12,550 research outputs found

    Thermionic research and development program Final report, 15 Jul. 1966 - 15 Jan. 1968

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    Thermionic research and development program - improvement of performance of low emitter temperature cesium vapor thermionic converter

    Restoring Health to Health Reform: Integrating Medicine and Public Health to Advance the Population\u27s Wellbeing

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    The Patient Protection and Affordable Care Act is a major achievement in improving access to health care services. However, evidence indicates that the nation could achieve greater improvements in health outcomes, at a lower cost, by shifting its focus to public health. By focusing nearly exclusively on health care, policy makers have chronically starved public health of adequate and stable funding and political support. The lack of support for public health is exacerbated by the fact that health care and public health are generally conceptualized, organized, and funded as two separate systems. In order to maximize gains in health status and to spend scarce health resources most effectively, health care and public health should be treated as two interactive parts of a single, unified health system. The core purpose of health reform ought to be the improvement of the population’s health. We propose five criteria that would significantly advance this goal: prevention and wellness, human resources, a strong and sustainable health infrastructure, robust performance measurement, and reduction of health disparities. Although the Patient Protection and Affordable Care Act includes provisions addressing these criteria, population health is not a central focus of the reform. In order to guide health reform implementation and to inform future health reform efforts, we offer three major policy reforms: changing the environment to incentivize healthy behavioral choices, strengthening the public health infrastructure at the state and local levels, and developing a health-in-all policies strategy that would engage multiple agencies in improving health incomes. Adopting these reforms would facilitate integration and dramatically improve the population’s health, particularly when compared to the health gains likely to be realized from a continued focus on access to health care services

    On the effects of the Dvali-Gabadadze-Porrati braneworld gravity on the orbital motion of a test particle

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    In this paper we explicitly work out the secular perturbations induced on all the Keplerian orbital elements of a test body to order O(e^2) in the eccentricity e by the weak-field long-range modifications of the usual Newton-Einstein gravity due to the Dvali-Gabadadze-Porrati (DGP) braneworld model. The Gauss perturbative scheme is used. It turns out that the argument of pericentre and the mean anomaly are affected by secular rates which are independent of the semimajor axis of the orbit of the test particle. The first nonvaishing eccentricity-dependent corrections are of order O(e^2). For circular orbits the Lue-Starkman (LS) effect on the pericentre is obtained. Some observational consequences are discussed for the Solar System planetary mean longitudes lambda which would undergo a 1.2\cdot 10^-3 arcseconds per century braneworld secular precession. According to recent data analysis over 92 years for the EPM2004 ephemerides, the 1-sigma formal accuracy in determining the Martian mean longitude amounts to 3\cdot 10^-3 milliarcseconds, while the braneworld effect over the same time span would be 1.159 milliarcseconds. The major limiting factor is the 2.6\cdot 10^-3 arcseconds per century systematic error due to the mismodelling in the Keplerian mean motion of Mars. A suitable linear combination of the mean longitudes of Mars and Venus may overcome this problem. The formal, 1-sigma obtainable observational accuracy would be \sim 7%. The systematic error due to the present-day uncertainties in the solar quadrupole mass moment, the Keplerian mean motions, the general relativistic Schwarzschild field and the asteroid ring would amount to some tens of percent.Comment: LaTex2e, 23 pages, 5 tables, 1 figure, 37 references. Second-order corrections in eccentricity explicitly added. Typos corrected. References update

    s-Processing in the Galactic Disk. I. Super-Solar Abundances of Y, Zr, La, Ce in Young Open Clusters

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    In a recent study, based on homogeneous barium abundance measurements in open clusters, a trend of increasing [Ba/Fe] ratios for decreasing cluster age was reported. We present here further abundance determinations, relative to four other elements hav- ing important s-process contributions, with the aim of investigating whether the growth found for [Ba/Fe] is or not indicative of a general property, shared also by the other heavy elements formed by slow neutron captures. In particular, we derived abundances for yttrium, zirconium, lanthanum and cerium, using equivalent widths measurements and the MOOG code. Our sample includes 19 open clusters of different ages, for which the spectra were obtained at the ESO VLT telescope, using the UVES spectrometer. The growth previously suggested for Ba is confirmed for all the elements analyzed in our study. This fact implies significant changes in our views of the Galactic chemical evolution for elements beyond iron. Our results necessarily require that very low-mass AGB stars (M < 1.5M\odot) produce larger amounts of s-process elements (hence acti- vate the 13 C-neutron source more effectively) than previously expected. Their role in producing neutron-rich elements in the Galactic disk has been so far underestimated and their evolution and neutron-capture nucleosynthesis should now be reconsidered.Comment: ApJ accepte

    Administrators\u27 Perceptions of School-Based Management

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    The findings of this study suggest that the compatibility between the vision and reality of SBM in small rural districts make these sites ideal candidates for further analysis of the dynamics of increased school site autonomy

    “The Open SUNY Metaliteracy Badging System: Envisioning Connections with E-Portfolios.”

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    In a webinar presented for the Open Badges in Higher Education Working Group, librarians Trudi Jacobson and Kelsey O\u27Brien discuss the development of the Metaliteracy Badging System, a multi-media interactive tool used in conjunction with instructional sessions to teach information literacy and metaliteracy competencies. The presenters discuss their use of the system with disciplinary faculty and envision the potential for incorporating e-portfolios to showcase student achievements. *The audio file of this presentation is available here: https://archive.org/details/BAHigherEdWG8December2015. Please note that there are other presenters later in the webinar so you will need to secure their permission to upload the file to Scholars Archive

    Resonance NLS Solitons as Black Holes in Madelung Fluid

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    A new resonance version of NLS equation is found and embedded to the reaction-diffusion system, equivalent to the anti-de Sitter valued Heisenberg model, realizing a particular gauge fixing condition of the Jackiw-Teitelboim gravity. The space-time points where dispersion change the sign correspond to the event horizon, and the soliton solutions to the AdS black holes. The soliton with velocity bounded above describes evolution on the hyperboloid with nontrivial winding number and create under collisions the resonance states with a specific life time.Comment: Plain Tex, 12 pages, 6 figure

    Ionospheric Power-Spectrum Tomography in Radio Interferometry

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    A tomographic method is described to quantify the three-dimensional power-spectrum of the ionospheric electron-density fluctuations based on radio-interferometric observations by a two-dimensional planar array. The method is valid to first-order Born approximation and might be applicable to correct observed visibilities for phase variations due to the imprint of the full three-dimensional ionosphere. It is shown that not the ionospheric electron density distribution is the primary structure to model in interferometry, but its autocorrelation function or equivalent its power-spectrum. An exact mathematical expression is derived that provides the three dimensional power-spectrum of the ionospheric electron-density fluctuations directly from a rescaled scattered intensity field and an incident intensity field convolved with a complex unit phasor that depends on the w-term and is defined on the full sky pupil plane. In the limit of a small field of view, the method reduces to the single phase screen approximation. Tomographic self-calibration can become important in high-dynamic range observations at low radio frequencies with wide-field antenna interferometers, because a three-dimensional ionosphere causes a spatially varying convolution of the sky, whereas a single phase screen results in a spatially invariant convolution. A thick ionosphere can therefore not be approximated by a single phase screen without introducing errors in the calibration process. By applying a Radon projection and the Fourier projection-slice theorem, it is shown that the phase-screen approach in three dimensions is identical to the tomographic method. Finally we suggest that residual speckle can cause a diffuse intensity halo around sources, due to uncorrectable ionospheric phase fluctuations in the short integrations, which could pose a fundamental limit on the dynamic range in long-integration images.Comment: 8 pages; Accepted for publication in Ap
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