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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Flow resistance in ploughed upland drains : narrow channels with uniform or composite roughness

Flintham, T. P. January 1988 (has links)
Ploughed upland drains are straight prismatic channels of low aspect ratio. The drains are either uniformly or compositely roughened. In compositely roughened drains the bed and side-walls are differentially roughened although each roughness type is homogeneous. Upland catchments, containing extensive ploughed drainage networks, are particularly prone to flash flooding and increased sediment yield. However, the basic hydraulic data necessary to route flow through the drainage network and improve the engineering design of stable drainage channels are currently unavailable. A logarithmic flow resistance equation is developed for low aspect ratio channels, where the effective Nikuradse equivalent grain size is known. Testing against field data indicates that the relationship successfully predicts the resistance to uniform flow through upland drains. The performance of eight composite roughness formulae to predict the mean velocity in differentially roughened channels is compared. The composite roughness equations involve dividing the cross-sectional flow area into a number of sub-areas. The different methods of cross-sectional area division are considered and their effect on mean velocity prediction examined. Preferences are indicated concerning composite roughness equations which predict the mean velocity in channels of simple cross-sectional shape. Empirical equations are derived to determine the mean bed and side-wall shear stresses in straight symmetrical trapezoidal and rectangular open channels, with uniform or composite roughness. The model proposed is appropriate for stable sub-critical and super-critical flows. The equations are based on data collected from laboratory channels and should be cautiously applied to larger scale channels. Using the mean shear stress model, a design procedure is proposed to improve drainage channel stability.
42

A study of the administration of the Channel Islands in the thirteenth and early fourteenth centuries based mainly on the assize rolls and other unprinted documents

Le Patourel, John January 1934 (has links)
No description available.
43

PARAMETER CHARACTERIZATION ON A TELEMETRY CHANNEL INCLUDING THE EFFECTS OF THE SPECULAR RAY

Dye, Ricky G., Horne, Lyman D. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The aeronautical channel model is a good candidate for modeling the effects of multipath interference of telemetry signals on test ranges. The aeronautical fading channel model is parameterized by the signal to noise ratio, the Doppler shift and time delay between the specular and direct components, the specular to direct power ratio, the direct to diffuse power ratio, and the bandwidth of the multipath fading process. Segments of weighting signal data measured during a test at Tyndall AFB provide data which can be used to determine typical values of the above parameters in a variety of telemetering environments. In this paper, the set of parameters which most closely model the actual telemetry channel using the Tyndall data is determined.
44

An investigation into the mechanisms of compound meandering channel flow

Greenhill, Rosemary Kate January 1992 (has links)
No description available.
45

Dynamic radio resource management algorithms and traffic models for emerging mobile communication systems

Lazaro de Barrio, Oscar January 2002 (has links)
No description available.
46

Studies on the biology of young fish

Townley, Mark January 1982 (has links)
No description available.
47

Radio local area networks : protocol design and performance analysis

Muriithi, Ndiritu January 1996 (has links)
No description available.
48

Antenna diversity-assisted adaptive wireless multiuser OFDM systems

Münster, Matthias January 2002 (has links)
No description available.
49

A geomorphological approach to the strategic management of river bank erosion : a case study of the Afon Dyfi

German, Sally Eloise January 2000 (has links)
No description available.
50

The fishery and ecology of the scallop Pecten maximus (L.) in Guernsey

Jory, Adam Matthew January 2000 (has links)
No description available.

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