• Title/Summary/Keyword: Spacers

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Methodology for Optimizing Permittivity Distribution of 145 kV Miniaturized Functional Graded Spacer Using Non-Dominated Sorting Genetic Algorithm-II (비지배 정렬 유전 알고리즘-II를 이용한 145 kV급 축소형 경사기능성 적용 스페이서의 유전율 분포 최적화 방법론)

  • Noh, Yo-Han;Kim, Seung-Hyun;Cheong, Jong-Hun;Cho, Han-Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.3
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    • pp.225-230
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    • 2020
  • Recently, with the miniaturization of GIS, there is a need for the miniaturization of spacers as accessories. Miniaturized spacers make it difficult to secure adequate insulation distances, resulting in a more concentrated electric field at the triple junction of high-voltage (HV) conductor-insulator (spacer)-insulation gas (SF6), which is a weakness in GIS. Therefore, by introducing a new concept design technology, functionally graded material (FGM), which is recently applied to various materials and parts industries, three-dimensional control of the dielectric constant distribution in a spacer can be expected to alleviate triple-junction electric field occupancy and improve insulation performance. In this study, we propose an optimized model using NSGA-II to optimize the permittivity distribution of FGM applied spacer.

Multi-point Flexible Touch Sensor Based on Capacitor Structure Using Thin Copper-Plated Polyimide Film for Textile Applications

  • Lee, Junheon;Kim, Taekyeong
    • Textile Coloration and Finishing
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    • v.31 no.2
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    • pp.65-76
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    • 2019
  • A multi-point touch input sensor having different sizes or different capacitance touch points connected by only one pair of signal transmission lines was fabricated using a polyimide film coated with a thin copper plate. The capacitance increases with the decrease in the number of sheets of fabric spacers placed between the two sheets of the polyimide film. Therefore, the touch input sensor could be manufactured without fabric spacers, which was possible by the action of the polyimide film as a dielectric material in the capacitor. On the multi-point touch sensor, higher capacitance was obtained when pressing wider-area touch points with 10mm to 25mm diameter on average. However, the capacitance of a system comprising two sheets of touch sensors was considerably low, causing a serious overlap of the capacitance values according to the data collected from the reliability test. Although the capacitance values could be increased by stacking several sheets of touch sensors, the overlap of data was still observed. After reducing the size of all touch points to 10mm and stacking up to eight sheets of sensors, reliable and consistent capacitance data was obtained. Five different capacitance signals could be induced in the sensors by pushing touch points simultaneously.

Quench and Recovery Characteristics of Non-Inductively Wound HTS Coils with Various Winding (권선방식에 따른 무유도 권선형 HTS 코일의 퀜치 및 회복 비교특성)

  • Jo, Hyun-Chul;Chang, Ki-Sung;Kim, Young-Jae;Choi, Suk-Jin;Hwang, Young-Jin;Kim, Won-Cheol;Ko, Tae-Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.12 no.1
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    • pp.37-41
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    • 2010
  • To limit fault current in a power system, superconducting fault current limiters (SFCLs) using high temperature superconducting (HTS) coils have been developed by many research groups so far. Non-inductive winding of HTS coils used for SFCLs can be classified into solenoid winding and pancake winding. Each of winding is expected to have different quench and recovery characteristics because the structure of solenoid winding differs from pancake winding's. Therefore it is important to the SFCLs application to investigate characteristics of each winding. In this paper, we deal with quench and recovery characteristics of four kinds of winding : solenoid winding, pancake winding without spacers, and with spacers of 2 and 4 mm thickness. In order to obtain quench and recovery parameters of coils, short circuit tests were performed in liquid nitrogen.

Optimization of Curing Pressure for Automatic Pressure Gelation Molding Process of Ultra High Voltage Insulating Spacers (초고압 절연 스페이서의 자동가압 겔화 성형 공정을 위한 경화 보압의 최적화 )

  • Chanyong Lee;Hangoo Cho;Jaehyeong Lee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.1
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    • pp.56-62
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    • 2024
  • By introducing curing kinetics and chemo-rheology for the epoxy resin formulation for ultra-high voltage gas insulated switchgear (GIS) Insulating Spacers, a study was conducted to simulate the curing behavior, flow and warpage analysis for optimization of the molding process in automatic pressure gelation. The curing rate equation and chemo-rheology equation were set as fixed values for various factors and other physical property values, and the APG molding process conditions were entered into the Moldflow software to perform optimization numerical simulations of the three-phase insulating spacer. Changes in curing shrinkage according to pack pressure were observed under the optimized process conditions. As a result, it was confirmed that the residence time in the solid state was shortened due to the lowest curing reaction when the curing holding pressure was 3 bar, and the occurrence of deformation due to internal residual stress was minimized.

Harnessing CRISPR-Cas adaptation for RNA recording and beyond

  • Gyeong-Seok Oh;Seongjin An;Sungchul Kim
    • BMB Reports
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    • v.57 no.1
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    • pp.40-49
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    • 2024
  • Prokaryotes encode clustered regularly interspaced short palindromic repeat (CRISPR) arrays and CRISPR-associated (Cas) genes as an adaptive immune machinery. CRISPR-Cas systems effectively protect hosts from the invasion of foreign enemies, such as bacteriophages and plasmids. During a process called 'adaptation', non-self-nucleic acid fragments are acquired as spacers between repeats in the host CRISPR array, to establish immunological memory. The highly conserved Cas1-Cas2 complexes function as molecular recorders to integrate spacers in a time course manner, which can subsequently be expressed as crRNAs complexed with Cas effector proteins for the RNA-guided interference pathways. In some of the RNA-targeting type III systems, Cas1 proteins are fused with reverse transcriptase (RT), indicating that RT-Cas1-Cas2 complexes can acquire RNA transcripts for spacer acquisition. In this review, we summarize current studies that focus on the molecular structure and function of the RT-fused Cas1-Cas2 integrase, and its potential applications as a directional RNA-recording tool in cells. Furthermore, we highlight outstanding questions for RT-Cas1-Cas2 studies and future directions for RNA-recording CRISPR technologies.

Synthesis and Liquid Crystallinity of Polyurethanes, Poly(imide-urethane)s

  • Lee, Dong-Jin;Kim, Han-Do;Toshiyuki Uryu
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.9-13
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    • 1998
  • A number of papers concerning the preparation and physical properties of thermotropic polyurethanes have been reported,$^{1.2}$ since thermotropic polyurethanes were first reported by Iimura and coworkers.$^3$ We have been studying the synthesis of thermotropic para-type aromatic polyurethanes containing alkylene spacers.$^{4.7}$ .(omitted)

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Tight adhesion of plastic substrates for cell gap stability in flexible LCDs

  • Jin, Min-Young;Kim, Sang-Il;Souk, Jun-Hyung;Kim, Jae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.78-81
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    • 2008
  • We developed tight adhesion techniques of two plastic substrates to maintain cell gap stability for rugged flexible LCDs. By combining rigid spacers and several adhesion materials, we demonstrated mechanically very stable flexible LCDs against pressure and bending.

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Design and analysis of a newly devised linear flexure bearing(KIMM-LFB) for small precision reciprocating machines (소형 정밀 왕복동 기기용 선형 탄성 베어링 고유 모델(KIMM-LFB)의 설계 및 해석)

  • Choe Sang Gyu;Park Seong Je;Hong Yong Ju;Kim Hyo Bong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.344.1-344
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    • 2002
  • A newly devised linear flexures bearing (KIMM-LFB) for reciprocating machines is disclosed having improved reliability for long lift. KIMM-LFB is an integrated device comprising a axially moving diaphragm with circumferentially arranged arc-shaped flexure blades secured between rim and hub spacers, which turn out to have higher radial stiffness and lower Von-Mises peak stresses than the one with circumferential tangent cantilever flexure blades. (omitted)

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