• Title/Summary/Keyword: erosion rate

검색결과 534건 처리시간 0.022초

EFFECT OF COMPRESSIVE RESIDUAL STRESS FOR CORROSION PROPERTY OF SUP-9 STEEL USING AS SUSPENSION MATERIAL

  • Park, K.D.;Ki, W.T.;Shin, Y.J.;Ryu, H.J.
    • International Journal of Automotive Technology
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    • 제8권3호
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    • pp.343-349
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    • 2007
  • One of the useful technologies for light-weightening of components required in the automobile and machine industry is to use high strength materials. To improve material properties, the carbonizing treatment, nitrifying treatment, and shot-peening method are representatively applied. However, the shot-peening method is generally used to remove surface defect on steel and to improve the fatigue strength of the surface. Benefits of shot-peening are increasing resistance against fatigue, stress corrosion cracking, fretting, galling, erosion and closing of pores. In this paper, the effect of shot-peening on the corrosion of SUP-9 steel immersed in a 3.5% NaCl solution and corrosion characteristics from heat treatment during the shot peening process has been investigated. The immersion test was performed on four kinds of specimens. Corrosion potential, the polarization curve, residual stress etc. Were analyzed from the experimental results.

Detection of Forged Signatures Using Directional Gradient Spectrum of Image Outline and Weighted Fuzzy Classifier

  • Kim, Chang-Kyu;Han, Soo-Whan
    • 한국멀티미디어학회논문지
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    • 제7권12호
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    • pp.1639-1649
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    • 2004
  • In this paper, a method for detection of forged signatures based on spectral analysis of directional gradient density function and a weighted fuzzy classifier is proposed. The well defined outline of an incoming signature image is extracted in a preprocessing stage which includes noise reduction, automatic thresholding, image restoration and erosion process. The directional gradient density function derived from extracted signature outline is highly related to the overall shape of signature image, and thus its frequency spectrum is used as a feature set. With this spectral feature set, having a property to be invariant in size, shift, and rotation, a weighted fuzzy classifier is evaluated for the verification of freehand and random forgeries. Experiments show that less than 5% averaged error rate can be achieved on a database of 500 signature samples.

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축적 효과를 고려한 교각세굴 해석 프로그램 개발 (Development of Computer Program for Bridge Pier Scour Considering Accumulative Effect)

  • 곽기석
    • 한국지반공학회논문집
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    • 제17권3호
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    • pp.5-13
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    • 2001
  • 세립토에서의 세굴깊이의 발달은 일반적으로 조립토에서보다는 아주 천천히 진행된다. 조립토를 위해 개발된 방법을 시간효과와 무관하게 세립토에 적용한다면 세굴깊이가 과대하게 평가된다. SRICOS 방법은 점성토 또는 연암에 설치된 교각의 국부세굴깊이의 변화를 예측하기 위해 개발되었으며, 교량현장에서 채취한 흙에 대한 실험과 SRICOS 프로그램의 수행을 병행함으로써 적용된다. 본 논문에서는 SRICOS 방법을 간단히 설명한 후 프로그램의 세부적인 내용을 기술한다. 또한 이 프로그램을 이용하여 세굴에 미치는 각 매개변수의 영향을 평가하기 위해 실시한 매개변수 해석의 결과가 포함된다.

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알칼리 자극제 종류에 의한 고로슬래그 미분말 모르타르의 강도 특성 (Mechanical Properties of Blast Furnace Slag Fineness Mortar according to Alkali Activator)

  • 김종희;김규용;신경수;남정수;구경모;윤용상
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.217-218
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    • 2011
  • The advantages of blast-furnace slag concrete may include lower hydration heating velocity, restraint on concrete temperature increase, long-age strength improvement due to latent hydraulic reaction, improved water tightness, and repulsion to chemical erosion. These advantages contribute to the high quality of the blast-furnace slag concrete. However, the blast-furnace slag concrete has its limitations as well. These disadvantages may include retarded setting and elongated retention of mold due to the weak strength of early-age. Nevertheless, much research is currently under way to improve the aforementioned issues. To improve activity of blast furnace slag powder, alkaline irritants has been used. In this study, we analyze effect on activity fineness and rate of substitution of Alkali Activator toward activity.

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임기광산 폐석적치장의 수리침투특성 분석

  • 지상우;정영욱;임길재
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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    • pp.394-398
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    • 2004
  • This study was carried out to plan the prevention of the generation and discharge of acid mine drainage (AMD). Hydraulic characteristics were tested with the disk tension infiltrometer around the waste rock dump of the Imgi abandoned pyrophyllite mine in Busan, Korea. Because the waste rock dump of the Imgi mine have very low infiltration rate, most of rain was expected flowing into adjoined stream through the slope or plane as surface flow rather then throughflow or ground water. But slopes of the waste rock dump have many 'V' type erosion gullies and consist multi-layers. These gullies and multi-layers have coarse clastic particle layer which have very large hydraulic conductivity. So through these coarse clastic particle layers a large part of rain flow into ground. And also these layers could be played a function of aeration path, which induced oxidation of sulfide minerals and generation of AMD continuously.tinuously.

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옥외용 실리콘 고무 절연재료의 전기적 특성 (The Electrical Properties Dependent on the Filler in Silicone Composite Material for Power Distribution)

  • 김정호;박용관;김인성;조한구;김희곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1597-1599
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    • 1996
  • In this study, we investigated the electrical characteristics such as tracking resistance, dielectric constant, insulating resistance, and arc resistance, of silicone rubber for outdoor use, and, focused on the tracking resistance. In the Inclined Plane Test, two kind of the contamination solutions were used, and their phenomena were observed. The average leakage current and the tracking breakdown time decreased, and erosion rate increased, using anionic surfactant added contaminant solution. The dielectric constant and dissipation factor were increased with increasing temperature.

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Gas 이송용 Utility Materials의 전해연마 특성에 관한 연구 (A Study on the Characteristics of Electro-Polishing and Utility Materials for Gas Transitting)

  • 안세원;이종형;박무수
    • 한국기계가공학회지
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    • 제3권3호
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    • pp.52-57
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    • 2004
  • Many kinds of gases, such as erosion gas, dilution gas, and toxic gas have been used in manufacturing process of LCD at semiconductor. In order to increase accumulation rate of manufacturing process, high degree of purity in these gases and minimized metalllic dust are required. All wetted stainless steel surface must be 316L electro-polished with $0254{\mu}m$ in average. Based on the AES analysis, Cr/Fe 11 and $Cr_2O_3$ thickness $25{\AA}$ are measured Molybdenum and silicon contaminants which is characteristic of stainless steel and oxygen were found on the surface.

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불평형 마그네트론 스파터링에 의한 AC PDP용 MgO 보호층의 최적형성조건에 관한 연구 (A Study on the Optimum Preparation Conditions of MgO Protecting Layer in AC PDP by Unbalanced Magnetron Sputtering)

  • 김영기;박정태;김규섭;조정수;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.1096-1098
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    • 1999
  • The performance of as plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the optimum preparation conditions of MgO Protecting layer by RF unbalanced magnetron sputtering(UBMS) in surface discharge type AC PDP. The samples prepared with the do bias voltage of -10V showed lower discharge voltage, lower erosion rate as a consequence of ion bombardment, higher optic transparency and higher crack resistance in annealing process than those samples prepared by conventional magnetron sputtering or E-beam eraporation.

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MgO Sputtering in the AC-PDPs with Monte Carlo Methods

  • Gill, Doh-Hyun;Kim, Hyun-Sook;Joh, Dae-Guen;Kim, Young-Guon;Choi, Eun-Ha;Cho, Guang-Sup
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.109-110
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    • 2000
  • Sputtering yield of MgO film in the AC-PDPs has been calculated by Monte Carlo simulation of ion scattering. In the ion energy range less than 50 eV, the sputtering yield is 4 ${\times}$ $10^{-4}$ for Xe ions and it is between 0.1 and 0.01 for He, Ne, and Ar ions. The erosion rate is estimated about $25{\AA}$ per hour for Xe ions in an actual PDP plasma for sustain and full white mode.

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Effect of Bias Voltage on the Micro Discharge Characteristics of MgO Film prepared by Unbalanced Magnetron Sputtering

  • Kim, Young-Kee;Park, Jung-Tea;Park, Cha-Soo;Cho, Jung-Soo;Park, Chung-Hoo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.101-102
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    • 2000
  • The performance of ac plasma display panels (PDP) is influenced strongly by the surface glow discharge characteristics on the MgO thin films. This paper deals with the surface glow discharge characteristics and some physical properties of MgO thin films prepared by reactive RF planar unbalanced magnetron sputtering in connection with ac PDP. The samples prepared with the de bias voltage of -10V showed lower discharge voltage, lower erosion rate by ion bombardment, higher optic transparency and higher crack resistance in annealing process than those samples prepared by conventional magnetron sputtering or E-beam evaporation.

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