• 제목/요약/키워드: surface characterization

검색결과 2,091건 처리시간 0.084초

LED 검사장비용 탐침의 특성 규명 (Characterization of Probe Pin for LED Inspection System)

  • 심희수;김선경
    • 한국생산제조학회지
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    • 제24권6호
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    • pp.647-652
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    • 2015
  • A probe pin is a key component of LED inspection equipment. The probe pin makes contact with the LED electrodes and supplies an electric current. Because the mechanical and electrical homogeneity of the probe surface affects the service life and reliability, its characterization is essential. For this study, the hardness was measured using a micro-Vickers hardness test. Moreover, the thicknesses of the plating at different locations and the elemental compositions were examined using an FE-SEM. The uniformity of the plating was found to be acceptable because palladium was detected consistently throughout the tested domain. In addition, the hardness of the surface was determined to be higher than that of the typical palladium range, which is attributed to the use of undercoated nickel.

Peculiarities of gas sensing characteristics of SnO2-based sensors modified by SnO2-Au nanocomposites synthesized by SILD method

  • Korotcenkov, Ghenadii;Cho, Beong-Ki;Tolstoy, Valery;Gulina, Larisa B.;Han, Sang-Do
    • 센서학회지
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    • 제18권6호
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    • pp.417-422
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    • 2009
  • The problems associated with the synthesis, characterization and application of $SnO_2$-Au nanocomposites for the optimization of conductometric gas sensors have been discussed in this report. Nanocomposites have been synthesized on the surface of $SnO_2$ films using successive ionic layer deposition(SILD) method. It has been shown that the proposed approach to surface modification of metal oxide films is an excellent method for the optimization of the operating characteristics of $SnO_2$-based gas sensors, being developed for the detection of reducing gases as well as ozone.

플라즈마 용사법에 의한 $Al_2$O$_3$ 피복층의 열처리효과에 관한 연구 (The Heat Treatment Characterization of Plasma Sprayed Alumina Coatings)

  • 오익현;김한산;김수식
    • 한국표면공학회지
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    • 제27권3호
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    • pp.134-142
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    • 1994
  • $Al_2O_3$coatings on mild steel substrate by plasma spray process were produced to evaluate microstructural characterization and mechanical properties. As-coated $Al_2O_3$coating samplessd were subjected to two heat treat-ment conditions : ⅰ) annealing under vacuum circumstance, ⅱ) hot press treated condition. The two heat treat-ed coatings were investigated in terms of microhardness, adhesion strength, wear resistance, porosity forma-tion, and microstructures. In the case of the coatings which were subject to preparation step ⅰ, the porosity in the coating was decreased with the increase of temperature ($700^{\circ}C$-$1100^{\circ}C$), and the wear resistance, microhardnesss and adhesion strength were increased with the increase of temperature. On the other hand, in the case of the coatings which were subject to preparation step ⅱ, wear resistance and adhesion strength were improved with the increase of temperature and pressure. Experimental measurements of coatings which were produced by both preparation conditions were enhanced compare to those of as-coated coatings.

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FT-IR Spectroscopic Characterization of Oxidized and Reduced Titania

  • Kim, Kwan
    • Bulletin of the Korean Chemical Society
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    • 제11권5호
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    • pp.396-399
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    • 1990
  • Fourier transform infrared spectroscopy has been applied to the characterization of titania surface. The bands due to surface OH groups were observed to be more intense in the reduced titania than in the oxidized titania. The IR spectra of CO adsorbed on titania exhibited two C-O stretching bands, namely at 2187 and 2209 cm$^{-1}$. The intensities were stronger in the oxidized titania.The 2187 cm$^{-1}$-peak was attributed to CO coordinated to $Ti^{4+}_{5c}$ (subscriptindicates the coordination number of the coordinatively unsaturated cation by oxygen ions), while the 2209 cm-1-peak due to the $Ti^{4+}_{4c}{\cdots}$CO complex.

Microscopical and chemical surface characterization of CAD/CAM zircona abutments after different cleaning procedures. A qualitative analysis

  • Gehrke, Peter;Tabellion, Astrid;Fischer, Carsten
    • The Journal of Advanced Prosthodontics
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    • 제7권2호
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    • pp.151-159
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    • 2015
  • PURPOSE. To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS. A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non- quantitatively. RESULTS. All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION. The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.