• Title/Summary/Keyword: H143

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ABOUT THE PERIOD OF BELL NUMBERS MODULO A PRIME

  • Car, Mireille;Gallardo, Luis H.;Rahavandrainy, Olivier;Vaserstein, Leonid N.
    • Bulletin of the Korean Mathematical Society
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    • v.45 no.1
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    • pp.143-155
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    • 2008
  • Let p be a prime number. It is known that the order o(r) of a root r of the irreducible polynomial $x^p-x-l$ over $\mathbb{F}_p$ divides $g(p)=\frac{p^p-1}{p-1}$. Samuel Wagstaff recently conjectured that o(r) = g(p) for any prime p. The main object of the paper is to give some subsets S of {1,...,g(p)} that do not contain o(r).

The Experimental Study of Jeondo-san on Antioxidant Effects (전도산(顚倒散)의 항산화 효과에 관한 실험적 연구)

  • Choi, Kwan-Ho;Seo, Hyeong-Sik
    • Journal of Pharmacopuncture
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    • v.11 no.1
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    • pp.143-147
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    • 2008
  • Objectives : This study was carried out to investigate the antioxidant effects of Jeondo-san(JDS). Methods : The antioxidant effects of JDS were measured by the scavenging for 2,2-Diphenyl-1-picrylhydrazyl(DPPH) radical, the formation of intracellular glutathione(GSH), the inhibition for reactive oxygen species(ROS). Results : 1. All concentrations of JDS showed antioxidant effect by decreasing the DPPH radicals. 2. All concentrations of JDS did not effect on the formation of intracellular GSH in HaCaT cell. 3. All Concentrations of JDS inhibited the production of ROS in the HaCaT cell stimulated with $H_2O_2$. Conclusion : The present date suggest that JDS has effects on the stage of inflammation.

Equilibrium modeling for adsorption of NO3- from aqueous solution on activated carbon produced from pomegranate peel

  • Rouabeh, I.;Amrani, M.
    • Advances in environmental research
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    • v.1 no.2
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    • pp.143-151
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    • 2012
  • Nitrate removal from aqueous solution was investigated using $ZnCl_2$ and phosphoric acid activated carbon developed from pomegranate peel with particle size 0.4 mm. Potassium nitrate solution was used in batch adsorption experiments for nitrate removal from water. The effects of activated carbon dosage, time of contact, and pH were studied. The equilibrium time was fond to be 45 min. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir fit the isotherm with the theoretical adsorption capacity ($q_t$) was fond 78.125 mg g-1. Adsorption kinetics data were modeled using the pseudo-first, pseudo-second order, and intraparticle diffusion models. The results indicate that the second-order model best describes adsorption kinetic data. Results show activated carbon produced from pomegranate is effective for removal of nitrate from aqueous solution.

Electrical Properties and Clamping Voltage Characteristics of ZPCCY-Based Varistor Ceramics (ZPCCY계 바리스터 세라믹스의 전기적 성질 및 제한전압 특성)

  • Nahm Choon-Woo;Park Jong-Ah
    • Korean Journal of Materials Research
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    • v.15 no.3
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    • pp.143-148
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    • 2005
  • The microstructure, electrical properties, and clamping voltage characteristics of $ZnO-Pr_6O_{11}-CoO-Cr_2O_3-Y_2O_3(ZPCCY)-based$ varistor ceramics sintered at $1350^{\circ}C$ were investigated as a function of sintering time from 1 to 3 h. With increasing sintering time, the average grain size and density increased in the range of $11.4\~16.0\;{\mu}m$ and $5.34\~5.54g/cm^3$, respectively, in accordance of increasing sintering time. The nonlinear exponent decreased in the range of $60\~26$ and the leakage current increased in the range of $1.3\~10.7\;{\mu}A$ with increasing sintering time. The clamping voltage ratio increased in the range $1.58\~1.65$ for ratio surge current of 10 A as the sintering time increased.

GLOBAL EXISTENCE FOR 3D NAVIER-STOKES EQUATIONS IN A THIN PERIODIC DOMAIN

  • Kwak, Min-Kyu;Kim, Nam-Kwon
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.15 no.2
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    • pp.143-150
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    • 2011
  • We consider the global existence of strong solutions of the 3D incompressible Navier-Stokes equations in a thin periodic domain. We present a simple proof that a strong solution exists globally in time when the initial velocity in $H^1$ and the forcing function in $L^p$(0,${\infty}$;$L^2$), $2{\leq}p{\leq}{\infty}$ satisfy certain condition. This condition is basically similar to that by Iftimie and Raugel[7], which covers larger and larger initial data and forcing functions as the thickness of the domain ${\epsilon}$ tends to zero.

The cAMP/Protein Kinase A Pathway and Virulence in Cryptococcus neoformans

  • Kronstad, James W.;Hu, Guang-Gan;Choi, Jae-Hyuk
    • Mycobiology
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    • v.39 no.3
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    • pp.143-150
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    • 2011
  • The basidiomycete fungus Cryptococcus neoformans is an important pathogen of immunocompromised people. The ability of the fungus to sense its environment is critical for proliferation and the generation of infectious propagules, as well as for adaptation to the mammalian host during infection. The conserved cAMP/protein kinase A pathway makes an important contribution to sensing, as demonstrated by the phenotypes of mutants with pathway defects. These phenotypes include loss of the ability to mate and to elaborate the key virulence factors capsule and melanin. This review summarizes recent work that reveals new targets of the pathway, new phenotypic consequences of signaling defects, and a more detailed understanding of connections with other aspects of cryptococcal biology including iron regulation, pH sensing, and stress.

Relationship between Conformational Preferences and Torsional Parameters in Molecular Mechanics (MM3) Calculations

  • 조수경;박규순
    • Bulletin of the Korean Chemical Society
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    • v.18 no.2
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    • pp.143-149
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    • 1997
  • We have investigated a relationship between conformational preferences of various substituents in monosubstituted cyclohexanes and pertinent torsional parameter values in molecular mechanics calculations. We have manipulated torsional parameters to supply a certain energy difference between gauche and anti conformers, and applied those parameters to monosubstituted cyclohexanes. After investigating 6 different substituents, namely Me, SiH3, F, Cl, Br, and I, MM3 calculations show that (1) the MM3 calculated A values with the current torsional parameters reproduce the available experimental values well, (2) the conformational energy difference between axial and equatorial conformations (the A value) correlates perfectly with the gauche/anti energy differences of the corresponding butane-like fragment (correlation coefficient=l.000), and (3) the A values are essentially twice as the gauche/anti energy differences (slopes=1.86-2.00). On the basis of our analysis, the A values as well as the gauche/anti energy differences are easily calibrated by an adjustment of the relevant torsional parameter. Thus, our technique for tuning the torsional parameters may be of great use in updating molecular mechanics results about conformational preferences whenever a further refinement is necessary.

Neutron Cross Section Evaluation on Pr-141, Nd-143, Nd-145, Sm-147 and Sm-149

  • Lee, Y. D.;J. H. Chang
    • Nuclear Engineering and Technology
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    • v.34 no.4
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    • pp.370-381
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    • 2002
  • The neutron induced nuclear data for Pr-141, Nd-143, Nd-145, Sm-147 and Sm-149 were calculated and evaluated from 10 keV to 20 MeV. The energy dependent optical model potential parameters were extracted based on the recent experimental data and applied up to 20 MeV. The s-wave strength function was calculated. Spherical optical model , statistical model in equilibrium energy, multistep direct and multistep compound model in pre-equilibrium energy and direct capture model were introduced in Empire calculation. The theoretically calculated cross sections were compared with the experimental data and the evaluated files. The model calculated total and capture cross sections were in good agreement with the reference experimental data. The capture cross sections in pre-equilibrium were enhanced in recent released Empire version. The evaluated cross section results were compiled to ENDF-6 format and will improve the ENDF/B-Vl.