• 제목/요약/키워드: Material Reduction Rate

검색결과 474건 처리시간 0.024초

합성절차에 따른 1차원 ZnO 나노구조의 형태조절과 특성평가 (Shape Control and Characterization of One-dimensional ZnO Nanostructures through the Synthesis Procedure)

  • 공보현;박태은;조형균
    • 한국전기전자재료학회논문지
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    • 제19권1호
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    • pp.13-17
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    • 2006
  • The one-dimensional ZnO nanostructures prepared through thermal evaporation under various cooling down procedures by changing the flow rates of the carrier gas and the reactive gas were investigated. The nanorod structures were changed into the nanonail types with a broad head through the reduction of the flow rate of the carrier gas. The decrease of the reactive gas reduced the length of the nail heads due to the limited mass transport of reactive gas. The intensity ratio of the ultraviolet emission/green emission of photoluminescence was proportional to the length of the broad head showing a larger surface area. The vertically aligned nanostructures were grown along the [0001] direction of ZnO regardless of the aligned directions. The crystal direction of the nanostructures was determined by that of the initial ZnO crystal.

MF 플라즈마-EGR 조합시스템에 의한 디젤기관의 배기 가스 특성 (The Characteristics of Exhaust Gas in Diesel Engine by Middle frequency Plasma-EGR System)

  • 김선호;박재윤;김종석;하현진;김종달;김형만
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.1139-1142
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    • 2003
  • NOx, Soot and other exhausted components already became a dangerous state as principal materials of the air pollution. Therefore, the exhausted regulations are getting strict in the many countries. In this paper, reduction characteristic of NOx, Soot and CO from diesel engine are investigated, when MF plasma-EGR hybride system is put to the diesel engine. NOx is decreased in all measured load and applied voltage to plasma renter However Soot is increased as increasing EGR rate and it is decreased as increasing applied voltage.

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기판의 왕복 운동을 이용한 인라인 식각세정장치 내 ITO 식각특성 (ITO Wet Etch Properties in an In-line Wet Etch/Cleaning System by using an Alternating Movement of Substrate)

  • 홍성재;권상직;조의식
    • 한국전기전자재료학회논문지
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    • 제21권8호
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    • pp.715-718
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    • 2008
  • An in-line wet etch/cleaning system was established for the research and development in wet etch process. The system was equipped with a reverse moving system for the reduction in the size of the in-line wet etch/cleaning system and it was possible for the glass substrate to be moved back and forth and alternated in a wet etch bath. For the comparison of the effect of the normal motion and that of the alternating motion on the in-line wet etch process, indium tin oxide(ITO) pattern was obtained through both wet etch process conditions. The results showed that the alternating motion is not inferior to the normal motion in etch rate and in etch uniformity. It is concluded that the alternating motion is possible to be applied to the in-line etch process.

레이저 빔에 의한 YBCO 표면변조 연구 (Study on YBCO Surface Modification by Laser Beam)

  • 정영식;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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    • pp.129-132
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    • 1996
  • Surface modification like cone formation on Pulsed laser deposition (PLD) occurs in YBCO target surface irradiated by laser beam. Cone formation results in a reduction of deposition rate, so that it is significant obstacles to an efficient deposition process. With the change of various conditions such as the number of laser shot, target density, direction of incoming laser beam, we have systematically analyzed the modification of target surface. Because cones formed by beam-target interactions grow in direction of incoming laser beam, we have used the method of rotating the target position by 180$^{\circ}$ with the same number and position of laser shot. Experimental results of losing the directionality and changing the shape of cones formed on laser irradiated YBCO target surface is obtained by the SEM image. Also, we have observed that the size of cones formed on target by pulsed laser became larger with increasing the number of laser shots.

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Dissolution Characteristics of ph-Dependent Antacid Granules Agglomerated in High Speed Agitation Type Speed Agitation Type Granulator

  • Choi, Woo-Sik;Lee, Jung-Sun
    • Archives of Pharmacal Research
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    • 제18권5호
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    • pp.314-319
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    • 1995
  • Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

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초분광 영상 특징선택과 밴드비 기법을 이용한 유사색상의 특이재질 검출기법 (Specific Material Detection with Similar Colors using Feature Selection and Band Ratio in Hyperspectral Image)

  • 심민섭;김성호
    • 제어로봇시스템학회논문지
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    • 제19권12호
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    • pp.1081-1088
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    • 2013
  • Hyperspectral cameras acquire reflectance values at many different wavelength bands. Dimensions tend to increase because spectral information is stored in each pixel. Several attempts have been made to reduce dimensional problems such as the feature selection using Adaboost and dimension reduction using the Simulated Annealing technique. We propose a novel material detection method that consists of four steps: feature band selection, feature extraction, SVM (Support Vector Machine) learning, and target and specific region detection. It is a combination of the band ratio method and Simulated Annealing algorithm based on detection rate. The experimental results validate the effectiveness of the proposed feature selection and band ratio method.

BSCCO-2223계 초전도 선재의 기계적 가공이 임계 전류 밀도에 미치는 영향 (The effect of mechanical processing in BSCCO-2223 tape on critical current density)

  • 임성우;강형곤;최명호;박경국;한병성
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.355-357
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    • 1998
  • BSCCO-2223 superconducting tape made by PIT method can be influenced in the critical characteristics by the heat treatment and the mechanical processing. Particulary, it has been reported that the mechanical deformation affects the core density, texture of the core, sausaging and so on. Therefore the accurate control of the deformation process is very important to achieve high J$\sub$c/. In this study, we measured the J$\sub$c/ variation for different rolling reduction rate and investigated the change of core shape to compare the formation of sausaging.

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다층형 단열재의 구성 형식에 따른 강도 특성 연구 (Strength Properties of Multi-layered Insulation according to the Type of Configuration)

  • 류화성;신상헌;송성용;김득모
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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    • pp.141-142
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    • 2019
  • As part of the recent low-energy policy, insulation standards for buildings are increasing every year. In addition, the conventional styrofoam heat insulation material has a problem in that the thickness of the heat insulation material to achieve the standard heat transmission rate is rapidly increased. Although the risk of spreading the structure vulnerable to fire due to insufficient spacing between buildings due to thickened insulation is increasing, the high cost of high efficiency insulation is difficult to solve. On the other hand, it is known that the method to be used as a formwork using insulation is excellent in cost reduction effect by reducing the amount of formwork used and simplifying the subsequent insulation work. The purpose of this study is to evaluate the strength characteristics of multi - layered insulation materials with appropriate strength by reducing the thickness of the insulation by appropriately combining high performance phenolic foam insulation and styrofoam insulation.

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폐자기를 사용한 마그네시아 인산염 세라믹(MPC) 인조석재의 내마모특성 (Abrasion Resistance Property of the Magnesia Phosphate Ceramics(MPC) Artificial Stone Using the Waste Porcelain)

  • 유용진;이상수;송하영
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.51-52
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    • 2014
  • Recently, it is the global warming phenomenon because of the greenhouse gas exhaustion caused by and the environment problem is serious. And it is the situation where the problem of the exhaustion of resource because of the indiscriminate picking of the that is the raw material of the cement, limestone and natural aggregate are emphasized. In addition, thus the cement reduction amount of use and substitute material research is the urgent actual condition with the gas emission, which here it is generated in conducting compression molding in the building stone manufacturing process performance degradation phenomenon and fire resistance, and problem of the durability. Therefore, in this research, because of being the magnesia phosphate ceramics, the waste porcelain is applied and the anti-wearing character of the artificial stone according to it tries to be investigated.

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CoolSiCTM SiC MOSFET Technology, Device and Application

  • Ma, Kwokwai
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2017년도 전력전자학술대회
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    • pp.577-595
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    • 2017
  • ${\bullet}$ Silicon Carbide (SiC) had excellent material properties as the base material for next generation of power semiconductor. In developing SiC MOSFET, gate oxide reliability issues had to be first overcome before commercial application. Besides, a high and stable gate-source voltage threshold $V_{GS(th)}$ is also an important parameter for operation robustness. SiC MOSFET with such characteristics can directly use existing high-speed IGBT gate driver IC's. ${\bullet}$ The linear voltage drop characteristics of SiC MOSFET will bring lower conduction loss averaged over full AC cycle compared to similarly rate IGBT. Lower switching loss enable higher switching frequency. Using package with auxiliary source terminal for gate driving will further reduce switching losses. Dynamic characteristics can fully controlled by simple gate resistors. ${\bullet}$ The low switching losses characteristics of SiC MOSFET can substantially reduce power losses in high switching frequency operation. Significant power loss reduction is also possible even at low switching frequency and low switching speed. in T-type 3-level topology, SiC MOSFET solution enable three times higher switching freqeuncy at same efficiency.

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