• 한국산학기술학회논문지
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• 제18권12호
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• pp.118-125
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• 2017

본 논문은 FRP Hybrid Bar의 최적 부착 성능 도출을 위한 실험 결과를 나타낸다. FRP Hybrid Bar는 이형 철근의 부식문제를 해결하기 위하여 이형 철근 외측에 유리섬유를 감싸 만들어졌다. 콘크리트와의 부착 성능 향상을 위해 매끈한 FRP Hybrid Bar 표면에 수지와 규사를 이용하여 코팅하였고 수지의 종류 및 점도, 그리고 규사의 크기를 실험 변수로 하여 FRP Hybrid Bar의 부착 성능을 실험적으로 평가하였다. FRP Hybrid Bar의 부착 성능 평가를 위해 한 변의 길이가 200 mm인 정육면체 콘크리트 블록에 FRP Hybrid Bar를 매립하였고, 인발 실험을 통하여 FRP Hybrid Bar와 콘크리트의 계면에서의 최대 하중과 슬립을 측정하였다. 실험 결과로부터, 각 실험 변수에 따른 최대 하중 및 부착 강도를 산정하였고 FRP Hybrid Bar의 부착 성능이 가장 우수한 수지 종류 및 점도, 그리고 규사 크기를 도출하였다. 에폭시 수지와 5호 규사를 사용한 실험체의 최대부착강도는 이형철근의 최대부착강도 대비 약 35% 정도 증가되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.204-209
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• 1995

The influence of the interfacial properties on the bond capacity of reinforcing bars to concrete is studied in this paper. In this study, the deterioration of the interfacial bond capacity when top-cast bars or epoxy-coated bars are used is examined. The effect of such variables on bond capacity in reinforced concrete is studied by experiment which use beam-end specimens. The main objective of this study is that comparing the test results and the requirements in ACI 318-89 code. the verification of the factor in ACI code is also presented in this paper. The results of the test show that "top bar effect" is considerably affected by the slump of fresh concrete, so the influence of slump shoud be taken into account for top bar effect factor in code. Test results also shows that the bond-slip curve of the epoxy-caoted bars is similiar to that of the uncoated and bond strength is reduced about 15% and that coating thickness seems to influence the bond strength deterioration.rioration.

• 한국디지털건축인테리어학회논문집
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• 제8권1호
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• pp.57-64
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• 2008

There are many problems in present truss-deck slab system for example welding defect, segregation, water leakage, rust and tarnish etc. These problems may be caused by spot welding thin galvanized steel plate and lattice bar. The TOX Joining Systems is to join metal sheets of different material and thickness with and without coating or painting without adding heat or a joining part. Newly developed TOX-deck slab system using non-welding joint is free from above mentioned problems. The objects of this study are suggestion of design strength of TOX joint by experimental and statistical analyses and development of window based program to design the TOX-deck slab system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.58.2-58.2
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• 2010

This paper deals with the simulation of solid particle coating technology via supersonic nozzle in vacuum environment to devote as an aerosol-deposition device. In order to improve efficiencies of nozzle and coating process, effects of shockwave, nozzle geometry, and substrate location were studied computationally under a fixed chamber pressure of 0.01316 bar which is nearly vacuous. Shockwave is the important factor affect to entire flow because shockwave in the jet flow dissipates the kinetic energy of the flow in the supersonic condition. Results show that various nozzle geometries have significant effect on the supersonic flow and we know that the supersonic nozzle should be optimized to minimize the loss of the flow. Another parameter, the distance between substrate and nozzle tip, shows little effect in this study.

• 설비공학논문집
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• 제16권5호
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• pp.430-437
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• 2004

This paper is intended as an investigation of study on the thermal and electrical characteristics of the carbon heating element. In this experimentation, the electric material used is the crystalline graphite a kind of natural graphite. The bentonite is used to solidify the heating element and the vacuum furnace is used for sintering it. It is noted that the natural drying time should be at least 58 hours. The plating of the electric pole with the electroless nickel showed the lowest contact resistance among others. The resistance shows linear variation with regard to length. For the insulation and resolution, the glaze coating is best with 80% of water content. The temperature rising characteristic of the heating element is better than sheath heater saving 43% of rising time. The correlation equation for temperature was obtained with the electric power.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.343-348
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• 2000

The purpose of this study is to clarify properties adhesive strength of polymer-cement slurry for coated reinforcing bars. The epoxy coating material is superior to performance of anti-corrosion but lately age adhesive strength between concrete raise to structural problems. However, polymer dispersion with excellent performance of elasticity and adhesion can solve this problems. From the test results. adhesion of steel with polymer cement slurry using St/BA emulsion is show excellent without concerned coating thickness, and polymer cement slurry using St/BA emulsion is show adhesion in tension 1.2~2.2MPa at polymer cement ratio 50% of more.

• 한국주조공학회지
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• 제20권4호
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• pp.247-253
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• 2000

Titanium was melted in the CaO-coated alumina crucible and the reaction between the melt and the coating layer was negligible. The volume fraction of the gas porosity was decreased with increasing pressure and the sound bar castings with no porosity was obtained under the Ar atmosphere of the pressure of $300kN/mm^2$. The surface of the casting obtained from CaO-coated graphite mold was slightly rougher than that from graphite without coating. The reaction product of titanium melt with the layer of CaO was mainly titanium oxide and that with graphite crucible was titanium cabide with small amount of titanium nitride.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.157.2-157.2
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• 2016

Water repellent surfaces may enhance the condensation by efficiently removing the condensed droplets. However, such surfaces may lose their original performance as they are exposed to external mechanical stresses. In this work, we fabricated spray-coated mechanically robust superhydrophobic surfaces using treated titanium dioxide (Type 1) or silica particles (Type 2). Then we compared the mechanical robustness of such surfaces with the silane-coated superhydrophobic surface and PEEK coated surface using a controlled-sand blasting method. The results show that the spray-coated samples can maintain the same level of the contact angle hysteresis than silane-coated superhydorphobic surface after sand blasting at 2 bar. The spray-coating method was applied to the tube type condenser and the condensation behaviors were observed within the environmental chamber with controlled pressure, humidity and non-condensable gas. Previously-reported droplet jumping was observed in the early stage of the condensation event, but soon the droplet jumping stopped and only dropwise condensation was observed since the condensed droplets were pinned on the cracks at spray-coated surfaces. The static contact angle decreases from $158.0^{\circ}$ to $133.2^{\circ}$, and hysteresis increases from $3.0^{\circ}$ to $23.5^{\circ}$ when active condensation occurs on such surfaces. This work suggests the benefits and limitation of spray-coated superhydrophobic condensers and help develop advanced condensers for practical use.

• 한국세라믹학회지
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• 제33권6호
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• pp.700-708
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• 1996

TiO2 membranes for microfiltration were prepared on $\alpha$-alumina support tube by slurry coating. The coating layer was obtained by flowing TiO2 slip on the inner surface of the alumina support. TiO2 membranes were heat-treated at 9$25^{\circ}C$ for 2 hrs. The thickness of the unsupported membrane was about 10${\mu}{\textrm}{m}$. The mean pore diameter of the membranes were 0.09 and 0.15${\mu}{\textrm}{m}$ respectively and the pure water flux was 900~1,200ι/m2.hr at room temperature and 1 bar. For a possible application of oily wastewater treatement an kerosene/wa-ter emulsion was separated in terms of flux and removal efficiency. In 60 min of operating time the flux of TiO2 membranes was 50~100 ι/m2.hr and removal efficiency was over 97% at 3kgf/cm2 of operating pres-sure and 600 ml/min of flow rate. TiO2 membranes could be recycled by reheat treatments at $600^{\circ}C$ for 2 hrs.

• 한국전기전자재료학회논문지
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• 제22권3호
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• pp.248-251
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• 2009

We have investigated the effect of the quality of 1.3 um distributed feed back laser diode (DFB-LD) on the design of anti-reflection (AR) coatings. Optimal condition of AR coating to prevent internal feedback from both facets and reduce the reflection-induced intensity noise of laser diode was simulated with Macleod Simulator. Coating materials used in this work were ${Ti_3}{O_5}$ and $SiO_2$, of which design thickness were 105 nm and 165 nm, respectively. AR coating films were deposited by Ion-Assisted Deposition system. The electrical and optical properties of 1.3 um laser diode were characterized by Bar tester and Chip tester. Threshold current and slop-efficiency of DFB-LD were 27.56 mA 0.302 W/A. Far field pattern and wavelength of DFB-LD were $22.3^{\circ}(Horizontal){\times}24.4^{\circ}$ (Vertical), 1313.8 nm, respectively.