• Title/Summary/Keyword: thermal humidity

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NiO(Co0.25Mn0.75)2O3 and BaSrTiO3 thick films on alumina substrate as temperature and humidity ceramic multisensors

  • Oh, Young-Jei;Lee, Deuk-Yong
    • Journal of Sensor Science and Technology
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    • v.18 no.5
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    • pp.343-348
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    • 2009
  • $NiO{\cdot}(Co_{0.25}Mn_{0.75})_2O_3$(Mn-Ni-Co) and $Ba_{0.5}Sr_{0.5}TiO_3$(BST) thick films were screen printed on Pt patterned alumina substrate to investigate the effects of sintering temperature on humidity and temperature sensing properties of ceramic sensors. A raise in sintering temperature increased resistance and B constant of the Mn-Ni-Co temperature sensor. This may have derived from the synergic effects of the reduction in charge carriers caused by the substitution of Co for Mn as well as the formation of microcracks from the difference in thermal expansion coefficients. Dependence of resistance on humidity of the Mn-Ni-Co temperature sensor, however, was not found. BST films sintered at temperatures in the range of $1100^{\circ}C$ to $1150^{\circ}C$ showed excellent humidity sensing properties. The BST humidity sensor was faster in its response than the Mn-Ni-Co temperature sensor. The humidity sensor, however, proved to be unstable under various temperatures, suggesting a need for a temperature stabilizing device. In contrast, the Mn-Ni-Co temperature sensor was stable under humid conditions.

Thermal Properties on combination of Velvet and Lining (벨벳과 안감의 소재 조합에 따른 의복의 열저항에 관한 연구)

  • 계명대학교의류학과;이욱자;류덕환
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.1
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    • pp.3-13
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    • 1999
  • This study was performed for purpose of getting fundamental information requisite to wear velvet clothes that is more comfortable for the human body and also the environment. It was carried out in a human wearing test and thermal manikin test at the same time in a controlled-condition chamber. The experimental environment had a ambient temperature of 15$\pm$0.5$^{\circ}C$ with the relative humidity at 5$^{\circ}C$$\pm$5% and with air velocity at less that than 0.2m/sec. Velvet differ from common plain weaves in thermal properties because it's constructed in two parts one is ground part and the other part is pile part. In order to investigate the thermal resistance of velvet eight different combination of 4 velvet kinds and 2 lings kinds as experimental clothes. [(4 velvet kinds : Acetate cuprammoium Rayon Cotton Wool) (2 lining kinds : acetate viscose rayon)longrightarrow8 combination: Aa, Av, Ra, Rv, Ca, Cv, Wa, Wv: the simplified character] The results of this study can be summarized as follows : 1. For the regional thermal resistance the differences in eight clothes as well as differences in each part were significant. As a whole the breast part showed the highest thermal resistance and the leg part was higher than the shank part. The rank of the total thermal resistance was put at Wa>Wv>Ca>Cv>Aa>Av>Ra>Rv in this order. 2. Considered clothing microclimate microclimate temperature has a similar tendency to the total thermal resistance. It showed a significance in the differences of eight clothes and each parts. the belly part was highest in every combination. On the other hand for clothing humidity there was a significance between back and breast part only in the human wearing test. 3. It was indicated that CLO value was highly positively correlated with the clothings' weight and showed a high negative correlation with the air permeability.

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A Study on the Plasma Biochemical Indices of Heat-Stressed Broilers

  • Lin, H.;Du, R.;Gu, X.H.;Li, F.C.;Zhang, Z.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.9
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    • pp.1210-1218
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    • 2000
  • Four experiments were conducted to evaluate the effect of temperature and humidity on biochemical indices of Arbor Acres broilers at different weeks of age. The alkaline phosphatase (AKP), acid phosphatase (ACP), lactic dehydrogenase (LD), creatine kinase (CK), plasma glucose (Glu), calcium (Ca), potassium (K), chloride (Cl), urea nitrogen (UN), uric acid (UA), plasma thyroxin (T4), triiodothyronine (T3) and insulin levels were determined in all the four experiments. In experiment 1, the plasma Glu, LD and CK levels were increased by heat exposure ($35{^{\circ}C}$ and 35, 60, or 85% RH, 2 h) and this effect was aggravated by longer exposure (24 h). No significant changes (p>0.05) were found in Ca concentration, activity of AKP and ACP. In experiment 2, temperature (10, 20, 30, $33{^{\circ}C}$) had significant effect on the levels of K, Cl, UN, UA levels and the activity of LD (p<0.01), but had no significant influence on the activity of CK (p>0.05). The UN, UK and LD levels were elevated by low temperature $(10{^{\circ}C})$ (p<0.01), Cl content was increased by high temperature ($(33{^{\circ}C})$ (p<0.01), and K level was decreased by high ($(33{^{\circ}C})$ or low $(10{^{\circ}C})$ temperature and increased by medium temperature $(30{^{\circ}C})$ (p<0.01). The humidity (35, 85% RH) only had significant effect on Cl concentration which was decreased by high humidity (p<0.01). In experiment 3, the result showed that only the LD and CK activity were significantly increased (p<0.01) by high temperature (7, 24, 28, $32{^{\circ}C}$) or high humidity (35, 85% RH). Temperature and humidity had no significant effect on K, Cl, UA, UN and Glu levels (p>0.05). In experiment 4 (24, 27, 30, $33{^{\circ}C}$; 30, 45, 60, 75, 90% RH), plasma T3 level was declined by high temperature $(33{^{\circ}C})$, and this phenomena disappeared in birds under high temperature and high humidity environment. T4 concentration in plasma was not affected by temperature (p>0.05), but was increased by high or low humidity (p<0.01). Neither temperature nor humidity had significant effect on plasma insulin concentration (p>0.05). The results of the four experiments suggested that broilers at different growth periods might have different thermal requirements and would response differently to heat exposure. The plasma biochemical indices themselves had big variation; the reaction of the indices to thermal exposure treatment differed with the age of broilers. The big variation of biochemical indices themselves might cover the response of indices to temperature and humidity treatments.

Characteristics of Reliability for Flip Chip Package with Non-conductive paste (비전도성 접착제가 사용된 플립칩 패키지의 신뢰성에 관한 연구)

  • Noh, Bo-In;Lee, Jong-Bum;Won, Sung-Ho;Jung, Seung-Boo
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.4
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    • pp.9-14
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    • 2007
  • In this study, the thermal reliability on flip chip package with non-conductive pastes (NCPs) was evaluated under accelerated conditions. As the number of thermal shock cycle and the dwell time of temperature and humidity condition increased, the electrical resistance of the flip chip package with NCPs increased. These phenomenon was occurred by the crack between Au bump and Au bump and the delamination between chip or substrate and NCPs during the thermal shock and temperature and humidity tests. And the variation of electrical resistance during temperature and humidity test was larger than that during thermal shock test. Therefore it was identified that the flip chip package with NCPs was sensitive to environment with moisture.

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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.

Study on the Reliability of COB Flip Chip Package using NCP (NCP 적용 COB 플립칩 패키지의 신뢰성 연구)

  • Lee, So-Jeong;Yoo, Se-Hoon;Lee, Chang-Woo;Lee, Ji-Hwan;Kim, Jun-Ki
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.3
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    • pp.25-29
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    • 2009
  • High temperature high humidity and thermal shock reliability tests were performed for the board level COB(chip-on-board) flip chip packages using self-formulated and commercial NCPs(non-conductive pastes) to ensure the performance of NCP flip chip packages. It was considered that the more smaller fused silica filler in prototype NCPs is more favorable for high temperature high humidity reliability. The failure of NCP interconnection was affected by the expansion of epoxy due to moisture absorption rather than the fatigue due to thermal stress. It was considered that the NCP having more higher adhesive strength seems to be more favorable to increase the thermal shock reliability.

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Evaluation of Environmental Comfort of Tractor Cabs (트랙터 안전캡의 환경 쾌적성 평가)

  • Hwang, Ki-Young;Kim, Kyeong-Uk
    • Journal of Biosystems Engineering
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    • v.34 no.1
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    • pp.1-7
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    • 2009
  • In order to evaluate environmental comfort of tractor cabs, temperature, relative humidity and noise within the cab were taken from 31 tractors during plowing and rotovating operations. The temperature and humidity were evaluated with regard to the comfort zone of KS B ISO 14269-2 and PMV of ISO 7730. The noise was evaluated with regard to the permissible sound level of OSHA for daily exposure of 8 hours. The collected data indicated that thermal environment of the cabs was out of the comfort zone, which meant tractor operators worked under uncomfortable thermal conditions. Difference in the thermal comfort by tractor power and maker, and type of works was not found. However, 25% of the studied tractors showed PMV in a range of -0.5 to +0.5, which indicated their operators worked under the comfort criteria. PMV was improved when the cab was air-conditioned. Levels of measured cab noise were lower than the permissible criteria, and 76.7% of the studied tractors had cab noise ranged from 75 to 85 dBA. There was a tendency that high powered tractors, rotovating operations and locally-made tractors had greater cab noise levels. However, their differences were insignificant.

Efficacy of Cooling Vest for Auxiliary Body Cooling in Hot Environments (1) -Thermophysiological Response of Human Body in Local Cooling- (고온환경 하에서 착용하는 인체냉각 보조도구로서의 Cooling Vest 연구(1) -Local Cooling에 따른 인체의 온열생리학적 특성-)

  • Kwon, Oh Kyung;Kim, Jin-A;Kim, Tae Kyu
    • Fashion & Textile Research Journal
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    • v.2 no.3
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    • pp.265-271
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    • 2000
  • Heat stress results in fatigue, a decline in strength, alertness., and mental capacity. The problem is compounded when high humidity exists. To help relieve worker heat stress, many types of cooling units are marketed. While workers may experience some cooling, critical body core temperatures often continue to elevate. This study was designed to find the effects of three kinds of cooling vest with portable frozen gel strips on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperature as well as sweat rate and clothing microclimate were measured during 80 min in 5 healthy males. Inquiries were also made into the subjective rating thermal, humidity comfort, and fatigue sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal temperature was the lowest in garb A1, intermediate in garb A, and the highest in garb A2 throughout the experiment. And mean skin temperature was the lowest in garb A, intermediate in garb A1, and the highest in garb A2; (b) Temperature and humidity within clothing (back) were garb in Al, intermediate in garb A, and the highest in garb A2. But the temperature and humidity within clothing (chest) were garb in A, intermediate in garb A1, and the highest in garb A2; (c) Most participants (4 out of 5 persons) answered that they felt more comfortable and fatigueless in garb A1 than in garb A and A2. It is concluded that local cooling in garb A1 of the upper torso could physiological reduce the thermal strain in participants wearing cooling vest.

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Development of high-efficiency heating system using humidifying particles (가습 입자를 활용한 고효율 난방 시스템 개발)

  • Lee, Jeong-Won;Hong, Kyung-Bo
    • Design & Manufacturing
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    • v.14 no.4
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    • pp.17-24
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    • 2020
  • Products for heating indoors in low temperature and dry winter are largely divided into products using fossil fuels and products using electricity. The fossil fuels can warm the entire space by convection, but there is a high risk of fire and the frequent ventilation due to the increase in carbon monoxide and carbon dioxide. Heaters using electricity are mainly used because they are convenient to use and are cheap. However, these products can not efficiently warm the air because they use radiation energy. In other words, only the front part exposed to the heater is warm, and the rear part has no heating effect at all. Also, because it emits a large amount of light, fatigue of the eyes is very high. Another problem is that when using electric heaters, the room tends to be dry by high heat. Indoor humidity maintenance is a very important factor in the prevention and treatment of respiratory diseases. Especially, it is essential for health care for infants, bronchial organs and people with weak respiratory because humidity is low in winter. In this study, we conducted a study to develop a product that can improve heating efficiency while maintaining proper indoor humidity by combining heat energy and moisture particles. The concept of humidification and heating at the same time, moisture particles generated in the humidifier pass through the heater, include thermal energy, and the moisture particles with thermal energy are diffused into the space by forced convection, thereby warming the entire space. In addition, the heating time is shortened as the feeling temperature is increased with the high relative humidity, and this has the effect that the heating cost in winter is reduced.

Design and implementation of thermoelectric dehumidifier using pottier module (Pottier소자를 이용한 열전 제습기 설계 및 구현)

  • 장재철;양규식
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.671-679
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    • 1999
  • In this paper, humidity measurement is accomplished using humidity sensor, dehumidify is implemented using general-purpose $\mu$-processorPIC16C54 and thermoelectric module for control measured humidity and input target humidity value proportionally Pottier module product is variety kind of size and characteristic, very important drawing factor is selection necessary heat sink, which is maintain proper thermal resistance from variety kind of module also. From electronic dehumidifier is manufacture by using thermoelectric module, no sound, no vibration, low power consumption of partial space efficient dehumidify proves the validity of this system.

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