• Title/Summary/Keyword: critical charges

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Hydrophilic and Hydrophobic Group Characteristics for Nonionic Surfactants (비이온 계면활성제에 대한 친수성기와 소수성기의 그룹 특성)

  • Ha, Youn-Shick;Son, Man-Shick;Paek, U-Hyon
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.57-64
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    • 1994
  • On the basis of the principle of Bratch's electronegativity equalization, we calculated group partial charges and group electronegativities for nonionic surfactants with Pauling's elecoonegativity parameters by using numerical calculation method. From calculated outputs we have investigated structural stability of micelle, characteristics of hydrophilic and hydrophobic groups, and relation between CMC(Critical Micelle Concentraion) and group partial charge and group electronegativity of hydrophilic and hydrophobic groups for nonionic surfactants. We have known that CMC by micelle formation depends upon group partial charge and group electronegativity of hydrophilic and hydrophobic groups for surfactants. Also, the structural stability of micelle in H2O solution is related to the electric double layer by the hydrophilic group of nonionic surfactants with H atoms in water CMC is diminished by the decrease of repeating units in hydrophilic group at constant hydrophobic group and is diminished by the increments of alkyl chains in hydrophobic group at constant hydrophilic group for nonionic surfactants. In conclusion, CMC is diminished because there is no electrostatic repulsion and is diminished of Debye length by the increments of partial charge of hydrophobic group.

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A Study on the corrosion property by post treatment in the metal dry etch (Metal 건식각 후처리에 따른 부식 특성에 관한 연구)

  • Mun, Seong-Yeol;Kang, Seong-Jun;Joung, Yang-Hee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.747-750
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    • 2007
  • This study proposes that chlorine residue after metal etch as the source of metal corrosion, and charges should be removed by optimizing etch, PR strip and cleaning condition. Charges distributed along the metal line acts as a source of tungsten (W) plug corrosion when associated with following cleaning solution. In cleaning process after metal etch and PR strip, chemical selection is significantly important in terms of metal corrosion. Optimal corrosion preventive PH, no metal attack (choice of optimal inhibitants), high by product removal efficiency and optimal de ionized water treatment condition is critical to the metal corrosion prevention.

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Transient Analysis of PT-IGBTs at High Temperature

  • Ryu Sehwan;Lee Hokil;Ahn Hyungkeun;Han Deuk-Young
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.39-43
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    • 2001
  • In this paper, excess minority carrier distribution in drift and buffer layers and accumulated charges for PT IGST have been, for the first time, analytically expressed with different transient times, lifetimes and temperatures. Furthermore those parameters are also expressed with temperature to predict the transient response which are critical to the real operation. Active base region has been chosen to extract the temperature dependency of the device by including the buffer layer which is important but neglected due to the complexity up to now.

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Capacitance-Voltage Characteristics of MIS Capacitors Using Polymeric Insulators

  • Park, Jae-Hoon;Choi, Jong-Sun
    • Journal of Information Display
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    • v.9 no.2
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    • pp.1-4
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    • 2008
  • In this study, we investigate the capacitance-voltage (C-V) characteristics of metal-insulator-semiconductor (MIS) capacitors consisting of pentacene, as an organic semiconductor, and polymeric insulators such as poly(4-vinylphenol) (PVP) orpolystyrene (PS) prepared by spin-coating process, to analyze the interfacial characteristics between pentacene and polymeric insulators. Compared with the device with PS, the MIS capacitor with PVP exhibited a pronounced shift in the flat-band voltage according to the bias sweep direction. This hysteric feature in the C-V characteristics is thought to be attributed to the trapped charges at the interface between pentacene and PVP owing to the hydrophilicity of PVP. From the experimental results, we can conclude that surface polarity of polymeric insulator has a critical effect on the interfacial properties, thereby affecting the bias stability of organic thin-film transistors.

An Efficient Error Detection Technique for 3D Bit-Partitioned SRAM Devices

  • Yoon, Heung Sun;Park, Jong Kang;Kim, Jong Tae
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.5
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    • pp.445-454
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    • 2015
  • As the feature sizes and the operating charges continue to be scaled down, multi-bit soft errors are becoming more critical in SRAM designs of a few nanometers. In this paper, we propose an efficient error detection technique to reduce the size of parity bits by applying a 2D bit-interleaving technique to 3D bit-partitioned SRAM devices. Our proposed bit-interleaving technique uses only 1/K (where K is the number of dies) parity bits, compared with conventional bit-interleaving structures. Our simulation results show that 1/K parity bits are needed with only a 0.024-0.036% detection error increased over that of the existing bit-interleaving method. It is also possible for our technique to improve the burst error coverage, by adding more parity bits.

A Review about the Importance of Protonation of Ionizable Molecules on the Predictability of CoMFA

  • Kothandan, Gugan
    • Journal of Integrative Natural Science
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    • v.4 no.2
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    • pp.99-102
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    • 2011
  • Effect of protonation and deprotonation of ionization compounds is an important application in Comparative molecular field analysis (CoMFA). There are enough information's were reported about different CoMFA applications such as Series design and selection of training set, Geometries and optimizations of molecules, Effect of partial atomic charges, bioactive conformations and alignment, Interaction energy fields, Effects of different grid spacing etc. However limited information's are available about the ionization of compounds. This study aimed at the critical review of about the effects of protonation of ionizable molecules and its impact on the predictability of CoMFA models. We also discussed about previous implications and the things needed to be considered to come for a final conclusion about its impact on CoMFA predictability.

Demand Response of Large-Scale General and Industrial Customer using In-House Pricing Model (사내요금제를 활용한 대규모 수용가 수요반응에 관한 연구)

  • Kim, Min-Jeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.7
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    • pp.1128-1134
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    • 2016
  • Demand response provides customer load reductions based on high market prices or system reliability conditions. One type of demand response, price-based program, induces customers to respond to changes in product rates. However, there are large-scale general and industrial customers that have difficulty changing their energy consumption patterns, even with rate changes, due to their electricity demands being commercial and industrial. This study proposes an in-house pricing model for large-scale general and industrial customers, particularly those with multiple business facilities, for self-regulating demand-side management and cost reduction. The in-house pricing model charges higher rates to customers with lower load factors by employing peak to off-peak ratios in order to reduce maximum demand at each facility. The proposed scheme has been applied to real world and its benefits are demonstrated through an example.

A Study on Shock-induced Detonation in Gap Test (충격 전달에 의한 Gap Test의 폭굉 반응 해석)

  • Kim, Bohoon;Kang, Wonkyu;Jang, Seung-gyo;Park, Jungsu;Yoh, Jai-ick
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.2
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    • pp.75-85
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    • 2016
  • A pyrotechnic system consisting of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor charges. Despite of its common use, numerical study of such pyrotechnic train configuration is seldom reported because proper modeling of the full process requires precise capturing of the shock wave attenuation in the gap prior to triggering a full detonation of high explosive and accurate description of the high strain rate dynamics of the explosively loaded inert confinements. We apply a Eulerian level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized RDX as acceptor charge. The complex shock interaction, critical gap thickness, acoustic impedance, and go/no-go characteristics of the gap test are quantitatively investigated.

Development of Low-voltage Seamless Transfer Microgrid on Grid-connected Type Islands by Autonomous Operation (자율운전에 의한 계통연계형 도서의 저압 무순단 마이크로그리드 구축)

  • Kim, Jeong Hun;Kwon, Jung-Min;Yun, Sang-Yun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.169-176
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    • 2017
  • This paper presents research on low-voltage microgrids to maintain a continuous power supply to critical loads on grid-connected islands in Korea. The low-voltage microgrids of this paper focused on that changes public office buildings into uninterrupted microgrids by autonomous operation. For this, a microgrid controller (MGC) and a power conditioning system (PCS) that allow a seamless transfer between grid-connected and grid-isolated operation are proposed. The proposed PCS operates with a silicon controlled rectifier (SCR) switch and employs a simple structure. It supplies power continuously without operators through a coordinated operation between MGC and PCS. In addition, proposed MG has a schedule operation for minimizing electricity charges and provides ancillary services that enable the utilization of resources according to the operation purpose of utility distribution networks. To demonstrate the uninterrupted low-voltage microgrid proposed in this study, a microgrid was implemented and tested in a public office building in Anjwa Island, Jeollanam-do in Korea. A seamless, autonomous operation history, despite system disturbances, was obtained through a long-term demonstration of operation. The results showed that the proposed microgrid technology can be used to achieve energy resilience in grid-connected island areas.

Critical Overview on Changes of Judicial Precedents in the Medical Cases of Korea - In Relation with Forms of Judgments and Damages - (우리나라 의료판례 변화에 대한 비판적 고찰 - 판결양식과 손해배상액을 중심으로 -)

  • Shin, Hyun Ho
    • The Korean Society of Law and Medicine
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    • v.15 no.1
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    • pp.83-122
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    • 2014
  • Compared with medical cases and health care law from other countries there has been a lot of progress on medical law, especially on medical precedents in Korea. However, in recent years, medical precedents tend to reflect a realistic position of health care providers, rather than normative position of the victim. The burden of proof to prove strict liability is given to patients in civil law suits by courts, patients generally has the burden of proof. The rate of claims to prove the negligence of medical malpractice is falling significantly. Even if the error is acknowledged, it is not enough to get right to be relief for patients by increasing limitations of liability or ratio of patient's own negligence. Compensation fee is included in medical fees and risk of medical malpractice actions contributes ultimately to a health care consumer. In conclusion, author represents a major the new upgrade of above mentioned problem. By advising that court should assess actively for the perspective of victim for medical negligence we will be able to exercise remedies of patients' rights and to prevent recurring medical accidents and also contribute to medical advances.

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