3,691 research outputs found

    Has empowerment lost its power?

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    New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

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    An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined

    Effect of Pylon Wake with and Without Pylon Blowing on Propeller Thrust

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    Pylon trailing edge blowing was investigated as a means of alleviating the effects of the pylon wake on a pusher arrangement of an advanced single-rotation turboprop. Measurements were made of steady-state propeller thrust and pylon wake pressures and turbulence levels with and without blowing. Results show that the pylon trailing edge blowing practically eliminated the pylon wake, significantly reduced the pylon wake turbulence, and had a relatively small effect on the steady-state propeller thrust. The data are presented with a minimum of analysis

    Constitutional Law—Reimbursement of Utility Relocation Costs

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    In 1959 the state legislature passed a law enabling Washington to obtain federal-aid highway grants for the reimbursement of utility relocation costs incident to federal highway construction. In the recent case of Washington St. Hy. Comm\u27n. v. Pacific Northwest Bell Tel. Co., the Washington Supreme Court held this legislation to violate the state constitution

    Continuation of Mourning Dove Studies in Clark County, Arkansas, with Emphasis on Cyclical Behavioral Patterns

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    In conjunction with the U.S. Department of Interior, Fish and Wildlife Service, the Henderson State University Biology Department has continued a study of mourning doves in Clark County, Arkansas, with emphasis on cyclical behavioral patterns. Three hundred forty-three mourning doves were baited, trapped, and banded to obtain information concerning age, sex, populations, retraps, abnormalities, migrations, trap injuries, cyclical behavioral patterns, and other factors

    Nitrogen and phosphorus cycling strategies in two tidal freshwater macrophytes, Peltandra virginica and Spartina cynosuroides

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    Monotypic stands of the macrophytes Peltandra virginica and Spartina cynosuroides, which shared a common boundary, were studied at Sweethall Marsh, a tidal freshwater marsh located on the Pamunkey River within the Chesapeake Bay estuarine system, Virginia. Compartmental models indicate that both Peltandra and Spartina take up, internally cycle, and release to the environment, significant levels of nitrogen and phosphorus. Models also suggest that Peltandra and Spartina and their associated sediment compartments are capable of regulating nitrogen and phosphorus fluxes through their uptake and storage capacity. Nitrogen use efficiency was significantly higher in the shoots and roots of Spartina compared to Peltandra, while rhizome use efficiency was slightly higher in Peltandra. Phosphorus use efficiency was significantly higher in shoots, roots, and rhizomes of Spartina than in Peltandra. Lower use efficiency in Peltandra demonstrates a greater demand of nutrient per unit biomass than Spartina. Nitrogen and phosphorus recovery efficiency was higher in Peltandra. Efficiency indexes suggest that although Spartina appears to use nitrogen and phosphorus more efficiently for growth, Peltandra recovers and stores these nutrients more efficiently. Peltandra shoot, root, and rhizome tissue nutrient levels appear independent of sediment nitrogen and phosphorus availability. Spartina shoot, root, and rhizome nitrogen levels, however, appear dependent on sediment total nitrogen and total phosphorus. The relationship of Peltandra tissue nutrient levels to sediment availability is explained in terms of the rhizome storage capacity and reallocation of nitrogen and phosphorus to support productivity patterns. Spartina, however, must rely more on de novo root uptake to meet nutrient demands. Shoot, root, and rhizome nitrogen and phosphorus standing stocks were strongly correlated in both Peltandra and Spartina while sediment standing stocks were not. Nitrogen to phosphorus ratios were higher in the shoots than the roots and rhizomes of both Peltandra and Spartina reflecting the levels of nitrogen required to support photosynthesis. Nitrogen to phosphorus ratios varied over the sampling period, however appeared to converge on an optimum ratio. The correlation of nitrogen and phosphorus suggests an interaction between these nutrients although this relationship is unclear. Apparently both Peltandra and Spartina reallocate, as well as require, nitrogen and phosphorus in certain ratios which maximize productivity, uptake, and carbon assimilation

    Reduction of blade-vortex interaction noise using higher harmonic pitch control

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    An acoustics test using an aeroelastically scaled rotor was conducted to examine the effectiveness of higher harmonic blade pitch control for the reduction of impulsive blade-vortex interaction (BVI) noise. A four-bladed, 110 in. diameter, articulated rotor model was tested in a heavy gas (Freon-12) medium in Langley's Transonic Dynamics Tunnel. Noise and vibration measurements were made for a range of matched flight conditions, where prescribed (open-loop) higher harmonic pitch was superimposed on the normal (baseline) collective and cyclic trim pitch. For the inflow-microphone noise measurements, advantage was taken of the reverberance in the hard walled tunnel by using a sound power determination approach. Initial findings from on-line data processing for three of the test microphones are reported for a 4/rev (4P) collective pitch control for a range of input amplitudes and phases. By comparing these results to corresponding baseline (no control) conditions, significant noise reductions (4 to 5 dB) were found for low-speed descent conditions, where helicopter BVI noise is most intense. For other rotor flight conditions, the overall noise was found to increase. All cases show increased vibration levels

    An evaluation of the Department of Health’s Health and Social Care Volunteering Fund

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    The Health and Social Care Volunteering Fund (HSCVF) is an innovative programme that was established in 2009 by the Department of Health (DH) to build organisational and community capacity for volunteering through a national and local grant scheme. The HSCVF has offered both funds and tailored support to health and social care projects delivered by Voluntary, Community and Social Enterprise (VCSE) organisations. The HSCVF is managed by a partnership led by Ecorys and with expertise from leading national voluntary sector organisations: Attend, Community Service Volunteers (CSV) and Primetimers. To date the HSCVF has funded a total of 157 local and national projects, of which 114 are currently live. This report presents findings from an evaluation of the HSCVF with a specific focus on the 2010/2011 national and local projects, conducted by a team from the Institute for Health & Wellbeing at Leeds Metropolitan University. It presents evidence on the extent to which, how and in what ways the HSCVF programme has built organisational and community capacity across the national and local HSCVF projects, as well as on the health and social outcomes that resulted
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