16,556 research outputs found

    New Limits on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

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    We update the limit from the 90 GHz PIQUE ground-based polarimeter on the magnitude of any polarized anisotropy of the cosmic microwave radiation. With a second year of data, we have now limited both Q and U on a ring of 1 degree radius. The window functions are broad: for E-mode polarization, the effective l is = 191 +143 -132. We find that the E-mode signal can be no greater than 8.4 microK (95% CL), assuming no B-mode polarization. Limits on a possible B-mode signal are also presented.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter

    Evaluation of dental therapists undertaking dental examinations in a school setting in Scotland

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    Objective: To measure agreement between dental therapists and the Scottish gold-standard dentist undertaking National Dental Inspection Programme (NDIP) examinations. Methods: A study of interexaminer agreement between 19 dental therapists and the national gold-standard dentist was carried out. Pre-calibration training used the caries diagnostic criteria and examination techniques agreed by the British Association for the Study of Community Dentistry (BASCD). Twenty-three 5-year-old children (Primary 1) and 17 11-year-old children (Primary 7) children were examined. Agreement was assessed using kappa statistics on d 3 mft and D 3 MFT for P1 and P7 children, sensitivity and specificity values, and kappa statistics on d 3 t/D 3 T and ft/FT. Calibration data on P1 and P7 children from 2009–2012 involving dentists as examiners were used for comparison. Economic evaluation was undertaken using a cost minimization analysis approach. Results: The mean kappa score was 0.84 (SD 0.07) ranging from 0.69 to 0.94. All dental therapists scored good or very good agreement with the gold-standard dentist. This compares with historic NDIP calibration data with dentists, against the same gold-standard dentist, where the mean kappa value was 0.68 (SD 0.22) with a range of 0.35-1.00. The mean sensitivity score was 0.98 (SD 0.04) (range 0.88-1.0) and mean specificity score was 0.90 (SD 0.06) (range 0.78-0.96). Health economic analysis estimated that salary costs would be 33.6% lower if dental therapists were substituted for dentists in the year 2013, with an estimated saving of approximately £103 646 per annum on the national budget. Conclusion: We conclude that dental therapists show a high level of interexaminer agreement, and with the appropriate annual training and calibration, they could undertake dental examinations as part of the NDIP programme

    Near-infrared colors of minor planets recovered from VISTA - VHS survey (MOVIS)

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    The Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE) provide information about the surface composition of about 100,000 minor planets. The resulting visible colors and albedos enabled us to group them in several major classes, which are a simplified view of the diversity shown by the few existing spectra. We performed a serendipitous search in VISTA-VHS observations using a pipeline developed to retrieve and process the data that corresponds to solar system objects (SSo). The colors and the magnitudes of the minor planets observed by the VISTA survey are compiled into three catalogs that are available online: the detections catalog (MOVIS-D), the magnitudes catalog (MOVIS-M), and the colors catalog (MOVIS-C). They were built using the third data release of the survey (VISTA VHS-DR3). A total of 39,947 objects were detected, including 52 NEAs, 325 Mars Crossers, 515 Hungaria asteroids, 38,428 main-belt asteroids, 146 Cybele asteroids, 147 Hilda asteroids, 270 Trojans, 13 comets, 12 Kuiper Belt objects and Neptune with its four satellites. The colors found for asteroids with known spectral properties reveal well-defined patterns corresponding to different mineralogies. The distributions of MOVIS-C data in color-color plots shows clusters identified with different taxonomic types. All the diagrams that use (Y-J) color separate the spectral classes more effectively than the (J-H) and (H-Ks) plots used until now: even for large color errors (<0.1), the plots (Y-J) vs (Y-Ks) and (Y-J) vs (J-Ks) provide the separation between S-complex and C-complex. The end members A, D, R, and V-types occupy well-defined regions.Comment: 19 pages, 16 figure

    A national power infrastructure for charge-on-the-move: An appraisal for Great Britain

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    The electrification of road transportation is a necessary step for coping with climate change. Charge-on-the-move is considered to be a key enabling factor in moving towards electric vehicles. The development of individual charging devices for implementing in-motion charging has been rapid but their integration with the road infrastructure at national scale is still in need of more comprehensive consideration. This work aims to outline the performance requirements of a national power infrastructure suitable for implementing charge-on-the-move. From an estimation of electric vehicles’ power requirements in conjunction with Great Britain’s road traffic data the anticipated power demand is expected to be augmented by 16 GW. Furthermore, a simulation tool is proposed to investigate the application of dynamic charging and the effects of system design variables. Based on that, a possible charging layout is suggested. Such infrastructure involves 30 kW chargers, 1.5 m length apiece, installed every 2.1 m and 4.3 m on motorways and rural sections of road respectively. Finally, a strategic overview for Great Britain suggests that the installation of a nationwide charging infrastructure of this type could be economically viable. Indeed, the cost to develop the infrastructure to enable the electrification of 86% of car-miles in Great Britain is around £76 billion at present prices

    Fundamental Behavior of Electric Field Enhancements in the Gaps Between Closely Spaced Nanostructures

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    We demonstrate that the electric field enhancement that occurs in a gap between two closely spaced nanostructures, such as metallic nanoparticles, is the result of a transverse electromagnetic waveguide mode. We derive an explicit semianalytic equation for the enhancement as a function of gap size, which we show has a universal qualitative behavior in that it applies irrespective of the material or geometry of the nanostructures and even in the presence of surface plasmons. Examples of perfect electrically conducting and Ag thin-wire antennas and a dimer of Ag spheres are presented and discussed.Comment: 9 pages and 4 figure

    Synthesis of high-oxidation Y-Ba-Cu-O phases in superoxygenated thin films

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    It is known that solid-state reaction in high-pressure oxygen can stabilize high-oxidation phases of Y-Ba-Cu-O superconductors in powder form. We extend this superoxygenation concept of synthesis to thin films which, due to their large surface-to-volume ratio, are more reactive thermodynamically. Epitaxial thin films of YBa2Cu3O7δ\rm{YBa_2Cu_3O_{7-\delta}} grown by pulsed laser deposition are annealed at up to 700 atm O2_2 and 900^\circC, in conjunction with Cu enrichment by solid-state diffusion. The films show clear formation of Y2Ba4Cu7O15δ\rm{Y_2Ba_4Cu_7O_{15-\delta}} and Y2Ba4Cu8O16\rm{Y_2Ba_4Cu_8O_{16}} as well as regions of YBa2Cu5O9δ\rm{YBa_2Cu_5O_{9-\delta}} and YBa2_2Cu6_6O10δ_{10-\delta} phases, according to scanning transmission electron microscopy, x-ray diffraction and x-ray absorption spectroscopy. Similarly annealed YBa2Cu3O7δ\rm{YBa_2Cu_3O_{7-\delta}} powders show no phase conversion. Our results demonstrate a novel route of synthesis towards discovering more complex phases of cuprates and other superconducting oxides.Comment: Accepted for publication in Physical Review Material
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