• 제목/요약/키워드: Energy dependency

검색결과 292건 처리시간 0.024초

Kinetics of Initial Water Vapor Adsorption by Inonotus obliquus Mushroom Powders

  • Lee, Min-Ji;Seog, Eun-Ju;Lee, Jun-Ho
    • Preventive Nutrition and Food Science
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    • 제12권2호
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    • pp.111-114
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    • 2007
  • Water vapor adsorption kinetics of Inonotus mushroom powders were investigated in temperature and water activity ranges of 20 to 40$^{\circ}C$ and 0.30 to 0.81, respectively. Initial water vapor adsorption rate of mushroom powders increased with increases in temperature and water activity. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Water vapor adsorption kinetics of the mushroom powders can be well described by a simple empirical model. Temperature dependency of the reaction rate constant followed the Arrhenius relationship. The activation energy ranged from 56.86 to 91.35 kJ/mol depending on water activity. Kinetic compensation relationship was observed between k$_o$ and E$_a$ with the isokinetic temperature of 790.27 K.

稀土類元素의 溶媒抽出의 不均一性 (Nonmonotonic Ordering of Lanthanon Nitrates in the Phosphine Oxide Extraction Systems)

  • 이진택
    • 대한화학회지
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    • 제7권4호
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    • pp.271-276
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    • 1963
  • TBPO-toluene 및 TOPO-toluene 系에 대한 4f 稀土類元素의 硝酸鹽의 溶媒濃度, 硝酸基濃度 및 原子番號(Z)의 變化에 따르는 分配率의 變化를 放射化學的으로 測定하였다. log Kd 對 Z의 關係는 Z=63∼64에서 交叉되는 二個의 直線으로 表示되면 溶媒濃度 依存度는 稀土類元素 全般에 걸쳐 一定하나 硝酸基濃度 依存度는 經稀土類元素와 重稀土類元素가 다르게 나타난다.

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퍼지 슬라이딩 모드 제어기 및 신경망 보간기를 이용한 Underwater Flight Vehicle의 심도 제어 (Depth Control of Underwater Flight Vehicle Using Fuzzy Sliding Mode Controller and Neural Network Interpolator)

  • 김현식;박진현;최영규
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권8호
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    • pp.367-375
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    • 2001
  • In Underwater Flight Vehicle depth control system, the followings must be required. First, it needs robust performance which can get over modeling error, parameter variation and disturbance. Second, it needs accurate performance which have small overshoot phenomenon and steady state error to avoid colliding with ground surface or obstacles. Third, it needs continuous control input to reduce the acoustic noise and propulsion energy consumption. Finally, it needs interpolation method which can sole the speed dependency problem of controller parameters. To solve these problems, we propose a depth control method using Fuzzy Sliding Mode Controller with feedforward control-plane bias term and Neural Network Interpolator. Simulation results show the proposed method has robust and accurate control performance by the continuous control input and has no speed dependency problem.

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사장교 케이블의 감쇠성능 향상을 위한 댐퍼의 비선형성 연구 (Study of the Non-linearity of Cable Damper to Enhance Damping Performance of Stay Cable)

  • 서주원;고현무
    • 한국소음진동공학회논문집
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    • 제17권9호
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    • pp.785-796
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    • 2007
  • This study offers a design procedure of optimum cable damper for multi-mode vibration control with nonlinear damper and also investigates the relation between mode and amplitude dependency. The proposed multi-mode damping index, which is defined as a potential energy loss ratio of cable vibration, is a main component of optimization problem of optimum nonlinear damper. In order to include the amplitude dependency of nonlinear damper, three types of multi-mode patterns such as ambient vibration, support excitation and rain-wind induced vibration are assumed. The optimum damper exponent depends on amplitude patterns. In case of ambient vibration, optimum factor is less than 0.5 and in case of support excitation or rain-wind induced vibration it is between 0.5 and 1.0.

Analyses of on-the-fly generation of spectral superhomogenization factors for multigroup whole core calculation employing pin-wise slowing-down solutions

  • Seungug Jae;Han Gyu Joo
    • Nuclear Engineering and Technology
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    • 제55권3호
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    • pp.1084-1096
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    • 2023
  • On-the-fly(OTF) generation of Spectral Superhomogenization(SSPH) factors is analyzed in the multigroup(MG) whole core calculation employing pin-wise continuous energy(CE) slowing-down solutions. The motivation for the work is to avoid the huge computing time required for the generation of a parametrized SSPH factor library(PSSL) which is used to resolve the angular dependency of MG resonance cross sections, and also to exploit the advantage of flexible choice of a MG structure by using CE slowing-down solutions. Two pin-wise CE slowing-down methods, the equivalent Dancoff cell method and the shadowing effect correction method, are evaluated with the OTF SSPH method. The effectiveness of the OTF SSPH method is examined for various simplified and realistic core problems with various MG structures. It is demonstrated that the computing time overhead of this method is negligible whereas the solution accuracy is considerably enhanced.

The Effect of Processing Parameters on the Deposition Behavior of a Spent Fuel Surrogate in the Molten Salt Electrorefining

  • Lee, Jong-Hyeon;Kang, Young-Ho;Hwang, Sung-Chan;Kim, Eung-Ho;Yoo, Jae-Hyung
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2004년도 학술논문집
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    • pp.319-329
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    • 2004
  • The electrorefining experiments with an anode composed of U, Y, Gd, Nd and Ce (or U, Gd, Dy and Ce) were carried out in the KC1-LiCl eutectic melt at $500^{\circ}C$, Uranium was the major component in the cathode deposits at the high initial uranium concentration, and the separation factors of the uranium with respect to the rare earths (REs) were calculated according to the applied voltage and the uranium concentration in the molten salt. The current efficiency was inversely in proportion to the applied voltage in the range of 1.0 V to 1, 9 V (vs. STS304L). The dependency of the applied voltage on the current efficiency as well as the deposition rate was discussed in terms of the microstructural feature and crystal structure of the deposit.

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바이오매스 기반 전기에너지 생산기술 동향 분석 (Electrical Energy Production Using Biomass)

  • 이종서;한상수;김도연;김주현;박상진
    • 신재생에너지
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    • 제19권1호
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    • pp.12-21
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    • 2023
  • Governments and global companies are working towards using renewable sources of energy, such as solar, wind, and biomass, to reduce dependency on fossil fuels. In the defense sector, the new strategy seeks to increase the sustainable use of renewable energy sources to improve energy security and reduce military transportation. Renewable energy technologies are affected by factors such as climate, resources, and policy environments. Therefore, governments and global companies need to carefully select the optimal renewable energy sources and deployment strategies. Biomass is a promising energy source owing to its high energy density and ease of collection and harvesting. Many techniques have been developed to convert the biomass into electrical energy. Recently, diverse types of fuel cells have been suggested that can directly convert the chemical energy of biomass into electrical energy. The recently developed biomass flow fuel cell has significantly enhanced the power density several hundred times, reaching to ~100 mW/cm2. In this review, we explore various strategies for producing electrical energy from biomass using modern methods, and discuss the challenges and potential prospects of this method.

이코노마이저 제어 방법에 따른 사무소 건물의 냉방 에너지 성능 비교 (Comparison of Cooling-Energy Performance Depending on the Economizer-Control Methods in an Office Building)

  • 손정은;현인탁;이재호;이광호
    • 설비공학논문집
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    • 제27권8호
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    • pp.432-439
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    • 2015
  • Current building procedures seek to minimize external air supplies to reduce the energy consumption of air conditioning, resulting in a high dependency on mechanical ventilation. We therefore studied an economizer-cycle system, whereby the introduction of external air saves energy. We analyzed different economizer-control methods, addressing mixed-air temperatures and outdoor-air fractions according to outdoor-air temperatures; also, we analyzed the energy consumption of the three economizer-cycle control types using detailed EnergyPlus simulation modeling. A differential enthalpy control method showed a lower energy consumption range from 5.8% to 6.2% than that of other methods during the simulated period. A differential dry-bulb control method showed a 12.7% lower energy consumption than the no-economizer method in the intermediate period, but also showed 7.1% more energy consumption during the summer period. When latent heat was not removed due to high summer humidity, we found a significant level of resultant energy consumption.

Effects of Neutron Spectrum and Cross-section Library on Displacements per Atom (dpa)

  • Park, Duck-Gun;Shimakawa, S.;Nagao, Y.;Kang, Young-Hwan
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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    • pp.125-130
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    • 1997
  • Effect of cross-section libraries on displacements per atom (dpa) was investigated under the spectrum which is calculated in the outer and inner of capsule in the JMTR fuel region. The variation of dpa value of iron was calculated by TENJIN2 code using several cross section libraries (ENDFB-lV, JENDL 3.1 and JENDL 3.2). The dependency of input spectrum on total damage (dpa) is more clearly appeared in case or ENDFB-IV in JENDL 3.2 and JENDL 3.1 libraries. The gas production rate calculated by ENDFB-IV library showed slightly larger value than that by JENDL library, and it responded more sensitively in neutron spectrum.

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시멘트 기반 바이오매스 플라이애시 치환율에 따른 경화체의 물리적 특성 (Physical Properties of Matrix with Replacement Ratio of Biomass Fly Ash Based on Cement)

  • 김대연;조은석;이상수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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    • pp.209-210
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    • 2019
  • Current international concerns are the energy crisis due to climate change and depletion of fossil fuels due to global warming. Korea has a very high dependency on energy imports 93%. In Korea, 63% of the country is forested, and a power plant using wood biomass is being built in Korea. Biomass fly ash, a by-product of biomass energy generation, is now being discarded. There is little research to utilize discarded biomass fly ash. Therefore, this study aims to solve the environmental problems, develop new mixed materials, improve the quality and utilize the biomass fly ash, which is a by-product of the industrial waste. As a result of the experiment, the flowability decreased as the replacement ratio of biomass fly ash increased. As the replacement ratio of biomass fly ash decreased, the amount of air content.

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