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IRAS OBSERVATIONS OF DARK GLOBULES

  • Lee, H.M.;Hong, S.S.;Kwon, S.M.
    • Journal of The Korean Astronomical Society
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    • v.24 no.1
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    • pp.55-70
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    • 1991
  • Infrared emission maps are constructed at 12.5, 25, 60, and $100{\mu}m$ for dark globules B5, B34, B133, B134, B361, L134 and L1523 by using Infrared Astronomical Satellite data base. These clouds are selected on the basis of their appearance in Palomar print as dark obscuring objects with angular sizes in the range of 3 to 30 arcminutes. The short wavelength(12.5 and $25{\mu}m$) maps show the embedded infrared sources. We found many such sources only in B5, B361 and B34 regions, Diffuse component at 12.5 and $25{\mu}m$, possibly arising from the stochastically heated very small dust grains(a < $0.01{\mu}m$) by interstellar radiation field, is found in B361 and L1523 regions. Such emission is characterized by the limb brightening, and it is confirmed in L1523 and in B361. Infrared emissions at the long wavelengths(60 and $100{\mu}m$) are due to colder dusts with temperature less than 20 K. The distribution of color index determined by the ratio 60 to $100{\mu}m$ intensities shows monotonic decrease of dust temperature toward the center. The black body temperature determined from these ratios is found to lie between 16 and 23 K. Such temperature is possible for small(i.e., $a\;{\lesssim}\;0.01{\mu}m$) graphite grains if the grains are mainly heated by interstellar radiation field. Thus IRAS 100 and $60{\mu}m$ emissions are arising mainly from small grains in the colud. The distribution of such dust grains implied from the emissivity distributions at 100 and $60{\mu}m$ resembles that of isothermal sphere. This contrasts to earlier findings of much steeper distribution of dusts contributing visible extinction. These dust grains are mainly larger ones(i.e., $a{\simeq}0.1{\mu}m$). Therefore we conclude that the average grain size increase, toward the cloud center.

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Modular Exponentiation by m-Numeral System (m-진법 모듈러 지수연산)

  • Lee, Sang-Un
    • The KIPS Transactions:PartC
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    • v.18C no.1
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    • pp.1-6
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    • 2011
  • The performance and practicality of cryptosystem for encryption, decryption, and primality test is primarily determined by the implementation efficiency of the modular exponentiation of $a^b$(mod n). To compute $a^b$(mod n), the standard binary squaring still seems to be the best choice. But, the d-ary, (d=2,3,4,5,6) method is more efficient in large b bits. This paper suggests m-numeral system modular exponentiation. This method can be apply to$b{\equiv}0$(mod m), $2{\leq}m{\leq}16$. And, also suggests the another method that is exit the algorithm in the case of the result is 1 or a.

MULTIPLIERS OF WEIGHTED BLOCH SPACES AND BESOV SPACES

  • Yang, Gye Tak;Choi, Ki Seong
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.727-737
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    • 2009
  • Let M(X) be the space of all pointwise multipliers of Banach space X. We will show that, for each $\alpha>1$, $M(\mathfrak{B}_\alpha)=M(\mathfrak{B}_{\alpha,0})=H^\infty{(B)}$. We will also show that, for each $0<{\alpha}<1$, $M(\mathfrak{B}_\alpha)$ and $M(\mathfrak{B}_{\alpha,0})$ are Banach algebras. It is established that certain inclusion relationships exist between the weighted Bloch spaces and holomorphic Besov spaces.

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A Case Study on the Application of T.B.M Tunnelling in Hard Rock (HARD ROCK에서의 T.B.M 공법 적용사례)

  • 박용운;박홍조
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.10b
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    • pp.103-118
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    • 1993
  • The application of T.B.M tunnelling has been progressively increased since the first entrance into Korea in 1985 and especially, its higher performance and safety is widely proved as a generalized tunnelling in hardrock tunnel construction, comparing wi th conventional method. This case announcement will be much helpful for your general understanding of T.B.M tunnelling and the development of tunneling technology by introducing the brief methods and construction results from the actual application cases of T.B.M tunnelling in Ulsan Water Supply Tunnel Project, the longest tunnel in Korea under construction by YOU ONE. Co.

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The Enhancement of Cytochrome P-450 Mediated Aryl Hydroxylation of Bentazon in Rice Microsomes (벼에서 Bentazon 히드록시화반응에 관련된 Cytochrome P-450 활성(活性) 증진(增進)에 관한 연구(硏究))

  • Pyon, J.Y.;Balke, N.E.
    • Korean Journal of Weed Science
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    • v.17 no.1
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    • pp.59-65
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    • 1997
  • Bentazon 6-hydroxylase (B6H) and cinnamic acid 4-hydroxylase (CA4H) activities were determined in rice (Oryza sativa L.) microsomes to study methods of enhancing cytochrome P-450 mediated aryl hydroxylation of bentazon by hydoxylase inducing compounds. Pretreating rice seeds with 1,8-naphthalic anhydride at 0.5-2% and fenclorim at 5 and 10 ${\mu}M$ increased B6H and CA4H activities. Treatments of rice seedling with ethanol 2.5% enhanced B6H and CA4H activities, and with phenobarbital at 12 mM enhanced B6H activity, and CA4H activity was enhanced at 2 mM. B6H activity was synergistically enhanced by combined treatments of ethanol 2.5 or 5% and phenobarbital 8 or 12mM and also that of 1,8-naphthalic anhydride 0.5 or 1% and phenobarbital 8 or 12 mM, but CA4H activity was decreased by combined treatment. Five-day-old rice seedlings showed higher B6H and CA4H activities which decreased with seedling age.

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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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A Study on the Variation of the Concentrations of Carbon Species and B(a)P Associated in Atmospheric Suspended Particles in an Urban Area of Seoul (서울지역 일부 대기중 부유먼지에 함유된 탄소 성분과 Benzo(a)pyrene 성분의 농도변동 양상에 관한 연구)

  • 황경철;김희강
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.91-96
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    • 1997
  • In order to investigate the behavior of particulate carbon and benzo(a)pyrene(B(a)P) in the ambient air, suspended particle matters were collected from April, 1990 to February, 1992, and total carbon(TC), organic carbon(OC), elemental carbon(EC) and B(a)P were measured by an elemental analyzer and a HPLC. The results were as follows the average concentration of TC was 38.6 $\mug/m^3$ and its concentration was higher in winter(45.4 $\mug/m^3$) and fa11(44.3 $\mug/m^3$) than in summer(36.8 $\mug/m^3$) and spring(28.9 $\mug/m^3$). The monthly concentration trends both of EC and OC was similar, but seasonal variation of EC concentrations was larger than that of OC. The average concentration of B (a)P was 2.2 ng/m$^3$, and was higher in winter(4.1 ng/m$^3$) and fall(3.2 ng/m$^3$) than in spring(1.2 ng/m$^3$) and summer(0.6 ng/m$^3$). The seasonal behavior of carbon and B(a)P was to similar except for summer. The correlation coefficient(r) between EC and B(a)P was 0.71, and the correlation coefficient(r) between OC and B(a)P was 0.66.

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The Effect of Vitamin B6 Deficiency on the Utilization of Fuel and Blood Cholesterol Profile with Regular Exercise-Training in Rats (비타민 B6 부족이 정기적인 운동 훈련시 연료의 이용과 혈액 콜레스테롤 성상에 미치는 영향)

  • 조윤옥
    • Journal of Nutrition and Health
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    • v.29 no.8
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    • pp.881-888
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    • 1996
  • The purpose of this study was to determine whether vitamin B6(B6) deficiency affects fuel utilization and blood cholesterol profile with exercise-training. Twenty-four rats were fed a B6 deficient(-B6) diet or a control (+B6) diet for 5 weeks and either exercised(EX) or nonexercised (NE). EX rats were exercised on treadmill(10$^{\circ}$, 0.5-0.8km/h) for 20 minutes everyday. Glucose(GLU), glycogen (GLY), protein(PRO), trglyceride(TG), free fatty acid(FFA), total cholesterl(TC), HDL-cholesterol(HDL-C) and LDL-choleterol(LDL-C) were compared in plasma(P), liver(L) and skeletal muscle(M) of rats. There was a vitamin effect on the level of P-GLU, P-TG, M-TG, L-GLY, L-PRO and an exercise effect on the level of P-PRO, P-FFA, M-PRO, L-GLY, L-TG, P-TC, P-HDL-C, P-LDL-C. Compared to +B6 rats were lower and there were no differences in P-GLU, P-FFA, P-TG. M-GLY, L-TG, P-TC and P-HDL-C. In EX group, the level of P-TG was higher and M-PRO was lower in -B6 rats. There were no differences in M-GLY, L-TG, P-TC and P-HDL-C. These results suggest that a lowered intake of vitamin B6 may impair the adaptation of animals to fuel metabolism related to a decrease of fatty acid oxidation and attenuates the exercise-traning effect on blood lipid profile.

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Purification of Xylogone sphaerospora ${\beta}$-mannanase and Growth Activity of Bifidobacterium spp. by Konjac Glucomannan Hydrolysates (Xylogone sphaerospora 유래 ${\beta}$-mannanase 정제 및 Konjac Glucomannan 가수분해 올리고당의 중합도별 Bifidobacterium spp.에 대한 증식활성)

  • Lee, Hee-Jung;Park, Gwi-Gun
    • Applied Biological Chemistry
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    • v.51 no.3
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    • pp.159-163
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    • 2008
  • Xylogone sphaerospora ${\beta}$-mannanase was purified by Sephadex G-100 column chromatography. The specific activity of the purified enzyme was 8.44 units/ml protein, representing an 56.27-folds purification of the original crude extract. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 42kDa. Konjac glucomannan was hydrolyzed by the purified ${\beta}$-mannanase, and then the hydrolysates was separated by activated carbon column chromatography. The main hydrolysates were composed of D.P. (Degree of Polymerization) 3 and 4 glucomannooligosaccharides. For elucidate the structure of D.P 3 and 4 glucomannooligosaccharides, sequential enzymatic action was performed. D.P 3 and 4 were identified as M-G-M and M-M-G-M (G- and M- represent glucosidic and mannosidic link-ages). To investigate the effects of konjac glucomannooligosaccharides on in vitro growth of Bifido-bacterium longum, B. bifidum, B. infantis, B. adolescentis, B. animalis, B. auglutum and B. breve. Bifidobacterium spp. were cultivated individually on the modified-MRS medium containing carbon source such as D.P. 3 and D.P. 4 glucomannooligosaccharides, respectively. B. longum and B. bifidum grew up 3.9-fold and 2.8-fold more effectively by the treatment of D.P. 4 glucomannooligosaccharides, compared to those of standard MRS medium. Especially, D.P. 4 was more effective than D.P. 3 glucomannooligosaccharide on the growth of Bifidobacterium spp.

Purification and Characterization of $\beta$-Xylosidase B of Bacillus stearothemophilus No.236 Produced by Recombinant Escherichia coli. (재조합 균주 Escherichia coli가 생산하는 Bacillus stearothermophilus No.236 $\beta$-Xylosidase B의 정제 및 특성)

  • 장욱진;조쌍구;최용진
    • Microbiology and Biotechnology Letters
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    • v.26 no.4
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    • pp.297-302
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    • 1998
  • $\beta$-Xylosidase B was produced by Escherichia coli HB101/pKMG12 carrying the xylB gene of Bacillus stearothermophilus No.236 on its recombinant plasmid. The $\beta$-xylosidase B produced was purified by ammonium sulfate fractionation, DEAE-Sepharose CL-6B, Sephacryl S-200 and Superdex 200 HR gel filtration. The purified enzyme showed the highest activity at pH 6.5 and 5$0^{\circ}C$. But, the enzyme was observed to be very sensitive to the pH and temperature of the reaction mixture. The enzyme was activated about 35% of its original activity in the presence of 1 mM of $Mn^{2+}$ but it was completely inhibited by $Ag^{+}$, $Cu^{2+}$and $Hg^{2+}$ions. In contrast with the $\beta$-xylosidase A, the B enzyme was found to have $\alpha$-arabinofuranosidase activity though the activity was fairly low compared with the $\alpha$-arabinofuranosidase produced from the arfI gene of the same Bacillus stearothermophilus. Therefore, $\beta$-xylosidase B is considered to be more suitable than $\beta$-xylosidase A at least for the biodegradation of arabinoxylan. The $K_{m}$ and V$_{max}$ values of the $\beta$-xylosidase B for o-nitrophenyl-$\alpha$-D-xylopyranoside were 6.43 mM and 1.45 $\mu$mole/min, respectively. Molecular mass of the enzyme was determind to be about 54 kDa by SDS-PAGE and 160 kDa by Superdex 200HR gel filtration, indicating that the functional $\beta$-xylosidase B was composed of three identical subunits.s.

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