scholarly journals Sediment mass movement of a particle-laden turbidity current based on ultrasound velocity profiling and the distribution of sediment concentration

2018 ◽  
Vol 477 (1) ◽  
pp. 427-437 ◽  
Author(s):  
Shun Nomura ◽  
Jumpei Hitomi ◽  
Giovanni De Cesare ◽  
Yasushi Takeda ◽  
Yuzuru Yamamoto ◽  
...  
Keyword(s):  
Concentration Distribution ◽  
Light Attenuation ◽  
Mass Movement ◽  
Video Recording ◽  
Sediment Concentration ◽  
Turbidity Current ◽  
The Body ◽  
Doppler Velocity ◽  
Wall Region ◽  
Mass Transport Process

AbstractParticle-laden flows or turbidity currents along the seafloor are important to the formation and erosion of submarine topography. To understand the mass-transport process, flume tests were carried out with a continuous supply of quartz-laden suspension. The vertical and horizontal velocities were extracted by two pairs of ultrasound Doppler velocity profilers installed at different angles with respect to the bed-normal direction. Due to the head intrusion into the ambient water, the sediment in the suspension was continuously lifted up and mixed, leaving lobes and clefts. The velocity-maximum layer acted as the main sediment conveyor and divided the body into wall and jet regions. The concentration distribution was also quantified based on the relationship between the fluid density and the intensity of light attenuation obtained using a video recording. An area of high sediment concentration was observed just behind the head frontal area. Analysis of the velocity and concentration distribution demonstrated that sediment in the turbidity current was transported mainly by head movement and that continuous sedimentation took place in the wall region. The results indicate that a turbidity current proceeds while maintaining an ordered inner dynamic structure.

Analysis on Sediment Environment and Waterway Siltation Characteristics of Panjin Port

2012 ◽  
Vol 212-213 ◽  
pp. 205-210 ◽  
Author(s):  
Xiao Xiang Feng ◽  
Ming Zhang ◽  
Zhe Liu
Keyword(s):  
Concentration Distribution ◽  
Sediment Concentration ◽  
Silty Sand ◽  
Deposit Characteristics

Sediment environment forms nature of the coast, and determines siltation characteristics of port and waterway. Based on definition for existing coast type, sediment environment of Panjin Port is studied by deposit characteristics, sediment concentration distribution, deposit from the tested pit and other aspects. The results show that, the Panjin Port is silty-sand coast. The beach had been stable and shallow beach is the main source of sediments. Although there has the possibility of sudden sedimentation from Geligangzi beach to 10m bathymetric line, siltation materials in the waterway is diggable.

Vertical Sediment Concentration Distribution in High-Concentrated Flows: An Analytical Solution Using Homotopy Analysis Method

2018 ◽  
Vol 70 (3) ◽  
pp. 367 ◽  
Author(s):  
Manotosh Kumbhakar ◽  
Jitraj Saha ◽  
Koeli Ghoshal ◽  
Jitendra Kumar ◽  
Vijay P. Singh
Keyword(s):  
Analytical Solution ◽  
Homotopy Analysis Method ◽  
Concentration Distribution ◽  
Sediment Concentration ◽  
Analysis Method ◽  
Homotopy Analysis

Effects of tributary inflow and sediment input on reservoir turbidity current formation and evolution

2021 ◽  
Author(s):  
Yining Sun ◽  
Ji Li ◽  
Zhixian Cao ◽  
Alistair G.L. Borthwick
Keyword(s):  
Yellow River ◽  
Sediment Concentration ◽  
Turbidity Current ◽  
Turbidity Currents ◽  
Front Speed ◽  
Sediment Input ◽  
Formation And Evolution ◽  
Maximum Utilization

<p>For reservoirs built on a hyper-concentrated river, tributary inflow and sediment input may affect the formation and evolution of reservoir turbidity current, and accordingly bed morphology. However, the understanding of tributary effects on reservoir turbidity currents has remained poor. Here a series of laboratory-scale reservoir turbidity currents are investigated using a coupled 2D double layer-averaged shallow water hydro-sediment-morphodynamic model. It is shown that the tributary location may lead to distinctive effects on reservoir turbidity current. Clear-water flow from the tributary may cause the stable plunge point to migrate upstream, and reduce its front speed. Sediment-laden inflow from the tributary may increase the discharge, sediment concentration, and front speed of the turbidity current, and also cause the plunge point to migrate downstream when the tributary is located upstream of the plunge point. In contrast, if the tributary is located downstream of the plunge point, sediment-laden flow from the tributary causes the stable plunge point to migrate upstream, and while the tributary effects on discharge, sediment concentration, and front speed of the turbidity current are minor. A case study is presented as of the Guxian Reservoir (under planning) on the middle Yellow River, China. The present finding highlights the significance of tributary inflow and sediment input in the formation and propagation of reservoir turbidity current and also riverbed deformation. Appropriate account of tributary effects is warranted for long-term maintenance of reservoir capacity and maximum utilization of the reservoir.</p>

scholarly journals LONGEVITY OVER THE COUNTER: INVESTIGATING THE EFFECTS OF COMMON DIETARY SUPPLEMENTS ON AGING

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S102-S103
Author(s):  
Ben Blue ◽  
Elena Vayndorf ◽  
Matt Kaeberlein
Keyword(s):  
Body Wall ◽  
Video Recording ◽  
The Body ◽  
Limiting Factor ◽  
Time Of Death ◽  
Image Capture ◽  
Over The Counter ◽  
C Elegans ◽  
Short Lifespan ◽  
Age Related

Abstract C. elegans has been a workhorse within the field of aging biology for several decades due to its short lifespan, easy culturing, and robust genetic tools. However, the limiting factor in using C. elegans has been that throughput was constrained by the time and effort needed to manually check the worms for signs of life during longitudinal studies. By using the WormBot, a robotic image capture platform, we are able to successfully screen a wide array of compounds for their effects upon C. elegans lifespan. A single WormBot can monitor 144 individual experiments simultaneously and allows for accurate time of death calls. Here we present data generated with the WormBot that includes a screen of compounds from a wide array of natural and synthetic products that are often available as over-the-counter supplements. In order to better examine the effects of these widely-used compounds upon the aging process and an age-associated disease we examined longevity in a wildtype strain of C. elegans as well as an engineered strain that expresses human Aβ protein in the body wall muscle. The age-related pathogenesis of the Aβ-expressing strain is a progressive paralysis that can be halted with treatment of known effectors of Alzheimer’s disease. As such, we screened our battery of compounds with this strain to determine which compounds have a significant affect on delaying Aβ-associated paralysis. Lastly, using the WormBot’s ability to capture video recording, we examine how each compound affects mobility as animals age.

scholarly journals A Novel Neural Network-Based SINS/DVL Integrated Navigation Approach to Deal with DVL Malfunction for Underwater Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wanli Li ◽  
Mingjian Chen ◽  
Chao Zhang ◽  
Lundong Zhang ◽  
Rui Chen
Keyword(s):  
Neural Network ◽  
Autonomous Navigation ◽  
Underwater Vehicles ◽  
The Body ◽  
Doppler Velocity ◽  
Integrated Navigation ◽  
Body Frame ◽  
Short Term ◽  
The Neural Network ◽  
Nonlinear Autoregressive

A navigation grade Strapdown Inertial Navigation System (SINS) combined with a Doppler Velocity Log (DVL) is widely used for autonomous navigation of underwater vehicles. Whether the DVL is able to provide continuous velocity measurements is of crucial importance to the integrated navigation precision. Considering that the DVL may fail during the missions, a novel neural network-based SINS/DVL integrated navigation approach is proposed. The nonlinear autoregressive exogenous (NARX) neural network, which is able to provide reliable predictions, is employed. While the DVL is available, the neural network is trained by the body frame velocity and its increment from the SINS and the DVL measurements. Once the DVL fails, the well trained network is able to forecast the velocity which can be used for the subsequent navigation. From the experimental results, it is clearly shown that the neural network is able to provide reliable velocity predictions for about 200 s–300 s during DVL malfunction and hence maintain the short-term accuracy of the integrated navigation.

Implantation of a Thoracic Spinal Cord Stimulator Paddle Electrode and Generator Under General Anesthesia With Intraoperative Neuromonitoring: 2-Dimensional Operative Video

2018 ◽  
Vol 16 (6) ◽  
pp. E169-E169 ◽  
Author(s):  
Lauren E Stone ◽  
Steven M Falowski
Keyword(s):  
Spinal Cord ◽  
Video Recording ◽  
Intraoperative Neuromonitoring ◽  
The Body ◽  
Spinal Cord Stimulator ◽  
Thoracic Spinal Cord ◽  
Thoracic Spinal ◽  
Lead Placement ◽  
Patient Consent ◽  
Spinal Flexibility

Abstract Spinal cord stimulation is a well-established and effective therapy in the treatment of pain. Proper patient selection and accurate lead placement are paramount in its success. Placement is a multifaceted process requiring proper paddle placement, a well thought out generator placement and appropriate means to limit complications and enhance success. Several intraoperative techniques maximize outcomes, including removal of the superior portion of the inferior level's spinous process for paddle access into the epidural space, generator pocket placement in a location that limits patient discomfort, a strain relief loop at the thoracic incision to prevent lead fractures and allow for full spinal flexibility, generator placement parallel to the body and secured in the pocket to prevent unwanted movement, and intraoperative neuromonitoring for patient comfort and more accurate lead placement compared to X-ray alone or awake placement. This case demonstrates these key elements of intraoperative technique in a candidate with the most common indication for spinal cord stimulator placement–postlaminectomy syndrome–underscoring the ease and viability of this procedure in the appropriate patient population in a means that reduces future complications and adverse events while maximizing success.  Full patient consent for video-recording and subsequent use for research purposes was attained. All patient identifiers have been removed for the purpose of patient confidentiality.

Dramaturgy of the Body: Marcello Moretti's Construction of Arlecchino at the Piccolo Teatro of Milan

2018 ◽  
Vol 34 (2) ◽  
pp. 130-144
Author(s):  
Gabrielle Houle
Keyword(s):  
Oral History ◽  
Life Experiences ◽  
Video Recording ◽  
Assistant Professor ◽  
The Body ◽  
Historical Research ◽  
Commedia Dell'arte ◽  
Canadian Universities ◽  
History Of ◽  
The University

In this article Gabrielle Houle examines the dramaturgical process that actor Marcello Moretti applied to his creation of Arlecchino's body in Giorgio Strehler's globally acclaimed productions of The Servant of Two Masters at the Piccolo Teatro of Milan between 1947 and 1960. She provides a critical analysis of Moretti's interdisciplinary and trans-historical research and creative process, including his study of iconographic representations of the commedia dell’arte, his observation of farmers in Padua in the mid-twentieth century, and the connections he made between his life experiences and his understanding of Arlecchino. She then examines Moretti's acting style, signature postures, and footwork, both as the international press described them and as she observed them in a video recording and in photographs of the productions. The article, based on extensive archival research at the Piccolo Teatro and on interviews with artists who knew both Moretti and Strehler, concludes with a discussion of Moretti's legacy within and beyond Italy. Gabrielle Houle is a theatre scholar, educator, and artist specializing in the recent staging history of the commedia dell’arte, contemporary mask-making practices, and masked performance. She has taught in several Canadian universities, and is a member of the Centre for Oral History and Tradition at the University of Lethbridge, where she is also an Adjunct Assistant Professor.

Structural features of turbulent flow over smooth and rough boundaries

1971 ◽  
Vol 50 (2) ◽  
pp. 233-255 ◽  
Author(s):  
A. J. Grass
Keyword(s):  
Boundary Layer ◽  
Surface Roughness ◽  
Reynolds Stress ◽  
Quantitative Description ◽  
Structural Features ◽  
The Body ◽  
Wall Region ◽  
Turbulence Structure ◽  
Turbulence Production ◽  
Conditional Averaging

An experimental study of boundary-layer turbulence in a free surface channel flow is described. Attention is concentrated on the effects of different surface roughness conditions on the turbulence structure in the boundary region. Hydrogen bubble flow tracers and medium high-speed motion photography were used to obtain an instantaneous visual and quantitative description of the flow field. In particular it proved possible to record instantaneous longitudinal and vertical velocity profiles from which distributions of the instantaneous Reynolds stress contribution were computed.Two well-defined intermittent features of the flow structure were visually identified close to the boundary. These consisted of fluid ejection phases, previously reported by Kline et al. (1967) for smooth boundary flow, and fluid inrush phases. Conditional averaging of the instantaneous velocity data yielded quantitative confirmation that ejection phases corresponded with ejection of low momentum fluid outwards from the boundary whilst inrush phases were associated with the transport of high momentum fluid inwards towards the boundary. Inrush and ejection events were present irrespective of the surface roughness condition.Conditional averaging also indicated that both inrush and ejection sequences correlate with an extremely high contribution to Reynolds stress and hence turbulence production close to the boundary. Indeed the present results, taken with those from previous studies, suggest that turbulence production is dominated by the joint contribution from the inrush and ejection events. It is emphasized that these structural features are intermittent, forming important linked elements of a randomly repeating cycle of wall-region turbulence production which is apparently driven by some violent three-dimensional instability mechanism.Whilst the most coherent effects of the observed inrush phases appear to be mainly confined to a region close to the boundary, the influence of the ejection phases is far more extensive. The ejected low momentum fluid elements, drawn from the viscous sublayer and from between the interstices of the roughness elements, travel outwards from the boundary into the body of the flow and give rise to very large positive contributions to Reynolds stress at points remote from the boundary. This effect is sufficiently strong to prompt the suggestion that the ejection process could represent a universal and dominant mode of momentum transport outside the immediate wall region and possibly extending across the entire thickness of the boundary layer.A structural model based on the present observations is seen to exhibit consistency with many commonly visualized features and recorded average properties of turbulent boundary-layer flows in general.

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