공급한 결과 연료전지의 성능은 외부 개질기를 통하여 생산된 개질가스를 공급하는 경우에 비해 다소 성능이 낮게 나타났으며, 메탄올 공급유량이 비교적 낮은 경우 고 전류밀도에서 불안정한 성능을 나타내었다. 연료극으로부터 생성된 가스를 재순환시킴으로써 연료전지의 성능을 향상시킬 수 있었으며, 메탄올 전환율도 90% 이상 얻을 수 있었다. 물질수지를 통하여 연료극에서 일어나는 반응을 분석한 결과 전류밀도 및 가스 재순환 유량이 증가함에 따라 메탄올 수증기개질 반응속도가 증가함을 확인하였다. 이상의 결과로부터 별도의 촉매층을 설치할 필요 없이 연료극 만으로도 용융탄산염 연료전지 내에서 메탄올 수증기개질 반응이 가능하며, 메탄올 내부개질형 용융탄산염 연료전지를 통하여 전력과 합성가스를 동시에 생산할 수 있음을 확인하였다. Methanol synthesized from renewable hydrogen and captured CO₂ has recently attracted great interest as a sustainable energy carrier for large-scale renewable energy storage. In this study, molten carbonate fuel cell’s performance was investigated with the direct conversion of methanol into syngas inside the anode chamber of the cell. The internal reforming of methanol may significantly improve system efficiency since the heat generated from the electrochemical reaction can be used directly for the endothermic reforming reaction. The porous Ni-10 wt%Cr anode was sufficient for the methanol steam reforming reaction under the fuel cell operating condition. The direct supply of methanol into the anode chamber resulted in somewhat lower cell performance, especially at high current density. Recycling of the product gas into the anode gas inlet significantly improved the cell performance. The analysis based on material balance revealed that, with increasing current density and gas recycling ratio, the methanol steam reforming reaction rate likewise increased. A methanol conversion more significant than 90% was achieved with gas recycling. The results showed the feasibility of electricity and syngas co-production using the molten carbonate fuel cell. Further research is needed to optimize the fuel cell operating conditions for simultaneous production of electricity and syngas, considering both material and energy balances in the fuel cell.
-
河明珠 대한보건협회 1985 대한보건연구 Vol.11 No.2
The present study was aimed at to find family characteristics, food habits, physical exercise and other factors related to obesity among the elementary school children in Seoul. The data used in this study were collected from both 203 obese students as a study group and 203 normal students as a control group according to their relative body weight. In addition, the data were also collected from 391 mothers of both groups of stu´dents to complement students' data. The survey for the present study was conducted from June 19 to July 13, 1984. The major findings are summarized as follows: 1. Observed from the relative body weight, 203 subjects, 9.9% of the 2,052 subjects turned out to be obese. 2. Family Characteristics (1) Considering about weaning history, 53.3% of the control group had been breast · fed before the introduction of supplementary foods, which was higher than that of the study group, 44. 4%(P<0.05). 49.5% of the study group were weaned at the age of 4~6 months, while 48.5% of the control group at the age of 7~12 months(P<0.05). The result showed that the termination of breast-fed of the study group was earlier than that of the control group. (2) Considering about physical growth of family, in the study group 34.0% of fathers, 28.1% of mothers and 43.9% of brothers and/or sisters were overweight or obesity, while in the control group 15.8% of fathers, 8.9% of mothers and 7.4% of brothers and/or sisters were overweight or obesity (P<0.001). (3) Considering about physical growth and development, the mean height of the study group were 139.2cm in boys and 138.5cm in girls, while that of the control group were 132.5cm in boys and 131.9cm in girls. The mean weight of the study group were 42.0kg in boys and 40.1kg in girls, while that of the control group were 27.2kg in boys and 26.9kg in girls. Various indices of nutrition such as relative weight, Ro‥hrer index, Kaup index were determined. 3. Investigation into food habits (1) Considering about food preference, it showed no remarkable differences between both groups. In case butter, even though it was not a favorite food, 34.0% of the study group and 27.6% of the control group liked it, which was revealed that the study group liked better than the control group. Considering about taste preference, the study group liked sweet taste more than the control group. (2) Considering about food behavior, 68.5% of the study group and 85.1% of the control group had three times of meals a day, which showed tendency towards skipping meals in the study group was higher than that in the control group(P<0.001). As far meal quantities, the study group took more than the control group(P<0.001). (3) Considering about snacking behavior, the mean frequency of snacking was 2.1 times per day in the study group while 2.5 times per day in the control group. Especially, in case of sweets and chocholates, 53.7% of the study group and 64.5% of the control group took frequently(P<0.05). 4. Physical Exercise (1) Considering about physical exercise performance of both groups, 60.6% of the study group and 67.0% of the control group exercised regularly and favorate exercises were rope-skipping and running in both groups. As far quantities of exercise, 28.1% of the study group and 26.1% of the control group similarly exercised every day. (2) Considering about preference towards exercise, 21.3% of the study group and 8.9% of the control group disliked physical education(P<0.01). 5. Mother's Attention to their Children's Health Management (1) Considering about attention to food behavior. it revealed that mothers of the study group restricted quantity of food more severe than mothers of the control group(P<0.001). (2) Considering about attention to nutrition and exercise, 23.3% of the study group and 42.0% of the control group took nutrients(P<0.001) and the most used one was the vitamines. Considering about physical exercise, it revealed that mothers of the study group took more attentions than mothers of the control group(P<0.001). Educational backgrounds of mothers were higher, mothers obtained knowledge about health through newspapers or books rather than T.V. or radio(P<0.001).
-
-
-
ScienceON연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
