• Title/Summary/Keyword: abrasion

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Study on Adhesion Formation by Artificial Injuries in Rats (쥐에서 인공창상에 의한 유착형성에 관한 연구)

  • Kang Tae-Young;Choi Min-Cheol;Lee Hyo-Jong
    • Journal of Veterinary Clinics
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    • v.9 no.2
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    • pp.483-488
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    • 1992
  • This experiment was carried out to establish the grade of adhesion formation and changes of blood following artificial injuries such as abrasion, incision and electrocautery on colon and uterine horns in rats. 36 rats (abrasion-, incision-, electrocautery-treated groups) had laparotomy and abdominal injuries, twelve rats( control group) had only laparotomy, Ten days fellowing abdominal injuries, the score of adhesion formation and changes of blood were noted 1. Electrocautery-treated group was significant evident in adhesion formation in colon(p<0.01) and electrocautery and incision-treated groups were more evident than abrasion and control group in uterine horns(p<0.01) 2. Changes of erythrocytes number and PCV were tended to decrease during 5 days after operation, but recover normal level 10 days after operation. 3. Changes of leucocytes number were showed to significantly increase in electrocautery and incision-treated groups 5 days after operation. 4. The electrocautery-treated group was showed to significantly decrease in plasma protein and increase in plasma fibrinogen concentration.

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Wet Environmental and Mechanical Characteristics for Polyethylene-based Insulating Materials (Polyethylene 계열 절연재료의 환경적·기계적 특성)

  • Song, Woo-Chang;Choi, Won-Seok;Park, Ha-Yong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.2
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    • pp.119-123
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    • 2014
  • In this study, four kinds of specimens of PE(polyethylene)-based insulating materials were prepared for selecting the optimum insulation materials in a wet environment. The specimens were tested by various methods, the anti tracking test, the transmittance test in the water vapor transmittance(WVT) and the abrasion resistive test, etc. The HDPE(high-density polyethylene) specimen was showed excellent property in the tracking resistance test and the lowest transmittance in water vapor transmittance test. In the abrasion resistive test, the LLDPE(linear low-density polyethylene) and MDPE(medium-density Polyethylene) were showed excellent mechanical properties. The value of cut-through resistance for MDPE and HDPE were superior to that for LLDPE and LDPE(low-density polyethylene).

Correlation Between Drilling Parameter and Tunnel Support Pattern Using Jumbo Drill (도로터널에서 지보패턴별 굴착지수 상관관계 고찰)

  • Kim, Nag-Young;Kim, Sung-Hwan;Chung, Hyung-Sik
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.3 no.4
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    • pp.17-24
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    • 2001
  • Four road tunnels of which the construction conditions were similar were selected in the paper, and laboratory tests and rockmass classification for the tunnels were carried out. And the analysis was performed to find out the correlation between ratio of bit abrasion or drilling parameter and support pattern of tunnel using jumbo drill machine. It was analyzed that there was average abrasion of bit from 11.85% to 3.25% per support patterns of tunnel in four tunnels. Drilling parameter happens to fluctuate according to extent of fracture zone.

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The Study of Resistant Abrasion and Image Reproduction of the Photosensitive Plastic Convex Printing Plate for Securities Printing (유가증권 인쇄용 감광성 수지 볼록판의 내마모성 및 화선 재현에 관한 연구)

  • Kim, Byong-Hyun;Kang, Young-Reep;Lee, Hyok-Won
    • Journal of the Korean Graphic Arts Communication Society
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    • v.29 no.3
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    • pp.55-63
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    • 2011
  • The convex printing plate in particular securities is classified three physical properties. The main ingredient(component)of photosensitive plastic is composed of thermosetting polyamide. After being hardened specimen at $80^{\circ}C$ is shown to resist highly, the Glass Transition Temperatures of photosensitive plastic are $85^{\circ}C$. When hardened plate has reached at $80^{\circ}C$, abrasion loss is minimized. the cause is considered it is more effective in hardening when the temperature of photosensitive plastic is $80^{\circ}C$-the vitrification temperature of those. The hardness and the durability of the convex printing plate in particular securities are affected to the hardening treatment temperature. And the resolution of original drawing has being better when the durability is superior.

A Study on the Elimination Method of Noise Image Caused by Rainfall Using Machine Vision (머신비전을 이용한 판토그래프 습판 마모 측정에 있어서 우천으로 인한 영상노이즈 제거방법에 관한 연구)

  • Lee, Seong-Gwon;Lee, Dae-Won;Kim, Gil-Dong
    • Journal of the Korean Society for Railway
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    • v.12 no.3
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    • pp.364-369
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    • 2009
  • Pantograph sliding plate abrasion auto-detect system, one of the electric rail car auto-detecting devices, is a system that decides how much abrasion and when to replace without an inspector physically looking at the abrasion on the wet plate using machine vision, a cutting-edge technology. This paper covers the cause of deteriorating reliability that affects pantograph wet plate edge detection doe to noise added to the video when it rains. In order to remove such noise, problems should be checked through Smoothing, Averaging mask and Median filter using filtering technique and stable edge detection without being affected by noise should be induced in video measurement used in machine vision technology.

An embouchure aid for saxophone player (색소폰 연주자를 위한 앙부슈어 보조 도구의 제작)

  • Moon, Ho-Jin
    • Restorative Dentistry and Endodontics
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    • v.37 no.1
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    • pp.54-60
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    • 2012
  • This study aims to introduce the method that can relieve vibrating forces to oral environment by making an embouchure aid. Thin plastic crown forms were fabricated to prevent tooth abrasion and irritation to lip mucosa for the saxophone player. After application to the player, the most comfort form was chosen and delivered to 3 professional saxophone players. After 5 mon, the players responded to the survey. This embouchure aid did not disturb playing and gave comfort to lower lip. In general, the players preferred thin soft type and thought it caused little effect on sound. Far too little attention has been paid to the problems encountered by single-reed wind instrumentalist who suffer from tooth abrasion and irritation to lip mucosa. The embouchure aid not only prevent tooth damage but also diminish the discomfort of tight embouchure.

A study of characteristics by abrasion test of recycled aggregates (재생골재의 마모시험과 특성연구)

  • Song Young Joo;Park Kyoung Sub;Kong Kyoung Rok;Kang Heon Chan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.117-120
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    • 2005
  • It is necessary for decrease of building waste to increase using of recycled aggregate. However, the quality of those recycled aggregates is not good enough. This study aim at the rise of the quality through abrasion test and researching the characteristic change of the test. The samples of recycled aggregates had been divided into 10 sorts by the amount of cement paste, and then the abrasion rate of those divided aggregates has been figured out through this experiment. The result of this experiment shows that the quality of the recycled aggregates has been improved.

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Cure Characteristics, Mechanical Properties and Abrasion Resistance of Silica Filled Natural Rubber Vulcanizate

  • Lee, Hae Gil;Park, Chan Young
    • Elastomers and Composites
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    • v.50 no.3
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    • pp.159-166
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    • 2015
  • Silica which is used for reinforcing filler in tire industry is widely known as eco-friendly material exerting $CO_2$ reduction effect through decrease of rolling resistance and improvement of wet grip. Generally silica is classified as a highly polar filler because it contains a large number of silanol (Si-OH) group on its surface. And also silica gives a lower reinforcing effect than carbon black due to its poorer rubber-filler interaction. Therefore silica is treated with silane coupling agent or activator, then following the conventional rubber blend method, vulcanized sheets were prepared using a hot press, and cure characteristics, mechanical properties and abrasion resistance of the test specimens were investigated. It was found that with an increase in the silane coupling agent content the tensile strength, 300% modulus and abrasion resistance increased while Mooney viscosity decreased and crosslink density slightly increased with an increase of activator.

Effect of Matrix Phase on the Abrasive Wear Behavior of the High Cr White Iron Hardfacing Weld Deposites (고크롬 철계 오버레이용접층의 긁힘마모거동에 미치는 기지상의 영향)

  • 백응률
    • Journal of Welding and Joining
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    • v.16 no.1
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    • pp.114-124
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    • 1998
  • The effect of matrix phase (austenite, pearlite, martensite) on the low stress abrasion resistance in the chromium-carbide-type high Cr white iorn hardfacing weld deposites has been investigated. In order to examine matrix phase, a series of alloys with different matrix phase by changing the ratio of Cr/C system by heat treatment were employed. The alloys were deposited twice on a mild steel plate using self-shielding flux cored arc welding process. The low stress abrasion resistance of the alloys against sands was measured by the Dry Sand/Rubber Wheel Abrasion Test(RWAT). Even though formation of pearlite phase in the matrix showed higher hardness than that of austenite, there was no observable difference in wear resistance between the pearlite and austenite phase for the same amount of chromium-carbide in the matrix. On the other hand, the formation of martensitic phase,, from heat treated austenitic alloys (high content of Cr), enhanced wear resistance due to its fine secondary precipitates.

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Tribological and Mechanical Properties of UHMWPE/HDPE Composites

  • Na, Woo Seok;Lee, Kwang Ho;Kong, Tae Woong;Baek, Jung Youn;Oh, Jeong Seok
    • Elastomers and Composites
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    • v.53 no.4
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    • pp.234-238
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    • 2018
  • The influence of reinforcing UHMWPE powder on the tribological and mechanical properties of HDPE was investigated. The circularizing of UHMWPE powder was improved by high-speed rotation to enhance particle distribution and flowability. HDPE composites reinforced with UHMWPE powder in the range of 0-50 wt% were prepared by co-rotating twin screw extrusion. The abrasion resistance, plane friction coefficient, tensile strengths, and impact strengths of the composites were investigated as a function of the UHMWPE content. An increasing UHMWPE content decreased the plane friction coefficient and increased the abrasion resistance and impact strength. It is expected that HDPE composites reinforced with spherical UHMWPE powder particles can be used to improve the durability of products such as pipes in the future.