• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.303-306
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• 2005

Effect of a ferromagnetic layer thickness on a narrow domain wall width is investigated. It is found that the narrow domain wall is formed in ferromagnetic/nonmagnetic/ferromagnetic multi layer structure with a loc at interlayer exchange coupling, and that the width of the narrow domain wall is affected by the ferromagnetic layer thickness. We performed micromagnetics simulations for the $Fe_1/Cr/Fe_2$ system with the local interlayer exchange coupling, with fixed thickness (20-nm) of $Fe_2$ layer and various $Fe_1$ layer thickness (1, 2, 4, and 6 nm). Consequently, we confirmed that the thinner the $Fe_1$ layer thickness, the thinner the width of the domain wall is formed, because of the surface energy nature of the interlayer exchange coupling.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.237-242
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• 2012

In this paper, we investigated effects of ITO electrode geometry and dielectric layer thickness on the discharge Characteristic of AC PDP. As the dielectric thickness is decreased ($30{\sim}12{\mu}m$), firing and sustain voltage is decreased. Luminance and discharge power increase with decreasing dielectric layer thickness because of increasing capacitance between plasma and electrodes. Reactive power decreases with dielectric thickness due to reduced capacitance between sustain electrodes. For the high Xe test panel with small ITO electrode, luminous efficacy as well as luminance increase with decreasing dielectric layer thickness. This result suggest that high power density and small plasma volume is beneficial for high efficacy discharge.

• Journal of Integrative Natural Science
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• v.3 no.4
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• pp.206-209
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• 2010

As the etching time is varied, the change of thickness of the porous silicon layers was successfully investigated. The thickness of the PSi layer as a function of anodization time for a p-type substrate that is etched at a constant current density of 50 $mA/cm^2$ in a 35% hydrofluoric acid solution shows a linear relationship between the etching time and the thickness of the PSi layer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.1
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• pp.45-49
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• 2014

We have fabricated white organic light-emitting diodes (OLEDs) using several thicknesses of electron-transport layer. The multi-emission layer structure doped with red and blue phosphorescent guest emitters was used for achieving white emission. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was used as an electron-transport layer. The thickness of BCP layer was varied to be 20, 55, and 120 nm. The current efficiency, emission and recombination characteristics of multi-layer white OLEDs were investigated. The BCP layer thickness variation results in the shift of emission spectrum due to the recombination zone shift. As the BCP layer thickness increases, the recombination zone shifts toward the electron-transport layer/emission-layer interface. The white OLED with a 55 nm thick BCP layer exhibited a maximum current efficiency of 40.9 cd/A.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04a
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• pp.27-28
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• 2008

We have studied an organic layer-thickness dependent electrical and optical properties of organic light-emitting diodes in a device structure of ITO/TPD/$Alq_3$/LiF/Al. While a hole-transport layer thickness of TPD was varied from 35 to 65nm, an emissive layer thickness of $Alq_3$ was varied from 50 to 100nm. A ratio of those two layers was kept to about 2:3. Variation of the layer thickness changes a traverse time of injected carriers across the organic layer, so that it may affect on the chance of probability of exciton formation. Current-voltage-luminance characteristics of the devices show that there are typical rectifying behaviors, and the luminance reaches about $30,000cd/m^2$. Thickness-dependent current efficiency shows that there is a gradual increase of the efficiency as the total layer thickness increases. The efficiency becomes saturated to be about 10cd/A when the total thickness is above 140nm. They show that emission was from the $Alq_3$ layer, because the peak wavelength is about 525nm. View angle-dependent emission spectra show that the emission intensity decreases as the angle increases.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.43-46
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• 1988

In this paper, a methodology for determination of the thickness of layer on a substrate using reflection acoustic microscope has been presented. It has been shown that the amplitude and the phase of reflection coefficient of the layer-substrate composite has been used for measurement of layer thickness, acoustic velosity, mass density of the layer material. The reflection acoustic microscope operating at a frequency of 15 MHz has been used for the experiment and the measured acoustic impedance value for aluminum sample has agreed with the published data, and the measured layer thickness for silver-glass composite has agreed with that measured using micrometer.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.266-269
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• 2005

The effect of exit temperature on the thickness of recrystallization layer during Al extrusion process was investigated. The recrystallization layer of an extruded Al alloy is an important feature of the product in a wide range of applications, particularly those within the automotive industry. The thicker recrystallized layer in the Al alloys can give rise to a number of problems including reduced fatigue resistance and orange peel during cold forming. But the interaction of extrusion process variables with the thickness of recrystallization layer is poorly understood, and there is limited information available regarding the role of the main hot extrusion variables. Using the 3650 US ton extrusion press, this paper describes the effect of the main process variables such as billet temperature, ram speed, and exit temperature on the thickness of recrystallization layer for the A6XXX Al alloy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.8 s.239
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• pp.956-962
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• 2005

A three-dimensional computation was conducted to make a study about effects of the inlet boundary layer thickness on the total pressure loss in a low-speed axial compressor operating at the design condition ($\phi=85\%$) and near stall condition($\phi=65\%$). Differences of the tip leakage flow and hub corner-stall induced by the inlet boundary layer thickness enable the loss distribution of total pressure along the span to be altered. At design condition, total pressure losses for two different inlet boundary layers are almost alike in the core flow region but the larger loss is generated at both hub and tip when the inlet boundary layer is thin. At the near stall condition, however, total pressure loss fer the thick inlet boundary layer is found to be greater than that for the thin inlet boundary layer on most of the span except the region near hub and casing. Total pressure loss is scrutinized through three major loss categories in a subsonic axial compressor such as profile loss, tip leakage loss and endwall loss using Denton's loss model, and effects of the inlet boundary layer thickness on the loss structure are analyzed in detail.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.401-406
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• 2018

We investigated the effect of ZnO seed layer thickness on the density of ZnO nanorod arrays. ZnO has been deposited using two distinct processes consisting of the seed layer deposition using ALD and subsequent hydrothermal ZnO growth. Due to the coexistence of the growth and dissociation during ZnO hydrothermal growth process on the seed layer, the thickness of seed layer plays a critical role in determining the nanorod growth and morphology. The optimized thickness resulted in the regular ZnO nanorod growth. Moreover, the introduction of ALD to form the seed layer facilitates the growth of the nanorods on ultrathin seed layer and enables the densification of nanorods with a narrow change in the seed layer thickness. This study demonstrates that ALD technique can produce densely packed, virtually defect-free, and highly uniform seed layers and two distinctive processes may form ZnO as the final product via the initial nucleation step consisting of the reaction between $Zn^{2+}$ ions from respective zinc precursors and $OH^-$ ions from $H_2O$.