• Title/Summary/Keyword: total pressure

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A Study on the Performance Analysis of Diesel Engine Supercharged by Exhaust Gas Thrbine (배기가스 터빈과급 디젤기관의 성능해석에 관한 연구)

  • 안진근
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.4
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    • pp.421-429
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    • 1997
  • This study is theoretically examined the influences on the performance of diesel engine super¬charged by exhaust gas turbine with the change of excess air factor, admission ratio, total efficien¬cy of turbine and compressor, scavenging pressure ratio, and scavenging temperature. In this study, all calculations are carried out by computer, and the theoretical engine performance is com¬pared with the actual engine performance which is offered from engine manufacturer. Following results are acquired by this study. The mean effective pressure is increased with decrease of excess air factor or increase of scavenging pressure ratio. As the admission ratio or total efficiency of tur¬bine is increased, the mean effective pressure is increased but the specific fuel consumption is decreased. Mean calculation error compared with the actual engine performance is under 5 per¬cents, therefore, this calculation method can be used in the design of diesel engine.

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The Effect of Dietary Hizikia Fusiforme on the Reduction of Blood Pressure and Total Cholesterol in Jeju Women Divers (제주 해녀의 식이성 톳 섭취를 통한 혈압 및 총콜레스테롤 감소 효과)

  • Lee, Han Young;Kim, Jong Du
    • Journal of Digital Convergence
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    • v.15 no.5
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    • pp.471-478
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    • 2017
  • The purpose of this study was to investigate the changes of blood pressure and total cholesterol after eating Hizikia fusiforme for 8 weeks with 100g of rice per day. As a result, the systolic blood pressure of the group ingesting Hizikia fusiforme significantly decreased. Second, diastolic blood pressure decreased significantly in both groups, but there was no difference between groups. Third, the systolic - diastolic blood pressure difference showed a significant decrease in the group of ingestion of Hizikia fusiforme, while that of the group without intake of Hizikia fusiforme increased. Fourth, total cholesterol decreased significantly in the group consuming Hizikia fusiforme but increased in the group not consuming Hizikia fusiforme. The above results indicate that total intake of 100 g of dried Hizikia fusiforme per day was effective in decreasing total cholesterol and reducing systolic blood pressure.

Correlations between Weight, Body Mass Index(BMI) and Risk Factors of Coronary Artery Disease in Men and Women in their Forties and Fifties (40,50대 남녀별 체중, BMI와 관상동맥질환 위험인자 간의 상관 정도 비교)

  • 김희승;정혜선;한경실
    • Journal of Korean Academy of Nursing
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    • v.28 no.1
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    • pp.184-192
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    • 1998
  • This study was done to examine the correlations between weight, BMI and risk factors of coronary heart disease in men and women in their forties and fifties. The subjects were 412 adults. who had regular health examinations between January and December of 1996 at S-Hospital in Seoul. The data were analyzed using ANOVA, Scheffe test, and Pearson correlation coefficient. The results are as follows : 1. The men between 50 and 59 years of age had higher levels for BMI, weight, systolic blood pressure, diastolic blood pressure, total cholesterol. LDL-cholesterol, triglyceride, fasting blood sugar, plasminogen activator-1, and hemoglobin A,C than the group of women in their forties. Yet. HDL-cholesterol was lower than in the former group. 2. In the group of men in their forties, weight was significantly correlated to diastolic blood pressure(r=.22), LDL-cholesterol(r=.20), plasminogen activator-inhibitor-1(r=.35) HDL-cholesterol(r=-.19). Their BMI was significantly correlted to systolic blood pressure(r=.27), diastolic blood pressure (r=.33), total cholesterol(r=.23), LDL-cholesterol (r=.26), plasminogen activator-1(r=.36) and HDL-cholesterol(r=-.25). 3. As for the group of women in their forties weight was significantly correlated to systolic blood pressure(r=.20), diastolic blood pressure(r=.22), triglyceride(r=.32) , plasminogen activator inhibitor-1 (r=.30) and HDL-cholesterol(r= -.37). Their BMI was significantly correlated to diastolic blood pressure (r=.25) triglyceride(r=.47), plasminogen activator-1 (r=.35), fibrinogen(r=.27) and HDL-cholesterol(r=-.47). 4. In the group of men in their fifties. weight was significantly correlated to total cholesterol (r=32), LDL-cholesterol(r=.29). plasminogen activator inhibitor-1(r=.26). Their BMI was significantly correlated to systolic blood pressure(r=.24), diastolic blood pressure (r=.22), total cholesterol (r=.34), LDL-cholesterol (r=.32), and plasminogen activator-1(r=.25). 5. In the group of women in their fifties, weight was significantly correlated to diastolic blood pressure(r=.33), total cholesterol(r=.21), LDL-cholesterol(r=.20), plasminogen activator inhibitor-1 (r=.43) and HDL-cholesterol(r=-.21). Their BMI was significantly correlated to systolic blood pressure(r=.25), diastolic blood pressure(r=.40), total cholesterol(r=.24), LDL-cholesterol(r=.24), triglyceride(r=22), and HDL-cholesterol (r=-.30). The above findings indicate that the BMI was more predictive than weight as a risk factor for coronary artery disease for men and women in their forties and fifties.

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A New Correlation on Pressure Drop in Horizontal Multi Channels (수평 다채널에서의 압력강하에 관한 새로운 상관식)

  • CHOI, Yong-Seok;LIM, Tae-Woo;YOU, Sam-Sang;KIM, Hwan-Seong
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.5
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    • pp.1273-1279
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    • 2016
  • Flow boiling pressure drop in multi channels was experimently investigated. The multi channel has a width and depth of 0.45 and 0.2mm respectively, and comprises 15 parallel channels. The measured total pressure drop is expressed by the sum of the frictional pressure drop and acceleration pressure drop. In order to predict the total pressure drop, it is required to obtain the correct frictional pressure drop. The existing correlations to predict the frictional pressure were compared with measured frictional pressure drop. The new correlation was developed in the form of the Chisholm correlation. It was related to Chisholm Constant B as a function of Martinelli parameter. The new correlation predicted the experimental data within a mean absolute error of 5.5%.

Effects of the Inlet Boundary Layer Thickness on the Flow in an Axial Compressor(II) - Loss Mechanism - (입구 경계층 두께가 축류 압축기 내부 유동에 미치는 영향 (II) - 손실구조 -)

  • Choi, Min-Suk;Park, Jun-Young;Baek, Je-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.8 s.239
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    • pp.956-962
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    • 2005
  • A three-dimensional computation was conducted to make a study about effects of the inlet boundary layer thickness on the total pressure loss in a low-speed axial compressor operating at the design condition ($\phi=85\%$) and near stall condition($\phi=65\%$). Differences of the tip leakage flow and hub corner-stall induced by the inlet boundary layer thickness enable the loss distribution of total pressure along the span to be altered. At design condition, total pressure losses for two different inlet boundary layers are almost alike in the core flow region but the larger loss is generated at both hub and tip when the inlet boundary layer is thin. At the near stall condition, however, total pressure loss fer the thick inlet boundary layer is found to be greater than that for the thin inlet boundary layer on most of the span except the region near hub and casing. Total pressure loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss using Denton's loss model, and effects of the inlet boundary layer thickness on the loss structure are analyzed in detail.

Kinematic characteristics of grip force in patients with cervical spondylosis

  • Lee, Bumsuk;Noguchi, Naoto;Kakiage, Daiki;Yamazaki, Tsuneo
    • Physical Therapy Rehabilitation Science
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    • v.4 no.2
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    • pp.61-65
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    • 2015
  • Objective: The aim of this study was to objectively evaluate sensory disturbance in cervical spondylosis using grip force and investigate the relationship between the grip force and upper extremity function. Design: Cross-sectional study. Methods: Eleven cervical spondylosis patients with paresthesia conducted grip and lift tasks using a precision grip with the tips of the thumb and index finger on either side. The sum of the grip force used during the first four seconds was calculated and defined as the total grip force. The cutaneous pressure threshold of the fingers, the pinch power, the grip power and three subtests of the Simple Test for Evaluating Hand Function (STEF) were also assessed. Correlations between the total grip force and cutaneous pressure threshold, pinch power, grip power, and STEF subtest times were evaluated. Results: We found that the total grip force correlated with the cutaneous pressure threshold (p<0.05). Moreover, the total grip force of the dominant thumb correlated with the results of the three STEF subtests (p<0.05). There were no significant correlations between the total grip force and pinch/grip powers. Conclusions: We found that the total grip force correlated with cutaneous pressure threshold and upper extremity function. The results suggest that the total grip force could serve as an objective index for evaluating paresthesia in cervical spondylosis patients, and that the impaired ability of the upper extremity function is related to grip force coordination.

Effect of Chin Gan Sik Pung Tang on Blood Pressure and induced Hypercholesteremic Rabbit (진간식풍탕(鎭肝熄風湯)이 가토(家兎)의 혈압(血壓) 및 혈청(血淸) Total Cholesterol에 미치는 영향(影響))

  • Kim, Hee-Joon;Yim, Jea-Hoon
    • The Journal of Internal Korean Medicine
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    • v.11 no.1
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    • pp.109-120
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    • 1990
  • In order to investigate the therapeutic effects on blood pressure and hyper cholesteremia, aqueous extract of Chin Gan Sik Pung Tang were studied. The result of the total cholesterol contents in serum and blood pressure of each group were as follows, 1. The aqueous extract of Chin Gan Sik Pung Tang inhibited increased Total cholesterol in serum of rabbits administrated with cholesterol rich diet. 2. Blood pressure manifested gradual response by the fall of 4, 3, 9.2, 19.9 percent in proportion to the administration of 10, 30, 100 mg/kg of Chin Gan Sik pung Tang, respectively 3. Administration of Chin Gan Sik Pung Tang to the rabbit pretreated with Vagotomy, Atropine and Regitine did not show any significant difference in the blood pressure, compare with that of the control group. 4. Administration of Chin Gan Sik Pung Tang to the rabbit pretreated with propranolol show significant difference in the blood pressure, compare with that of the control group. From the above results, it is suggested that Chin Gam Sik Pung Tang has the action on adrenergic ${\beta}-receptor$ and can he used therapeutic effect on the hypertension, and inhibit the increase of Total Cholesterol contents in serum.

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Total pressure dependence of YBCO films in MOD method (MOD 공정에 의해 제조된 YBCO 박막의 압력 의존성)

  • Yoo, Jai-Moo;Chung, Kook-Chae;Ko, Jae-Woong;Kim, Young-Kuk;Wang, Xiao Lin;Dou, Shi Xue
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.1
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    • pp.5-8
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    • 2006
  • The growth properties of MOD-YBCO films were investigated. To enhance the growth rate of YBCO layer and inhibit the build-up of HF gas during the annealing process in TFA-MOD for YBCO coated conductors the method of low pressure annealing was employed. Total pressure was changed from 700Torr to 1Torr and its effect on growth of YBCO films was compared with atmospheric one. The lower Pressure was effective to control of the pore size in MOD method . Surface morphology of YBCO films processed at low total pres sure was rough and composed of random YBCO (103) grains. But large pores, usually observed at atmospheric process in MOD disappeared and also the number of pores was reduced at low pressure annealing. Also discussed ate the effects of Fluorine-free Y and Cu precursor solution on the development of microstructure. Dense surface me phology and with less and small pores can be provided through controlling Fluorine content.

Experimental Investigation for the Characteristics of Energy Separation of a Vortex Tube at Various Inlet and outlet Pressure Conditions (입.출구의 압력조건에 따른 보텍스 튜브의 에너지분리 특성에 관한 실험적 고찰)

  • 유갑종;김정수;최인수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.11
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    • pp.1149-1155
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    • 2001
  • The experimental investigation on energy separation in a vortex tube has been carried out to sow the effect of inlet and outlet pressures with various working fluids(air,$O_2,\;and\; CO_2$). Those outlet pressure means cold outlet and hot outlet pressure which were set equally. The results showed that the total enthalpy variation became a maximum when the mass flow rate at the cold outlet was a half of the total mass flow rate in the vortex tube (y=0.5). The total enthalpy variation was quite affected by the pressure difference between the inlet and outlet of vortex tube when the ratio of the inlet pressure to the cold outlet pressure remained constant. Although specific enthalpy differences between the inlet and the outlet (both cold and hot outlet) did not noticeably vary with the pressure difference, the specific enthalpy difference between the inlet and cold outlet was dominantly affected by physical properties of working gases.

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Experimental Study on the Behavior of Stall Cell in an Axial Flow Fan (축류송풍기의 실속셀 거동에 관한 실험적 연구)

  • Shin You Hwan;Kim Kwang Ho;Kang Chang Sik
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.643-646
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    • 2002
  • Experimental study was conducted to reveal the flow mechanism under rotating stall in an axial flow fan. For this study unsteady pressure was measured using high frequency pressure transducers mounted on the casing wall of rotor passage and total pressure fields were measured at the rotor upstream and downstream. The measured pressure signal was analyzed by Wavelet Transform and Double Phase Locked Averaging Technique. From the result of unsteady pressure field of the casing wall, one period of rotating stall was divided into three zones and the flow characteristics on each zone were described in detail. The pressure field was also analyzed in terms of the pressure distribution along pressure side and suction side of blade tip. From the result of total pressure fields at inlet and outlet of the rotor, the useful information on the characteristics of the stall cell in radial direction was provided.

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