• 제목/요약/키워드: CHE

검색결과 1,125건 처리시간 0.026초

진공복사관식 집열기의 성능실측 및 최적화 연구 (Study on the Optical Performance of Evacuated Solar Collectors)

  • 천원기;강상훈;김기홍;이용국;장래웅
    • 한국태양에너지학회 논문집
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    • 제21권4호
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    • pp.63-71
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    • 2001
  • This work has been carried out to find the ideal operating conditions for solar vacuum tube collectors which are widely used at present. Various types of solar collectors including a flat plate one were experimentally tested and examined to determine their thermal efficiencies and operating characteristics. Generally, solar vacuum tubes can be classified into two groups according to their design features. Of these, one is characterized by the insertion of a metallic device(such as a finned heat pipe) in an evacuated glass tube for the collection and transportation of solar energy. The other utilizes double glass tubes where the smaller one is contained inside the bigger one and soldered to each other after the small gap between them is evacuated. Both of these solar collectors are designed to minimize convection heat losses by removing the air which is in direct contact with the absorber surface. The performance of the former type can be readily analyzed by applying the relevant correlations developed for flat plate solar collectors. This has been demonstrated in the present study for the case of a solar collector where a heat pipe is inserted in an evacuated tube.

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노인의 무력감 지각 정도에 관한 연구 (A study on the degree of perceived powerlessness of the elderly)

  • 박인혜;이정희;강기선;권혜진;김경희
    • 지역사회간호학회지
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    • 제8권1호
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    • pp.61-73
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    • 1997
  • The purpose of this study was to identify the degree of perceived powerlessness and the factors which influence the powerlessness of the elderly. Data were collected by self-reported structured questionnare from 210 subjects living in Kwang-Ju and Che-Ju cities on 5th to 17th February 1996. Data were analyzed using statistical package SAS. The findings were as follows : 1. The mean scores of the degree of perceived powerlessness of the subjects were 58.90 out of 85. The elderly people in Kwang-Ju city perceived more powerlessness than elderly people of Che-Ju city. 2. The factors which influence the powerlessness of the elderly were age, gender, education level, living standard, spouse, former and present job, health condition, family support, social and recreational activities. From the results of this study, to alleviate the powerlessness of the elderly, with the efforts of health maintenance and promotion various community based social activities and support system should be developed for the elderly.

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인간관계와 의사소통 교과목의 효과 측정 (The Effect of Interpersonal Relationships and Communication Curriculum)

  • 현미열;박은옥
    • 한국간호교육학회지
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    • 제14권1호
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    • pp.5-11
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    • 2008
  • Purpose: The purpose of this study was to identify the effects of interpersonal relationships and communication curriculum on interpersonal relations and self-esteem. Method: This study employed a two-group pre-post test study design. Data was collected from 70 subjects from April to June, 2006 at C university in Jeju, Korea. Forty subjects were in the control group and 30 subjects were in the experimental group. A structured curriculum was conducted for the experimental group once a week for 12 weeks, but not for the control group. For both groups the scores of interpersonal relations and self-esteem were measured before and after the curriculum. Data was analysed by $X^2$-test, t-test, paired t-test and Pearson correlation with SPSS. Results: The scores of interpersonal relations and self-esteem significantly increased in the experimental group. There were significant positive correlations between interpersonal relationships and self-esteem. Conclusion: In light of these results, interpersonal relationships and communication curriculum have a positive effect on interpersonal relations and self-esteem. Therefore, this study can provide basic data and direction in developing and applying a curriculum in education.

웅성불임 기술을 이용한 침파리 구제에 관한 연구 -침파리의 인공대량 사육에 관하여(II)- (Study on Stable Fly Eradication by Sterile-Male Technique. (2) Mass Rearing of the Stable Fly, Stomoxys calcitrans L.)

  • 정규회;유준;권신한;박정덕;강태숙
    • 한국응용곤충학회지
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    • 제12권4호
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    • pp.153-155
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    • 1973
  • 1. 침파리의 동계사육 결과 평균온도 $23.7^{\circ}C$에서 유충기간 7일, 용기간 9.2일, 전산란기간 14.2일, 성충수명 23.3일이었다. 2. 5월부터 7월까지 사육온도 $25\pm1^{\circ}C$로 고정시켰을 때의 생육기간은 유충기간 8.0일, 용기간 5.3일, 전산란기간 11.7일, 성충수명 30.1일 이었다. 3. 용 개체중량은 5월-7월의 $25\pm1^{\circ}C$에서 13.3mg으로서 현저한 증가를 볼 수 있었다. 4. 전산란 기간중의 성충사망율은 습도 조절(R. H.)에 따라서 큰 차이를 보여주었으며 누대사육을위해서는 $55-65\%$의 R.H.를 유지할 필요가 있을 것으로 본다. 5. 성충의 산란율은 산란 시작후 제8-10일에 제일 높다.

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Preparation of Epoxy/Organoclay Nanocomposites for Electrical Insulating Material Using an Ultrasonicator

  • Park, Jae-Jun;Park, Young-Bum;Lee, Jae-Young
    • Transactions on Electrical and Electronic Materials
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    • 제12권3호
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    • pp.93-97
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    • 2011
  • In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a 0.35 ${\mu}M$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and 1.5 ${\mu}M$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($I_{SUB}$), drain to source leakage current ($I_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

"제민요술"에 수록된 식품조리가공법 연구보고(6) -병.종.열.자명.예.로- (A study on the cooking and processing methods presented in CHE MIN YO SUL)

  • 윤서석;윤숙경;조후종;이효지;안명수;안숙자;서혜경;윤덕인;임희수
    • 한국식품조리과학회지
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    • 제7권1호
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    • pp.81-85
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    • 1991
  • This study was carried out to understand and analyze the cooking and processing methods presented in CHE MIN YO SUL (chapter 82~86). The result from the study are as follows; 1. Byung was made from dough of wheat flour, glutinous rice flour, small green peas flour an rice of millet etc. by steaming, roasting, deep fat frying or sauted, or it had eaten Byung which was made from egg or seagull's egg without cereal was simillar to Korea's fried egg cake. 2. Jong and Youl were steamed product made from mixture of millet and rice which were wrapped with leaf of Julpool or bamboo's leaf. It's shape was simillar to Korea's Song-Pyun but different from materials and cooking method. 3. Jamyong's cooking method was boild the mixture of white rice soup, Myong-Jup, and salt. and then pour the rised Bal. 4. Ye and Lo were boiling product made from new oat and appricot seed flour. It was simillar to sweet drink made from rice, and put them in the jar for storage.

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물려받은 학령기 아동의복의 인식에 관한 연구 -가족구성 서열에 의한 연령층 비교- (A Study of the Relationship between Hand-me-down Clothing and Clothing Behaviors of Elementary School Children.)

  • 정삼호
    • 한국의류학회지
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    • 제5권1호
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    • pp.1-7
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    • 1981
  • The purpose of this study was to investigate the attitudes of handed-me-down clothing in the Che-ju elementary school children. Measures of attitudes toward handed-me-down clothing consisted of: 1) attitudes of receiver's 2) feeling of receive.'s 3) behaviors 4) possession 5) frequency of wearing handed-me-down clothing. Two aspects of clothing behaviors were slightly modified to assess conformity?individuality, satisfaction in clothing. The sample consisted of 565 students in Che-ju elementary school children, Korea. The data, collected by means of a self-administered questionaire, were analysed by Chi-Square ($X^2$) and Correlation(R). The results indicated that: 1. Handed-me-down clothing was not significantly different between elder brothers (sisters) and child. 2. Most of the children wanted to wear comfort, good style, fit and neat in handed-me-down clothing. 3. Most of the children were satisfied with their handed-me-down clothing and tended not to be aware of the source in clothing. 4. Most of the children had higher interest of individuality and satisfaction in clothing behaviors.

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동충하초 엑스의 고콜레스테롤혈증 대사효소 활성 변동에 관한 효과 (Studies of the Cordyceps militaris Extract Administration on the Metabolic Enzyme Activities in Hypercholesterolemia)

  • 김한수;김민아;장성호;강진순;이원기;류재용
    • 한국환경과학회지
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    • 제21권10호
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    • pp.1213-1219
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    • 2012
  • The objective of this study was to investigate the effects of the feeding Cordyceps militaris extract on the improvement of the free fatty acid, lipid peroxide, creatinine and enzyme (creatine phosphokinase; CPK, lactate dehydrogenase; LDH, alkaline phosphatase; ALP, lecithin cholesterol acyltransferase; LCAT) activities in the sera of dietary hypercholesterolemic rats (SD strain, male) fed the experimental diets for 5 weeks. Concentrations of free fatty acid, lipid peroxide and CPK, LDH, ALP activities in sera were fairly reduced in the Cordyceps militaris extract administration group (CHE) than in the hypercholesterolemic diet group (CHD). However, no significance was found in the effect of an creatinine concentration among the groups. The LCAT activity in serum was increased in the Cordyceps militaris extract administration (CHE) than in the hypercholesterolemic diet group (CHD). From these results, Cordyceps militaris extracts were effective on the improvement of the lipid components and metabolic enzyme activities in sera of dietary hypercholesterolemic rats.

맨틀형 축열조의 열전달 성능 및 특성에 관한 실험적 연구 (An Experimental Study on the heat transfer characteristics and performance of storage tanks with mantle heat exchanger)

  • 강용혁;곽희열;윤환기;유창균;윤현식;천원기
    • 한국태양에너지학회 논문집
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    • 제21권1호
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    • pp.61-69
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    • 2001
  • The heat transfer characteristics of horizontal and vertical mantle heat storage tanks are studied in order to replace the tank-coil heat exchanger for application in thermosyphon solar water heaters. In this study, 5 mantle storage tanks with different geometric shape are manufactured into stainless steel and each tank is tested. For the test, The inlet flow rate of the heat transfer fluid is maintained 1.2 lpm consistently. The heat transfer fluid temperature through the mantle is $70{\pm}1^{\circ}C$. The temperatures of 26 points included the ambient temperature are measured at every one minute. The measured data are used to calculate the overall heat transfer coefficient(UA) using the LMTD(Log Mean Temperature Difference) method and it is used on the analysis of the heat transfer characteristics to search for optimum arrangement.

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Device Optimization of N-Channel MOSFETs with Lateral Asymmetric Channel Doping Profiles

  • Baek, Ki-Ju;Kim, Jun-Kyu;Kim, Yeong-Seuk;Na, Kee-Yeol
    • Transactions on Electrical and Electronic Materials
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    • 제11권1호
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    • pp.15-19
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    • 2010
  • In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a $0.35\;{\mu}m$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and $1.5\;{\mu}m$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($i_{SUB}$), drain to source leakage current ($i_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.