26,637 research outputs found

    Metropolitan Contexts for Community Initiatives: Contrasts in a Turbulent Decade

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    Analyzes demographic, social, and poverty data and 2000-10 changes in the economies and housing markets of fourteen metropolitan areas to inform Casey's strategies for reinvesting in initiatives including rehabilitation and minimizing vacancies

    Phase transition from hadronic matter to quark matter

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    We study the phase transition from nuclear matter to quark matter within the SU(3) quark mean field model and NJL model. The SU(3) quark mean field model is used to give the equation of state for nuclear matter, while the equation of state for color superconducting quark matter is calculated within the NJL model. It is found that at low temperature, the phase transition from nuclear to color superconducting quark matter will take place when the density is of order 2.5ρ0\rho_0 - 5ρ0\rho_0. At zero density, the quark phase will appear when the temperature is larger than about 148 MeV. The phase transition from nuclear matter to quark matter is always first order, whereas the transition between color superconducting quark matter and normal quark matter is second order.Comment: 18 pages, 11 figure

    Remotely Engaged? A Framework for Monitoring the Success of Stakeholder Engagement in Remote Regions

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    The importance of stakeholder engagement for the success of natural resources management processes is widely acknowledged, yet evaluation frameworks employed by administrators of environmental programs continue to provide limited recognition of or insistence upon engagement processes. This paper presents a framework for monitoring and evaluation of engagement that aims to better incorporate community engagement into mainstream environmental programs, in particular in remote regions such as arid and desert regions of the world. We argue that successful monitoring of engagement should not only comprise a generic set of indicators but rather, in addition to the principles of good monitoring practice, should take into account a variety of the stakeholder interests as well as key regional drivers, addressing them at right geographic, institutional and time scale.engagement, evaluation, governance, natural resources, participation, stakeholders

    The aspherical Cavicchioli-Hegenbarth-Repovš generalized Fibonacci groups

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    The Cavicchioli–Hegenbarth–Repovš generalized Fibonacci groups are defined by the presentations Gn (m, k) = 〈x 1, … , xn | xixi+m = xi+k (1 ⩽ i ⩽ n)〉. These cyclically presented groups generalize Conway's Fibonacci groups and the Sieradski groups. Building on a theorem of Bardakov and Vesnin we classify the aspherical presentations Gn (m, k). We determine when Gn (m, k) has infinite abelianization and provide sufficient conditions for Gn (m, k) to be perfect. We conjecture that these are also necessary conditions. Combined with our asphericity theorem, a proof of this conjecture would imply a classification of the finite Cavicchioli–Hegenbarth–Repovš groups

    Scale-free networks in complex systems

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    In the past few years, several studies have explored the topology of interactions in different complex systems. Areas of investigation span from biology to engineering, physics and the social sciences. Although having different microscopic dynamics, the results demonstrate that most systems under consideration tend to self-organize into structures that share common features. In particular, the networks of interaction are characterized by a power law distribution, P(k)kαP(k)\sim k^{-\alpha}, in the number of connections per node, kk, over several orders of magnitude. Networks that fulfill this propriety of scale-invariance are referred to as ``scale-free''. In the present work we explore the implication of scale-free topologies in the antiferromagnetic (AF) Ising model and in a stochastic model of opinion formation. In the first case we show that the implicit disorder and frustration lead to a spin-glass phase transition not observed for the AF Ising model on standard lattices. We further illustrate that the opinion formation model produces a coherent, turbulent-like dynamics for a certain range of parameters. The influence, of random or targeted exclusion of nodes is studied.Comment: 9 pages, 4 figures. Proceeding to "SPIE International Symposium Microelectronics, MEMS, and Nanotechnology", 11-15 December 2005, Brisbane, Australi

    In-medium electron-nucleon scattering

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    In-medium nucleon electromagnetic form factors are calculated in the quark meson coupling model. The form factors are typically found to be suppressed as the density increases. For example, at normal nuclear density and Q20.3GeV2Q^2 \sim 0.3 { GeV}^2, the nucleon electric form factors are reduced by approximately 8% while the magnetic form factors are reduced by only 1 - 2%. These variations are consistent with current experimental limits but should be tested by more precise experiments in the near future.Comment: 14 pages, latex, 3 figure

    Improving LLR Tests of Gravitational Theory

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    Accurate analysis of precision ranges to the Moon has provided several tests of gravitational theory including the Equivalence Principle, geodetic precession, parameterized post-Newtonian (PPN) parameters γ\gamma and β\beta, and the constancy of the gravitational constant {\it G}. Since the beginning of the experiment in 1969, the uncertainties of these tests have decreased considerably as data accuracies have improved and data time span has lengthened. We are exploring the modeling improvements necessary to proceed from cm to mm range accuracies enabled by the new Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) currently under development in New Mexico. This facility will be able to make a significant contribution to the solar system tests of fundamental and gravitational physics. In particular, the Weak and Strong Equivalence Principle tests would have a sensitivity approaching 1014^{-14}, yielding sensitivity for the SEP violation parameter η\eta of 3×105\sim 3\times 10^{-5}, v2/c2v^2/c^2 general relativistic effects would be tested to better than 0.1%, and measurements of the relative change in the gravitational constant, G˙/G\dot{G}/G, would be 0.1\sim0.1% the inverse age of the universe. Having this expected accuracy in mind, we discusses the current techniques, methods and existing physical models used to process the LLR data. We also identify the challenges for modeling and data analysis that the LLR community faces today in order to take full advantage of the new APOLLO ranging station.Comment: 15 pages, 3 figures, talk presented at 2003 NASA/JPL Workshop on Fundamental Physics in Space, April 14-16, 2003, Oxnard, C
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