• 제목/요약/키워드: keeping temperature

검색결과 368건 처리시간 0.028초

평판형 액체식 PVT 모듈의 성능 실험 분석 (An Experimental Study of PV/Thermal Combined Collector Module)

  • 강준구;김진희;김준태
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.780-785
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    • 2009
  • The photovoltaic/thermal collectors (PV/T collectors) combine the solar thermal collector and photovoltaic modules. They can produce thermal energy in the form of hot air or hot water, and converts solar radiation into electricity. The collecctors can improve the electrical performance of PV modules as the heat from the PV module carried away by the thermal part of the system keeping temperatures lower. The basic water cooled PVT collector has metallic water pipes attached to the back of a PV collector. There are main parameters affecting the performance (electrical and thermal) of PVT collectors. This paper analyzed the experimental performance of glazed water PVT module, considering the parameters of solar radiation, inlet water temperature and ambient temperature. It found that solar radiation is the dominant factor for the electrical performance of the collector, and for the thermal performance the inlet water temperature and ambient temperature appeared to be more related.

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감소된 하드웨어 구조를 가지는 고성능 색조 변환 시스템의 설계 및 구현 (Design and Implementation of High Performance System with Reduced Hardware Architecture to Convert a Color Tone)

  • 문오학;이호남;이봉근;강봉순;홍창희
    • 융합신호처리학회논문지
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    • 제2권4호
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    • pp.1-8
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    • 2001
  • 본 논문에서는 감소된 하드웨어 구조를 가지는 고성능 색조 변환 시스템을 제안한다. 입력 영상의 색조를 변환하기 위해서는 입력 영상의 색 온도를 구하는 것이 필요로 한다[1]. 색 온도를 구하기 위해서는 2-D 조명 색조 좌표에 의한 색 온도 계산 알고리즘을 필요로 한다. 그러나 20D 조명 색도 좌표 계산에 의해 색 온도 알고리즘을 채택하면 하드웨어 부담이 매우 큰 문제점이 있다. 그러므로 본 논문에서는 2-D 색 온도 알고리즘의 성능을 유지하면서, 하드웨어 복잡도를 감소시킬 수 있는 1-D 조명 색도 좌표에 의해 색 온도 계산 방법을 제안한다. 본 논문에서는 제안한 방법은 Xilinx Virtex FPGA XCV 2000E-6BG560을 이용하여 65MHz의 고속 동작과 1344*806의 고해상도를 가지는 fLCD-TV 시스템에서 검증하였다.

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남녀 대학생의 겨울철 실내 쾌적온도 및 적정온도 (Preferred and Suggested Winter Indoor Temperatures of College Students)

  • 심현섭;정운선
    • 한국지역사회생활과학회지
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    • 제22권3호
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    • pp.485-491
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    • 2011
  • This study was to present the preferred and the suggested indoor temperature of college students in winter based on their body composition. A total of 14 subjects(6 males and 8 females) participated in this study. They sat in a climatic chamber controlled at $24^{\circ}C$ wearing experimental garments(0.7clo). The air temperature decreased $1^{\circ}C$ every 15 minutes until it reached $19^{\circ}C$. After the stepwise temperature change, subjects were asked to select a comfortable air temperature by dialing the temperature control switch inside the chamber. The preferred temperature was determined when subjects did not change the air temperature for 10 minutes. The measurements were oxygen consumption, rectal temperature, skin temperature, and subjective sensation. Main results are as follows. In a mild cold condition, females demonstrated lower oxygen consumption and mean skin temperature than males while keeping a constant rectal temperature. Females increased rectal temperature and decreased mean skin temperature greater than males from $24^{\circ}C$ to $19^{\circ}C$. Males showed larger oxygen consumption increase than females. It appears that the thermo-physiological responses in a mild cold condition might be different between males and females. The preferred winter indoor temperature was $22.3^{\circ}C$ for males and $23.4^{\circ}C$ for females, and the suggested temperature was $21^{\circ}C$ for males and $23^{\circ}C$ for females.

여름방학 중 결식아동 도시락 제공 기관의 운영관리 실태 (Current Status of Meal Box Service Management for Children from Low-income Families During Summer Vacation)

  • 윤보람;윤지현;심재은;권수연
    • 대한지역사회영양학회지
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    • 제14권2호
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    • pp.206-215
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    • 2009
  • The purpose of this study was to investigate the current status of foodservice management in organizations delivering meal boxes for low-income children during summer vacation. A survey was conducted with persons in charge of meal box production and service of these organizations via mail. Out of 114 questionnaires distributed nationwide, 100 were analyzed(87.8% analysis rate). Over half(53%) of the organizations delivered meal boxes consisting of rice and side dishes while the rest delivered side dishes only. About 81% of the organizations received KRW 3,000 per meal from their local governments and the rest received KRW 3,500. Only 28% of organizations had employed a dietitian. Over one-third(38%) of the respondents were unaware of the official nutritional standard of the foodservice program for low-income children during vacation. Most of the organizations(94%) had menu planned in advance. The average percentage of food cost was 84.1%. Over 40% of the organizations did not keep food samples for sanitation test(43%) and did not take any measures for keeping food temperature during delivery(45%). The organizations delivering rice and side dishes were more likely to be located in cities rather than rural areas and received higher reimbursement rate. The organizations receiving reimbursement of KRW 3,500 or hiring a dietitian were more likely to use standardized recipes, keep food samples for sanitation test, or take measures for keeping food temperature during delivery compared to the counterparts. Respondents reported that increasing reimbursement rate was the most necessary for improving the quality of meal box. This study results showed that the meal box delivery service for low-income children was not properly managed during the vacation, with regards to menu planning and food production. It is recommended that reimbursement rate for meal boxes should be adjusted depending on meal box types and local conditions.

노인 친화적 감성용 욕조 대안에 대한 노인 소비자의 요구 및 평가 (A Survey on the Aged Consumers' Needs for an Elderly Friendly and Sensitive Bathtub Alternative)

  • 최병숙;권대규
    • 한국주거학회논문집
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    • 제24권6호
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    • pp.41-49
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    • 2013
  • This study finds out the aged consumers' needs on the developing elderly friendly and sensitive bathtub. This bathtub focuses on enhancement of multi-senses and enhancement of health, safety & convenience during bath. The enhancing multi-senses would have four functions; therapy with color and aroma, the massage with micro water bubbles, the visual and auditory with TV & cinema, and the auditory with music and radio. Also, enhancing others of bathtub would have seven functions; emergency bell, blood-pressure check system for health condition, water temperature indicator, keeping water warm, reading a book in that, and controlling of house entrance door and a getting the phone during bath. The aged consumers' needs find throughout a questionnaire survey, and 497 data was analyzed. The main results are as follow. They consider a full bath behavior as a healthcare. They have an intention to purchase or use the elderly and friendly bathtub, and they prefer using it in common facilities to using it at home. They highly need health related function of bathtub, which are massage (64.4%), blood-pressure check system (55.1%) and aroma therapy (45.7%). The emergency bell (67.0%), keeping water warm (62.2%), and water temperature indicator (49.7%), related to safety & information function of bathtub, are needed. Also, they think tolerance for error and low physical effort in bathtub design alternative, opening door and inside sitting support, to be important.

세포외 5-Fluorocytosine Deaminase의 특성 (Properties of an Extracellular 5-Fluorocytosine Deaminase)

  • 이인;전홍기;윤용균
    • 한국미생물·생명공학회지
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    • 제20권2호
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    • pp.150-155
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    • 1992
  • 토양 분리 균주로부터 얻은 배양액을 20-80 황산암모늄으로 분획한 후 세포의 cytosine deaminase의 성질을 검토하였다. 이 효소는 cytosine과 5-fluorocytosine(5-FC)에 기질 특이성을 가짐으로서 각각 uracil과 5-fluorouracil(5-FU)로 전환을 촉매하였다. 효소안정성에 대한 온도와 보존기간은 tris-HC1 완충용액에서 검토한 결과 최적온도는 $50^{\circ}C$ 부근이하에서 90 이상의 잔존활성을, 보존시간은 4일정도에서 80 이상의 잔존활성을 유지하였다. 최대 pH 8.0과 $37^{\circ}C$의 온도에서 나타났다. 활성에 적당한 pH는 8.0~8.5였고, 온도는 37~$45^{\circ}C$의 범위였다.

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Responses of HSP Gene Expressions to Elevated Water Temperature in the Nile tilapia Oreochromis niloticus

  • Kwon, Joon-Yeong;Kim, Ju-Yeong
    • 한국발생생물학회지:발생과생식
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    • 제14권3호
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    • pp.179-184
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    • 2010
  • Water temperature influences on various key biological events in fish, but the internal pathway of the temperature effects are not well understood. Heat shock proteins (HSPs), known to respond in the level of cells to many environmental factors including temperature, could improve our understanding on the pathway. Some biological processes such as gonadal development and sex differentiation in the Nile tilapia Oreochromis niloticus is particularly sensitive to water temperature. In this study, we have investigated the expressions of HSP70 and HSP90 genes in young tilapia at an ordinary temperature ($28^{\circ}C$) and elevated water temperature ($36^{\circ}C$). The distribution of the expressions of HSP70 and HSP90 mRNA in this species were found to be almost ubiquitous, being detected in all tissues studied here (brain, gonad, liver and muscle), suggesting the house keeping functions of these genes. Heat shock by elevating temperature from $28^{\circ}C$ to $36^{\circ}C$ significantly increased the expression of HSP70 mRNA in the gonad, liver and muscle for several hours (P<0.05) (brain tissue was not examined for this). The increased level of HSP70 gene expression recovered to the level at control temperature ($28^{\circ}C$) when fish were kept continuously at high temperature ($36^{\circ}C$) for 24 hours. Contrary to this, expression of HSP90 mRNA did not show significant increase in the gonad and muscle by the same heat shock (P>0.05), except in the liver where the expression of HSP90 mRNA increased continuously for 24 hours at $36^{\circ}C$. The results obtained in this study suggest that response to temperature change in different tissue or organ may utilize different heat shock proteins, and that HSP70 may have some importance in temperature-sensitive gonadal event in the Nile tilapia.

수출딸기 '매향'의 신선도 유지를 위한 수확시간, 예냉 및 저장온도의 효과 (Effect of Harvest Time, Precooling, and Storage Temperature for Keeping the Freshness of 'Maehyang' Strawberry for Export)

  • 박지은;김혜민;황승재
    • 생물환경조절학회지
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    • 제21권4호
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    • pp.404-410
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    • 2012
  • 본 연구는 수출용 딸기 '매향' 품종을 09:00와 14:00에 각각 수확하여 $4^{\circ}C$ 예냉 처리 혹은 예냉 무처리 후 $4^{\circ}C$$8^{\circ}C$에 저장하면서 딸기의 품질변화와 상품성 유지 효과를 구명하기 위해 수행되었다. 2010년 5월 4일에 숙도 60%의 과실을 경상남도 진주지역 상업적 온실에서 수확하였다. 농가의 예냉기에서 3시간 동안 예냉한 딸기를 30분 만에 실험실로 수송하고, 즉시 저장고에 저장하였다. 예냉은 농가 현장에 설치되어 있는 간이 예냉기를 이용하였다. 과실은 PVC랩과 골판지상자에 포장 된 후 $4^{\circ}C$$8^{\circ}C$의 항온 저장고에 두어 실험하였다. 저장하는 동안 딸기의 무게변화, 경도, 색도, 당도, 잿빛곰팡이 발생률을 이틀 간격으로 2010년 5월 6일부터 5월 14일까지 조사하였다. 숙도가 진행됨에 따라 경도 및 당도가 감소하였다. Hunter 'L'과 'a' 값은 시간이 경과함에 따라 감소하였다. 또한 모든 온도처리에서 저장 기간이 경과함에 따라 무게의 변화가 감소하였다. 과실의 표피조직에 무름병의 발생 시작 후 잿빛곰팡이가 발생하였다. 잿빛곰팡이는 저장온도 $4^{\circ}C$ 처리구에서 보다는 $8^{\circ}C$ 처리구에서 가장 많이 발생하였다. 하지만 수확 시간과 예냉 유무에 따른 저장성의 차이는 나타나지 않았다. 본 연구는 $4^{\circ}C$ 예냉처리 후 $4^{\circ}C$에서 저장하였을 때 신선도가 가장 오래 유지되었다.

MCFC 배가스용 촉매연소기 연소특성에 관한 연구 (A Study on the Combustion Characteristics of MCFC Offgas Catalytic Combustors)

  • 이상민;이연화;안국영;박인욱
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.132.1-132.1
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    • 2010
  • Anode off-gas of high temperature fuel cells such as MCFC still contain combustible components such as hydrogen, carbon monoxide and hydrocarbon. Thus, it's very important to fully burn anode off-gas and use the generated heat in order to increase system efficiency. In the present study, catalytic combustors have been applied to high temperature MCFC system so that the combustion of anode-off gas can be boosted up. Since the performance of catalytic combustor directly depends on the combustion catalyst, this study has been focused on the experimental investigation on the combustion characteristics of multiple commercial catalysts having different structures and compositions. In order to determine the design conditions of the catalytic combustor, parameters such as inlet temperature, space velocity and excess air ratio have been varied and optimized for combustor design. Results show that $H_2$ in off-gas assists $CH_4$ combustion in a way that it decreases minimum inlet temperature limit and increases maximum space velocity while keeping high fuel conversion efficiency.

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VO2 온도센서를 이용한 전원차단 PCM 구성 (Built-in protection circuit module by using VO2 temperature sensors)

  • 송건화;최정범;손명우;유광수
    • 센서학회지
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    • 제18권1호
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    • pp.28-32
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    • 2009
  • Most portable mobile devices employ rechargeable lithium-ion batteries. This lithium-ion battery usually suffers from the possibility of explosion due to heat generation from surrounding atmosphere or internal deficiency during charging or at overuse. To solve these problems, most rechargeable batteries have a built-in protection circuit module (PCM). The resistance of a properly processed $VO_2$ critical temperature sensor (CTS) is changed dramatically at a critical temperature of around $68^{\circ}C$, which can replace some bi-metal, NTC, or PTC sensors embedded in PCM. Such $VO_2$ CTS consumes a very small current at the level of natural discharge. Experimental results showed that this CTS could be applied to a PCM as the PCM could protect the battery while keeping its power consumption at minimum.