• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.327-331
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• 2003

This paper proposes a novel ZVZCS-PWM Boost Converter. It enables the main switch to be turned on and off with both zero voltage and zero current and the auxiliary switch to be turned on and off with ZCS, the rectify diode to be turned on and off with ZVS. Moreover, this converter is suitable for not on]y minority carrier device but also majority carrier device. The auxiliary resonant circuit of the proposed boost converter is placed out the main power path, therefore, there are no voltage/current stresses on the main switch and diode. The operation of the proposed boost converter is explained and analyzed theoretical and experimentally, from a prototype operating at 100kHz, with an input voltage rated at 50V.

• 한국결정성장학회지
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• 제8권1호
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• pp.49-54
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• 1998

수열법에 의하여 $BaTiO_3$ 미립자를 합성하였다. 출발원료로는 $TiO_2$와 $Ba(OH)_2{\cdot}8H_2O$를 사용하고 과량의 $Ba(OH)_2{\cdot}8H_2O$를 투입함으로써 증류수만을 용매로 사용하여 $150^{\circ}C$의 저온에서 BaTiO3 미립자를 합성할 수 있었다. 합성된 입자의 형태는 구형에 가까운 부정형이었으며, 입자의 크기는 합성온도 및 Ba/Ti 원자비에 따라 변화되었다.

• 대한예방한의학회지
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• 제2권1호
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• pp.45-54
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• 1998

The antilipidperoxidative and hepatopreventive effects of Houttuynia cordata extract(HCE) were investigated at the level of liver homogenates and serum of SD rats intoxicated EtOH(3g/kg for 3days). We measured MDA(malondialdehyde) in the live. homogenate, AST(1-aspartate-2-oxoglutarate aminotransferase) and ALT( 1-alanine-2-oxoglutarate aminotransferse) in the serum. The analysis of the measurement indicated that HCE reduced MDA, ALT and AST significantly and their reduction was in relation to dose dependence. In rat liver homogenate intoxicated with EtOH, HCE treatment group inhibited lipidperoxidation by 50-75%. In rat serum intoxicated EtOH, HCE inhibited AST and ALT by 40-70%.

• Journal of Pharmaceutical Investigation
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• 제9권4호
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• pp.8-12
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• 1979

A study on the effects of the root components of Angelica koreana Max. on voluntary activity in mice has confirmed that: 1. MeOH soluble Ex., MeOH insoluble Ex., oxypucedanine and isoimperatorin were antagonized against the voluntary activity in mice pretreated with a dose of C.N.B. 30mg/kg. 2. MeOH insoluble Ex. showed higher depressant effect than MeOH soluble Ex.. 3. the depressant activity of oxypucedanine was significantly more effective than that of isoimperatorin.

• 생약학회지
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• 제19권2호
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• pp.120-126
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• 1988

HPLC analysis of three Prunus species, Armeniacae Semen. Persicae Semen, and Mume Semen, showed that 24. 06 mg/g, 5. 79 mg/g and 3/ 10 mg/g of amygdalin in the MeOH extract and 3. 59 mg/g, 5. 41 mg/g and 13. 48 mg/g of benzaldehyde in the MeOH extract hydrolyzed with ${\beta}-glucosidase$ were contained respectively. The MeOH extract of Mume Semen showed strong antibacterial activities against two species of bacteria (E. coli and B. subtilis) while that of Armeniacae Semen showed mild, and that of Persicae Semen showed no effect. Against A. niger, a strong antifungal activity was observed with Armeniacae Semen and only mild activities with Persicae Semen and Mume Semen. None oh the three inhibited the growth of S. cervisiae. The above results may possibly be suggestive of the correlationships between the contents of amygdalin and benzaldehyde in the test extracts with the antimicrobial potencies.

• 생약학회지
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• 제45권1호
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• pp.35-40
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• 2014

In this study, in order to search for new functional materials from natural products, was carried out the study of antioxidant active ingredients in persimmon calyx(calyx of Diospyros kaki Thunberg). I have experimented with the effect of antioxidant activity of five different extract(MeOH, n-hexane, EtOAc, n-BuOH and $H_2O$ extract) obtained from persimmon calyx. As a result, the butanol extract, that is the main component fraction of antioxidant activity was found. Three compounds were isolated by silica gel column chromatography from the n-BuOH extract of persimmon calyx. Their structures of compound 1, 2 and 3 isolated from n-BuOH extract of persimmon calyx were identified as quercetin, (+)-catechin and gallic acid by using the TLC, $^1H$-NMR and $^{13}C$-NMR.

• 한국분말재료학회지
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• 제18권1호
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• pp.73-77
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• 2011

$Y(OH)_3$ nanowires were synthesized by a hydrothermal reaction of metallic Y with aqueous solution of LiOH. The morphology and the size of the nanowires changed with varying the volume of the LiOH solution inside the autoclave. $Y(OH)_3$ nanowires transformed to $Y_2O_3$ by a subsequent heat-treatment without morphological change. By a proper control of hydrothermal reaction parameter and heat-treatment, the yield of pure $Y_2O_3$ nanowires up to 97% was attained.

• 한국안전학회지
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• 제13권2호
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• pp.109-115
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• 1998

Tri-cresyl phosphate(TCP) was synthesized by reaction of phosphorus chloride with mixed cresol(mixture of m-cresol, p-cresol, and others) in the presence of $AlCl_3$. Some of unwanted products and unreactants colored TCP. In order to separate TCP from these, vaccume distillation was carried twice, but colorless TCP could not be producted. Separation of unwanted materials by 2% NaOH solution was introduced before first and second distillation and optimal separation conditions such as NaOH concentration, mixing volume ratio, mixing time, and rpm were investigated for new batch separation and production of colorless TCP Optimal conditions were 2% NaOH solution, 35% mixing volume ratio of 2% NaOH solution, 1.5 hours of mixing time, and 20 rpm.

• 한국대기환경학회지
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• 제34권5호
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• pp.659-667
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• 2018

$NO_x$ and $SO_2$ are mainly generated in the combustion of fossil fuels, and they cause secondary aerosol formation and acid rain in the atmosphere. Many studies have been conducted on the wet scrubbing process which can simultaneously reduce $NO_x$ and $SO_2$ at relatively low temperature. In this study, we conducted an experimental study on wet scrubbing by using NaOH solution. Especially, this study focuses on $NO_x$ and $SO_2$ removal characteristics by varying $NO_2/NO_x$ ratio and $SO_2$ concentration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.115-118
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• 2001

High-temperature superconductor films of YBa$_2$Cu$_3$$O_{7-x}$ were fabricated by electrophoretic deposition (EPD) from alcohol-based suspension. Maximum stability is observed for the suspension containing iso-alcohol as the dispersion medium. However, for the formation of a dense and adherent coating of YBCO on a silver substrate by EPD, the best results were obtained in mix PrOH and BuOH suspension. The superconducting critical current density (J$_{c}$) was 1200 A/cm$^2$ for a films deposited in 30% iso-PrOH and 70 % iso-BuOH suspension.ion.