• Title/Summary/Keyword: Temperature condition

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Specification of Governing Factors for High Accurate Prediction of Welding Distortion (용접변형 고정도 예측을 위한 지배인자의 특정)

  • Lee, Jae-Yik;Chang, Kyong-Ho;Kim, You-Chul
    • Journal of Welding and Joining
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    • v.31 no.5
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    • pp.1-6
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    • 2013
  • In carrying out the elastic-plastic analysis, four conditions (equilibrium equation, constitutive equation, condition of compatibility and yield condition) should be satisfied. In welding, the temperature largely changed from a melting temperature to a room temperature. So, yield stress of materials largely changed, too. In particular, yield stress becomes about zero over $700^{\circ}C$. The analysis should be carried out under the condition that equivalent stress generated in temperature increment ${\Delta}T$ did not exceed yield stress of materials at high temperature over $700^{\circ}C$. It should be sufficiently recognized that the obtained results were not reliable if this condition was not satisfied.

Diagnostic of Cast Resin Using Active Infrared Thermal Testing Method (능동열시험법을 이용한 몰드변압기 진단)

  • Lim, Young-Bae;Jeong, Seung-Cheon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.481-484
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    • 2004
  • A form of measured temperature distribution to estimate condition of a electrical apparatus is a absolute reference for condition of the apparatus, time rate of transition, and difference between reference and currently temperature. Because passive thermography which has not injection of external thermal stimulation shows difference of temperature being on surface of a structure and temperature difference between the structure and back ground, the result could apply only to estimation or monitor for condition of terminal relaxation and overload related with temperature rising. However, a thermal flow in active thermography is differently generated by structure and condition of surface and subsurface. This paper presents the nondestructive testing using the properties and includes the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

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Effect of Heating Condition and Panax Ginseng on Body Temperature, Hematological Changes, and Immune Response in Rat (온열환경과 인삼(Panax Ginseng)이 Rat의 체온, 혈액학적 변화, 면역반응에 미치는 영향)

  • Yi, Seo-Ra;Lee, In-Hee;Kim, Min-Ji;Lew, Jae-Hwan
    • The Journal of Internal Korean Medicine
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    • v.35 no.1
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    • pp.59-69
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    • 2014
  • Objectives : This study was designed to test the effect of heating condition and Panax ginseng on body temperature, hematologicala changes, and immune response. Methods : The extract from Panax ginseng was made by the pharmacy department of Kyung Hee Oriental Medical Hospital. The animals were divided into four groups; control, room temperature Panax ginseng (G), $28^{\circ}C$ heating, and $28^{\circ}C$ heating Panax ginseng (heating G). Each group has 8 Sprague-Dawley rats. We measured body weight & temperature twice a week. After 2 weeks of experiment, serum lipid level, WBC, differential count, lymphocyte proliferation and immune cytokine concentration were measured. Results : 1. Simultaneous application of heating condition and Panax ginseng induced decreased body weight and increased body temperature. 2. Simultaneous application of heating condition and Panax ginseng induced decreased AST, ALT and BUN. 3. Simultaneous application of heating condition and Panax ginseng tended to decrease TNF-${\alpha}$ concentration, while application of room temperature and Panax ginseng tended to increase TNF-${\alpha}$ concentration. Conclusions : Simultaneous application of heating condition and Panax ginseng decreseas body weight, increases, body temperature and has a tendency to decrease TNF-${\alpha}$ concentration.

Clothing Microclimate and Subjective Sensations by Wearing Long Johns in Mildly Cold Air (겨울철 실내 온도에서 내복 착용에 따른 의복 기후와 주관적 감각)

  • Kim Myung-Ju;Lee Joo-Young
    • Journal of the Korean Home Economics Association
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    • v.42 no.10 s.200
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    • pp.91-104
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    • 2004
  • The purpose of this study was to examine the differences of clothing microclimates and the subjective sensations according to age, gender and clothing weight for $19^{\circ}C$ air temperature. This study was done to gain fundamental data related to saving heating energy and to improve health through wearing underwear (long johns) in lower indoor temperatures. The subjects were divided into four groups (6 young males, 5 young females, 6 old males, 6 old females), and our experiment consisted of three conditions; the first condition was wearing long underwear in $19^{\circ}C$ air (19CUW condition); the second condition was without wearing long underwear in $19^{\circ}C$ air (19C condition); and the third condition was without wearing underwear in $24^{\circ}C$ air (24C condition). The experiment showed that the clothing microclimate temperature and humidity was the lowest in the 19C condition and the highest in the 24C condition irrespective of age and gender. The clothing microclimate in the 19CUW condition was not significantly distinguishable from the other conditions. Clothing microclimate temperature and humidity when the subjects responded thermal comfort was $28\~34^{\circ}C$ and $15\~40\%$RH without any significant difference according to age and gender. For the thermal sensation, the 24C condition was regarded as the warmest environment by the four groups, and the next preference was the 19CUW condition (p<0.001). Young females and old males showed a tendency to feel colder than young males and old females. For the thermal sensation of hands and feet, the young groups felt the warmest in the 24C condition and the coolest in the 19 C condition (p<0.001). However, old males felt neutral for the foot thermal sensation without any significant difference between the three conditions. Old females felt neutral for both the hands and feet thermal sensations without any significant difference between the three conditions. Thermal preference was the highest in the 24C condition for the 4 groups. In the 19CUW condition, for the thermal preference, most young males and females responded 'No change'; on the other hand, mea of the old responded 'Warmer'(p<0.001). It was the 24C condition that the 4 subject groups felt the most thermally comfortable. In the 19CUW condition, over $80\%$ of responses of each group expressed satisfaction and in the 19C condition, over $80\%$ of responses of each group, except young females, expressed satisfaction. In conclusion, in view of the clothing microclimate and subjective sensations, the 24C condition was the condition that gave subjects the least cold stress and the best subjective preference. However, the 19C condition and the 19CUW condition was not such a cold stress as to give healthy subjects a thermal burden.

Environmental factors influencing on tuber germination in scirpus maritimus l. (매자기 槐莖의 發芽에 미치는 環境 要因들)

  • Yang, Hae-Kyeng;Kim, Ok-Kyung
    • The Korean Journal of Ecology
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    • v.15 no.2
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    • pp.127-135
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    • 1992
  • The effects of nacl concentration, temperatura, light and growth regulator(GA3, kinetin) on the tuber germination of s. maritimus were investigated. The germination percentage increased with decreasing nacl, showing salt tolerance through time, and with increasing temperature untile 20~30oC light / dark (12/12 hr) of optimal temperature. The multiplication of nacl and temperature on germination percentage and velocity, increased significantly in higher temperature than lower temperature in saline. The germination percentage showed high value in dark condition than in light condition which is the charracteristics of underground organ. and ga3 act as germination stimulator to overcome the inhibitory effect of nacl. The effect of ga3 showed significant differances on tubers of s. maritimus of germination but that of kinetin had a litter sffects on germination. Factors of nacl and temperature interacted significantly and the effects of nacl on germination percentage and velocity depended on temperature condition.

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The Resistivity Properties and Adhesive Strength of Cu Thin firms Fabricated by EBE Method (전자빔 증착법으로 제작한 Cu 박막의 부착력과 저항율 특성)

  • Paik, Sang-Bong;Shin, Joong-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.422-426
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    • 2003
  • Cu thin films of $6000{\AA}$ thickness were deposited by Electron Beam Evaporation(EBE) method on the glass. The resistivity properties and adhesion of Cu thin films were investigated by various annealing and substrate temperature. Cu thin films were annealed in the air and vacuum condition for 10 min after the deposition. The resistivity and adhesion(the force required to separate films from substrates) was measured by 4-point probe and scratch testing. The resistivity of non-annealing Cu thin films was distinguished more substrate temperature loot than substrate temperature R.T, $200^{\circ}C$. In the case of air condition annealing, as heating temperature was increased, the resistivity was decreased. In the case of vacuum condition annealing, the resistivity was increased at heating temperature $200^{\circ}C$. The best resistivity($1.72\;{\mu}{\Omega}{\cdot}cm$) of Cu thin films was obtained by the air condition heating temperature $200^{\circ}C$ at the substrate heating temperature $100^{\circ}C$. As a result of scratch testing, adhesion was increased by annealing. And maximum adhesion had 600 gf.

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Characterization of 3D Printed Re-entrant Strips Using Shape Memory Thermoplastic Polyurethane with Various Infill Density (채우기 밀도별 형상 기억 TPU 3D 프린팅 Re-entrant 스트립의 특성 분석)

  • Imjoo Jung;Sunhee Lee
    • Fashion & Textile Research Journal
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    • v.24 no.6
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    • pp.812-824
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    • 2022
  • This study proposes to develop a 3D printed re-entrant(RE) strip by shape memory thermoplastic polyurethane that can be deformed and recovered by thermal stimulation. The most suitable 3D printing infill density condition and temperature condition during shape recovery for mechanical behavior were confirmed. As the poisson's ratio indicated, the higher the recovery temperature, the closer the poisson's ratio to zero and the better the auxetic properties. After recovery testing for five minutes, it appeared that the shape recovery ratio was the highest at 70℃. The temperature range when the shape recovery ratio appeared to be more than 90% was a recovery temperature of more than 50℃ and 60℃ when deformed under a constant load of 100 gf and 300 gf, respectively. This indicated that further deformation occurred after maximum recovery when recovered at a temperature of 80℃, which is above the glass transition temperature range. As for REstrip by infill density, a shape recovery properties of 100% was superior than 50%. Additionally, as the re-entrant structure exhibited a shape recovery ratio of more than 90%, and exhibited auxetic properties. It was confirmed that the infill density condition of 100% and the temperature condition of 70℃ are suitable for REstrips for applying the actuator.

The effect of posture on the human thermoregulatory response (인체의 자세가 체온조절에 미치는 영향)

  • Shim, Hyun Sup;Choi, Jeong Wha
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.3
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    • pp.415-427
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    • 1993
  • The purpose of this study was to evaluate the thermoregulatory responses to postures under different environmental conditions and to obtain the basal information for standard clothing weight, indoor climates, and working condition. Two adult female (22.5yrs, 46kg) were participated in this study. The experimental conditions were divided into three groups ; 1) comfort($27{\pm}1^{\circ}C$, $60{\pm}10%$), 2) hot($34{\pm}1^{\circ}C$, $60{\pm}10%$), and 3) cold($21{\pm}1^{\circ}C$, $50{\pm}10%$) condition. The postures performed were as follows; standing, sitting on the chair, sitting on the floor, and supine on the floor. At each condition, subjective sensations, 12 points skin temperature, rectal temperature, total and local sweat rate, pulse rates, blood pressure, skin blood flow rate were measured. The results were as follows : 1. Rectal temperature was high significant among groups in order of supine, sitting on the floor, sitting on the chair, standing posture(p<0.01). 2. Skin temperature was high in part of contact with the surface of the floor or wall and the effect of posture was greater in peripheral temperature than torso temperature. Sitting on the chair and sitting on the floor posture showed higher peripheral temperature than standing and supine posture. And peripheral temperature was lower in supine posture than any other postures. 3. Total and local sweat rate were decreased in order of standing, sitting on the chair, sitting on the floor, supine posture. 4. Pulse rate and disastolic blood pressure were higher in standing posture than supine posture, and there was significant difference between two postures(p<0.001). 5. Blood flow rate of thigh was high in sitting on the chair and sitting on the floor posture and low in standing posture. Blood flow rate of leg was low in standing posture significantly(p<0.01). 6. In comfort and hot condition, temperature sensation and comfort sensation were higher in standing posture and lower in supine posture than any other postures. In cold condition, temperature sensation was lower and comfort sensation was higher in standing and supine posture than any other postures. And supine posture was appeared positive in hot condition and negative in cold condition. From this study, we confirmed the effects of posture on human thermoregulatory responses. Results indicate that even under same conditions and clothing weight, the insulation of clothing will be different to postures.

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Thermal and subjective responses by sun hats for farmer in a hot climatic chamber (서열 환경에서 농작업 모자 착용에 따른 체온 조절 및 주관적 반응)

  • 김명주;최정화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.5
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    • pp.713-722
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    • 2004
  • This study examined the effects of two kinds of functional sun hats through a head-manikin test and a climatic chamber trial for farm workers in summer. Experiment was composed of four conditions. The first condition was the condition without any hat (Control). The second was the condition with a sun hat on the market (Hat A). The third was the condition with a functional sun hat made of reflective fabric (Hat B). The last was the condition with a functional sun hat having a ventilating structure as well as reflective fabric (Hat C). For the subjects in the climatic chamber trials, 12 healthy males volunteered. Air temperature, relative humidity and globe temperature in the chamber was maintained at $33{\pm}0.5^{\circ}C,\;65{\pm}5%RH\;and\;39{\pm}1^{\circ}C\;(WBGT\;33^{\circ}C)$. Subjects did a simulated red pepper-work (50-min work and 10-min rest, twice repetition) for 120 min. As the result of head-manikin test, the surface temperature on middle of back-neck was the lowest in Hat B of four conditions and the surface temperature on top of head was the lowest in Hat C. As the result of climatic chamber trials, there were apparent differences between with (Hat A, Hat B, Hat C) and without a sun hat (Control). In rectal temperature ($T_{re}$), mean skin temperature ($\={T}_{sk}$), heart rate (HR), total sweat rate (TSR), The physiological heat strain was less in the condition with hats than in the condition without a sun hat. As the increasing rate in Tre, Hat B is the most effective hat for alleviation heat strain. As the subjective responses, Hat B was the most effective hat for thermal comfort even though the difference was not significant. Hat C was less effective than Hat B and the reason might be the increase of weight due to inserting the ventilating structure.

Changes of Behavioral and Physiological Responses Caused by Color Temperature

  • Lee, Young-Chang;Min, Yoon-Ki;Min, Byung-Chan;Kim, Boseong
    • Science of Emotion and Sensibility
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    • v.18 no.2
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    • pp.37-44
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    • 2015
  • LED lighting has an advantage of adjusting color temperature. This change of color temperature may derive change in behavioral and physiological responses of the visual perception for indoor environments. This research examined the changes of behavioral and physiological responses caused by the color temperature. The environment was configured that the indoor temperature was 20 degrees centigrade or less as the perceived uncomfortable environment in winter. Then, the comfortable sensation vote (CSV) and the results of 3-back working memory test were measured as behavioral responses. In addition, the Electrodermal Activity (EDA) and Electrocardiogram (ECG) were measured as the responses of autonomics nervous system (ANS) in the three conditions of color temperature (red: 3862K, white: 5052K, blue: 11,460K). As a result, behavioral responses were not significant by the condition of color temperature, but the tendency of occupants' physiological relaxation appeared in the blue color temperature condition compared with the white color temperature condition. Although the color temperature of LED lighting might be a small factor in terms of the characteristics of indoor environment, it suggests that the color temperature could have an impact on the physiological changes in the parasympathetic nervous system.