1,157 research outputs found

    Solar cell and circuit array and process for nullifying magnetic fields Patent

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    Negation of magnetic fields produced by thin waferlike circuit elements in space vehicle

    Comparative values of advanced space solar cells

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    A methodology for deriving a first order dollar value estimate for advanced solar cells which consists of defining scenarios for solar array production and launch to orbit and the associated costs for typical spacecraft, determining that portion affected by cell design and performance and determining the attributable cost differences is presented. Break even values are calculated for a variety of cells; confirming that efficiency and related effects of radiation resistance and temperature coefficient are major factors; array tare mass, packaging and packing factor are important; but cell mass is of lesser significance. Associated dollar values provide a means of comparison

    Recommendations of OSTA Flight Technology Improvement Workshop-Power Subsystems panel

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    The recommendations of the power subsystems panel are discussed; The thrust is directed at radiometric problems. Areas that need development are defined for both spacecraft power subsystems and power supplies for experiments and instruments

    Unfulfilled technology needs in space power systems

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    Major power system technology development needs related to the solution of currently existing problems are defined. The identified problems were initially listed and categorized by technical area. They were then translated into terms of technology development requirements and consolidated where commonality was found. From these requirements, a set of ten specific recommendations for technology development was formulated

    Early Learning Innovation Fund Evaluation Final Report

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    This is a formative evaluation of the Hewlett Foundation's Early Learning Innovation Fund that began in 2011 as part of the Quality Education in Developing Countries (QEDC) initiative.  The Fund has four overarching objectives, which are to: promote promising approaches to improve children's learning; strengthen the capacity of organizations implementing those approaches; strengthen those organizations' networks and ownership; and grow 20 percent of implementing organizations into significant players in the education sector. The Fund's original design was to create a "pipeline" of innovative approaches to improve learning outcomes, with the assumption that donors and partners would adopt the most successful ones. A defining feature of the Fund was that it delivered assistance through two intermediary support organizations (ISOs), rather than providing funds directly to implementing organizations. Through an open solicitation process, the Hewlett Foundation selected Firelight Foundation and TrustAfrica to manage the Fund. Firelight Foundation, based in California, was founded in 1999 with a mission to channel resources to community-based organizations (CBOs) working to improve the lives of vulnerable children and families in Africa. It supports 12 implementing organizations in Tanzania for the Fund. TrustAfrica, based in Dakar, Senegal, is a convener that seeks to strengthen African-led initiatives addressing some of the continent's most difficult challenges. The Fund was its first experience working specifically with early learning and childhood development organizations. Under the Fund, it supported 16 such organizations: one in Mali and five each in Senegal, Uganda and Kenya. At the end of 2014, the Hewlett Foundation commissioned Management Systems International (MSI) to conduct a mid-term evaluation assessing the implementation of the Fund exploring the extent to which it achieved intended outcomes and any factors that had limited or enabled its achievements. It analyzed the support that the ISOs provided to their implementing organizations, with specific focus on monitoring and evaluation (M&E). The evaluation included an audit of the implementing organizations' M&E systems and a review of the feasibility of compiling data collected to support an impact evaluation. Finally, the Foundation and the ISOs hoped that this evaluation would reveal the most promising innovations and inform planning for Phase II of the Fund. The evaluation findings sought to inform the Hewlett Foundation and other donors interested in supporting intermediary grant-makers, early learning innovations and the expansion of innovations. TrustAfrica and Firelight Foundation provided input to the evaluation's scope of work. Mid-term evaluation reports for each ISO provided findings about their management of the Fund's Phase I and recommendations for Phase II. This final evaluation report will inform donors, ISOs and other implementing organizations about the best approaches to support promising early learning innovations and their expansion. The full report outlines findings common across both ISOs' experience and includes recommendations in four key areas: adequate time; appropriate capacity building; advocacy and scaling up; and evaluating and documenting innovations. Overall, both Firelight Foundation and TrustAfrica supported a number of effective innovations working through committed and largely competent implementing organizations. The program's open-ended nature avoided being prescriptive in its approach, but based on the lessons learned in this evaluation and the broader literature, the Hewlett Foundation and other donors could have offered more guidance to ISOs to avoid the need to continually relearn some lessons. For example, over the evaluation period, it became increasingly evident that the current context demands more focused advance planning to measure impact on beneficiaries and other stakeholders and a more concrete approach to promoting and resourcing potential scale-up. The main findings from the evaluation and recommendations are summarized here

    Radiation Damage in Polarized Ammonia Solids

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    Solid NH3 and ND3 provide a highly polarizable, radiation resistant source of polarized protons and deuterons and have been used extensively in high luminosity experiments investigating the spin structure of the nucleon. Over the past twenty years, the UVA polarized target group has been instrumental in producing and polarizing much of the material used in these studies, and many practical considerations have been learned in this time. In this discussion, we analyze the polarization performance of the solid ammonia targets used during the recent JLab Eg4 run. Topics include the rate of polarization decay with accumulated charge, the annealing procedure for radiation damaged targets to recover polarization, and the radiation induced change in optimum microwave frequency used to polarize the sample. We also discuss the success we have had in implementing frequency modulation of the polarizing microwave frequency.Comment: 5 pages, 6 figures. XIIth International Workshop on Polarized Sources, Targets and Polarimetr

    Firelight Foundation: An interim evaluation report of the Early Learning Innovation Fund

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    The Hewlett Foundation in 2014 selected Management Systems International (MSI) to implement a midterm evaluation of the Early Learning Innovation Fund. This evaluation explores the concept and design of the Fund; progress in achieving the Hewlett Foundation's four intermediary outcomes; and Firelight's implementation of the innovation fund with a focus on its approach to capacity building and expanding innovative programs. This evaluation also reviews the quality of the sub-grantees' monitoring and evaluation (M&E) systems and explores the potential of conducting an impact evaluation of sub-grantee activities

    Synchronous orbit power technology needs

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    The needs are defined for future geosynchronous orbit spacecraft power subsystem components, including power generation, energy storage, and power processing. A review of the rapid expansion of the satellite communications field provides a basis for projection into the future. Three projected models, a mission model, an orbit transfer vehicle model, and a mass model for power subsystem components are used to define power requirements and mass limitations for future spacecraft. Based upon these three models, the power subsystems for a 10 kw, 10 year life, dedicated spacecraft and for a 20 kw, 20 year life, multi-mission platform are analyzed in further detail to establish power density requirements for the generation, storage and processing components of power subsystems as related to orbit transfer vehicle capabilities. Comparison of these requirements to state of the art design values shows that major improvements, by a factor of 2 or more, are needed to accomplish the near term missions. However, with the advent of large transfer vehicles, these requirements are significantly reduced, leaving the long lifetime requirement, associated with reliability and/or refurbishment, as the primary development need. A few technology advances, currently under development, are noted with regard to their impacts on future capability
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