• 제목/요약/키워드: Electrically Conducting

검색결과 111건 처리시간 0.022초

염료감응 태양전지용 고성능 탄소 상대전극 제작 (Fabrication of High-performance Carbon Counter Electrode for Dye-sensitized Solar Cells)

  • 장연익;이승용;김동환;박종구
    • 한국분말재료학회지
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    • 제14권1호
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    • pp.44-49
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    • 2007
  • In the fabrication of dye-sensitized solar cells (DSSCs), carbon counter electrode has been tested for replacing the platinum counter electrode which has two drawbacks: limited surface area and high material cost. Poor mechanical stability of carbon layer due to weak bonding strength to electrically conductive TCO (transparent conducting oxide) glass substrate is a crucial barrier for practical application of carbon counter electrode. In the present study a carbon counter electrode with high conversion efficiency, comparable to Pt counter electrode, could be fabricated by adaption of a bonding layer between particulate carbon material and TCO substrate.

Numerical Modeling of an Inductively Coupled Plasma Sputter Sublimation Deposition System

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • 제23권4호
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    • pp.179-186
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    • 2014
  • Fluid model based numerical simulation was carried out for an inductively coupled plasma assisted sputter deposition system. Power absorption, electron temperature and density distribution was modeled with drift diffusion approximation. Effect of an electrically conducting substrate was analyzed and showed confined plasma below the substrate. Part of the plasma was leaked around the substrate edge. Comparison between the quasi-neutrality based compact model and Poisson equation resolved model showed more broadened profile in inductively coupled plasma power absorption than quasi-neutrality case, but very similar Ar ion number density profile. Electric potential was calculated to be in the range of 50 V between a Cr rod source and a conductive substrate. A new model including Cr sputtering by Ar+was developed and used in simulating Cr deposition process. Cr was modeled to be ionized by direct electron impact and showed narrower distribution than Ar ions.

EFFECT OF POROSITY ON THE TRANSIENT MHD GENERALIZED COUETTE FLOW WITH HEAT TRANSFER IN THE PRESENCE OF HEAT SOURCE AND UNIFORM SUCTION AND INJECTION

  • Attia, Hazem Ali;Ewis, Karem Mahmoud;Awad-Allah, Nabil Ahmed
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제16권2호
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    • pp.125-135
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    • 2012
  • The transient magnetohydrodynamic (MHD) generalized Couette flow with heat transfer through a porous medium of an electrically conducting, viscous, incompressible fluid bounded by two parallel insulating porous plates is studied in the presence of uniform suction and injection and a heat source considering the Hall effect. A uniform and constant pressure gradient is imposed in the axial direction and an externally applied uniform magnetic field as well as a uniform suction and injection are applied in the direction perpendicular to the plates. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the Hall current, the porosity of the medium and the uniform suction and injection on both the velocity and temperature distributions is investigated.

EFFECTS OF SORET AND DUFOUR ON NATURAL CONVECTIVE FLUID FLOW PAST A VERTICAL PLATE EMBEDDED IN POROUS MEDIUM IN PRESENCE OF THERMAL RADIATION VIA FEM

  • RAJU, R. SRINIVASA
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제20권4호
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    • pp.309-332
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    • 2016
  • Finite element method has been applied to solve the fundamental governing equations of natural convective, electrically conducting, incompressible fluid flow past an infinite vertical plate surrounded by porous medium in presence of thermal radiation, viscous dissipation, Soret and Dufour effects. In this research work, the results of coupled partial differential equations are found numerically by applying finite element technique. The sway of significant parameters such as Soret number, Dufour number, Grashof number for heat and mass transfer, Magnetic field parameter, Thermal radiation parameter, Permeability parameter on velocity, temperature and concentration evaluations in the boundary layer region are examined in detail and the results are shown in graphically. Furthermore, the effect of these parameters on local skin friction coefficient, local Nusselt number and Sherwood numbers is also investigated. A very good agreement is noticed between the present results and previous published works in some limiting cases.

나노 사이즈 폴리파이롤의 합성 조건에 따른 크기 변화 (Effect of Polymerization Conditions on the Size Development of Nano-sized PPy)

  • Kim, Hyemin;Park, Chong-Rae
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2003년도 가을 학술발표회 논문집
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    • pp.171-172
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    • 2003
  • Electrically conducting polymers have attracted a great deal of attention because of their unusual electronic Properties.1 One of them, polypyrrole has been widely studieddue to its high conductivity and good environmental stability. 2Especially polypyrrole nano-Particles and -fibers are interesting because of their unique properties and applications. Recently amorphous polypyrrole nano-particles were fabricated using microemulsion Polymerization at low temperature. (omitted)

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Boundary layer analysis of persistent moving horizontal needle in Blasius and Sakiadis magnetohydrodynamic radiative nanofluid flows

  • Krishna, Penem Mohan;Sharma, Ram Prakash;Sandeep, Naramgari
    • Nuclear Engineering and Technology
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    • 제49권8호
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    • pp.1654-1659
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    • 2017
  • The boundary layer of a two-dimensional forced convective flow along a persistent moving horizontal needle in an electrically conducting magnetohydrodynamic dissipative nanofluid was numerically investigated. The energy equation was constructed with Joule heating, viscous dissipation, uneven heat source/sink, and thermal radiation effects. We analyzed the boundary layer behavior of a continuously moving needle in Blasius (moving fluid) and Sakiadis (quiescent fluid) flows. We considered Cu nanoparticles embedded in methanol. The reduced system of governing Partial differential equations (PDEs) was solved by employing the Runge-Kutta-based shooting process. Computational outcomes of the rate of heat transfer and friction factors were tabulated and discussed. Velocity and temperature descriptions were examined with the assistance of graphical illustrations. Increasing the needle size did not have a significant influence on the Blasius flow. The heat transfer rate in the Sakiadis flow was high compared with that in the Blasius flow.

자기공명영상시스템에서의 의료용 리드선의 전자기적 호환 연구 (Electromagnetic Compatibility Study of a Medical Lead for MRI Systems)

  • 유형석
    • 전기학회논문지
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    • 제65권12호
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    • pp.2019-2022
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    • 2016
  • In the presence of an electrically conducting medical lead, radio frequency (RF) coils in magnetic resonance imaging (MRI) systems may concentrate the RF energy and cause tissue heating near the lead. A novel design for a medical lead to reduce this heating by introducing pins in the lead is presented. Peak 10 g specific absorption rate (SAR) in heart tissue, an indicator of heating, was calculated and compared for both conventional (Medtronic) lead design and our proposed design. Remcom XFdtd software was used to calculate the peak SAR distribution in a realistic model of the human body. The model contained a medical lead that was exposed to RF magnetic fields at 64 MHz (1.5 T), 128 MHz (3 T) and 300 MHz (7 T) using a model of an MR birdcage body coil. The proposed design of adding pins to the medical lead can significantly reduce the heating from different MRI systems.

MHD Hartmann flow of a Dusty Fluid with Exponential Decaying Pressure Gradient

  • ATTIA HAZEM A.
    • Journal of Mechanical Science and Technology
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    • 제20권8호
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    • pp.1232-1239
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    • 2006
  • In the present study, the unsteady Hartmann flow with heat transfer of a viscous incompressible electrically conducting fluid under the influence of an exponentially decreasing pressure gradient is studied. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below while the fluid is acted upon by an external uniform magnetic field applied perpendicular to the plates. The equations of motion are solved analytically to yield the velocity distributions for both the fluid and dust particles. The energy equations for both the fluid and dust particles including the viscous and Joule dissipation terms, are solved numerically using finite differences to get the temperature distributions.

인공 후각 시스템을 이용한 휘발성 화학물질의 분류 (Classification of Volatile Chemicals using Artificial Odour Sensing System)

  • 변형기;백승화;김현기
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1996년도 춘계학술대회
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    • pp.65-68
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    • 1996
  • Neural networks are increasingly being used to enhance the classification and recognition powers of data collected from sensor array. This papers reports the effectiveness of multilayer perceptron network based on back-propagation algorithm combined with the outputs from "Electronic Nose" using electrically conducting polymers as sensor materials. Robust performance and classification results are produced with preprocessing method.

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HYDROMAGNETIC ROTATING DISK FLOW OF A NON-NEWTONIAN FLUID WITH HEAT TRANSFER AND OHMIC HEATING

  • Attia, Hazem A.;Ewis, Karem M.;Abd Elmaksoud, Ibrahim H.;Awad-Allah, Nabil A.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제16권3호
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    • pp.169-180
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    • 2012
  • The steady hydromagnetic flow of an electrically conducting non-Newtonian fluid due to the rotation of an infinite disk is studied with heat transfer with the inclusion of the ion slip as well as Ohmic heating. The governing nonlinear momentum equations and energy equations are solved using the finite difference method. The numerical results indicate the important effect of the ion slip and the non-Newtonian fluid characteristics on the velocity and temperature distributions.