Monitoring suspended sediment plumes by optical and acoustical methods with application to sand capping

2000 ◽  
Vol 27 (1) ◽  
pp. 125-137 ◽  
Author(s):  
Paul F Hamblin ◽  
David Z Zhu ◽  
Fausto Chiocchio ◽  
Cheng He ◽  
Murray N Charlton
Keyword(s):  
Suspended Sediment ◽  
Bottom Sediments ◽  
Quantitative Estimation ◽  
Three Dimensional ◽  
Pilot Scale ◽  
Optical Measurements ◽  
Acoustic Backscatter ◽  
Density Current ◽  
Dense Network ◽  
Sediment Remediation

There is a need to rapidly survey plumes of suspended sediment and to determine the quantity and transport of disturbed material that might arise from industrial and remedial activities in lakes and harbours. The example of sand capping of contaminated bottom sediments is used to illustrate the methodology. Capping of contaminated bottom sediments is one strategy for immobilizing contaminants. In a pilot-scale project, a 0.34 m thick cap of clean sand was deposited over a one hectare area in Hamilton Harbour. The objective of this study was to determine if in-place sediments could be disturbed by the capping operation. In the first of three approaches, the suspended sediment plumes created during the capping operation were monitored for evidence of suspension of bottom materials with underwater acoustic and optical profilers and other moored instruments. In-lake calibration of the instrumentation was based on the collection of over 300 grab samples. Three-dimensional rendering of a dense network of acoustic backscatter profiles revealed that there was no evidence that bottom sediment was resuspended. The density current flowing downslope close to the bottom caused by the capping material was examined and found too weak to erode bottom sediments. Finally, a quantitative estimation of the amount of sediment suspended in the plumes indicated little evidence for resuspension of in-place sediments. The methodology developed could also be applied to estimate the concentration and quantities of contaminants in sediments suspended by other remedial activities such as dredging. Key words: suspended sediment plumes, underwater acoustics, optical measurements, sediment remediation, harbours, lakes.

Acoustic Inversion Method for Profiling Suspended Sediment Concentration

2014 ◽  
Vol 687-691 ◽  
pp. 3980-3983
Author(s):  
Jun Xi Shi ◽  
Min Zhu ◽  
Yan Bo Wu ◽  
Xing Tao Sun
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Acoustic Backscatter ◽  
Inversion Method ◽  
Dual Frequency ◽  
Frequency Method ◽  
Backscatter Signal ◽  
Size Profile ◽  
Acoustic Inversion

The concentration of suspended sediment is an important parameter for the research of sediment transport. Acoustic backscatter technique has been employed to measure the concentration of suspended sediment recently. It is an inversion problem to measure the concentration from the backscatter signal. In this paper, an improved dual-frequency method is proposed for the concentration inversion of suspension sediment. It is an explicit solution with much lower computational complexity than the commonly used iterative method and with no requirement of known and constant particle size profile compared to the basic dual-frequency method.

scholarly journals Three-Dimensional Trajectory Construction and Observation of Group Behavior of Wild Bats During Cave Emergence

2021 ◽  
Vol 33 (3) ◽  
pp. 556-563
Author(s):  
Emyo Fujioka ◽  
Mika Fukushiro ◽  
Kazusa Ushio ◽  
Kyosuke Kohyama ◽  
Hitoshi Habe ◽  
...  
Keyword(s):  
Quantitative Estimation ◽  
Three Dimensional ◽  
Experimental System ◽  
High Sensitivity ◽  
Group Behavior ◽  
Three Dimensions ◽  
Detection And Tracking ◽  
External Objects ◽  
Behavioral Classification

Echolocating bats perceive the surrounding environment by processing echoes of their ultrasound emissions. Echolocation enables bats to avoid colliding with external objects in complete darkness. In this study, we sought to develop a method for measuring the collective behavior of echolocating bats (Miniopterus fuliginosus) emerging from their roost cave using high-sensitivity stereo-camera recording. First, we developed an experimental system to reconstruct the three-dimensional (3D) flight trajectories of bats emerging from the roost for nightly foraging. Next, we developed a method to automatically track the 3D flight paths of individual bats so that quantitative estimation of the population in proportion to the behavioral classification could be conducted. Because the classification of behavior and the estimation of population size are ecologically important indices, the method established in this study will enable quantitative investigation of how individual bats efficiently leave the roost while avoiding colliding with each other during group movement and how the group behavior of bats changes according to weather and environmental conditions. Such high-precision detection and tracking will contribute to the elucidation of the algorithm of group behavior control in creatures that move in groups together in three dimensions, such as birds.

Active and Passive Responses of Myofibroblasts in Response to Mechanical Stretching in 3D Culture

2008 ◽  
Author(s):  
Adam C. Nathan ◽  
Sheng-Lin Lee ◽  
J. Pablo Marquez ◽  
Tao Ju ◽  
Kenneth M. Pryse ◽  
...  
Keyword(s):  
Mechanical Testing ◽  
Cell Response ◽  
Three Dimensional ◽  
3D Culture ◽  
Confocal Microscope ◽  
Effective Resistance ◽  
Optical Measurements ◽  
Mechanical Stretching ◽  
Stretch Response ◽  
Cells Cultured

The stretch response of myofibroblast cells cultured in a three-dimensional environment was simultaneously measured and observed using a tissue stretching apparatus mounted to a confocal microscope. Optical measurements were used to assess mechanical estimates of cell response obtained through combined mechanical testing and biochemical inhibition. Results show that activated myofibroblasts provide an effective resistance on the order of 100s of kPa. In specific mechanical environments, stretched myofibroblasts release the ECM.

scholarly journals Effects of morphology in controlling propagation of density currents in a reservoir using uncalibrated three-dimensional hydrodynamic modeling

2020 ◽  
Author(s):  
Behnam Zamani ◽  
Manfred Koch ◽  
Ben R. Hodges
Keyword(s):  
Hydrodynamic Model ◽  
Large Scale ◽  
Three Dimensional ◽  
Density Current ◽  
Density Currents ◽  
Large Reservoir ◽  
Bottom Water Temperature ◽  
The Difference ◽  
Basin Morphology ◽  
Southwest Iran

In this study, effects of basin morphology are shown to affect density current hydrodynamics of a large reservoir using a three-dimensional (3D) hydrodynamic model that is validated (but not calibrated) with in situ observational data. The AEM3D hydrodynamic model was applied for 5-month simulations during winter and spring flooding for the Maroon reservoir in southwest Iran, where available observations indicated that large-scale density currents had previously occurred. The model results were validated with near-bottom water temperature measurements that were previously collected at five locations in the reservoir. The Maroon reservoir consists of upper and lower basins that are connected by a deep and narrow canyon. Analyses of simulations show that the canyon strongly affects density current propagation and the resulting differing limnological characteristics of the two basins. The evolution of the Wedderburn Number, Lake Number, and Schmidt stability number are shown to be different in the two basins, and the difference is attributable to the morphological separation by the canyon. Investigation of the background potential energy (BPE) changes along the length of the canyon indicated that a density front passes through the upper section of the canyon but is smoothed into simple filling of the lower basin. The separable dynamics of the basins has implications for the complexity of models needed for representing both water quality and sedimentation.

scholarly journals Agrin regulates CLASP2-mediated capture of microtubules at the neuromuscular junction synaptic membrane

2012 ◽  
Vol 198 (3) ◽  
pp. 421-437 ◽  
Author(s):  
Nadine Schmidt ◽  
Sreya Basu ◽  
Stefan Sladecek ◽  
Sabrina Gatti ◽  
Jeffrey van Haren ◽  
...  
Keyword(s):  
Neuromuscular Junction ◽  
Acetylcholine Receptor ◽  
Three Dimensional ◽  
Postsynaptic Membrane ◽  
Dimensional Structure ◽  
Muscle Membrane ◽  
Synaptic Membrane ◽  
Dense Network ◽  
Phosphatidylinositol 3 Kinase ◽  
Neuronal Regulation

Agrin is the major factor mediating the neuronal regulation of postsynaptic structures at the vertebrate neuromuscular junction, but the details of how it orchestrates this unique three-dimensional structure remain unknown. Here, we show that agrin induces the formation of the dense network of microtubules in the subsynaptic cytoplasm and that this, in turn, regulates acetylcholine receptor insertion into the postsynaptic membrane. Agrin acted in part by locally activating phosphatidylinositol 3-kinase and inactivating GSK3β, which led to the local capturing of dynamic microtubules at agrin-induced acetylcholine receptor (AChR) clusters, mediated to a large extent by the microtubule plus-end tracking proteins CLASP2 and CLIP-170. Indeed, in the absence of CLASP2, microtubule plus ends at the subsynaptic muscle membrane, the density of synaptic AChRs, the size of AChR clusters, and the numbers of subsynaptic muscle nuclei with their selective gene expression programs were all reduced. Thus, the cascade linking agrin to CLASP2-mediated microtubule capturing at the synaptic membrane is essential for the maintenance of a normal neuromuscular phenotype.

Developing the combined magnetic, electric and air flow (KLME) separator for RMSW processing

2018 ◽  
Vol 36 (9) ◽  
pp. 779-787 ◽  
Author(s):  
J Faitli ◽  
B Csőke ◽  
R Romenda ◽  
Z Nagy ◽  
S Németh
Keyword(s):  
Air Flow ◽  
Three Dimensional ◽  
Pilot Scale ◽  
Processing Plant ◽  
Electrically Conductive ◽  
Magnetic Separator ◽  
Two Dimensional Materials ◽  
Physical Processing ◽  
Fundamental Research ◽  
Belt Conveyors

The authors are working on the development of a mechanical–physical processing plant to prepare non-selectively collected residual municipal solid waste (RMSW) in the Zalaegerszeg region of Hungary. A key element of this processing plant is the newly developed KLME separator (the name KLME is the Hungarian abbreviation of ‘combined magnetic, electric and air flow’). This separator is a combination of three widely applied separators, namely a magnetic separator, an eddy current separator and two types of air flow separators designed without the ordinarily necessary cross connecting belt conveyors and feeders. Extensive RMSW and WEEE (waste electrical and electronic equipment) sampling and analyses were carried out in three municipalities to obtain model materials before designing the technology. After fundamental research and laboratory-scale testing, a pilot-scale KLME separator prototype (1.5 ton/h) was made. It has one input stream and five output streams targeted towards five types of products: two-dimensional materials (foils), three-dimensional light materials, magnetic materials, electrically conductive materials and heavy inert materials. Systematic pilot scale testing was carried out and 18 discrete technological setups were tested. The technology as well as the machine were continuously improved and modified based on on-site observations. The best yields and the experience gained are being utilised for the design of an industrial size machine.

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