• Title/Summary/Keyword: Heating effect

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Effects of Local Heating on Whole Body Skin Temperature - Centered on the Comparison of Old Women & Female Collegians -

  • Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.6 no.3
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    • pp.84-93
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    • 2002
  • The purpose of this study was to design functional clothing based on the physical characteristics of old women. The subjects of this experiment were 5 healthy old women and 5 college women. While the subjects were exposed to the circumstances of $28{\pm}0.5^{\circ}C$ and local heating at 7 areas (chest, abdomen, back, loin, hand, thigh and instep), their skin temperature, physiological reaction and psychological reaction were determined. The conclusions about the effects of local heating are as follows : 1. Skin temperature before heating was in the order of head-neck> trunk> upper limbs> lower limbs (Group A: old subjects) and head-neck> trunk> lower limbs> upper limbs (Group B: young subjects). 2. The heating pad was attached and detached for 30 minutes each. The sharpest rise and fall were recorded at 5 minutes with the pad on and off. Both groups had great changes in the body parts near trunk. 3. With the pad on and off, both groups showed no change in body temperature, blood pressure, and pulse rate. 4. Concerning the pervasive effects of local heating on whole body skin temperature, loin heating greatly increased other body parts in Group A. In Group B, the effects were large in heating chest, abdomen, back, loin, and thigh. 5. The loin part of old women has the greatest pervasive effect of local body heating.

The Effect of globule size on the Mechanical Properties in Reheating Process of Aluminium Alloys (알루미늄소재의 재가열 공정에서 구상화의 크기가 기계적 성질에 미치는 영향)

  • 박상문;강충길
    • Transactions of Materials Processing
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    • v.11 no.2
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    • pp.155-164
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    • 2002
  • One of the important steps on semi-solid forming Is the reheating process of raw materials to the semi-solid state. This Process is not only necessary to achieve the required SSM billet state, but also to contro1 the microstructure of the billet. In reheating process, the globule size is determined by the holding time of last heating stage. Therefore, some experiments to investigate the relationship between the mechanical properties and the holding time in the last heating stage was performed. The alloys used in this experiment were 357, 319 and A390 alloys. The experiments of reheating were performed by using an Induction heating system with the capacity of 50kw. This paper shows the evolution of the microstructure according to the holding time of last reheating stage. Furthermore, to evaluate the effect of globule size controlled by holding time in last heating stage uniaxial tension test was performed. The strain-stress curves were plotted according to the holding time.

A Study on the Drawability of Rectangular Deep Drawing of Sheet Metal using Local Heating (국부가열을 이용한 박판의 사각통 디이프 드로잉 성형에 관한 연구)

  • 박동환;김창호;강성수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.04b
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    • pp.209-214
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    • 1995
  • This paper describes that the effects of punch speed and temperatures of the die and the blank holder on the drawability are examined. Up to now, multi-stage of dies sets have been used generally at room temperature in deep drawing of rectangular shaped components. But using local heating, it is shown that one stage of die set was capable of deep drawing and the drawability was increased and sheet thickness of component was drawn somewhat uniformly. Rectangular deep drawing experiments on two kinds of stainless steel STS316L, STS430 of 1.0 mm thickness have been conducted using local heating. The limiting drawing height can be increased by heating the die and the blank holder up to 100 .deg. C at STS316L. Commercial lubricants hadn't an effect on drawability in rectangular deep drawing, but vinyl and teflon film had an effect on it.

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Experimental Study on the Radiative and Convective Cooling of Electronic Modules opposed to a Heated Vertical Plate (가열 수직 평판과 마주보는 전자모듈의 복사 및 대류 냉각에 대한 실험적 고찰)

  • Choi, In-Su
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.2
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    • pp.105-112
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    • 2005
  • The characteristics of natural convection heat transfer combined with radiation in a vertical parallel plates has been investigated experimentally. The vertical channel is consisted with a heated wall and three protruding heating sources attached on the opposite wall. The cooling of modules has been experimented with heating the wall as well as modules themselves at different aspects ratios and heating fluxes. As the location of module is higher, the temperature becomes higher, but the increasement is smaller. When the aspect ratio is lower than 26, its effect on the temperature is not significant rather than that of the radiation heat transfer. Furthermore, the correlation of Nusselt number with the Rayleigh number are attempted, but additional treatment is needed to accomodate the cases of heating module and/or opposite wall.

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effect of Heating Rate on the Mechanical Properties in the Crystallization of $Li_2O$.$2SiO_2$ Glass ($Li_2O$.$2SiO_2$유리의 결정화에서 승온속도가 기계적 특성에 미치는 영향)

  • 최병현;고경현;안재환;지응업
    • Journal of the Korean Ceramic Society
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    • v.33 no.7
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    • pp.809-815
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    • 1996
  • When Li2O.2SiO2 glass was crystallized between the temperature of maximum nucleation and the temperature of maximum crystal growth it was found that the control of heating rate had serious effect on the crystallinity and microstructure and the greatly changed physical properties. Density and elastic modulus tends to increase but thermal expansion coefficient decreased with increased crystallinity. When heating rate between the tempe-rature of maximum nucleation and the temperature of maximum crystal growth was 10~5$0^{\circ}C$/hr. crystallinity was increased to result in the increment of strength. When nuclation was done at 44$0^{\circ}C$ for 5 hours and the temperature of crystal growth was held at 575$^{\circ}C$ strength was increased until crystallinity reached 65% and strength was decreased with higher crystallinity. These phenomena could be explained that even for the same crystallinity different heat rates resulted in different number and size of cracks.

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Analysis of Thermal Performance of a Solar Heating & Cooling System (태양열 냉.난방시스템의 열성능 분석)

  • Kwak, Hee-Youl;Shin, U-Cheul
    • Journal of the Korean Solar Energy Society
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    • v.28 no.4
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    • pp.43-49
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    • 2008
  • The purpose of this study is to present the simulation results and an overview of the performance assessment of a solar heating & cooling system by means of the $200m^2$ evacuated tube solar collector. The simulation was carried out using the thermal simulation code TRNSYS with new model of a single-effect LiBr/$H_{2}O$ absorption chiller developed by this study. The calculation was performed for yearly long-term thermal performance and for two design factors: the solar hot water storage tank and the cold water storage tank. As a result, it was anticipated that the yearly mean system efficiency is 46.7% and the solar fraction for the heating, cooling and hot water supply are about 84.4 %, 41.7% and 72.4%, respectively.

Effects of Phase Change Material Floor Heating Systems using Direct Solar Gain on Cooling Load (직달일사를 이용한 잠열축열식 바닥난방 시스템이 냉방부하에 미치는 영향에 대한 검토)

  • Kim, Soo-Kyung
    • Journal of the Korean Solar Energy Society
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    • v.33 no.3
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    • pp.9-16
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    • 2013
  • In this research, the effect of a heating system, which is powered by direct solar energy accumulated in phase change material (PCM) as heat storage material installed on the floor surface, on the cooling load was studied. Cooling load of a test building designed for this research was measured with fan coil unit and factors affecting it were also estimated. Experiments were performed with and without PCM installed on the building floor to understand the effect of the PCM on the cooling load. Additionally, to confirm the experiments results, the prediction calculation formula by average outside temperature and integrated solar radiation was composed using multivariate regression model. The results suggested that the heating system with PCM on the floor surface has the potential to shift electric power peak by radiating heat, stored during the daytime in it, at night, not increasing the total cooling load much.

Effect of Step-up and Step-down Hyperthermia on Skin of Mice (온열요법시 온도변화가 정상조직에 미치는 영향)

  • Choi, Ihl-Bohng;Kim, Choon-Yul;Bahk, Yong-Whee
    • Radiation Oncology Journal
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    • v.6 no.2
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    • pp.155-161
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    • 1988
  • The usefulness of hypertermia for cancer therapy have well been established. The purpose of the present investigation was to ascess the effect of step-up $(42^{\circ}{\rightarrow}44^{\circ}C$ sequence) and step-down $(44^{\circ}{\rightarrow}42^{\circ}C$ sequence) heating on the skin of the hind foot of the mouse. Hyperthermic treatments were given by immersion the hind foot of the mouse in circulating water baths. Skin response was studied by the leg reaction, which was scored according to a numerical scoring system proposed by Urano et al (1980). The results were as follows 1. The skin damage of $44^{\circ}C$ control group was more severe than $42^{\circ}C$ control group (P<0.05), except for 15 min. heating group. 2. The Skin damage of step-down group was more severe than step-up group (P<0.05). 3. The skin damage of $44^{\circ}C$ control group was more severe than step-up group when there is no difference in $44^{\circ}C$ heating time of step-up group from $44^{\circ}C$ control group (P<0.05). 4. In step-down group, the skin damage was more severe than $44^{\circ}C$ control group after preheating 45 min at $44^{\circ}C$ (P<0.05). Therefore, the above findings suggest the normal tissue damage by step-up heating was correlated with heating time of post step-up. The dropping of heating temperature in late phase had more severe damage of the skin than that in early phase during hyperthermia, and so contineous control of satisfactory temperature should be considered as the one of the most important factor for prognosis, complications of clinical hyperthermia

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Heating and Cooling Energy Conservation Effects by Green Roof Systems in Relation with Building Location, Usage and Number of Floors

  • Son, Hyeong Min;Park, Dong Yoon;Chang, Seong Ju
    • KIEAE Journal
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    • v.14 no.2
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    • pp.11-19
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    • 2014
  • Building energy consumption takes up almost 25% of the total energy consumption. Therefore, diversified ways, such as improving wall and window insulation, have been considered to reduce building energy consumption. Recently, green roof system has been explored as an effective alternative for dealing with reducing heating and cooling energy, thermal island effect and improving water quality. However, recent studies regarding a green roof system have only focused on building energy reduction without considering the applied usage, location, and story of the green roof system. Therefore, this study pays attention to the heating and cooling energy in relation to the applied usage, location, and story of a green roof system for investigating its impact on energy reduction. The result of simulations show that the reduction in heating energy consumption is higher when applied to Cherwon-gun province which has a continental climate condition, compared to the city of Busan that is distinguished by its warm climate. Cooling energy saving turns out to be higher when the green roof system is applied to Busan in comparison with Cherwon. As for the applied usage or function of the building, residential space acquires the highest heating and cooling energy saving effect rather than commerce, educational or office space because of HVAC's running time based on usage. When it comes to the story of the green roof, both heating and cooling energy saving become the highest when the green roof is applied to single-storied buildings. The reason is that single story building is affected by the ground largely. Generally, the variations of heating energy consumption are larger than the cooling energy consumption. The outcome of the simulations, when a green roof system is applied, indicates that the energy consumption reduction rate is dynamically responding to the applied usage, location, and story. Therefore, these factors should be counted closely for maximizing the reduction of energy consumption through green roof systems.

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.