• 제목/요약/키워드: Superficial Heat

검색결과 43건 처리시간 0.022초

유동층 연소로 내에서 수평전열관의 열전달 특성에 관한 연구 (Heat Transfer Characteristics of a Horizontal Fin Tube in a Fluidized Bed Combustor)

  • 맹민재;정준기;정태용
    • 대한기계학회논문집
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    • 제19권9호
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    • pp.2365-2372
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    • 1995
  • The objective of this study is to get the basic data for the development of fluidized bed combustor. For this purpose, various rake angles(.theta.=20.deg., 25.deg., 30.deg., 35.deg.) of finned tubes and a smooth tube were installed horizontally in the fluidized bed combustor of 410*250mm. The effect of fluidized bed temperature, superficial velocity in bed, size of bed materials, rake angle of finned tubes on the heat transfer coefficient was experimentally investigated. The following results were obtained. (1) Under the fluidized bed temperature(750.deg. C-900.deg. C), and the gas velocity in bed(1.1-2.8m/sec), The highest heat transfer coefficient was measured with the rake angle of finned tubes was .theta.=25.deg. and .theta.=35.deg. for the average fluidized material particle size of 1.22mm and 1.54mm, respectively. Generally, the heat transfer coefficient of finned tubes is 1.4 to 2.4 times larger than that of smooth tubes. (2) The size of bed materials influences the rake angle of finned tubes which can have the highest heat transfer coefficient. As the temperature in bed gets higher, the effect of the rake angle of finned tubes on the heat transfer coefficient becomes greater.

건강한 성인과 성인편마비의 표면열 적용시 사지에서의 동통역치 변화에 관한 연구 (A Study on the Change of Pain Threshold at Limbs Produced by Superficial Heat in Healthy Adult and Adult Hemiplegia)

  • 김중휘;홍도선;이정원
    • 한국전문물리치료학회지
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    • 제3권2호
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    • pp.19-28
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    • 1996
  • The purpose of this study was to asses and compare the effects of superficial heating on the pain threshold at limbs in healthy adult and adult hemiplegia. We used hot pack for superficial heat and applied to healthy adult(n=12) and adult hemiplegia(n=12) on lumbar region. Pain treshold was quantatively measured by an electrical stimulator and measured before hot pack application, immediatly and post 30 minutes after hot pack application on the distal parts of limbs(styloid process of radius, medial malleoulus of tibia). The results were as follows 1) A statically significant defference in pain treshold were not found at limbs of healthy adult and adult hemiplegia that have an affected side and a non-affected side before hot pack application, immediatly and post 30 minutes after hot pack apllication(p>0.05). 2) In comparance of pain threshold of upper and lower limbs in the all subjects, pain threshold was significantly increase at lower limbs(p<0.01). 3) In comparance of pain threshold of limbs between healthy adult and adult hemiplegia, pain threshold was showed a significant defferance at the upper and lower limbs of affected side before hot pack application(p<0.05, p<0.01).

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NH3-Air-C3H8 분위기에서 Nitrocarburisng시 형성된 Compound Layer의 조직제어 (Structural Control of the Compound Layers formed during Nitrocarburising in NH3-Air-C3H8 Atmospheres)

  • 김영희;최광웅
    • 열처리공학회지
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    • 제8권4호
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    • pp.289-301
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    • 1995
  • The effect of Air/$C_3H_8$ gas addition on the compound layer growth of steels nitrocarburised in $NH_3+Air+C_3H_8$ mixed gas atmospheres was investigated. It is considered that amount of residual $NH_3$ was varied according to alternation of Air/$C_3H_8$ mixing ratio and volume content. The compound layer formed from nitrocarburising was composed of ${\varepsilon}-Fe_{2-3}$(C, N) and ${\gamma}^{\prime}-Fe_4$(C, N). According as Air/$C_3H_8$ mixing ratio increased, the superficial content of ${\gamma}^{\prime}-Fe_4$(C, N) within the compound layer was increased, at the same time the growth rate of compound layer and porous layer was increased. In the case of alloy steel at the fixed gas composition, the growth rate of compound layer and porous layer was worse than carbon steel and compound layer phase composition structure primarily consisted of E phase. As the carbon content of materials was increasing in the given gas atmospheres, the growth rate of compound layer and porous layer was increased and the superficial content of ${\varepsilon}-Fe_{2-3}$(C, N) within the compound layer was increased.

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사상체질병증(四象體質病症)과 맥진(脈診)의 상관성(相關性)에 대(對)한 문헌적(文獻的) 고찰(考察) (A Bibliographical Research of the Correlation Among Sasang Constitutional Disease(사상체질병증) and the Pulse Diagnosis(맥진))

  • 김동준;김정렬;김달래
    • 대한약침학회지
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    • 제6권3호
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    • pp.23-37
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    • 2003
  • The purpose of this research was to investigate the correlation Among Sasang Constitutional Disease and Examination of the pulse. I have gone over literatures of mainly ${\ulcorner}$Dongyi Soose Bowon${\lrcorner}$ and the others Oriental Medical book was studied about the Pulse Diagnosis. And then I came to get some conclusion as follows. 1. Soeumin(소음인) the initial-stage symptoms of wulkwang disease(울광증) ; when the Superficial Pulse and the Superficial+ Moderate Pulse is made a diagnosis, Ceongunggyegitang(천궁계지탕) and Gunggyuhyangsosan(궁귀향소산) can be used. 2. Soeumin(소음인) the initial-stage blood disease symptoms of wulkwang disease(울광증) ; when the Minute+deep Pulse is made a diagnosis, Palmulgnnjatang(팔물군자탕) and Guakhyanggeonggisan(곽향정기산) can be used. 3. Soeumin(소음인) the initial-stage symptoms of mangyang disease(망양증) ; when the Yang region Superficial Pulse and the Yin region Weak Pulse is made a diagnosis, Hwanggigyegitang(황기계지탕), Bojungikgitang(보증익기탕) and Sengyangikgitang(승양익기탕) can be used. 4. Soeumin(소음인) the symptoms of taeum disease(태음증) ; when the Minute Pulse and Deep+Thin Pulse is made a diagnosis, Sasang Prescription can be used. 5. Soeumin(소음인) the symptoms of soeum disease(소음증) ; when the Minute+Thin Pulse, Deep Pulse and Thin+Deep+Rapid Pulse is made a diagnosis, Sasang Prescription can be used. 6. Soyangin(소양인) Wind of soyang disease(소양상풍증) ; when the Superficial+Tight Pulse is made a diagnosis, Hungbangpaedogsan(형방패독산) can be used. And when the Deep+Full with strong power Pulse is made a diagnosis, Hyungbangdojeoksan(형방도적산) can be used. 7. Soyangin(소양인) the symptoms of mangyeum disease(망음증) ; when the Superficial+Large+Rapid Pulse and Flood+Large Pulse is made a diagnosis, Hungbangsabaeksan(형방사백산) can be used. And when the Wiry+Thin Pulse is made a diagnosis, Hungbanggiwhangtang(형방지황탕) can be used. 8. Soyangin(소양인) the chest-phrenic fever syndrome(흉격열증) ; when the Superficial Pulse, Flood+Full+Rapid Pulse and Flood+Large Pulse is made a diagnosis, Sasang Prescription can be used. 9. Soyangin(소양인) the after fever syndrome(음허오열증) ; when the Empty+Soft+Rapid Pulse is made a diagnosis, Sasang Prescription can be used. 10. Taeumin(태음인) the upper neck exterior disease caused by Cold(배추표병) ; when the Superficial and Superficial+Tight Pulse is made a diagnosis, Mawhangbalpoytang(마황발표탕) can be used, And when the Superficial and Superficial+Tight with strong power on left hand Pulse is made a diagnosis, Ungdamsan(웅담산) and Handayulsotang(한다열소탕) can be used. 11. Taeumin(태음인) the Coldness syndrome in esophagus(위완한증) ; when the Superficial+Tight Pulse with weak power on left hand Pulse is made a diagnosis, Taeumjowetang(태음조위탕) can be used. 12. Taeumin(태음인) the Dryness-Heat syndrome(조열증) ; when the Flood+Large Pulse, Long Pulse and Long+Large Pulse is made a diagnosis, Galgeunhaegitang(갈근해기탕) can be used. And when the Tight+Full+Rapid Pulse with deep region is made a diagnosis, Yuldahansotang(열다한소탕) can be used. And when the Superficial+Slippery Pulse is made a diagnosis, Chungsimyunjatang(청심연자탕) can be used. 13. Taeumin(태음인) the symptoms of Yin-blood Exhaustion(음혈모갈증) ; when the Superficial with weak power Pulse is made a diagnosis, Nokyongdaebotang(녹용대보탕) can be used. And when the Deep with weak power Pulse is made a diagnosis, Gongjinheukwondan(공진흑원단) can be used. 14. Taeyangin(태양인) a slight Lumbar vertebrae disease(외감경증) ; when the Superficial+Hollow Pulse is made a diagnosis, Gunshitang(건시탕) can be used. 15. Taeyangin(태양인) the Generalized and Fatigue syndrome(해역증) ; when the Moderate+Choppy Pulse with left hand chi region(척맥) is made a diagnosis, Ogapijangchuktang(오가피장척탕) can be used. 16. Taeyangin(태양인) a slight Small Intestine disease(내촉경증)

Comparison of Heat Transfer in Both the Riser and Downcomer of a Circulating Fluidized Bed

  • Hassanein, Soubhi A.;Dahab, O.M.
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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    • pp.24-32
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    • 2004
  • The characteristics of heat transfer from horizontal cylinder immersed in both a riser and downcomer of a circulating fluidized beds were investigated experimentally under different values of solids mass flux, superficial air velocity, particle size diameter, and different bed materials. The test results indicated that local heat transfer coefficients in both riser and downcomer are strongly influenced by angular position, and mass flux, as well as by particle size and bed materials. The local heat transfer coefficients around a circumference of the cylinder inside a riser and downcomer of a CFB exhibited a general tendency to increase with decreasing particle size and increasing solids mass flux and vary with different bed materials. Also the averaged heat transfer coefficient calculated from local heat transfer coefficient exhibited the same trend as a local i.e increase with decrease particle size and increasing solids mass flux and vary with varying bed materials. The general trend for a riser local heat transfer coefficient is decrease with increase angle until ${\Phi}$ = 0.5-0.6 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Also the general trend for a local heat transfer coefficient in downcomer is to increase with increase the angle until ${\Phi}$= ${\theta}/{\Pi}$ = 0.3-0.5 (Where at angle =180$^{\circ}$ ${\Phi}$ =1). Comparison the results of the heat transfer in the riser and downcomer of a circulating fluidized beds shows that they have approximately the same trend but the values of heat transfer coefficients in riser is higher than in downcomer.

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Heat Transfer Correlations for Air-Water Two-Phase Flow of Different Flow Patterns In a Horizontal Pipe

  • Kim, Dongwoo
    • Journal of Mechanical Science and Technology
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    • 제15권12호
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    • pp.1711-1727
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    • 2001
  • Heat transfer coefficient were measured and new correlations were developed for two-phase heat transfer in a horizontal pipe for different patterns. Flow patterns were observed in a transparent circular pipe (2.54 cm I. D. and L/D=96) using an air/water mixture. Visual identification of the flow patterns was supplemented with photographic data and the results were plotted on the flow regime map proposed by Taitel and Dukler and agreed quite well with each other. A two-phase heat transfer experimental setup was built for this study and a total of 150 two-phase heat transfer data with different flow patterns were obtained under a uniform wall heat flux boundary condition. For these data, the superficial Reynolds number ranged from 640 to 35,500 for the liquid and from 540 to 21,200 for the gas. Our previously developed robust two-phase heat transfer correlation for a vertical pipe with modified constants predicted the horizontal pipe air-water heat transfer experimental data with good accuracy. Overall the proposed correlations predicted the data with a mean deviation of 1.0% and an rms deviation of 12%.

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2상류의 장거리 수송시 효율적인 열관리에 관한 실험적 연구 (Experimental Study on the Efficient Control of Heat of Lc Distance Transport for Two- Phase Fluid)

  • 김재호;김재근;오율권;차경옥
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집E
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    • pp.119-124
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    • 2001
  • This experimental study was conducted to figure out the characteristics of convective heat transfer non boiling vertical downward flow with polymer additives. This experiment was studied in diameter, 800mm heating length and $1{\times}10^5 W/m^2$ heat flux. The polymer concentration ranged 0ppm to 500ppm with corresponding from superficial liquid velocity 1.25m/s to 2.5m/s in non bo vertical up and downward flow. Experimental results show that the characteristics of convective transfer was a strong function of polymer concentration and it has decreased with increasing polymer concentration in non boiling up and vertical downward flow.

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미소중력하의 기액이상류의 유동양식 (Flow Patterns of Gas-Liquid Two-phase Flow under Microgravity)

  • 최부홍
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권3호
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    • pp.460-465
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    • 2003
  • Microgravity experiments were conducted to determine the effect of liquid and gas superficial velocities on flow behaviors. Flow behaviors observed under microgravity conditions can be classified into five flow patterns: bubble. Taylor bubble, slug, semi-annular and annular flows. Transition boundary between four flow patterns could be determined by drift-flux model. It was also found that the effect of gravity and pipe inclination on flow pattern transition was not significant in the inertia dominant region.

하루 중 시간변화(時間變化)에 따른 한출(汗出)의 기전(機轉)에 대한 연구(硏究) (A Study on Perspirations(汗出) in Daily Time Cycle)

  • 유정아;정창현
    • 대한한의학원전학회지
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    • 제22권3호
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    • pp.271-289
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    • 2009
  • This thesis intend to help the eastern medical doctor to understand body condition from interpretation of perspirations(汗出) in daily time cycle. The conclusion is followed. 1. In most Eastern Medical classic and clinic literatures, the time of fever and perspirations are described as a result of disease's position at human body. Following this description, in daytime the perspirations must come from the Gi phase and night time the perspirations must come from the blood phase. Because in daytime the skin pores are opening and the defensive Gi is going out to the superficial portion of the body. In night time the skin pores are shutting and the defensive Gi is going in to the five solid organs. So a sweat in daytime comes out from the Gi phase and superficial portion of the body. And in night time comes out from the blood phase and five solid organs. But in recent real clinic cases, in daytime, there are so many perspirations from the five solid organs. Comparatively, the perspirations from the superficial portion of body are very little. And in same daytime perspirations, when the heat pathogens mixed with moist, the symptom revelation time delay to the afternoon. Therefore it can be concluded that the time of perspirations are combination of disease's Gi or blood phase and characteristics of pathogens. The position of disease at human body cannot simply judge the symptom revelation time. 2. The exchange of climate following time cycle of a day effect to the condition of human body. At same time it activates or not activates the pathogens in human body. So we can consider the kinds and characteristics of pathogens by distinguishing the symptom revelation time. In general differentiation of syndromes[辨證] pathogen's kinds and location are generally judged. By understanding the characteristics of pathogen, doctor can devise more correct and delicate prescription.

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한국표준질병 사인분류에 따른 위염(胃炎)의 한의학적 변증 연구 (Study on Syndrome Differentiation of Gastritis by Korean Standard Classification of Dsease and Cause of Death)

  • 박미선;김영목
    • 동의생리병리학회지
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    • 제31권5호
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    • pp.255-263
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    • 2017
  • This article is for understanding relations between the classifications of gastritis and syndrome differentiation types of Korean Medicine through research on syndrome differentiations of clinically applied gastritis and literature of Korean Medicine. Clinical papers were searched in China Academic Journals(CAJ) of China National Knowledge Infrastructure(CNKI) from 1995 to 2015. Conclusions are as follows. First, disease mechanism of chronic gastritis are qi stagnation, damp stagnation, heat obstruction, blood stasis obstruction, yin damage, damage to collaterals with healthy qi deficiency and pathogenic qi. And qi movement stagnation is shown through the status of chronic gastritis. Second, chronic superficial gastritis belongs to qi aspect syndrome and mainly pathogen excess syndrome. And the key mechanisms are congestion and disharmony of stomach qi sometimes combined with liver depression, food accumulation and dampness-heat. Third, chronic atrophic gastritis belongs to qi-blood syndrome and deficiency-excess complex syndrome with the root of spleen qi deficiency and stomach yin deficiency and the tip of blood stasis, qi stagnation. And key mechanism is damage to collaterals with healthy qi deficiency and toxin-blood stasis. Forth, pathogen excess syndromes are shown at the early stage of chronic gastritis and healthy qi deficiency syndromes after the middle stage. Qi deficiency is shown at the beginning of the disease and yin deficiency at the late stage. And qi deficiency is related with superficial gastritis and yin deficiency with atrophic gastritis.