• Title/Summary/Keyword: Local heating

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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.

Low Temperature Growth of High-Quality Carbon Nanotubes by Local Surface Joule Heating without Heating Damage to Substrate

  • Heo, Sung-Taek;Lee, Dong-Gu
    • Carbon letters
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    • v.10 no.3
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    • pp.230-233
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    • 2009
  • In this study, a low temperature growth of high-quality carbon nanotubes on glass substrate using a local surface heating without heating damage to substrate was tried and characterized. The local joule heating was induced to only Ni/Ti metal film on glass substrate by applying voltage to the film. It was estimated that local surface joule heating method could heat the metal surface locally up to around $1200^{\circ}C$ by voltage control. We could successfully obtain high-quality carbon nanotubes grown at $300^{\circ}C$ by applying 125 V for joule heating as same as carbon nanotubes grown at $900^{\circ}C$.

A Study on Characteristic of High Frequency Induction Heating for Local Heating (국부가열용 고주파 유도가열 특성에 관한 연구)

  • Jin, Hyung-Kook;Lee, Dong-Ju;Shin, Sang-Beom
    • Proceedings of the KWS Conference
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    • 2010.05a
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    • pp.60-60
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    • 2010
  • Since the curved hull plate was made by a series of manufacturing process including cold bending, manual local heating and correction work, the accuracy of curved plate strongly depends on the proficiency of worker. So the demands on the automatic local heating system for curved hull plate have continuously increased and the various researches relevant to it have been performed. Generally, the heat sources used for local heating were flame and induction heat. In terms of initial cost, flame heating is in a better favorable position than induction heating. However, from the viewpoint of the control of heat, induction heating has more advantage. So the various researches related to apply the induction heating to the automatic forming system has been performed. The purpose of this study is to establish the proper capacity of high frequency induction heating system for forming the curved hull plate. In order to do it, the proper coil shape for local heating was designed and the efficiency of induction heating system was determined by comparing of temperature results obtained by FEA and experiment. With the results, the extensive FEA was performed to identify the effect of heated plate dimension, cooling method and the capacity of induction heating system on the amount of heat loss introduced by induction heating. Based on the results, the proper capacity of high frequency induction heating system was proposed.

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Effects of local body heating and cooling on thermogram analysis of the extremity with hot pack (핫팩을 이용한 인체의 부위별 가온과 제거가 사지부 피부 열화상도에 미치는 영향)

  • Kim, Soyoung;Hong, Kyunghi
    • Korean Journal of Human Ecology
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    • v.23 no.6
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    • pp.1205-1215
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    • 2014
  • The purpose of this study was to investigate the effect of local heating and cooling of various body parts on the skin temperature of the exposed extremities including neck. Hot pack was used to warm up the body of seven participants for 15 minutes and it was removed as the temperature of the hot pack decreased after 15minutes of warming. Thermograms of body surface with and without hot pack were analyzed intensively to observe the efficiency of the local heating of shoulder, abdomen, back waist, and foot on the skin temperature of ten area of the subjects' body. The results indicated that the absolute skin temperature of front upper arm and thigh was significantly higher depending on the area of heating, especially, in case of abdomen and foot heating, which was not observed at the back of the body. The rate of skin temperature of extremities such as finger, palm and foot was significantly different depending on the body area of local heating. Generally, it was found that back waist heating was not efficient to warm up and maintain the skin temperature of the body after removing the hot pack.

Multi-point Dieless Forming Technology Using Local Heating Effect (국부가열효과를 활용한 다점성형공정기술)

  • Park, J.W.
    • Transactions of Materials Processing
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    • v.31 no.2
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    • pp.96-102
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    • 2022
  • The multi-point dieless forming technology is one of flexible forming technologies that can form 3D curved surfaces of various shapes utilizing a lot of punch arrangements. A new technology that can simultaneously apply high-temperature forming and flexible forming technology by fusing local heating effect to such multi-point dieless forming technology was proposed in the present study. A simple local heating multi-point dieless forming apparatus was fabricated to confirm the applicability of this new technology. This equipment was designed to be used as a heat source by inserting heating cartridges in the head of the multi-point punch. Cartridges were used for all individual punches. Using the manufactured equipment, the time to raise the temperature to the target temperature and the surface temperature of the punch head part in contact with the plate were measured. In addition, forming experiments were carried out according to sheet material temperature (100 ℃, 200 ℃, and 300 ℃) to obtain forming results for each condition. The applicability and feasibility of this technology were confirmed through experimental results.

A Study on the Infrared Local Heat Treatment of Curved Line for Aluminum Alloy Sheet (알루미늄 판재의 성형성 향상을 위한 적외선 국부 열처리법의 곡선형태 적용에 관한 연구)

  • Lee, E.H.;Yang, D.Y.
    • Transactions of Materials Processing
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    • v.27 no.2
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    • pp.87-92
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    • 2018
  • Auto industries have tried to employ lightweight alloys to improve the fuel efficiency of manufactured vehicles, as the environmental concern becomes an important issue. Even though the aluminum alloy is one of the most appropriate lightweight alloys for auto parts, the low formability of an aluminum alloy has been an obstacle to its application. In order to resolve the low formability problem, a recent study (Lee et al., 2017 [1]) showed that the infrared (IR) local heat treatment can improve the formability with a reduction of heating energy. However, the aforementioned study was limited to only a linear line heating. Since many of the available auto parts as applicable to vehicle manufacturing have a curved line shape, the heating experiments for a curved line should be studied. The possibility of building IR lamps having complex shapes is an advantage of the IR lamp, since it can control the heating shape. This work conducted the IR local heat treatment for the curved line. The experimental results show that the IR local heat treatment can improve the formability of the aluminum alloy for curved line. Additionally, it is shown that the IR local heat treatment also reduces the heating energy when it is compared with the furnace heating which heats a blank as a whole. A numerical simulation with a stress-based forming limit diagram also supports the experimental results.

Local Heating of an Injection Mold using Selective Induction Heating (선택적 유도가열을 사용한 사출금형의 국부가열기술)

  • Do, Bum-Suk;Park, Jung-Min;Eom, Hye-Ju;Park, Keun
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1119-1123
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    • 2008
  • High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a noncontact procedure. It has been recently applied to the injection molding of thin-walled parts or micro/nano structures. Though the induction heating has an advantage in terms of its rapid-heating capacity on the mold surface, it still has difficulty in efficient mold temperature control due to the restriction of an induction coil design suitable for the given mold shape. The present study proposed a localized mold heating method by means of selective use of mold material. For localized induction heating, an injection mold composed of ferromagnetic material and paramagnetic material is used. The electromagnetic induction concentrates on the ferromagnetic material, from which we can selectively heat for the local mold elements. The feasibility of the proposed heating method is investigated through an experimental measurement in terms of the heating efficiency on the localized mold surface.

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The effect of local heating on superconductivities in internal tin processed Nb$_3Sn$ wires (내부 확산법에 의한 Nb$_3Sn$ 초전도 선재에서 부분 가열이 초전도 특성에 미치는 영향)

  • Ha, Dong-Woo;Oh, Sang-Soo;Ha, Hong-Soo;Lee, Nam-Jin;Kwon, Young-Kil;Ryu, Kang-Sik
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.1-5
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    • 2000
  • There is the possibility that internal tin processed Nb$_3Sn$ wires are locally heated during the drawing process and the jacketing process. It is important to know the variations in J$_c$ of internal tin processed Nb$_3Sn$ wires caused by local heating. Internal tin processed Nb$_3Sn$ rods were cold worked to 2.28 mm, using the appropriate reduction ratio, and then cut into several pieces. At this stage, wires were locally 50 mm heat zone heated up to 360$^{\circ}C$. The locally heated Nb$_3Sn$ wires were drawn to a final diameter size of 0.81 mm. Others were cold worked successively to 0.81 mm and locally heated with the same conditions. 2 types of locally heat treated wires were wound on Ti-6Al-4V barrels and heat treated for the Nb$_3Sn$ reaction. Local heating of internal tin processed Nb$_3Sn$ wires after the J$_c$ of these wires. However, local heating at an intermediate stage of the drawing process caused a decrease in J$_c$. When the local heating temperatures were higher than melting point of Sn, non-Cu J$_c$'s decreased significantly. A Sn-Cu alloyed boundary appeared after local heating over the melting point of Sn, and caused work hardening and a decrease in the workability.

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A Study on Solar Heating System Technology Combining Multiple Technology with Mutual-Complementary Method - Low-cost, high efficiency, large-scale use of solar heating system - (다원기술 상호보완식 태양열 난방기술 - 저원가 고효율 규모화 태양열 난방 방안 -)

  • Nan, Bao-Xuan
    • Journal of the Korean Solar Energy Society
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    • v.28 no.6
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    • pp.15-23
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    • 2008
  • The article deals with system technology of a new solar heating system which systematically combines exiting solar collector technology, auxiliary electrical water heating, floor heating system and well insulated construction method and its application of this system to apartment house heating system in the cold region, and also analyzed performance of the new system in terms of technical and economic feasibility. Results shows that energy efficiency approaches up to 50% of the energy consumption of local construction from 1980 to 1981. The implementation of "DQ technology" to floor heating system achieved from 79% to 85% of the energy-saving benefits comparing to other housing units which were supplied by the local district heating plant.

Study on Local Buckling of District Heating Pipes Using Limit State Design (한계상태 설계법을 이용한 지역난방 열배관의 국부좌굴 연구)

  • Kim, Joo-Yong;Lee, Sang-Youn;Ko, Hyun-Il;Cho, Chong-Du
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.12
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    • pp.1829-1836
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    • 2010
  • The district heating system distributes the heat generated from a cogeneration plant to wider locations. In this process, the district heating pipe (DHP) is subjected to internal and external loadings. The internal loadings are generally caused by the operating conditions such as water temperature and internal pressure. Frictional interactions between the pipes and the soil contribute to the external loadings. Thus, investigation of the mechanisms of failure of DHPs will help to guarantee both mechanical stability and heating efficiency. In this study, we investigate the local buckling of DHPs using limit state design (LSD). Two methods are considered: the use of the limit state for the width-thickness ratio and the use of the limit state for the strain. The results are used to confirm that the DHP is stable under local buckling. Finally, we suggest a minimum preheating temperature for avoiding local buckling.