14,200 research outputs found

    Defining the gap between research and practice in public relations programme evaluation - towards a new research agenda

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    The current situation in public relations programme evaluation is neatly summarized by McCoy who commented that 'probably the most common buzzwords in public relations in the last ten years have been evaluation and accountability' (McCoy 2005, 3). This paper examines the academic and practitioner-based literature and research on programme evaluation and it detects different priorities and approaches that may partly explain why the debate on acceptable and agreed evaluation methods continues. It analyses those differences and proposes a research agenda to bridge the gap and move the debate forward

    Bacterial Source Tracking to Support the Development and Implementation of Watershed Protection Plans for the Lampasas and Leon Rivers: Lampasas River Watershed Final Report

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    The Bacterial Source Tracking to Support the Development and Implementation of Watershed Protection Plans for the Lampasas and Leon Rivers project was developed to provide supplemental information to stakeholders engaged in the development and implementation of watershed protection plans for each watershed. The Leon River is listed as an impaired water body for elevated levels of E. coli and does not support its designated contact recreation use. The Lampasas River was also considered impaired for elevated E. coli levels until 2010 when it was determined that the data listing the segment no longer met the state’s criteria for assessment. Through the watershed protection planning process, stakeholders in each watershed will use adaptive management to refine management strategies that will mitigate bacteria loading from potential sources of pollution within the watershed

    Student understanding of rotational and rolling motion concepts

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    We investigated the common difficulties that students have with concepts related to rotational and rolling motion covered in the introductory physics courses. We compared the performance of calculus- and algebra-based introductory physics students with physics juniors who had learned rotational and rolling motion concepts in an intermediate level mechanics course. Interviews were conducted with six physics juniors and ten introductory students using demonstration-based tasks. We also administered free-response and multiple-choice questions to a large number of students enrolled in introductory physics courses, and interviewed six additional introductory students on the test questions (during the test design phase). All students showed similar difficulties regardless of their background, and higher mathematical sophistication did not seem to help acquire a deeper understanding. We found that some difficulties were due to related difficulties with linear motion, while others were tied specifically to the more intricate nature of rotational and rolling motion.Comment: 23 pages, 3 figures, 2 tables; it includes a multiple-choice test (in Appendix B

    The Phase Diagram of High Temperature QCD with Three Flavors of Improved Staggered Quarks

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    We report on progress in our study of high temperature QCD with three flavors of improved staggered quarks. Simulations are being carried out with three degenerate quarks with masses less than or equal to the strange quark mass, msm_s, and with degenerate up and down quarks with masses in the range 0.1ms≤mu,d≤0.6ms0.1 m_s \leq m_{u,d}\leq 0.6 m_s, and the strange quark mass fixed near its physical value. For the quark masses studied to date we find rapid crossovers, which sharpen as the quark mass is reduced, rather than bona fide phase transitions.Comment: Lattice 2003 (Nonzero temperature and density

    VLBA Continuum and H I Absorption Observations of the Ultra-Luminous Infrared Galaxy IRAS 17208-0014

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    We present phase-referenced VLBI observations of the radio continuum emission from, and the neutral hydrogen 21 cm absorption toward, the Ultra-Luminous Infrared Galaxy IRAS 17208-0014. The observations were carried out at 1362 MHz using the Very Long Baseline Array, including the phased Very Large Array as an element. The high-resolution radio continuum images reveal a nuclear starburst region in this galaxy, which is composed of diffuse emission approximately 670 x 340 pc on the plane of the sky, and a number of compact sources. These sources are most likely to be clustered supernova remnants and/or luminous radio supernovae. Their brightness temperatures range over (2.2-6.6) x 10^{5} K, with radio spectral luminosities between (1-10) x 10^{21} W Hz^{-1}. The total VLBI flux density of the starburst region is ~52 mJy, which is about 50% of the total flux density detected with the VLA at arcsecond resolution. For this galaxy, we derive a massive star formation rate of ~84pm13 M{_\odot} yr^{-1}, and a supernova rate of ~4pm1 yr^{-1}. H I absorption is detected in multiple components with optical depths ranging between 0.3 and 2.5, and velocity widths between 58 and 232 km s^{-1}. The derived column densities, assuming T_{s}=100 K, range over (10-26) x 10^{21} cm^{-2}. The H I absorption shows a strong velocity gradient of 453 km s^{-1} across 0.36 arcsec (274 pc). Assuming Keplerian motion, the enclosed dynamical mass is about 2.3 x 10^9 sin^{-2}i M{_\odot}, comparable to the enclosed dynamical mass estimated from CO observations.Comment: 26 pages total, 6 figures. ApJ accepted. To appear in the April 1, 2003 issue of ApJ. For a version with better images, see http://www.aoc.nrao.edu/~emomjian/IRAS.p

    Surprising Connections Between General Relativity and Condensed Matter

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    This brief review is intended to introduce gravitational physicists to recent developments in which general relativity is being used to describe certain aspects of condensed matter systems, e.g., superconductivity.Comment: 14 pages; based on talk given at GR1

    Inflating magnetically charged braneworlds

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    Numerical solutions of Einstein, scalar, and gauge field equations are found for static and inflating defects in a higher-dimensional spacetime. The defects have (3+1)(3+1)-dimensional core and magnetic monopole configuration in n=3n=3 extra dimensions. For symmetry-breaking scale η\eta below the critical value ηc\eta_c, the defects are characterized by a flat worldsheet geometry and asymptotically flat extra dimensions. The critical scale ηc\eta_c is comparable to the higher-dimensional Planck scale and has some dependence on the gauge and scalar couplings. For η=ηc\eta=\eta_c, the extra dimensions degenerate into a `cigar', and for η>ηc\eta>\eta_c all static solutions are singular. The singularity can be removed if the requirement of staticity is relaxed and defect cores are allowed to inflate. The inflating solutions have de Sitter worldsheets and cigar geometry in the extra dimensions. Exact analytic solutions describing the asymptotic behavior of these inflating monopoles are found and the parameter space of these solutions is analyzed.Comment: 35 pages, revtex, 18 eps figure

    Towards the Final Fate of an Unstable Black String

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    Black strings, one class of higher dimensional analogues of black holes, were shown to be unstable to long wavelength perturbations by Gregory and Laflamme in 1992, via a linear analysis. We revisit the problem through numerical solution of the full equations of motion, and focus on trying to determine the end-state of a perturbed, unstable black string. Our preliminary results show that such a spacetime tends towards a solution resembling a sequence of spherical black holes connected by thin black strings, at least at intermediate times. However, our code fails then, primarily due to large gradients that develop in metric functions, as the coordinate system we use is not well adapted to the nature of the unfolding solution. We are thus unable to determine how close the solution we see is to the final end-state, though we do observe rich dynamical behavior of the system in the intermediate stages.Comment: 17 pages, 7 figure

    Monte Carlo study of the Widom-Rowlinson fluid using cluster methods

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    The Widom-Rowlinson model of a fluid mixture is studied using a new cluster algorithm that is a generalization of the invaded cluster algorithm previously applied to Potts models. Our estimate of the critical exponents for the two-component fluid are consistent with the Ising universality class in two and three dimensions. We also present results for the three-component fluid.Comment: 13 pages RevTex and 2 Postscript figure
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