• Title/Summary/Keyword: $MgB_6$

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The Fabrication of Low Temperature Firing Substrate of $Li_2O-MgO-MgF_2-SiO_2-B_2O_3$ system

  • Park, Jung-Houn;Park, Dae-Hyun;Kang, Won-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.4
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    • pp.35-39
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    • 1999
  • The $Li_2O-MgO-MgF_2-SiO_2$glasses with addition of $B_2O_3$ were investigated in order to make glass-ceramics for low temperature firing substrate. Glasses were made by melting at $1450^{\circ}C$ in the electronic furnace and crystallized at $750^{\circ}C$. The crystal phases were polycrystalline of lithium boron fluorphlogopite and lithium fluorhectorite. The crystal shape was chanced to granule type from needle type with increasing $B_2O_3$ content. Average particle size of the glass-ceramics after water swelling was 3.77$\mu\textrm{m}$. The optimum sintering temperature and sintering shrinkage of the substrate were $900^{\circ}C$ and 13.4%, respectively.

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Enhanced Immune Activity and Cytotoxicity of Artemisia capillaris Thunb. Extracts against Human Cell Lines (사철쑥 추출물의 면역세포의 생육증진 및 세포독성)

  • Lee, Mi-Kyoung;Choi, Geun-Pyo;Ryu, Lee-Ha;Lee, Gang-Yoon;Yu, Chang-Yeon;Lee, Hyeon-Yong
    • Korean Journal of Medicinal Crop Science
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    • v.12 no.1
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    • pp.36-42
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    • 2004
  • The immune activation and anticancer activities of the water and ethanol extracts from Artemisia capillaris Thunb. were studied. The growth of human hepatocarcinoma and human gastric cancer cell was inhibited by the addition of $1.0\;mg/m{\ell}$ of the water extract, by about 77% and 95%, respectively. The growth of human breast cancer cells was also inhibited by addition of $0.5\;mg/m{\ell}$ of both water and ethanol extracts by 88%. The growth of human normal lung cell, HEL299 was inhibited by 15% indicating very low cytotoxicity of both extracts. Overall selectivity of the both extracts on several human cancer cell line was over 2.5. The growth of both human B and T cells was enhanced up to 1.6 to 2.1 times by adding the ethanol extracts. The secretion of cytokines, $TNF-{\alpha}$ and IL-6, from human B cells was also increased showing $68\;pg/m{\ell}$ and $67\;pg/m{\ell}$, respectively, compared to $35{\sim}40\;pg/m{\ell}$ of the control. In terms of the immune activity, there was not much difference between water and ethanol extracts of Artemisia capillaris Thunb. It implies that the extraction solvent could not differ the biological activities of the extracts. Based on these results, Artemisia capillaris Thunb. can be developed into a potentially useful cancer chemoprentive agent.

Influence of the Heat-treatment Temperature on the Critical Properties of $C_4H_6O_5$-doped $MgB_2/Fe$ Wire ($C_4H_6O_5$ 도핑된 $MgB_2/Fe$ 선재의 임계특성에 대한 열처리 온도의 영향)

  • Jun, Byung-Hyuk;Kim, Jung-Ho;Dou, Shi Xue;Kim, Chan-Joong
    • Progress in Superconductivity
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    • v.9 no.1
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    • pp.62-67
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    • 2007
  • The effects of the heat-treatment temperature on the carbon (C) substitution amount, full width at half maximum (FWHM) value, critical temperature ($T_c$), critical current density ($J_c$) have been investigated for 10 wt % malic acid ($C_4H_6O_5$)-doped $MgB_2/Fe$ wires. All the samples were fabricated by the in-situ powder-in-tube (PIT) method and heat-treated within a temperature range of $650^{\circ}C$ to $1000^{\circ}C$. As the heat-treatment temperature increased, it seemed that the lattice distortion was increased by a more active C substitution into the boron sites from the malic acid addition. These increased electron scattering defects seemed to enhance the $J_c-H$ properties in spite of an improvement in the crystallinity, such as a decrease of the FWHM value and an increase of the $T_c$. Compared to the un-doped wire heat-treated at $650^{\circ}C$ for 30 min, the $J_c$ was enhanced by the C doping in a high-field regime. The wire heat-treated at $900^{\circ}C$ resulted in a higher magnetic $J_c$ of approximately $10^4\;A/cm^2$ at 5 K and 8 T.

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Studies on Simultaneous Determination of Chlorophyll a and b, Pheophorbide a, and $\beta-Carotene$ in Chlorella and Spirulina Products (클로렐라 및 스피루리나제품에 함유된 엽록소 a, b, 페오포르바이드 a 및 $\beta$-카로틴의 동시분석법에 관한 연구)

  • Lee Young Ja;Kim So Hee;Kim Jin-Sook;Han Jeong A;Seo Hae Jeom;Lim Hyo Jeong;Choi Soo Young
    • Journal of Food Hygiene and Safety
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    • v.20 no.3
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    • pp.141-146
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    • 2005
  • A simple and sensitive analysis method based on reverse phase (RP) HPLC with UV detector was developed for simultaneous determination of chlorophyll a and b, pheophorbide a and $\beta-Carotene$ in Chlorella and Spirulina products. For added concentration $(50\;\mug/ml)$ of chlorophyll a and b, pheophorbide a and $\beta-Carotene$, recoveries of those were 70.3, 71.6, 60.1 and $90.5\%$, respectively, with relative standard deviations of 2.8,6.0, 10.6 and $10.4\%$. Limit of detection and quantification had ranges of $0.1\sim1.0\;\mug/ml$ and $0.2\sim2.0\;\mug/ml$, respectively. Calibration curve was linear with correlation coefficient of 0.995 for chlorophyll a and b, pheophorbide a and $\beta-Carotene$. Results of simultaneous determination in Chlorella and Spirulina products were showed ranges of $121.g\sim543.0\;\mug/ml$ for chlorophyll a,$0.6\sim160.0\;\mug/ml$ for chlorophyll b, $19.2\sim60.3\;\mug/ml$ for pheophorbide a and $383.6\sim1713.7\;\mug/ml$ for $\beta-Carotene$, respectively. Chlorophyll b contents in Chlorella products were detected above 30 times level to those in Spirulina products. $\beta-Carotene$ contents in Spirulina products were detected 2.7 times level to those in Chlorella products.

Crystal growth and optical absorption of $Mg_{0.16}Zn_{0.84}Te:Co $ single crystal ($Mg_{0.16}Zn_{0.84}Te:Co $단결정 성장과 광흡수 특성)

  • 정상조
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.4
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    • pp.548-554
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    • 1997
  • The single crystal of $Mg_{0.16}Zn_{0.84}$Te:Co(Co:0.01 mole%) was grown by vertical Bridgman method. The crystal structure of $Mg_{0.16}Zn$_{0.84}$Te:Co and optical absorption properties of this compound were studied. The grown single crystal has a cubic structure and a lattice constant a=6.1422 $\AA$ were determined by X-ray diffraction. As a result of the optical absorption spectra of $Mg_{0.16}Zn_{0.84}$Te:Co, the intracenter transitions due to $Co^{2+}$ ions were detected for $A-band:^4A_2(^4F){\to}^4T_2(^4F),\; B-band:^4A_2(^4F){\to}^4T_1(^4F), C- band:^4A_2(^4F){\to}^4T_1(^4P)$.The charge transfer transition near the absorption edge was observed in the wavelength range of 550 to 770 nm. According to the crystal field theory, the crystal field parameter(Dq) and the Racah parameter(B) were determined.

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Baseline Dietary Behaviors of Children for Nutritional Management Programs at Child Care Centers in Korea (영유아 보육시설의 영양관리 시범사업(I): 유아의 식생활 현황)

  • 정효지;이난희;최영선;조성희
    • Journal of Nutrition and Health
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    • v.33 no.8
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    • pp.890-900
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    • 2000
  • The aim of this investigation was to collect the baseline data about growth, dietary behaviors, nutrient intakes and dietary quality of children at child care centers for planning nutritional management program. The dietary intakes were measured by weighing method for intakes at child care centers and by dietary records by children\\`s mothers for intakes at home. The weight and height were measured and calculated z-scores by using standard of the same age groups. The children were 163 boys and 168 girls and the mean age were 55.6 months(12-78 months) and 56.0 months(16-78 months). respectively. The Z-score for height(0.33) and weight(0. 11) showed that the growth of children were above average. Nutrients intakes such s energy, protein, fiber, iron, sodium, potassium, vitamin A, vitamin B$_1$, vitamin C, niacin of boys from lunch and snack at day care centers were significantly higher than those of girls, and the meals at child care centers provided 20-37% of RDAs. The daily energy intakes were 1332.2kcal(83.1% RDA), protein 44. 26g(109.3% RDA), calcium 437.73mg(72.4% RDA), iron 7.24mg(72.4% RDA), vitamin A 459.6RE(113.1% RDA),vitamin B$_1$ 0.74mg(93.4% RDA), vitamin B$_2$0.79mg(79.7% RDA), niacin 7.66mg(69.9% RDA) and vitamin C 56.84mg(142.1% RDA). The nutrients which more than 50% of subjects ate less than 75% RDA were calcium, iron, niacin, and vitamin B$_2$.The average mean adequacy ratio was 0.80 and mean dietary variety score was 22.42, and those are positively correlated to % RDA of nutrient intakes. In summary, the children using child care centers consumed most nutrients below level of RDA and the nutritional management program at child care center is required to enhance the nutritional status of them. (Korean J Nutrition 33(8) : 890-900, 2000)

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Desmutagenic Effect of Extracts Obtained from Seaweeds (해조류의 항돌연변이 효과)

  • RYU Beung-Ho;CHI Bong-Ho;KIM Dong-Seuk;HA Mi-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.5
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    • pp.502-508
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    • 1986
  • Extracts of six seaweeds obtained from solvents such as water, methanol, hexane and ethyl ether have been tested for desmutagenic activities in the Salmonella typhimurium/microsome systems. Water extracts obtained from tangle, sea-tangle, and gompi were moderately effective on the mutagenicity of Trp-P-2 and aflatoxin $B_1$. Methanol extracts of sea-tangle and gompi were effective against Trp-p-2, and all samples of methanol extracts were very effective from 1.0mg to 2.0mg per plate on the mutagenicity of MeIQ and aflatoxin $B_1$. Hexane extracts of tangle, ses-tangle, gompi and sea-straghorn were very effective on the mutagenicity of Trp-p-2, MeIQ and aflatoxin $B_1$ except laver and green laver. Ethyl ether extracts of gompi and sea-straghorn were most effective from 1.0mg to 2.0mg per plate on the mutagenicity of Trp-P-2. Especially, ethyl ether extracts of all samples were great effective on the mutagenicity of MeIQ and aflatoxin $B_1$.

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Assessment of vitamin $B_6$ status in Korean patients with newly diagnosed type 2 diabetes

  • Ahn, Hee-Jung;Min, Kyung-Wan;Cho, Youn-Ok
    • Nutrition Research and Practice
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    • v.5 no.1
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    • pp.34-39
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    • 2011
  • The purpose of this study was to assess vitamin $B_6$ intake and status in Korean patients with newly diagnosed type 2 diabetes. Sixty-four patients with newly diagnosed type 2 diabetes and 8-11% glycated hemoglobin (A1C), along with 28 age-matched non-diabetic subjects, participated. Dietary vitamin $B_6$ intake was estimated by the 24 hour recall method and plasma pyridoxal 5'-phosphate (PLP) was measured. There was a significant difference in daily total calorie intake between the diabetic and non-diabetic groups ($1,917{\pm}376$ vs $2,093{\pm}311\;kcal$). There were no differences in intake of total vitamin $B_6$ ($2.51{\pm}0.91$ vs $2.53{\pm}0.81\;mg/d$) or vitamin $B_6$/1,000 kcal ($1.31{\pm}0.42$ vs $1.20{\pm}0.32\;mg$) between the diabetic and non-diabetic groups, and I intakes of total vitamin $B_6$ were above the Korean RDA in both groups ($180.0{\pm}57.9$ vs $179.0{\pm}65.4$). There was a higher percentage of diabetic subjects whose plasma PLP concentration was < 30 nmol/L compared to non-diabetic group. Plasma PLP levels tended to be lower in the diabetic subjects than in the non-diabetic subjects, although the difference was not statistically significant due to a large standard deviation ($80.0{\pm}61.2\;nmol/L$ vs $68.2{\pm}38.5\;nmol/L$). Nevertheless, plasma PLP levels should be monitored in pre-diabetic patients with diabetic risk factors as well as in newly diagnosed diabetic patients for long-term management of diabetes, even though this factor is not a major risk factor that contributes to the development of degenerative complications in certain patients.

Studies on the Penetration, Diffusion Ability and Effect of Insects Control Using the Methyl Bromide in the Vertical Silo (수직사이로에 있어 MB훈증제의 침투확산성 및 살충효과 시험)

  • Hah J.K.;Kim J.T.;CHO N.K.;Kim B.H.
    • Korean journal of applied entomology
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    • v.20 no.4 s.49
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    • pp.212-216
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    • 1981
  • This experiment was carried out to investigate the penetration velocity and diffusion ability of methyl bromide fumigants under the condition of natural gravity, and the effect of in control of yellow corn in the vortical silo. The results were as fallows 1. The methyl bromide remainded concentration on the surface of the vertical silo was rapidly reduced from over 100mg/l to under 20mg/l, within 2 hours after supplying methyl bromide fumigant 2. Even 3m depth place from the surface of the vertical silo filled with yellolw corn was well penetrated within 30 minutes, but its remained methyl bromide gas was reduced gradually from over 100mg/l to 30mg/l after 12 hours duration. 5. In case of 13m place tile penetration ability of methyl bromide was over 100mg/l within one hour and kept the same concentration of it for 12 hours, its remainded methyl bromide preserved over 40mg/l until 48 duration time. 4. Less methyl bromide gas was detected at the bottom place than 3m and 13m depth of the vertical silo. It showed bellow 20mg/l of methyl bromide gas only through the whole duration time. 5. Comparing to the vertical penetration velocity of mehtyl bromide gas, the horizontal diffusion ability was not so good. Therefore, remained methyl bromide gas of 3m depth at the wall side of silo was about half than that of center circle where the nearer place from the methyl bromide supplying point, and the methyl bromide gas of 13m depth placed center circle was detected about 15 to 20 times than that of wall side. 6. For the purpose of examining the mortality of methyl bromide, the testing insects (Lesser Rice weevil and confused flour beetle) placed on the surface and bottom side of the silo were killed completely after 24 hrs fumigation, and the same results showed also at the 3m, 7m and 13m depth after 48 hrs fumigation.

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Screening of biological activities of the extracts from Rubus coreanus Miq (복분자 열매 추출물의 유용 생리활성 탐색)

  • Lee, Mi-Kyoung;Lee, Hyun-Soo;Choi, Geun-Pyo;Oh, Deog-Hwan;Kim, Jong-Dai;Yu, Chang-Yeon;Lee, Hyeon-Yong
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.1
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    • pp.5-12
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    • 2003
  • The biological activities of extracts from Rubus coreanus Miq. were compared. About 70% of the growth of human hepatocarcinoma and 79% of human gastric cancer cell was inhibited in adding 1.0 mg/ml of the extracts of Rubus coreanus Miq. respectively. The growth of human breast cancer cells was also inhibited in adding 1.0 mg/ml of the extracts as well as 78% of the human cancer cells. It was proved that the growth of human normal lung cell, scored as 15% for the extracts. Overall selectivity of the extracts on several human cancer cell line was over 5, which is higher than those from the Rubus coreanus Miq. The growth of both human immune B and T cells was enhanced up to 1.4 to 1.8 times by adding the extracts, compared to the controls. The secretion of tumor necrosis $factor-alpha(TNF-{\alpha})$ from T cell was also increased up to 78.8 pg/ml in adding the ethanol extract (0.5 mg/ml). Ethanol extract also increased up to about 70 pg/ml of interleukin-6(IL-6) from B cell. For screening regulate function of blood pressure, angiotensin converting enzyme(ACE) activity was inhibited up to 25% by adding the ethanol extract (1.0 mg/ml). In testing the hypoglycemic activity, 20% of ${\alpha}-glucosidase$ activity was inhibited for the extracts (0.5 mg/ml). GST activity was increased in the range of 1.2 to 1.6 times by adding extracts.