• 제목/요약/키워드: external heat

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Effect of Ohmic Heating on External and Internal Structure of Starches (옴가열이 전분의 외부와 내부 구조에 미치는 영향)

  • Cha, Yun-Hwan
    • The Korean Journal of Food And Nutrition
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    • v.28 no.1
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    • pp.126-133
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    • 2015
  • Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when the electrical current is transmitted into. Prior to the study, we have researched the potato starch's thermal property changes during ohmic heating. Comparing with conventional heating, the gelatinization temperature and the range of potato starch treated by ohmic heating are increased and narrowed respectively. This result is appeared equally at wheat, corn and sweet potato starch. At this study, we treated potato, wheat, corn and sweet potato starch by ohmic/conventional method and observed change of external structure by microscope and internal structure by X-ray diffractometer. Conventional heated at $55^{\circ}C$ potato starch was not external structural changes. But ohmic heated potato starch is showed largely change. Some small size starch particle were broken or small particles are made of larger particle together or small particles caught up in the large particle. Changes in ohmic heated potato starch at $60^{\circ}C$ was greater. The inner matter came to an external particle burst inside and only the husk has been observed. The same change was observed in the rest of the starch. The change of internal structure of potato starch was measured using X-ray diffraction patterns. There was no significant difference between ohmic and conventional heating at $55^{\circ}C$. But almost every peak has disappeared ohmic at $60^{\circ}C$. Especially $5.4^{\circ}$ peak to represent the type B was completely gone. When viewed from the above results, external changes with change in the internal crystal structure of the starch particles were largely unknown to appear. In conclusion, during ohmic heating changes of starch due to the electric field with a change in temperature by the heating was found to have progressed at the same time.

Study of Air Flow Effects on Heat Characteristics of Warm Needle Acupuncture (온침 열특성의 기류 영향에 관한 연구)

  • Kim, Jung-Wo Roy;Lee, Hye-Jung;Yi, Seung-Ho
    • Korean Journal of Acupuncture
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    • v.27 no.4
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    • pp.35-47
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    • 2010
  • Objectives : To characterize the thermal properties of traditional warm needle and new warm needle with various air flows as an important environmental factor and to suggest the necessity of maintaining suitable environment of clinics to maximize their efficacy. Methods : We measured the temperature characteristics of traditional moxa warm needle and new moxa charcoal warm needle by applying an automatic temperature acquisition system with thermocouples while external various air flows were supplied. Temperatures of two positions at the needle body were measured while a moxa cone burned. Typical temperature characteristics like peak temperature, duration, curve shape and the efficiency of the heat stimuli by heat amount analysis were executed. Results : Both warm needles showed similar temperature curve with an increase in the air flow. Peak temperature and duration of effective heat decreased with the air flow, as shown in indirect moxibustion on garlic. The temperature change pattern by the air flow became more apparent when the total combustion heat was compared with the effective heat. The values from two positions on the needle body were significantly different, showing a distance dependency from the heat source of warm needle acupuncture. Conclusions : Thermal properties of warm needle acupuncture was observed variously with surrounding air flow of 0.0 - 0.7 m/s. It emphasized the importance of environmental control as well as the warm needle itself such as heat source and needle. The latter has already been known to deliver designated heat to subjects. It also indicated the importance of education and skill of the practitioners of warm needle acupuncture.

A Study on the Manufacturing Technology for the Development of Heat Pipes with a Sintered Metal Wick (소결 금속 윅 히트파이프 개발을 위한 제조 기술 연구)

  • Choi, Jee-Hoon;Kim, Sung-Dae;Sung, Byung-Ho;Roo, Seong-Ryou;Park, Hyung-Ki;Kim, Chul-Ju;Ko, Han-Seo
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.479-482
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    • 2006
  • The most the electronic industry has recently accelerated the modularization, the miniaturization and the high integrated trend of electronics fields such as electronics components, appliances and etc., the most increasingly the heat generation problem rises. Even though the conventional cooling technologies are widely used in order to reduce the heat loads, the technologies are not easy to meet the present trends due to the fact that most of many conventional methods are relative to external form environments such as size, design and so on. With regardless of those environments, however, a heat pipe is one of the most efficient systems to improve the heat transfer performance. And then the performance of the heat pipe depends on a wick structure. Of various wick structures, sintered metal wick is known so that it has some advantages such as smaller pore size, increasing porosity as well as high reliability. In this study sintered metal wicks, thickness 0.7 mm, 0.8 mm and 0.9 mm, were manufactured as of $100{\mu}m$ copper powder to obtain the manufacturing technology of heat pipes mounted with a sintered metal wick. Furthermore, experiments for the operational performance factors such as capillary limit, thermal resistance were not only performed but also compared with a theoretical model simultaneously. Experimental results agreed with the theoretical model, and then it seems to be required to study various development processes of sintered metal wicks for the high performance of a heat pipe system.

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A Combustion Characteristic Analysis of Sandwich Panel Core Using Radiation Heat Flux (복사열을 이용한 샌드위치 패널 심재의 연소특성 분석)

  • Park, Hyung-Ju
    • Fire Science and Engineering
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    • v.21 no.4
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    • pp.25-31
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    • 2007
  • The combustion characteristics and combustion heat of sandwich panel cores were analysed using variable external irradiation level. The characteristics such as ignition time, critical heat flux, ignition temperature and surface temperature profile were measured. Fuel samples were exposed to incident heat fluxes from 15 to $50\;kW/m^2$. For the measurement of various combustion characteristics, the size of specimen was $100\;mm\;{\times}\;100\;mm\;{\times}\;50\;mm$ and the samples were 3 different kinds. As results, Type B showed the best characteristics in measurement of combustion heat and ignition temperature and Type C showd the best characteristics in critical heat flux and surface temperature profile than that of the other two. In conclusion, we knew that Type C had the best performance in fire safety from all data of this study.

A Study for Control of Thermal Cracking by Heat of Hydration in Subway Concrete Box Structure (지하철 콘크리트 BOX 구조물의 수화열에 의한 온도균열 제어 방안 연구)

  • Song, Suk-Jun;Yoo, Sang-Geon;Park, Ji-Woong;Kim, Eun-Kyum
    • Journal of the Korean Society for Railway
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    • v.12 no.6
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    • pp.1024-1029
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    • 2009
  • According to increase of massive concrete structures, Thermal crack done by heat of hydration have been increased in a process of the execution. In case of a subway concrete box structure, thickness of structures are almost over 1 meter, and penetrating crack by external restraint takes a bad effect on the durability with a water leakage and deterioration in especially concrete wall. A try of shortening a constructing period often occurs as subway is generally constructed according to a road to decrease a traffic jam. The research proposes executing method by skipping one block as a plan of shortening a constructing period and investigate an influence on thermal cracking control. Additionally, sensitivity analysis is accomplished by changing a height of a concrete wall, and concrete placing and air temperature met with a field condition.

HyungSang Medical Approach to Detoxification (동의보감(東醫寶鑑) 해독 처방에 대한 형상의학적 고찰)

  • Kim, Jong-Won;Jeon, Soo-Hyung;Jung, Heung-Sik;Kang, Kyung-Hwa;Lee, In-Sun;Lee, Sang-Hoon;Kim, Kyu-Kon;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.2
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    • pp.278-287
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    • 2009
  • Ji-San, the founder of HyungSang medicine, emphasized food intake and detoxification by stating, "Korean medicine begins with detoxification." Toxin accumulates in one's body unless the internal and external conditions stay in their harmony. The accumulation of toxin is also caused by western medication or one-sided diet, and detoxification should be considered in those cases. HwangRyunHaeDok-Tang reduces fire and heat, and the lesion is likely to locate in the upper body. BangPoongTongSung-San can be used for systemic disease. IkWoon-San also reduces fire and heat but mainly focuses on promoting urination. InSamPaeDok-San has an effect of curing the external symptoms of SangHan(傷寒), in addition to detoxification. SeoGakJiHwang-Tang, SoDok-Eum, and SeoGakSoDok-Eum can resolve the heat-toxin when it is located on the surface. SibJeonDaeBo-Tang enhances the detoxifying function of human body. GhamDu-Tang and JaGeum-Jung have a general effect on detoxification.

The Literature Study on the Urine Therapy (요요법(尿療法)에 대한 문헌적 고찰)

  • Jung, Dae-Ho;Cho, Chung-Sik;Kim, Chul-Jung
    • Journal of Haehwa Medicine
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    • v.14 no.1
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    • pp.51-57
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    • 2005
  • Though the literature study on the urine therapy, we concluded as follows. It Almost use urine, healthy child's of under 10-12 age, and the gathering takes the middle part of urine. It Almost drinks fresh urine warmly. It drinks urine with Zingiber is Rhizoma Recens juice and Allii Radix or Sappan Lignum and Achyranthis Bidentatae Radix which is hwa-hyeol-geo-eo medicine in vomiting blood nosebleeding, with Allii Radix and Sojae Semen Praeparatum in a headache, with bile of pig in symptoms of shang han jue yin, with Zingiberis Rhizoma Recens juice Ginseng Radix's powder in doing the colon good or person have weak spleen and stomach as well as deficiency of qi with Bambusae Caulis in Liquamen or Zingiberis Rhizoma Recens juice in heat movement by deficiency of blood (eum-heo-hwa-dong) with Perillae Fructus, Mori Cortex and Adenophorae Radix which hwa-dam-ji-hae medicine and sparagi Radix, Liriopis Tuber Schizandrae Fructus which is bo-eum medicine in a cough by deficiency of blood(eum-heo-hae-su). Also it followed in condition and the honey little quantity alcoholic beverage it put in and with the urine it drinks it did. The case which the skin bursts Injury by biting. The eye comes to be red and smart in consequence of the fact that it swells, it pastes the warm urine in the wound region. In consequence of the fact that beriberi disease or to the case which is fed up the finger, it soaks the wound region in the urine. It was used in the external medical therapy which is various even on the thing outside which it drinks. It does not use or must use very prudently to person who has deficiency of gi and blood, weak stomach, not heat and fake heat.

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A Study on the Combustion Characteristics of Phenol Foam (페놀 폼의 연소특성에 관한 연구)

  • Park, Hyung-Ju
    • Fire Science and Engineering
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    • v.24 no.1
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    • pp.122-127
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    • 2010
  • The combustion characteristics of phenol foam were analysed using variable external irradiation level (20, 25, 35, 50, and $70kW/m^2$) and in the mixture gas of oxygen/nitrogen. The oxygen index were carried out from the oxygen index tester (KS M ISO 4589-2) and ignition time, critical heat flux, and mass loss rate were carried out from the mass loss calorimeter (ISO 5660-1). As the results of this study, the critical heat flux and average mass loss rate were $28.99kW/m^2$ and $0.56{\sim}1.77g/m^2s$ respectively at the variable external irradiation level. And the limited oxygen index were 45.1% in mixture gas of oxygen/nitrogen. In conclusion, we knew that phenol foam had the best performance than other foam materials in fire safety from all data of this study.

A Case Study of Different Configurations for the Performance Analysis of Solid Oxide Fuel Cells with External Reformers (외부 개질형 평판형 고체 산화물 연료전지 시스템 구성법에 따른 효율특성)

  • Lee, Kang-Hun;Woo, Hyun-Tak;Lee, Sang-Min;Lee, Young-Duk;Kang, Sang-Gyu;Ahn, Kook-Young;Yu, Sang-Seok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.3
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    • pp.343-350
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    • 2012
  • A planar solid oxide fuel cell (PSOFC) is studied in its application in a high-temperature stationary power plant. Even though PSOFCs with external reformers are designed for application from the distributed power source to the central power plant, such PSOFCs may sacrifice more system efficiency than internally reformed SOFCs. In this study, modeling of the PSOFC with an external reformer was developed to analyze the feasibility of thermal energy utilization for the external reformer. The PSOFC system model includes the stack, reformer, burner, heat exchanger, blower, pump, PID controller, 3-way valve, reactor, mixer, and steam separator. The model was developed under the Matlab/Simulink environment with Thermolib$^{(R)}$ modules. The model was used to study the system performance according to its configuration. Three configurations of the SOFC system were selected for the comparison of the system performance. The system configuration considered the cathode recirculation, thermal sources for the external reformer, heat-up of operating gases, and condensate anode off-gas for the enhancement of the fuel concentration. The simulation results show that the magnitude of the electric efficiency of the PSOFC system for Case 2 is 12.13% higher than that for Case 1 (reference case), and the thermal efficiency of the PSOFC system for Case 3 is 76.12%, which is the highest of all the cases investigated.

Change in Pulpal Blood Flow of Heat-induced Neurogenic Inflammation in Feline Dental Plup (고양이 치수에서 열 자극으로 유도된 신경병증 염증에서 치수 혈류량 변화)

  • Park, Min-Kyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.12
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    • pp.6340-6345
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    • 2013
  • This study examined the involvement of histamine in heat-induced changes in pulpal blood flow(PBF) to determine the mechanism of neurogenic inflammation in feline dental pulp. The experiments were carried out in 10 felines anesthetized with sodium pentobartial and histamine injected into the dental pulp through the external carotid artery. The change in the pulpal PBF was measured using a laser Doppler flowmeter(Periflux 4001, Stockholm, Sweden). The probe of laser Doppler flowmeter was placed on the buccal surface of the ipsilateral canine teeth. Heat was applied to the tooth using a heat stimulator controlled script file with an input/output device. The application of heat ($40-65^{\circ}C$) induced a significant increase in PBF. The application of histamine($5{\mu}g/kg/1ml$) followed by heat($45^{\circ}C$) resulted in an increase in PBF. Therefore, the results of the present study showed that heat and histamine are capable of vasoconstriction caused by neurogenic inflammation in feline dental pulp. In addition, neurogenic inflammation plays an active role in modulating the microcirculation of the dental pulp.