995 research outputs found

    Effective Monopole Action at Finite Temperature in SU(2) Gluodynamics

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    Effective monopole action at finite temperature in SU(2) gluodynamics is studied on anisotropic lattices. Using an inverse Monte-Carlo method and the blockspin transformation for space directions, we determine 4-dimensional effective monopole action at finite temperature. We get an almost perfect action in the continuum limit under the assumption that the action is composed of two-point interactions alone. It depends on a physical scale bsb_s and the temperature TT. The temperature-dependence appears with respect to the spacelike monopole couplings in the deconfinement phase, whereas the timelike monopole couplings do not show any appreciable temperature-dependence. The dimensional reduction of the 4-dimensional SU(2) gluodynamics ((SU(2))4D_{4D}) at high temperature is the 3-dimensional Georgi-Glashow model ((GG)3D(GG)_{3D}). The latter is studied at the parameter region obtained from the dimensional red uction. We compare the effective instanton action of (GG)3D(GG)_{3D} with the timelike monopole action obtained from (SU(2))4D_{4D}. We find that both agree very well for T2.4TcT \ge 2.4T_c at large bb region. The dimensional reduction works well also for the effective action.Comment: 34 pages, 23 figure

    Modeling the current distribution in HTS tapes with transport current and applied magnetic field

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    A numerical model is developed for the current distribution in a high temperature superconducting (HTS) tape, (Bi,Pb)2Sr2 Ca2Cu3Ox-Ag, subjected to a combination of a transport current and an applied magnetic field. This analysis is based on a two-dimensional formulation of Maxwell's equations in terms of an integral equation for the current density J. The finite thickness of the conductor and an arbitrary voltage-current relation (e.g. n-power relation, magnetic field dependency) for the conductor are included in the model. Another important feature is that the model also covers an applied magnetic field in arbitrary directions and a rotating field perpendicular to the conductor, which is of great interest for analyzing the AC loss of HTS (transformer) coils or three-phase electric power cables. A comparison is made with transport current loss measurements on an HTS tape with an AC applied fiel

    The liquid Miscibility Gap and the Distribution of Silver Between Speiss and Metallic Lead in the Pb-Fe-As, Pb-Cu-As and Pb-Fe-Cu-As System at 1200℃

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    The liquid miscibility gap and the distribution of silver between speiss and metallic lead for the Pb-Fe-Cu-As quarternary system have been determined at 1200℃. The miscibility gap in the Pb-Fe-As system covered a wide composition range. Molten lead containing a small amount of arsenic equilibrated with the speiss which consisted of iron arsenide with a small quantity of dissolved lead. The miscibility gap in the Pb-Cu-As system was also determined. In this system, the solubility of lead in speiss had a minimum with increasing arsenic content. In the quarternary system, the region of immiscibility was found to be distributed between the above, two, ternary systems on a pseudoternary phase diagram and was dependent on the cu/Fe+Cu ratio in speiss. The arsenic content in molten lead increased sharply beyond a definite quantity of arsenic in speiss. The behaviour of the distribution ratio of silver, K_, defined as wt.% Ag in speiss/wt.% Ag in metallic lead was summarized as follows : (1) In the Pb-Fe-As system, the values for K_ were low when the arsenic content in speiss was below 40% ; but above this range, the values increased sharply. (2) In the Pb-Cu-As system, K_ was around 1.2 for all speiss compositions investigated. (3) In the Pb-Fe-Cu-As system, the value of K_ was distributed between those obtained for the two ternary systems. The distribution ratios of silver derived from practical data agreed well with present work. From these results, a pyrometallurgical process in which lead and precious metals are recovered as bullion and in which arsenic is fixed and discarded as iron arsenide speiss can be proposed

    POU3F2 (POU class 3 homeobox 2)

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    POU3F2, also known as BRN2, Oct7, and N-Oct3, is a member of the neural cell-specific class III POU domain transcription factors (Ryan and Rosenfeld, 1997). POU3F2-knockout causes the loss of specific neuronal lineages in the endocrine hypothalamus and the subsequent loss of the posterior pituitary gland (Nakai et al., 1995; Schonemann et al., 1995; Alvarez-Bolado et al., 1995). And also, transgenes of POU3F2 and some other few factors converted non-neural cells to neural cells in vitro (Ambasudhan et al., 2011; Lujan et al., 2012; Pang et al., 2011). These results indicate that POU3F2 is an indispensable transcription factor for neural differentiation and generation of normal nervous system, especially hypothalamus. There have been a few reports regarding the functions of POU3F2 in association with tumorigenesis. POU3F2 has been demonstrated to be an oncogene in malignant melanomas derived from the neuroectodermal cell lineage and to accelerate the growth of melanoma cells (Cook and Sturm, 2008). POU3F2 are also highly expressed in small cell lung cancers and closely associated with the cancer specific neural/neuroendocrine phenotype (Schreiber et al., 1992; Ishii et al., 2013; Sakaeda et al., 2013)

    Molecular cloning and heterologous expression of novel glucosyltransferases from tobacco cultured cells that have broad substrate specificity and are induced by salicylic acid and auxin.

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    The definitive version is available at www.blackwell-synergy.com.Scopoletin is one of the phytoalexins in tobacco. Cells of the T-13 cell line (Nicotiana tabacum L. Bright Yellow) accumulate a large amount of scopoletin, also known as 7-hydroxy-6-methoxycoumarin, as a glucoconjugate, scopolin, in vacuoles. We report here the molecular cloning of glucosyltransferases that can catalyze the glucosylation of many kinds of secondary metabolites including scopoletin. Two cDNAs encoding glucosyltransferase (NtGT1a and NtGT1b) were isolated from a cDNA library derived from the tobacco T-13 cell line by screening with heterologous cDNAs as a probe. The deduced amino-acid sequences of NtGT1a and NtGT1b exhibited 92% identity with each other, ≈ 20–50% identities with other reported glucosyltransferases. Heterologous expression of these genes in Escherichia coli showed that the recombinant enzymes had glucosylation activity against both flavonoids and coumarins. They also strongly reacted with 2-naphthol as a substrate. These recombinant enzymes can utilize UDP-glucose as the sugar donor, but they can also utilize UDP-xylose as a weak donor. RNA blot analysis showed that these genes are induced by salicylic acid and auxin, but the time course of the expression was different. This result is similar to the changes in scopoletin glucosylation activity in these tobacco cells after addition of these plant growth regulators. These results might suggest that one of the roles of the products of these genes is scopoletin glucosylation, in response to salicylic acid and/or auxin, together with the other glucosyltransferases in tobacco cells.ArticleEuropean Journal of Biochemistry. 268(14):4086-4094 (2001)journal articl

    Twist glass transition in regioregulated poly(3-alkylthiophenes)s

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    The molecular structure and dynamics of regioregulated poly(3-butylthiophene) (P3BT), poly(3-hexylthiophene)(P3HT), and poly(3-dodecylthiophene) (P3DDT) were investigated using Fourier transform infrared absorption (FTIR), solid state 13^{13}C nuclear magnetic resonance (NMR), and differential scanning calorimetry (DSC) measurements. In the DSC measurements, the endothermic peak was obtained around 340 K in P3BT, and assigned to enthalpy relaxation that originated from the glass transition of the thiophene ring twist in crystalline phase from results of FTIR, 13^{13}C cross-polarization and magic-angle spinning (CPMAS) NMR, 13^{13}C spin-lattice relaxation time measurements, and centerband-only detection of exchange (CODEX) measurements. We defined this transition as {\it twist-glass transition}, which is analogous to the plastic crystal - glassy crystal transition.Comment: 9 pages, 10 figures, 2 tables. Phys.Rev.B, in pres

    Progress and Trends in Artificial Silk Spinning: A Systematic Review

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    More than 400 million years of natural selection acting throughout the arthropoda has resulted in highly specialized and energetically efficient processes to produce protein-based fibers with properties that are a source of inspiration for all. As a result, for over 80 years researchers have been inspired by natural silk production in their attempts to spin artificial silks. While significant progress has been made, with fibers now regularly outperforming silkworm silks, surpassing the properties of superior silks, such as spider dragline, is still an area of considerable effort. This review provides an overview of the different approaches for artificial silk fiber spinning and compares all published fiber properties to date which has identified future trends and challenges on the road towards replicating high performance silks
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