• Title/Summary/Keyword: Difference Pressure

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Estimation of Physiological Variables for LVAS Control Using an Axial Flow Blood Pump Model (축류혈액펌프 모델을 이용한 좌심실보조장치 제어를 위한 생리학적 변수의 추정)

  • 최성진
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.12
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    • pp.1061-1065
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    • 2002
  • Sensors need to be implanted to obtain necessary information for LVAS (Left Ventricular Assist System) operations. Size of the sensors can prevent them from being implanted in a patient and reliabilities of the sensors are questionable for a long term use. In this wort we utilize a developed pump model to estimate flow and pressure difference across the pump without implanted sensors and present a method to obtain the physiological variables as aorta pressure and left ventricle pressure from the pump model and pulsatility of flow estimate or pressure difference estimate. These estimated variables can be used for LVAS control as an index or indices.

Supplementary Effect of Lentinus Edodes on Serum and Hepatic Lipid Levels in Spontaneously Hypertensive Rat (표고버섯의 급여가 SHR 흰쥐의 혈압 및 혈청 지질 수준에 미치는 영향)

  • Lee Sung Hyeon;Park Hong Ju;Cho So Young;Jeong Hyun Jin
    • Journal of Nutrition and Health
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    • v.37 no.7
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    • pp.509-514
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    • 2004
  • This study was conducted to investigate the supplementary effects of Lentinus edodes on blood pressure and blood lipid levels in the Hypertensive Rat. We supplied 3 kinds of experimental diets (Control; CO, cap of Lentinus edodes; LC, and stipe of Lentinus edodes; LS) to spontaneously hypertensive rats (SHR) for 8 weeks. Diet intake, body weight, organ weights, and serum lipid levels were measured. There was no significant difference in diet intake, and body, liver and epididymal fat pad weights among experimental groups. The levels of systolic and diastolic blood pressure were significantly lower in LC and LS groups than CO group. The concentrations of serum total cholesterol were lower in LC and LS groups than CO group. These results suggested that Lentinus edodes decrease blood pressure levels and serum total cholesterol concentration in the spontaneously hypertensive rats. But these effects of Lentinus edodes didn't show any significant difference between animals fed cap and stipe of this mushroom.

Experimental study on the transfer in pulse tube (맥동관 내부의 열전달에 관한 실험적 연구)

  • 김민규;남관우;정상권;장호일;정은수
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.1
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    • pp.45-50
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    • 2000
  • The present study has been conducted to observe the heat transfer under pulsating pressure and oscillating flow. The experimental apparatus was fabricated to measure the gas temperature, the wall temperature. the pressure and the instantaneous heat flux inside the pulse tube. The measured gas temperature and heat flux must be calibarated to compensate their finite time constant in the oscillating flow conditious. The experiment was performed from 1 Hz to 5 Hz. The phase difference between the instantaneous heat flux and the gas-wall temperature difference was clearly observed. The experimental heat fluxes were compared to the theroretical correlations such as Complex Nusselt Number Model(CNNM) and Variable Coefficient Model(CVM). The heat flux predisted by CNNM was always greater than that of VCM. The experiment confirmed the valisity of the VCM for the instantaneous heat flux under the pulsating pressure and oscillating flow in the warm end of the pulse tube.

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Numerical Study on the Behavior Characteristics of a Screw in Injection Molding Machine (사출기 스크류의 변형거동 특성에 관한 수치해석 연구)

  • 김청균;조승현
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.11 no.5
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    • pp.30-37
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    • 2002
  • Single flighted screw injection technology is the most cost effective method for the production of film, sheet, pipe and the fundamental step in other processes including blow molding and injection molding. The temperature of polymer melts and injection pressure play a very important role in the injection molding machine. Thermal distortion and displacement of a screw by temperature difference and injection pressure difference ratio cause a friction and thermoelastic wear by metal-to-metal contact between the screw and the cylinder. In this paper we analyzed thermal distortions of a screw as functions of temperature distribution and pressure profiles by finite element analysis.

An Study of Pressure Variations in Smoke Control on Protected Escape Routes Using Pressurization (급기가압 제연 시 전실 내 압력변화에 관한 연구)

  • Kim, Hong-Sik;Oh, Dae-Hee
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.247-250
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    • 2008
  • Pressurization is a method of ensuring that protected escape routes(staircases and lobbies) are kept free of smoke for shelterers and fire fighters by raising the air pressure in these spaces above that in the main part of the building. In this study, to estimate a pressurization, the characteristics of pressure difference in a room, a lobby, an air supply shaft at several building elements are investigated with a window, the (a fire) door and a air supply damper so that information about the importance of these experimental parameters can be obtained.

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Internal Wave Computations based on a Discontinuity in Dynamic Pressure (동압 계수의 불연속성을 이용한 내면파의 수치해석)

  • 신상묵;김동훈
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.4
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    • pp.17-29
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    • 2004
  • Internal waves are computed using a ghost fluid method on an unstructured grid. Discontinuities in density and dynamic pressure are captured in one cell without smearing or oscillations along a multimaterial interface. A time-accurate incompressible Navier-Stokes/Euler solver is developed based on a three-point backward difference formula for the physical time marching. Artificial compressibility is introduced with respect to pseudotime and an implicit method is used for the pseudotime iteration. To track evolution of an interface, a level set function is coupled with the governing equations. Roe's flux difference splitting method is used to calculate numerical fluxes of the coupled equations. To get higher order accuracy, dependent variables are reconstructed based on gradients which are calculated using Gauss theorem. For each edge crossing an interface, dynamic pressure is assigned for a ghost node to enforce the continuity of total pressure along the interface. Solitary internal waves are computed and the results are compared with other computational and experimental results.

Comparision of the Pressure Denaturation of Metmyoglobin in $H_2O$ and $D_2O$ ($H_2O$$D_2O$ 에서 메트미오글로빈의 압력에 의한 변성의 비교 연구)

  • Keon Kim
    • Journal of the Korean Chemical Society
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    • v.28 no.1
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    • pp.14-19
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    • 1984
  • The stability difference of metmyoglobin in $H_2O$ and $D_2O$ at pH 5.7 and pH 7.0 toward pressure denaturation is studied. Metmyoglobin is denatured in $D_2O$ at smaller pressure than in $H_2O$. The stability difference in $H_2O$ and $D_2O$ is more pronounced at pH 5.7 than at pH 7. The main reasons for the stability difference in $H_2O$ and $D_2O$are the difference in positive charge due to $H^+$and $D^+$ binding to the protein in $H_2O$ and $D_2O$, and the structural change that accompany deuteration.

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Effect of Cooking Condition on the Eating Quality of Cooked Brown Rice (취반조건이 현미밥의 식미특성에 미치는 영향)

  • 김경애;정난희;전은례
    • Korean journal of food and cookery science
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    • v.11 no.5
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    • pp.527-535
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    • 1995
  • The sensory and instrumental characteristics of different water to brown rice ratio with pressure and electric cookers were examined. The result of sensory evaluation revealed more significant differences in most of taste, texture, appearance, overall eating quality. The difference of sensory characteristics according to the types of cookers and the difference water to brown rice ratio showed the highest preference nonwaxy brown rice 1.4 and waxy brown rice with pressure cooker The instrumental measurement of cooked brown rice using instron showed that the difference between different water to brown rice ratio and pressure cooker. Especially hardness in instrumental characteristics revealed highly significant difference.

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A Study on the Development of a Calf Supporter for Improving Balance Capacity (균형능력 향상을 위한 종아리 서포터 개발에 관한 연구)

  • Hwang, Sunkyu;Park, Jinhee;Kim, Jooyong
    • Journal of Fashion Business
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    • v.25 no.1
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    • pp.39-50
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    • 2021
  • The purpose of this study was to investigate how wearing calf support and applying of electronic muscle simulation(EMS) affected the ability to balance. In this study, the one leg standing test for static balance and the Y balance test for dynamic balance were used to assess balance. At this time, the pressure of the calf support was different to produce two supporters, and a difference between wearing the support before, after, and after applying EMS was evaluated. Seven men in their 20s with healthy bodies were measured five times each with a five-minute break, taking into account muscle fatigue, and the difference between each variable was analyzed through a follow-up test using nonparametric statistical analysis. Studies have shown more difference from supporter B with a more appropriate pressure (mmgh) for increasing balance capability than from supporter A. In addition, it was confirmed that the use of EMS electrostimulation and support before measuring the balance capability resulted in a greater difference. The proper pressure (mmgh) supporters and EMS can increase the ability to balance, and these results can be expected to improve the balance ability of ordinary people in their daily lives.

The effects of lumbar stabilization exercise on respiratory pressure in stroke patients (허리안정화운동이 뇌졸중환자의 호흡압력에 미치는 영향)

  • Park, Shin-Jun;Oh, Dae-Sik
    • Journal of the Korea Convergence Society
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    • v.8 no.9
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    • pp.357-364
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    • 2017
  • The purpose of this study was to investigate the exercise periods changes of the waist stabilization exercise on the inspiratory and expiratory pressure of stroke patients. Thirty-six stroke patients were divided into 17 lumbar stabilization group(LSEG) and 19 general exercise group(GPEG). In both groups, inspiratory and expiratory pressure using a respiratory pressure device was measured over 4 and 8 weeks. At maximal expiratory pressure, LSEG was significantly increased in Before, 4 weeks and 8 weeks according to the period, but there was no significant difference in GPEG in all periods. At maximal inspiratory presusre, there was no significant difference in LSEG between before-4 weeks and 4-8 weeks, but there was a significant increase in Before-8weeks. There was no significant difference in all periods of GPEG group. There was no significant difference in the amount of change between the two groups. In this study, it was found that the lumbar stabilization exercise was effective in improving the expiratory pressure in the stroke patients. If the stroke patient continues to lumbar stabilization exercise, it is also an effective method for inspiratory pressure. Future studies are expected to study individual respiratory muscle measurements after lumbar stabilization exercise.