123,156 research outputs found
Physical modelling of low-cost modifications to the Crump Weir in order to improve fish passage : evelopment of favourable swimming conditions and investigation of the hydrometric effect
No full textMore than 350 Crump-type weirs (which are triangular in profile) form part of the
Environment Agency's hydrometric network in rivers across England and Wales.
These weirs operate as effective measurement structures and are useful over a large
flow range. However, they also act as barriers that impede the passage of many
species of coarse fish within their natural habitat.
The primary aim of this research project was to recommend modifcations to Crump
weirs in order to improve fish passage, while still allowing the weirs to fulfll their
hydrometric purpose in a reliable way. It was an additional requirement that any
proposed solution(s) be both practical and achievable at low-cost. This is in contrast
to conventional fish pass solutions, that tend to be expensive, are generally not
hydrometrically rated, and most of which were not designed with coarse fish in
mind.
The method used was a model study conducted in the laboratory, which allowed for
a great number of layouts to be trialled. Laboratory research combined with fish
swimming data provides a basis for projecting successful fish ascents. Brimpton weir
on the River Enborne was chosen as a suitable reference on which to base laboratory
model tests.
The preferred arrangement (termed a `rotated-V' layout) was found to be a series of
baffles located on the downstream slope of the Crump weir. These baffles effectively
act as weirs at low
flows and roughness elements at high
flows. Each baffle has a
slot which helps to form a path of ascent for fish. The base closest to the crest was
set at the same height as the crest, as this led to optimum low velocities in the slots
on the downstream slope.
Extensive testing revealed that the proposed solution results in a change in a weir's
hydrometric characteristics. However, it was demonstrated that the deviation of the
coefficient of discharge is predictable. Therefore, it allows for reliable
flow measure-
ment to be achieved (subject to a standardised calibration trial using volumetric
flow
measurement techniques). In addition, a detailed measurement and analysis of wa-
ter velocities within the recommended solution strongly suggest that it substantially
improves on the fish passage capability of a Crump weir
Crump
No full textcrump1 n"There's a crump you're in." A peculiar sitting position. Occasional.DNE-citUsed IUsed IUsed ICRITChecked by Jordyn Hughes on Wed 29 Jun 201
crump
No full textcrump2 n[PT] TO CUT CRUMP, TO EXPLANATION: SMALL, CROOKED tREES SOMETIMES USED FOR FIRE WOOD.YesDNE-cit J. D. A. WIDDOWSONCOLLECTOR'S PERMANENT FILEUsed IUsed IUsed ICRAN, CRUNNICKChecked by Jordyn Hughes on Wed 29 Jun 201
Full Field Strain Analysis of Aircraft Sandwich Structures
No full textA study of the application of two full field optical strain analysis techniques to aircraft standard carbon fibrecomposites is carried out. The goal of the work is to assess the feasibility of using the techniques on full scaletests of secondary sandwich structure aircraft panels. The work concentrates on two techniques: Digital ImageCorrelation (DIC) and Thermoelastic Stress Analysis (TSA). The DIC work focuses on the accuracy of the strainmeasured using different correlation patterns and parameters and the TSA concentrates on the interpretation ofthe data from different surface ply configurations. The work shows that it is possible to obtain meaningful datafrom the two techniques and acts as the preliminary confirmation exercise prior to full scale testing
T. Crump, The Anthropology of Numbers
No full textCaveing Maurice. T. Crump, The Anthropology of Numbers. In: L'Homme, 1994, tome 34 n°130. pp. 155-158
Design and commission of an experimental test rig to apply a full-scale pressure load on composite sandwich panels representative of aircraft secondary structure
No full textThis paper describes the design of a test rig, which is used to apply a representative pressure load to a full-scale composite sandwich secondary aircraft structure. A generic panel was designed with features to represent those in the composite sandwich secondary aircraft structure. To provide full-field strain data from the panels, the test rig was designed for use with optical measurement techniques such as thermoelastic stress analysis (TSA) and digital image correlation (DIC). TSA requires a cyclic load to be applied to a structure for the measurement of the strain state; therefore, the test rig has been designed to be mounted on a standard servo-hydraulic test machine. As both TSA and DIC require an uninterrupted view of the surface of the test panel, an important consideration in the design is facilitating the optical access for the two techniques. To aid the test rig design a finite element (FE) model was produced. The model provides information on the deflections that must be accommodated by the test rig, and ensures that the stress and strain levels developed in the panel when loaded in the test rig would be sufficient for measurement using TSA and DIC. Finally, initial tests using the test rig have shown it to be capable of achieving the required pressure and maintaining a cyclic load. It was also demonstrated that both TSA and DIC data can be collected from the panels under load, which are used to validate the stress and deflection derived from the FE model
Crump (Helen J.). — Colonial Admiralty Jurisdiction in the Seventeenth Century
No full textCrump (Helen J.). — Colonial Admiralty Jurisdiction in the Seventeenth Century. In: Revue de l'histoire des colonies françaises, tome 19, n°84, Novembre-décembre 1931. p. 649
M. Marjorie Crump, The Epyllion from Theocritus to Ovid, 1931
No full textDelage Émile. M. Marjorie Crump, The Epyllion from Theocritus to Ovid, 1931. In: Revue des Études Anciennes. Tome 35, 1933, n°1. pp. 68-69
M. Marjorie Crump, The Epyllion from Theocritus to Ovid, 1931
No full textDelage Émile. M. Marjorie Crump, The Epyllion from Theocritus to Ovid, 1931. In: Revue des Études Anciennes. Tome 35, 1933, n°1. pp. 68-69
Crump (Helen J.), Colonial Admiralty Jurisdiction in the Seventeenth Centurty (Royal Empire Society studies, n° 5), 1931
No full textCoornaert Émile. Crump (Helen J.), Colonial Admiralty Jurisdiction in the Seventeenth Centurty (Royal Empire Society studies, n° 5), 1931. In: Revue d'histoire moderne, tome 9 N°14,1934. p. 354
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