• Title/Summary/Keyword: Cell engineering

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Combined System of Solar Cell and Fuel Cell (태양광시스템과 연료전지시스템의 통합에 따른 패러데이 효율성)

  • Hwang, Jun-Won;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.122-122
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    • 2009
  • Development of renewable energy is promoted to achieve sustainability. So researchers are seeking and developing a new, clean, safe and renewable energy. Fuel cell energy and solar cell energy are expected to be one of the solutions. The emissions of fuel cell is low, the by-product is low, the by-product is only pure water. This paper presents the efficiency of the hybrid system organized with fuel cell and solar cell in faraday law.

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Performance Analysis of Coordinated Random Beamforming Technique in Multi-cell Environments

  • Lee, Jong-Min;Jung, Bang-Chul
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.393-398
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    • 2010
  • For multi-cell environments, coordinated random beamforming technique in multiuser MIMO(multiple-input multiple-output) broadcast channel is considered. In order to mitigate severe interference at receivers, the multi-cell environments might require complex transmitter and receiver design because the scheduler decision based on full channel state information (CSI) in one cell must be intertwined with decision made by other cells' CSI. With limited CSI, however, this paper considers a scheme of randomizing transmitters' beamforming but being coordinated with other cell transmitters. The transmitters in each cell share random beamforming patterns and schedule data transmission within coherent scheduling period. The corandomized beams allow the users to be selected with the highest SINRs even in multi-cell environments. We analyze the performance of the proposed scheme. And numerical results show that the scheme achieves better performance than the conventional random beamforming when applying to multi-cell environments.

Bistable Property in a Splay Cell with a Chiral Additive

  • Lee, Seo-Hern;Kim, Tae-Jin;Lee, Jong-Lac;Jung, Mi-Jun;Park, Kyoung-Ho;Lee, Gi-Dong;Yoon, Tae-Hoon;Kim, Jae-Chang
    • Journal of Information Display
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    • v.4 no.3
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    • pp.22-25
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    • 2003
  • In this paper, we propose the bistability the bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell and introduce a novel switching method for the bistable chiral-splay nematic cell in order to transit the LC director between the non-twisted state with splay and the 180$^{\circ}$ twist state.

Effects of Silkworm Hemolymph on Cell Viability and hCTLA4Ig Production in Transgenic Rice Cell Suspension Cultures

  • Cheon, Su-Hwan;Lee, Kyoung-Hoon;Kwon, Jun-Young;Ryu, Hyun-Nam;Yu, Da-Hyun;Choi, Yong-Soo;Kim, Dong-Il
    • Journal of Microbiology and Biotechnology
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    • v.17 no.12
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    • pp.1944-1948
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    • 2007
  • Silkworm hemolymph (SH), prepared from fifth-instar larvae of Bombyx mori and heat-treated at $60^{\circ}C$ for 30 min, was used to improve cell viability and the production of human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) in transgenic Oryza sativa L. cell suspension cultures. Even though SH could not elevate cell viability at the concentrations up to 3% (v/v), addition of 0.3% (v/v) SH to a culture medium enhanced the production of hCTLA4Ig by 36.8% over an SH-free medium. Moreover, the production period of hCTLA4Ig could be shortened in a 0.3% (v/v) SH-added medium compared with that in an SH-free culture. As a result, addition of 0.3% (v/v) SH improved the productivity of hCTLA4Ig significantly in transgenic rice cell cultures.

Poly (ADP-ribose) in the pathogenesis of Parkinson's disease

  • Lee, Yunjong;Kang, Ho Chul;Lee, Byoung Dae;Lee, Yun-Il;Kim, Young Pil;Shin, Joo-Ho
    • BMB Reports
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    • v.47 no.8
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    • pp.424-432
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    • 2014
  • The defining feature of Parkinson's disease is a progressive and selective demise of dopaminergic neurons. A recent report on Parkinson's disease animal model demonstrates that poly (ADP-ribose) (PAR) dependent cell death, also named parthanatos, is accountable for selective dopaminergic neuronal loss. Parthanatos is a programmed necrotic cell death, characterized by PARP1 activation, apoptosis inducing factor (AIF) nuclear translocation, and large scale DNA fragmentation. Besides cell death regulation via interaction with AIF, PAR molecule mediates diverse cellular processes including genomic stability, cell division, transcription, epigenetic regulation, and stress granule formation. In this review, we will discuss the roles of PARP1 activation and PAR molecules in the pathological processes of Parkinson's disease. Potential interaction between PAR molecule and Parkinson's disease protein interactome are briefly introduced. Finally, we suggest promising points of therapeutic intervention in the pathological PAR signaling cascade to halt progression in Parkinson's disease.

Characteristics of the Multi-kW Class Polymer Electrolyte Membrane Fuel Cell Stack for a Hybrid Electric Golf Cart

  • I.H. Oh;S.J. Shin;J.H. Jo;Park, S.K.;H.Y. Ha;S.A. Hong;S.Y. Ahn;Lee, Y.C.;S.A. Cho
    • Journal of Energy Engineering
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    • v.11 no.3
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    • pp.254-261
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    • 2002
  • The fabrication method for the main components of the polymer electrolyte membrane fuel cell stack such as electrodes, membrane-electrode assemblies, and bipolar plates was established for the effective electrode area of 240 ㎠. A counter-flow type 100-cell stack was fabricated by using the above components and then a maximum power of 7.44 kW for H$_2$/O$_2$ and 5.56 kW for H$_2$/air could be obtained at 70$\^{C}$ and 1 atm. It was seen that the distribution of the OCV for unit cells in the stack was uniform but the voltage deviation increased as the load increased due to the IR drop and the electrode polarization. The stack was applied to the power source of the fuel cell/battery hybrid electric golf car. It produced about 1 kW at a room temperature operation during the test run, which occupied about 43% of the total power required by the 2.3 kW motor.

A QoS-Guaranteed Cell Selection Strategy for Heterogeneous Cellular Systems

  • Guo, Qiang;Xu, Xianghua;Zhu, Jie;Zhang, Haibin
    • ETRI Journal
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    • v.28 no.1
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    • pp.77-83
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    • 2006
  • In order to improve the accuracy of cell selection in heterogeneous cellular systems, this paper proposes a fuzzy multiple-objective decision-based cell selection (FMDCS) strategy. Since heterogeneous cellular systems have different access technologies and multiple traffic classes, the strategy adopts cell type, data rate, coverage, transmission delay, and call arrival rate as evaluation indices, and uses different weight vectors according to the traffic classes of the mobile host. Then, a fuzzy multiple-objective decision algorithm is applied to select the optimal cell from all candidates. This paper also gives an instance analysis and simulation. The instance analysis shows FMDCS makes different selections for different traffic classes. Simulation results of the after-handoff quality-of-service (QoS) show the selected cell can provide MH optimal service.

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The New Modeling of Solar Cell for Virtual Implement Of Solar Cell (태양전지 가상구현 장치를 위한 새로운 태양전지 모델링에 관한 연구)

  • Lee B. I.;Ryu T. G.;Han J. M.;Choe G. H.
    • Proceedings of the KIPE Conference
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    • 2002.11a
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    • pp.69-73
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    • 2002
  • A study on photovoltaic system has a lot of problems. Such as repetition experiment in the same condition, development of MPPT(Maximum Power Point Tracking) algorithm, development of islanding detection algorithm and so forth. The reason Is that solar cell output characteristics are varied by insolarion and surface temperature of solar cell. Therefore, the assistance equipment is required which emulates the solar cell characteristics. In this paper, propose the new modeling of solar cell and verify this modeling using MATLAB simulation. And experiment virtual implement of solar cell system using this modeling.

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Research on the Power Drop of Photovoltaic Module’s Aging Through the Thermal Shock Test

  • Kang, MinSoo;Jeon, YuJae;Kim, DoSeok;Shin, YoungEui
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.5
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    • pp.268-273
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    • 2015
  • While analyzing the specimens before and after the thermal shock test, we found that the power drop rate of the bare cell was 5.08%, while the power drop rate of the ribboned cell was 16.49%. In comparative terms, the efficiency was lower at the ribboned cell than at the bare cell. While analyzing through EL (Electroluminescence) shots and cross sections, we tried to decipher the exact cause of the power drop. Although mere color change of the cell was observed at the surface of the bare cell, no abnormality could be found inside the cell. On the surface of the ribboned cell, the short circuit of gridfinger extended from the front part of the front electrode of the ribboned cells. Therefore, cracks occurred on the surface of the cell. Cracks also appeared inside the cell. While analyzing the I-V curve, we determined an increase in the leakage current and an increase of resistances in series in the bare cell. In the ribboned cell, the resistances in parallel reduced remarkably. An increase of resistances in series could also be verified. Conclusively, we deduced that the power drop rate in the bare cell is a life span of the cell itself; aging is the cause of power drop rate in cells. In case of ribboned cell, the power drop rate was directly influenced by internal cracks and an intermetallic compound layer joining the ribbon at the front electrode.