9,454 research outputs found
An overview on the role and potential of forage production on lowland organic livestock farms
This report was presented at the UK Organic Research 2002 Conference of the Colloquium of Organic Researchers (COR).
This paper outlines some of the factors influencing the level of forage production on organic lowland farms. Optimal forage production is achieved by maintaining soil fertility, providing a balance between N-fixing and N-demanding crops and producing sufficient quantities of quality feed to meet the requirements of the organic livestock enterprise. A key objective for organic systems is to increase the efficiency of forage production by improving the nutrient input/output balance of the wholefarm system. Improving forage quality reduces the requirement for external feed sources, leading to increased self-sufficiency in the wholefarm system. Legumes provide the main source of nitrogen for forage production with energy shortage and an erratic supply of protein the main limiting factors in the provision of balanced diets from home-grown crops
Wind-tunnel tests of wide-chord teetering rotors with and without outboard flapping hinges
Wind tunnel tests of aeroelastically designed helicopter rotor models were conducted to obtain rotor aerodynamic performance and dynamic response data pertaining to two-bladed teetering rotors with a wider chord and lower hover tip speed than currently employed on production helicopters. The effects of a flapping hinge at 62 percent radius were also studied. Finally, the effects of changing tip mass on operating characteristics of the rotor with the outboard flapping hinge were examined. The models were tested at several shaft angles of attack for five advance ratios, 0.15, 0.25, 0.35, 0.40, and 0.45. For each combination of shaft angle and advance ratio, the rotor lift was varied over a wide range to include simulated maneuver conditions. At each test condition, rotor aerodynamic performance and dynamic response data were obtained. From these tests, it was found that wide-chord rotors may be subject to large control forces. An outboard flapping hinge may be used to reduce beamwise bending moments over a significant part of the blade radius without significantly affecting the chordwise bending moments
Best practice report – operation and maintenance requirements
Deliverable 3.6.3 from the MERiFIC Project
A report prepared as part of the MERiFIC Project
"Marine Energy in Far Peripheral and Island Communities"This report is a deliverable of MERiFIC Work Package 3.6: ‘Operation and Maintenance requirements’ and
has been produced as a cross border collaboration between IFREMER and the University of Exeter. The
report provides an overview of guidelines and recommendations for the management of O&M operations
necessary for an optimal exploitation of Marine energy plants, with a focus on the specific areas of South
West Cornwall, UK and Iroise sea, Brittany, France. An overview of the onshore infrastructures and ports
possibly suitable for management of such O&M operations is also provided. Management of scheduled and
unscheduled maintenance operations are discussed in their various aspects including site accessibility. It
should be noted that this topic, including weather window assessment for operations is discussed in more
details in the additional MERIFIC report D3.6.2: Best Practice for installation proceduresMERiFIC was selected under the European Cross-Border Cooperation Programme
INTERREG IV A France (Channel) – England, co-funded by the ERDF
Layer-resolved optical conductivity of Co|Pt multilayers
The complex optical conductivity tensor is calculated for the Co|Pt systems
by applying a contour integration technique within the framework of the
spin-polarized relativistic screened Korringa-Kohn-Rostoker method. It is shown
that the optical conductivity of the Co|Pt multilayer systems is dominated by
contributions arising from the Pt cap and/or substrate layers.Comment: 7 pages (LaTeX), 2 (a,b) figures (Encapsulated PostScript), J. Magn.
Magn. Materials, in pres
Bulletin 14 - Some Suggestions for the Teaching of Geography in the Grades
https://thekeep.eiu.edu/eiu_bulletin/1116/thumbnail.jp
Bulletin 14 - Some Suggestions for the Teaching of Geography in the Grades
https://thekeep.eiu.edu/eiu_bulletin/1116/thumbnail.jp
Analysis of a novel non-contacting waveguide backshort
A new non-contacting waveguide backshort has been developed for millimeter and submillimeter wave frequencies. The design consists of a metal bar with rectangular or circular holes cut into it, which is covered with a dielectric (mylar) layer to form a snug fit with the walls of a waveguide. Hole geometries are adjusted to obtain a periodic variation of the guide impedance on the correct length scale, in order to produce efficient reflection of RF power. It is a mechanically rugged design which can be easily fabricated for frequencies from 1 to 1000 GHz and is thus a sound alternative to the miniaturization of conventional non-contacting shorts. To aid in high-frequency design, a rigorous full-wave analysis has been completed, which will allow variations of the size, number and spacing of the holes to be easily analyzed. This paper will review the backshort design and the method developed for theoretical characterization, followed by a comparison of the experimental and numerical results. Low frequency models operating from 4-6 GHz are shown to demonstrate return loss of greater than -0.2 dB over a 33 percent bandwidth. The theory is in good agreement with measured data
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