8,171 research outputs found

    EACOF: A Framework for Providing Energy Transparency to enable Energy-Aware Software Development

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    Making energy consumption data accessible to software developers is an essential step towards energy efficient software engineering. The presence of various different, bespoke and incompatible, methods of instrumentation to obtain energy readings is currently limiting the widespread use of energy data in software development. This paper presents EACOF, a modular Energy-Aware Computing Framework that provides a layer of abstraction between sources of energy data and the applications that exploit them. EACOF replaces platform specific instrumentation through two APIs - one accepts input to the framework while the other provides access to application software. This allows developers to profile their code for energy consumption in an easy and portable manner using simple API calls. We outline the design of our framework and provide details of the API functionality. In a use case, where we investigate the impact of data bit width on the energy consumption of various sorting algorithms, we demonstrate that the data obtained using EACOF provides interesting, sometimes counter-intuitive, insights. All the code is available online under an open source license. http://github.com/eaco

    Controlling internal barrier in low loss BaTiO3 supercapacitors

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    Supercapacitor behavior has been reported in a number of oxides including reduced BaTiO3 ferroelectric ceramics. These so-called giant properties are however not easily controlled. We show here that the continuous coating of individual BaTiO3 grains by a silica shell in combination with spark plasma sintering is a way to process bulk composites having supercapacitor features with low dielectric losses and temperature stability. The silica shell acts both as an oxidation barrier during the processing and as a dielectric barrier in the final composite

    Observational Constraints on First-Star Nucleosynthesis. I. Evidence for Multiple Progenitors of CEMP-no Stars

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    We investigate anew the distribution of absolute carbon abundance, AA(C) =logâĄâ€‰Ï”= \log\,\epsilon (C), for carbon-enhanced metal-poor (CEMP) stars in the halo of the Milky Way, based on high-resolution spectroscopic data for a total sample of 305 CEMP stars. The sample includes 147 CEMP-ss (and CEMP-r/s) stars, 127 CEMP-no stars, and 31 CEMP stars that are unclassified, based on the currently employed [Ba/Fe] criterion. We confirm previous claims that the distribution of AA(C) for CEMP stars is (at least) bimodal, with newly determined peaks centered on AA(C)=7.96=7.96 (the high-C region) and AA(C)=6.28 =6.28 (the low-C region). A very high fraction of CEMP-ss (and CEMP-r/s) stars belong to the high-C region, while the great majority of CEMP-no stars reside in the low-C region. However, there exists complexity in the morphology of the AA(C)-[Fe/H] space for the CEMP-no stars, a first indication that more than one class of first-generation stellar progenitors may be required to account for their observed abundances. The two groups of CEMP-no stars we identify exhibit clearly different locations in the AA(Na)-AA(C) and AA(Mg)-AA(C) spaces, also suggesting multiple progenitors. The clear distinction in AA(C) between the CEMP-ss (and CEMP-r/sr/s) stars and the CEMP-no stars appears to be $as\ successful,and, and likely\ more\ astrophysically\ fundamental$, for the separation of these sub-classes as the previously recommended criterion based on [Ba/Fe] (and [Ba/Eu]) abundance ratios. This result opens the window for its application to present and future large-scale low- and medium-resolution spectroscopic surveys.Comment: 26pages, 7 figures, and 3 Tables ; Accepted for publication in ApJ; added more data and corrected minor inconsistencies existed in the compiled data of the previous studie

    Rice genetic marker database: An identification of single nucleotide polymorphism (SNP) and quantitative trait loci (QTL) markers

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    The National Academy of Agricultural Science (NAAS) has developed a web-based genetic marker system to provide information about SNP and QTL markers in rice. The SNP marker database provides 7,227 SNP markers including location information on chromosomes by using genetic map. It allows users to access a detailed characterization table of 12,829 potential SNPs in 3,356 genes. The QTL marker database provides 175 QTL markers information with 942 polymorphic markers on each of the12 chromosomes in rice. Users are assisted in tracing any new structures of the chromosomes and gene positional functions through comparisons using specific SNP and QTL markers

    Screening and inplane magnetoresistance of anisotropic two-dimensional gas

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    In order to split the influence of the orbital and spin effects on the inplane magnetoresistance of a quasi two-dimensional gas we derive its linear response function and dielectric function for the case of anisotropic effective mass. This result is used for the calculation of elastic transport relaxation time of a quasi two dimensional system in a parallel magnetic field. The relaxation time is proved to be isotropic in the low density limit for the case of charged impurity scattering, allowing to separate the two contributions.Comment: as published. 4 pages, 1 figur

    C-GOALS II. Chandra Observations of the Lower Luminosity Sample of Nearby Luminous Infrared Galaxies in GOALS

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    We analyze Chandra X-ray observatory data for a sample of 63 luminous infrared galaxies (LIRGs), sampling the lower-infrared luminosity range of the Great Observatories All-Sky LIRG survey (GOALS), which includes the most luminous infrared selected galaxies in the local universe. X-rays are detected for 84 individual galaxies within the 63 systems, for which arcsecond resolution X-ray images, fluxes, infrared and X-ray luminosities, spectra and radial profiles are presented. Using X-ray and MIR selection criteria, we find AGN in (31±\pm5)% of the galaxy sample, compared to the (38±\pm6)% previously found for GOALS galaxies with higher infrared luminosities (C-GOALS I). Using mid-infrared data, we find that (59±\pm9)% of the X-ray selected AGN in the full C-GOALS sample do not contribute significantly to the bolometric luminosity of the host galaxy. Dual AGN are detected in two systems, implying a dual AGN fraction in systems that contain at least one AGN of (29±\pm14)%, compared to the (11±\pm10)% found for the C-GOALS I sample. Through analysis of radial profiles, we derive that most sources, and almost all AGN, in the sample are compact, with half of the soft X-ray emission generated within the inner ∌1\sim 1 kpc. For most galaxies, the soft X-ray sizes of the sources are comparable to those of the MIR emission. We also find that the hard X-ray faintness previously reported for the bright C-GOALS I sources is also observed in the brightest LIRGs within the sample, with LFIR>8×1010L_{\rm FIR}>8\times10^{10} L⊙_{\odot}.Comment: 24 pages, 13 figures, 11 tables, accepted for publication in A&
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