3,900 research outputs found

    Some preliminary results of the fine structure profiles of radio refractivity near the surface at Ota, Southwest Nigeria

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    Some preliminary results are presented of the fine structure profiles of surface radio refractivity, Ns, over Ota, Southwest Nigeria (6° 42'N, 3° 14'E) computed from in-situ, one minute interval measurements of surface pressure, temperature and relative humidity. A wireless Davis Vantage Pro2 Weather Station instrument installed at the Department of Physics, Covenant University, Ota in April 2012, was used to obtain the measured variables. Hourly, daily and monthly average values of surface water vapour density, dry, wet and total radio refractivity were obtained for the months of April 2012 to March 2013. The distance to the radio horizon for a given transmitter height may be deduced from the observation that Ns is well correlated with the gradient of refractivity over the first kilometer above ground. Refractivity gradients utilized for the work were those obtained in a previous work for Oshodi, a meteorological weather station near the coast and close to Ota

    The application of satellite generated data and multispectral analysis to regional planning and urban development

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    There are no author-identified significant results in this report

    Expanding the use of real-time electromagnetic tracking in radiation oncology.

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    In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery

    A survey of the School Housing Needs in Ellensburg, Washington

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    The improvement of school environment presents a different problem in each school. The problem facing the Ellensburg School District is one of providing more and better school housing. The purpose of this survey is to find out the condition of the present buildings, to make recommendations for improvements and alterations to the existing structures, to point out the needs for future building expansion. This survey is based on the results of an actual school census undertaken during November of this year

    Comparison of transabdominal ultrasound and electromagnetic transponders for prostate localization.

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    The aim of this study is to compare two methodologies of prostate localization in a large cohort of patients. Daily prostate localization using B-mode ultrasound has been performed at the Nebraska Medical Center since 2000. More recently, a technology using electromagnetic transponders implanted within the prostate was introduced into our clinic (Calypso(R)). With each technology, patients were localized initially using skin marks. Localization error distributions were determined from offsets between the initial setup positions and those determined by ultrasound or Calypso. Ultrasound localization data was summarized from 16619 imaging sessions spanning 7 years; Calypso localization data consists of 1524 fractions in 41 prostate patients treated in the course of a clinical trial at five institutions and 640 localizations from the first 16 patients treated with our clinical system. Ultrasound and Calypso patients treated between March and September 2007 at the Nebraska Medical Center were analyzed and compared, allowing a single institutional comparison of the two technologies. In this group of patients, the isocenter determined by ultrasound-based localization is on average 5.3 mm posterior to that determined by Calypso, while the systematic and random errors and PTV margins calculated from the ultrasound localizations were 3 - 4 times smaller than those calculated from the Calypso localizations. Our study finds that there are systematic differences between Calypso and ultrasound for prostate localization

    Technology requirements for an orbiting fuel depot: A necessary element of a space infrastructure

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    Advanced planning within NASA has identified several bold space exploration initiatives. The successful implementation of these missions will require a supporting space infrastructure which would include a fuel depot, an orbiting facility to store, transfer and process large quantities of cryogenic fluids. In order to adequately plan the technology development programs required to enable the construction and operation of a fuel depot, a multidisciplinary workshop was convened to assess critical technologies and their state of maturity. Since technology requirements depend strongly on the depot design assumptions, several depot concepts are presented with their effect on criticality ratings. Over 70 depot-related technology areas are addressed

    How can marketing theory be applied to policy design to deliver on sustainable agriculture in England?

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    Marketing theory was applied to develop a qualitative tool to predict levels of compliance based on involvement with the issue (policy objective) and involvement with the intervention (regulation). Based on an understanding farmer decision-making, the I3 Response Framework can help identify strategies that can strongly influence compliance, providing more efficient targeting of resources for policy. We report on further testing by application to the issue of water quality and the regulations around slurry storage as part of the Nitrate Pollution Prevention Regulations 2008 as applicable to dairy farmers in the Derwent catchment of North Yorkshire, EnglandPolicy, I3 Response Framework, involvement, water quality, slurry storage, Nitrogen Vulnerable Zone, regulation, Nitrate Pollution Prevention Regulations 2008, NPPR2008, Agricultural and Food Policy,
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