• Title/Summary/Keyword: material combinations

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Analysis of Sliding Friction and Wear Properties of Clutch Facing for Automobile (Part 1) (자동차용 클러치 마찰재의 미끄럼마찰마모특성 해석(제1보 마모특성))

  • Lee Han-Young;Kim Geon-Young;Hur Man-Dae
    • Tribology and Lubricants
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    • v.20 no.6
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    • pp.299-305
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    • 2004
  • The wear properties of clutch facing materials with two different copper amounts were evaluated against the fly-wheel materials used in clutch system, such as gray cast iron and spheroidal graphite cast iron. Sliding wear tests were carried out for four different combinations with these clutch facing materials and flywheel materials at different speeds and applied loads. Results showed that the clutch facing material contained a higher copper amount had the better wear resistance. And using the gray cast iron as the counter material, clutch facing material resulted in the much lower wear rate, regardless of the copper amount. It is obvious that the wear properties of clutch facing material are influenced from the thermal conductivities of the clutch facing material and the counter material.

A Study on the Computer Assisted Dental Identification in Mass Disaster (대형참사시 컴퓨터를 이용한 법의치과학적 개인식별)

  • Shin, Kyoung-Jin;Choi, Jong-Hoon;Yoon, Chang-Lyuk;Kim, Chong-Youl
    • Journal of Oral Medicine and Pain
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    • v.24 no.1
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    • pp.81-94
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    • 1999
  • This study intends to find usefulness of the computer assisted dental identification in mass disaster. The variety of dental characteristics was investigated through the research of dental records of 508 adults. And a computer assisted simulation program was used to evaluate the selectivity of dental identification. Findings were as follows : 1. Combinations of dental characteristics were found 155 types. The most various dental characteristic was showed on the mandibular first molar. 99.0% of subjects had dental characteristics for dental identification. 2. The posterior teeth, in comparison with anterior teeth, showed higher selectivity in dental identification which was enhanced by information on the material, type and cavity of the restoration. 3. The variety of dental characteristics was mainly found on the combinations of missing tooth with the material, type and cavity of the restoration. 4. The computer assisted dental identification program, with informa- tion about one's tooth state, made individual identification possible when there was only a part of the teeth in a corpse. 5. The computer assisted dental identification had considerably high selectivity based on the variety of dental characteristics. And it was also performed faster and preciser than the existing identification methods. Based on the results of this study, there are various combinations of the feature of the tooth itself with dental characteristics caused by a certain type of treatment on the teeth. And using the computer assisted dental identification program based on this, dental identification can be more efficient economically and more useful than any other forensic identification methods.

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Comparison between reinforced concrete designs based on the ACI 318 and BS 8110 codes

  • Tabsh, Sami W.
    • Structural Engineering and Mechanics
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    • v.48 no.4
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    • pp.467-477
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    • 2013
  • Municipalities in the United Arab Emirates approve reinforced concrete design of building structures to follow either the ACI 318 or the BS 8110 code. Since the requirements of these codes are different from each, there is a need to compare the structural demand in the two codes. The main objective of this study is to compare the design requirements of the ACI 318 code with the BS 8110 code for the flexural, shear and axial compression limit states. The load factors and load combinations in the two codes are also compared. To do so, a large number of cross-sections with different geometries, material properties, and reinforcement ratios are analyzed following the procedures in the two codes. The relevant factored load combinations in the two codes are also investigated for a wide range of live-to-dead load ratios and for various wind-to-dead load ratios. The study showed that the differences between the design capacities in the ACI 318 and BS 8110 codes are minor for flexure, moderate for axial compression, and major for shear. Furthermore, the factored load combinations for dead load, live load and wind in the two codes yield minor-to-moderate differences, depending on the live-to-dead load ratio and intensity of wind.

The Effect of Heat Curing Methods on the Temperature History of the Fly Ash Concrete Subjected to Extremely Low Temperature (복합보온양생 방법이 극저온 조건하 플라이애시 치환 콘크리트의 온도이력에 미치는 영향)

  • Han, Min-Cheol;Son, Ho-Jung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.7 no.3
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    • pp.85-90
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    • 2012
  • In this study, temperature profile of the fly ash concrete were studied in accordance with the change of heating curing method combination for the slab concrete in order to develop efficient protection method of the concrete subjected to $-20^{\circ}C$. The slab concretes with the size of $1200mm{\times}600mm{\times}200mm$ were fabricated with W/B of 50% and exposed to $-20^{\circ}C$ for 7 days. Five different combinations of heat curing methods were applied to the slab concrete specimen; two combinations of heat supplying by electrical heater and surface heat insulation material such as polyethylene film and quadrupled layer bubble sheet based on heat enclosure installment; three combinations of heating coil embedment and surface heat insulation materials such as polyethylene film, sawdust and quadrupled layer bubble sheet based on heat enclosure installment. Test results showed that by applying both heating coil and bubble sheet and heat enclosure, the concrete exposed to $-20^{\circ}C$ can be effectively protected from early-age frost damage.

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A study on the growth and electrical-optical characteristics of undoped-InSe and Sn-doped Inse single crystals by vertical bridgman method (수직 Bridgman법에 의한 InSe 단결정의 성장 및 Sn 도핑에 따른 전기.광학적 특성에 관한 연구)

  • 정희준;송필근;문동찬;김선태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.481-484
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    • 1999
  • The undoped-InSe and Sn-doped InSe single crystals were grown by vertical Bridgman method and their properties were invesigated. These crystals were obtained by lowering the quartz ampoule for growth in the furnace and growth rate at optimum condition is 0.4mm/hr. The orientations and the crystallinites of these crystals were identified by X-ray diffraction(XRD), double crystal rocking curve(DCRC) and etch-pit density(EPD) measurements. From the Raman spectrum at room temperature, TO, LO modes together with their overtones and combinations were observed. Optical properties were investigated by photoluminescence at 12K and direct band gap of these crystals obtained from optical absorption spectrum. Compared with undoped-lnSe, electrical properties of Sn-doped InSe were increased and the electrical conductivity type were n-type. But electrical properties along growth direction of crystals and radial direction of wafer showed nearly uniform distribution.

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High-power fiber laser cutting parameter optimization for nuclear Decommissioning

  • Lopez, Ana Beatriz;Assuncao, Eurico;Quintino, Luisa;Blackburn, Jonathan;Khan, Ali
    • Nuclear Engineering and Technology
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    • v.49 no.4
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    • pp.865-872
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    • 2017
  • For more than 10 years, the laser process has been studied for dismantling work; however, relatively few research works have addressed the effect of high-power fiber laser cutting for thick sections. Since in the nuclear sector, a significant quantity of thick material is required to be cut, this study aims to improve the reliability of laser cutting for such work and indicates guidelines to optimize the cutting procedure, in particular, nozzle combinations (standoff distance and focus position), to minimize waste material. The results obtained show the performance levels that can be reached with 10 kW fiber lasers, using which it is possible to obtain narrower kerfs than those found in published results obtained with other lasers. Nonetheless, fiber lasers appear to show the same effects as those of $CO_2$ and ND:YAG lasers. Thus, the main factor that affects the kerf width is the focal position, which means that minimum laser spot diameters are advised for smaller kerf widths.

A study on the growth of undoped-lnSe single crystal by vertical Bridgman method and Zn diffusion in Sn-doped InSe (수직 Bridgman법에 의한 InSe 단결정의 성장 및 Sn이 첨가된 InSe에서 Zn의 확산에 잔한 연구)

  • 정회준;문동찬;김선태
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.464-467
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    • 1999
  • The undoped-InSe and Sn-doped InSe single crystals were grown by vertical Bridgman method and their properties were invesigated. The orientations and the crystallinites of these crystals were identified by X-ray diffraction(XRD), double crystal rocking curve(DCRC) and etch-pit density(EPD) measurements. From the Raman spectrum at room temperature, TO, LO modes and together with their overtones and combinations were observed. Optical properties were inves ated by PL at 12K and direct band gap of these crystals obtained from optical absorption spectrum. Compared with undo&-InSe, electrical properties of Sn-doped InSe were increased and the electrical conductivity type were n-type. But electrical properties along growth direction of crystals and radial direction of wafer showed nearly uniform distribution. The Zn diffusion mechanism in InSe could be explained by interstitial-substitutional and vacancy complex models and the activation energy of 1.15-3.01eV were needed for diffusion.fusion.

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Compatibility of POSS Composites with Silicone Monomers and Application to Contact Lenses Material

  • Lee, Min-Jae;Lee, Kyungmun;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.64 no.6
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    • pp.354-359
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    • 2020
  • This research was conducted to analyze the compatibility of used monomers and produce the high functional contact lens material containing silicone monomers. Silicone monomer (Sil-OH), Trimethylsilylmethacrylate (TSMA) were used as additives for the basic combination of Polyhedral Oligomeric Silsesquioxane (POSS), methyl methacrylate (MMA) and methyl acrylate (MA). And also, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the fabricated lenses of all combinations are optically excellent and thus used monomers have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic lens material were varied in each case. Especially TSMA with POSS increases the oxygen permeability and Sil-OH with POSS increases the wettability by the addition of Sil-OH. These materials were considered to have compatibility each other, so it can be used in functional contact lens material.

Feasibility of Composting Combinations of Sewage Sludge, Cattle Manure, and Sawdust in a Rotary Drum Reactor

  • Nayak, Ashish Kumar;Kalamdhad, Ajay S.
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.47-57
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    • 2014
  • The aim of this paper was to study the effect of five different waste combinations (C/N 15, C/N 20, C/N 25, C/N 30, and control) of sewage sludge coupled with sawdust and cattle manure in a pilot scale rotary drum reactor, during 20 days of the composting process. Our results showed that C/N 30 possesses a higher temperature regime with higher % reduction in moisture content, total organic carbon, soluble biochemical oxygen demand and chemical oxygen demand; and higher % gain in total nitrogen and phosphorus at the end of the composting period implying the total amount of biodegradable organic material is stabilized. In addition, $CO_2$ evolution and oxygen uptake rate decreased during the process, reflecting the stable behavior of the final compost. A Solvita maturity index of 8 indicated that the compost was stable and ready for usage as a soil conditioner. The results indicated that composting can be an alternate technology for the management of sewage sludge disposal.

A Study on Fashion Designing Idea (의상디자인 발상법에 관한 연구)

  • 조진숙;한명숙
    • The Research Journal of the Costume Culture
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    • v.8 no.4
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    • pp.537-548
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    • 2000
  • This paper focuses on development of a fashion design education course that will foster the talent and aesthetic consciousness of fashion design student. The writer reached the content of the designing ideas to practical applications as the defined scope of fashion design education. For designing idea in practical application : matching ideas, contrasting ideas, formative combinations and revisionism were used. For design ideas, the ideas developed by 飯塚弘子, 万江入重子, 香川達子 were used in revision. To detail the content of design education, fashion magazines, portfolios, photographs and related fashion design educational materials were used. 1. Matching ideas : it proposes such identical expression into costume by making a research of developing material, application form and color extraction from design sources. 2. Contrasting ideas : it proposes such opposite expression into costume by making a research of opposite to image, form, position and purpose from some object. 3. Formative combinations : it proposes such new expression into costume by combining a detail of costume with the other object. 4. Revisionism : it proposes such modified expression into costume by making a research of deletion, change, addition and conversion in costume.

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