• 제목/요약/키워드: Energy Parameters

검색결과 5,826건 처리시간 0.042초

성인의 영양소 섭취상태 및 체위와 혈액내 지방수준과의 상관관계에 관한 연구 (The effect of dietary intake and anthropometric parameters on the plasma lipid level)

  • 이경애
    • 대한가정학회지
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    • 제33권6호
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    • pp.89-97
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    • 1995
  • This study was undertaken to examine the correlations between dietary intakes or anthropometric parameters and the plasma lipid level. measurements of dali nutrients intake, body weight, height, body bass index, skinfold thickness, blood pressure, plasma total lipid, triglyceride and cholesterol were made to each of 124 healthy adult(25-59yrs) : 56 males and 65 females. The mean energy and nutrients intake, anthropometric parameters and plasma lipid levels were all in normal range. In females, the fat and protein intake, the amount and percents to total energy intake, had positive association with the plasma total lipid, but the energy percent from carbohydrate intake was correlated negatively. And body mass index positively correlated with plasma total lipid level, in male and female, Therefore we could postulated the dietary fat intake and body mass index affected to plasma lipid levels in normal conditions of healthy adult.

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확장표면을 적용한 액체식 제습시스템의 성능특성에 관한 연구 (Performance characterization of liquid desiccant system with extended surface)

  • 장영수;송귀은;이대영
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.639-644
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    • 2009
  • This study presents the new idea of liquid desiccant system with extended surface to reduce the system size. The extended surface is inserted between vertical cooling/heating tubes to increase the mass transfer area, and the liquid desiccant flows through the tube wall and the extended surface. Mathematical models for heat and mass transfer between liquid desiccant and air stream at tube wall and extended surface are provided. Dimensionless design parameters governing heat and mass transfer phenomena around the tube and the extended surface are identifier, and dimensionless operating parameters depicting system operating condition including flow rate ratio between dehumidification/regeneration processes, and mass flow rate ratio between air stream and liquid desiccant are explained. The effects of the parameters on system performance are summarized.

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시뮬레이션에 의한 SF6-He 혼합기체에서 전자에너지 분포함수 (Electron Energy Distribution Function in SF6-He Gas by Simulation)

  • 김상남
    • 전기학회논문지P
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    • 제63권1호
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    • pp.19-23
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    • 2014
  • This paper describes the electron transport characteristics in $SF_6$-He gas calculated E/N values 0.1~700[Td] by the Monte Carlo simulation and Boltzmann equation method using a set of electron collision cross sections determined by the authors and the values of electron swarm parameters obtained by TOF method. This study gained the values of the electron swarm parameters such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients for $SF_6$-He gas at a range of E/N. A set of electron collision cross section has been assembled and used in Monte Carlo simulation to predict values of swarm parameters. The result of Boltzmann equation and Monte Carlo Simulation has been compared with experimental data by Ohmori, Lucas and Carter. The swarm parameter from the swarm study are expected to sever as a critical test of current theories of low energy scattering by atoms and molecules.

지중튜브시스템 주요 설계 변수의 성능 평가 (Evaluation on the Performance of Design Parameters in Earth Tube System)

  • 황용호;황석호;최정민
    • 한국태양에너지학회 논문집
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    • 제36권3호
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    • pp.87-94
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    • 2016
  • Earth tube system can be installed in many ways. However, performance data on earth tube system is still insufficient. Therefore, in this study seven design parameters of earth tube systems were chosen such as underground earth tube length, depth, tube thermal conductivity, thickness, radius, soil conditions, and fan type. And the change effects in the values of the seven parameters on earth tube exit temperatures and heat transfer rate were examined through Energyplus simulations.

Effect of fiber and aggregate size on mode-I fracture parameters of high strength concrete

  • Kumar, Ch.Naga Satish;Krishna, P.V.V.S.S.R.;Kumar, D.Rohini
    • Advances in concrete construction
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    • 제5권6호
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    • pp.613-624
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    • 2017
  • In this paper, an experimental investigation was carried out to study the effect of volume fraction of fiber and maximum aggregate size on mode-I fracture parameters of high strength concrete. Total of 108 beams were tested on loading frame with three point loading, the variables in the high strength concrete beams are aggregate size (20 mm, 16 mm and 10 mm) and volume fraction of fibers (0%, 0.5%, 1% and 1.5%). The fracture parameters like fracture energy, brittleness number and fracture process zone were analyzed by the size effect method (SEM). It was found that fracture energy (Gf) increases with increasing the Maximum aggregate size and also increasing the volume of fibers, brittleness number (${\beta}$) decreases and fracture process zone (CF) increases.

Application of Multichannel Quantum Defect Theory to the Triatomic van der Waals Predissociation Process

  • Chun-Woo Lee
    • Bulletin of the Korean Chemical Society
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    • 제12권2호
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    • pp.228-238
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    • 1991
  • Generalized multichannel quantum defect theory [C. H. Greene et al. Phys. Rev., A26, 2441 (1982)] is implemented to the vibrational predissociation of triatomic van der Waals molecules. As this is the first one of such an application, the dependences of the quantum defect parameters on energy and radius are examined carefully. Calculation shows that, in the physically important region, quantum defect parameters remain smoothly varying functions of energy for this system as in atomic applications, thus allowing us very coarse energy mesh calculations for the photodissociation spectra. The choice of adiabatic or diabatic potentials as reference potentials for the calculation of quantum defect parameters as done by Mies and Julienne [J. Chem. Phys., 80, 2526 (1984)] can not be used for this system. Physically motivated reference potentials that may be generally applicable to all kinds of systems are utilized instead. In principle, implementation can be done to any other predissociation processes with the same method.

동적 에너지 시뮬레이션을 이용한 PCM보드의 설계변수 분석에 관한 연구 (Analysis of PCM Wallboards Design Parameters using Dynamic Energy Simulation)

  • 이진욱;안상민;김태연;이승복
    • KIEAE Journal
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    • 제12권4호
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    • pp.97-104
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    • 2012
  • A phase-change material is a substance with a high heat of fusion which, melting and freezing at a certain temperature, is capable of storing and releasing large amounts of energy. Heat is absorbed or released when the material changes from solid to liquid. Therefore, PCMs are classified as latent heat storage (LHS) units. The purpose of this study is to analyze PCM wallboard design parameters using dynamic energy simulation. Among the factors of PCM, melting temperature, latent heat, phase change range, thermal conductivity are very important element to maximize thermal energy storage. In order to analyze these factors, EnergyPlus which is building energy simulation provided by department of energy from the U.S is used. heat balance algorithm of energy simulation is conduction finite difference and enthalpy-temperature function is used for analyzing latent heat of PCM. The results show that in the case of melting temperature, the thermal energy storage could be improved when the melting temperature is equal to indoor surface temperature. It seems that when the phase change range is wide, PCM can store heat at a wide temperature, but the performance of heat storage is languished.

모듈형 동시냉난방 열펌프의 장배관/고낙차에 따른 액선 과냉도 변화에 대한 연구 (Study on longitudinal variation of subcooling with high elevated liquid line in a modular heat pump system)

  • 신광호;김민성;백영진;나호상;박성룡
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1255-1260
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    • 2008
  • This study is simulation of high elevated liquid line of a modular heat pump system to observe longitudinal subcooling variation. In a high elevated tube, subcooled refrigerant(R410A) through a condenser changes its states by heat transfer with surrounding air and by pressure drop from elevation. In this study, the liquid line was simulated through correlations of heat transfer and pressure drop for the variation from single-phase into two-phase flow. Pressure drop, heat transfer rate and vapor quality were calculated as key parameters. Two-phase turning heights and variations of the key parameters were confirmed from the simulation. As a result, high elevation of liquid line has great influence on upward flow, which requires additional equipment to compensate the variation.

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