34,553 research outputs found

    ERTS wideband tape recorder

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    The ERTS video bandwith tape recorder uses a rotary head to run the tape in transverse mode; the head wheel gives a head-to-tape surface speed of nearly 5080 centimeter per second. The electronics unit handles 15 megabit per second rate with a bit-error rate of 0.00001. An operational unit onboard ERTS A returned images from the 85 to 90 percent of the earth that are not available in real time

    Isotopic Biogeochemistry

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    An overview is provided of the biogeochemical research. The funding, productivity, personnel and facilities are reviewed. Some of the technical areas covered are: carbon isotopic records; isotopic studies of banded iron formations; isotope effects in microbial systems; studies of organic compounds in ancient sediments; and development in isotopic geochemistry and analysis

    Reconciling visions and realities of virtual working: findings from the UK chemicals industry

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    The emergence of advanced technologies such as Grid computing will, some suggest, allow the final realisation of visions of virtual organisations. This will, according to its advocates, have entirely positive impacts, creating communities of experts, increasing flexibility, reducing the need for travel and making communications more efficient by crossing boundaries of time and space. Such predictions about future patterns of virtual working are, unfortunately, rarely grounded in real working practices, and often neglect to account for both the rich and varied interpretations that may exist of what constitutes virtual working and the constraints and concerns of those who would do it. This chapter gives attention to the consequences of different views over what virtuality might mean in practice and, in particular, considers virtuality in relation to customer and supplier relationships in a competitive and commercial context. The discussion is based upon a three year study that investigated contrasting visions of what was technically feasible and might be organisationally desirable in the UK Chemicals industry. Through interviews with managers and staff of companies both large and small that research provided insights into the different meanings that organisations attribute to the virtuality of work and to the acceptability of potential implementations of a middleware technology. It was found that interpretations of virtuality amongst the potential users and participants were strongly influenced by established work practices and by previous experiences of relationships-at-a-distance with suppliers and customers. There was a sharp contrast with the enthusiastic visions of virtual working that were already being encapsulated in the middleware by the technical developers; visions of internet-only interaction were perceived as rigid, alienating from well-established ways of working with suppliers and customers and unworkable. In this chapter we shall capture these differences by making a distinction amongst compet

    Sedimentary organic molecules: Origins and information content

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    To progress in the study of organic geochemistry, we must dissect the processes controlling the composition of sedimentary organic matter. Structurally, this has proven difficult. Individual biomarkers can often be recognized, but their contribution to total organic materials is small, and their presence does not imply that their biochemical cell mates have survived. We are finding, however, that a combination of structural and isotopic lines of evidence provides new information. A starting point is provided by the isotopic compositions of primary products (degradation products of chlorophylls, alkenones derived from coccoliths). We find strong evidence that the isotopic difference between primary carbonate and algal organic material can be interpreted in terms of the concentration of dissolved CO2. Moreover, the isotopic difference between primary and total organic carbon can be interpreted in terms of characteristic isotopic shifts imposed by secondary processes (responsive, for example, to O2 levels in the depositional environment. In favorable cases, isotopic compositions of a variety of secondary products can be interpreted in terms of flows of carbon, and, therefore, in terms of specific processes and environmental conditions within the depositional environment

    Loss-tolerant operations in parity-code linear optics quantum computing

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    A heavy focus for optical quantum computing is the introduction of error-correction, and the minimisation of resource requirements. We detail a complete encoding and manipulation scheme designed for linear optics quantum computing, incorporating scalable operations and loss-tolerant architecture.Comment: 8 pages, 6 figure

    The health status of Irish honeybee colonies in 2006

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    peer-reviewedThis study assessed the health status of Irish honeybee colonies and provides a snapshot of the incidence of a number of important colony parasites/pathogens including: the mite Varroa destructor; three associated viruses (deformed wing virus (DWV), acute bee paralysis virus (ABPV) and Kashmir virus (KBV)); the tracheal mite Acarapis woodi; the microsporidian Nosema spp., and the insect Braula coeca. During June/July 2006, 135 samples of adult bees were collected from productive colonies throughout Ireland and standard techniques were used to determine the presence and absence of the parasites and pathogens. Varroa destructor was positively identified in 72.6% of the samples and was widely distributed. Although the samples were analysed for three viruses, DWV, ABPV and KBV, only DWV was detected (frequency = 12.5%). Acarapis woodi and Nosema spp. occurred in approximately 11% and 22% of the samples, respectively, while B. coeca, a wingless dipteran that was once common in Irish honeybee colonies, was very rare (3.7%). Samples where all the pathogens/parasites were jointly absent were statistically under-represented in Leinster and DWV was statistically over-represented in Munster. In Ulster, there was over-representation of the categories where all parasites/pathogens were jointly absent and for A. woodi, and underrepresentation of V. destructor.The project was funded by EU FEOGA and the National Apiculture Programme 2007–2010 of the Department of Agriculture, Food and the Marine

    Rapidity Gaps Between Jets

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    An excess of events with a rapidity gap between jets, over what would be expected from non-diffractive processes, has been observed at HERA. A process based on a perturbative QCD calculation of colour singlet exchange has been added to HERWIG. With this addition, HERWIG is able to describe the number of events with a gap between jets over the number without a gap. This gap fraction is predicted to rise at large rapidity intervals between jets which would only be visible if the detector coverage were increased.Comment: 5 pages including 3 figures. To appear in the conference proceedings of the Workshop "Future Physics at HERA

    Estimating the Benefits of Water Quality Improvements in the Upper Narragansett Bay

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    An EPA-sponsored study of the benefits to Rhode Island residents of the water quality improvement in the Upper Narragansett Bay showed that the estimated annual costs (2.9million)exceededtheexpectedannualbenefits(2.9 million) exceeded the expected annual benefits (2.0 million). That analysis evaluated only user benefits which were measured via expenditures; nonuser (intrinsic) benefits were not included. This study estimated the benefits to Rhode Island residents using the "Contingent Valuation" approach and responses from 435 residents to a 1985 survey about swimming and shellfishing. Aggregate annual benefits were estimated to be in the range of 30−60millionfor"swimmable"and30-60 million for "swimmable" and 30-70 million for "shellfishable" water quality, depending on the type of measure (mean or median) and survey format. Secondary objectives of the study were to test different versions of "willingness to pay" questions and compare mean and median values for measurement. Aside from payment vehicle bias, we found no evidence of serious bias.contingent valuation, pollution, water quality benefits, Environmental Economics and Policy, Resource /Energy Economics and Policy,

    What happened in 2002?

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    Presented at the 15th annual Central Plains irrigation conference and exposition proceedings on February 4-5, 2003 at the City Limits Convention Center in Colby, Kansas.Includes bibliographical references

    MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E

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    We report on the discovery of ionised gas filaments in the circum-galactic halo of the extremely metal-poor compact starburst SBS 0335-052E in a 1.5h integration with the MUSE integral-field spectrograph. We detect these features in Hα{\alpha} and [OIII] emission down to surface-brightness levels of 5×10−195 \times 10^{-19}erg s−1^{-1}cm−2^{-2}arcsec−2^{-2}. The filaments have projected diameters of 2.1 kpc and extend more than 9 kpc to the north and north-west from the main stellar body. We also detect extended nebular HeII λ\lambda4686 emission that brightens towards the north-west at the rim of a star-burst driven super-shell, suggestive of a locally enhanced UV radiation field due to shocks. We also present a velocity field of the ionised gas. The filaments appear to connect seamlessly in velocity space to the kinematical disturbances caused by the shell. Similar to high-zz star-forming galaxies, the ionised gas in this galaxy is dispersion dominated. We argue that the filaments were created via feedback from the starburst and that these ionised structures in the halo may act as escape channels for Lyman continuum radiation in this gas-rich system.Comment: Revised version after peer review. Accepted for publication in A&A letter
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