scholarly journals Shoreline Response to a Sandy Nourishment in a Wave-Dominated Coast Using Video Monitoring

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1632 ◽  
Author(s):  
Catarina Jóia Santos ◽  
Umberto Andriolo ◽  
José C. Ferreira
Keyword(s):  
Spatial Analysis ◽  
High Energy ◽  
Video Monitoring ◽  
Preliminary Evaluation ◽  
Coastal Vulnerability ◽  
Wave Forcing ◽  
Recreational Area ◽  
Soft Engineering ◽  
Engineering Intervention ◽  
Automated Procedures

Beach nourishment is a soft engineering intervention that supplies sand to the shore, to increase the beach recreational area and to decrease coastal vulnerability to erosion. This study presents the preliminary evaluation of nourishment works performed at the high-energy wave-dominated Portuguese coast. The shoreline was adopted as a proxy to study beach evolution in response to nourishment and to wave forcing. To achieve this aim, images collected by a video monitoring system were used. A nourishment calendar was drawn up based on video screening, highlighting the different zones and phases where the works took place. Over the six-month monitoring period, a total amount of 25 video-derived shorelines were detected by both manual and automated procedures on video imagery. Nourishment works, realized in summer, enlarged the emerged beach extension by about 90 m on average. During winter, the shoreline retreated about 50 m due to wave forcing. Spatial analysis showed that the northern beach sector was more vulnerable and subject to erosion, as it is the downdrift side of the groin.

scholarly journals ASSESSMENT OF COASTAL VULNERABILITY BASED ON THE USE OF INTEGRATED LOW-COST MONITORING APPROACH AND BEACH MODELLING: TWO ITALIAN STUDY

2020 ◽  
pp. 13
Author(s):  
Renata Archetti ◽  
Maria Gabriella Gaeta ◽  
Fabio Addona ◽  
Leonardo Damiani ◽  
Alessandra Saponieri ◽  
...  
Keyword(s):  
Low Cost ◽  
Integrated Approach ◽  
Video Monitoring ◽  
Monitoring Systems ◽  
Swash Zone ◽  
Coastal Vulnerability ◽  
Italian Study ◽  
Shoreline Evolution ◽  
Low Costs ◽  
Run Up

The use of video-monitoring techniques is significantly increased due to the diffusion of high-resolution cameras at relatively low-costs and they are largely used to estimate the shoreline evolution and wave run-up, as important coastal state indicators to be monitored and predicted for the assessment of flooding and erosion risks. In this work, we present an integrated approach based on the results from the low-cost video monitoring systems and the numerical modeling chain by means of SWAN and XBeach to accurately simulate and predict the swash zone processes.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/nLGNneJzmIU

scholarly journals FIELD MEASUREMENTS AND MODELLING OF NEARSHORE CURRENTS AT A HIGH-ENERGY GEOLOGICALLY-CONSTRAINED BEACH

2020 ◽  
pp. 18
Author(s):  
Arthur Mouragues ◽  
Philippe Bonneton ◽  
Bruno Castelle ◽  
Vincent Marieu
Keyword(s):  
Surf Zone ◽  
Low Frequency ◽  
Field Measurements ◽  
High Energy ◽  
Oblique Wave ◽  
Wave Forcing ◽  
Circulation Patterns ◽  
Wave Conditions ◽  
Nearshore Currents ◽  
Set Up

We present field measurements of nearshore currents at a high-energy mesotidal beach with the presence of a 500-m headland and a submerged reef. Small changes in wave forcing and tide elevation were found to largely impact circulation patterns. In particular, under 4-m oblique wave conditions, our measurements indicate the presence of an intense low-frequency fluctuating deflection rip flowing against the headland and extending well beyond the surf zone. An XBeach model is further set up to hindcast such flow patterns.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/EiqnjBIkWJE

Performance evaluation of neutron detectors incorporating intrinsic Gd using a GEANT4 modeling approach

2011 ◽  
Vol 1341 ◽  
Author(s):  
Abigail A. Bickley ◽  
Christopher Young ◽  
Benjamin Thomas ◽  
John W. McClory ◽  
Peter A. Dowben ◽  
...  
Keyword(s):  
Neutron Capture ◽  
Conversion Electron ◽  
Internal Conversion ◽  
Stable State ◽  
High Energy ◽  
Preliminary Evaluation ◽  
Neutron Detectors ◽  
Internal Conversion Electron ◽  
Modeling Approach ◽  
Type Silicon

ABSTRACTSolid-state neutron detectors from heterostructures that incorporate Gd intrinsically or as a dopant may significantly benefit from the high thermal neutron capture cross section of gadolinium. Semiconducting devices with Gd atoms can act as a neutron capture medium and simultaneously detect the electronic signal that characterizes the interaction. Neutron capture in natural isotopic abundance gadolinium predominantly occurs via the formation of 158mGd, which decays to the ground state through the emission of high-energy gamma rays and an internal conversion electron. Detection of the internal conversion electron and/or the subsequent Auger electron emission provides a distinct and identifiable signature that neutron capture has occurred. Ensuring that the medium responds to these emissions is imperative to maximizing the efficiency and separating out other interactions from the radiation environment. A GEANT4 model, which includes incorporation of the nuclear structure of Gd, has been constructed to simulate the expected device behavior. This model allows the energy deposited from the decay of the meta-stable state to be localized and transported, providing for analysis of various device parameters. Device fabrication has been completed for Gd doped HfO2 on n-type silicon, Gd2O3 on p-type silicon and Gd2O3 on SiC for validation of the code. A preliminary evaluation of neutron detection capabilities of these devices using a GEANT4 modeling approach is presented.

scholarly journals Role of wave forcing, storms and NAO in outer bar dynamics on a high-energy, macro-tidal beach

Geomorphology ◽  
2014 ◽  
Vol 226 ◽  
pp. 76-93 ◽  
Author(s):  
Gerd Masselink ◽  
Martin Austin ◽  
Tim Scott ◽  
Tim Poate ◽  
Paul Russell
Keyword(s):  
High Energy ◽  
Wave Forcing

SU-FF-T-355: Preliminary Evaluation of Optically Stimulated Luminescence (OSL) Dosimetry for Small Field High Energy Photon Beam

2007 ◽  
Vol 34 (6Part13) ◽  
pp. 2483-2483
Author(s):  
M Mirzasadeghi ◽  
G Mardirossian ◽  
E Yukihara ◽  
S Guduru ◽  
S Ahmad
Keyword(s):  
High Energy ◽  
Optically Stimulated Luminescence ◽  
Photon Beam ◽  
Preliminary Evaluation ◽  
Small Field ◽  
High Energy Photon ◽  
Energy Photon

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Observation of Superlattice Dislocations on Cube Planes in Ni3Al

1973 ◽  
Vol 31 ◽  
pp. 174-175 ◽  
Author(s):  
J. M. Oblak ◽  
W. H. Rand
Keyword(s):  
Nearest Neighbor ◽  
Antiphase Boundary ◽  
Nearest Neighbors ◽  
High Energy ◽  
Cross Slip ◽  
Octahedral Plane ◽  
Trapping Mechanism ◽  
Slip Traces

The energy of an a/2 <110> shear antiphase. boundary in the Ll2 expected to be at a minimum on {100} cube planes because here strue ture is there is no violation of nearest-neighbor order. The latter however does involve the disruption of second nearest neighbors. It has been suggested that cross slip of paired a/2 <110> dislocations from octahedral onto cube planes is an important dislocation trapping mechanism in Ni3Al; furthermore, slip traces consistent with cube slip are observed above 920°K.Due to the high energy of the {111} antiphase boundary (> 200 mJ/m2), paired a/2 <110> dislocations are tightly constricted on the octahedral plane and cannot be individually resolved.

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