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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 73 for “"Settling velocity"”.
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Primary sedimentation tank model with characterized settling velocity groups
… the separation of solids and liquid in primary settling tanks (PSTs) of wastewater treatment systems. These physical processes are described by various settling conditions such as discrete and flocculent settling, along with other phenomena such as flocculation, coagulation, ammonification or …
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Settling Velocity of Straight and Curved Rods at Low Reynolds Numbers in a Quiescent Fluid
… the effects of microfibre geometry on the settling velocity. Microfibres have been mathematically modelled as simple straight rods in the past to estimate their settling velocity; however, samples collected demonstrate complex geometries. One common geometric parameter of realistic …
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Numerical Simulations of Two -Way Coupling Effects in a Particle-Laden Turbulent Pipe Flow, And, Evaluation of the Equilibrium Eulerian Approach for the Evolution of Particle Concentration in Isotropic Turbulence
… to study particle preferential concentration and settling velocity in isotropic turbulence. The equilibrium Eulerian approach is extended to evolve the particle concentration for varying particle response time and still-fluid settling velocity. Over the entire range of particle parameters …
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Vertical Transport of Sediment from Muddy Buoyant River Plumes in the Presence of Different Modes of Interfacial Instabilities
… than that expected from individual particle settling (i.e., C{W}_{s}). Two potential drivers of enhanced sedimentation are flocculation and interfacial instabilities. We experimentally measured the sediment fluxes from each of these processes using two sets of laboratory experiments that …
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Influence of Flake Morphology on Fluvial Transportation and Site Formation Interpretation
… I also test the influence of flake morphology on settling velocity in relation to transport distance. I conducted these tests using a flume device that creates an idealized set of conditions. The results of these tests show that flake curvature and weight influences transport distance and settling …
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Experiments on the Transformation of Mud Flocs in Turbulent Suspensions
… and how such alterations impact the floc settling velocity, which is one of the most crucial parameters influencing sediment transport modeling. A series of laboratory experiments were conducted to examine the impact of suspended sediment concentration, mixes of clay and silt, and …
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Investigation into the post-mortem transport of benthic foraminifera
… flows.Static water experiments have shown that settling velocities are significantly different between taxa, meaning that assemblages are likely to fractionate according to species during transportation. Settling velocities range from 0.01 to 0.06 ms-1 with larger specimens falling faster than …
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Mechanistic understanding of biogranulation for continuous flow wastewater treatment and organic waste valorization
… its full-scale acceptability. The high settling velocity-based selection pressure has been regarded as the ultimate driving force towards biogranulation in sequential batch reactors (SBRs). In this study, this physical selection pressure was firstly weakened and then eliminated in CFRs …
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Application of Laser-Doppler Velocimetry to the Study of Coagulation and Sedimentation
… suspensions was determined by comparing floc settling velocities. These suspensions are found to be stabilized in basic pH; the addition of sodium dodecyl sulfate (SDS) is insufficient to prevent coagulation of polystyrene suspensions in the presence of an added electrolyte. In a coagulating …
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High-Intensity Shear as a Wet Sludge Disintegration Technology and a Mechanism for Floc Structure Analysis
… iron was found to increase SVI and decrease zone-settling velocity, when added to reactors with mechanically disintegrated sludges. Similar trends were not observed in reactors dosed with ferrous iron. Preliminary results suggest that the ferric/ferrous redox chemistry may serve to enhance floc …
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A methodology for the design of wet detention basins for treatment of highway stormwater runoff
Laboratory-scale settling columns were used to determine the settling velocity distributions of suspended solids to refine a methodology selected by the FHWA in designing wet detention basins for the treatment of highway stormwater runoff. Thirteen runoff samples were collected, over two years, …
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Mechanics of Sandbag Motion In Free-Surface Flow
… the drag force, the added-mass force, the settling velocity, the incipient motion, and the trajectories of different sandbags are studied. Digital Particle Tracking Velocimetry (DPTV) technique is used to estimate different parameters that affect the motion of sandbags. </p> <p> A brief …
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Reduced model for particle laden flow
… of instability, and the fluid properties and velocity are depth averaged to remove the height-dependence. The settling velocity of the particles is hindered by the presence of neighboring particles; this phenomenon is captured by the hindered velocity function that decreases with increasing …
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A computational fluid dynamics model for sediment movement based on the unit stream power approach
… Number (Lui 1957), which represents the shear velocity-settling velocity ratio, is related to the unit stream power and is applied as an alternative incipient motion criterion. The Movability Number, as adapted by Armitage (2001) to account for topography, is utilised for scour hole predictions.
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Structure-Property Relations in Bubble and Solid Particle Suspensions with Moderate Reynolds Numbers
… These properties include the hindered settling velocity and microstructure in solid particle suspensions, the scaling of the velocity variance and hydrodynamic diffusivity in solid particle suspensions, the hindered rise velocity and microstructure in suspensions of monodisperse, …
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An in situ Investigation of Sediment Hydrodynamics for Advancing Seabed Mining Plume Monitoring and Modeling
… to provide real-time measurements of size and settling velocity distributions in the abyssal deep-ocean environment. This instrument was deployed during two pilot deep-sea mining trials at a depth of 4500 meters in the Clarion Clipperton Fracture Zone in the Pacific. Throughout these trials, …
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Modeling methylmercury in Maine's tribal meres
… using four parameters: volumetric outflow rate, settling velocity, burial velocity, and Hg(II) biotic solids partitioning coefficient. The model was evaluated through comparison with measured results from the year 1993. The model results showed that the strictest global Hg regulations will lead …
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Development of Transitional Settling Regimen Parameters to Characterize and Optimize Solids-liquid Separation Performance
Novel settling characteristic metrics were developed based on the fundamental mechanisms of coagulation, flocculation, and settling. The settling metrics determined parameters that are essential in monitoring and optimizing the activated sludge process without the need for expensive or specialized …
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On the structure of flow in an inclined settling column
… was to gain a clearer understanding of the settling mechanism through observation of the flow fields within a particle-free fluid layer which exists at the upper face of the bulk suspension and within the bulk suspension itself. Experimental investigations were carried out using glass beads …
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OIL SPILL CLEANUP BY HYDROPHOBIC SILICA AEROGELS AND SPILLED OIL INTERACTION WITH SUSPENDED SEDIMENTS
… extended to carry out laboratory measurements of settling velocities of sediments, flocs, and Oil-Sediment Aggregations (OSAs). Kaolin was used as the sedimentation source and two different hydrocarbons, diesel and motor oil, were selected as spilled oil. The experimental results indicate that the …
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