• 제목/요약/키워드: practical surface

검색결과 1,221건 처리시간 0.025초

거푸집 붙임재료에 따른 노출콘크리트 시공에 관한 연구 (Study on the Exposed Concrete Construction Formwork According to Attachment Materials)

  • 박세준;이윤석;이영도
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.223-224
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    • 2016
  • Recent local advantages to improve the aesthetics of building materials connected with one of the trend of Exposed Concrete and Construction Method in various facilities and to diversify Showing a tendency to both application and development. This exposed concrete form of the features and materials is, the impact of large commercial viability and can consider I can apply to the surface of construction on a surface The diversification of the material was soon exposed directly linked to the varying aesthetics of concrete, and currently take advantage of the form of material is based on such important factor in our country Based on the concept of Exposed Concrete utilized by some construction site, design and be considered is very important elements of the put to practical use.

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Biocompatible Nanoparticles with Well-defined Surface Chemistry for Smart Drug Delivery

  • Min, Dal-Hee
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.107-107
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    • 2013
  • Many nanomaterials are being harnessed as critical components in various systems for biomedical applications including diagnosis, imaging, and drug delivery. Those systems necessitate biocompatibility and low toxcity within effective dose range while achieving enough efficacy. Even though many nanomaterials enjoy successful demonstrations in bioapplications, lack of biocompatibility and high cytotoxicity often become hurdles for practical bioapplications. On the other hand, it is important to achieve enough efficiency based on chemically well-defined systems with efforts to understand mechanism at molecular level. Here, we developvarious biocompatible nanomaterials based on simple procedure using dextran as both reducing agent and surface coating. Dextran is one of the popular biocompatible polymers that have been used for drug delivery and biosensors. Dextran coated nanomaterials showed excellent colloidal stability, flexible surface chemistry for conjugation of bioactive molecules and low cytotoxicity with successful demonstrations in various bioapplications.

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하트만 방법에 의한 광학면의 기상측정 (On-Machine Measurement of an Optical Surface by Hartmann Test)

  • 김용관;오창진;이응석;김옥현
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.474-480
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    • 2002
  • Aspheric optical lenses and mirrors are widely used in recent. It is more difficult to manufacture and measure the aspherical optics compared to conventional spherical ones. The interferometric optical test is common for the measurement of spherical optical surface. But the application of the interferometry to the measurement of aspheric surface is difficult because it needs a precise null corrector and very careful environmental conditions such as keeping constant temperature, humidity, atmospheric pressure and vibrations. To enhance productivity of optics manufacturing on-machine measurement and correction has been developed in this study. For practical applications, robustness of the measurement method to environments is more important. For the purpose an optical OMM(On-Machine Measurement) system has been developed using Shack-Hartmann test which has robustness to the environment. The wavefront has been reconstructed from the measured data using the primary aberration polynomial function by least square fitting. The measured result of the developed only system gives the maximum deviation only in 200 nm from the result measured by a commercial Fizeau interferometer Wyko 6000.

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Surface magnetic properties of annealed $Co_{66}Fe_4B_{15}Si_{15}$ amorphous ribbons

  • L. Jin;Y. W. Rheem;Lee, B. S.;Kim, C. G.;Kim, C. O.
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2002년도 동계연구발표회 논문개요집
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    • pp.208-209
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    • 2002
  • Recently an asymmetric giant magnetoimpedance (GMI) profile has been observed in Co-based amorphous ribbons annealed at the weak field [1-4]. This phenomenon has attracted a large interest due to its practical application to sensitive magnetic sensors. It is known [5.6] that in magnetic materials, the magnetoimpedance is caused by the effect of the magnetic field on the transverse magnetic permeability of a near-surface layer. In consequence of it, the value of the magnetoimpedance depends strongly on near-surface magnetic properties of the sample. (omitted)

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Application of Coanda Effects to a Ship Hydrofoil

  • Oh, Jung-Keun;Ahn, Hae-Seong;Kim, Hyo-Chul;Lee, Seung-Hee;Lew, Jae-Moon
    • Journal of Ship and Ocean Technology
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    • 제7권2호
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    • pp.29-39
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    • 2003
  • A Coanda foil is a high-lift generating device exploiting the phenomena that flow separation is delayed if a high-speed jet is applied tangential to the surface as well known to the aerodynamic fields. In the present study, a Coanda foil with a flap is investigated to seek the possibility of marine application. Model experiments are carried out both in a towing tank and cavitation tunnel and surface pressure distributions, forces and moments acting on the foil are measured at the various angle of attacks and flap angles. The results are also compared to the numerical ones to show good agreements. The results of the present study demonstrate the practical applicability of the Coanda foil in the design of ship control surfaces.

A Study on Development of Advanced Environmental-Resistant Materials Using Metal Ion Processing

  • Fujita Kazuhisa;Kim Hae-Ji
    • Journal of Mechanical Science and Technology
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    • 제20권10호
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    • pp.1670-1679
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    • 2006
  • The development of the oxidation, wear and corrosion resistant materials that could be used in severe environmental conditions is needed. The elementary technologies for surface modification include ion implantation and/or thin film coating. Furthermore, in order to develop ion implantation technique to the specimens with three-dimensional shapes, plasma-based ion implantation (PBII) techniques were investigated. As a result, it was found that the ion implantation and/or thin film coating used in this study were/was effective for improving the properties of materials, which include implantations of various kinds of ions into TiAl alloy, TiN films formed on surface of base material and coatings in high-temperature steam. The techniques proposed in this study provide useful information for all of the material systems required to use at elevated temperature. For the practical applications, several results will be presented along with laboratory test results.

3 T급 대면적 YBCO 초전도 벌크자석 개발 (Development of 3 T-class Large Area YBCO Superconductor Bulk Magnet)

  • 한상철;정세용;박병준;한영희
    • Progress in Superconductivity
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    • 제14권1호
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    • pp.71-75
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    • 2012
  • For the practical application of a YBCO superconductor bulk magnet, the superconductor bulk magnet with strong and stable magnetic field on a large area surface should be fabricated. To satisfy these requirements, we have designed a conduction-cooled bulk magnet system using six single grain YBCO bulk superconductors. Six rectangular-shaped YBCO bulk superconductors with a dimension of $38{\times}38{\times}15mm^3$ were field-cooled at 20 K using a superconductor magnet with maximum operating magnetic field of 4 T. The magnetic flux of 3.0 T and 2.8 T were achieved on the surface of bulk superconductors and over the vacuum chamber surface of the refrigerator, respectively.

Angle Beam Ultrasonic Testing Models and Their Application to Identification and Sizing of Surface Breaking Vertical Cracks

  • Song, Sung-Jin;Kim, Hak-Joon;Jung, Hee-Jun;Kim, Young-H.
    • 비파괴검사학회지
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    • 제22권6호
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    • pp.627-636
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    • 2002
  • Identification and sizing of surface breaking vertical cracks using angle beam ultrasonic testing in practical situation quite often become very difficult tasks due to the presence of non-relevant signals caused by geometric reflectors. The present work introduces effective and systematic approaches to take care of such a difficulty by use oi angle beam ultrasonic testing models that can predict the expected signals from various targets very accurately. Specifically, the model-based TIFD (Technique for Identification of Flaw signals using Deconvolution) is Proposed for the identification of the crack tip signals from the non-relevant geometric reflection signals. In addition, the model-based Size-Amplitude Curve is introduced for the reliable sizing of surface breaking vertical cracks.

표면장력 효과를 고려한 이상유동 해석법 개선에 관한 연구 (Study on Improvement in Numerical Method for Two-phase Flows Including Surface Tension Effects)

  • 박일룡
    • 한국해양공학회지
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    • 제27권5호
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    • pp.70-76
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    • 2013
  • The present paper proposes a coupled volume-of-fluid (VOF) and level-set (LS) method for simulating incompressible two-phase flows that include surface tension effects. The interface of two fluids and its motion are represented by a VOF method designed using high-resolution differencing schemes. This hybrid method couples the VOF method with an LS distancing algorithm in an explicit way to improve the calculation of the normal and curvature of the interface. It is developed based on a rather simple algorithm to be efficient for various practical applications. The accuracy and convergence properties of the method are verified in a simulation of a single gas bubble rising in a three-dimensional flow with a large density ratio.

직렬 배열된 두 기포의 bursting jet에 대한 수치적 연구 (Numerical Study of Bursting Jet in Two Tandem Bubbles)

  • 이창걸;이선엽;;이재화
    • 한국가시화정보학회지
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    • 제18권3호
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    • pp.52-60
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    • 2020
  • When a bubble reaches a free surface, a bursting of the bubble produces a high speed jet. Despite its practical importance, significant effort has been devoted to investigate a bursting jet by a single bubble near a free surface. In the present study, we perform numerical simulations of bubbles in a tandem arrangement at Bo=0.05. The configuration of the tandem bubbles is systematically varied by changing a radius of a following bubble (RF) and the gap distance between two bubbles (L). Compared to a single bubble case, we show that the bursting bubble in the tandem arrangement accelerates, and the jet velocity increases. Moreover, we find that a critical gap distance at which the jet velocity unexpectedly changes exists in the tandem case.