2,563 research outputs found

    Observations of copolar correlation coefficient through a bright band at vertical incidence

    Get PDF
    Includes bibliographical references (page 52).This paper discusses an application of polarimetric measurements at vertical incidence. In particular, the correlation coefficients between linear copolar components are examined, and measurements obtained with the NSSL's and NCAR's polarimetric radars are presented. The data are from two well-defined bright bands. A sharp decrease of the correlation coefficient, confined to a height interval of a few hundred meters, marks the arttom of the bright band

    Growth Stress Induced Tunability of Dielectric Constant in Thin Films

    Full text link
    It is demonstrated here that growth stress has a substantial effect on the dielectric constant of zirconia thin films. The correct combination of parameters - phase, texture and stress - is shown to yield films with high dielectric constant and best reported equivalent oxide thickness of 0.8 nm. The stress effect on dielectric constant is twofold, firstly, by the effect on phase transitions and secondly by the effect on interatomic distances. We discuss and explain the physical mechanisms involved in the interplay between the stress, phase changes and the dielectric constant in detail.Comment: 11 pages, 5 figure

    Inverse beta decay reaction in 232^{232}Th and 233^{233}U fission antineutrino flux

    Full text link
    Energy spectra of antineutrinos coming from 232^{232}Th and 233^{233}U neutron-induced fission are calculated, relevant inverse beta decay νeˉ+pn+e+\bar{{\nu}_e}+p \to n + e^{+} positron spectra and total cross sections are found. This study is stimulated by a hypothesis that a self-sustained nuclear chain reaction is burning at the center of the Earth ("Georeactor"). The Georeactor, according to the author of this idea, provides energy necessary to sustain the Earth's magnetic field. The Georeactor's nuclear fuel is 235^{235}U and, probably, 232^{232}Th and 233^{233}U. Results of present study may appear to be useful in future experiments aimed to test the Georector hypothesis and to estimate its fuel components as a part of developments in geophysics and astrophysics based on observations of low energy antineutrinos in Nature.Comment: 6 pages in LaTeX and 2 ps figures. Submitted to Physics of Atomic Nucle

    Examining Granular Computing from a Modeling Perspective

    Get PDF
    In this paper, we use a set of unified components to conduct granular modeling for problem solving paradigms in several fields of computing. Each identified component may represent a potential research direction in the field of granular computing. A granular computing model for information analysis is proposed. The model may suggest that granular computing is an instrument for implementing perception based computing based on numeric computing. In addition, a novel granular language modeling technique is proposed for information extraction from web pages. This paper also suggests that the study of data mining in the framework of granular computing may address the issues of interpretability and usage of discovered patterns

    Biomedical Relationship Extraction from Literature Based on Bio-Semantic Token Subsequences

    Get PDF
    Relationship Extraction (RE) from biomedical literature is an important and challenging problem in both text mining and bioinformatics. Although various approaches have been proposed to extract protein?protein interaction types, their accuracy rates leave a large room for further exploring. In this paper, two supervised learning algorithms based on newly defined bio-semantic token subsequence are proposed for multi-class biomedical relationship classification. The first approach calculates a bio-semantic token subsequence kernel , whereas the second one explicitly extracts weighted features from bio-semantic token subsequences. The two proposed approaches outperform several alternatives reported in literature on multi-class protein?protein interaction classification

    On the Mass Eigenstate Composition of the 8B Neutrinos from the Sun

    Get PDF
    The present data of gallium experiments provide indirectly the only experimental limit on the fraction of ν2\nu_2 mass eigenstate for the 8^8B neutrinos from the Sun. However, if to use the experimental data alone, the fraction of ν2\nu_2 and, consequently, sin2θsolsin^2\theta_{sol} still is allowed to be varied within a rather broad range. The further experimental efforts are needed to clear this point.Comment: 13 pages, 1 figure, 1 table. Corrected version, published in JCAP04(2007)00

    Quantum versus Semiclassical Description of Selftrapping: Anharmonic Effects

    Full text link
    Selftrapping has been traditionally studied on the assumption that quasiparticles interact with harmonic phonons and that this interaction is linear in the displacement of the phonon. To complement recent semiclassical studies of anharmonicity and nonlinearity in this context, we present below a fully quantum mechanical analysis of a two-site system, where the oscillator is described by a tunably anharmonic potential, with a square well with infinite walls and the harmonic potential as its extreme limits, and wherein the interaction is nonlinear in the oscillator displacement. We find that even highly anharmonic polarons behave similar to their harmonic counterparts in that selftrapping is preserved for long times in the limit of strong coupling, and that the polaronic tunneling time scale depends exponentially on the polaron binding energy. Further, in agreement, with earlier results related to harmonic polarons, the semiclassical approximation agrees with the full quantum result in the massive oscillator limit of small oscillator frequency and strong quasiparticle-oscillator coupling.Comment: 10 pages, 6 figures, to appear in Phys. Rev.

    Unique Factorization For Tensor Products of Parabolic Verma Modules

    Full text link
    Let g\mathfrak{g} be a symmetrizable Kac-Moody Lie algebra with Cartan subalgebra h\mathfrak{h}. We prove a unique factorization property for tensor products of parabolic Verma modules. More generally, we prove unique factorization for products of characters of parabolic Verma modules when restricted to certain subalgebras of h\mathfrak{h}. These include fixed point subalgebras of h\mathfrak{h} under subgroups of diagram automorphisms of g\mathfrak{g} and twisted graph automorphisms in the affine case.Comment: 20 page

    Development of a Beneficiation Flow Sheet for Processing Silica Sand from Chertala Area of kerala

    Get PDF
    The silica sand from Chertala area of Alappuzha district has been reported to be of good quality. Presently, it is mined and transported to destinations inside and outside the State without any processing. A project on beneficiat-ion/ value addition of this sand was taken up as per the request from Directorate of Industries and Commerce, Govt. of Kerala. Objective of the project is to develop a flow sheet for the total utilization of all fractions of this sand. The aim is to value add the same to produce special grade glass making sand according to BIS specifications (IS:488-1980), a suitable fraction for foundry application as per 1S:3018- 1977 and also to recover the finer fractions of sand and heavy minerals which are below 180,um and consti-tutes about 14% by weight. However, only the first two objectives are covered in the present work
    corecore