• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.784-787
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• 2003

In this study, water jet etching of aqueous green tape was attempted for processing barrier rib of plasma display panel. This process combines 1) chemical etching between water and aqueous based binder in the tape and 2) mechanical erosion by water jet. Effects of etching parameters such as pressure, temperature and aqueous binder content on the morphology of barrier ribs formed were investigated. The results demonstrated a possibility of processing barrier ribs by water jet etching.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2076-2081
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• 2008

In this study, a new concept of a flow sensor is developed using dielectric barrier discharge (DBD). Current of DBD generated between two electrodes is changed with varying flow rates. Therefore, it is possible to measure the flow rate by correlating generated DBD current with flow rates. The effects of flow rate, frequency, channel height, diameter of electrodes and distance between electrodes on the performance of the flow sensor using DBD are experimentally investigated.

• Journal of the Korean Ceramic Society
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• v.54 no.4
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• pp.314-322
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• 2017

This study investigates changes in the mechanical behavior, such as changes in indentation load-displacement curve, wear resistance and contact fatigue resistance of thermal barrier coatings (TBCs) by thermal cycling test and thermal shock test. Relatively dense and porous TBCs on nickel-based bondcoat/superalloy are prepared; the highest temperature applied during thermal durability test is $1350^{\circ}C$. The results indicate that the porous TBCs have relatively longer lifetime during thermal cycling and thermal shock tests, while denser TBCs have relatively higher wear and contact fatigue resistance. The mechanical behavior is influenced by sintering of the TBCs by exposure to high temperature during tests.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.3
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• pp.37-41
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• 2012

The wafer level stacking with Cu-to-Cu bonding becomes an important technology for high density DRAM stacking, high performance logic stacking, or heterogeneous chip stacking. Cu CMP becomes one of key processes to be developed for optimized Cu bonding process. For the ultra low-k dielectrics used in the advanced logic applications, Ti barrier has been preferred due to its good compatibility with porous ultra low-K dielectrics. But since Ti is electrochemically reactive to Cu CMP slurries, it leads to a new challenge to Cu CMP. In this study Ti barrier/Cu interconnection structure has been investigated for the wafer level 3D integration. Cu CMP wafers have been fabricated by a damascene process and two types of slurry were compared. The slurry selectivity to $SiO_2$ and Ti and removal rate were measured. The effect of metal line width and metal density were evaluated.

• Tunnel and Underground Space
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• v.17 no.6
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• pp.464-474
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• 2007

An enhancement in the performance and safety of a high-level waste repository requires a validation of its engineered barrier. An engineering-scale test (named "KENTEX") has been conducted to investigate the thermal-hydro-mechanical behaviors in the engineered barrier of the Korean reference disposal system The validation test started on May 31, 2005 and is still under operation. The experimental data obtained allowed a preliminary and qualitative interpretation of the thermal-hydro-mechanical behaviors in the bentonite blocks. The temperature was higher as it became closer to the heater, while it became lower as it was farther away from the heater. The water content had a higher value in the part close to the hydration surface than that in the heater part. The relative humidity data suggested that a hydration of the bentonite blocks might occur by different drying-wetting processes, depending on their position. The total pressure was continuously increased by the evolution of the saturation front in the bentonite blocks and thereby the swelling pressure. Near the heater region, there was also a significant contribution of the thermal expansion of bentonite and the vapor pressure in the pores of the bentonite blocks.

• Journal of the Korean Society of Visualization
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• v.15 no.2
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• pp.59-67
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• 2017

To verify floatability of ABB (Air bubble barrier), we compared bubble swarm behavior with and without the air-driven ejector. Experiment was conducted using the fabricated air-driven ejector with 5 mm nozzle on the bottom of 1 m3 water tank. Reynolds number of air in the nozzle was ranged 1766-13248. We analyzed data with statistical method using image processing, particle mage velocimetry (PIV) and proper orthogonal decomposition (POD) analysis. As a result of POD analysis, there was no significant eigenmode in bubbly flow generated from the ejector. It means that more complex turbulent flows were formed by the ejector, thereby (1) making bubbles finer, (2) promoting three-dimensional energy transfer between bubble and water, and (3) making evenly distributed velocity profile of water. It is concluded that the air-driven ejector could enhance the performance of ABB.

• Journal of the Korean Society of Visualization
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• v.15 no.2
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• pp.48-58
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• 2017

To analyze bubbles generated by an ABB (Air Bubble Barrier), we developed image processing procedure and statistical analysis method. Air was discharged from 5 mm nozzle as swarm form at the bottom of 1 m3 water tank. Flow rates of discharged air are ranged from 2 L/min to 20 L/min and these are corresponding to Reynolds number of 1766-17663. Rise velocity of bubble is extracted by using image process pretending intrusive method. Mean equivalent velocity was calculated using void fraction weighting factor. Bubble diameter is obtained and compared with correlations in the literature. Also, we present a correlation according to the result of this study. Mean velocity and mean diameter of bubbles increase with increasing gas Reynolds number. But these parameters show an asymptotic trend when they approach to high Reynolds number.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.7
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• pp.91-98
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• 2009

A reliable tensile test technique for PDP's barrier rib materials was introduced. A tensile specimen was prepared by punching out of green sheet, curing the specimen in a high temperature furnace, attaching sand paper tabs on each grip ends, and then attaching two strain gages for the strain monitoring and specimen alignment. Preliminary tensile tests were successfully done with the specimens made from ZnO-based lead-free green sheet. The specimens cured at 3 different maximum curing temperatures were tested to demonstrate the applicability of the test method. The Young's modulus was 88 ${\pm}$ 4 GPa regardless of the maximum curing temperature. The ultimate tensile strength was decreased with increasing the temperature. The tensile test method proposed in this study was proven to be reliable, useful and easy to estimate the bulk mechanical properties of barrier rib materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.4
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• pp.475-480
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• 2010

The thermal barrier coating of a gas turbine blade was degraded by isothermal heating in a furnace and by varying the exposure time and temperature. Then, a micro-Vickers hardness test was conducted on the cross section of the bond coat and Ni-based superalloy substrate. Further, the thickness of TGO(Thermally Grown Oxide) was measured by using an image analyzer, and the changes in the microstructure and element contents in the coating were analyzed by using an optical microscope and by performing SEM-EDX analysis. No significant change was observed in the Vickers hardness of the bond coat when the coated specimen was degraded at a high temperature; delamination was observed between the top coat and the bond coat when the coating was degraded for 50 h at a temperature $1,151^{\circ}C$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.71-77
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• 2023

Absorbable periodontal tissue regeneration barrier membranes (total 6; domestic 4; import 2) were comparatively analyzed. In the case of the xenograft barrier membrane, the collagen product had excellent tensile strength but low strain, and the porcine pericardial membrane had good mechanical properties, but its thickness was too thick to control. The synthetic PLLA membrane manufactured by the electrospinning had a relatively low water absorption capacity. However, the hybrid barrier membrane was able to control mechanical properties and biocompatibility through proper mixing of synthetic polymer and natural polymer. DA02 (PLLA/gelatin), a newly developed hybrid absorbable periodontal tissue regeneration membrane that is entirely dependent on imports, can be applied to an absorbable periodontal tissue regeneration barrier membrane due to suitable mechanical properties and biocompatibility.