• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.58-61
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• 2001

Metal-insulator-semiconductor (MIS) C-V properties with high dielectric AIN thin films showed no hysteresis and good interface properties. The dielectric constant of the AIN film calculated from the capacitance at the accumulation region in the capacitance-voltage(C-V) characteristics was about 8. The C-V characteristics of MFIS capacitor showed a hysteresis loop due to the ferroelectric nature of the LiNbO$_3$ thin films. Typical dielectric constant value of LiNbO$_3$ film of MFIS device was about 23. The memory window width was about 1.2V at the gate voltage of $\pm$5 V ranges. Typical gate leakage current density of the MFIS structure was the order of 10$^{-9}$ A/cm$^2$ at the range of within $\pm$500 kV/cm. The ferroelectric capacitors showed no polarization degradation up to about 10$^{11}$ switching cycles when subjected to symmetric bipolar voltage pulse(peak-to-peak 8V, 50% duty cycle) in the 500kHz.

• 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.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.2
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• pp.123-131
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• 1991

In order to study the growth and maturation of ovarian follicle, the localization and activity of alkaline phosphatase(ALPase) and adenosine triphosphatase(ATPase) of the granulosa cells and theca layer were examined according to the follicle size, the follicle state and the ovarian cyclic phase in pig. Theca interna of the small follicles was more heavyly localized with reaction product by the activites of ALPase and ATPase than that of the large follicles. It is assumed that, as the follicles proceed to growth and maturation, antrum formation is the result of the follicular fluid accumulation by means of active transport by the activities of ALPase and ATPase in theca interna. The activities of ALPase and ATPase in atretic follicles were higher than those of normal follicles. These results imply that the mechanisms of follicle maturation and atresia are different according to the phase of ovarian cycle.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.5
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• pp.38-45
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• 1989

We have studied the electrical characteristics of the hydrogenated amorphous silicon (a-Si:H) ambiploar thin film transistors (TET'S)using 100ppm boron-doped a-Si:H as an active layer. The enhancement of drain current due to the double injection behavior has been observed in the p-channel operation of the TFT. The drain current decreases with time in streched exponential form when the gate voltage is positive. The result indicates that the dangling bonds created by electron accumulation show identical time dependence as the diffusion of hydrogen in the film. We observed the experimental evidence that the doping efficiency changes either when the gate bias is applied or when the light is illuminated on boron-doped a-Si:H.

• Toxicological Research
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• v.15 no.1
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• pp.1-8
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• 1999

This study was performed to investigate the antitoxic effect of Oenanthe javanica extracts on orally administered mercury compound. Adult male ICR mice were exposed to methylmercuric chloride (CH3HgCl)through drinking water. The control, mercury treated and Oenanthe javanica treated groups not showed significant differences in mean body and organ weights of mice. The distribution of mercury in the cerebellum, kidney, liver and spleen of the mouse were examined according to a histochemical mathod. Grains of mercury traces were located in the purkinje cell and granular layers of the cerebellum and cortex of kidney respectively. Lesser staining of the grains was seen in the collecting tubules of medulla. in the liver, mercury accumulations were present primarily in the hepatocytes around portal area containing interlobular bile duct, artery and portal vein. Also grains of mercury traces were accumulated in the white pulp of the spleen. In the group of Oenanthe javanica extracts, staining intensity of mercury was decreased in the Purkinje cell layer of cerebellum and in the portal area of liver respectively. Staining patterns in kidney and spleen of extracts group were similar to that of only mercury treated group.

• Corrosion Science and Technology
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• v.2 no.1
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• pp.7-11
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• 2003

Photoelectrochemical response and electrochemical impedance behavior was investigated for passive film formed on sputter-deposited Cr alloy in $0.1kmol{\cdot}m^{-3}$. Photoelectrochemical action spectrum could be separated into two components, which were considered to be derived from $Cr_2O_3$ ($E_g\sim3.6eV$) and $ Cr(OH)_3 $ ($E_g\sim2.5eV$). The band gap energy, $E_g$, of each component was almost constant for various applied potentials. polarization periods and alloying additives. The photoelectrochemical response showed negative photo current for most potentials in the passive region. Therefore, the photo current apparently exhibited p-typesemiconductor behavior. On the other hand, Mort-Schottky plot of the capacitance showed positive slope, which means that passive film formed on Cr alloy has n-type semiconductor property. These apparently conflicting results are rationally explained assuming that the passive film on Cr alloy formed in the acid solution has n-type semiconductor property with a fairly deep donor level in the band gap and forms an accumulation layer in the most of potential region in the passive state.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.91-95
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• 2003

The nephrotic syndrome is characterized by generalized edema, hypoproteinemia(<2 g/dL), proteinuria(>40 $mg/m^2/hr$), and hypercholesterolemia(>200 mg/dL). It is reported that hypoalbuminemia, which is one of the four diagnostic criteria of the nephrotic syndrome, is associated with gallbladder wall thickening. An explanation for the thickened wall in hypoalbuminemic states is the accumulation of fluid in the subserosal layer of the gallbladder wall which contains the most areolar tissue. This report describes a patient who was initially diagnosed with the nephrotic syndrome at the age of 4 and subsequently developed acute acalculous cholecystitis at the age of 5.8 with an albumin level of 1.3 g/dL. The patient responded to fluid therapy, nasogastric suction, and broad spectrum antibiotics.

• Nuclear Engineering and Technology
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• v.47 no.5
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• pp.567-578
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• 2015

In a nuclear reactor containment, wall condensation forms with noncondensable gases and their accumulation near the condensate film leads to a significant reduction in heat transfer. In the framework of nuclear reactor safety, the film condensation in the presence of noncondensable gases is of high relevance with regards to safety concerns as it is closely associated with peak pressure predictions for containment integrity and the performance of components installed for containment cooling in accident conditions. In the present study, CUPID code, which has been developed by KAERI for the analysis of transient two-phase flows in nuclear reactor components, is improved for simulating film condensation in the presence of noncondensable gases. In order to evaluate the condensate heat transfer accurately in a large system using the two-fluid model, a mass diffusion model, a liquid film model, and a wall film condensation model were implemented into CUPID. For the condensation simulation, a wall function approach with a heat/mass transfer analogy was applied in order to save computational time without considerable refinement for the boundary layer. This paper presents the implemented wall film condensation model, and then introduces the simulation result using the improved CUPID for a conceptual condensation problem in a large system.

• Corrosion Science and Technology
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• v.16 no.6
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• pp.298-304
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• 2017

Coil spring steels from the automobile suspension part after field exposure for 10 years and those after anti-corrosion validation test in proving ground of 5,000 ~ 10,000 km were examined for corrosion damages. Partial loss of paint, accumulation of corrosion product, and cracking of paint and superficial material were observed. The surface and subsurface region of spring steels had compressive residual stress and high hardness by shot peening. The surface hardness values of the specimens were 620 ~ 670 Hv. They were 60 ~ 80 Hv higher than those of the samples taken from the middle part of the spring. The maximum compressive stress was -916 ~ -1208 MPa measured at depth of about $100{\mu}m$. Electrochemical impedance spectroscopy showed that the resistances of charge transfer and the paint layer of the spring steels ranged from several tens to millions ${\Omega}{\cdot}cm^2$. The resistance of the field samples was much higher than that of the proving ground samples used in this study, implying that the proving ground test condition would be more corrosive than the field environment.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.298-302
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• 2009

A poodle with clinical signs of colorectal disease was diagnosed as pneumatosis coli. In this dog, hypoadrenocorticism and immune-mediated hemolytic anemia concurred. Pneumatosis coli is one of the emphysematous gastrointestinal diseases. The etiology is unknown but mechanical, pulmonary and bacterial theories have been proposed. In pneumatosis coli, gas accumulates within submucosal or subserosal layer of colon or rectum, so intramural radiolucent gas is observed on abdominal radiographs. In this dog, intramural gas accumulation occurred in cecum. Definitive diagnosis was based on radiographic findings and an underlying cause was not elicited. Pneumatosis coli should be included into differential diagnosis for nonspecific colorectal signs.