• Title/Summary/Keyword: Unit-cell Concept

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Re-organization of Parametric epidermis (파라메트릭 표피 재 조직화)

  • Park, Jeong-Joo
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2008.05a
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    • pp.46-49
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    • 2008
  • This research does Complexity form, Interior epidermis cell re-organization, Object discovery that have correct numerical value concept by purpose. Research applied by Grid re-organization in form generation, Parameter variation of cell unit (morphor, tweener), Symbol, pattern of variation, self-organization cell substitution order. Representation through 3d digital modeler of polygon, Nurbs and street-sheet program(x,y,z coordinates & Network way of points) etc. of main work. Investigator specified numbers of U profiles*30, V point-20 that is 600 Paramaters individual in volume, and define circle radius of lighting in object, Projection size variously and tried difference. Transposition cell to point and Heightened brightness of color using pointillism of painting. Led lighting cell object is expressed being decoded by digital code.

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TA Study on the Performance and the Efficiency in Polymer Electrolyte embrane Fuel Cell (고분자전해질형 연료전지의 성능해석 및 효율에 관한 연구)

  • Kim Hong-Gun;Kim Yoo-Shin;Yang Sung-Mo;Nah Seok-Chan
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.4
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    • pp.75-80
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    • 2005
  • An experimental study is carried out to investigate the performance and the efficiency humidifying Membrane Electrolyte Assembly and having the double-tied catalyst layers in a fuel cell system which is taken into account the physical and thermal concept. Subsequently, an electric output produced by PEMFC(Polymer Electrolyte Membrane Fuel Cell) is measured to assess the performance of a stack, and the efficiency is also evaluated according to the different situation in which unit cell is placed with and without the humidification of the MEA. It is found that the measured values of stack voltage and current are influenced by the stack temperature, humidification, and the double-tied catalyst layers which give more enhanced values to be applied to electric units.

The five elements of the cell

  • Chung, SunKu;Cha, Seongwon;Lee, Seo-Young;Park, Jung-Hyun;Lee, Siwoo
    • Integrative Medicine Research
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    • v.6 no.4
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    • pp.452-456
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    • 2017
  • Everything in the surrounding universe can be attributed into five elements. Human organs can be also linked to the five elements. Cells, the smallest unit of the human body, consist of cellular organelles as little organs. Here, we extended the concept of the five elements to a cellular level via the human organs, theoretically re-evaluating the overall association of cellular organelles in maintaining the homeostasis of cellular functions.

A Study on the Performance Evaluation of Double-Layered Catayst MEA (이중촉매 MEA의 성능평가에 관한 연구)

  • Kim Hong-Gun;Kang Sung-Soo;Kwac Lee-Ku;Kang Young-Woo
    • New & Renewable Energy
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    • v.2 no.2 s.6
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    • pp.50-59
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    • 2006
  • An experimental and numerical study is carried out to investigate the performance and the efficiency humidifying Membrane Electrolyte Assembly and having the double-layered catalyst in a fuel cell system which is taken into account the physical and thermal concept. Based on the principals of the problem, the equation of electronic charge conservation equation, gas-phase continuity equation, and mass balance equation are used for the numerical calculation. A unit cell for $200cm^2$ MEA is assembled and measured for finding better operational situation. After finding the optimal condition, 10 cell stacked PEMFC is fabricated. For the performance evaluation, V-I and power curves are examined in detail by changing the condition of humidity, temperature, pressure, thickness of catalyst and oxidant. It is found that the power is maximized around 500W at 80A.

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Optimal Electricity and Heat Production Strategies of Fuel Cell Device in a Micro-grid Energy System (마이크로 전력계통에서 연료전지 발전시스템의 전기/열의 최적운영 기법 연구)

  • Lee, Joo-Won;Park, Jong-Bae;Kim, Su-Duk;Kim, Chang-Seop
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.6
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    • pp.1093-1099
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    • 2009
  • Alternative energy sources such as renewable energy like solar power systems, wind power systems, or fuel cell power systems has been the rising issue in the electrical power system. This paper discusses an economic study analysis of fuel cells in the korean electricity market. It includes the basic concept of a fuel cell and the korean electricity market. It also describes the need of renewable energy and how the fuel cell is connected with the local grid. This paper shows the impact of production and recovering thermal energy of a grid-connected fuel cell power system. The profit maximization approach has been structured including electrical power trade with the local grid and heat trade within the micro-grid. The strategies are evaluated using a local load that uses electric and thermal power which has different patterns between summer and winter periods. The solution algorithm is not newly developed one, but is solved by an application called GAMS. Results indicate the need and usefulness of a fuel cell power system.

Development of High Efficiency Gas Turbine/Fuel Cell Hybrid Power Generation System (가스터빈/연료전지 혼합형 고효율 발전시스템 개발)

  • Kim Jae Hwan;Park Poo Min;Yang Soo Seok;Lee Dae Sung
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.243-247
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    • 2005
  • This paper describes an on-going national R&D program for the development of a gas turbine/fuel cell hybrid power generation system and related R&D activities. The final goal of this program is to develop a 200kW-c1ass gas turbine/fuel cell hybrid power generation system and achieve high efficiency over $60\%$ (AC/LHV). In the first phase of the development, a sub-scaled 60kW-class hybrid system based on the 50kW-class microturbine and the 5kW SOFC will be developed for the purpose of concept proof of the hybrid system. Core components such as the microturbine and the SOFC system are being developed and parallel preparation for system integration is being carried out. Before the core components are assembled in the final system. operating characteristics of a hybrid system are investigated from a simulated system where a turbocharger (microturbine simulator) and a modified fuel cell burner test facility (fuel cell simulator) are employed. The 60kW demonstration unit will be built up and operated to provide the valuable information for the preparation of the final full scale 200kW hybrid system.

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Fabrication and Performance of Anode-Supported Flat Tubular Solid Oxide Fuel Cell Unit Bundle (연료극 지지체식 평관형 고체산화물 연료전지 단위 번들의 제조 및 성능)

  • Lim, Tak-Hyoung;Kim, Gwan-Yeong;Park, Jae-Layng;Lee, Seung-Bok;Shin, Dong-Ryul;Song, Rak-Hyun
    • Journal of the Korean Electrochemical Society
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    • v.10 no.4
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    • pp.283-287
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    • 2007
  • KIER has been developing the anode-supported flat tubular solid oxide fuel cell unit bundle for the intermediate temperature($700{\sim}800^{\circ}C$) operation. Anode-supported flat tubular cells have Ni/YSZ cermet anode support, 8 moi.% $Y_2O_3$ stabilized $ZrO_2(YSZ)$ thin electrolyte, and cathode multi-layer composed of Sr-doped $LaSrMnO_3(LSM)$, LSM-YSZ composite, and $LaSrCoFeO_3(LSCF)$. The prepared anode-supported flat tubular cell was joined with ferritic stainless steel cap by induction brazing process. Current collection for the cathode was achieved by winding Ag wire and $La_{0.6}Sr_{0.4}CoO_3(LSCo)$ paste, while current collection for the anode was achieved by using Ni wire and felt. For making stack, the prepared anode-supported flat tubular cells with effective electrode area of $90\;cm^2$ connected in series with 12 unit bundles, in which unit bundle consists of two cells connected in parallel. The performance of unit bundle in 3% humidified $H_2$ and air at $800^{\circ}C$ shows maximum power density of $0.39\;W/cm^2$ (@ 0.7V). Through these experiments, we obtained basic technology of the anode-supported flat tubular cell and established the proprietary concept of the anode-supported flat tubular cell unit bundle.

Analysis for Properties of Ceramic/Metal Composite Based on Micromechanics of materials (세라믹/금속복합재료에 대한 미시역학적 특성해석)

  • 김병식;김태우
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.144-148
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    • 2001
  • A proper estimation of the mechanical properties for composites has been required for better design/selection of constituents for composite materials. Present investigation shows the simulation results for ceramic reinforced metal matrix composite under uniaxial transverse tensile loading. The resulting transverse mean stress with the transverse mean strain was described for composites as a function of the volume fraction with two different types of interfacial bonding: (1)strongly bonded interface, and (2)no bonded interface. A two-dimensional finite element modeling and analysis were conducted based on the unit-cell concept with an assumption of a regular square arrangement of the reinforcement within the composite. The mean stress was generally increased with the ceramic volume fraction for composite with strong interface bonding. The micromechanics concept combined with finite element modeling for composite can be used in order to predict the transverse properties of composites with a priori known properties of constituents.

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Effective Longitudinal Shear Modulus of Continuous Fiber-Reinforced 2-Phase Composites (연속섬유가 보강된 2상 복합재료의 종방향 전단계수 해석)

  • Lee, Dong-Ju;Jeong, Tae-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.9
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    • pp.2770-2781
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    • 1996
  • Longitudinal shear modulus of continuous fiber reinforced 2-phase composites is predicted by theoretical and numerical analysis methods. In this paper, circular, hexagonal and rectangular shapes of reinforced fiber are considered using unit cell concept. And fiber array is regular rectangular and hexagonal fiber arrangement. Longitudinal shear modulus is a function of fiber distribution pattern and fiber volume change. It is found that the rectangular array has a higher longitudinal shear modulus than the hexagonal one. Also, the rectangular fiber shape in lower fiber volume fraction and the circular fiber shape in higher fiber volume fraction show the higher longitudinal shear modulus. And it has been found that the theoretical and numerical predictions of the longitudinal shear modulus give a good agreement with the experimental data at lower fiber volume fraction. Both the distance and stress transfer between the fibers are discussed as the major determing factors.

Spatially Combined V-Band MMIC Coupled Oscillator Array in Waveguide (도파관 내에서 공간적으로 결합된 V-Band MMIC 결합 발진기 Array)

  • 최우열;김홍득;강경태;임정화;권영우
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.8
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    • pp.783-789
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    • 2002
  • In this paper, V-band MMIC coupled oscillator arrays are presented. In the proposed array, two push-pull patch antennas are synchronized by using strong electromagnetic coupling between two antennas. As a result, total size of the array is reduced and the array can be integrated in a single chip. To verify proposed array concept, two 1$\times$2 arrays are designed and fabricated using standard 0.15 um gate length pHEMT MMIC process. The circuits are mounted in an oversized waveguide and measured. The first array shows 0.5 dBm at 56.372 GHz and the second one has an output of 5.85 dBm at 60.147 GHz.