• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.175-191
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• 2016

The present article is aimed at an investigation of stresses produced in a microstretch elastic half-space due to a moving load. The expressions of normal stress, shear stress and tangential couple stress produced in this case have been obtained in closed form. To find the displacement fields the perturbation method is applied. Significant effect of moving load on variation of stresses developed at different depths below the surface due to the depth of substrate and frictional coefficient of the rough surface of the medium has been observed. The effects of different shapes of irregularity and depth of irregularity on normal, shear and tangential couple stresses have been discussed. Some particular cases have also been deduced from the present investigation. Finally, the analytical developments have been illustrated numerically for aluminium-epoxy-like material substrate under the action of moving load.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.3
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• pp.25-29
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• 2002

Single ion exchange process was used, and the ion exchange behavior and mechanical properties were investigated in substrate glass for flat panel display. In order to study the effects of ion exchange, ion exchange behavior with ion penetration depth, amount of ion exchange, density and thermal expansion was measured according to the time and temperature. The mechanical properties were evaluated by the three point bending test and curvature change, and then the fracture patterns were investigated by optical microscope.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.88-96
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• 1994

Hot filament-assisted CVD was carried out to deposit diamond films on Si(100) substrate at 90$0^{\circ}C$ using a 1% CH4-H2 mixture gas. Deposition was made at various conditions of mass flow rate of the feed gas (30~1000 sccm), pressure (2.5~300 Torr), and filament-substrate distance (4~15 mm), and the deposited films were characterized by SEM, XRD, and Raman spectroscopy. As the flow rate increases, the growth rate also increased but the crystallinity of the film was degraded. A longer filament-substrate distance simply caused both the growth rate and the crystallinity to become poorer. On the other hand, the pressure variation resulted in a maximum growth rate of 2.6 ${\mu}{\textrm}{m}$/hr at 10 Torr and the best film quality around 50 Torr, exhibiting an optimum condition. The observed trends were interpreted in terms of the flow velocity-dependent pyrolysis reaction efficiency and mass transport through the boundary layer.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.140-141
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• 2002

In proto-type microactuators driven by magnetostrictive Tb-Fe thin films, the deflection was observed to be much smaller than that expected from large-sized "standard" Tb-Fe thin films. A striking difference was observed when the results from a thin substrate of 28 $\mu\textrm{m}$ for microactuator applications were compared with those from a standard substrate. At a standard substrate thickness (several hundred $\mu\textrm{m}$), an amorphous phase was formed and the coercivity was low being 80 Oe. (omitted)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.877-880
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• 2000

The length extensional vibration mode of a piezoelectric ceramic substrate is used in fabricating the ultra-small size resonators and filters. In general, the three side ratios of the substrate effect the resonant characteristics of the resonator using its length extensional vibration. In this paper, their relationships are studied. We know that changing the ratio of its length to its width makes possible to change the resonant frequency of the width vibration without degrading the length extensional vibration.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.560-564
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• 2006

ZnO thin films were prepared by RF magnetron sputter deposition on p-Si(100) wafer with various cooling rates of substrate temperature such as the substrates were pre-heated to $400^{\circ}C$ before the deposition and then cooled down naturally or slowly to $300^{\circ}C,\;200^{\circ}C,\;100^{\circ}C$, and R.T. by the temperature controller during the deposition. Crystalline and micro-structural characteristics of the films were investigated by XRD and SEM. ZnO films which cooled down naturally or slowly by the temperature controller during the deposition, especially the film were deposited with cooling down from $400^{\circ}C\;to\;200^{\circ}C$ slowly. showed the most outstanding c-axis preferred orientation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.484-487
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• 2001

Amorphous carbon thin films were deposited using laser ablation technique on Si(100) substrates at different temperatures. In this study, effects of the substrate temperature on the properties of amorphous carbon films were systematically investigated. The surface morphologic and structural properties of the films were studied by scanning electron microscopy (SEM) and raman spectroscope, respectively. With increasing of the substrate temperature, the surface morphologies were changed singnificantly. Moreover the intensity ratio of D-band and G-band and the full width at half maximum of these bands were dependent on substrate temperatures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.303-303
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• 2007

Photo-imageable thick-film lithography technology was developed for the fabrication of embedded passives such as inductors and capacitors. In this study, photo-imageable dielectric and conductor pastes have apoted a negative type. Sodalime glass wafer, alumina substrate and zero-shrinkage LTCC green tapes were used as substrates. In result, The lithographic patterns were designed as lines and spaces for conductor material, or via-holes for ceramic, LTCC, materials. The scattering and reflection of UV-beam on the substrate had negative effects on fine patterning. The patterning performance was varied with the exposing and developing process conditions, and also varied with the substrate materials. Fine resolution of less then $50/50{\mu}m$ in line and space was obtained, which is difficult in screen printing method.

• Bulletin of the Korean Chemical Society
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• v.17 no.10
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• pp.905-908
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• 1996

A substrate specificity of cabbage phospholipase D (PLD) was studied using the synthetic phospholipids having different head groups. The phospholipids were synthesized from phosphatidylcholine and appropriate bases by transphosphatidylation of PLD. The bases used were ethanolamine, serine, ethanol and γ-hydroxybutyric acid. The phosphatidic acid, the product of PLD, was separated in TLC and measured densitometrically. The kinetic parameters were estimated for each substrate and the effects of pH, SDS, Ca2+ and other metal ions were examined. Vmax values found were 3.75, 2.36, 5.59, 1.63, 2.30 nmol/min/μg protein for phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylethanol, and phosphatidylburytic acid, respectively. These results indicate a broad specificity of cabbage PLD toward phospholipids with different head groups. Particularly phosphatidylserine was most easily hydrolyzed by PLD and its activity did not depend on Ca2+.

• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.1001-1003
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• 1994

A series of phosphodiesters of p-nitrophenyl phosphoryl derivatives were synthesized and used as a model substrate for phospholipase D (PLD). The phosphodiester substrates were synthesized from p-nitrophenyl phosphorodichloridate and corresponding alcohols with different chain lengths and polar groups. To measure the activity of PLD, either spectroscopic method for p-nitrophenol or pH-stat titration method was employed. For each substrate, effects of substrate concentration, pH, and $Ca^{2+}$ ion were examined. The kinetic parameters $V_{max}$ for the different substrates were varied depending on the chain lengths or charge of the alcohols. No calcium effect was observed in the hydrolysis of neutral and negatively charged alcohol derivatives, while positively charged choline derivative showed a strong $Ca^{2+}$ ion dependence.