• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.5
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• pp.211-215
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• 2001

SBT thin films were etched at different content of $Cl_2$ in $Cl_2$/Ar or $Cl_2/N_2$(80%). As $Cl_2$ gas increased in $Cl_2$/Ar or $Cl_2/N_2$ gas plasma. the etch rate decreased. The result indicates that physical puttering of charged particles is dominant to chemical reaction in etching SBT thin films. To evaluate the etching mechanism of SBT thin films, x-ray photoelectron to chemical reaction in etching SBT thin films. To evaluate the etching mechanism of SBT thin films, x-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and atomic force microscopy (AFM) were carried out. From the result of AFM, the rms values of etched samples in Ar only or $Cl_2$ only plasma were higher than that of as-deposited, $Cl_2$/Ar and $Cl_2/N_2$ plasma. This can be illustrated by a decrease of Bi content of nonvolatile etching products (Sr-Cl and Ta-Cl), which are revealed by XPS and SIMS.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.11-14
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• 2003

[ $HfO_2$ ] thin films were deposited at $300^{\circ}C$ on p-type Si (100) substrates using $HfO_2(HfO_xN_y)$ as the precursor by plasma-enhanced chemical vapor deposition and were annealed at $300^{\circ}C$ in nitrogen plasma ambient. Compared with $HfO_2$, nitrogen plasma annealed $HfO_2$ show good chemical stability, higher crystallization temperature, lower leakage current and thermal stability. Leakage current density of nitrogen plasma annealed $HfO_2$ is approximately one order of magnitude lower than that of $HfO_2$ for the same EOT. The improvement in electrical characteristics of nitrogen plasma annealed $HfO_2$ can be explained by the better thermal stability due to nitrogen incorporation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.260-265
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• 1991

The effective method to detect the mutagenicity of N-nitrosodimethylamineI (NDMA) by using Salmonella/microsome assay was studied. The Effect of vitamin C on the mutagenicity of the formed NDMA and during the formation of NDMA from nitrite and secondary amine was also investigated. Aroclor 1254-induced hamster S9 mix was more effective in activation NDMA than rat S9 mix induced by Aroclor 1254 or phenobarbital. Dimethyl sulfoxide and ethanol suppressed the mutagenic effect of NDMA, however, phosphate butter (pH 7.4), distilled water, 95% methanol and Tween 80 + water (1 : 4) were the appropriate dissolving system in the mutagenicity test of NDMA. Vitamin C did not show any inhibitory effect on the mutagenicity of the formed NDMA. However, the revertants of Salmonella typhinutrium TA 100 were significntly reduced (p<0.05) when vitamin C was added to the reaction mixture of nitrite and dimethylamine during the formation of NDMA. The amount of the formed NDMA was analyzed using HPLC and the level was decreased by about 95%. Thus it was concluded that vitamin C inhibited greatly the formation of NDMA from nitrite and dimethylamine.

• Korean Journal of Materials Research
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• v.14 no.6
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• pp.402-406
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• 2004

$WSi_2$, $TiSi_2$, $CoSi_2$, and $TaSi_2$ are general silicides used today in semiconductor devices. $WSi_2$ thin films have been proposed, studied and used recently in CMOS technology extensively to reduce sheet resistance of polysilicon and $n^{+}$ region. However, there are several serious problems encountered because $WSi_2$ is oxidized and forms a native oxide layer at the interface between $WSi_2$ and $Si_3$$N_4$. In this study, we have introduced 20 $slm-N_2$ gas from top to bottom of the furnace in order to control native oxide films between $WSi_2$ and $Si_3$$N_4$ film. In resulting SEM photographs, we have observed that the native oxide films at the surface of $WSi_2$ film are removed using the long injector system.

• Journal of the Korean Electrochemical Society
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• v.6 no.2
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• pp.93-97
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• 2003

The electrode for a supercapacitor was prepared using an amorphous ruthenium oxide, which was synthesized from ruthenium trichloride hydrate$(RuO_2{\cdot}nH_2O)$. A supercapacitor was assembled with an electrode of ruthenium oxide material on a current collector of tantalum, and an electrolyte of 4.8 M sulfuric acid. The result of the AC impedance analyses on $Ta/H_2SO_4(4.8 M)/Pt$ cell showed that tantalum was stable at the potential range of $0.0\~1.1V(vs. SCE)$. Therefore, Ta film could be used the supercapacitor as a current collector. The irreversible hydrolysis in the supercapacitor occurred over ca. 1.0V(vs.SCE) when the supercapacitor was protonated to 0.5V(vs. SCE). The supercapacitor protonated to 0.5V(vs.SCE) showed good electrochemical properties when it was tested at the potential range of 1.0V in the charge-discharge test. The potential range of the electrodes including the positive and the negative electrode was varied between -0.004 and 0.995V(vs. SCE). The potential ranges of the positive and the negative electrode were $-0.004\~0.515V(vs.\;SCE)\;and\; 0.515\~0.995V(vs.\;SCE)$, respectively.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.333-338
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• 1998

On the mutagenicity induced by 2-aminofluorene (2-AF) with S9 mix and N-Methyl-N＇-Nitro-N-Nitrosoguanidine (MNNG) without S9 mix, the antimutagenic effects of dietary fiber (total dietary fiber, u-cellulose and pectin) from Yam were examined by the Ames assay using Salmonella typhimurium TA98 and TA100. Total dietary fiber, $\alpha$-cellulose ind pectin from natural and cultural Yam didn＇t have mutagenicity. Most of sample dietary fiber showed the antimutagenicity. Total dietary fiber from cultural Yam was more effective than that from natural Yam on mutagenicity induced by 2-AF and MNNG. $\alpha$-cellulose from cultural Yam was more effective than that from natural Yam on mutagenicity caused by 2-AF and MNNG. Pectin from natural and cultural Yam had antimutagenic effect on mutagenicity induced by MNNG. In this study, antimutagenicity on MNNG was more effective than that on 2-AF. Antimutagenic effect of Samples had influence on incubation time. $\alpha$-cellulose and pectin from natural and cultural Yam showed stronger antimutagenic effect than standard $\alpha$-cellulose and standard pectin, respectively, on mutagenicity induced by 2-AF and MNNG.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.6
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• pp.691-695
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• 2008

The study was carried out to evaluate the antimutagenic effects in methanol extracts of Korean soybean paste (doenjang) added with various kinds of water (germanium water, painted maple sap) or salt (sun-dried salt, roasted salt, one time bamboo roasted salt, nine times bamboo roasted salt). Methanol extracts of germanium water doenjang (Ge-D) and painted maple sap (Acer mono Max) doenjang (PM-D) exhibited significant inhibitory activity ($56{\sim}62%$) against aflatoxin $B_1$ ($AFB_1$) by adding of 1 mg/plate in Ames test. Also, methanol extracts of Ge-D and PM-D showed stronger antimutagenic activity toward N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in SOS chromotest than traditional doenjang (TD). Methanol extracts of doenjang made with four kinds of salt revealed antimutagenic activity toward MNNG; especially, doenjang extracts using one-time bamboo roasted salt (B1-D) showed 94% inhibition at the concentration of 5 mg/plate. Methanol extracts of B1-D also had the strongest inhibitory effect against MNNG of doenjang made with different salts in SOS chromotest. As the results indicate, the various kinds of water and salt have had separate effects on the antimutagenic activity of doenjang; therefore, further research on various physiological functions of water or salt added traditional doenjang is needed.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.472-477
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• 2001

The study was carried out to evaluate the sensory characteristics and physiological effect of Korean soybean Paste (doenjang) added with Japanese apricot, garlic and ginger, and samjang. Garlic doenjang was shown to have a good taste, odor and color, but ginger doenjang was worse in the taste, odor and color than control doenjang in sensory evaluation. Japanese apricot doenjang and garlic doenjang had high scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, of which the IC$\_$50/ values were 93 and 94$\mu\textrm{g}$/$m\ell$, respectively. Five kinds of doenjang revealed antimutagenic activity against N-methyl-N’-nitro-N-nitrosoguanidine (MNNG), and especially, samjang showed 83% inhibition at the concentration of 5mg/plate. Samjang exhibited a strong antimutagenic activity(79%) against aflatoxin B$_1$,(AFB$_1$) in Salmonella typhimurium TA100. Ginger-, garlic- and Japanese apricot doenjangs also had high inhibitory effects against AFB$_1$. and the inhibition rates were 75, 55 and 51%, respectively. In SOS chromotest. samjang showed the highest antimutagenicity against MNNG, with 64% inhibition rate. These results demonstrated that samjang has strong a antimutagenic effect against MNNG and AFB$_1$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1164-1170
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• 2001

Antimutagenic and antimicrobial effects of cucumber extracts were investigated. Antimutagenic effects of cucumber extract against aflatoxin (AFB$_1$) as indirect mutagen and N-methyl-N'-nitro-N-nitrcsoguanidine (MNNG) as direct mutagen using the Ames assay system with Salmonella typhimurium TA100 were studied. 1.25~5.0% of methanol extract exhibited 11 ~ 17% of antimutagenity against AFB$_1$ and 46~85% of antimutagenity against MNNG. Among fractions of methanol extract, hexane fraction exhibited the highest antimutagenic effect against AFB$_1$ (89%) and butanol fraction exhibited the highest antimutagenic effect against MNNG (95%). Antimicrobial effects of cucumber extract were investigated on the eleven microorganisms. Methanol extract showed anitimicrobial effect on eight microorganisms. Among these tested microorganisms, Klebsiella pnemonia KCTC 2208, pseudomonas aeruginosa KCTC 2004 were the most sensitively inhibited with 13 mm clear zone on holo test. Hexane fraction showed anitimicrobial effect only on Vibrio parahaemolyticus KCTC 2471. Chloroform and ethyl acetate fractions showed a weak effect. V. parahaemolyticus showed the lowest minium inhibitory concentration (MIC) (500 ppm) among eleven tested microorganisms by methanol extract. Sterilization effect of 1% methanol extract on P. aeruginosa incubation is 10 times stronger than 0.5% methanol extract. It estimated to need 26 min for the sterilization of 90% P. aeruginosa cell counts by 1% methanol extract but 250 min by 0.5% methanol extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1248-1252
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• 2012

Potassium added with bamboo salt showed better antioxidative effects than bamboo salt, solar salt, or purified salt. It also showed inhibitory effects on the mutagenicity of MNNG (N-methyl-N-nitro-N-nitrosoguanidine) in a Salmonella Typhimurium TA100 tester strain. At concentrations of 1.25 and 2.5 mg/plate, potassium bamboo salt and bamboo salt showed weaker co-mutagenicity effects than either purified salt or solar salt, respectively. Anticancer effects of salts were evaluated using MTT assay in HCT-116 human colon carcinoma cells. At a 1% salt concentration, the growth inhibitory rate of potassium bamboo salt was 54%, higher than that of 1 time baked bamboo salt (36%). However, purified salt and solar salt showed relatively lower inhibitory effects of 19% and 23%, respectively. To determine the inhibitory mechanisms of potassium bamboo salt, the expression levels of Bax and Bcl-2 genes in HCT-116 cells were determined by RT-PCR. Potassium bamboo salt significantly increased Bax and decreased Bcl-2 expression levels unlike bamboo salt, purified salt, and solar salt (p<0.05). Therefore, addition of potassium to salt decreased co-mutagenicity and increased in vitro antioxidative and anticancer effects.