• 한국식품저장유통학회지
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• 제9권1호
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• pp.1-7
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• 2002

자연발효에 의해 다시마를 첨가하여 제조한 전통고추장에 대한 일반성분을 분석한 결과, 기존 고추장에 비해 대부분의 무기물 함량이 증가하였다. MNNG에 대한 항돌연변이 효과(200 $\mu\textrm{g}$/plate)에서 S. typhimurium TA100 균주에 대해 다시마 분말을 5% 첨가한 고추장이 다른 첨가 농도보다 높은 87.2%의 억제효과를 나타내었다. 4NQO에서는 5%의 다시마 분말 첨가 고추장이 S. typhimurium TA98 균주와 TA100 균주에 대해서 시료농도 200 $\mu\textrm{g}$/plate에서 각각 62.9%와 71.6%로 다른 첨가군보다 높은 억제효과를 나타내었다. B($\alpha$)P의 경우는 TA98, TA100 두균주에 대하여 다시마 분말 5% 첨가한 고추장이 각각 70.2%와 80.8%이었고, Trp-P-1에서는 각각 62.9%와 73.1%로 다른 첨가 농도보다 높은 억제효과를 나타내었다. 각종 암세포 성장 억제효과를 검토한 결과 추출물의 농도 1.0 mg/mL에서 KATOIII의 경우 78.6%, 그리고 HepG2의 경우 79.4%로 모두 5% 다시마 분말을 첨가한 고추장이 다른 농도에 비해 높은 억제효과를 나타내었다.

• 한국식품영양과학회지
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• 제31권2호
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• pp.322-328
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• 2002

메주와 다시마 그리고 이들 재료를 사용하여 자연발효에 의해 제조한 전통된장에 대한 일반성 분을 분석한 결과 기존의 된장에 비해 대부분의 무기물 함량이 증가하였다. 직접 변이원인 MNNG에 대한 항돌연변이 효과(200 $\mu\textrm{g}$/plate)에서 S. typhimurium TA100 균주에 대해 다시마 분말 5% 첨가 된장이 다른 첨가 농도보다 높은 97.0%의 억제효과를 나타내었다. 4NQO에서도 5%의 다시마 분말을 첨가한 된장이 S.typhimurium TA98 균주와 TA100 균주에 대해서 시료고농도 200 $\mu\textrm{g}$/plate에서 각각 60.2%와 69.1%로 다른 첨가군보다 높은 억제효과를 나타내었다. B($\alpha$)P에 대한 억제효과에 서는 시료의 농도 200$\mu\textrm{g}$/plate에서 TA98, TA100 두균주에 대하여 다시마 분말 5% 첨가 된장이 각각 71.7%와 87.3%로 다른 첨가군보다 높은 억제활성을 나타내었으며, TrP-P-1에 대해서는 두 균주가 시료고농도 200 $\mu\textrm{g}$/plate에서 각각 66.6%와 80.8%로 다른 다시마 분말 첨가 농도보다 높은 억제효과를 나타내었다. 암세포 성장억제 효과를 검토한 실험에서는 5% 다시마 분말을 첨가한 된장이 1 mg/mL에서는 A549가 55.4%, HepG2가 87.6% 그리고 KATOIII이 89.5%의 암세포 성장억제효과를 나타내었다.

• 한국자기학회지
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• 제14권1호
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• pp.25-28
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• 2004

Ta/NiFe/Cu/Co 구조의 Pseudo 스핀밸브 박막을 제작하여 NiFe, Cu, Co 각 층들의 두께변화에 따른 자기저항비(MR-ratio), 보자력, 자기 민감도(sensitivity), 반전자장(Switching Field)의 크기 등의 자기적 특성을 연구하였다. 각 층들의 두께를 변화시키면서 측정한 결과 Ta(4 nm)/NiFe(7.5 nm)/Cu(3 nm)/Co(5 nm)에서 최대 자기저항비 7.26 %를 얻을 수 있었다. 또한 각 층들의 독립적인 자화 과정을 통해 자기저항 특성을 조절할 수 있었다. 특히 Co의 두께를 변화시켜 자기저항비를 비교적 일정하게 유지하면서 보자력의 크기를 조절할 수 있음을 알게 되었다.

• 대한치과기공학회지
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• 제27권1호
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• pp.19-25
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• 2005

Ti6Al4V alloy have been mainly used as implant materials. Ti-6Al-4V alloy instead of pure Ti is being widely used as biomaterials has some characteristics such as high fatigue strength, tensile strength. But it has been reported recently that vanadium component expresses cytotoxicity and carcinogenicity and aluminium component is related with dementia of Alzheimer type. In order to overcome their detrimental effects, $\beta$-phase stabilizer Nb was chosen in the present study, in addition Ta and Hf were added to Ti-40wt.%Nb alloy to improve its mechanical properties. This paper was described the influence of heat treatment of Ti-40Nb alloys with 2wt%Ta, 2wt%Hf on the mechanical properties. Specimens of Ti alloys were melted in vacuum arc furnace and homogenized at 1050$^{\circ}C$ for 24 hr. and then were aged after solution heat treat at $\alpha+\beta$ and $\beta$ regions. The mechanical properties of Ti alloys were analysed by hardness test, tensile test, elongation test and SEM test. The results can be summarized as follows: 1. The mechanical properties Ti-40wt.%Nb were improved when 2wt.% Ta and 2wt.%Hf were added. 2. The higher tensile strength value and elongation at solution heat treat was higher than solution heat treat and then were aged.

• 한국표면공학회지
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• 제39권3호
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• pp.129-136
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• 2006

The high velocity oxy-fuel sprayed coatings of 38Ni-23Co-20Cr-11Al-3Y-5Ta, 25Ni-34Co-20Cr-11Al-3Y-2Re and 32Ni-34.5Co-22Cr-11Al-0.5Ir (in wt%) were oxidized at 1000 and $1100^{\circ}C$ in air in order to find the alloying effect of Ta, Re and Ir on the oxidation properties of the NiCoCrAlY-base coatings. The primary phase of the coatings was $Ni_3Al$. The oxides formed on the coatings consisted primarily of ${\alpha}-Al_2O_3$, together with some $CoCr_2O_4,\;CoAl_2O_4$, and $Al_5Y_3O_{12}$. Tantalum oxidized to $Ta_2O_5$ and $Ta_2O_{22}$. However, no oxides of Re and Ir were detected by XRD owing to their thermodynamic inertness and/or their small amount.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.376-377
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• 2006

This paper presents the characteristics of Ta-N thin film strain gauges that are suitable for harsh environemts, which were deposited on thermally oxidized Si substrates by DC reactive magnetronsputtering in an argon-nitrogen atmosphere (Ar-$N_2$ (4 ~ 16 %)). These films were annealed for 1 hr in $2{\times}10^{-6}$ Torr in a vacuum furnace with temperatures that ranged from 500 - $1000^{\circ}C$. The optimized deposition and annealing conditions of the Ta-N thin film strain gauges were determined using 8 % $N_2$ gas flow ratio and annealing at $900^{\circ}C$ for 1 hr. Under optimum formation conditions, the Ta-N thin film strain gauges obtained a high electrical resistivity, ${\rho}\;=\;768.93\;{\mu}{\Omega}{\cdot}cm$, a low temperature coefficient of resistance, $TCR\;=\;-84\;ppm/^{\circ}C$ and a high temporal stability with a good longitudinal gauge factor, GF=4.12. The fabricated Ta-N thin film strain gauges are expected to be used inmicromachined pressure sensors and load cells that are operable under harsh environments.

• Corrosion Science and Technology
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• 제8권4호
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• pp.162-169
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• 2009

Pure titanium and its alloys are drastically used in implant materials due to their excellent mechanical properties, high corrosion resistance and good biocompatibility. However, the widely used Ti-6Al-4V is found to release toxic ions (Al and V) into the body, leading to undesirable long-term effects. Ti-6Al-4V has much higher elastic modulus than cortical bone. Therefore, titanium alloys with low elastic modulus have been developed as biomaterials to minimize stress shielding. For this reason, Ti-30Ta-xZr alloy systems have been studied in this study. The Ti-30Ta containing Zr(5, 10 and 15 wt%) were 10 times melted to improve chemical homogeneity by using a vacuum furnace and then homogenized for 24 hrs at $1000^{\circ}C$. The specimens were cut and polished for corrosion test and Ti coating and then coated with TiN, respectively, by using DC magnetron sputtering method. The analyses of coated surface were carried out by field emission scanning electron microscope(FE-SEM). The electrochemical characteristics were examined using potentiodynamic (- 1500 mV~+ 2000 mV) and AC impedance spectroscopy(100 kHz~10 mHz) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The equiaxed structure was changed to needle-like structure with increasing Zr content. The surface defects and structures were covered with TiN/Ti coated layer. From the polarization behavior in 0.9% NaCl solution, The corrosion current density of Ti-30Ta-xZr alloys decreased as Zr content increased, whereas, the corrosion potential of Ti-30Ta-xZr alloys increased as Zr content increased. The corrosion resistance of TiN/Ti-coated Ti-30Ta-xZr alloys were higher than that of the TiN-coated Ti-30Ta-xZr alloys. From the AC impedance in 0.9% NaCl solution, polarization resistance($R_p$) value of TiN/Ti coated Ti-30Ta-xZr alloys showed higher than that of TiN-coated Ti-30Ta-xZr alloys.

• 한국식품영양학회지
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• 제14권4호
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• pp.329-332
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• 2001

The antimutagenic activity of resveratrol on the mutagenicity induced by Trp P-1 (3-amino-1,4-dime-thyl-5H-pyrido{4,3-b}indole) was studied using the Ames test with Salmonella typhimurium TA98 and 100. Trp P-1 showed strong mutagenecity in S. typhimurium TA98, but was higly decreased mutagenecity in S. typhimurium TA100. This result suggests that the mutagenecity of Trp P-1 can be mainly induced by the DNA lesions causing frame shift. Resveratrol itself did not show antibacterial effect upon 300 $\mu\textrm{g}$/assay. Resveratrol showed the strongest inhibitory effect with dose dependent manner on the mutagenicity induced by Trp P-1. The inhibition rates of resveratrol at concentration of 2, 10, 25, 50, 100, 300 $\mu\textrm{g}$/assay were 13%, 37%, 52%, 65%, 81%, 89%, respectively.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.197-202
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• 1995

The conditions for the $\beta$-fructofuranosidase production from alkalophilic, thermophilic Bacillus sp. TA-11 were investigated. The maximal enzyme production was obtained when the strain was cultured at 50$\circ$C for 36 hrs with batch culture in the optimal medium containing 1.0% sucrose, 0.6% yeast extract, 0.1% each of KH$_{2}$PO$_{4}$, K$_{2}$HP0$_{4}$, NaH$_{2}$PO$_{4}$, and initial pH 9.5, and the final enzyme activity under the above condition was 102 units per ml of cell free extract.

• 한국자기학회지
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• 제9권4호
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• pp.203-209
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• 1999

CoCrTa/Cr 자성박막의 Cr 하지층에 Mo와 Si을 첨가하여 제조한 박막의 자기적 성질에 미치는 Mo와 Si의 영향에 대하여 조사하였다. 증착시 사용된 장비는 DC magnetron sputtering system이었고, CoCrTa 자성층의 두께는 30.0$\AA$으로 Cr 하지층의 두께는 700$\AA$으로 고정하였으며 기판의 가열온도는 26$0^{\circ}C$이었다. CrMo 하지층의 박막이 순수한 Cr 하지층에 비하여 약 200 Oe의 보자력 증가를 나타내었다. 하지만 Si을 첨가하였을 경우엔 첨가량의 증가에 따라 보자력이 점차 감소하는 것으로 나타났다. CrMo 하지층에서는Mo를 첨가함에 따라 Cr 하지츠의 (200)면의 결정배향성이 증가하였고, Mo를 첨가한 Cr(200)과 CoCrTa(110)의lattice misfit가 Si을 첨가한 경우보다 작았고, 이것이 보자력 증가의 원인이었다.