• Title/Summary/Keyword: Cross diffusion

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Glucose Diffusion Limiting Membrane Based on Polyethyleneimine (PEI) Hydrogel for the Stabilization of Glucose Sensor

  • Kim, Suk-Joon;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.12 no.2
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    • pp.225-229
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    • 2021
  • Commercially available continuous glucose sensors require the operation stability for more than two weeks. Typically, the sensor comprises a sensing layer and an over-coating layer for the stable operation inside the body. In the sensing layer, enzymes and mediators are cross-linked together for the effective sensing of the glucose. The over-coating layer limits the flux of glucose and works as a biocompatible layer to the body fluids. Here, we report the simple preparation of the flux-limiting layer by the condensation of polyethyleneimine (PEI), tri-epoxide linker, and trimethylolpropane triglycidyl ether (PTGE). The sensor is constructed by a layer-by-layer drop-coating of the sensing layer containing glucose dehydrogenase and the PEI-derived blocking layer. It is stable for more than 14 days, which is enough for the sensor in the continuous monitor glucose monitoring (CGM) system.

Monte Carlo Simulation of the Electron transport coefficients using Electron collision cross sections for $SP_{6}$ Gas ($SP_{6}$ 가스의 전자충돌단면적을 이용한 전자수송계수에 대한 몬테칼로 시뮬레이션)

  • 서상현;전병훈;하성철
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.152-157
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    • 1995
  • The electron transport coefficients in $SP_{6}$ gas is calculated and analysed for range of E/N values from 150∼800(Td) by a Monte Carlo simulation, using a set of electron collision cross sections determined by the authors. The result of the Monte Carlo simulation such as electron drift velocity, ionization and electron attachment coefficients, longitudinal and transverse diffusion coefficients in neatly agreement with the respective experimental and theoretical for a range of E/N. The validity of the results obtained has been confirmed by a Monte Carlo simulation carried out parallel to the analysis.

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Drift Velocities for Electrons in $SF_6$-Ar Mixtures Gas by MCS-Beq Algorithm (MCS-BEq에 의한 $SF_6-Ar$혼합기체(混合氣體)의 전자(電子) 이동속도(移動速度))

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.54 no.1
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    • pp.29-33
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    • 2005
  • Energy distribution function for electrons in $SF_6$-Ar mixtures gas by MCS-BEq algorithm has been analysed over the E/N range $30{\sim}300$[Td] by a two term Boltana equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other, authors, experimentally the electron swarm parameters for 0.2[%} and 0.5[%] $SF_6$-Ar mixtures were measured by time-of-flight(TOF) method. The result show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The results obtained from Booltemann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

Energy Distribution Function for Electrons in $SF_6+Ar$ Mixtures Gas used by MCS-BEq Algorithm (MCS-BEq에 의한 $SF_6+Ar$ 혼합기체의 에너지 분포함수)

  • Kim, Sang-Nam;Ha, Sung-Chul
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.878-881
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    • 2002
  • Energy distribution function for electrons in $SF_6+Ar$ mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30 ~ 300[Td] by a two term Boltzmann equation and by a Monte Carlo Simulation using a set of electron cross sections determined by other authors, experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6+Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced electron drift velocities, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients and mean energy agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

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FAST REACTOR PHYSICS AND COMPUTATIONAL METHODS

  • Yang, W.S.
    • Nuclear Engineering and Technology
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    • v.44 no.2
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    • pp.177-198
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    • 2012
  • This paper reviews the fast reactor physics and computational methods. The basic reactor physics specific to fast spectrum reactors are briefly reviewed, focused on fissile material breeding and actinide burning. Design implications and reactivity feedback characteristics are compared between breeder and burner reactors. Some discussions are given to the distinct nuclear characteristics of fast reactors that make the assumptions employed in traditional LWR analysis methods not applicable. Reactor physics analysis codes used for the modeling of fast reactor designs in the U.S. are reviewed. This review covers cross-section generation capabilities, whole-core deterministic (diffusion and transport) and Monte Carlo calculation tools, depletion and fuel cycle analysis codes, perturbation theory codes for reactivity coefficient calculation and cross section sensitivity analysis, and uncertainty analysis codes.

Re-determination of inelastic collision cross sections for $C_{3}F_{8}$ molecular gas in $C_{3}F_{8}-Ar$ mixture gases ($C_{3}F_{8}-Ar$혼합가스 상에서 $C_{3}F_{8}$분자가스의 비탄성단면적의 재결정)

  • Jeon, Byoung-Hoon
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.21-23
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    • 2005
  • The electron transport coefficients, the electron drift velocity W, the longitudinal diffusion coefficient $ND_L$ in $C_{3}F_{8}-Ar$ mixture gases were measured by Double shutter drift tube and calculated by multi-term approximation of the Boltzmann equation over the wide E/N range from 0.03 to 100 Td. And an inelastic collision cross sections for $C_{3}F_{8}$ molecular gas were redetermined for quantitative characteristic analysis.

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

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.1
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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.

Characteristics of copper wire wedge bonding

  • Tian, Y.;Zhou, Y.;Mayer, M.;Won, S.J.;Lee, S.M.;Cho, S.Y.;Jung, J.P.
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.34-36
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    • 2005
  • Copper wire bonding is an alternative interconnection technology that serves as a viable and cost saving alternative to gold wire bonding. In this paper, ultrasonic wedge bonding with $25{\mu}m$ copper wire on Au/Ni/Cu metallization of a PCB substrate was performed at ambient temperature. The central composite design of experiment (DOE) approach was applied to optimize the copper wire wedge bonding process parameters. After that, pull test of the wedge bond was performed to study the bond strength and to find the optimum bonding parameters. SEM was used to observe the cross section of the wedge bond. The pull test results show good performance of the wedge bond. Additionally, DOE results gave the optimized parameter for both the first bond and the second bond. Cross section analysis shows a continuous interconnection between the copper wire and Au/Ni/Cu metallization. The diffusion of Cu into the Au layer was also observed.

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The Technology Valuation Model for Technology of Management (기술경영을 위한 기술가치 평가모형)

  • Hong, Du-Wha;Park, Hae-Keun
    • Journal of the Korea Safety Management & Science
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    • v.8 no.4
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    • pp.63-89
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    • 2006
  • Recently, the technology is getting to be the most important factor for companies, as the industry is changing fast. The uncertainty and complexity of technology valuation arc higher so that the technology concentrated companies need more developed and high performance technology. This paper reviews the methods of technology valuation for five categories that have been developed by valuation researchers, (1) research of technology diffusion and acceptance model, (2) research of technology valuation, (3) research of technology import and export factor, (4) research of technology valuation model, (5) research of technology transfer and market. And we propose a new technology valuation model using need(market), seed(technology) and deeds(management) factor by cross impact matrix. This model gives us the reference negotiation range for deciding the amount of royalty. I hope this paper induces more research on this field of technology valuation.

Monte carlo simulation for electron transport characteristics in sulphur hexaflouride ($SF_6$ 가스의 전자수송특성에 관한 몬테칼로시뮬레이션)

  • 하성철;서상현
    • Electrical & Electronic Materials
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    • v.9 no.7
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    • pp.660-667
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    • 1996
  • The electron transport characteristics in $SF_6$ gas is calculated for range of E/N values from 150 -800(Td) by the Monte Carlo simulation using a set of electron collision cross sections determined by the authors. The results suggest that the value of an electron swarm parameter such as the electron drift velocity, the electron ionization or attachment coefficients, longitudinal and transverse diffusion coefficients in nearly agreement with the respective experimental and theoretical for a range of E/N. The electron energy distributions function were analysed in sulphur hexaflouride at E/N:500 and 800(Td) for a case of the equilibrium region in the mean electron energy. The validity of the results obtained has been confirmed by a Time of Flight method also investigated as a set of electron collision cross section for sulphur Hexaflouride.

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