• Proceedings of the KSME Conference
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• 2003.04a
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• pp.717-722
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• 2003

To improve the shock resistance of the microdrive under non-operating conditions, an isolator was attached to the contacting part of the microdrive. Through FE analysis, design parameters for satisfying the allowable acceleration level of the spindle motor bearing part were presented, which is a most possible critical part of the microdrive.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.215-219
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• 2012

Although the antioxidant capacity of carotenoids and their role in regulating membrane fluidity have been well studied, their ability to confer resistance to hypoosmotic shock is poorly understood. In this work, we analyzed the effect of a mixture of carotenoid pigments obtained from an Antarctic microorganism belonging to the genus Pedobacter on liposomal resistance to hypoosmotic conditions. Intercalation of pigments into liposomal structures resulted in an improvement of membrane resistance by decreasing the percentage of calcein released in comparison to that by liposomes without pigments. Due to these properties, such pigments could be useful for biotechnological applications.

• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.441-448
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• 2009

Magnesia partially stabilized zirconia(Mg-PSZ) solid electrolytes for an improvement of thermal shock resistance, which is suitable for the measurement of oxygen activity in a molten steel, were prepared by post-thermal aging treatment. The steelmaking oxygen sensor elements were formed by an injection molding method, sintered at $1650^{\circ}C$, and then thermal aged ranged from 1250 to $1400^{\circ}C$. Sintered density and porosity were decreased as increasing the magnesia content in a zirconia-magnesia solid solution. Fractions of cubic phase to the synthesized Mg-PSZ solid electrolytes were ranged from 13.13 to 79.54.% after post-thermal aging treatment. Very dense microstructure without voids in the grains was obtained by the post-thermal aging process. Fine tetragonal phase crystallites precipitated on the cubic surface during post-thermal aging up to $1300^{\circ}C$ improve a thermal shock resistance and reappearance of electro motive force(EMF) curve.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1581-1583
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• 1999

Epoxy Compound has been used as insulation material in cable accessories. During the applying voltage to cable, heat shock is induced to accessory by the temperature difference between atmosphere and conductor. In this study, crack resistance, thermal and mechanical properties were evaluated about conventional epoxy compound and rubber toughened epoxy compound. Because rubber absorbs the stress caused by heat shock, crack resistance of rubber toughened epoxy compound is high. In the case of low thermal expansion coefficient, the compound shows high crack resistance because of low volumetric change.

• Journal of the Korean Ceramic Society
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• v.35 no.6
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• pp.610-618
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• 1998

Alumina were added to ceria based ceramic powders upto 9.7 vol% and composite powders were sprayed by plasma spraying process in order to improve the mechanical properties such as hardness fracture tough-ness and thermal shock resistance. The ceria based coating sprayed without alumina has the typical colum-nar and lamellar structure. Alumina addition has lowered the amount of columnar and lamellar sturcture Added alumina was segreagated in the grain boundary and grain of ceria based crystal accompanied with pore. The maximum value of density and the minimum value of porosity were observed at the sprayed coating with 4.8 vol% alumina. The hardness fracture toughness and thermal shock resistance were increased with alumina addition. The improvement of mechanical properties of plasma sparyed ceria based coatings result-ed from the disapperance of the columnar and lamellar sturcture by addition of alumina.

• International Journal of Concrete Structures and Materials
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• v.3 no.2
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• pp.97-101
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• 2009

It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18${\sim}$20%), low strength and insufficient water resistance. Therefore they can not be used as materials for load-bearing structural elements. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block of superficial pores and reduces concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. This effect is attributable to hardening of contacts between silicate binder gel globes and modification of alkaline component owing to "inoculation" of the furan radical. The optimal concrete composition with the increased strength, chemical resistance in the aggressive environments, density and crack resistance was obtained.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.477-482
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• 2001

To realize higher track density of HDD, the servo bandwidth should be higher, however, is limited by the mechanical resonances of the arm, coil of the VCM and ball bearing pivot. The dual-stage actuator systems have been suggested as a possible solution. For the dual-stage actuator systems based on the suspension, the suspension resonance frequencies in the radial access direction are important factors to increase a servo bandwidth, however the improvement of these frequencies may affect the shock resistance performance and spring constant. The slider's flying stability can be deteriorated by the change of a vertical stiffness. In this work, we have investigated a suspension design scheme possessing a milliactuator for dual-stage actuator systems and also achieved higher mechanical characteristics. Design parameters are deduced by finite element analysis with sensitivity function. It is confirmed that the proposed suspension with the milliactuator has the capability of fine tracking motion, due to its hinge structure on the spring region, and achieves higher mechanical resonance frequencies in the radial access direction with a high-shock resistance and a low-spring constant.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.55-62
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• 2017

The grate bar, a component used in steel mills, is used in harsh environments where external disturbances such as high temperature, abrasion, corrosion, and impacts are present. Therefore, in this study, spray-coating was performed on the most severely affected surface to extend the lifetime of the grate bar. The thermal and mechanical properties of the sprayed coated bars were investigated based on the performances under abrasion, thermal shock, tension, and sand blasting, and the microstructures by microscope. By analyzing the thermal and mechanical properties of the uncoated original grate bar and coated grate bar and comparing them with one another, the physical performance improvement of the coated grate bar can be verified.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.67-73
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• 2016

The degradation behaviors of TiN coating layers under thermo-mechanical stress were investigated in terms of comparison of finite element analysis (FEA) and experimental data. The coating specimen was designed to quarter cylinder model, and the pulsed laser ablation was assumed as heat flux condition. The FEA results showed that heat accumulation at the center of the laser-ablated spot occurred and principle stress was concentrated at the lower region of the coating layer. The microstructural observation revealed that surface melting and decrease of the coating thickness occurred in the TiN/Inconel 617 and the interfacial cracks formed in the TiN/Si. The delamination was caused by the mechanical stress from the center to the outside of the ablated spot as the FEA results expected. It was considered that the improvement of the thermal shock resistance was attributed to higher thermal conductivity of Si wafer than that of Inconel 617.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.78-85
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• 2006

A person's body resistance in the waterpark, public bath and similar places is much lower than any other places due to effect of water. So low voltage may create a shock hazard for the human body in case of leakage or fault currents from lighting unit etc. We researched the related regulations which are internal standards, NEC, IEC and investigated the actual conditions for the prevention of electric shock due to lighting units in the waterpark, public bath and similar places. As a results internal standard is obscure as compared with NEC, IEC which is the limit of application and distinction of environment condition. And then internal standard's using voltage is higher than NEC, IEC in filed of water. Studies show that internal standard should be revision that raise the installation height of lighting unit, mark IP level surface of lighting unit and limit using voltage to line-to-line voltage