• 한국균학회지
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• 제39권2호
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• pp.151-153
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• 2011

한국 전통 생 막걸리의 최적 저장 조건을 확립하기 위하여 먼저 전통 생 막걸리를 제조한 후 $4^{\circ}C$와 $20^{\circ}C$에 저장하면서 효모와 총 세균, 젖산균 수의 변화를 조사하였다. 효모는 $20^{\circ}C$에서 30일 저장 후 89%가 감소 되었으나, $4^{\circ}C$저장에서는 큰 변화가 없었다. 총 세균수는 $20^{\circ}C$에서 30일 저장시 98.0%가 감소 되었고 젖산균 역시 99%가 감소되었다. 그러나 $4^{\circ}C$저장에서는 65%미만의 낮은 감소를 보였다. 위의 결과와 관능검사 결과 등을 종합하였을 때 본 연구에서 제조한 생 막걸리는 $4^{\circ}C$와 $20^{\circ}C$에서 15일까지도 큰 품질저하 없이 음용할 수 있는 상태로 저장이 가능한 것으로 판단된다.

• Journal of Magnetics
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• 제10권1호
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• pp.5-9
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• 2005

Nanoparticles $Ni_{0.9}Zn_{0.1}Fe_2O_4$ is fabricated by a sol-gel method. The magnetic and structural properties of powders were investigated with XRD, SEM, Mossbauer spectroscopy, and VSM. $Ni_{0.9}Zn_{0.1}Fe_2O_4$ powders annealed at $300{^{\circ}C}$ have a spinel structure and behaved superparamagnetically. The estimated size of $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle is about 10 nm. The hyperfine fields at 13 K for the A and B patterns are found to be 533 and 507 kOe, respectively. The ZFC curves are rounded at the blocking temperature ($T_B$)and show a paramagnetic-like behavior above $T_B$. $T_B$ of $Ni_{0.9}Zn_{0.1}Fe_2O_4$ nanoparticle is about 250 K. Nanoparticles $Ni_{0.9}Zn_{0.1}Fe_2O_4$ annealed at 400 and $500{^{\circ}C}$ have a typical spinel structure and is ferrimagnetic in nature. The isomer shifts indicate that the iron ions were ferric at the tetrahedral (A) and the octahedral (B). The saturation magnetization of nanoparticles $Ni_{0.9}Zn_{0.1}Fe_2O_4$ annealed at 400 and $500{^{\circ}C}$ are 40 and 43 emu/g, respectively. The magnetic anisotropy constant of $Ni_{0.9}Zn_{0.1}Fe_2O_4$ annealed at $300{^{\circ}C}$ were calculated to be 1.6 ${\times}$ $10^6$ ergs/$cm^3$.

• 한국재료학회지
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• 제11권2호
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• pp.71-75
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• 2001

The reaction stability of nickel with side-wall materials of SiO$_2$ and Si$_3$N$_4$ on p-type 4"(100) Si substrate were investigated. Ni on 1300 $\AA$ thick SiO$_2$ and 500 $\AA$ - thick Si$_3$N$_4$ were deposited. Then the samples were annealed at 400, 500, 750 and 100$0^{\circ}C$ for 30min, and the residual Ni layer was removed by a wet process. The interface reaction stability was probed by AES depth Profiling. No reaction was observed at the Ni/SiO$_2$ and Ni/Si$_3$N$_4$, interfaces at 400 and 50$0^{\circ}C$. At 75$0^{\circ}C$, no reaction occurred at Ni/SiO$_2$ interface, while $NiO_x$ and Si$_3$N$_4$ interdiffused at Ni/Si$_3$N$_4$ interface. At 100$0^{\circ}C$, Ni layers on SiO$_2$ and Si$_3$N$_4$ oxidized into $NiO_x$ and then $NiO_x$ interacted with side-wall materials. Once $NiO_x$ was formed, it was not removed in wet etching process and easily diffused into sidewall materials, which could lead to bridge effect of gate-source/drain.

• 한국임상수의학회지
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• 제20권3호
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• pp.384-388
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• 2003

To establish the method of estrus induction using the injection of PGF$_2$$\alpha$ㆍ the 60 dairy cows treated by PGF$_2$$\alpha$ㆍ at 6, 8, 10, 12, 14, and 16 day of estrous cycle, recpectively. The plasma progesterone concentrations at day of injection of PGF$_2$$\alpha$ㆍ were $1.5\pm$1.3 (mean$\pm$SD) ng/ml at 6 days of estrous cycle, 3.7$\pm$1.4 ng/ml at 8 days, 6.5$\pm$1.8 ng/ml at 10 days, 7.9$\pm$2.0 ng/ml at 12 days, 6.5$\pm$2.5 ng/ml at 14 days, and 2.5$\pm$1.2 ng/m] at 16 days, respectively. The percentages of induction of estrus after PGF$_2$$\alpha$ㆍ treatment were 52.8% at 3th day after treatment, 21.7% at 4th day, 8.3% within 2th day, and ] 7.2% after 5th day, respectively. The percentages of cows conceived at first service after induction of estrus were 73.3% on 16 days of estrous cycle at treatment, 66.7% on 10 and 14 days, 63.3% on 8 and 12 days, and 53.3% on 6 day, respectively. The percentages of cows conceived on first service were 70.5% at 3th day after induction, 66.7% at 4th day and 65% at 5th day, respectively. These results suggest that the PGF$_2$$\alpha$ㆍ treatment at regressing stage of corpus luteum showed high induction of estrus and pregnancy rate, and there were high induction of estrus and pregnancy rate at 3th and 4th day after PGF$_2$$\alpha$ㆍ treatment.

• 대한수의학회지
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• 제32권3호
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• pp.347-356
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• 1992

In oriental medicine, Artemisia Iwayomogi(Compositae) has been used clinically for jaundice, hepatitis, liver cirrhosis etc. The purposes of present study were to examine pharmacological effects of Artemisia lwayomogi water extract(AIWE) on weights of body, liver, kidney, spleen and adrenal, and on biochemical parameters (activities of AST, ALT and LDH, contents of cholesterol and triacylglycerol, and levels of hepatic lipid peroxide) against hepatic injury by carbon tetrachloride($CCl_4$) in rats. The results were as follow; 1. Body weights were reduced by $CCl_4$. In AIWE pretreatment groups, reduction of body weights was inhibited at 48 hours. Increased liver weights by $CCl_4$ were reduced in proportion to numbers of treatment of AIWE in AIWE pre- and posttreatment groups. Increased kidney weights by $CCl_4$ were reduced in AIWE pretreatment groups at 72 hours. Increased weights of spleen and adrenal by $CCl_4$ were not affected by AIWE treament. 2. Increased AST activities by $CCl_4$ were significantly (p<0.05) decreased in AIWE posttreatment groups at 48 and 72 hours. Increased ALT activities by $CCl_4$ were significantly(p<0.05) decreased in AIWE posttreatment groups at 48 hours. Increased LDH activities by $CCl_4$ were very significantly (p<0.01, p<0.001) decreased in AIWE posttreatment groups at 48 and 72 hours, respectively. 3. Increased cholesterol contents by $CCl_4$ were significantly (p<0.05) decreased in AIWE posttreatment groups at 24 and 48 hours. Decreased triacylglycerol contents by $CCl_4$ were significantly (p<0.05) increased in AIWE posttreatment at 48 and 72 hours. 4. Increased hepatic lipid peroxide levels by $CCl_4$ were significantly (p<0.05, p<0.01) decreased in AIWE posttreatment groups at 48 and 72 hours, respectively. In conclusion, AIWE did not affect normal liver function and had property of antioxidant, due to reduced lipid peroxidation by $CCl_4$. AIWE seems to have hepatoprotective effects rather than direct preventive effects to $CCl_4$-induced necrotic degeneration of liver cell, cholestasis and damages in metabolism of lipid.

• 한국환경과학회지
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• 제5권2호
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• pp.243-252
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• 1996

미국 New Jersey주에서 채취한 4종류의 토양사료를 이용하여 토양에서 카드뮴 흡착과 치환성양이온의 탈착에 미치는 pH와 유기뮬함령의 영향을 조사하였다. 카드뮴용액으로는 $1\times10^{-5}$M,$1\times10^{-4}$M, $2\times10^{-4}$M, $3\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용하였고, 흡착평형시의 토양용액의 pH는 4.0,5.5, 7.0, 8.5로 맞추었다. 카드뮴흡착등온선의 기울기는 토양용액의 pH가 증가하였으며, partition coefficient($K_4$)도 용액의 pH가 증가할수록 크게 증가하였다. 또한 Langmuir흡착방정식에 의하여 구한 카드뮴대흡착량도 용액의 pH가 높은 경구가 낮은 경우보다 훨씬 많았다. $1\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용한 실험에서 유기물함량과 partition coefficient사이의 correltion coefficient($r^2$)는 용액의 pH가 4.0인 경우의 0.3027에서 pH가 8.5인 경우의 0.9964로 증가하였으며, $2\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용한 실험에서는 pH가 4.0인 경우의 0.2093에서 pH가 8.5인 경우의 0.9657로 증가하였다. 칼슘과 마그네슘의 탈착량은 토양용액의 pH가 증가할수롱, 흡착된 카드뮴의 양이 증가할수록 감소하였다.

• 원예과학기술지
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• 제30권5호
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• pp.519-526
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• 2012

혐기처리 녹차를 알루미늄 포장에 보관하여 상온, $4^{\circ}C$, $-10^{\circ}C$에 저장 시 품질관련 화학성분인 총질소, 총아미노산, 탄닌, 카페인, 엽록소, 비타민 C 및 지방산은 저장기간이 길어질수록 함량이 감소되었다. 각 성분의 함량 감소폭은 $-10^{\circ}C$ 저장이 상온, $4^{\circ}C$에 비해 적었으며, 함량 감소는 상온에 비해 8개월, $4^{\circ}C$에 비해서는 4개월 정도 지연되었다. 저장 시녹색을 나타내는 'a'값이 감소할수록 품질이 저하되는데, 혐기처리 녹차의 표면 녹색을 나타내는 'a'값은 12개월 저장 시 상온 > $4^{\circ}C$ > $-10^{\circ}C$ 순으로 저장온도가 높을수록 녹색이 감소됨을 알 수 있었다. 형상, 향, 맛 등으로 평가하는 관능평가는 100점 만점에 점수가 낮을수록 품질이 저하되며, 저장온도에 따라 혐기처리 녹차의 품질이 상이하였는데 $-10^{\circ}C$ 12개월 저장 시 80점, $4^{\circ}C$ 8개월 81.1점, 상온 4개월 80.4점으로 저장온도가 낮을수록 품질이 양호하였다. 따라서 본 연구의 내용을 종합한 결과, $-10^{\circ}C$를 혐기처리 녹차의 가장 효과적인 저장온도로 제시하고자 한다.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.104-111
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• 2010

The heterogeneous electron transfer at $SiMo_{12}O_{40}^{4-}$ monolayers on GC, HOPG, and Au electrode surfaces are investigated using cyclic voltammetric and electrochemical impedance spectroscopic (EIS) methods. The electron transfer of negatively charged $Fe(CN)_6^{3-}$ species is retarded at $SiMo_{12}O_{40}^{4-}$-modified electrode surfaces, while that of positively charged $Ru(NH_3)_6^{3+}$species is accelerated at the modified surfaces. This is due to the electrostatic interactions between $SiMo_{12}O_{40}^{4-}$ layers on surfaces and charged redox species. The electron transfer kinetics of a neutral redox species, 1,1‘-ferrocenedimethanol (FDM), is not affected by the modification of electrode surfaces with $SiMo_{12}O_{40}^{4-}$, indicating the $SiMo_{12}O_{40}^{4-}$ monolayers do not impart barriers to electron transfer of neutral redox species. This is different from the case of thiolate SAMs which always add barriers to electron transfer. The effect of $SiMo_{12}O_{40}^{4-}$ layers on the electron transfer of charged redox species is dependent on the kind of electrodes, where HOPG surfaces exhibit marked effects. Possible mechanisms responsible for different electron transfer behaviors at $SiMo_{12}O_{40}^{4-}$ layers are proposed.

• 한국항공우주학회지
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• 제34권10호
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• pp.16-23
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• 2006

저 레이놀즈수에서 NACA 0012 에어포일의 경계층 거동에 관한 연구가 터빈 블레이드와 초소형 비행체에서 적용될 수 있는 경계층을 파악하기 위하여 수행되었다. 레이놀즈수 Re=$2.3{\times}10^4$, $3.3{\times}10^4$, $4.8{\times}10^4$과 정적 받음각 ${\alpha}$=$0^{\circ}$, $3^{\circ}$, $6^{\circ}$에서 경계층을 측정하기 위해 열선 풍속계가 사용되었다. 연구결과는 정적 받음각 =$0^{\circ}$에서는 층류 경계층이 에어포일 표면에 부착되며, 정적 받음각 $3^{\circ}$에서는 경계층 층류 분리가 발생된 것을 보여준다. 더욱이 본 연구에서 경계층 재부착 현상은 정적 받음각 $6^{\circ}$에서 레이놀즈수 $3.3{\times}10^4$와 $4.8{\times}10^4$에서 발생된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.444-447
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• 2000

The spinel L $i_{1-x}$ M $n_2$ $O_4$has been synthesized by the solid-state reaction. L $i_{l-x}$M $n_2$ $O_4$which includes a mixture of LiOH . $H_2O$ and Mn $O_2$prepared by preliminary heating at 35$0^{\circ}C$ for 12hr. L $i_{l-x}$M $n_2$ $O_4$fired at temperature range from 75$0^{\circ}C$ for 48hr. The structure and the electrochemical characteristics of spinel to L $i_{1-x}$ M $n_2$ $O_4$which is fabricated by changing sintering condition from starting materials are investigated. The cyclic voltammetric measurement was performed using 3 electrode cells. Electrode specific capacity and cycle life behavior were tested in a 3.0~4.2V range at a constant current density of 0.45mA/c $m^2$. To improve the cycle performance of spinel L $i_{l-x}$M $n_2$ $O_4$as the cathode of 4V class lithium secondary batteries, spinel phases L $i_{1-x}$ M $n_2$ $O_4$were Prepared at various lithium. The results showed that discharge capacity of L $i_{l-x}$M $n_2$ $O_4$varied at lithium quantity decrease with increasing lithium add quantity. The discharge capacities of L $i_{0.925}$M $n_2$ $O_4$and LiM $n_2$ $O_4$revealed 108 and 117mAh/g, respectively.spectively.y.