• Environmental Engineering Research
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• 제12권4호
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• pp.148-154
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• 2007

The purpose of this research was to investigate the effects of low concentration of oxygen on reduction of perchlorate, especially low perchlorate influent concentrations in a biofilm reactor, as well as the effect of flow pattern in a biofilm reactor. Dissolved oxygen averaging 1 mg/L did not inhibit reduction of influent perchlorate from 23 to $426\;{\mu}g/L$ in the biofilm reactors when sufficient acetate was added, probably due to limitation of oxygen diffusion into the biofilm. Influent perchlorate ranging from 23 to $426\;{\mu}g/L$ was reduced to below detection level ($4\;{\mu}g/L$) in the presence of 1 mg/L dissolved oxygen (DO). Chloride was produced in a ratio of $0.37gCl^-/g{ClO_4}^-$ and $0.35gCl^-/g{ClO_4}^-$ in plug flow and recirculation biofilm reactor which is similar to stoichiometric amount ($0.36gCl^-/g{ClO_4}^-$) indicating complete perchlorate reduction at $426\;{\mu}g/L$ of ${ClO_4}^-$ feeding. At $23\;{\mu}g/L$L influent perchlorate, total biomass solids were 3.18 g and 2.81 g in the plug flow and recirculation biofilm reactors. The most probable number(MPN) analysis for perchlorate-reducing bacteria showed $10^4$ to $10^5\;cells/cm^2$ in both biofilm reactors throughout the experiments. The effluent perchlorate concentrations were not significantly different in the two different flow regimes, plug flow and recirculation biofilm reactors.

• 한국분말재료학회지
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• 제16권2호
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• pp.98-103
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• 2009

The ultrafine titanium carbonitride particles ($TiC_{0.7}N_{0.3}$) below 100nm in mean size were successfully synthesized by Mg-thermal reduction process. The nanostructured sub-stoichiometric titanium carbide ($TiC_{0.7}$) particles were produced by the magnesium reduction at 1123K of gaseous $TiC_{l4}+xC_2Cl_4$ and the heat treatments in vacuum were performed for five hours to remove residual magnesium and magnesium chloride mixed with $TiC_{0.7}$. And final $TiC_{0.7}N_{0.3}$ phase was obtained by nitrification under normal $N_2$ gas at 1373K for 2 hrs. The purity of produced $TiC_{0.7}N_{0.3}$ particles was above 99.3% and the oxygen contents below 0.2 wt%. We investigated in particular the effects of the temperatures in vacuum treatment on the particle refinement of final product.

• 상하수도학회지
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• 제13권2호
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• pp.47-54
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• 1999

SRB(Sulfate Reducing Bacteria) converts sulfate into sulfide using an organic carbon source as the electron donor. The sulfide formed precipitates the various metals present in the AMD (Acid Mine Drainage). This study is the fundamental research on heavy metal removal from AMD using SRB. Two completely mixed anaerobic reactors were operated for cultivation of SRB at the temperature of $30^{\circ}C$ and anaerobic batch reactors were used to evaluate the effects of carbon source, COD/sulfate($SO_4^=$) ratio and alkalinity on sulfate reduction rate and heavy metal removal efficiency. AMD used in this study was characterized by low pH 3.0 and 1000mg/l of sulfate and dissolved high concentration of heavy metals such as iron, cadmium, copper, zinc and lead. It was found that glucose was an organic carbon source better than acetate as the electron donor of SRB for sulfate reduction in AMD. Amount of sulfate reduction maximized at the COD(glucose)/sulfate ratio of 0.5 in the influent and then removal efficiencies of heavy metals were 97.5% of Cu, 100% of Pb, 100% of Cr, 49% of Mn, 98% of Zn, 100% Cd and 92.4% of Fe. Although sulfate reduction results in an increase in the alkalinity of the reactor, alkalinity of 1000mg/1 (as $CaCo_3$) should be should be added continuously to the anaerobic reactor in order to remove heavy metals from AMD.

• 상하수도학회지
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• 제7권1호
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• pp.20-28
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• 1993

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

• 대한약리학회지
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• 제10권1호
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• pp.61-65
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• 1974

Berberis koreana Palibin belonging to Berberidaceae family, a common herb in Korea, has been contained some quantity of Berberine analogue and other ingredients. Authors therefore paid attention to its pharmacological actions and examined the effects on sleep duration and rectal temperature in mouse with crystal (A) from Berberis koreana Palibin in Korean native plans. The experiment searching for the effect on sleep duration was performed with pretreatment of Berberis Koreana Palibin crystal (A) 30 min before the administration of 25 % ethanol, and its crystal were also administered intraperitoneally with the intention to examine the effect on rectal temperature in mouse. The results of the experiment were as follows; 1. Crystal (A) from Berberis koreana Palibin was made by extraction with ethanol and HCI. 2. Crystal (A) enhanced the hypnotic activity of alcohol in concentratins of 0.1 mg/10g or 0.15 mg/10g. 3. Rectal temperatures in mice were significantly reduced with administration of crystal (A) in concentrations of 0.1 mg/10g or 0.15 mg/10g. 4. The maximal reduction of rectal temperature and potentiation of the hypnotic activity were observed at 30 min after its administration. From the above results, it is clear that crystal (A) from Berberis koreana Palibin exerts the potentiation of hypnotic action of alcohol and reduction of rectal temperature in normal mouse. Its pharmacological effects are probably derived from the action upon the central nervous system.

• 대한한의학방제학회지
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• 제17권1호
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• pp.129-140
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• 2009

Objectives : The goal of this study was to investigate the effect of Moutan Cortex as antidepressant in forced swimming test(FST) model. Methods : The expressions of corticotropin-releasing Factor(CRF), c-Fos and tyrosine hydroxylase(TH) were measured with immunohistochemical method at paraventricular nucleus (PVN), locus coeruleus(LC) and ventral tegmental area(VTA). Results : The duration of immobility in the forced swimming test was significantly decreased in the Moutan Cortex 100 mg/kg treated group in comparison with the control group(p<0.01). CRF and c-Fos expressions at PVN were decreased in the Moutan Cortex 100mg/kg treated group in comparison with the control group. But only the expression of c-Fos was shown the significance(p<0.05). TH expressions at LC and VTA were significantly decreased in the Moutan Cortex 100mg/kg and 400mg/kg treated group in comparison with the control group(p<0.001). Conclusion : According to the results, Moutan Cortex has the antidepressant effect by showing the reduced immobility through the reduction of c-Fos expression at PVN and the reduction of TH expression at LC and VTA.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.45-50
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• 2013

This paper focuses on the fundamental issues for improving the efficiency and throughput of the AC PDP (Plasma Display Panel) manufacturing. The properties of the MgO protective layer affect the PDP efficiency. Especially, the secondary electron emission efficiency was affected on the deposition rate of MgO during the evaporation. In this study, the deposition rate of 5 $\AA$/s has given the maximum efficiency value of 0.05 It is demonstrated that the impurity gases such as $H_2O$, $CO_2$, CO or $N_2$, and $O_2$ can be remained inside the PDP panel before sealing and the amount of the impurity gases decreased rapidly as the base vacuum level increased, especially near $10^{-5}$ torr. The fundamental solution in order to overcome these problems is the vacuum in-line sealing process from the MgO evaporation to the final sealing of the panel without breaking the vacuum. We have demonstrated this fundamental process technology and shown the feasibility. The firing voltage was reduced down to 285 V at the base vacuum value of $10^{-6}$ torr, whreras it was about 328 V at the base vacuum value of $10^{-3}$ torr.

• 한방비만학회지
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• 제17권2호
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• pp.119-126
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• 2017

Objectives: This study investigated the effects of the mixed herbal extract from Cinnamomum cassia Blume, Atractylodes macrocephala Koidzumi, Pueraria lobata Benth, and Aconitum carmichaeli Debx (CAPA) on obesity and glucose tolerance in obese mice. Methods: Animals were divided in 6 groups, normal diet, high fat diet (HFD), HFD with CAPA 100 mg/kg (CAPA 100), CAPA 300 mg/kg (CAPA 300), and metformin 200 mg/kg or lorcaserin 10 mg/kg as positive controls, and treated for 16 weeks. Body weight, food intake, fasting blood glucose, and body temperature were checked every week and then organs, blood serums were collected after treatment. The oral glucose tolerance test was also carried out after treatment. Results: Compared to HFD, CAPA extract treated mice showed significant decreases in body weight, adipose tissue weight, lipid accumulations in liver and serum lipid levels without a reduction of food intake. And fasting glucose and glucose tolerance were all improved in the CAPA treated mice. Conclusions: Our results suggest that CAPA extract can prevent diet induced obesity and glucose intolerance without a reduction of energy intake in obese mice.

• 대한금속재료학회지
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• 제50권10호
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• pp.745-751
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• 2012

The Kroll process for magnesium reduction of titanium tetrachloride is used for mass production of titanium sponge. The present study was conducted in a lab scale reactor to develop a better understanding of the mechanism of titanium sponge formation in the Kroll reactor with respect to reaction degrees and the feeding rate of $TiCl_4$. The $MgCl_2$ produced during the initial stage of the reaction was not sunk into the molten magnesium, but covered the surface of the molten magnesium. As a result, subsequently fed $TiCl_4$ reacted with Mg exposed on the edge of molten $MgCl_2$ in the crucible. Therefore, titanium sponge grew toward the center of the crucible from the edge. The temperature of the molten magnesium increased remarkably with the increasing feeding rate of $TiCl_4$. Consequently, fed $TiCl_4$ reacted at the upper side of the crucible with evaporated Mg, and produced titanium on the upper surface of the crucible wall, which increased considerably with the feeding rate of $TiCl_4$.

• 자원리싸이클링
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• 제12권2호
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• pp.21-27
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• 2003

LD제강슬래그에 함유된 바나디움 회수를 위한 기초실험 결과로써 용융환원시 염기도 최적 염기도 및 환원효율의 증가를 위하여 $SiO_2$, MgO, $Al_2$$O_3$을 첨가하였다. 이에 따라 염기도 1, 2에서 $Al_2$$O_3$의 첨가에 따라 바나디움의 환원율이 증가함이 확인되었다.