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Characteristics of Unrecorded Yeasts, Rhodosporidium fluviale, Rhodosporidium paludigenum, Candida sp. 80-J-3 and Kluyveromyces thermotolerans Isolated from Wild Flowers in Korea (국내 야생화들로부터 국내 미기록 효모, Rhodosporidium fluviale, Rhodosporidium paludigenum과 Candida sp. 80-J-3, Kluyveromyces thermotolerans의 특성)

  • Hyun, Se-Hee;Lee, Hyang Burm;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.41 no.3
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    • pp.181-184
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    • 2013
  • Rhodosporidium fluviale 201-C-1 and Kluyveromyces thermotolerans 150-JE-2(1) were isolated from wild flowers in Geumsan-gun, Chungcheongnam-do and Wando-gun, Jeollanam-do, respectively. Rhodosporidium paludigenum 86-J-1 and Candida sp. 80-J-3 were also isolated from flowers in Jeju island, Korea. Characteristics for these yeasts were not reported before. Therefore, morphological and physiological characteristics for these yeasts were investigated in this study. R. fluviale 201-C-1 was halophilic asporogenous yeast and formed pseudomycelium. It also grew at $30^{\circ}C$ and pH 4.0-6.0. K. thermotolerans 150-JE-2(1) was sugar-tolerant and halotolerant asporogenous yeast. It formed pseudomycelium and showed positive urease activity. Candida sp. 80-J-3 and R. paludigenum 86-J-1 were asporogenous yeasts, and grew well in yeast extract-peptone dextrose(YPD) medium, potato-dextrose medium as well as vitamin-free medium and YPD medium containing 5% NaCl.

CONTROLLABILITY OF NONLINEAR DELAY PARABOLIC EQUATIONS UNDER BOUNDARY CONTROL

  • Park, Jong-Yeoul;Kwun, Young-Chel;Jeong, Jin-Mun
    • Journal of the Korean Mathematical Society
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    • v.33 no.2
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    • pp.333-346
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    • 1996
  • Let $A(\zeta, \partial)$ be a second order uniformly elliptic operator $$ A(\zeta, \partial )u = -\sum_{j, k = 1}^{n} \frac{\partial\zeta_i}{\partial}(a_{jk}(\zeta)\frac{\partial\zeta_k}{\partial u}) + \sum_{j = 1}^{n}b_j(\zeta)\frac{\partial\zeta_j}{\partial u} + c(\zeta)u $$ with real, smooth coefficients $a_{j, k}, b_j$, c defined on $\zeta \in \Omega, \Omega$ a bounded domain in $R^n$ with a sufficiently smooth boundary $\Gamma$.

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ON A NEW CLASS OF INTEGRALS INVOLVING GENERALIZED HYPERGEOMETRIC FUNCTION 3F2

  • Kim, Insuk;Shantha Kumari., K.;Vyas, Yashoverdhan
    • Honam Mathematical Journal
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    • v.40 no.1
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    • pp.61-73
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    • 2018
  • The main aim of this research paper is to evaluate the general integral of the form $${\int_{0}^{1}}x^{c-1}(1-x)^{c+{\ell}}[1+{\alpha}x+{\beta}(1-x)]^{-2c-{\ell}-1}\atop {\times}_3F_2\left\[ {a,\;b,\;2c+{\ell}+1} \\ {\frac{1}{2}(a+b+i+1),\;2c+j\;;\frac{(1+{\alpha})x}{1+{\alpha}x+{\beta}(1-x)} }\right]dx$$ in the most general form for any ${\ell}{\in}\mathbb{Z}$; and $i, j=0,{\pm}1,{\pm}2$. The results are established with the help of generalized Watson's summation theorem due to Lavoie, et al. Fifty interesting general integrals have also been obtained as special cases of our main findings.

Heat Inactivation of Proteolytic Enzymes in Papaya Latex (Papaya Latex에 있는 단백질분해효소(蛋白質分解酪素)들의 열불활성(熱不活性)에 관하여)

  • Noh, Bong-Soo;Park, Kwan-Hwa
    • Korean Journal of Food Science and Technology
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    • v.12 no.3
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    • pp.209-215
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    • 1980
  • Proteases from papaya latex were partially purified by ammonium sulfate precipitation and separated into two fractions (Fraction I and II ) by carboxymethyl cellelose column chromatography. Each fraction, mixture of the two fractions, and crude extract of the papaya latex at pH 7.0 were inactivated at the range of $60{\sim}90^{\circ}C$ and thermal properties of the enzymes were investigated. In the thermal inactivation of fraction I, the enthalpy of activation was 89.5 kJ/mol; the entropy of activation, -44.0 J/mol K; the free energy of activation, 104.6 kJ/mol; z-value, $25^{\circ}C$. For fraction II, the enthalpy of activation was 96.5 kJ,/mol; the entropy of activation, -22.0 J/mol K; the free energy of activation, 104.0 kJ/mol; z-value, $23^{\circ}C$. For the mixture of fraction I and II, the enthalpy of activation was 90.9 kJ/mol; the entropy of activation, -38.8 J/mol·K; the free energy of activation, 104.2 kJ/mol; z-value, $24.6^{\circ}C$. For crude extract, the enthalpy of activation was 113.8 kJ/mol; the entropy of activation, 22.0 J/mol·K; the free energy of activation, 106.2 kJ/mol; z-value, $23.2^{\circ}C$. It was indicated that the fraction I was more heat-stable than the fraction II and this suggested that the thermal stability of the proteases in papaya latex is probably due to the fraction I.

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Synthesis and Properties of 1,4-Diboracyclohexene-2 Derivatives (1,4-Dibora-2-cyclohexene 유도체들의 합성과 그 성질)

  • Uhm, Jae-Kook;Hu D.;Zenneek U.;Pritzkow H.;Siebert W.
    • Journal of the Korean Chemical Society
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    • v.34 no.5
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    • pp.490-497
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    • 1990
  • Two synthetic routes for the 1,4-diboracyclohexene-2 ring 8 have been developed. Method i) starts with 1,2-bis(dichloroaluminyl)ethane, in which the AlCl$_2$ group is replaced by BCl$_2$. Exchange of the chlorine with BI$_3$ in 1,2-bis-(dichloroboryl)ethane yields the corresponding iodo compound, which reacts with the alkynes to heterocycles 8a, b in good yield. In method ii) B$_2$Cl$_4$ is added to alkenes, replacement of chlorine with BI$_3$ yields the bis(diiodoboryl)ethane derivatives which undergo redox reactions with alkynes to give 8c, d. The diiodo derivative 8a forms the pyridine adduct 9a, and reacts with ether to give the ethoxy derivative 8f. 8a-d react with AlMe$_3$ to yield the corresponding dimethyl derivatives 8g-j, which give unstable radical anions when treated with potassium in THF. The ESR parameters are reported. In electrochemical experiments irreversible reductions of 8g-j are observed. 8g-j react with (C$_5$H$_5$)Co(C$_2$H$_4$)$_2$ to give the intermediate 16 VE complexes (C$_5$H$_5$)Co(8), in which C-H activation occurs with formation of the corresponding red 1,4-diboracyclohexadiene complexes 10. The X-ray structure analyses of 10h and 10j are reported.

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Thermo-physiological Responses of the Lower Grade Elementary School Children -A Comparison Between Japanese and Korean Children- (초등학교 저학년 아동의 체온조절반응 -일본아동과 한국아동의 비교-)

  • Kim Seong-Hee;Lee Uk-Ja;Tamura Teruko
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.12 s.148
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    • pp.1527-1534
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    • 2005
  • In order to clarify the characteristics of the thermo-physiological responses of the child and to understand the influence of the country where the child has grown up on the responses, the thermo-physiological responses of the Japanese children(J group) and the Korean children(K group) were examined. The subject wearing shorts was exposed first to a thermo neutral room$(Ta=28.5^{\circ}C)$ for 1 hour, then transferred to a cold$(Ta=22^{\circ}C)$ or a hot$(Ta=37^{\circ}C)$ room for 1 hour. The experiment was done in the climate chamber of Bunka Women's University in the summer of 1997 for Japan, and in the climate chamber in the Keimyung University in the summer of 1998 for Korea. The subjects consisted of 5 boys and 5 girls aged 7-9 years in Japan and 4 boys and 4 girls aged 7-9 years in Korea. As a result: 1) The rectal temperature increased slightly with a rise in air temperature. K group showed a slightly higher rectal temperature. 2) The skin temperature of the hand and foot decreased conspicuously during cold exposure. It was more in the K group than in the J group. 3) Relative local sweat rates were similar in the two groups at $22^{\circ}C\;and\;28.5^{\circ}C$, while they were considerably different at $37^{\circ}C$. Even perspiration was observed over the whole body in the J group but the perspiration was large in the trunk and low in the extremity in the K group. 4) The heart rate was higher in the J group than in the K group but it increased with the rise of the air temperature in both groups.

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.

Thermal Inactivation of Lipase from Geotrichum candidum (Geotrichum candidum Lipase의 열불활성(熱不活性)에 관(關)하여)

  • Park, K.H.
    • Applied Biological Chemistry
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    • v.20 no.1
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    • pp.101-104
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    • 1977
  • Lipase from Geotrichum candidum was heat inactivated in 0.1M phosphate buffer solution. The thermal inactivation followed first order kinetics for the range of temperatures $50^{\circ}-80^{\circ}C$ except at $50^{\circ}C$. The changes in enthalpy, entropy and Gibbs free energy at $60^{\circ}C$ were 120.4 kJ/mol, 73.0 J/mol K and 96.9 kJ/mol respectively a value of $19^{\circ}C$(Geotrichum candidum lipase) is greater than that of lipases from milk and pancreas. The effect of detergents, lecithin and linoleic acid or the thermal inactivation of lipase was found to be negligible.

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CHARACTERIZATIONS OF THE EXPONENTIAL DISTRIBUTION BY ORDER STATISTICS AND CONDITIONAL

  • Lee, Min-Young;Chang, Se-Kyung;Jung, Kap-Hun
    • Communications of the Korean Mathematical Society
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    • v.17 no.3
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    • pp.535-540
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    • 2002
  • Let X$_1$, X$_2$‥‥,X$\_$n/ be n independent and identically distributed random variables with continuous cumulative distribution function F(x). Let us rearrange the X's in the increasing order X$\_$1:n/ $\leq$ X$\_$2:n/ $\leq$ ‥‥ $\leq$ X$\_$n:n/. We call X$\_$k:n/ the k-th order statistic. Then X$\_$n:n/ - X$\_$n-1:n/ and X$\_$n-1:n/ are independent if and only if f(x) = 1-e(equation omitted) with some c > 0. And X$\_$j/ is an upper record value of this sequence lf X$\_$j/ > max(X$_1$, X$_2$,¨¨ ,X$\_$j-1/). We define u(n) = min(j|j > u(n-1),X$\_$j/ > X$\_$u(n-1)/, n $\geq$ 2) with u(1) = 1. Then F(x) = 1 - e(equation omitted), x > 0 if and only if E[X$\_$u(n+3)/ - X$\_$u(n)/ | X$\_$u(m)/ = y] = 3c, or E[X$\_$u(n+4)/ - X$\_$u(n)/|X$\_$u(m)/ = y] = 4c, n m+1.