• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.275-275
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• 2008

This paper describe the fabrication of a Pd/polycrystalline 3C-SiC schottky diode and its characteristics, in which the polycrystalline 3C-SiC layer and Pd Schottky contact were deposited by using APCVD and sputter, respectively. Crystalline quality, uniformity, and preferred orientations of the Pd thin film were evaluated by SEM and XRD, respectively. Pd/poly 3C-SiC Schottky diodes were fabricated and characterized by I-V and C-V measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$ and 0.58 eV, respectively. These devices were operated until about $400^{\circ}C$. Therefore, from these results, Pd/poly 3C-SiC Schottky devices have very high potential for high temperature chemical sensor applications.

• Journal of Ecology and Environment
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• v.32 no.1
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• pp.41-45
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• 2009

For last 150 years, blackbirds have moved from their ancestral habitat, the woodland edge, to man-made habitats such as farmland, parks and gardens. These alternative habitats have become one of main blackbird habitats. I compared density of nests and blackbirds in parks, woodland and campus of University of East Anglia to investigate habitat preference. Blackbirds preferred the area covered by $10\sim50%$ of tree or bush patches for their foraging and nesting sites. Blackbirds were more frequently found near buildings rather than far from buildings. Nest characteristics did not affect predation rate and nest preference. This study suggests that man-made habitats may be important for avoiding predation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.497-501
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• 2009

Effect of angle of supply air on cooling and heating performances of office space is studied by numerical simulation. For a constant air volume(CAV) air-conditioning system, air is supplied vertically($90^{\circ}$) and horizontally($10^{\circ}$). Due to buoyancy, the supply angle affects the performance of cooling and heating. In cooling, since the cold supply air tends to move downward due to its high density, horizontal supply angle is better for uniform temperature distribution. In heating, however, vertical supply angle is preferred for better mean and uniform temperature distribution.

• Nuclear Engineering and Technology
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• v.44 no.1
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• pp.89-102
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• 2012

The buffer and backfill are important components of the engineered barrier system in a high-level waste repository, which should be constructed in a hard rock formation at a depth of several hundred meters below the ground surface. The primary function of the buffer and backfill is to seal the underground excavation as a preferred flow path for radionuclide migration from the deposited high-level waste. This study investigates the hydraulic conductivity and swelling pressure of Kyungju Ca-bentonite, which is the candidate material for the buffer and backfill in the Korean reference high-level waste disposal system. The factors that influence the hydraulic conductivity and swelling pressure of the buffer and backfill are analyzed. The factors considered are the dry density, the temperature, the sand content, the salinity and the organic carbon content. The possibility of deterioration in the sealing performance of the buffer and backfill is also assessed.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.38.1-38.1
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• 2018

With upcoming high-quality data from surveys such as eBOSS or DESI, improving the theoretical modeling and gaining a deeper understanding of the effects of neutrinos and dark radiation on structure formation at small scales are necessary, to obtain robust constraints free from systematic biases. Using a novel suite of hydrodynamical simulations that incorporate dark matter, baryons, massive neutrinos, and dark radiation, we present a detailed study of their impact on Lyman-Alpha forest observables. In particular, we accurately measure the tomographic evolution of the shape and amplitude of the small-scale matter and flux power spectra and search for unique signatures along with preferred scales where a neutrino mass detection may be feasible. We then investigate the thermal state of the intergalactic medium (IGM) through the temperature-density relation. Our results indicate that the IGM at z ~ 3 provides the best sensitivity to active and sterile neutrinos.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.356.2-356.2
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• 2014

Spin Transfer Torque (STT) is of great interest in data writing scheme for the Magneto-resistive Random Access Memory (MRAM) using Magnetic Tunnel Junction (MTJ). Scalability for high density memory requires ferromagnetic electrodes having the perpendicular magnetic easy axis. We investigated CoZr as the ferromagnetic electrode. It is observed that interfacial magnetic anisotropy is preferred perpendicular to the plane with thickness dependence on the interfaces with Pt layer. The anisotropy energy (Ku) with thickness dependence shows a change of magnetic-easy-axis direction from perpendicular to in-plane around 1.2 nm of CoZr. The interfacial anisotropy (Ki) as the directly related parameters to switching and thermal stability, are estimated as $1.64erg/cm^2$ from CoZr/Pt multilayered system.

• Journal of Powder Materials
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• v.6 no.2
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• pp.152-162
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• 1999

The present study is concerned with the effect of PM process variables on the microstructure by using atomized superalloy powders. It is suggested that the inhomogeneity of composition is strongly dependent on the process variables. The contents of segregation elements of plasma rotating electrode process (PREP) powders are larger than those of Ar atomization (AA) powders. As HIP treatment temperature in-increases, the secondary phases on the prior particle boundaries (PPB) have continuous,uniform distribution and high density, but the amount of PPB decreases suddenly at 1150$^{\circ}$C. Segregated phases on the PPB are identified to be MC type carbide. Brittle MC type carbides on the PPB provide fracture initiation sites and preferred fracture path, thereby leading to intergranular type brittle fracture.

• Culinary science and hospitality research
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• v.23 no.4
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• pp.74-80
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• 2017

This study was to investigate the physiological activity of cookies with Sanguisorba officinalis L. powder. Our results showed that the pH of the cookies ranged from 6.34 to 6.29, and the density ranged from 4.12 to 4.40. Increasing the amount of Sanguisorba officinalis L. powder in the cookies decreased the spread factor of the cookies and tended to decrease lightness (L) in the Hunter color value with yellowness (b) and redness (a) increased. For the textural characteristics, the addition of Sanguisorba officinalis L. powder increased hardness. The sensory evaluation showed that the cookies with Sanguisorba officinalis L. powder were preferred more than those without in color, odor, texture, taste and overall preference. Based on the results above, the cookies that contained 3% of Sanguisorba officinalis L. powder presented the best quality.

• Transactions on Electrical and Electronic Materials
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• v.3 no.4
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• pp.5-9
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• 2002

Chemical mechanical polishing (CMP) has become the preferred planarization method for multilevel interconnect technology due to its ability to achieve a high degree of feature level planarity. Especially, to achieve the higher density and greater performance, shallow trench isolation (STI)-CMP process has been attracted attention for multilevel interconnection as an essential isolation technology. Also, it was possible to apply the direct STI-CMP process without reverse moat etch step using high selectivity slurry (HSS). In this work, we determined the process margin with optimized process conditions to apply HSS STI-CMP process. Then, we evaluated the reliability and reproducibility of STI-CMP process through the optimal process conditions. The wafer-to-wafer thickness variation and day-by-day reproducibility of STI-CMP process after repeatable tests were investigated. Our experimental results show, quite acceptable and reproducible CMP results with a wafer-to-wafer thickness variation within 400$\AA$.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3614-3617
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• 2011

A density functional theory method with the local basis set was employed to perform slab calculations to study thiolate-induced surface reconstruction structures of butylthiolates (ButS) with c($4{\times}2$) superlattice of the Au(111) surface. The slab calculations indicate that the most stable adsorption structure is the ButS-Au (adatom)-SBut complex form, which is in good agreement with the reported experiments and theoretical results for thiolates with shorter alkyl chains. The cis form of ButS-Au (adatom)-SBut motifs is preferred by 0.11 eV with respect to the trans form, and by 0.15 eV over the mixed cis-trans configurations due to the steric hindrance between adjacent butyl groups. It appears that the motif of Au adatom on the Au(111) surface is favored even for butylthiolate.