• 제목/요약/키워드: $MgB_4$

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Comparison of Vitamin B1, B2, and Niacin Contents According to the Cultivars of Apple, Peach and Strawberry (사과, 복숭아, 딸기 품종에 따른 비타민 B1, B2 및 나이아신 함량 비교)

  • Yoon, Sung Ran;Ryu, Jung A;Chung, Namhyeok;Jang, Kil Su;Kim, Jong Soo
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.4
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    • pp.1119-1127
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    • 2019
  • This study analyzes the content of niacin, B1, and B2, which are among the water-soluble vitamin B group, in cultivars of the commonly consumed agricultural products of apples, peaches, nectarines and strawberries to compare content differences and to use results as base material for the Korean Food Composition Table. While the vitamin B1 content of apples according to different cultivars was found to be within the ranges of 0.063-0.208 mg/100g, and the content of vitamin B2 was found to be within the value ranges of 0.006-0.031 mg/100g, no niacin was found. The vitamin B1 content of peaches and nectarines according to different cultivars was found to be within the value ranges of 0.014-0.276 mg/100g, the content of vitamin B2 was found to be within he value ranges of 0.019-0.042 mg/100g, and niacin content was found to be within the value ranges of 0.298-1.096 mg/100g. The vitamin B1 content of strawberries according to cultivars was found to be within the value ranges of 0.112-0.394 mg/100g, the content of vitamin B2 was found to within the value ranges of 0.001-0.027 mg/100g, and niacin content was found to be within the value ranges of 0.388-0.809 mg/100g. Therefore, when nutrient composition analysis databases for the fruits of apples, peaches, and strawberries are constructed, cultivar factors must be put into consideration. In addition, differences can be found according to fruit harvest times, cultivation methods, and environmental factors, so related additional is needed.

A Quality Comparative Study on the Tomato Product in Korean Markets (I) - An Analytical Report on the Nutritive Ingredients and the Standardization of Duality of Tomato Katchup Marketed - (시판(市販) 도마도 가공품(加工品)의 품질(品質) 비교연구(比較硏究)(I) - 도마도 켓찹을 중심(中心)으로 -)

  • Rho, Sook-Nyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.8 no.1
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    • pp.9-14
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    • 1979
  • The consumption of catchup is increasing due to the raising of income level and food industry and westernization of dietary life followed by economic growth. In this paper I picked up three kinds of food produced by two foreign food companies and three kinds of food by two domestic companies. The average results by experimentation on the nutritive ingredients and the standard quality was as follows; A. Nutritve ingredients; 1) Water content a) Domestic 68.3% b) Foreign 69.1% 2) Protein content a) Domestic 2.2 g b) Foreign 2.1 g 3) Fat content a) Domestic 0.1 g b) Foreign 0.1 g 4) Carbohydrate content a) Domestic 25.1 g b) Foreign 24.6 g 5) Mineral content (Ash) a) Domestic 4.4 g b) Foreign 3.9 g 6) Calcium content a) Domestic 33.5 mg b) Foreign 24.2 mg 7) Phosphorus content a) Domestic 16.1 mg b) Foreign 24.2 mg 8) Vitamin C content a) Domestic 14.6mg b) Foreign 16.0 mg B. Standard quality 1) Remains after evaporation a) Domestic 41.7% b) Foreign 38.4% 2) Free mineral acid content a) Domestic none b) Foreign none 3) Tar chromatophore a) Domestic $trace(Acid)^+$ b) Foreign none 4) Heavy metalic $elements^*$ 5) Sodium chloride content a) Domestic 3.3% b) Foreign 3.3% 6) pH level a) Domestic 3.83 b) Foreign 3.76 + The tar chromatophore elements could not be accurately measured by chromatography. * The heavy metalic elements were both under safety levels in the domestic and foreign products.

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Effect of MgB6 Addition on Synthesis of Hexagonal Boron Nitride (Hexagonal Boron Nitride의 합성에 있어서 MgB6 첨가의 효과)

  • Lee, Dae-Jin;Jee, Mi-Jung;Choi, Byung-Hyun;Lee, Mi-Jai;Cho, Nam-Hee;Cha, Mi-Sun
    • Journal of the Korean Ceramic Society
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    • v.46 no.1
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    • pp.53-57
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    • 2009
  • The h-BN powder was synthesized by amorphous $B_2O_3$ and activated carbon at $1550^{\circ}C$ in nitrogen atmosphere, whose properties were examined according to $MgB_6$ addition. Amount of $MgB_6$ addition was varied in the range of $0{\sim}$10\;wt% of the initial mixture. It was observed that $MgB_6$ addition led to an increase in the amount and the grain size of h-BN and decrease in the amount of $B_4C$ forming. When $MgB_6$ added 5 wt%, the amount and crystallinity of h-BN increased as the holding time at the synthesis temperature was prolonged. It was also confirmed that the regularity of three-dimensional ordering of h-BN increases.

Callus Induction and Plant Regeneration in Hordeum spontaneum (Hordeum spontaneum에서의 callus 유기와 식물체 양생)

  • Jong-Yol Choi
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.4
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    • pp.466-470
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    • 1987
  • Immature embryos of Hordeum spontaneum were cultured on B5 and CI medium (Cheng's modified MS) to induce callus formation. CI media containing lmg/$\ell$ and 2mg/$\ell$ 2,4-D were more effective than B5 medium with lmg/$\ell$ 2,4-D for the initiation of callus. Total 883 calli were induced from 1,060 immature embryos plated. Callus induction frequency was 83%. Calli were transferred to differentiation media after one subculture to regenerate plants. Forty six plants were regenerated from 608 calli. Seventeen plants were chlorophyll deficient. There was no significant difference for plant regeneration among genotypes and media effects in calli which had been induced from immature embryos of seven types of trisomies. The overall regeneration frequency was 7.6%.

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Growth of superconducting $MgB_2$ fibers for wire applications

  • Kim J. H.;Yoon H. R.;Jo W.
    • Progress in Superconductivity and Cryogenics
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    • v.7 no.4
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    • pp.1-3
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    • 2005
  • Superconducting $MgB_2$ fibers are in-situ grown by a diffusion method. The fibers are prepared by exposing B filaments to Mg vapor inside a folded Ta foil over a wide range of temperature and growth time. The materials are sealed inside a quartz tube by gas welding. The as - grown fibers are characterized by scanning electron microscopy and energy dispersive x - ray analysis. The fibers have a diameter of about $110{\mu}m$. Surface morphology of the fibers looks dependent on growth temperature and mixing ratio of Mg and B. Radial distribution of Mg ions into B is observed and analyzed over the cross - sectional area. Transport properties of the $MgB_2$ fibers are examined by a physical property measurement system. The $MgB_2$ fibers grown at $900^{\circ}C$ for 2 hours show a superconducting transition at 39.8K with ${\Delta}T_c<$ 2.0 K. Resistance at room temperature $MgB_2$ is 3.745 $\Omega$ and residual resistivity ratio (RRR) is estimated as 4.723.

Comparison of superconducting generator with 2G HTS and MgB2 wires

  • Park, S.I.;Kim, J.H.;Le, T.D.;Kim, H.M.
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.4
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    • pp.48-52
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    • 2013
  • This paper compares the features of second generation (2G) High Temperature Superconducting (HTS) field coil with those of magnesium diboride ($MgB_2$) field coil for a 10 MW class superconducting generator. Both coils can function effectively in their respective magnetic flux density range: 10-12 T for 2G HTS field coil, 2 T for $MgB_2$ superconducting field coil. Even though some leading researchers have been developing 10 MW class superconducting generator with 2G HTS field coil, other research groups have begun to focus on $MgB_2$ wire, which is more economical and suitable for mass production. However 2G HTS wire is still appealing in functions such as in-field property and critical temperature, it shows higher in-field property and critical temperature than $MgB_2$ wire.

Culture Characteristics on the Activity of ${\gamma}-Glutamyltranspeptidase{\;}({\gamma}-GTP)$ by Bacillus subtilis Fusant (배양조건이 Bacillus subtilis 융합주의 ${\gamma}-Glutamyltranspeptidase{\;}({\gamma}-GTP)$ 활성에 미치는 영향)

  • 김관필;김성호;정낙현
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.3
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    • pp.395-402
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    • 2001
  • A fusant FG-21 was selected on the basis of higher ${\gamma}-GTP$ activity following fusion process between SM-2 and SM-10 of Bacillus subtilis mutants. ${\gamma}-GTP$ activity of the mutant FG-21 was increased up to 612 U/mL when grown for 36 hr at $37^{\circ}C$ in culture media containing 1% glycerol 1% glycerol, 1% peptone, 0.1% citric acid, 5 mM $K_2HPO_4$, 1 mM $FeCl_3$, 1 mM $MgCl_2$, 1 mM $NH_4Cl$, pH 7.0. In fusnat FG-21, the ratio of protein to total sugar contents for biopolymer A was 38 to 59. for biopolymer B from parental strains it was 19 to 78. Fructose contents determined by HPLC were $573.7\;\mu\textrm{g}/mg\;and\;764.4\;\mu\textrm{g}/mg$ for biopolymer A and B, respectively. And glutamic acid content were $163.7\;\mu\textrm{g}/mg\;and\;94.6\;\mu\textrm{g}/mg$ for biopolymer A and B, respectively. In fusant FG-21, the ratio of fructose to glutamic acid contents for biopolymer A was 78 to 22. For biopolymer B from parental strains it was 89 to 11.

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Quality Characteristics of Rice $Makgeolli$ Prepared by Mashing Types (담금유형에 따른 쌀 막걸리 술덧의 품질특성)

  • Park, Chan-Woo;Jang, Se-Young;Park, Eun-Ji;Yeo, Soo-Hwan;Jeong, Yong-Jin
    • Korean Journal of Food Science and Technology
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    • v.44 no.2
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    • pp.207-215
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    • 2012
  • Six different mashing types ((A) $koji$+purified enzyme, (B) $koji$+crude enzyme, (C) $koji$+$nuruk$, (D) $koji$+purified enzyme+$nuruk$, (E) $koji$+crude enzyme+$nuruk$, (F) purified enzyme+$nuruk$) had been established, according to fermentation agents and a mixing rate of rice $makgeolli$, in this study. The alcohol content was the highest in the mashing type (C), which was 13.6%, followed by (D) 13.5%, (A) 13.1%, (B) 12.9%, (E) 12.7% and (F) 12.1%. The reducing sugar content of (A) was the highest with 401.6 mg% and those of (B), (C), (D) and (F) were between 337.3- 380.9 mg%. The alcohol components were found and tended to increase during the fermentation. The oligo-saccharides content was the highest in (D) with 1251.3 mg%, which was followed by (E) 1,219.2 mg%, (C) 1,141.4 mg%, (A) 1,049.9 mg% and 973.8 mg% in (B). The total free amino acid was highest in (B) with 781.4 mg% and followed by (C) 703.2 mg%, (D) 702.6 mg%, (E) 678.7 mg%, (A) 630.4 mg% and (F) 328.7 mg% in order. There were 16 different types of volatile flavor components, in the mashing types (A) and (B), in addition to 15 different types of those in type (C), as well as 14 different types of those in (D), (E) and (F). There were significant differences in the overall preference between the type (A) and (C).

Effect of Annealing Temperature on Superconducting Properties of Charcoal Doped $MgB_2$ (목탄이 첨가된 $MgB_2$의 초전도 성질에 미치는 열처리 온도의 영향)

  • Kim, Nam-Kyu;Tana, Kai Sin;Jun, Byung-Hyuk;Park, Hai-Woong;Joo, Jin-Ho;Kim, Chan-Joong
    • Progress in Superconductivity
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    • v.9 no.1
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    • pp.80-84
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    • 2007
  • Charcoal was used as a carbon source for improving the critical current density of $MgB_2$ and the effect of annealing temperature on the $J_c$ of $MgB_2$ was investigated. The charcoal powder used in this study was $1{\sim}2$ microns in size and was prepared by wet attrition milling. $MgB_2$ bulk samples with a nominal composition of $Mg(B_{0.95}C_{0.05})_2$ were prepared by in situ process of Mg and B powders. The powder mixture was uniaxially compacted into pellets and heat treated at temperatures of $650^{\circ}C\;-\;1000^{\circ}C$ for 30 minutes in flowing Ar gas. It was found that superconducting transition temperature of $Mg(B_{0.95}C_{0.05})_2$ decreased by charcoal additions which indicates the carbon substitution for boron site. $J_c$ of $Mg(B_{0.95}C_{0.05})_2$ was lower than that of the undoped $MgB_2$ at the magnetic fields smaller than 4 Tesla, while it was higher than that of the undoped sample especially at the magnetic field higher than 4 T. High temperature annealing seems to be effective in increasing $J_c$ due to the enhanced carbon diffusion into boron sites.

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Effect of boron milling on phase formation and critical current density of MgB2 bulk superconductors

  • Kang, M.O.;Joo, J.;Jun, B.H.;Park, S.D.;Kim, C.S.;Kim, C.J.
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.1
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    • pp.18-24
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    • 2019
  • This study was carried out to investigate the effect of milling of boron (B), which is one of raw materials of $MgB_2$, on the critical current density ($J_c$) of $MgB_2$. B powder used in this study is semi-amorphous B (Pavezyum, Turkey, 97% purity, 1 micron). The size of B powder was reduced by planetary milling using $ZrO_2$ balls (a diameter of 2 mm). The B powder and balls with a ratio of 1:20 were charged in a ceramic jar and then the jar was filled with toluene. The milling time was varied from 0 to 8 h. The milled B powders were mixed with Mg powder in the composition of (Mg+2B), and the powder mixtures were uniaxially pressed at 3 tons. The powder compacts were heat-treated at $700^{\circ}C$ for 1 h in flowing argon gas. Powder X-ray diffraction and FWHM (Full width at half maximum) were used to analyze the phase formation and crystallinity of $MgB_2$. The superconducting transition temperature ($T_c$) and $J_c$ of $MgB_2$ were measured using a magnetic property measurement system (MPMS). It was found that $B_2O_3$ was formed by B milling and the subsequent drying process, and the volume fraction of $B_2O_3$ increased as milling time increased. The $T_c$ of $MgB_2$ decreased with increasing milling time, which was explained in terms of the decreased volume fraction of $MgB_2$, the line broadening of $MgB_2$ peaks and the formation of $B_2O_3$. The $J_c$ at 5 K increased with increasing milling time. The $J_c$ increase is more remarkable at the magnetic field higher than 3 T. The $J_c$ at 5 K and 4 T was the highest as $4.37{\times}10^4A/cm^2$ when milling time was 2 h. The $J_c$ at 20 K also increased with increasing milling time. However, The $J_c$ of the samples with the prolonged milling for 6 and 8 h were lower than that of the non-milled sample.