• 제목/요약/키워드: Cold

검색결과 11,156건 처리시간 0.041초

BODY HEAT CONTENT, HEAT PRODUCTION AND RESPIRATION IN SHEEP EXPOSED TO INTERMITTENT COLD

  • Lee, S.R.;Sasaki, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제7권3호
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    • pp.357-362
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    • 1994
  • Five adult sheep were exposed to intermittent cold for 12 h (18:00-06:00) at an air temperature of $5{\pm}1^{\circ}C$ followed by 12 h (06:00-18:00) at $25{\pm}2^{\circ}C$ over a period of 8 days continuously. Carotid artery blood (Tc), mean skin (Ts) and mean body (Tb = 0.86 Tc + 0.14 Ts) temperatures, heat production rate (HP), respiratory evaporative heat loss, respiration rate (RR) and volume were measured before and after exposure. Tc during the 12 h cold period of intermittent cold exposure was similar to that during the corresponding period in the warm environment, while Tc in the $25^{\circ}C$ of intermittent cold was higher (p < 0.05) than that in the corresponding period in the warm environment. Ts during the cold period markedly decreased (p < 0.001) by about $9^{\circ}C$ when compared with that in the corresponding time period in the warm environment, while Ts during the $25^{\circ}C$ period of intermittent cold recovered to a similar level to that in the warm environment. Tb was lower (p < 0.001) during the cold period of intermittent cold, whereas a slight increase in Tb during the $25^{\circ}C$ period of intermittent cold was significant (p < 0.05) when compared with the value during the similar period in the warm environment. HP was greatly increased (p < 0.001) by cold exposure, followed by an immediate decrease during the first one hour of the 12 h warm period, reaching a similar level to that in the warm environment. A lower (p < 0.05) RR was observed during both the cold and $25^{\circ}C$ period of intermittent cold than during the corresponding periods in the warm environment. The results of the present investigation clearly show that the body temperature of sheep increased during a 12 h warm period following 12 h of exposure to cold. These results suggest that during a warm period of an intermittent cold exposure cycle, heat could be shored in the animal body.

전기자동차용 Cold Plate의 열전달 및 압력손실 특성 연구 (Heat Transfer and Pressure Drop Characteristics of the Cold Plate for an Electric Vehicle)

  • 함진기;이준엽;송석현
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1566-1571
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    • 2003
  • The cold plate used for a CEU(Control Electronics Unit) of an EV(Electric Vehicle) is extremely important since the dissipation of the heat generated from power devices like IGBT(Insulated Gate Bipolar Transistor) and diode has a significant effect on the performance as well as the durability of the CED. The cold plate consists of seven power devices, and coolant flows through the passage bonded to a groove of the cold plate. In order to find out heat transfer and pressure drop characteristics, series of numerical analyses for the cold plate with enhanced coolant passages were conducted. Based on results of the numerical analyses, an improved model of the cold plate has been proposed. The experiments under the various conditions have been conducted to compare the performance of the proposed cold plate to the present one. As a result of the numerical analyses together with the experiments, the ideal design of the cold plate could be offered.

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한수(寒嗽)의 원인(原因) 증상(症狀) 치료처방(治法處方)에 관(關)한 문헌적(文獻的) 고찰(考察) (The investigation of Literature about cause, Symptom, theory of treatment prescription of 'Han-So'( ) = cough caused by cold-evil)

  • 박동일;정승기;이형구
    • 대한한방내과학회지
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    • 제11권1호
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    • pp.157-164
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    • 1990
  • The results of the investigation of literature were summerized as follows ; 1. The factors of cough caused by cold-evil were revealed as the following order cold weather and drinking cold water, the disease caused by exoganous cold-evil and wind-evil, Lung affected by cold-evil, both spleen and lung avoided by cold-evil 2. The symptom of cough caused by cold-evil were appeared as follows. Tense pulse, Tense chest-voice hoarsness, intolerance to cold, fever anhidrosis fidgetiness nonthirst cough caused by cold-evil 3. The treatment of cough caused by cold-evil were showeding as follws Cleaning away cold-evil eliminating the pholegm, dispelling exogenous evils, making warm-heat 4. The prescription of 'Han So' were used frequently as the orders followed

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한열과 음성분석지표의 상관성 연구 (Correlation Analysis between Cold-Heat Score and Acoustic Analysis Index)

  • 양동훈;유승연;조신웅;박찬규;박영재;박영배
    • 대한한의진단학회지
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    • 제13권1호
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    • pp.72-80
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    • 2009
  • Objective: We performed this study to check relationship of Cold-Heat attribute analyzed quantitatively by questionnaire with acoustic analysis index. Method : We checked a questionnaire composed of 15 items about the contents of Cold-Heat and asked 83 subjects to answer in the form Likert-like 7-points score. And then, we extracted Cold-Heat attribute from heat score, cold score, heat index and cold index. we measured the acoustic analysis indexes of cardinal vowels by Dr. speech program. Afterward, the data were analyzed by correlation analysis. Results : All cardinal vowels is positive correlated with cold score, heat score and cold index. NNE of vowel /a/ is negative correlated with cold index. Shimmer and F0 tremor of vowel /e/ is negative correlated with cold index. Jitter of vower /u/ is positive correlated with Cold score.

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Characterization of transcription factor genes related to cold tolerance in Brassica napus

  • Sharma, Mayur Mukut Murlidhar;Ramekar, Rahul Vasudeo;Park, Nam-Il;Choi, Ik-Young;Choi, Seon-Kang;Park, Kyong-Cheul
    • Genomics & Informatics
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    • 제19권4호
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    • pp.45.1-45.8
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    • 2021
  • Brassica napus is the third most important oilseed crop in the world; however, in Korea, it is greatly affected by cold stress, limiting seed growth and production. Plants have developed specific stress responses that are generally divided into three categories: cold-stress signaling, transcriptional/post-transcriptional regulation, and stress-response mechanisms. Large numbers of functional and regulatory proteins are involved in these processes when triggered by cold stress. Here, our objective was to investigate the different genetic factors involved in the cold-stress responses of B. napus. Consequently, we treated the Korean B. napus cultivar Naehan at the 4-week stage in cold chambers under different conditions, and RNA and cDNA were obtained. An in silico analysis included 80 cold-responsive genes downloaded from the National Center for Biotechnology Information (NCBI) database. Expression levels were assessed by reverse transcription polymerase chain reaction, and 14 cold-triggered genes were identified under cold-stress conditions. The most significant genes encoded zinc-finger proteins (33.7%), followed by MYB transcription factors (7.5%). In the future, we will select genes appropriate for improving the cold tolerance of B. napus.

Identification and functional analysis of COLD-signaling-related genes in Panax ginseng

  • Jeongeui Hong;Hojin Ryu
    • Journal of Plant Biotechnology
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    • 제50권
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    • pp.225-231
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    • 2023
  • Cold stress is one of the most vulnerable environmental stresses that affect plant growth and crop yields. With the recent advancements in genetic approaches using Arabidopsis and other model systems, genes involved in cold-stress response have been identified and the key cold signaling factors have been characterized. Exposure to low-temperature stress triggers the activation of a set of genes known as cold regulatory (COR) genes. This activation process plays a crucial role in enhancing the resistance of plants to cold and freezing stress. The inducer of the C-repeatbinding factor (CBF) expression 1-CBF module (ICE1-CBF module) is a key cold signaling pathway regulator that enhances the expression of downstream COR genes; however, this signaling module in Panax ginseng remains elusive. Here, we identified cold-signaling-related genes, PgCBF1, PgCBF3, and PgICE1 and conducted functional genomic analysis with a heterologous system. We confirmed that the overexpression of cold- PgCBF3 in the cbf1/2/3 triple Arabidopsis mutant compensated for the cold stress-induced deficiency of COR15A and salt-stress tolerance. In addition, nuclearlocalized PgICE1 has evolutionarily conserved phosphorylation sites that are modulated by brassinsteroid insensitive 2 (PgBIN2) and sucrose non-fermenting 1 (SNF1)-related protein kinase 3 (PgSnRK3), with which it physically interacted in a yeast two-hybrid assay. Overall, our data reveal that the regulators identified in our study, PgICE1 and PgCBFs, are evolutionarily conserved in the P. ginseng genome and are functionally involved in cold and abiotic stress responses.

LNG 냉열이용 액체수소 제조공정의 예냉 및 Cold box의 성능 개선 연구 (Performance Improvement of Precooling Process and Cold Box in Hydrogen Liquefaction Process Using LNG Cold Energy)

  • 윤상국;윤나은
    • 한국가스학회지
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    • 제24권4호
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    • pp.56-61
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    • 2020
  • 수소의 액화에는 예냉 에너지, 상변화 에너지, 수소 변환열 제거 등 다량의 에너지가 요구되어진다. 본 논문의 목적은 예냉공정에 필요한 에너지로 LNG냉열로 액체질소를 제조하여 사용하는 LNG냉열 간접 이용 방식과, Cold box의 단열에 냉공기를 이용하는 새로운 에너지절약 공정을 제안하여 수소액화 수율을 향상시키고자 하였다. 분석 결과를 보면, LNG냉열 간접이용 방식은 에너지 절약과 함께 액체수소 플랜트의 안전성을 제공하는 장점을 갖는다. 새로운 Cold box 단열 방식은 외벽 철판 3mm/우레탄폼 20cm/공기 5cm/우레탄폼 20cm/설비의 구조일 때 현재 펄라이트 단열에 비교하여 열유입량이 약 35%~50%가 감소하게 된다. 또한 냉공기 보다 온도가 높은 설비는 냉각의 효과를 얻게 된다. 수소액화 플랜트의 공정에 본 결과를 적용한다면 액체 수율이 50% 내외로 크게 향상되는 효과를 제공하게 된다.

저온숙성 반죽이 바켓의 품질에 미치는 영향 (Influences of Cold Aged Dough on the Quality of Baguette)

  • 황성연;김영만;조대희
    • 한국식품영양학회지
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    • 제11권4호
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    • pp.369-374
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    • 1998
  • This study was conducted to investiagte influences of cold aged dough on the quality of bagutte. After 2 hours fementing, the dough was divided 2 parts and they were stored in the refrigirated adjusted 1∼-1$^{\circ}C$. The cold aging time was 24, 48 hours respectivley. After 2 hourse fermentation, the dough's pH was 5.45 and 24, 48 hours cold aged dough were 4.99, 4.81. During cold aging, the difference of pH was not significant. The main organic acids in the baguette were lactic acid, acetic acid and malic acid, Among these organic acids, the acetic acid was the largest quantity regardlessly in different fermentation and the cold aging acids, time. Right after baking, the enthalphy of all samples were almost same even thought in different cold aging time, but during different storage periods they showed the difference of retrogradation by the increase of the enthalphy. 24 hours cold aging baguette had the best taste, aroma and texture in bread's score sheet.

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SIMULATION OF STARTING PROCESS OF DIESEL ENGINE UNDER COLD CONDITIONS

  • Park, J.K.
    • International Journal of Automotive Technology
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    • 제8권3호
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    • pp.289-298
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    • 2007
  • A nonlinear dynamic simulation model from cranking to idle speed is developed to optimize the cold start process of a diesel engine. Physically-based first order nonlinear differential equations and some algebraic equations describing engine dynamics and starter motor dynamics are used to model the performance of cold starting process which is very complex and involves many components including the cold start aiding method. These equations are solved using numerical schemes to describe the starting process of a diesel engine and to study the effects of cold starting parameters. The validity of this model is examined by a cold start test at $-20^{\circ}C$. Using the developed model the effects of the important starting variables on the cold starting processes were investigated. This model can be served as a tool for designing computer aided control systems that improve cold start performance.

공기공급 시스템에 적용되는 Vortex Tube의 에너지 분리특성에 관한 연구(I) -저온출구 orifice의 직경변화에 의한 영향- (A Study for Energy Separation of Vortex Tube using Air Supply System (I) - the effect of diameter of cold end orifice -)

  • 이병화;추홍록;상희선
    • 한국안전학회지
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    • 제13권4호
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    • pp.9-18
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    • 1998
  • The vortex tube is a simple device for separating a compressed gaseous fluid stream into two flows of high and low temperature without any chemical reactions. Recently, vortex tube is widely used to local cooler of industrial equipments and air supply system. The phenomena of energy separation through the vortex tube was investigated experimentally. This study is focused on the effect of the diameter of cold end orifice diameter on the energy separation. The experiment was carried out with various cold end orifice diameter ratio from 0.22 to 0.78 for different input pressure and cold air flow ratio. The experimental results were indicated that there are an optimum diameter of cold end orifice for the best cooling performance. The maximum cold air temperature difference was appeared when the diameter ratio of the cold end orifice was 0.5. The maximum cooling capacity was obtained when the diameter ratio of the cold end orifice was 0.6 and cold air flow ratio was 0.7.

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