• Title/Summary/Keyword: heat-cold test

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Fabrication and Characteristic Test of Conduction-Cooled Brass Current Leads for a 22.9kV/630A Resistive Superconducting Fault Current Limiter System (22.9kV/630A 저항형 초전도 한류기용 전도-냉각 황동 전류인입선 제작 및 특성 실험)

  • Song, J.B.;Kim, J.H.;Kwon, N.Y.;Kim, Y.W.;Kim, H.M.;Sim, J.;Lee, B.W.;Kim, H.R.;Hyun, O.B.;Lee, H.G.
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.3
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    • pp.46-51
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    • 2007
  • The 22.9kV/630A superconducting fault current limiter (SFCL) is developed by the KEPRI-LSIS collaboration group. This resistive SFCL uses three pairs of conduction-cooled current leads. When the SFCL system is in the fault mode. the current flows 20 times more than the steady state. Therefore. it is important that the current lead is designed to have the thermal stability in order to minimize the heat input of the cold-end. This paper presents the design and performance results of a pair of conduction-cooled brass current leads considering both cases that the SFCL system operates at the steady state and the fault current.

A Study on the Analysis of Fire Mechanisms in Electronic Products due to Failure and Malfunction of Thermostats Through Fire Cases and Reproduction Experiments (화재사례 및 재현실험을 통한 온도조절장치 고장 및 오동작으로 인한 전자제품 화재 메커니즘 분석)

  • Jeong-il Lee;Jong-Hwa Im
    • Journal of the Korea Safety Management & Science
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    • v.26 no.1
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    • pp.31-38
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    • 2024
  • In this paper, as there are many cases of fires occurring due to the failure or inoperability of the thermostat of electronic products, the purpose is to test and analyze the risks and probabilities through fire cases and reproduction experiments, and suggest countermeasures. Among electronic products, water purifiers are composed of a refrigerant system with a compressor to make cold water, a heating device to make hot water, and an electric device used as an energy source. Due to the nature of the water purifier manufacturing, these devices are subject to a lot of moisture and dust. etc. exist in large quantities and use electrical energy, so there is a possibility of fire due to short circuit in the wire, electrical abnormal overheating (tracking phenomenon) in the thermostat, electronic board, starting relay, etc., and overheating of the heating device (Band Heater). there is. Therefore, in order to prevent fires from these devices, a system to remove foreign substances inside the water purifier is necessary, the use of heat-resistant (fire-resistant) wires for electrical devices is essential, and the use of non-combustible materials (semi-combustible materials) for each part is necessary to prevent fire. The risk must be eliminated through prevention and combustion expansion prevention devices.

Comparative Study of Non-Smoke Group and Smoke Group by Diagnosis System of Oriental Medicine (흡연군과 비흡연군의 폐활량과 한방변증 비교분석)

  • Park, Sung-Jun;Kim, Jin-Young;Shin, Woo-Jin;Park, Dong-Il
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.2
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    • pp.505-511
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    • 2009
  • The purpose of this study is to evaluate the difference about pathogenesis of smoker and non-smoker. Author used DSOM to investigate oriental pathogenesis. Smoke group is consisted of people who have history of smoke, and they don't have history of lung disease(Athma, tuberculosis, COPD, suchlike). Non-smoke group is consisted of people who have no history of smoke and they also don't have history of lung disease. Author carried out each group's PFT(Pulmonary Function Test) by AST(American Thoracic Society) method. DSOM was used for pathogenesis investigation of two groups. There was significant difference between smoke group and non-smoke group in FVC (p<0.05), and In non-smoke group, there was significant difference between male and famale in FVC, FVC%, FEV1, FEV1%. There was significant difference between smoke group and non-smoke group in Heat(熱), Cold(寒)(p<0.05). In Male grouop there was significant difference between smoker and non-smoker in deficiency of Deficiency of Yin(陰虛), Heat(熱). In non-smoke group comparison of sex, there was significant difference between male and female in Deficiency of blood(血虛), dampness(濕)(p<0.05). This result showed that the difference of pathogenesis between smoke group and non-smoke group.

Effect of Grain Size and Predeformation on Shape Memory Ability and Transformation Temperature in Iron Base Fe-Mn-Si System Shape Memory Alloy (다결정질 Fe-Mn-Si계 형상기억합금의 형상기억합금과 변태점에 미치는 결정입도와 이전가공의 영향)

  • Choi, Chong Sool;Kim, Hyun Woo;Jin, Won;Shon, In Jin;Baek, Seung Han
    • Journal of the Korean Society for Heat Treatment
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    • v.3 no.1
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    • pp.34-41
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    • 1990
  • Effects of grain size and cold rolling degree on shape memory ability and transformation temperature were studied in Fe-35% Mn-6% Si shape memory alloy. Md point of the alloy was determined by variation of yield stress with test temperature. The Md point measured in this way was linearly increased with increasing grain size. Shape memory ability of the alloy was decreased with increasing grain size, showing a minimum value at around $63{\mu}m$, and then increased with increasing grain size. From this result, it was concluded that the shape memory ability in the grain size smaller than a critical value is controlled by amount of retained ${\gamma}$ and prior ${\varepsilon}$ phase, but that the shape memory ability in the grain size greater than the critical value is mainly dominated by grain boundary area in unit volume of parent phase. The shape memory ability was decreased with increasing deformation degree. This was because the ${\gamma}$ content being available for the formation of ${\varepsilon}$ martensite during bending was decreased with increasing deformation degree.

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Developing a Multi-Functional Smart Down Jacket Utilizing Solar Light and Evaluating the Thermal Properties of the Prototype (태양광을 활용한 스마트 다운재킷 개발 및 보온성능 평가)

  • Yi, Kyonghwa;Kim, Keumwha
    • Journal of Fashion Business
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    • v.19 no.4
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    • pp.92-108
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    • 2015
  • This study aimed at developing a down jacket prototype that utilized sunlight as an alternative energy source with no air pollution. The jacket is filled with flexible solar panels and has a heat-generating function and LED function. In this study, three smart down jacket prototypes were developed, and the jacket's capabilities were demonstrated through the thermal effect on the performance test. The typical output voltage of the flexible solar panels was 6.4V. By connecting the 2 solar cell modules in series, the final output voltage was 12.8V. A battery charge regulator module was used the KA 7809 (TO-220) of 9V. Three heating pads were to be inserted into the belly of the jacket as direct thermal heating elements, and the LED module was configured, separated by a flash and an indicator. The smart down jacket was designed to prevent damage to the down pack without the individual devices' interfering with the human body's motion. Because this study provides insulation from extreme cold with a purpose, the jacket was tested for heat insulation properties of non-heating, heating on the back, heating on the abdomen, and heating on both the back and abdomen in a sitting posture in a static state. Thermal property analysis results from examining the average skin temperature, core temperature, and the temperature and humidity within clothing showed, that placing a heating element in one place was more effective than distributing the heating elements in different locations. Heating on the back was the most effective for maintaining optimal skin temperature, core temperature, and humidity, whereas heating on the abdomen was not effective for maintaining optimal skin temperature, core temperature, or humidity within clothing because of the gap between the jacket and the body.

The Study on the Physiological Response in Wearing Sportswear in Two Different Environments

  • Kwon, Oh Kyung;Kim, Jin-A
    • Fashion & Textile Research Journal
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    • v.2 no.5
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    • pp.416-422
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    • 2000
  • In this study, to find out the physiological reaction of the human body and the sensation of comfort when people are wearing sportswear which is made of waterproof breathable fabrics under general environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec) and rainy environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec, rainfall : 250 1/hr), we made an experiment with sportswear in an artificial climate chamber and studied the thermal physiological response and subjective sensation. Mean skin temperature of the subjects was low and had a big range of fluctuation in rainy environmental conditions of two condition. Temperature started to increase at the beginning of the exercise, reached the maximum at the 2nd level of the exercise and then started to decline. Rectal temperature showed a slighter increase and bigger range of fluctuation in general conditions than in rainy conditions. Except clothing micro climate in rainy conditions, temperature and humidity and their range of fluctuation around back were higher than those around chest. Humidity was high and had wide range of fluctuation in general conditions. Heart rate was 4.4 beats/min higher in general conditions. In subjective test on rainy conditions, the feeling of discomfort increased due to the raindrops fallen on the skin. Unlike that in general conditions, cold sensation increased and humidity sensation reached to the peak after the exercise. In wearing sportswear made of shape memory breathable waterproof fabric, controlling function over a small amount of heat and water was distinctive while it turned out to be not so comfortable over a large amount of heat and water. Through this, the limitation of shape memory breathable waterproof fabric was recognised.

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THE EFFECT OF PROCESSING METHOD AND SURFACE DESIGN ON THE TRANSVERSE STRENGTH OF REPAIRED DENTURE BASE RESIN (온성방법과 단면형태가 수종의 의치상 수리레진의 결합강도에 미치는 영향)

  • Kim, Kang-Nam;Bae, Tae-Sung;Han, Jung-Suk
    • The Journal of Korean Academy of Prosthodontics
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    • v.34 no.4
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    • pp.665-674
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    • 1996
  • This study was designed to evaluate the effect of processing method and surface design on the transverse strength of repaired denture base resin. Three heat-cured denture base resins(Vertex, Lucitone, Lang), one cold-cured resin(Lang), and one light-cured resin(Dentacolor gingiva material) were used for repair purpose. The specimens for 3-point flexure test were fabricated by five processing methods such as self-curing, pressure pot, boiling water, processing, and light curing. Finally to evaluate the effect of surface designs for repaired resin, three surface designs(butt, bevel, inverse bevel) were tested. Within the limit of this study, following conclusions were drawn. 1. Lucitone denture base material showed highest flexural strength of $131.37{\pm}2.15MPa$, and there were significant differences in stength between Lucitone and other resins. 2. Between two different self curing methods, self curing repair resin, Lang, cured by pressure pot method showed highest flexural strength, $58.49{\pm}4.89MPa$. 3. Among the heat cured repair resins, maximum transverse strength value of $88.69{\pm}16.60MPa$ was recorded in Lucitone group cured by processing method. 4. Inverse bevel joint design showed significantly higher bond strength than butt joint group, Maximum bond strength was $59.36{\pm}1.33MPa$ in inverse bevel joint design group.

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Flame Retardance and Thermal Resistance of CPE Rubber Compound Containing a Phosphoric Ester Flame Retardant BDPDH (인산 에스테르게 난연제 BDPDH를 첨가한 CPE 고무재료의 난연성 및 내열성)

  • Park, Hyun-Ho;Lee, Chang-Seop
    • Elastomers and Composites
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    • v.38 no.1
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    • pp.72-80
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    • 2003
  • Phosphoric ester compound was employed as thermal resistant and flame retardant for chlorinated polyethylene(CPE) rubber material which is used to prepare automotive oil cooler hose. Cure characteristics, physical properties, thermal resistance, and flame retardation of CPE rubber compounds were investigated. CPE rubber which has excellent properties such as cold resistance and chemical corrosion resistance, and is inexpensive in price than existing ethyleneacrylate rubber(EAR) was used to prepare a rubber compound useful for hose. A non-halogen flame retarding agent N,N'-bis- (diphenylphosphoro) diaminohexane(BDPDH), which is condensed phosphoric ester, was synthesized and it was mixed to CPE rubber material with the range of $0{\sim}30 phr$. From the test results, rheological properties, heat resistance, and flame retardance of CPE rubber compounds were found out to be much increased. The optimum content of BDPDH to rubber which gives maximum effect on thermal resistance and flame retardation, within the range of tolerable specification for rubber materials, was determined to be 20 phr.

Developing a Model for Estimating Leaf Temperature of Cnidium officinale Makino Based on Black Globe Temperature (흑구온도를 이용한 천궁 엽온 예측 모델 개발)

  • Seo, Young Jin;Nam, Hyo Hoon;Jang, Won Cheol;Lee, Bu Yong
    • Korean Journal of Medicinal Crop Science
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    • v.26 no.6
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    • pp.447-454
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    • 2018
  • Background: The leaf temperature ($T_{LEAF}$) is one of the most important physical parameters governing water and carbon flux, including evapotranspiration, photosynthesis and respiration. Cnidium officinale is one of the important folk medicines for counteracting a variety of diseases, and is particularly used as a traditional medicinal crop in the treatment of female genital inflammatory diseases. In this study, we developed a model to estimate $T_{Leaf}$ of Cnidium officinale Makino based on black globe temperature ($T_{BGT}$). Methods and Results: This study was performed from April to July 2018 in field characterized by a valley and alluvial fan topography. Databases of $T_{LEAF}$ were curated by infrared thermometry, along with meteorological instruments, including a thermometer, a pyranometer, and an anemometer. Linear regression analysis and Student's t-test were performed to evaluate the performance of the model and significance of the parameters. The correlation coefficient between observed $T_{LEAF}$ and calculated $T_{BGT}$ obtained using an equation, developed to predict $T_{LEAF}$ based on $T_{BGT}$ was very high ($r^2=0.9500$, p < 0.0001). There was a positive relationship between $T_{BGT}$ and solar radiation ($r^2=0.8556$, p < 0.0001), but a negative relationship between $T_{BGT}$ and wind speed ($r^2=0.9707$, p < 0.0001). These results imply that heat exchange in leaves seems to be mainly controlled by solar radiation and wind speed. The correlation coefficient between actual and estimated $T_{BGT}$ was 0.9710 (p < 0.0001). Conclusions: The developed model can be used to accurately estimate the $T_{Leaf}$ of Cnidium officinale Makino and has the potential to become a practical alternative to assessing cold and heat stress.

Analysis of Pathomechanisms of Dysmenorrhea by Diagnosis System of Oriental Medicine Pattern Identification Instrument (DSOM변증도구에 의한 월경통의 주요 병기인자 분석)

  • Chi, Gyoo Yong;Lee, In Seon;Kim, Kyu Kon;Jeon, Soo Hyung;Kim, Jong Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.4
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    • pp.274-278
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    • 2016
  • In order to analyze the pathomechanisms of dysmenorrhea and efficiency of DSOM(diagnosis system of oriental medicine), clinical test was performed for 541 childbearing women having menstrual pain in P metropolitan city. The experimental group was composed of subjects who experience discomfort in daily life or interpersonal activities caused by menstrual pain with scores of 4 or above on the measurement of menstrual pain (MMP). The control group was composed of subjects reporting little or no discomfort with scores of 3 or below on the MMP. The menstrual period measurements were taken within 2-3 days following the first day of menstruation, when menstrual pain is at its peak. While non-menstrual period measurement were within 7-10 days after the last day of menstruation. The dampness pathomechanism was yielded most frequently in both groups, and then heart、heat、blood deficiency、cold、qi deficiency、phlegm、qi congestion、blood stasis in order. And the significant differences were in the pathomechanisms of blood deficiency、blood stasis、qi congestion、five viscera、phlegm and cold between the two groups. This means that general pathomechanisms of childbearing women in twenties mainly are dampness and heat, especially the experimental group has mostly disharmony of six qi and/but then move to insufficiency and stagnation of qi and blood and then to visceral disease pattern having statistically significant difference. Moreover in the two times of investigation, the output of pathomechanisms in each group has similar pattern in the same group. Therefore it can be concluded that the results of pathomechanisms by DSOM were in accordance with existing pattern classifications of dysmenorrhea in general and the DSOM showed reproducibility and stability in the data processing of questionnaires.