• Title/Summary/Keyword: external heat

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THERMAL CONTROL DESIGN FOR COMS (COMS 특별세션)

  • Jun, Hyoung-Yoll;Kim, Jung-Hoon;Kim, Sung-Hoon;Yang, Koon-Ho
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.199-202
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    • 2007
  • COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean observation and meteorological observation. Conventional thermal control design, using MLI (Multi Layer Insulation), OSR (Optical Solar Reflector), heater and heat pipe, is utilized. Ka-band components are installed on South wall, while other equipment for sensors are installed on the opposite side, North wall. High dissipating communication units are located on external (surface) heat pipe and are covered by internal insulation blankets to decouple them from the rest of the satellite. External satellite walls are covered by MLI or OSR for insulation from space and for rejection internal heat to space. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. Single solar array wing is adopted in order to secure clear field of view of radiant cooler of IR meteorological sensor. This paper presents principles of thermal control design for the COMS.

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Performance Analysis of an Air-Cycle Refrigeration System (공기사이클 냉동시스템의 성능해석)

  • Won, Sung-Pil
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.9
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    • pp.671-678
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    • 2012
  • The objective of this study is to analyze theoretically the performance of an open air-cycle refrigeration system in which environmental concerns increase. The pressure ratio of the external compressor and efficiencies of the components that compose of the system are selected as important parameters. As the pressure ratio of the external compressor increases, the pressure ratio of the ACM compressor is determined high, the refrigerating temperature and capacity increase, the COP decreases, and the total entropy production rate increases. The effect of heat exchanger effectiveness and turbine efficiency on the performance are greater than that of the ACM compressor efficiency. Also the performance of the air-cycle refrigeration system with two heat exchangers has been enhanced like high COP and low total entropy production rate, compared to the system with one heat exchanger.

Literatural study of the cause and mechanism of Eye Disease (眼病의 病因 病機에 對한 文獻的 考察)

  • Gang, Seung-Won;No, Seok-Seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.5 no.1
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    • pp.27-44
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    • 1992
  • The cause and mechanism of eye diseases are follow in biblography. The etiological factor of eye diseases are nearly caused by heat. It is important to distinguish deficiency and substance. In external etiologic factors wind-fever is most of all in six exogenous factors. In internal etiologic factors xu(deficiency) of kidney, blood and fire of seven emotions are lots. In factors other than the internal and external, eating greasy food and hyper-caloric food are a lot of case. In relation with the yin-yang andxu-shi, ther are a lot of eye diseases symptom as dark-dizziness due to the yin-xu of hepatic-kidney. According to eight principles of differentiation of syndromes, syndromes of exterior, heat, shi, almost fall into the category of yang and syndromes of interior, cold, xu, nearly fall into the category of yin. In interior treatment, inducing wind and clearing heat, using Qi and tonifying blood, tonifying and suing of hepatic-kid ney are useful and often used treatment.

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Numerical Analysis for Optimal Design of Heat Exchanger in Air Compressor for Railroad Vehicle (철도차량용 공기압축기의 열교환기 최적 설계를 위한 해석 연구)

  • Kim, Moo Sun;Chung, Jong Deok;Jang, Seongil;Ahn, Joon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.11
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    • pp.570-579
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    • 2017
  • In this study, we examined the multi-stage piston-type air compressors typically used in a railroad vehicle, and the heat transfer efficiency was analyzed according to the design conditions of the heat exchanger (a compressor component module for cooling the compressed high temperature air). For the fin-tube heat exchanger used in the most air compressors, numerical analysis was performed to analyze heat transfer by defining the various rectangle tube sizes and the number of fin-per-unit area as design variables under the same flow rate of compressed air. Also, this analysis compared the temperature of the compressed air. Regarding environmental conditions for analysis, the flow rate of the external cooling air was measured and the mean value of the values was applied. And a "turbulence model" was considered in both the external flow of the cooling air and the internal flow inside the tube. From the results of analysis, it was found that the change of the aspect ratio value of the tube greatly influences the heat transfer efficiency of the compressed air, and influences if the fin density is relatively small. As a result, the optimum design specifications of the heat exchanger for air compressors were confirmed based on the analysis of the heat transfer efficiency, according to the design conditions of fin and tube by the operating temperature range of the compressed air.

A Study on the Fire Risk Comparison of Building Flooring Materials by External Heat Flux (건축용 바닥재의 외부복사열에 의한 화재위험성 비교 연구)

  • Park, Youngju;Kim, Youngtak
    • Journal of the Korean Society of Safety
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    • v.32 no.5
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    • pp.20-24
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    • 2017
  • In this study, we have performed the Cone Calorimeter test in accordance with ISO 5660-1 to check the combustion characteristics of building flooring materials. The fire risk of these materials were evaluated by construction code, KFI criteria and standards of flame retardant performance. When samples exposed to external heat flux, all samples consumed a lot of Oxygen for a long time. So heat release from sample burning continued so long. And also all samples produced so much smoke. Even though a few samples were satisfied with only peak heat release rate criteria, all 8 samples were not satisfied with criteria of peak heat release rate and total heat released together. The results of 5 min total heat released were $15.9MJ/m^2{\sim}5.9MJ/m^2$. It menas the results are more than 2~6 times higher than the criteria. The results of 10 min total heat released were $30.1MJ/m^2{\sim}100.8MJ/m^2$. It means the results are more than 3~12 times higher than the criteria. 6 of 8 samples were not satisfied with Dm.corr.(corrected maximum smoke density) criteria. The building flooring materials which we used for this test ignited very fast and the burning continued so long. It means these samples are susceptible to fire.

A bibliographic study on the external therapy of Acute Mastitis(乳癰Yu-ong) (유선염(乳腺炎) 의 한방(韓方) 외치법(外治法)에 대한 문헌적고찰(文獻的考察))

  • Chang, Sung-Hwan
    • Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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    • v.1 no.1
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    • pp.177-197
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    • 2005
  • Acute Mastitis(急性乳腺炎=乳癰) is an acute suppurative disease appearing in the breast. It is mostly caused by galactostasis, the stagnation of liver-qi(肝鬱) and stomach-heat(胃熱). It is mostly found in breast feeding women, mostly in primiparae. It usually appears in the third and the fourth weeks of postpartum. At the beginning in the chest there appear induration, distending pain, galactostasis, inversion to cold with fever followed by the enlargement of the masses, burning red, megalgia, not subduing of chills and fever, the accumulation of it to form pus. In the early phase it is advisable to follow the therapeutic principles of soothing the liver and clearing away heat, promoting lactation and subduing swelling. After the formation of pus it is advisable to cut radially and drain the pus. External Therapy(外治法) generally refers to all the methods to treat various diseases and symptoms with application of drugs and manipulation or together with proper instruments on the body surface except the method of taking medicine orally Acute Mastitis has been regarded as surgery or the method of taking medicine orally But, based on many bibliographies, acute mastitis was treated by external therapy. Thus through the historical bibliographic studies of external therapy about acute mastitis, this study was made to help the expanding of the methods of treating acute mastitis.

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A Report on Test Results of Fusible-Link Type Heat Responsive Links (Fusible Link Type 감열체 성능시험보고)

  • Gwon, O-Seung
    • Fire Protection Technology
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    • s.10
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    • pp.5-8
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    • 1991
  • This report is explained about test results of heat responsive links for fire protection service, such as fire dampers and fire doors, automatic fire suppression systems and so forth. The testing program was progressed divided by two testing items, external appearance test and performance test. The object of this report is present the problem which appear from the analysis of test results.

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Fabrication and Characteristics Test of Micro Heat Pipe Array for IC Chip Cooling (IC 칩 냉각용 초소형 히트 파이프의 제작 및 성능 평가)

  • 박진성;최장현;조형철;조한상;양상식;유재석
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.7
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    • pp.351-363
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    • 2001
  • This paper presents an experimental investigation on the heat trensfer characteristic of micro pipe (MHP) array with 38 triangular microgrooves. A heat pipe is an effective heat exchanger operating without external power. The heat pipe transfers heat by means of the latent heat of vaporization and two-phase fluid flow driven by the capillary force. The overall size of the MHP array can be put undermeath a microelectonic die and integrated into the electrronic package of a microelectronin device to dissipate the heat from the die. The MHP array is fabricated by micromachining with a silicon wafer and a glass substrate. The MHP was filled with water and sealed. The experimental results show the temperature decrease of 12.1$^{\circ}C$ at the evaporator section for the input power of 5.9 W and the improvement of 28% in the heat transfer rate.

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Literatural study on the cause of the Infantile Vomiting (소아구토(小兒嘔吐)의 병인병리(病因病理)에 관한 동서의학적(東西醫學的) 문헌적(文獻的) 고찰(考察))

  • Han, Jae Kyung;Yoo, Dong Yeol
    • Journal of Haehwa Medicine
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    • v.9 no.1
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    • pp.337-352
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    • 2000
  • According to the literatual study on the Infantile Vomiting since the publication of ${\ll}Hwangjenaekung{\gg}$, the results were as follows. 1. The causes of vomiting are classified into the following kind: external cause are the cold and heat, not external and internal are disorder of food and mood, internal are the dysfuntion of spleen, stomach, liver, kidney. 2. The Oriental Medical cause of Infantile Vomiting is disorder of food, intusion of outside evil, heat accumulation in the stomach, deficiency of stomach liquid, reverse flowing of Qi resulted from fear and being frightened. There are so many causes of Infantile Vomiting, but they are all related to the stomach. 3. The Western Medical cause of Infantile Vomiting are classified with the situation of stimulation, age, accompanied symptom. The main cause related with the age is inhalation of amniotic fluid, maternal blood, infectious disease, wrong lactation method, functional and organic abnormality. 4. The Infantile Vomiting is similar with the adults, but the spleen and stomach of infants is so feeble that the vomiting happens very easily. The reverse flowing of Qi resulted from fear and being frightened and disorder of food are the main cause in infants. 5. The cause of Infantile Vomiting between Oriental Medicine and Western's is so similar and both emphasized the function of spleen and stomach. But the comment on the external cause(cold, heat) and not internal & external cause(mood disorder) is a creative view of Oriental Medicine.

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The Oriental and Occidental bibliographic Study of Psoriasis (乾癬에 對한 東.西醫 文獻的 硏究)

  • Kim, Nam-Kwen;Hwang, Chung-yeon;Lim, Gye-sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.154-178
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    • 1999
  • Psoriasis is the recurrent disease of skin and till now its mechanism, pathogenesis and treatment are not clearly discovered. So, like these papers, we must investigate more safety and effective treatment of psoriasis. And I obtained the following condusions from the Oriental and Occidental bibliographic investigation. 1. In Oriental medicine. Baikbi, Pungsun, Eunselbyong, Songpisun, Baikselpung were the other names of Psoriasis. 2. In Occidental medicine, genetic factors, aggravation and inducible factors, biochemical factors, immunologic factors, disorder of epidermal kinetics, vascular malformation of dermis were cosidered to the pathogenic factors of psoriasis. 3. In Oriental medicine, the pathogenic factors of psoriasis were divided two parts. One is exogenous pathogenic factors which including the blood-heat, blood dryness, blood stasis, deficiency of liver and kidney, inharmony of impulsive and appointed pulsation, deficiency of blood. The other is exogenous pathogenic factors which including the wind-evil, wind-wetness, wind-heat, wind-cold, wetness-heat, cold-wetness, heat-evil. 4. In Occidental medicine, external applicative medicine, internal medicine, ultraviolet therapy, ultraviolet - external applicative medicine compound therapy and etc. were used the therapy of psoriasis. 5. In Oriental medicine, clean away heat and cooling blood, aliment the blood and moisturize, activating blood and expelling blood stasis, harmonize and invigorate the liver and kidney, invigorate the kidney, aliment the blood and moisturize the skin, aliment the blood and expelling the wind, expelling the wind and wetness, clean away heat and expelling wind, expelling the wind and scatter the cold, clean away heat and expelling the wetness, heat up the meridian and scatter the cold, clean away heat and remove the toxin and etc. were used the method of internal therapy of psoriasis. 6. Until Qing dynasty, wind expelling effective prescriptions like Bangpungtongsungsan, Sopungsan. Supungsunkisan and etc. were used and recently Yanghyelgeupungtang, Hwalhyelgeupungtang, Samultanggagam and etc. were used the internal therapy of psoriasis. 7. In the external therapy of psoriasis, Yuhonggo, Pungyugo, Sekryupiyeongo were used the plaster therapy and Folium Rerillae, Camphora, Fructus, Xanthii, Herba Spirodelae compound prescription were used the cleansing therapy, Okgisan, Chiunsan, Galmyogo, Hobunsan, Muisan, Madugo, Jeyugohengin were used the rubbing skin therapy. Rangdok Radix Aconiti, Bijeonilchoalkwang were used the attaching therapy, the extract of Rhizoma Et Radix Veratri was used the spreading pouder therapy. 8. In the acupuncture therapy of psoriasis, the Jelgol, chok Samni(S36), Kansa(P5), Haegye(S41), Wijung(B40) and etc. were used the acupuncture point, and the angle of helix incision threapy that disinfect and cut the angle of helix and plaster the Semen Glycine and Squama Manitis were used.

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