• Title/Summary/Keyword: $MgB_4$

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Fermentation Process and Physiochemical Characteristics of Yakju(Korean cleared rice wine) with Addition of Ginseng Powder (인삼박을 첨가한 약주의 제조 및 이화학적 특성)

  • 이인선;양의주;정용진;서지형
    • Food Science and Preservation
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    • v.6 no.4
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    • pp.463-468
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    • 1999
  • The characteristics and quality of Yakju with addition of ginseng powder originated in Choongchungdo were evaluated. At result, pH was decreased at the beginning stage of two stages fermentation and then slowly increased. Total acidity were increased in the cases of all (A), (B) and (C) during the fermentation. (A) group used Nuruk, crude enzyme and powder yeast showed the highest pH of 7.08 and total acidity of 0.84 at the 4th day of fermentation. The alcohol contents of B(21.0%) and C(20.4%) used cultured yeast were higher than A(19.0%) used powder yeast at the 4th day of fermentation. Also, inhibition against alcohol fermentation by ginseng powder wasn't showed and amino nitrogen contents were higher in (A) and (C) with addition of crude enzyme. Free sugar were the highest in (A) used both Nuruk and crude enzyme such as glucose of 599.16, maltose of 129.11mg%. Free amino acids were much more in A(580.02mg%) than in B(527.48mg%) and C(538.74mg%). from the sensory evaluation, desirable color and flavor qulity for 40 ages was (A) and (B) which was used Nuruk, and that for 20 ages was (C) which was used crude enzyme. However the best taste and overall preference was (B) for 20 and 40 ages of all. Therefore to produce high quality Yauju and commercialize, studies of fermentation process in Yakju should proceed later.

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Chemical Components of Gastrodia elata Blume Powder (천마 분말의 화학적 성분)

  • Kim, Hyeon-Ju;Chung, Shin-Kyo;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.7 no.3
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    • pp.278-284
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    • 2000
  • The chemical components in freeze dried Korean Gastrodia elata blume powder were analyzed. The proximate composition was composed of moisture(2.12%), crude protein (4.41%), crude fat(1.20%), crude ash(2.25%), crude fiber(4.60%) and N-free extract(85.15%). Free sugar was composed of glucose(1,314mg%), sucrose(1,081mg%) and fructose(869mg%). Total organic acid content was 2,095mg% and composed of succinic acid(1,238mg%), citric acid, malic acid, oxalic acid and fumaric acid in the order. Among the 11 fatty acids detected, linoleic acid was the most predominant one and unsaturated fatty acid was 80.55 area percent. 18 and 39 amino acids were detected from total and free amino acid, respectively. Arginine, asparagine, proline and sarcosine were the major components of free amino acid. The content of crude saponin and total phenol were 3,768mg% and 821mg%, respectively. Ascorbic acid(6.4mg%), vitamin B1(1.2mg%), vitamin B2(1.7mg%) and niacinamide(0.2m%) were detected as soluble vitamins of the powder. The content of vitamin A and vitamin E was 1.22mg% and 0.32%, respectively.

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A Study on the Composition of Seasoning Using Lentinus edodes. (표고버섯을 이용한 조미료의 주요성분에 관한 연구)

  • 차월석;이명렬;조배식;박세영
    • Journal of Life Science
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    • v.14 no.5
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    • pp.829-833
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    • 2004
  • The major compositions of Lentinus edodes seasoning(LES) compose of 30.3% of Lentinus edodes fruit body, 18.1 % of anchovy (Engraulis japonicus) powder and 51.6% of sea tangle (Laminaria japonica), prawn and green tea powder and so on were investigated in order to evaluate the nutritional value. Sodium concentration in LES was high up to 5,042.99 mg/IOO g and K, Ca, P, Mg, Fe, Zn, Mn and Cu were followed. There were nineteen total amino acids in LES. The glutamic acid content was high up to 4.62 mg/100 mg and glycine, leucine, alanine, aspartic acid were followed. Among twenty free amino acids, glycine content was high up to 2.37 mg/100 mg and glutamic acid, asparanine, proline, taurin and aspartic acid were followed. The contents of vitamin C in LES was high up to 224.78 mg/100 g and pantothenic acid, vitamin B$_{6}$, niacin, vitamin E, folic acid, vitamin B$_{l}$ vitamin B$_{2}$, vitamin D$_{3}$, vitamin A, vitamin B$_{12}$ and vitamin $K_{l}$ were followed.wed.

Superconducting properties of SiC-buffered-MgB2 tapes

  • Putri, W.B.K.;Kang, B.;Duong, P.V.;Kang, W.N.
    • Progress in Superconductivity and Cryogenics
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    • v.17 no.3
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    • pp.1-4
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    • 2015
  • Production of $MgB_2$ film on metallic Hastelloy with SiC as the buffer layer was achieved by means of hybrid physical-chemical vapor deposition technique, whereas SiC buffer layers with varied thickness of 170 and 250 nm were fabricated inside a pulsed laser deposition chamber. Superconducting transition temperature and critical current density were verified by transport and magnetic measurement, respectively. With SiC buffer layer, the reduced delaminated area at the interface of $MgB_2$-Hastelloy and the slightly increased $T_c$ of $MgB_2$ tapes were clearly noticed. It was found that the upper critical field, the irreversibility field and the critical current density were reduced when $MgB_2$ tapes were buffered with SiC buffer layer. Clarifying the mechanism of SiC buffer layer in $MgB_2$ tape in affecting the superconducting properties is considerably important for practical applications.

Influence of Ag nano-powder additions on the superconducting properties of Mg $B_2$ materials

  • K. J. Song;Park, S. J.;Kim, S. W.;Park, C.;J. H. Joo;Kim, H. J.;J. K. Chung;R. K. Ko;H. S. Ha
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.3
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    • pp.6-10
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    • 2003
  • Silver nano-powder was added to Ma $B_2$ to make (Ag)$_{(x)wt.%}$(Mg $B_2$)$_{(l00-x)wt.%}$ (A $g_{x}$-Mg $B_2$) (10 $\leq$ x $\leq$ 50) composite superconductors to investigate the effect of the Ag nano-powder on the vortex pinning. Pellets made out of the mixed powder were put inside stainless steel tubes, which were sintered at 85$0^{\circ}C$ in Ar atmosphere. No impurity phase was identified for as-rolled samples. However, both the Mg $B_2$ and the A $g_{x}$-Mg $B_2$ composite pellets, when sintered, contain small amount of Mg $B_4$ and MgAg impurity phases. From the magnetization study, it was found that the flux pinning was improved in the high magnetic field region (> 3 T) only when 10w/o Ag was added to Mg $B_2$. The "two step" structures in ZFC M(T) curve gradually increased as the amount of Ag added increased. Pinning centers can be created by adding a suitable amount of Ag nano-powder which is not too large to increase the decoupling between the Mg $B_2$ grains.crease the decoupling between the Mg $B_2$ grains.

Analysis of General Components and Vitamin and Mineral Contents of the Mushroom Agrocybe chaxingu (차신고버섯(Agrocybe chaxingu)의 일반성분, 비타민 및 미네랄 함량분석)

  • Lee, Kwang-Jae;Yun, In-Jue;Kim, Hee-Yeon;Park, Yu-Hwa;Ham, Hun-Ju;Park, Young-Hak;Joo, Jin-Ho;Lim, Sang-Hyun;Kim, Kyung-Hee
    • Food Science and Preservation
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    • v.16 no.4
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    • pp.549-553
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    • 2009
  • The mushroom Agrocybe chaxingu was analyzed to evaluate the nutritional value of this potential food. The moisture content was 88.9% in the fruiting body of A. chaxingu, and the proportions of ash, crude fiber, carbohydrate, crude protein, and crude fat were 0.9%, 1.4%, 7.2%, 2.5% and 0.4% by weight, respectively. A. chaxingu contained 1.29 mg/100 g edible weight of vitamin $B_1$, and the contents of vitamin $B_2$, vitamin $B_3$, and vitamin C were 0.15 mg, 0.32 mg, and 18.4 mg per 100 g of wet mushroom. Potassium (3,318 mg/100 g, dry basis) was found at the highest concentration in A. chaxingu. In addition, the mushroom contained many other minerals (all figures are mg per 100 g of dried mushroom) such as phosphorus (909.7), magnesium (141.3), sodium (12.7), zinc (7.4), iron (6.5), copper (2.8), manganese (0.8), and nickel (0.1). The results indicate that A. chaxingu is a valuable nutrient source.

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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Studies on Organic Acid, Vitamin and Free Sugar Contents of Commercial Dried Lavers (Porphyra yezoensis) Cultivated in Korea (시판 건조김의 유기산, 비타민 및 유리당 함량)

  • Park, Wook-Min;Kang, Dong-Soo;Bae, Tae-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.1
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    • pp.172-177
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    • 2014
  • The purpose of this study was to provide basic date for organic acid, vitamin and free sugar contents of commercial dried lavers cultivated in Korea (Seocheon, Wando, Goheung and Busan). The contents of organic acid per 100 g of dried lavers were in the range of 1,238.67~1,437.00 mg of malic acid, 1,021.67~1,309.67 mg of oxalic acid, 1,035.67~1,247.33 mg of citric acid, 1,001.00~1,146.00 mg of succinic acid, 902.00~1,107.00 mg of tartaric acid, 862.67~1,070.67 mg of lactic acid and 370.33~421.67 mg of acetic acid. The concentration of vitamin A and ${\beta}$-carotene were the highest (0.286 mg and 22.19 mg/100 g) in dried lavers cultivated from Seocheon and Wando. Vitamin $B_1$, $B_3$ and $B_{12}$ concentrations were the highest (9.79 mg, 19.15 mg and 1.77 mg/100 g) in dried lavers cultivated from Goheung, and vitamin $B_2$, $B_6$ and $B_9$ concentrations were the highest (4.55 mg, 2.36 mg and 2.17 mg/100 g) in dried lavers cultivated from Wando. The concentration of vitamin C and E contents were the highest (219.33 mg and 1.75 mg/100 g) in dried lavers cultivated from Wando. The contents of free sugar per 100 g of dried lavers were in the range of 214.27~347.72 mg of galactose, 59.10~71.69 mg of glucose, 37.86~54.34 mg of fucose and 6.26~14.65 mg of mannose.

Characteristics of Biological Phosphorus Removal in the MBR (MBR 공정에서의 인 제거 특성)

  • Choi, Hee-Jeong;Lee, Seung-Mok
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.2
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    • pp.197-204
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    • 2007
  • The reciprocal effects towards the enhanced biological phosphorus removal were performed for anaerobic, aerobic and anoxic phases. The batch experiments showed that the p-absorption in the anoxic phase was 50% lower than aerobic phase. The correlation coefficient between p-back-solution and p-absorption was found to be $R^2=0.557$ however, the coefficient b(b = 8.4049) was relatively higher than the other researchers results. The increase and/or acceptance of the $K^+-,\;Mg^{2+}-$ and $NH_4-N$-concentration was proportional to those of the $PO_4-P$-concentration in the batch test. The relationship between $K^+-,\;Mg^{2+}$ and $PO_4-P$ was determined. The average value of this relation-ship agreed with 0.2 mol $K^+Ion$ / mol $PO_4-P$ ion and 0.21 mol $Mg^{2+}Ion$ / moi $PO_4-P$ ion in the anaerobic phase. The absorbed ratio of $K^+$ to $Mg^{2+}$ over $PO_4-P$ was found to be 1 : 5.

Germanium-based pinning dopants for MgB2 bulk superconductors

  • Chung, K.C.;Ranot, M.;Shinde, K.P.;Oh, Y.S.;Kang, S.H.;Jang, S.H.;Hwang, D.Y.
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.2
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    • pp.36-39
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    • 2019
  • Effects of the spherically shaped Ge and the rod-like carbon-coated Ge on the superconducting properties of $MgB_2$ were investigated. Pure Ge and carbon-coated Ge nano-powders were synthesized under the different amount of $CH_4$ (0 to 5 kPa) by using DC thermal plasma method. When the $CH_4$ was added ~100 nm sized Ge with a spherical shape changed to rod-like morphology with a diameter of ~30-70 nm and a length of ~400-500 nm. Also it was confirmed that thin carbon layers of a few nanometers were formed along the rod length and the agglomerated carbons were found on the edges of rods. Pure spherical Ge and Ge/C rods were mixed and milled with Mg & B precursor to form the doped $MgB_2$ bulk samples by the solid-state reaction method. Almost no change of $T_c$ was noticed for the pure Ge-added $MgB_2$, whereas $T_c$ was found to decrease with the Ge/C-added $MgB_2$ samples. It was found that the pure spherical Ge showed to have a negative effect on the flux pinning of $MgB_2$. However, Ge/C rods can enhance the flux pinning property of $J_c$ due to the coated carbon on Ge rods.