Search results for "River"
showing 10 items of 564 documents
Experimental observation of horizontal coherent turbulent structures in a straight flume
2009
The present paper describes results of laboratory experiments carried out to investigate the evolution of horizontal coherent turbulent structures for different roughness conditions of channel walls. The occurrence of turbulent events (inward interaction, ejection, sweep and burst) is identified through the conditioned quadrant analysis. The filtered data set is used to determine the probability density distribution of each turbulent event. Particular attention is focused on sweep and ejection events and peculiar maps showing the distributions of the horizontal Reynolds shear stress, for each examined experimental condition, are also presented and discussed.
Effects of submerged vegetation on flow and turbulence characteristics at the apex bend of a meandering flume
2020
Understanding flow characteristics and turbulent structure in the presence of vegetation is important with respect to environmental processes as sediment transport and mixing of transported quantities. In the present paper attention is focused on the kinematic and turbulent processes in presence of flexible submerged vegetation. In particular, the effect of vegetation on the flux of mass distribution and the process of transport is investigated. The analysis is performed with the aid of detailed experimental data collected in a laboratory channel both in the absence and in presence of flexible and submerged vegetation. Results essentially confirms that mass exchanges in the presence of vege…
Cross-sectional flow and bed shear stress: application of the depth-averaged momentum equation in a meandering laboratory flume
2014
Vegetation against erosion downstream of a hydraulic structure
2016
The present work shows the effects of vegetation on sediment transport process. The volume of sediments transported at different time steps is determined by applying a numerical model previously developed [4] and the model parameters are calibrated by using the experimental data.
Analysis of local scour downstream of bed sills: preliminary results of an experimental work
2006
Bed sills are often used to limit bed degradation, to control bed erosion around bridge piers or downstream stilling basins of dams. In this paper, the local scour that takes place downstream of the bed sill, in addition to the general erosion process, is examined. The data collected during experimental work are used to analyse the applicability of the relationship found in the literature and to define the relation between the maximum scour depth and the flow rate.
Studio dell’interazione corrente-vegetazione in un alveo meandriforme di elevata ampiezza in presenza di vegetazione sommersa matura e non ed al vari…
Simulation d’un Affichage Tête Haute - Réalité Augmentée pour l’aide visuelle à la conduite automobile
2016
Head-Up Display is the emerging solution for visual aid while driving a car, especially during reduced visibility conditions, such as bad weather or when the road is poorly lighted. The HUD device allows to project virtual information in the central field of view of the driving scene, enabling the driver to keep his attention on the road. The visual perception of the driver is therefore augmented, with a coexistence between the real and virtual world. However, it is necessary to ensure an optimal setting in order to guarantee the good perception of the virtual information, and allow drivers to take appropriate actions at the right moment. This thesis project is dedicated to study three impo…
A microplate version of the SOS/umu-test for rapid detection of genotoxins and genotoxic potentials of environmental samples
1991
Abstract The umu-microtest is a miniaturized automated short-term test version proposed for screening of umuC-dependent mutagenic potentials of chemicals relevant to environmental pollution, river water and industrial waste water. The test is based on the SOS/umu-test and has been modified in order to allow extensive testing of environmental samples. Genetically engineered Salmonella typhimurium (TA1535/pSK1002) are incubated on a microplate rotor in a sloping position for 2 h with the test samples, followed by addition of fresh culture medium to reach a 10-fold dilution of the incubation medium. 2 h later, the activity of the β-galactosidase, which reflects umuC induction, is determined co…
Distribution and characteristics of Listeria monocytogenes isolates from surface waters of the South Nation River Watershed, Ontario, Canada
2007
ABSTRACT Listeria monocytogenes is a facultative intracellular pathogen thought to be widely distributed in the environment. We investigated the prevalence and characteristics of L. monocytogenes isolates from surface waters derived from catchments within the South Nation River watershed (Ontario, Canada). This watershed is dominated by urban and rural development, livestock and crop production, and wildlife habitats. From June to November 2005, a total of 314 surface water samples were collected biweekly from 22 discrete sampling sites characterized by various upstream land uses. Presumptive Listeria spp. were isolated using a selective enrichment and isolation procedure, and 75 L. monocyt…