• Title, Summary, Keyword: abrasion

Search Result 1,129, Processing Time 0.081 seconds

Evaluation of Abrasion Resistance of Geosynthetics by Rotational Abrasion Test (회전마모시험에 의한 토목합성재료의 마모저항성 평가)

  • 전한용;류중재;허대영
    • Textile Science and Engineering
    • /
    • v.41 no.2
    • /
    • pp.133-139
    • /
    • 2004
  • Rotational abrasion test was applied to geosynthetics to examine the effects of surface damage type on the abrasion resistance using different friction brush type and sandpaper particle size. In this study, the effects of friction brush type and sandpaper particle size on abrasion resistance were investigated. Surface damage of geosynthetics by rotational abrasion test was interpreted based on the phenomenological results. Abrasion resistance of geosynthetics was examined through tensile strength changes before and after abrasion test. Nonwoven geotextiles showed severe surface damage with type B and C brushes. Geogrid and geomembrane showed slight surface damage by type A brush but was fractured by type B and C brush. When sandpaper was used, nonwoven geotextiles showed more severe surface damage than woven geotextile. Tensile strength changes of all geosynthetics were closely related to the surface damage after rotational abrasion test.

한국인의 치경부마모증 경험도에 관한 조사연구

  • So, Moon-Young
    • The journal of the Korean dental association
    • /
    • v.12 no.2
    • /
    • pp.107-111
    • /
    • 1974
  • In order to collect some necessary data to promote correcting the toothbrushing technic on the Korean public, the author had examined the number of present teeth on which had cervical abrasion and the most basic home dental care in 2,000 Korean male and female adults from 19 to 52 years in the age. Then, the cervical abrasion experience rate and the cervical abrasion experience teeth rate were calculated and evaluated. The obtained results were as follows: 1. Cervical abrasion experience rate was 32.45% 2. Cervical abrasion experience rate was gradually increased by ageing. 3. Cervical abrasion experience rate in male adults was higher than that in female adults. 4. Cervical abrasion experience rate in the lower jaw was higher than that in the upper jaw. 5. Cervical abrasion experience rate of the teeth at the right side was higher than that of the teeth at the left side. 6. Cervical abrasion experience teeth rate was 3.82%. 7. Cervical abrasion experience rate was highest on the first bicuspid, and followed in the sequence of the second bicuspid, canine, first molar, incisors, and 2nd and 3rd molars.

  • PDF

The Mechanical Properties and Abrasion Behavior of Warp Knitted Fabrics for Footwear

  • Jeon, Youn-Hee;Jeong, Won-Young;Park, Jung-Woo;An, Seung-Kook
    • Fibers and Polymers
    • /
    • v.4 no.4
    • /
    • pp.151-155
    • /
    • 2003
  • The abrasion behavior of three kinds of warp knitted fabrics, which are normally used for upper sole of footwear, was evaluated. We measured the changes of mechanical and structural properties of each sample as abrasion cycle increased. Each sample showed similar trends in compression and surface properties but there were significant differences in abrasion rate among the samples. The mechanical properties showed remarkable differences with directions. The frictional coefficient (MIU) of fabric surface increased at the beginning of abrasion and decreased as abrasion cycles increased. The weight and thickness of the fabric linearly decreased with abrasion cycles. The surface roughness (SMD) and the compressional resilience (RC) decreased as abrasion cycles increased while compressional energy (WC) increased.

An Experimental Study on the Abrasion Tests as a Result of using Materials of Full Denture Occlusal Surface (총의치교합면의 사용재료에 따른 마모도 측정에 관한 실험적 연구)

  • Cha, Sung-Soo
    • The Journal of Korean Academy of Dental Technology
    • /
    • v.5 no.1
    • /
    • pp.19-26
    • /
    • 1983
  • I got a conclusion as a result of that in case of constructing a full denture using acrylic resin teeth, porcelain teeth, and forming posterior occlusal surface of the artificial teeth by Type III Gold and Nickel crome alloy thus construdting a full denture and therefore comparing the above case with abrasion of Natural teeth. The result were as follows : 1. The abrasion of Natural teeth and the abrasion of full denture constructed by Type III gold has a close resemblance. 2. The one that has the hightest degree of abrasion is full denture that's using, with acrylic resin teeth, maxillary and mandibular And the lowest abrasion is natural teeth-natural teeth. 3. In case of single denture, that's opposing to natural teeth, the one that has the hightest degree of abrasion is a full denture that's using Acrylic resin teeth and the lowest abrasion is a full denture that's forming occlusal surface by Type III gold. 4. The single denture, which is opposing to type III gold teeth, was abraded above everything by full denture which is constructed by porcelain teeth. 5. In the same teeth, the abrasion of mandibular teeth was greater than that of mandibular teeth was greater than that of maxillary teeth. 6. The abrasion degree of Acrylic resin teeth has no direct mutual connection with material hardness which is opposing to.

  • PDF

Development of Composite Fly Ash Pipe (비회 운송용 유리섬유 복합관 개발)

  • Jeong, Gyu-Sang;Won, Sam-Yong;Moon, Jin-Sung
    • Proceedings of the KSME Conference
    • /
    • /
    • pp.33-36
    • /
    • 2007
  • The majority of fly ash pipes in thermal power stations use steel pipes. This makes frequent replacement inevitable due to severe abrasion near the hot and curved section of pipes. Recently, there have been efforts to prevent this abrasion with lining techniques using ceramic or basalt on the inner wall of the pipe. This study uses composite and anti-wear material to maximize the anti-abrasion effects on the hot section of the pipe. The thickness of the abrasion layer was determined by the abrasion ratio of material found through the experiment; the thickness of the reinforcement layer was determined by micromechanics. Experiments were conducted on epoxy resins to test for heat and abrasion. Anti-abrasion test using particle impingement was intended to recreate realistic conditions when abrasion occurs within the hot section of an actual pipe. This study analyzes the abrasion ratio obtained from both the specimen experiment and from on-site measurement and provides evidence that a combination of composites and anti-wear agent can be used to create a fly ash pipe that is lower in costs and higher in quality than what is used currently.

  • PDF

A STUDY ON THE CERVICAL ABRASION EXPERIENCE RATE IN KOREAN ADULTS (한국인의 칫솔사용에 따른 치경부 마모증 경험도에 관한 조사연구)

  • Lee, Tae-Won
    • The journal of the Korean dental association
    • /
    • v.15 no.12
    • /
    • pp.1023-1025
    • /
    • 1977
  • In order to collect some necessary data to promote correcting the toothbrushing method, the author had observed and evaluated the cervical abrasion experience rate in 1000 Korea male and female adults from 19 to 52 years in the age. The obtained results were as follows 1. Cervical abrasion experience rate was 26.1% 2. Cervical abrasion experience rate in male adults was higher than that in female adults. 3. Cervical abrasion experience rate was gradually increased by aging. 4. In Korean adults, the further detail investigations into the cervical abrasion were required.

  • PDF

A Study on Third Body Abrasion in the Small Clearance Region Adjacent to the Contact Area

  • Kim, Hyung-Kyu;Lee, Young-Ho;Heo, Sung-Pil;Jung, Youn-Ho
    • KSTLE International Journal
    • /
    • v.4 no.1
    • /
    • pp.8-13
    • /
    • 2003
  • Abrasion in fretting wear mechanism is studied experimentally with the specimens of two different shapes of spacer grid spring and fuel tubes of a nuclear fuel. Reciprocating sliding wear test has been carried out in the environment of air and water at room temperature. Especially, third body abrasion is referred to for explaining the wear region expansion found during the slip displacement increase with constant normal contact farce. It is found that the expansion behaviour depends on the contact shape. The small clearance between the tube and spring seems to be the preferable region of the wear particle accumulation, which causes third body abrasion of the non-contact area. Even in water environment the third body abrasion occurs apparently. Since the abrasion on the clearance contributes wear volume, the influence of the contact shape on the severity of third body abrasion should be considered to improve the grid spring design in the point of restraining wear damage of a nuclear fuel.

Abrasion of PET Fabrics by Using Microwave Energy (Microwave Energy를 이용한 PET 직물의 Abrasion)

  • Cho, In-Sul;Lee, Eun-Woo;Cho, Kyu-Min;Chang, Du-Sang
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.2 no.2
    • /
    • pp.69-72
    • /
    • 1999
  • The aim of this study is to enhance the abrasion of the hydrolyzed polyethylene terephthalate(PET) fabrics by using microwave energy. In other to achieve the aforementioned objectives, PET fabrics were hydrolyzed in NaOH solution by using abrasion method such as dipping, microwave-dipping, pad steam-dry, and pad microwave-dry, and then abrasion of the hydrolyzed PET fabrics was calculated and investigated. As a result obtained form this study, the abrasion of the hydrolyzed PET fabrics is directly proportional to hydrolyzed time and NaOH concentration. And also, microwave-dipping method and pad microwave-dry method showed remarkable abrasion effect than the others.

  • PDF

An Analysis on the Effect Factors of the Abrasion Resistance of Interlocking Concrete Block for Roadways (블록의 표층재료 특성이 마모저항성에 미치는 영향 분석)

  • Lee, Min-Kyoung;Cho, Yoon-Ho;Lee, Jae-Hoon;Park, Jun-Young
    • International Journal of Highway Engineering
    • /
    • v.14 no.5
    • /
    • pp.67-74
    • /
    • 2012
  • PURPOSES: In this study the influence factors related to abrasion resistance of interlocking concrete block have been evaluated, and comparisons between various domestic and foreign abrasion test methods was also accomplished. METHODS: The modified rotational cutting method suggested in ASTM C 944 was applied. Surface materials with different types of fine aggregate such as crushed sand, sea sand, and mixture of crushed and sea sand were tested to compare the aggregate effect for abrasion resistance. RESULTS: The different surface mixtures with various W/C ratios, mortar and fly ash ratios have been investigated for functional and economical considerations. CONCLUSIONS: This study had obtained reliable results by changing diamond blade of rotating cutter. Therefore, in order to improve the abrasion resistance of interlocking concrete block for road, a new mix design was proposed.

ABRASION RESISTANCE OF DENTURE BASE RESIN INCLUDING VINYLOLIGOSILSESQUIOXANE (Vinyloligosilsesquioxane 함유 의치상용 아크릴릭 레진의 마모 저항성)

  • Park Ran;Shim June-Sung;Han Dong-Hoo
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.41 no.5
    • /
    • pp.626-639
    • /
    • 2003
  • Statement of problem : Recently, in attempts to reinforce the acrylic resin and to reduce the polymerization shrinkage, it has been reported that adding vinyloligo-silsesquioxane (vinyl-POSS) to PMMA significantly compensates for polymerization shrinkage and somewhat increases the fracture resistance. Purpose : There haven't been any studies on abrasion that can affect the adaptation of the denture in long-term use. In this study abrasion resistance was compared between acrylic resin with vinyl-POSS and commercialized acrylic resin for denture base. In addition, the difference in abrasion resistance according to molding methods was compared. Material and method : Using PaladentR 20 including vinyl-POSS. PaladentR 20, Lucitone 199R, SR IvocapR, denture bases were fabricated using compression molding technique and continuous-pressure injection technique. Surface hardness and abrasion were measured for each group, and the worn surfaces were observed under a scanning electron microscope. Results : 1. When surface hardness was measured for each material and molding technique, there was no statistically significant difference among the materials. (p<0.05) 2. When same denture base material and molding technique were used, the abrasion due to toothpaste solution was 5 times as severe as the abrasion due to soap solution. 3, When toothpaste solution was used, the abrasion decreased in the order of PaladentR20, PaladentR 20 including vinyl-POSS, SR IvocapR, and Lucitone 199R. However statistically significant difference was seen only among PaladentR 20, SR IvocapR, and Lucitone 199R. (p<0.05). 4. When soap solution was used, the abrasion was more severe in PaladentR 20 and including vinyl-POSS PaladentR 20 groups than in SR IvocapR and Lucitone 199R groups. (p<0.05). Conclusion : Addition of vinyl-POSS doesn't improve the abrasion resistance, and the abrasion resistance was similar to those of existing materials. Additional studies under different conditions are needed. For clinical application of vinyl-POSS, further investigations with different requirements and conditions are necessary.