• 분석과학
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• 제16권2호
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• pp.110-116
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• 2003

사용 후 핵연료의 화학특성 연구를 위하여 요오드의 분리와 정량에 관한 연구를 수행하였다. 사용 후 핵연료를 용해시키는 과정에서 핵연료 중에 CsI로 존재하는 요오드가 $I_2$로 산화되어 휘발되지 않도록 질산과 염산의 혼합산 (80:20 mol%)을 이용하여 비휘발성 ${IO_3}^-$­로 안정화시켰다. 2.5 M $HNO_3$ 매질에서 $NH_2OH{\cdot}HCl$을 이용하여 $I_2$로 환원시킨 후 사염화탄소로 추출하여 우라늄과 핵분열생성물로부터 분리, 회수하였다. 0.1 M $NaHSO_3$을 사용하여 요오드를 역추출하였으며 수용액층으로 회수된 요오드를 이온 크로마토그래피로 정량하였다. 방사성 물질 분석에 적합한 이온 크로마토그래피/차폐 시스템을 구성하였으며 42,000~44,000 MWd/MtU 의 연소도를 갖는 사용후핵연료를 대상으로 요오드를 분석한 결과 Origin 2 연소도 전산코드에 의한 계산결과인 $324.5{\sim}343.6{\mu}g/g$와는 -8.3~-0.5%의 편차를 나타내었다.

• Natural Product Sciences
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• 제9권1호
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• pp.13-17
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• 2003

The hepatoprotective effect of the ethanolic extract of Coccinia indica fruits in rats treated with carbon tetrachloride. In hepatotoxic rats, liver damage was studied by assessing parameters such as aspartate aminotransferase (AST), alanine aminotransferase (AlT), alkaline phosphatase (AIP) and gamma glutamyl transpeptidase (GGT) in serum, and concentrations of total proteins, total lipids, phospholipids, triglycerides and cholesterol in both serum and liver. The effect of co-administration of ethanolic extract on the above parameters was further investigated. Histopathological study of the liver in experimental animals was also undertaken. Hepatic damage as evidenced by a rise in the levels of AST, AIT, AIP and GGT in serum, and also changes observed in other biochemical parameters In serum and liver showed a tendency to attain near normalcy in animals co-administered with the extract. The normal values for AST (IU/L), AIP (IU/I), protein (g/100 ml) and total lipids (mg/100 ml) in serum (i.e.,20.24, 70.04, 5.72 and 135.54 respectively) were found to alter towards values 32.61, 127.11, 3.83 and 265.91 in hepatotoxic rats. These parameters Attained near normal values (I.e.,22.82, 79.30, 5.22 and 151.24 for AST, AIP protein and total lipids respectively) in ethanolic extract co-administered rats. Profound steatosis, ballooning degeneration and nodule formation observed in the hepatic architecture of $CCl_4$ treated rats were found to acquire near-normalcy in drug co-administered rats, thus corroborating the biochemical observations. Thus the study substantiates the hepatoprotective potential of ethanolic extract of Coccinia indica fruits.

• 전자공학회논문지A
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• 제30A권12호
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• pp.51-59
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• 1993

A 4${\times}10^{19}cm^{3}$ carbon-doped base AlGaAs/GaAs HBY was grown using carbontetracholoride(CCl$_4$) by atmospheric pressure MOCVD. Abruptness of emitter-base junction was characterized by SIMS(secondary ion mass spectorscopy) and the doping concentration of base layer was confirmed by DXRD(double crystal X-ray diffractometry). Mesa-type HBTs were fabricated using wet etching and lift-off technique. The base sheet resistance of R$_{sheet}$=550${\Omega}$/square was measured using TLM(transmission line model) method. The fabricated transistor achieved a collector-base junction breakdown voltage of BV$_{CBO}$=25V and a critical collector current density of J$_{O}$=40kA/cm$^2$ at V$_{CE}$=2V. The 50$\times$100$\mu$$^2$ emitter transistor showed a common emitter DC current gain of h$_{FE}$=30 at a collector current density of JS1CT=5kA/cm$^2$ and a base current ideality factor of ηS1EBT=1.4. The high frequency characterization of 5$\times$50$\mu$m$^2$ emitter transistor was carried out by on-wafer S-parameter measurement at 0.1~18.1GHz. Current gain cutoff frequency of f$_{T}$=27GHz and maximum oscillation frequency of f$_{max}$=16GHz were obtained from the measured Sparameter and device parameters of small-signal lumped-element equivalent network were extracted using Libra software. The fabricated HBT was proved to be useful to high speed and power spplications.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권6호
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• pp.32-37
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• 2013

The scope of this study was to develop, design, and build an ex-situ remediation system of using the heating and water sparging treatment for the highly volatile DNAPL (Dense Non-Aqueous Phase Liquid) contaminated groundwater, and to conduct pilot testing at the site contaminated with DNAPL. The TCE (Trichloroethylene) removal was at the highest rate of 94.6% with the water sparging at $70^{\circ}C$ in the lab-scale test. The pilot-scale remediation system was developed, designed, and fabricated based on the results of the lab-scale test conducted. During the pilot-scale testing, DNAPL-contaminated groundwater was detained at heat exchanger for the certain period of time for pre-heating through the heat exchanger using the thermal energy supplied from the heater. The heating system supplies thermal energy to the preheated DNAPL-contaminated groundwater directly and its highly volatile TCE, $CCl_4$ (Carbontetrachloride), Chloroform are vaporized, and its vaporized and treated water is return edback to the heat exchanger. In the pilot testing the optimum condition of the HWSRS was when the water temperature at the $40^{\circ}C$ and operated with water sparging concurrently, and its TCE removal rate was 90%. The efficiency of the optimized HWSRS has been confirmed through the long-term performance evaluation process.

• Toxicological Research
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• 제3권2호
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• pp.129-141
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• 1987

Hepatocytes isolated from rats which have been pretreated with phenobarbital (80 mg/kg for 3 days), were able to take up N-acetylcysteine from surrounding medium and were able to synthesize the reduced glutathione ($GSH^{\ast}-3$) intracellularly. The N-acetylcysteine is quickly deacetylated after the uptake and increases the pool size of cysteine, which was very low initially (5 nmol/$10^6$ cells). From this increased intracellular cysteine pool, GSH was synthesized. Freshly isolated rat hepatocytes contained a high level of GSH (30 nmol/$10^6$ cells), but upon incubation with the diethylmaleate, it was markedly decreased (10 nmol/$10^6$ cells). The hepatocytes with depleted GSH have lost viability upon incubations with acetaminophen (5mM) and paraquat (2 mM). However, when the N-acetylcysteine (1 mM) was added to this incubation condition, these chemical induced hepatocellular necrosis were prevented for longer durations. This N-acetylcysteine dependent protective effect against the hepatotoxic chemicals was lost by adding methionine sulfoximine (10 mM), an inhibitor of GSH biosynthesis. Both the carbontetrachloride (5 mM) and chioroform (5 mM) added to the incubation medium caused rapid losses of GSH and cell viability, even without the prior depletion of cellular GSH. However, again, if the 1mM N-acetylcysteine was supplemented, the rates of losses of GSH and cell viability were retarded in both cases. Even though large amounts of the added N-acetylcysteine was present in the cell, N-acetylcysteine conjugate of acetaminophen was not formed. Instead, only large amounts of GSH conjugate of the drug was produced. Thus, it is concluded that the added N-acetylcysteine is taken up and utilized for resynthesis of GSH. In turn, this resynthesized GSH contributes to the protection against cytotoxicity inducible with hepatotoxic drugs.

• 한방재활의학과학회지
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• 제23권3호
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• pp.45-53
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• 2013

Objectives The objective of present study was to investigate the effect of Ojeoksangamibang ($W\check{u}j\bar{i}s\check{a}nji\bar{a}w\grave{e}if\bar{a}ng$) extract on recovery of liver function in carbontetrachloride ($CCl_4$)-exposed rat. Methods Male rats weighing $230{\pm}7.21g$ fed experimental diet for 1 week and 28 rats were divided into 4 groups. Each of 7 rats was devided into a control group and experimental groups. We fed a control group of rats a basal diet and administered normal saline (100 mg/kg, 1 time/1 day) for 3 weeks. And we fed each experimental group of rats basal diet and administered an extract of Ojeoksangamibang extracts (100 mg/kg, 200 mg/kg, 300 mg/kg, 1 time/1 day) for 3 weeks. We measured lipid of plasma and liver, concentration of proinflammatory cytokines ($IL-1{\beta}$, IL-6 and IL-10). Statistical analysis was done by one-way analysis of variance (ANOVA) and Duncan's multiple range test with significance level at p<0.05. Results Plasma a-fetoprotein (AFP) and total protein concentration showed a tendency to decrease in Ojeoksangamibang extract-treated groups. However, plasma albumin concentration showed no significant differences in all treatment groups. Activity of plasma Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) in the Ojeoksangamibang extract-treated groups, increased addition amount of Ojeoksangamibang extracts tended to decline. Alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and ${\gamma}$-glutamyl transferase (${\gamma}$-GT) activities showed a tendency to decrease in Ojeoksangamibang extract-treated groups, increased addition amount of Ojeoksangamibang extracts tended to decline. Concentration of plasma triglyceride and total cholesterol showed a lower value than that of control group. The liver $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ concentration were decreased, and IL-10 was increased in Ojeoksangamibang extract groups, compared to control group. Plasma $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ concentration were decreased, and IL-10 was increased in Ojeoksangamibang extract groups, compared to control group. Conclusions This study suggested that Ojeoksangamibang may alleviate liver inflammatory reaction induced by liver toxicity.