Résultats de la recherche (29 résultats)

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  • Turbulent shear stresses in hydraulic jumps, bores and decelerating surges
  • Herein, a physical investigation was conducted in a relatively large rectangular channel. Hydraulic jumps and surges were generated by the rapid closure of a gate at the channel downstream end. The turbulent shear stresses were measured with high
  • temporal and spatial resolution in the jump flow. A comparison between the stationary hydraulic jump, hydraulic jump in translation and decelerating surge measurements showed some marked differences in terms of turbulent mixing. The results highlighted some
  • intense mixing beneath the jump front and roller for all configurations. The levels of turbulent stresses were one to two orders of magnitude larger than a critical threshold for sediment motion. The findings provide some insights into the hydraulic jump
  • migration processes in mobile bed channels, and the complex transformation from a moving jump into a stationary jump.
  • Flow-separation berms downstream of a hydraulic jump in a bedrock channel
  • The purpose of this paper is to report the first direct observation of the phenomenon of gravel berm formation, downstream of a hydraulic jump. As the observations were fortuitous, detailed measurements of hydraulic conditions were not possible
  • but estimates were obtained. These observations are compared with laboratory experiments and theory. The deposits have significance in constraining flood palaeoflow reconstructions as the presence of berms determines the former location of hydraulic jumps.
  • Field mapping and digital elevation modelling of submerged and unsubmerged hydraulic jump regions in a bedrock step-pool channel
  • The aim was to develop a systematic methodology to rapidly survey, digitize and visualize bed and water surface topographies of 2 common types of natural jump regions (submerged and unsubmerged) in a bedrock step-pool channel. In addition
  • to reducing uncertainty associated with qualitative observations, the data provide the basis for quantitative comparison of different natural jets and jumps with engineered jets and jumps. The digital elevation models highlight the importance of recognizing
  • Geostrophic wind over Cape York Peninsula and pressure jumps around the Gulf of Carpentaria
  • Pressure jumps, almost certainly due to interaction of opposing sea-breeze gravity currents, are very common in the nocturnal atmosphere of western Cape York Peninsula and the Gulf of Carpentaria in October. Most come from the east-northeast
  • Against all odds : poor people jumping scales and the genesis of an urban policy in Flanders, Belgium
  • The AA. use a critical approach to explain the emergence of an urban policy in Flanders. In the case of urban policy in Flanders, the processes of scalar reconfiguration come down to scale-jumping by actors concerned with the fate of disadvantaged
  • An analysis of pressure jumps at Luqa, Malta, in the years 1968-1972
  • -2m. Amino-acid ratios, archaeology, pollen and lithostratigraphy suggest that the sea later jumped to about +16m. The combination of the cooling and the large jump points to an East Antarctic ice surge, at 95 kyr BP.
  • Geographies of knowing, geographies of ignorance : jumping scale in Southeast Asia
  • Can the Greenland climatic jumps be identified in records from ocean and land?
  • New technology in producing maize, sorghum, cotton and groundnuts, while appropriate to poor farmers in high risk, low potential areas, still require a significant jump from traditional methods. (EMS).
  • of the diverse sources of information on the Net. Many of the sites listed are jumping-off points with links that can be quickly accessed on a'point and click basis. The main types of information are : current and recent weather data and forecasts; climate
  • Results from Monte Carlo studies suggest that the weighted spatial adaptive filter is at least as accurate as the unweighted filter for cases having smoothly changing parameters, but superior for cases having discontinuous, step-jump parameters
  • circulation. The cooling effect is more pronounced along segments over hotspots with close ridge displacement fabric and recurrent rift jumping, probably reflecting additional complications, including subaxial magma flow about plumes, or the presence
  • Based on the surface runoff, temperature and precipitation data over the last 50 years from eight representative rivers in Xinjiang, using Mann-Kendall trend and jump detection method, the paper investigated the long-term trend and jump point
  • implies that interventions decrease to a minimal non-regressive point, leading to the prediction that increases in insurgency or other changes are likely to lead to worsening conditions, and improvements require substantial jumps in intervention resources.
  • Adopting a critical perspective which eschews the temptation to jump to over-hasty conclusions, the paper looks at the contradictory mechanisms underlying regional economic integration and labor mobility in the NAFTA region.