13,047 research outputs found

    Photovoltaic array: Power conditioner interface characteristics

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    The electrical output (power, current, and voltage) of flat plate solar arrays changes constantly, due primarily to changes in cell temperature and irradiance level. As a result, array loads such as dc-to-ac power conditioners must be capable of accommodating widely varying input levels while maintaining operation at or near the maximum power point of the array. The array operating characteristics and extreme output limits necessary for the systematic design of array load interfaces under a wide variety of climatic conditions are studied. A number of interface parameters are examined, including optimum operating voltage, voltage energy, maximum power and current limits, and maximum open circuit voltage. The effect of array degradation and I-V curve fill factor or the array power conditioner interface is also discussed. Results are presented as normalized ratios of power conditioner parameters to array parameters, making the results universally applicable to a wide variety of system sizes, sites, and operating modes

    VTOL in ground effect flows for closely spaced jets

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    Results of a series of in ground effect twin jet tests are presented along with flow models for closely spaced jets to help predict pressure and upwash forces on simulated aircraft surfaces. The isolated twin jet tests revealed unstable fountains over a range of spacings and jet heights, regions of below ambient pressure on the ground, and negative pressure differential in the upwash flow field. A separate computer code was developed for vertically oriented, incompressible jets. This model more accurately reflects fountain behavior without fully formed wall jets, and adequately predicts ground isobars, upwash dynamic pressure decay, and fountain lift force variation with height above ground

    Program on Earth Observation Data Management Systems (EODMS)

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    An assessment was made of the needs of a group of potential users of satellite remotely sensed data (state, regional, and local agencies) involved in natural resources management in five states, and alternative data management systems to satisfy these needs are outlined. Tasks described include: (1) a comprehensive data needs analysis of state and local users; (2) the design of remote sensing-derivable information products that serve priority state and local data needs; (3) a cost and performance analysis of alternative processing centers for producing these products; (4) an assessment of the impacts of policy, regulation and government structure on implementing large-scale use of remote sensing technology in this community of users; and (5) the elaboration of alternative institutional arrangements for operational Earth Observation Data Management Systems (EODMS). It is concluded that an operational EODMS will be of most use to state, regional, and local agencies if it provides a full range of information services -- from raw data acquisition to interpretation and dissemination of final information products

    Orchard Day, August 18, 1955; Results of Fruit Research

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    Storing peaches / Donald Comin -- Trends in storages / Donald Comin -- Grape varieties ; Grape soil management and fertilization ; Nitrogen fertilizers for apple trees / J. M. Beattie -- Colorset on Golden Delicious and Grimes ; Planting distance influence on yield of apples ; Harvest dates for apples ; Summer varieties of apples ; Pre-harvest spraying for Baldwin / C. W. Ellenwood -- Peach investigations ; The blueberry planting ; Strawberry studies ; Plum varieties and culture ; Grape weed control studies / R. G. Hill, Jr. -- Semi-dwarf apple trees in Ohio / Freeman S. Howlett and T. E. Fowler -- The Franklin Apple / Freeman S. Howlett and C. W. Ellenwood -- Status of intermediate (trunk-forming) stocks for the apple ; Pruning the newly planted apple tree ; Status of the pear industry in Ohio / Freeman S. Howlett -- Pear variety collection indicates several deserve limited trial / Freeman S. Howlett and C. W. Ellenwoo

    Realistic Standard Model Fermion Mass Relations in Generalized Minimal Supergravity (GmSUGRA)

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    Grand Unified Theories (GUTs) usually predict wrong Standard Model (SM) fermion mass relation m_e/m_{\mu} = m_d/m_s toward low energies. To solve this problem, we consider the Generalized Minimal Supergravity (GmSUGRA) models, which are GUTs with gravity mediated supersymmetry breaking and higher dimensional operators. Introducing non-renormalizable terms in the super- and K\"ahler potentials, we can obtain the correct SM fermion mass relations in the SU(5) model with GUT Higgs fields in the {\bf 24} and {\bf 75} representations, and in the SO(10) model. In the latter case the gauge symmetry is broken down to SU(3)_C X SU(2)_L X SU(2)_R X U(1)_{B-L}, to flipped SU(5)X U(1)_X, or to SU(3)_C X SU(2)_L X U(1)_1 X U(1)_2. Especially, for the first time we generate the realistic SM fermion mass relation in GUTs by considering the high-dimensional operators in the K\"ahler potential.Comment: JHEP style, 29 pages, no figure,references adde

    Fruit crops, 1982: a summary of research

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    Influence of six rootstocks and herbicides on growth, cropping, and fruit quality of Blaxtayman apple trees / David C. Ferree and Robert G. Hill, Jr. -- Tree performance and yield efficiency of several apple cultivars on M9 and M9 interstems / D. C. Ferree -- Chemical induction of lateral shoots on young apple trees / S. C. Myers and D. C. Ferree -- The influence of urea sprays, mulch, and pruning on apple tree decline / G. A. Cahoon and C. W. Donoho, Jr. -- Influence of fireblight and ambrosia beetle on several apple cultivars on M9 and M9 interstems / F. R. Hall, M. A. Ellis, and D. C. Ferree -- A model study of the effect of wind on air sprayer jets / R. D. Fox, D. L. Reichard, and R. D. Brazee -- A comparative study of selected vineyard training and pruning systems for 'Concord' grapevines / G. A. Cahoon -- Effects of selected soil applied herbicides on grapes / Jomo MacDermot and Garth A. Cahoon -- Evaluation of aromatic compounds and virgin females as attractants for rose chafer / Roger N. Williams, Terrence P. McGovern, and Michael Klein -- Botrytis cinerea "gray mold" isolates from strawberry resistant to benlate in Ohio / P. Tanboon-Ek and M. A. Elli
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