419 research outputs found

    Computer mapping of LANDSAT data for environmental applications

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    The author has identified the following significant results. Land cover overlays and maps produced from LANDSAT are providing information on existing land use and resources throughout the 208 study area. The overlays are being used to delineate drainage areas of a predominant land cover type. Information on cover type is also being combined with other pertinent data to develop estimates of sediment and nutrients flows from the drainage area. The LANDSAT inventory of present land cover together with population projects is providing a basis for developing maps of anticipated land use patterns required to evaluate impact on water quality which may result from these patterns. Overlays of forest types were useful for defining wildlife habitat and vegetational resources in the region. LANDSAT data and computer assisted interpretation was found to be a rapid cost effective procedure for inventorying land cover on a regional basis. The entire 208 inventory which include acquisition of ground truth, LANDSAT tapes, computer processing, and production of overlays and coded tapes was completed within a period of 2 months at a cost of about 0.6 cents per acre, a significant improvement in time and cost over conventional photointerpretation and mapping techniques

    New vector-scalar contributions to neutrinoless double beta decay and constraints on R-parity violation

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    We show that in minimal supersymmetric standard model (MSSM) with R-parity breaking as well as in the left-right symmetric model, there are new observable contributions to neutrinoless double beta decay arising from hitherto overlooked diagrams involving the exchange of one W boson and one scalar boson. In particular, in the case of MSSM, the present experimental bounds on neutrinoless double beta decay lifetime improves the limits on certain R-parity violating couplings by about two orders of magnitude. It is shown that similar diagrams also lead to enhanced rates for μ−→e+\mu^-\rightarrow e^+ conversion in nuclei, which are in the range accessible to ongoing experiments.Comment: Latex file; 9 pages; 3 figures available on reques

    A Single Scale Theory for Cold and Hot Dark Matter

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    We show that a recently proposed extension of the MSSM can provide a scenario where both the cold and hot dark matter of the universe owe their origin to a single scale connected with the breakdown of the global B-L symmetry. The susy partner of the majoron and the light Majorana neutrinos are the cold and hot dark matter candidates respectively in this model and their desired relative abundances emerge when the scale of B-L symmetry breaking is in the TeV range.Comment: UMD-PP-94-102 (latex file; 15 pages

    Three-dimensional coherent X-ray diffraction imaging of a ceramic nanofoam: determination of structural deformation mechanisms

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    Ultra-low density polymers, metals, and ceramic nanofoams are valued for their high strength-to-weight ratio, high surface area and insulating properties ascribed to their structural geometry. We obtain the labrynthine internal structure of a tantalum oxide nanofoam by X-ray diffractive imaging. Finite element analysis from the structure reveals mechanical properties consistent with bulk samples and with a diffusion limited cluster aggregation model, while excess mass on the nodes discounts the dangling fragments hypothesis of percolation theory.Comment: 8 pages, 5 figures, 30 reference

    The Red Giant Branch Tip and Bump of the Leo II dwarf spheroidal galaxy

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    We present V and I photometry of a 9.4' X 9.4' field centered on the dwarf spheroidal galaxy Leo II. The Tip of the Red Giant Branch is identified at I^{TRGB}=17.83 +/- 0.03 and adopting = -1.53 +/- 0.2 from the comparison of RGB stars with Galactic templates, we obtain a distance modulus (m-M)_0=21.84 +/- 0.13, corresponding to a distance D=233 +/- 15 Kpc. Two significant bumps have been detected in the Luminosity Function of the Red Giant Branch. The fainter bump (B1, at V=21.76 +/- 0.05) is the RGB bump of the dominant stellar population, while the actual nature of the brightest one (B2, at V=21.35 +/- 0.05) cannot be firmly assessed on the basis of the available data, it can be due to the Asymptotic Giant Branch Clump of the main population or it may be a secondary RGB bump. The luminosity of the main RGB bump (B1) suggests that the majority of RGB stars in Leo II belongs to a population that is ~4 gyr younger than the classical Galactic globular clusters. The stars belonging to the He-burning Red Clump are shown to be significantly more centrally concentrated than RR Lyrae and Blue Horizontal Branch stars, probing the existence of an age/metallicity radial gradient in this remote dwarf spheroidal.Comment: Accepted for publication by MNRAS. Latex, 10 pages, 8 .ps figure

    Neutrinoless Double Beta Decay in Supersymmetric Seesaw model

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    Inspired by the recent HEIDELBERG-MOSCOW double beta decay experiment, we discuss the neutrinoless double beta decay in the supersymmetric seesaw model. Our numerical analysis indicates that we can naturally explain the data of the observed neutrinoless double beta decay, as well as that of the solar and atmospheric neutrino experiments with at least one Majorana-like sneutrino of middle energy scale in the model.Comment: latex, 25 pages, include 5 figures, final version in Phys. Rev.

    Not Managing Expectations: A Grounded Theory of Intimate Partner Violence From the Perspective of Pakistani People

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    Intimate partner violence (IPV) is a major social and public health problem affecting people from different cultures and societies. Much research has been undertaken to understand the phenomenon, its determinants, and its consequences in numerous countries. However, there is a paucity of research on IPV in many areas of the world including Pakistan. The present study aimed to develop a theory of the meaning and process of IPV from the perspective of Pakistani men and women living in and outside Pakistan

    Serial killing and the postmodern self

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    © 2006 by SAGE PublicationsThe self has been a consistently central theme in philosophy and the social sciences and, in the last decades of the 20th century, the fragmentation of the modern self has engendered extensive academic commentary. In order to contribute to current discussions about self, it is perhaps most effective to map the transformation of a single representation of the self in contemporary culture. As a cultural ‘flashpoint’, the serial killer could provide an apposite analytical focus. Drawing critically on Mark Seltzer's work on serial killers this article interprets serial killing as a form of commodified transgression. In contrast to the modern self, established through state-institutionalized routines, serial killers establish their identities through ecstatic intercourse. These acts of bodily and ethical transgression are facilitated by the use of commodities. In this way, the serial killer represents a self which is consistent with the colonization of interpersonal relations by multinational capital. The serial killer signifies the appearance of a postmodern self

    Quantum flutter of supersonic particles in one-dimensional quantum liquids

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    The non-equilibrium dynamics of strongly correlated many-body systems exhibits some of the most puzzling phenomena and challenging problems in condensed matter physics. Here we report on essentially exact results on the time evolution of an impurity injected at a finite velocity into a one-dimensional quantum liquid. We provide the first quantitative study of the formation of the correlation hole around a particle in a strongly coupled many-body quantum system, and find that the resulting correlated state does not come to a complete stop but reaches a steady state which propagates at a finite velocity. We also uncover a novel physical phenomenon when the impurity is injected at supersonic velocities: the correlation hole undergoes long-lived coherent oscillations around the impurity, an effect we call quantum flutter. We provide a detailed understanding and an intuitive physical picture of these intriguing discoveries, and propose an experimental setup where this physics can be realized and probed directly.Comment: 13 pages, 9 figure

    Multilingualism and the Brexit referendum

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    This chapter argues that the (lack of) foreign language skills has contributed to the outcome of the Brexit referendum. Theory suggests that speaking foreign languages reduces perceptions of cultural distance and contributes to the formation of transnational identities. Research also shows a link between language skills and European identity (Kuhn 2015; Díez Medrano 2018). Did Britons’ relative lack of foreign language skills play a role in the Brexit decision? Using matching methods and data from the referendum wave of the British Election Study, it is possible to estimate the effect of foreign language skills on the referendum vote. The results suggest that a significant effect of foreign language skills remains, even when taking into account education, age, gender, income, and region, party preference, and personality differences
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