• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.2
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• pp.101-107
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• 2009

Investigation of resaturation and thermal-hydro-mechanical behavior for the buffer of a repository requires measuring the water content of compacted bentonite. This study investigated the relative humidity of compacted bentonites using a humidity sensor (Vaisala HMT 334) applicable under high temperature and pressure, and then conducted a multi-regression analysis based on the measured results to determine relationships among the water content, relative humidity, and temperature. The relationships for the compacted bentonites with the dry densities of 1,500 $kg/m^3$ and 1,600 $kg/m^3$ were expressed as ${\omega}=0.196RH-0.029T+1.391({r^2=0.96)}$ and ${\omega}=0.199RH-0.029T+2.596({r^2=0.98)}$, respectively. These were then used to interpret the resaturation of bentonite blocks in the KENTEX test.

• Journal of Sensor Science and Technology
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• v.3 no.1
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• pp.83-87
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• 1994

The polycrystalline $CuInS_{2}$ thin films were prepared by annealing in vacuum and extra S supply of S/In/Cu stacked layers, which were deposited by sequential electron beam evaporation(EBE). n-type $CuInS_{2}$ was fabricated in vacuum with chalcopyrite structure and its minimum resistivity was $142{\Omega}Cm$. Also, p-type $CuInS_{2}$ was made in extra S supply with chalcopyrite structure and its minimum resistivity was $137{\Omega}Cm$.

• Membrane Journal
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• v.5 no.3
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• pp.109-118
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• 1995

In this study, cell resistivity and membrane resistivity were measured in Fe-Cr redox-fiow battery system using commercial ion-exchange membranes. Cell resistivity and membrane resistivity at charging periods are higher than at discharging periods. And at the same membrane the resistivity were increased with increasing SOC. The resistivity of hydrocarbon type Seiemion CMV membrane was smaller than perfluoro type Nafion 117 and Nafion 551. The cell resistivity and membrne resistivity of CMV membrane at 0 % SOC was $12.864\Omega \textrm{cm}^2$ and $8.751\Omega \textrm{cm}^2$, respectively.

• Solar Energy
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• v.17 no.3
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• pp.51-57
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• 1997

Cu-doped ZnTe thin films have been grown by hot-wall evaporation. The electrical conductivity of the intrinsic ZnTe film was of p-type and as low as $10^{-6}({\Omega}{\cdot}cm)^{-1}$. As the doped Cu concentration was increased, the electrical conductivity was increased. up to $10^2({\Omega}{\cdot}cm)^{-1}$, but the mobility was decreased a little. The heavily doped sample shows the metal-like electrical resistivity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.1127-1134
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• 2000

$RuO_2$ thin films are prepared by RP magnetron reactive sputtering and their characteristics of crystalliBation,microstructure, surface roughness and resistivity are studied with various O2/(Ar+O2)ratios and substrate temperatures. As O2/(Ar+O2) ratio decreases and substrate temperature increases, the preferred growing plane of$RuO_2$ thin films are changed from (110) to (101) plane. With increase of the 021(Ar+O2) ratio from 2075 to 50%, the surface roughness and the resistivity of $RuO_2$ thin films increase from 2.38nm to 7.81nm, and from $103.6 \mu\Omega-cm\; to \; 227 \mu\Omega-cm$, respectively, but the deposition rate decreases from 47nm/min to 17nm/min. On the other hand, as the substrate temperature increases from room temperature to$500^{\circ}C$, resistivity decreases from $210.5 \mu\Omega-cm\; to \; 93.7\mu\Omega-cm$. $RuO_2$ thin film deposited at $300^{\circ}C$ shows a excellent surface roughness of 2.38 m. As the annealing temperature increases in the range between $400^{\circ}C$ and $650^{\circ}C$, the resistivity decreases because of the improvement of crystallinity. We find that RuO$_2$ thin film deposited at 20% of 02/(Ar+O2) ratio and $300^{\circ}C$ of substrate temperature shows excellent combination of surface smoothness and low resistivity so that it is well qualified for bottom electrode for ferroelectric thin films.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.324-329
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• 2018

This study examined the effects of the contact position and structure of the test probe on its signal transmission characteristics. The contact position in the operating of the test probe was considered and then divided into the plunger inner contact and barrel inlet contact. The high frequency performance of the test probes was investigated for both contact positions. The signal transmission characteristics of the test probes with the structures of double, single, and out-spring was also analyzed. The insertion and return losses were calculated using the HFSS and the characteristic impedance of the test probes was analyzed using a Q3D simulation. The insertion loss of the barrel inlet contact was smaller than that of the plunger inner contact. The contact position of the test probe may result in a change in the high frequency performance. The out-spring probe has better frequency characteristics at -1 dB insertion loss and -10 dB return loss. The double probe and single probe have the same characteristic impedance with $30.8{\Omega}$. On the other hand, the out-spring probe has an impedance of $47.1{\Omega}$. The out-spring probe is closer to $50{\Omega}$ than the other probes and then shows higher signal transmission characteristics. The out-spring probe has superior high-frequency characteristics and is expected to be suitable for high-speed applications.

• Journal of Korea Water Resources Association
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• v.50 no.2
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• pp.89-97
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• 2017

Turbulent flow structure in the high amplitude meandering channel is complex due to secondary recirculation with helicoidal motions and shear layers formed by flow separation from the curved sidewall. In this work, the secondary flow and the superelevation of the water surface produced in the high-amplitude Kinoshita channel are reproduced by the unsteady Reynolds-averaged Navier-Stokes (RANS) computations using the VOF technique for resolving the variation of water surface elevation and three statistical turbulence models ($k-{\varepsilon}$, RNG $k-{\varepsilon}$, $k-{\omega}$ SST). The numerical results computed by a second-order accurate finite volume method are compared with an existing experimental measurement. Among applied turbulence models, $k-{\omega}$ SST model relatively well predicts overall distribution of the secondary recirculation in the Kinoshita channel, while all three models yield similar prediction of water superelevation transverse slope. The secondary recirculation driven by the radial acceleration in the upstream bend affects the flow structure in the downstream bend, which yields a pair of counter-rotating vortices at the bend apex. This complex flow pattern is reasonably well reproduced by the $k-{\omega}$ SST model. Both $k-{\varepsilon}$ based models fail to predict the clockwise-rotating vortex between a pair of counter-rotating vortices which was observed in the experiment. Regardless of applied turbulence models, the present computations using the VOF method appear to well reproduce the superelevation of water surface through the meandering channel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.147-155
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• 1987

In order to examine the effect of dietary fish oil on lipid peroxide formation and antiperoxidative efficiency in liver and brain, a group of male and female rats weighing about 70 grams were fed for three months, diet containing mackerel oil(MO) at the level of 10% (w/w). Results were compared, according to sex and source of dietary fat, i.e., in addition to MO, perilla oil(PO), soybean oil(SO), rapeseed oil(RO) or beef tallow(BT). Liver lipid peroxide level was significantly higher and levels of ${\alpha}-tocopherol$ and reduced glutathione(GSH) were lower in MO group than in other groups. This phenomenon was less clear in male than in female. Liver GSH level was lower in male, compared to female, but oxidized glutathione (GSSG) level did not vary, depending on either sex or dietary fat source. Brain lipid peroxide and ${\alpha}-tocopherol$ levels were not different among five experimental groups. Activities of liver and brain glutathione peroxidase and superoxide dismutase were not changed by dietary fat source, but glutathione peroxidase activity was higher in female than in male. The present study shows (a) that there is sex-related difference in antiperoxidatiye activity and (b) that fish oil containing $C_{20-22}({\omega}3)$ fatty acids, increases body lipid peroxide level and consumes more of cellular antioxidant, although it has lower total PUFA content than perilla or soybean oils.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.325-331
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• 2018

This paper deals with the dynamical analysis of a vessel that leads to capsize in regular beam seas. The complete investigation of nonlinear behaviors includes sub-harmonic motion, bifurcation, and chaos under variations of control parameters. The vessel rolling motions can exhibit various undesirable nonlinear phenomena. We have employed a linear-plus-cubic type damping term (LPCD) in a nonlinear rolling equation. Using the fourth order Runge-Kutta algorithm with the phase portraits, various dynamical behaviors (limit cycles, bifurcations, and chaos) are presented in beam seas. On increasing the value of control parameter ${\Omega}$, chaotic behavior interspersed with intermittent periodic windows are clearly observed in the numerical simulations. The chaotic region is widely spread according to system parameter ${\Omega}$ in the range of 0.1 to 0.9. When the value of the control parameter is increased beyond the chaotic region, periodic solutions are dominant in the range of frequency ratio ${\Omega}=1.01{\sim}1.6$. In addition, one more important feature is that different types of stable harmonic motions such as periodicity of 2T, 3T, 4T and 5T exist in the range of ${\Omega}=0.34{\sim}0.83$.

• Journal of computational fluids engineering
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• v.13 no.1
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• pp.35-40
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• 2008

Generally flight vehicles have many cavities such as wheel wells, bomb bays and windows on their external surfaces and the flow around these cavities makes separation, vortex, shock and expansion waves, reattachment and other complex flow phenomenon. The flow around the cavity makes abnormal and three-dimensional noise and vibration even thought the aspect ratio (L/D) is small. The cavity giving large effects to the flow might make large noise, cause structural damage or breakage, harm the aerodynamic performance and stability, or damage the sensitive devices. In this study, numerical analysis was performed for cavity flows by the unsteady compressible three dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with Wilcox's $\kappa-\omega$ turbulence model. The MPI(Message Passing Interface) parallelized code was used for calculations by PC-cluster. The cavity has the aspect ratios of 2.5, 3.5 and 4.5 with the W/D ratio of 2 for three-dimensional cavities. The Sound Pressure Level (SPL) analysis was done with FFT to check the dominant frequency of the cavity flow. The dominant frequencies were analyzed and compared with the results of Rossiter's formula and Ahuja& Mendoza's experimental datum.