3,138 research outputs found

    Pastures in Vanuatu

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    Livestock Production/Industries,

    What are the Options for FSL in the NB Public System?

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    This text provides a short survey of the different FSL programs offered in public schools in New Brunswick under the jurisdiction of the English sector of the Department of Education, as well as data on student attendance.Ce texte présente les différents programmes de formation en français langue seconde offerts dans les écoles publiques du Nouveau-Brunswick qui se trouvent sous la juridiction du secteur anglophone ainsi que des données sur le taux de fréquentation des différents programmes

    Numerical Modeling Of Hohlraum Radiation Conditions: Spatial And Spectral Variations Due To Sample Position, Beam Pointing, And Hohlraum Geometry

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    View-factor simulations are presented of the spatially varying radiation conditions inside double-ended gold Hohlraums and single-ended gold Hohlraums (\u27\u27 halfraums \u27\u27) used in inertial confinement fusion and high-energy density physics experiments [J. Lindl, Phys. Plasmas 11, 339 (2004); M. D. Rosen, Phys. Plasmas 3, 1803 (1996)]. It is shown that in many circumstances, the common assumption that the Hohlraum \u27\u27 drive \u27\u27 can be characterized by a single temperature is too simplistic. Specifically, the radiation conditions seen by an experimental package can differ significantly from the wall reemission measured through diagnostic holes or laser entrance holes (LEHs) by absolutely calibrated detectors. Furthermore, even in situations where the radiation temperature is roughly the same for diagnostics and experimental packages, or for packages at different locations, the spectral energy distributions can vary significantly, due to the differing fractions of reemitting wall, laser hot spots, and LEHs seen from different locations. We find that the spatial variation of temperature and especially the differences between what diagnostics looking in the LEH measure versus the radiation temperature on wall-mounted experimental packages are generally greater for double-ended Hohlraums than for halfraums. View-factor simulations can also be used to explore experimental variables (halfraum length and geometry, sample position, and beam pointing) that can be adjusted in order to, for example, maximize the radiation flux onto a sample, or other package. In this vein, simulations of Hohlraums and halfraums with LEH shields are also presented. (c) 2005 American Institute of Physics

    Scalable solid-state quantum processor using subradiant two-atom states

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    We propose a realization of a scalable, high-performance quantum processor whose qubits are represented by the ground and subradiant states of effective dimers formed by pairs of two-level systems coupled by resonant dipole-dipole interaction. The dimers are implanted in low-temperature solid host material at controllable nanoscale separations. The two-qubit entanglement either relies on the coherent excitation exchange between the dimers or is mediated by external laser fields.Comment: 4 pages, 3 figure

    New Challenges For Wind Shock Models: The Chandra Spectrum Of The Hot Star Delta Orionis

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    The Chandra spectrum of delta Ori A shows emission lines from hydrogen- and helium-like states of Si, Mg, Ne, and O, along with N VII Lyalpha and lines from ions in the range Fe XVII-Fe XXI In contrast to the broad lines seen in zeta Pup and zeta Ori (850 +/- 40 and 1000 +/- 240 km s(-1) half-width at half-maximum [HWHM], respectively), these lines are broadened to only 430 +/- 60 km s(-1) HWHM. This is much lower than the measured wind terminal velocity of 2000 km s(-1). The forbidden, intercombination, and resonance (fir) lines from He-like ions indicate that the majority of the X-ray line emission does not originate at the base of the wind, in agreement with the standard wind shock models for these objects. However, in that model the X-ray emission is distributed throughout an expanding, X-ray-absorbing wind, and it is therefore surprising that the emission lines appear relatively narrow, unshifted, and symmetric. We compare the observed line profiles to recent detailed models for X-ray line pro le generation in hot stars, but none of them offers a fully satisfactory explanation for the observed line profiles

    220GHz wideband 3D imaging radar for concealed object detection technology development and phenomenology studies

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    Part of the research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 312745.We present a 220 GHz 3D imaging ‘Pathfinder’ radar developed within the EU FP7 project CONSORTIS (Concealed Object Stand-Off Real-Time Imaging for Security) which has been built to address two objectives: (i) to de-risk the radar hardware development and (ii) to enable the collection of phenomenology data with ~1 cm3 volumetric resolution. The radar combines a DDS-based chirp generator and self-mixing multiplier technology to achieve a 30 GHz bandwidth chirp with such high linearity that the raw point response is close to ideal and only requires minor nonlinearity compensation. The single transceiver is focused with a 30 cm lens mounted on a gimbal to acquire 3D volumetric images of static test targets & materials.Publisher PD

    A 220 GHz 3D imaging radar with sub-cm3 voxel resolution for security applications

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    Radars operating at high millimetre and sub-millimetre wave frequencies are promising candidates for security applications such as people screening since they offer the possibility to form 3D images through clothing with sufficient resolution to detect concealed objects. High spatial resolution of order 1 cm can be achieved using practically sized antennas and high range resolution can be achieved using wideband FMCW chirps, e.g. 30 GHz, to yield 0.5 cm range bins. We present a 220 GHz test-bed ‘Pathfinder’ radar which achieves sub-cm3 voxel resolution with very high signal fidelity. The radar is used to de-risk technology under development for next generation people screening systems.Postprin
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