• 제목/요약/키워드: Heat Indicator

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An investigation on heat transfer effects of two dimensional plane jet attaching offseted obliqued wall (단이 진 경사벽면에 부착되는 2차원 평면제트의 열전달 효과에 관한 연구)

  • Yun, Sun-Hyeon;Lee, Dae-Hui;Sim, Jae-Gyeong;Song, Heung-Bok
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1314-1325
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    • 1997
  • Experiments have been conducted to determine the flow and heat transfer characteristics for a two-dimensional turbulent wall attaching offset jet at different oblique angles to a flat surface. The distributions of the wall static pressure coefficient and time-averaged reattachment position for various offset ratios and oblique angles have been measured. The local Nusselt number distributions on the plate surface were also measured using liquid crystal as a temperature indicator. The new hue-capturing technique utilizing a true color image processing system was used to accurately determine the temperature of the liquid crystal. The experiments were carried out at Reynolds number, Re (based on D) of from 7300 to 21,300 with offset ratio, H/D from 2.5 to 10, and oblique angle, .alpha. from 0 deg. to 400 deg..

Study of the Specific Indicators Calculation of Fire-Heat Pattern Identification and Yin Deficiency Pattern Identification in Stroke (중풍 화열 변증과 음허 변증을 구분하는 특정 지표 산출에 대한 연구)

  • Kang, Baek-Gyu;Kang, Byeong-Kab;Lee, Jung-Sup;Han, Deok-Jin;Nam, Sang-Kyu;Shin, Sun-Ho;Moon, Byung-Soon;Lee, In
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.6
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    • pp.1368-1373
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    • 2008
  • This study was done to calculate the specific indicators of Fire-Heat Pattern Identification and Yin Deficiency Pattern Identification settled by tentative Korean Standard Differentiation of the Symptoms and Signs for Stroke. The subjects were 764 hospitalized patients with stroke, and a list of registry was made for each of them. Frequency and Correlations among Fire-Heat and Yin Deficiency indicators were studied. Fire-Heat pattern group included 175 patients out of 764, Yin Deficiency pattern group included 103 patients out of 764. Among the indicators of Fire-Heat pattern, those, in order of highest frequency, were 'heat vexation and aversion to heat', 'reddened complexion', 'thirst'. Among the indicators of Yin Deficiency pattern, those, in order of highest frequency, were 'dry mouth', 'red tongue', 'fine and rapid pulse'. Among the Fire-Heat pattern indicators, 'yellow fur' and 'thirst', 'heat vexation in the chest' and 'vexation and insomnia' showed most significant correlation. Among the Yin Deficiency pattern indicators, 'aphtha or tongue sore' and 'heat in the palms and soles', 'red tongue' and 'dry fur' showed most significant correlation. 'Reddened complexion', 'dry eyes', 'surging and parid pulse', 'heat vexation and aversion to heat' are classify between Fire-Heat pattern and Yin Deficiency pattern. 'Surging and parid pulse', 'Reddened complexion' are mostly representative of Fire-Heat pattern and 'fine and rapid pulse' are mostly representative of Yin Deficiency pattern.

A Study on Association of DSOM Symptom Scores for Women infertility in Oriental Medicine (한방진단시스템을 이용한 여성불임(女性不姙)의 한의학적 인자(因子) 연구)

  • Cho, Hye-Sook;Um, Yun-Kyung;Yu, Ju-Hee;Kang, Jong-Geun;Kim, Kyu-Kon;Lee, In-Sun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.1
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    • pp.214-238
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    • 2007
  • Purpose : We have carried out this study to investigate association of DSOM scores and women infertility in oriental medicine for systematization diagnosis and treatment of women infertility. Methods : We analyzed the results of medical records for 151 patients who were diagnosed as women infertility. We investigated the possession of symptom index of women infertility, recognition association of DSOM. Results : 1. In comparison with 151 clinical trial's data. deficiency of Yin(陰虛), coldness(寒), spleen(脾) are associated positively and deficiency of Yang(陽虛), phlegm(痰) are associated negatively. 2. In pathogenesis(病機) indicator of average, cold inside the body is associated positively and diarrhea, kidney are associated negatively. 3. In pathogenesis five score-point of value, Heat(熱), kidney(腎) are associated negatively. 4. In pathogenesis(病機) indicator. constipation(便秘) is associated positively and hardness of lower abdomen, tingly weakness of lower back and knee question are associated negatively. 5. In 140 questions, nine questions are associated positively and ten question are associated negatively.

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The Impact of High Apparent Temperature on the Increase of Summertime Disease-related Mortality in Seoul: 1991-2000 (높은 체감온도가 서울의 여름철 질병 사망자 증가에 미치는 영향, 1991-2000)

  • Choi, Gwang-Yong;Choi, Jong-Nam;Kwon, Ho-Jang
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.3
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    • pp.283-290
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    • 2005
  • Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

Ductility Degradation Assessment of Baffle Former Assembly Considering the Stress Triaxiality Effect (응력 삼축성을 고려한 원자로 내부구조물 배플포머 집합체의 연성저하 평가)

  • Kim, Jong-Sung;Park, Jeong Soon;Kang, Sung-Sik
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.12 no.2
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    • pp.50-57
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    • 2016
  • The study presents structural integrity assessment of ductility degradation of a baffle former assembly by performing finite element analysis considering real loading conditions and stress triaxiality. Variations of fracture strain curves of type 304 austenitic stainless steel with stress triaxiality are derived based on the previous study results. Temperature distributions during normal operation such as heat-up, steady state, and cool-down are calculated via finite element temperature analysis considering gamma heating and heat convection with reactor coolant. Variations of stress and strain state during long operation period are also calculated by performing sequentially coupled temperature-stress analysis. Fracture strain is derived by using the fracture curve and the stress triaxility. Finally, variations of ductility degradation damage indicator with the fracture strain and the equivalent inelastic strain are investigated. It is found that maximum value of the ductility degradation damage index continuously increases and becomes 0.4877 at 40 EFPYs. Also, the maximum value occurs at top and middle inner parts of the baffle former assembly before and after 20 EFPYs, respectively.

$CO_2^*$ Background Effect on $OH^*$ and $CH^*$ Chemiluminescence Intensities in a Gas Turbine Combustor (가스터빈 연소기에서 $CO_2^*$ 배경 강도가 $OH^*$$CH^*$ 화학 발광 강도에 미치는 영향)

  • Kim, Dae-Sik;Lee, Jong-Guen
    • Journal of the Korean Society of Combustion
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    • v.15 no.4
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    • pp.37-42
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    • 2010
  • The measurement of heat release rate is of great importance in the study of thermo-acoustic instability occurring in lean premixed combustion and the chemiluminescence emission has been used as an indicator of heat release in combustion instability studies primarily for its relative simplicity. This paper presents results of experimental study of flame chemiluminescence from an atmospheric, swirl-stabilized, turbulent lean premixed flame with a main emphasis on the effect of $CO_2^*$ background level in the $CH^*$ and $OH^*$ band. The test results show that the effect of $CO_2^*$ level in the $CH^*$ band is greater than that in the $OH^*$ band. Also, the background to peak ratio for both $CH^*$ and $OH^*$ bands can be expressed as a function of equivalence ratio, almost regardless of a change in the inlet velocity.

The Characteristics, Detection and Control of Bacteriophage in Fermented Dairy Products (발효유제품에서 박테리오파지의 특성, 검출과 제어)

  • Ahn, Sung-Il;Azzouny, Rehab A.;Huyen, Tran Thi Thanh;Kwak, Hae-Soo
    • Food Science of Animal Resources
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    • v.29 no.1
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    • pp.1-14
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    • 2009
  • This study was to review the classification, detection and control of bacteriophage in fermented dairy products. Bacteriophage has lytic and/or lysogenic life cycles. Epidemiologically speaking, detected major phages are c2, 936 and p335. Among them p335 has been the largest concern in dairy industry. Traditionally, various analytical technologies, such as spot, starter activity, indicator test, ATP measurement and conductimetric analysis, have been used for the phage detection. In recent years, advanced methods such as flow cytometric method, petrifilm, enzyme linked immunosorbent assay (ELISA) and multiflex PCR diagnostic kit have been deveoloped. The phage contamination has been controlled by using heat, high-pressure treatment, and the combinations of heat and pressure, and/or chemical. Also some starter cultures with phage-resistant character have been developed to minimize the concentration of phages in dairy product. Bacteriophage inhibition media such as calcium medium was also mentioned. To prevent the contamination of bacteriophage in dairy industry, further researches on the detection and control of phage, and phage resistant starters are necessary in the future.

Effect of Non-Uniform Mixture on Cycle Fluctuation of Multi-Cylinder Spark Ignition Engine(I) (다기통 전기점화기관의 혼합기 불균일화가 사이클 변동에 미치는 영향 (I))

  • 송재학;이용길;박경석;양옥룡
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.9
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    • pp.1736-1743
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    • 1992
  • The combustion in the cylinder of spark ignition engine is completed after the delayed time that the liquid film fuel is vapourized as flowing into the combustion chamber. It is necessary to enhance the homogeneity of mixture and the combustion phenomenon in order to improve the heat efficiency and the emission characteristics of spark ignition engine. The main purpose of this paper is to manufacture a combustion analyzing system and examine closely the influence of non-uniformity due to the liquid film fuel flowing in the intake manifold on the combustion characteristics by using a 4 stroke multi- cylinder spark ignition engine. Moreover, with each cylinder, the interpretation of combustion characteristics by indicator diagram and the concentration of exhaust gas were investigated.

The onset of extreme fire behaviour in a mine drift

  • Hansen, Rickard
    • Geosystem Engineering
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    • v.21 no.5
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    • pp.282-290
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    • 2018
  • The onset of extreme fire behaviour in a mine drift with longitudinal ventilation was analysed. A fire in a mine drift with continuous fuel load, involving several separate fires may lead to flames tilted horizontally and filling up the entire cross section. This will lead to earlier ignition, higher fire growth rate, higher fire spread rate and a severe fire behaviour. The focus has been on what changes take place at the onset and signs of the impending phenomenon. It was found that the fire gas temperature at the ceiling level provided a poor indicator. At the downstream far-field region of the fire, the sudden temperature increase at the lowest levels of the cross section and the sudden increase in flow velocities would provide signs of extreme fire behaviour. The corresponding full-scale heat release rates of the experiments at the onset of extreme fire behaviour were found to be very high for mining applications but not necessarily for tunnel fires. The heat release rate threshold for a mine drift with smaller cross-sectional dimensions would decrease considerably, increasing the likelihood of occurrence. The distance between the fuel items will play an important role during the initiation of horizontal flames.

RELAP5 Analysis of the Loss-of-RHR Accident during the Mid-Loop Operation of Yonggwang Nuclear Units 3/4

  • J. J. Jeong;Kim, W. S.;Kim, K. D.;W. P. Chang
    • Proceedings of the Korean Nuclear Society Conference
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    • 1995.10a
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    • pp.403-410
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    • 1995
  • A loss of the residual heat removal (RHR) accident during mid-loop operation of Yong-gwang Nuclear Units 3/4 was analyzed using the RELAP5/MOD3.1.2 code. In this work the following assumptions are used; (i) initially the reactor coolant system (RCS) above the hot leg center line is filled with nitrogen gas, (ii) two 3/4-inch diameter vent valves on the reactor vessel head and the top of pressurizer in the reactor coolant system are always open, and a level indicator is connected to the RMR suction line, (iii) the two steam generators are in wet layup status and the steam generator atmospheric dump valve assemblies are removed so that the secondary side pressure remains at nearly atmospheric condition throughout the accident, and (iv) the loss of RHR is presumed to occur at 48 hours after reactor shutdown. Findings from the RELAP5 calculations are (i) the core boiling begins at ∼5 min, (ii) the peak RCS pressure is ∼3.0 bar, which implies a possibility of temporary seal break, (iii) ∼94 % of the decay heat is removed by reflux condensation in the steam generator U-tubes in spite of the presence of noncondensable gas, (iv) the core uncovery time is evaluated to be 7.2 hours. Significant mass errors were observed in the calculations.

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