• Title/Summary/Keyword: uncoated

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Cutting Performance of TiAlN coated WC Insert Tip (TiAlN을 코팅한 WC공구의 절삭성능에 관한 연구)

  • 김형자;최현철;이규용
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.281-286
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    • 2001
  • TiAIN was deposited onto ISO P2O Cutting Insert Tip substrate by FVAS at the substrate temperature of 80$^{\circ}C$. Cutting and wear test have been performed with TiAIN coated and uncoated WC cutting tools, respectively. Uncoated WC cutting tool has been tested under similar cutting condition for comparison. Cutting force and tool wear of coated and uncoated carbide cutting tools were investigated by cutting length. In cutting test, cutting force of the coated insert tip was larger than the uncoated insert tip by tool wear. Configuration and wear of the coated tool were more stable and resistant than the uncoated. In tool life by the tool wear, the coated cutting tool life was rather longer than the uncoated when tested at high speed (V=250 m/min) than low speed (V=200 m/min), Cutting force, tool wear and life were analysised by tool dynamometer amp(3ch) and oscilloscope.

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Effect of Organic Lubricant Film on Various Properties of Galvannealed Steel Sheets (합금화용융아연도금강판의 품질특성에 미치는 유기윤활피막의 영향)

  • 김영근
    • Journal of the Korean institute of surface engineering
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    • v.36 no.2
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    • pp.176-184
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    • 2003
  • New lubricant film of organic and inorganic composite resin was developed to improve the press formability of galvannealed steel sheets (GA) for automotive body panels. The frictional coefficient of lubricant GA steel sheets is about 20% superior to that of uncoated GA. The current range of spot welding of lubricant GA is similar to that of the uncoated GA, but the burning trace of spot welding is inferior to that of the uncoated GA in the oiling condition. The alkaline degreasability of lubricant GA shows 100% in alkaline degreasing condition of automotive company. The size and shape of the phosphated coating layer are similar to those of the uncoated GA sheet. The powdering property of the lubricant GA gives rise to 20∼50% improved property compared with the uncoated GA sheet.

Growth Response of Bentgrass to Polymer Coated Urea (Bentgrass 생육에 미치는 Polymer Coated Urea의 효과)

  • ;;N.E.Cheistans
    • Asian Journal of Turfgrass Science
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    • v.11 no.2
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    • pp.97-104
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    • 1997
  • The objective of this study was to observe the differences in growth of creeping bentgrass turf to 'polymer coated urea fertilizer' and 'uncoated urea fertilizer', and to analyze durability of fertilizer effect with the 'polymer coated urea'. The experiment was initiated on June 3, 1996, at the Iowa State University Horticulture Research Station, north of Ames, Iowa. The experiment was conducted on an area of 'Penneagle' Creeping bentgrass(Agrostis palustris) maintained at fair-'way mowing height (1.3cm). The study was repeated at the same arrangement beginning on July 25, 1996. Visual quality data, clipping fresh and dry weight, and nitrogen(N) content in the clippings were taken weekly. Quality of the turf increased with increasing N rate. While quality ratings were higher for turf receiving polymer coated urea than for turf receiving uncoated urea at several times following treatment, but not significant. Fresh and dry clipping weights were quite variable during the trial. Visual quality rating and clipping yields improved with increasing rates of N but these differences were not statically significant between polymer coated and uncoated urea treatment. The durability of fertilizer efficiency in polymer coated urea was not last longer compare with uncoated urea from two weeks after treatment. Higher rates of N application increased the concentration of N in tissue but no significant differences between turf plots receiving polymer coated and uncoated urea. Key words: Polymer coated urea, Creeping bentgrass, Fertilizer, Turfgrass.

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The Behavior of Axial Load Transfer for S.L. Coated Pile And Uncoated Pile (S.L. 도포 및 미도포 말뚝의 축하중전이거동)

  • 배기열;김정환;이민희;최용규
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.373-380
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    • 2002
  • In this study, In order to compare the behavior of axail load transfer for S.L. coated piles and uncoated piles installed at a field test site. During static pile load tests, axial load transfer for S.L. coated piles and uncoated piles were measured.

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IMPROIVING THE PERFORMANCE OF STREAMLINED BOATS BY ENAMEL COATING

  • V.M.Salokhe;D.Gee-Clough;N, Birewar
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.148-157
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    • 1993
  • A study was conducted to evaluate the effect of enamel coating on boat hull drag. The results were compared with drag required for varnished uncoated boats. Models of rice barge and fishing boat were used in this study. The speed range of 0.6 to 1.5㎧ at different loads varying from 6 to 9 kg for rice barge and 4.6 to 6.4kg for fishing boats were used during testing. The total weight of the coated and uncoated boats were kept the same. It was observed that the drag force required by the coated boats was less than identical uncoated ones at all speeds and loads. For both uncoated and coated the drag required increased with speed. The maximum recorded reductions in drag were 26% for the rice barge and 28% for the fishing boat model.

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The effects of composition on the wear characteristics of Al-Si alloys. (Al-Si 합금(合衾)의 마멸특성(磨滅特性)에 미치는 조성(組成)의 영향(影響))

  • Kwon, Hyuk-Moo;Chang, Choong-Kun;Shin, Se-Kyoon
    • Journal of Korea Foundry Society
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    • v.6 no.1
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    • pp.5-11
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    • 1986
  • The Wear Characteristics of Al-Si alloys were investigated with various Si contents by using the not-dispersed alloys and uncoated-graphite dispersed alloys. Uncoated-graphite dispersions were accomplished by Vortex method carrying 1 hr. heating at $400^{\circ}C$ on uncoated-graphite. Wear loss were increased by increasing Si contents at the elevated final load. Hyper-eutectic alloys showed higher wear resistance values at the small final load of 2.1Kg and 3.2Kg, but at the more increased final load, hypo-eutectic alloys showed higher wear resistance values than hyper-eutectic alloys. The property of wear resistance of uncoated-graphite dispersed Al-Si alloys showed more good values than not-dispersed alloys. This peroperty of increased war resistance were resulted from lubricating action of dispersed graphite.

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Quality Changes of Yoghurt Added with Microencapsulated Iron during Storage (미세피복된 철분을 첨가한 요구르트의 저장 중 품질 변화)

  • 김윤지;윤칠석
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.542-546
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    • 1999
  • Uncoated, ethyl cellulose(EC) coated or methacrylic acid copolymer(MAC) coated ferrous sulfate was added to the yoghurt made from whole milk powder and quality changes of those yoghurt were observed. Among treatments uncoated ferrous sulfate added yoghurt showed the lowest quality in the view of pH, total acidity, total counts of lactic acid bacteria, and sensory characteristics. Quality change of MAC comparing to control was lower than that of EC. MAC and EC showed higher TBA value than no iron added or uncoated iron added one during storage. From sensory evaluation, MAC was not signif icantly different from control in color and off flavor after one day storage(p>0.05), however significant difference was observed in off flavor after 7 day storage(p<0.05). From above results, MAC coated ferrous sulfate added yoghurt showed better quality than uncoated or EC coated ferrous sulfate added one during storage.

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THE STUDY OF THE DENTAL PLAQUE FORMATION ON DIFFERENT IMPLANT SURFACES (임플란트 표면에 따른 인공치면세균막 형성에 관한 연구)

  • Kim, Jin-Woo;Han, Se-Jin;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.3
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    • pp.325-340
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    • 2008
  • The purpose of this study was to evaluate the artificial dental plaque by Streptococcus mutans on 4 different implant surfaces. In this study, the specimens were divided into 4 groups according to implant surface treatment. Uncoated implant group(n=5) which has an uncoated, smooth surfaced implant(Osstem, Korea), SLA implant group(n=5) which has an sandblasted large grit and acid-etched surface implant(Bicon, USA). Oxidized implant group(n=5) which has an oxidized surfaced implant (Osstem, Korea), and RBM implant group(n=5) which has resorbable blasting media(RBM) surfaced implant(Osstem, Korea). Acquired pellicle by human saliva and dental plaque by Streptococcus mutans were made on each implant surface. To analyze the plaque condition on implants surfaces, cell count and optical density were taken as a microbiologic method, and SEM(Scanning Electronic Microscope) findings was also taken for evaluation of surface condition. The following results were obtained. 1. Cell counting results of artificial dental plaque were Uncoated group($658.0{\pm}102.0$), RBM group($878.0{\pm}170.0$), SLA group ($946.0{\pm}42.0$), Oxidized group($992.0{\pm}40.0$), and there was difference between Oxidized group and Uncoated implant group(p<0.05). In case of modified cell counting results by v/w% were RBM group($197.8{\pm}45.2$), Oxidized group($207.04{\pm}8.34$), Uncoated group($261.6{\pm}40.6$), SLA group($315.4{\pm}14.0$), and there was difference between RBM group and SLA group(p<0.05). 2. Optical density results of artificial dental plaque after ultrasonic treatment was that there was difference among groups, and optical density of RBM group was higher than that of Uncoated group(p<0.05). In case of modified optical density results by v/w%, there was difference among groups, and the modified optical density of Uncoated group and SLA group was higher than those of Oxidized group and RBM group(P>0.05). 3. SEM findings of artificial dental plaque on the surfaces of implant as follows; there were artificial dental plaque on the surfaces of all test implants. Streptococcus mutans and by-product were observed at 10,000 times magnified condition on all test implants. Adhesion area of artificial dental plaque was about 1/2 of total surface after 24 hours incubate at $37^{\circ}C$. These results showed that there were differences among implant surfaces on the growth of Streptococcus mutans, and bacteria and by-product were covered about 1/2 area of total implant surfaces at 24 hours incubate at $37^{\circ}C$.

Cooking Characteristics of Rice Coated with Prickly Pear Water Extracts (손바닥 선인장 물추출물로 가공한 유색미의 취반 특성)

  • 서성수;김미영;노홍균;김순동
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.5
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    • pp.733-737
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    • 2002
  • Cooking characteristics of rice uncoated and coated with prickly pear water extracts (4% v/w for rice) were investigated. Prickly pear contained 83.22 mg% of $\alpha$-aminoadipic acid and 75.61 mg% of tyrosine as major free amino acids. After cooking, the coated rice contained 1.66 mg% of $\alpha$-aminoadipic acid which was not found in the uncoated rice. The free amino acid composition of the coated rice revealed significantly higher contents (about 2.0 to 4.2 times) of arginine, histidine, leucine, lysine and tyrosine compared with those of the uncoated rice. The major minerals in the prickly pear were Ca, K and Mg accounting for 95% of the total minerals present. After cooking, the mineral contents in the coated rice were higher by 10~45% than those in the uncoated rice. The coated rice showed lower hardness, gumminess and brittleness, and higher cohesiveness than the uncoated rice. In sensory evaluation, there were no differences in sweet taste, and overall and color acceptability between the uncoated and coated rice. However, tile coated rice showed higher scores for savory and sticky taste than the uncoated rice.

Polymer-Coated Liposomes for Oral Drug Delivery (I): Stability of Polysaccharide-Coated Liposomes Against Bile Salts (고분자 코팅을 이용한 경구용 리포좀의 개발(I): 다당체로 코팅된 리포좀의 담즙산염에 대한 안정성)

  • Choi, Young-Wook;Hahn, Yang-Hee
    • Journal of Pharmaceutical Investigation
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    • v.22 no.3
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    • pp.211-217
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    • 1992
  • Stabilization of liposomes against degradation by bile salts has been investigated in order to develop a liposomal model system for oral drug delivery. Two polysaccharides, amylopectin (AP) and chitin (CT), were employed to coat both empty liposomes and bromthymol blue (BTB)-encapsulated liposomes by adsorption-coating techniques. Turbidity changes and BTB-release characteristics in pH 5.6 buffer solutions with or without bile salts, sodium cholate and sodium glycocholate, were observed to compare the differences between uncoated liposomes and polysaccharide-coated liposomes. Initial turbidities of both uncoated and polysaccharide-coated liposomes in buffer solution were kept constant within 3% range during 4 hours of experiments. But they were decreased in a different manner in bile salts-containing buffer solutions, showing 10% or less decrease for polysaccharide-coated liposomes and 25% or more decrease for uncoated liposomes. BTB release from uncoated liposomes has been greatly increased upto 90% after 4 hours in bile salts-containing buffer solution, which is a clue for breakdown of liposomal vesicles. However, polysaccharide-coated liposomes showed the controlled-release pattern which is proportional to square-root of time, followed by around 50% release for the same time period. Consequently, it is possible to conclude that these polysaccharide-coated liposomes might be an available system for oral delivery of a drug which is unstable in gut environment.

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