• 한국전기전자재료학회논문지
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• 제20권5호
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• pp.403-409
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• 2007

In this paper, effects of the trench angle($\theta$) on the breakdown voltage according to the process parameters of p-base region and doping concentrations of n-drift region in a Trench Gate IGBT (TIGBT) device were analyzed by computer simulation. Processes parameters used by variables are diffusion temperature, implant dose of p-base region and doping concentration of n-drift region, and aspects of breakdown voltage change with change of each parameter were examined. As diffusion temperature of the p-base region increases, depth of the p-base region increases and effect of the diffusion temperature on the breakdown voltage is very low in the case of small trench angle($45\;^{\circ}$) but that is increases 134.8 % in the case of high trench angle($90\;^{\circ}$). Moreover, as implant dose of the p-base region increases, doping concentration of the p-base region increases and effect of the implant dose on the breakdown voltage is very low in the case of small trench angle($45\;^{\circ}$) but that is increases 232.1 % in the case of high trench angle($90\;^{\circ}$). These phenomenons is why electric field concentrated in the trench is distributed to the p-base region as the diffusion temperature and implant dose of the p-base increase. However, effect of the doping concentration variation in the n-drift region on the breakdown voltage varies just 9.3 % as trench angle increases from $45\;^{\circ}$ to $90\;^{\circ}$. This is why magnitude of electric field concentrated in the trench changes, but direction of that doesn't change. In this paper, respective reasons were analyzed through the electric field concentration analysis by computer simulation.

• 대한수의학회지
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• 제35권3호
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• pp.631-633
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• 1995

70 cows with abomasal torsion and 71 cows with right-side displacement of the abomasum were examined to determine whether the preoperative blood base-excess concentration could be used both as a prognostic indicator for postoperative recovery in cows with abomasal torsion and as an aid in differentiating between abomasal torsion and right-side displacement of the abomasum. The survival rate of cows with abomasal torsion decreased as the base-excess concentration decreased(P=0.08). There was a significant difference(P<0.025) among base-excess ranges between abomasal torsion and right-side displacement of the abomasum. Most cows with base-excess concentrations ${\geq}15.0mEq/L$ and ${\leq}-0.5mEq/L$ had abomasal torsion, rather than right-side displacement of the abomasum.

• 한국전기전자재료학회논문지
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• 제23권7호
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• pp.513-516
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• 2010

In this work, a study is presented of the static characteristics of 4H-SiC DMOSFETs obtained by adjustment of the p-base region. The structure of this MOSFET was designed by the use of a device simulator (ATLAS, Silvaco.). The static characteristics of SiC DMOSFETs such as the blocking voltages, threshold voltages, on-resistances, and figures of merit were obtained as a function of variations in p-base doping concentration from $1\;{\times}\;10^{17}\;cm^{-3}$ to $5\;{\times}\;10^{17}\;cm^{-3}$ and doping depth from $0.5\;{\mu}m$ to $1.0\;{\mu}m$. It was found that the doping concentration and the depth of P-base region have a close relation with the blocking and threshold voltages. For that reason, silicon carbide DMOSFET structures with highly intensified blocking voltages with good figures of merit can be achieved by adjustment of the p-base depth and doping concentration.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5745-5751
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• 2013

본 논문은 monomer에서 결합증진에 많은 역할을 하는 MMA와 TEGDMA의 농도별 표면 처리와 silane coupling agent로 표면 처리한 것이 의치상 레진과 이장재간의 결합력에 미치는 영향에 대해 알아보고자 하였다. 의치상 레진에 MMA와 TEGDMA의 농도별 표면 처리와 silane coupling agent로 표면처리 후 이장재를 주입하여 전단결합강도를 측정하였다. MMA와 TEGDMA의 농도별 표면 처리에 따른 의치상 레진과 이장재간의 전단결합강도에서는 Vertex self curing resin에서 95%, 90%, 80%, Kooliner에서는 95%, 90%에서 유의적으로 높게 나타났다(P<0.05). 또한, silane coupling agent 5%로 표면 처리한 그룹이 Vertex self curing resin과 Kooliner 모두에서 전단결합강도가 유의적으로 높게 나타났다(P<0.05). 따라서 적절한 화학적 표면 처리는 의치상 레진과 이장재간의 결합력 증가에 영향을 미치리라 사료된다.

• 한국콘텐츠학회논문지
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• 제15권2호
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• pp.344-351
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• 2015

본 논문은 치과에서 많이 사용되고 있는 silane coupling agent로 표면 처리한 의치상 레진과 자가중합 레진 간의 전단 결합력에 미치는 영향에 대해 알아보고자 하였다. 의치상 레진에 silane coupling agent 농도별 표면 처리 후 자가중합레진을 주입하여 전단결합강도를 측정하였다. Silane coupling agent(MPS)의 농도별 표면 처리에 따른 의치상 레진과 자가중합레진 간의 전단결합강도에서는 Vertex self curing resin에서 5%, 7%에서 유의적으로 높게 나타났고(P<0.05), Kooliner에서는 5%에서 유의적으로 가장 높게 나타났다(P<0.05). 따라서 의치상 레진과 자가중합레진 사이에 MPS 5%를 이용한 표면처리가 전단결합강도에 효과적으로 영향을 미치는 것이라 사료된다.

• 대한수의학회지
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• 제25권2호
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• pp.133-144
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• 1985

The changes of acid-base status in vitro of the venous blood for 24 hours in ten Korean native goat were investigated. The acid-base parameters were measured within ten minutes after collection of the blood, and every hour during the first six hours and finally after twenty four hours of storage. Blood samples were stored at two different temperatures ($0-4^{\circ}C$ and $21-24^{\circ}C$). Twelve goats were induced acute acid-base disturbances by intravenous infusion of either hydrochloric acid or sodium bicarbonate and inhalated with $CO_2$ gas mixture (20% $CO_2$, 80% $O_2$) or hyperventilation were performed by means of respirator. The results were as follows; 1. Blood samples could be stored during the first two hours in ice water ($0-4^{\circ}C$) and one hour at room temperature without significant changes in pH. The magnitudes of changes were similar to those of cow, and lower than those of men and dogs. 2. The mean values of acid-base parameters in normal goat were arterial pH, 7.40; $P_{CO_2}$, 35.4mmHg; $HCO_3{^-}$, 21.8mEq/L. 3. Both the base excess and the bicarbonate showed high correlation (r=0.99) during the metabolic disturbance and were represented as $B.E.=1.38\;HCO^-{_3}-29.7$. 4. The slope of blood buffer curve obtained from the in vivo experiment was 16.3mEq/L/pH. 5. The magnitudes of changes in hydrogen ion concentration per unit change of $P_{CO_2}$ were 0.8nM/mmHg in hypercapnia and 1.0nM/mmHg in hypocapnia. 6. The ranges of acid-base parameters in normal goat urine were pH, 6.0-8.1; $P_{CO_2}$, 42-61mmHg; $HCO_3{^-}$, 2-110mEq/L. The concentration of potassium was higher (60-200mEq/L), and that of sodium was lower (8-70mEq/L) than those of human urine.

• 약학회지
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• 제19권1호
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• pp.30-35
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• 1975

pKi values and sensitivity of acid-base indicators in the mixed solvent systems of water-alcohols and water-acetone at differential pH and in concentration media were determined by spectrophotometric method. When the concentration of the organic solvents were increased, the pKi values of sulfophthalein indicators, thymol blue and bromcresol purple, became larger whereas those of an axo indicator, methyl yellow, became smaller nad the pH values of the equivalent points of acids became smaller and the pH values of the equivalent points of acids became higher than those in the aqueous solution. potassium bicarbonate, a standard compound used in the organic solvent systems without a prerequisite procedure of expelling carbon dioxide by boiling.

• 약학회지
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• 제50권5호
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• pp.313-321
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• 2006

There are three kinds of liquid petroleum marker which is extracted by the basic or acidic, and both developer. Korean marker, Unimark 1494 DB (marker) have been spectrophotometrically analysed by the determination of absorbance at 582 nm after base extraction by Unimark 1494 DB Developer C-5 (developer). Some blue dyes which have same reactive radical of marker and can be changed deep blue color in base developer extraction (BDE), may be increased absorbance at 582 nm, but dyes or markers which can be increased the absorbance, were not unclear. In this experiment, effects of three dyes or marker such as Orimax Green 151 (the mixture of CI Solvent Yellow 16 and CI Solvent Blue 70), quinizarin and Orimax Blue 2N (CI Solvent Blue 35), and two solvent such as topasol (P-250) and lubricant (P-8) on the absorbance were studied by HITACHI Recording Spectrophotometer U-3300. It shows that all of them increased absorbance at 582 nm after BDE. Absorbance at 582 nm can be showed 0.0544 by Orimax Green 151 at the concentration of 3.96 mg/l, quinizarin at the concentration of 1.38 mg/l, and Orimax Blue 2N at the concentration of 2.73 mg/l in the artificial petroleum (normal diesel oil: topasol: lubricant=2 : 4: 4), respectively. Absorbance, 0.0544 indicates that concentration of marker is 1.64 mg/l in the reference curves, respectively. And also these results can be showed that the artificial petroleum have about 10% cheep fuel such as kerosene which have marker (16.0 mg/l). Absorbance of P-250 was 0.01361-0.22842 depending upon the purchasing date, and that of P-8 was 0.05644. pH of developer was 14.83, and so this result indicates that Unimark 1494 DB is a base extractable petroleum marker, phenylazophenol (US Patent No. 5,252,106). In the BDE, the slight color of Orimax Blue 2N, Orimax Green 151 and quinizarin in artificial petroleum changed to deep bright blue color, respectively. These result indicate that the absorbance at 582 nm by BDE may be increased not only by azo, diazo, amine and ketone (anthraquinone, coumarin) dyes or markers, but also the contaminants of P-250 and P-8 which have same as reactive radical of dyes or markers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.3-5
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• 2002

Breakdown characteristics of a punch-through diode with n+p+p-n+ structure are analyzed with two-dimensional device simulation. Effects of base doping concentration and profile on the breakdown are presented. An analytical expression of a maximum base doping level for the punch-through breakdown is derived. The diode with a linearly graded base doping shows superior leakage current and capacitance is satisfactory for applications for low-voltage circuits.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.63-63
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• 2009

In this work, we demonstrate 800V 4H-SiC power DMOSFETs with several structural alterations to observe static DC characteristics, such as a threshold voltage ($V_{TH}$) and a figure of merit ($V_B^2/R_{SP,ON}$). To optimize the static DC characteristics, we consider four design parameters; (a) the doping concentration ($N_{CSL}$) of current spreading layer (CSL) beneath the p-base region, (b) the thickness of p-base ($t_{BASE}$), (c) the doping concentration ($N_J$) and width ($W_J$) of a JFET region, (d) the doping concentration ($N_{EPI}$) and thickness ($t_{EPI}$) of epi-layer. Design parameters are optimized using 2D numerical simulations and the 4H-SiC DMOSFET structure results in high figure of merit ($V_B^2/R_{SP,ON}$>~$340MW/cm^2$) for a power MOSFET in $V_B{\sim}1200V$ range.