9,996 research outputs found

    A Bibliometric Analysis of the Top 100 Cited Articles on Hepatic Magnetic Resonance Imaging.

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    The purpose of this study is to guide the readers to the impact of the articles published on hepatic magnetic resonance imaging (MRI). We searched Scopus using 10 different search terms for hepatic MRI. The selected studies were thoroughly reviewed by two independent authors and any disagreement was sorted out by mutual consensus. The list of articles and journals was downloaded into an excel spreadsheet. Only the top 100 cited articles were selected by mutual consensus among all the authors. These articles were further read in the full-text form and were further categorized into subgroups. Three authors independently reviewed the top 100 selected articles, and subsequently data was extracted from them and analyzed. Our study showed that the highest number of top 100 cited articles on hepatic MRI were from Radiology (30 articles) followed by European Radiology (14 articles). The American Journal of Roentgenology, Radiographics, and Journal of Magnetic Resonance had seven articles each. The United States had the highest number of articles by region. Nineteen other journals contributed only one article each to the list of top 100 cited articles. The contribution of authors to the top 100 cited articles was reviewed; all the authors contributing with more than two articles to the highly cited articles are given in Table 3 in the supplementary material. The maximum number of articles were published during 2009 (14 articles), and for a five-year period, the maximum contribution was made during 2008-2013 (44 articles). Our analysis gives an insight on the frequency of citations of top articles on hepatic MRI, categorizes the subtopics, the timeline of the publications, and contributions from different geographic distributions

    Higgs Inflation, Quantum Smearing and the Tensor to Scalar Ratio

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    In cosmic inflation driven by a scalar gauge singlet field with a tree level Higgs potential, the scalar to tensor ratio r is estimated to be larger than 0.036, provided the scalar spectral index n_s >= 0.96. We discuss quantum smearing of these predictions arising from the inflaton couplings to other particles such as GUT scalars, and show that these corrections can significantly decrease r. However, for n_s >= 0.96, we obtain r >= 0.02 which can be tested by the Planck satellite.Comment: 10 pages, 3 figures and 3 table

    Dirac versus Reduced Quantization of the Poincar\'{e} Symmetry in Scalar Electrodynamics

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    The generators of the Poincar\'{e} symmetry of scalar electrodynamics are quantized in the functional Schr\"{o}dinger representation. We show that the factor ordering which corresponds to (minimal) Dirac quantization preserves the Poincar\'{e} algebra, but (minimal) reduced quantization does not. In the latter, there is a van Hove anomaly in the boost-boost commutator, which we evaluate explicitly to lowest order in a heat kernel expansion using zeta function regularization. We illuminate the crucial role played by the gauge orbit volume element in the analysis. Our results demonstrate that preservation of extra symmetries at the quantum level is sometimes a useful criterion to select between inequivalent, but nevertheless self-consistent, quantization schemes.Comment: 24 page

    RF MEMS Based Tunable Bowtie Shaped Substrate Integrated Waveguide Filter

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    A tunable bandpass filter based on a technique that utilizes substrate integrated waveguide (SIW) and double coupling is presented. The SIW based bandpass filter is implemented using a bowtie shaped resonator structure. The bowtie shaped filter exhibits similar performance as found in rectangular and circular shaped SIW based bandpass filters. This concept reduces the circuit foot print of SIW; along with miniaturization high quality factor is maintained by the structure. The design methodology for single-pole triangular resonator structure is presented. Two different inter-resonator couplings of the resonators are incorporated in the design of the two-pole bowtie shaped SIW bandpass filter, and switching between the two couplings using a packaged RF MEMS switch delivers the tunable filter. A tunning of 1 GHz is achieved for two frequency states of 6.3 and 7.3 GHz. The total size of the circuit is 70mm x 36mm x 0.787 mm (LxWxH)

    Supersymmetric And Smooth Hybrid Inflation In The Light Of WMAP3

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    In their minimal form both supersymmetric and smooth hybrid inflation yield a scalar spectral index n_s close to 0.98, to be contrasted with the result n_s=0.951+0.015-0.019 from WMAP3. To realize better agreement, following hep-ph/0604198, we extend the parameter space of these models by employing a non-minimal Kaehler potential. We also discuss non-thermal leptogenesis by inflaton decay and obtain new bounds in these models on the reheat temperature to explain the observed baryon asymmetry.Comment: 21 pages, 12 figures, revtex4. v2: minor revisions, additional references, to appear in PR

    Determination of gamma-ray widths in 15^{15}N using nuclear resonance fluorescence

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    The stable nucleus 15^{15}N is the mirror of 15^{15}O, the bottleneck in the hydrogen burning CNO cycle. Most of the 15^{15}N level widths below the proton emission threshold are known from just one nuclear resonance fluorescence (NRF) measurement, with limited precision in some cases. A recent experiment with the AGATA demonstrator array determined level lifetimes using the Doppler Shift Attenuation Method (DSAM) in 15^{15}O. As a reference and for testing the method, level lifetimes in 15^{15}N have also been determined in the same experiment. The latest compilation of 15^{15}N level properties dates back to 1991. The limited precision in some cases in the compilation calls for a new measurement in order to enable a comparison to the AGATA demonstrator data. The widths of several 15^{15}N levels have been studied with the NRF method. The solid nitrogen compounds enriched in 15^{15}N have been irradiated with bremsstrahlung. The γ\gamma-rays following the deexcitation of the excited nuclear levels were detected with four HPGe detectors. Integrated photon-scattering cross sections of ten levels below the proton emission threshold have been measured. Partial gamma-ray widths of ground-state transitions were deduced and compared to the literature. The photon scattering cross sections of two levels above the proton emission threshold, but still below other particle emission energies have also been measured, and proton resonance strengths and proton widths were deduced. Gamma and proton widths consistent with the literature values were obtained, but with greatly improved precision.Comment: Final published version, minor grammar changes, 10 pages, 4 figures, 8 tables; An addendum is published where the last section is revised: T. Sz\"ucs and P. Mohr, Phys. Rev. C 92, 044328 (2015) [arXiv:1510.04956

    Encyclopedia of Bondage: Re-accentuation of the Past of Slavery in Morrison’s Beloved

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    The works of Toni Morrison to a great extent mirror the history of Afro-Americans. As a main figure of the Afro-American Renaissance, Miss Morrison makes Re-accentuation of slavery from past into present. She has made use of fiction writing as a method for remaking the past of slavery in American society. The basic thought implanted in the narrative of fiction by Morrisonis the position of black community in the white American community in the present era as well as in the past. Her writing is totally dedicated and given to black peopleand is a steady attempt to place things in the correct way and setting for them.Morrison's Beloved (1987) manages past as a storyline of the ownership of the most tangible reality of human presence as well as the most intellectual of human connections.It spotlights the dialogic inclinations of memory of the past of slavery and its inventive ability to construct and reconstruct the implication of past of slavery
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