27,196 research outputs found

    Claim your space: re-placing spaces to better meet the needs of the net generation

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    The challenge for the Reid Library at The University of Western Australia was the transformation of a 1960s building into a welcoming space with services and facilities appropriate for a more technologically demanding generation. A key issue was how to balance the continuing need for access to physical collections with the rapidly expanding demand for new kinds of learning spaces and facilities oriented towards on-line and collaborative learning and research. This paper outlines the approach taken to identify client needs (both physical and virtual), define and propose new service models, and transform learning spaces while maintaining access to physical collections

    Star Formation History since z = 1.5 as Inferred from Rest-Frame Ultaviolet Luminosity Density Evolution

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    We investigate the evolution of the universal rest-frame ultraviolet luminosity density from z = 1.5 to the present. We analyze an extensive sample of multicolor data (U', B, V = 24.5) plus spectroscopic redshifts from the Hawaii Survey Fields and the Hubble Deep Field. Our multicolor data allow us to select our sample in the rest-frame ultraviolet (2500 angstrom) over the entire redshift range to z = 1.5. We conclude that the evolution in the luminosity density is a function of the form (1+z)^{1.7\pm1.0} for a flat lambda cosmology and (1+z)^{2.4\pm1.0} for an Einstein-de Sitter cosmology.Comment: 12 pages, 7 figs, 5 tables, submitted to A

    Solar cell radiation response near the interface of different atomic number materials

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    The response of cobalt 60 irradiated N/P silicon solar cells was measured as a function of the atomic number of the medium adjacent to the cell and the direction of the gamma ray beam. The interpositioning of various thicknesses of aluminum between the adjacent material and the cell had the effect of moving the cell to various locations in an approximate monatomic numbered medium. Using this technique the solar cell response was determined at various distances from the interface for gold and beryllium. The results were compared with predictions based upon ionization chamber measurements of dose perturbations in aluminum and found to agree within five percent. Ionization chamber data was then used to estimate the influence of various base contact materials

    A combined R-matrix eigenstate basis set and finite-differences propagation method for the time-dependent Schr\"{od}dinger equation: the one-electron case

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    In this work we present the theoretical framework for the solution of the time-dependent Schr\"{o}dinger equation (TDSE) of atomic and molecular systems under strong electromagnetic fields with the configuration space of the electron's coordinates separated over two regions, that is regions II and IIII. In region II the solution of the TDSE is obtained by an R-matrix basis set representation of the time-dependent wavefunction. In region IIII a grid representation of the wavefunction is considered and propagation in space and time is obtained through the finite-differences method. It appears this is the first time a combination of basis set and grid methods has been put forward for tackling multi-region time-dependent problems. In both regions, a high-order explicit scheme is employed for the time propagation. While, in a purely hydrogenic system no approximation is involved due to this separation, in multi-electron systems the validity and the usefulness of the present method relies on the basic assumption of R-matrix theory, namely that beyond a certain distance (encompassing region II) a single ejected electron is distinguishable from the other electrons of the multi-electron system and evolves there (region II) effectively as a one-electron system. The method is developed in detail for single active electron systems and applied to the exemplar case of the hydrogen atom in an intense laser field.Comment: 13 pages, 6 figures, submitte

    Some consequences of intense electromagnetic wave injection into space plasmas

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    The future possibility of actively testing the current understanding of how energetic particles may be accelerated in space or dumped from the radiation belts using intense electromagnetic energy from ground based antennas is discussed. The ground source of radiation is merely a convenience. A space station source for radiation that does not have to pass through the atmosphere and lower ionosphere, is an attractive alternative. The text is divided into two main sections addressing the possibilities of: (1) accelerating electrons to fill selected flux tubes above the Kennel-Petscheck limit for stably trapped fluxes, and (2) using an Alfven maser to cause rapid depletion of energetic protons or electrons from the radiation belts

    High Voltage CMOS Control Interface for Astronomy - Grade Charged Coupled Devices

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    The Pan-STARRS telescope consists of an array of smaller mirrors viewed by a Gigapixel arrays of CCDs. These focal planes employ Orthogonal Transfer CCDs (OTCCDs) to allow on-chip image stabilization. Each OTCCD has advanced logic features that are controlled externally. A CMOS Interface Device for High Voltage has been developed to provide the appropiate voltage signal levels from a readout and control system designated STARGRASP. OTCCD chip output levels range from -3.3V to 16.7V, with two different output drive strenghts required depending on load capacitance (50pF and 1000pF), with 24mA of drive and a rise time on the order of 100ns. Additional testing ADC structures have been included in this chip to evaluate future functional additions for a next version of the chip.Comment: 13 pages, 17 gigure

    Spectrophotometry of 2 complete samples of flat radio spectrum quasars

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    Spectrophotometry of two complete samples of flat-spectrum radio quasars show that for these objects there is a strong correlation between the equivalent width of the CIV wavelength 1550 emission line and the luminosity of the underlying continuum. Assuming Friedmann cosmologies, the scatter in this correlation is a minimum for q (sub o) is approximately 1. Alternatively, luminosity evolution can be invoked to give compact distributions for q (sub o) is approximately 0 models. A sample of Seyfert galaxies observed with IUE shows that despite some dispersion the average equivalent width of CIV wavelength 1550 in Seyfert galaxies is independent of the underlying continuum luminosity. New redshifts for 4 quasars are given

    What will probation practice look like in 2020?

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    In this short comment piece the authors attempt to visualise what probation practice might look like in the year 2020 through an account of a typical working day in the life of a CRC and NPS worker respectively
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