50,250 research outputs found

    On the absence of Shapiro-like steps in certain mesoscopic S-N-S junctions

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    In DC transport through mesoscopic S-N-S junctions, it is known that the Josephson coupling decreases exponentially with increasing temperature, but the phase dependence of the conductance persists to much higher temperatures and decreases only as 1/T. It is pointed out here that, despite the fact that such a phase-dependent conductance does bring about an AC current for a pure DC voltage, it cannot, by itself, lead to the formation of Shapiro steps.Comment: 1 page, to be published in PRL (as Comment

    Letter from N. H. Harris to General W. S. Featherston. 26 January 1878

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    Letter sent from Vicksburg; regarding enclosed papers from General E. P. Alexander for use in preparation of narrative for Colonel Claiborne.https://egrove.olemiss.edu/ciwar_corresp/1274/thumbnail.jp

    Thermal and Non-thermal Plasmas in the Galaxy Cluster 3C 129

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    We describe new Chandra spectroscopy data of the cluster which harbors the prototypical "head tail" radio galaxy 3C 129 and the weaker radio galaxy 3C 129.1. We combined the Chandra data with Very Large Array (VLA) radio data taken at 0.33, 5, and 8 GHz (archival data) and 1.4 GHz (new data). We also obtained new HI observations at the Dominion Radio Astrophysical Observatory (DRAO) to measure the neutral Hydrogen column density in the direction of the cluster with arcminute angular resolution. The Chandra observation reveals extended X-ray emission from the radio galaxy 3C 129.1 with a total luminosity of 1.5E+41 erg/s. The X-ray excess is resolved into an extended central source of ~2 arcsec (1 kpc) diameter and several point sources with an individual luminosity up to 2.1E+40 erg/s. In the case of the radio galaxy 3C 129, the Chandra observation shows, in addition to core and jet X-ray emission reported in an earlier paper, some evidence for extended, diffuse X-ray emission from a region east of the radio core. The 12 arcsec x 36 arcsec (6 kpc x 17 kpc) region lies "in front" of the radio core, in the same direction into which the radio galaxy is moving. We use the radio and X-ray data to study in detail the pressure balance between the non-thermal radio plasma and the thermal Intra Cluster Medium (ICM) along the tail of 3C 129 which extends over 15 arcmin (427 kpc). Depending on the assumed lower energy cutoff of the electron energy spectrum, the minimum pressure of the radio plasma lies a factor of between 10 and 40 below the ICM pressure for a large part of the tail. We discuss several possibilities to explain the apparent pressure mismatch.Comment: Accepted for publication in MNRAS. Refereed manuscript. 14 pages, 8 figures, additional panel of Fig. 3 shows asymmetric ICM distributio

    Stable isotope studies on granulites from the high grade terrain of Southern India

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    Fluid inclusion and petrologic characteristics of South India granulites and their bearing on the sources of metamorphic fluids are discussed. This paper served as a review and an introduction to the next paper by D. Jackson. Jackson presented carbon isotope data from gases extracted from fluid inclusions in South Indian granulites. The uniformly low Delta C-13 values (minus 10 plus or minus 2 per mil) and the greater abundance of CO2 in the incipient charnockites are suggestive of fluid influx from an externally buffered reservoir

    Characteristics and carbon stable isotopes of fluids in the Southern Kerala granulites and their bearing on the source of CO2

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    Carbon dioxide-rich inclusions commonly occur in the banded charnockites and khondalites of southern Kerala as well as in the incipient charnockites formed by desiccation of gneisses along oriented zones. The combined high density fluid inclusion isochores and the range of thermometric estimates from mineral assemblages indicate entrapment pressures in the range of 5.4 to 6.1 Kbar. The CO2 equation of state barometry closely compares with the 5 plus or minus 1 Kbar estimate from mineral phases for the region. The isochores for the high density fluid inclusions in all the three rock types pass through the P-T domain recorded by phase equilibria, implying that carbon dioxide was the dominating ambient fluid species during peak metamorphic conditions. In order to constrain the source of fluids and to evaluate the mechanism of desiccation, researchers undertook detailed investigations of the carbon stable isotope composition of entrapped fluids. Researchers report here the results of preliminary studies in some of the classic localities in southern Kerala namely, Ponmudi, Kottavattom, Manali and Kadakamon

    On the Formation of Galaxy Halos: Comparing NGC 5128 and the Local Group Members

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    The metallicity distribution function (MDF) for the old red-giant stars in the halo of NGC 5128, the nearest giant elliptical galaxy, is virtually identical with the MDF for the old-disk stars in the LMC and also strongly resembles the halo MDF in M31. These galaxies all have high mean halo metallicities ( ~ -0.4$) with very small proportions of low-metallicity stars. These observations reinforce the view that metal-rich halos are quite normal for large galaxies of all types. Such systems are unlikely to have built up by accretion of pre-existing, gas-free small satellite galaxies, unless these satellites had an extremely shallow mass distribution (d log N / d log M > -1). We suggest that the halo of NGC 5128 is more likely to have assembled from hierarchical merging of gas-rich lumps in which the bulk of star formation took place during or after the merger stage.Comment: 10 pages, LaTeX, plus 3 figures in separate postscript files; Astronomical Journal, in press for December 200

    Perancangan Buku Panduan Wisata Karangpandan

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    Indonesia merupakan Negara yang kaya akan berbagai sumber daya alam. Keindahan alamnya pun luar biasa dan tidak semua Negara memiliki keindahan dan kekayaan alam seperti yang dimiliki oleh Negara ini. Begitu juga dengan pulau Jawa yang memiliki keindahan alam dan memiliki berbagai pesona daerah wisata. Daerah wisata Karangpandan merupakan daerah wisata di daerah Solo, Jawa Tengah yang sangat indah pesonanya. Sayangnya masyarakat lokal banyak yang tidak mengetahui tentang adanya daerah wisata ini. Oleh karena itu dibuatlah perancangan ini yang bertujuan untuk mengenalkan daerah wisata Karangpandan pada masyarakat yang tidak mengetahui daerah wisata Karangpandan tersebut

    Susceptibility of the 2D S=1/2 Heisenberg antiferromagnet with an impurity

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    We use a quantum Monte Carlo method (stochastic series expansion) to study the effects of a magnetic or nonmagnetic impurity on the magnetic susceptibility of the two-dimensional Heisenberg antiferromagnet. At low temperatures, we find a log-divergent contribution to the transverse susceptibility. We also introduce an effective few-spin model that can quantitatively capture the differences between magnetic and nonmagnetic impurities at high and intermediate temperatures.Comment: 5 pages, 4 figures, v2: Updated data in figures, minor changes in text, v3: Final version, cosmetic change

    Survival of near-critical branching Brownian motion

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    Consider a system of particles performing branching Brownian motion with negative drift μ=2ϵ\mu = \sqrt{2 - \epsilon} and killed upon hitting zero. Initially there is one particle at x>0x>0. Kesten showed that the process survives with positive probability if and only if ϵ>0\epsilon>0. Here we are interested in the asymptotics as \eps\to 0 of the survival probability Qμ(x)Q_\mu(x). It is proved that if L=π/ϵL= \pi/\sqrt{\epsilon} then for all xRx \in \R, limϵ0Qμ(L+x)=θ(x)(0,1)\lim_{\epsilon \to 0} Q_\mu(L+x) = \theta(x) \in (0,1) exists and is a travelling wave solution of the Fisher-KPP equation. Furthermore, we obtain sharp asymptotics of the survival probability when x<Lx<L and LxL-x \to \infty. The proofs rely on probabilistic methods developed by the authors in a previous work. This completes earlier work by Harris, Harris and Kyprianou and confirms predictions made by Derrida and Simon, which were obtained using nonrigorous PDE methods
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