Morphological changes in a cuspate sandy beach under persistent high-energy swells: Reñaca Beach (Chile)

2019 ◽  
Vol 417 ◽  
pp. 105988
Author(s):  
R. Agredano ◽  
R. Cienfuegos ◽  
P Catalán ◽  
E. Mignot ◽  
P. Bonneton ◽  
...  
Keyword(s):  
Sandy Beach ◽  
Morphological Changes ◽  
High Energy

Investigation of coastal morphological changes due to river basin characteristics by means of remote sensing and GIS techniques

2003 ◽  
Vol 48 (10) ◽  
pp. 135-142 ◽  
Author(s):  
D.Z. Seker ◽  
C. Goksel ◽  
S. Kabdasli ◽  
N. Musaoglu ◽  
S. Kaya
Keyword(s):  
Black Sea ◽  
Satellite Data ◽  
Satellite Images ◽  
Sandy Beach ◽  
Morphological Changes ◽  
Remote Sensing And Gis ◽  
The Black Sea ◽  
Black Sea Coast ◽  
Delta Formation ◽  
Bathymetric Changes

The Riva River is located on the Anatolian (Asian) side of Istanbul by the Black Sea coast, with a wonderful sandy beach and delta formation which has been selected as the study area. The Riva is the largest river in this region, which flows into the Black Sea and also gives its’ name to the area. The river carries some amount of sediments to the Black Sea. These particles cause considerable changes not only in the bed bathymetry and coastal boundaries of the river but also along the coastline of the Black Sea. The aim of this study is to determine these variations by means of satellite data and GIS. In the study, satellite images dated 1975, 1984, 1992 and 2001 have been used. At the end of the study, the possibility of observing bathymetric changes in front of the coastline by means of satellite data has been investigated and results were evaluated and visualised by means of GIS.

Net sediment transport and morphological change in the swash zone of a high-energy sandy beach from swash event to tidal cycle time scales

2009 ◽  
Vol 267 (1-2) ◽  
pp. 18-35 ◽  
Author(s):  
Gerd Masselink ◽  
Paul Russell ◽  
Ian Turner ◽  
Chris Blenkinsopp
Keyword(s):  
Sediment Transport ◽  
Morphological Change ◽  
Time Scales ◽  
Cycle Time ◽  
Tidal Cycle ◽  
Sandy Beach ◽  
High Energy ◽  
Swash Zone

Shape of the shallow aquifer at the fresh water–sea water interface on a high-energy sandy beach

2016 ◽  
Vol 179 ◽  
pp. 79-89 ◽  
Author(s):  
Damien Buquet ◽  
Colette Sirieix ◽  
Pierre Anschutz ◽  
Philippe Malaurent ◽  
Céline Charbonnier ◽  
...  
Keyword(s):  
Fresh Water ◽  
Sandy Beach ◽  
Sea Water ◽  
High Energy ◽  
Shallow Aquifer ◽  
Water Interface

scholarly journals The properties of high-energy milled pre-alloyed copper powders containing 1 wt.% Al

2007 ◽  
Vol 72 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Viseslava Rajkovic ◽  
Dusan Bozic ◽  
Aleksandar Devecerski
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Morphological Changes ◽  
Milled Powder ◽  
Copper Matrix ◽  
High Energy ◽  
Lattice Parameter ◽  
Good Thermal Stability ◽  
Before And After

The microstructural and morphological changes of inert gas atomized pre-alloyed Cu-1 wt.% Al powders subjected to hith-energy milling were studied. The microhardness of hot-pressed compacts was measured as a function of milling time. The thermal stability during exposure at 800 ?C and the electrical conductivity of compacts were also examined. During the high-energy milling, severe deformation led to refinement of the powder particle grain size (from 550 nm to about 55 nm) and a decrease in the lattice parameter (0.10 %), indicating precipitation of aluminium from the copper matrix. The microhardness of compacts obtained from 5 h-milled powders was 2160 MPa. After exposure at 800?C for 5 h, these compacts still exhibited a high microhardness value (1325 MPa), indicating good thermal stability. The increase of microhardness and good thermal stability is attributed to the small grain size (270 and 390 nm before and after high temperature exposure, respectively). The room temperature electrical conductivity of compacts processed from 5 h-milled powder was 79% IACS. .

scholarly journals The Impact of an Extreme Storm Event on the Barrier Beach of the Lefkada Lagoon, NE Ionian Sea (Greece)

2015 ◽  
Vol 16 (3) ◽  
pp. 562 ◽  
Author(s):  
G. GHIONIS ◽  
S. E. POULOS ◽  
E. VERYKIOU ◽  
A. KARDITSA ◽  
G. ALEXANDRAKIS ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Eastern Mediterranean ◽  
Barometric Pressure ◽  
High Energy ◽  
Storm Event ◽  
Frequency Of Occurrence ◽  
Ionian Sea ◽  
Barrier Beach ◽  
The North ◽  
The Impact

The present investigation examines the characteristics of a high energy storm event, that took place on November 9-11, 2007 in the NE Ionian Sea (eastern Mediterranean), and its impact upon the barrier beach that separates the Lefkada lagoon from the open Ionian Sea. The storm event was caused by NW winds with speeds exceeding 20 m/s (40 knots), which have an annual frequency of occurrence less than 0.015%. This high energy event produced waves with >5 m significant offshore height and 9.5 s period; these waves developed on 10th November during the rapid rise of barometric pressure (~1.4 hPa/hr), which followed the barometric pressure drop from 1020.5 hPa at 06:00 (UTC) of 9th November to 1001.7 hPa at 06:00 h (UTC) of 10th November. Secondary breaking at the shoreline produced wave heights >1.5 m, associated with a surge of >0.4 m and a run-up capability of >2.4 m. The waves managed to overtop the barrier beach (elevations ~2.5 m), lowering the seaward side of the barrier beach by 10-30 cm and causing a coastline retreat of 0.9 to 2.2 m; these morphological changes correspond volumetrically to a sediment loss of approximately 8 m3/m of coastline length from the sub-aerial part of the beach. During the last three decades a significant change in the frequency of occurrence and direction (from S-SW-W to N-NW-NE) of severe storms with wind speeds exceeding 40 knots has been recorded, affecting the sediment transport pattern and contributing to the erosion of the north beaches of Lefkada.

Synthesis and Characterization of Fe-Based Nanocomposites

2019 ◽  
Vol 22 ◽  
pp. 39-47 ◽  
Author(s):  
Fadhéla Otmane ◽  
Salim Triaa ◽  
A. Maali ◽  
B. Rekioua
Keyword(s):  
Epoxy Resin ◽  
Loss Factor ◽  
Morphological Changes ◽  
Structural Parameters ◽  
Xrd Analysis ◽  
High Energy ◽  
Scattering Parameters ◽  
X Ray Diffraction ◽  
Average Grain Size

This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.

scholarly journals The Use of Diamond for Energy Conversion System Applications: A Review

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
K. I. B. Eguiluz ◽  
J. M. Peralta-Hernández ◽  
A. Hernández-Ramírez ◽  
J. L. Guzmán-Mar ◽  
L. Hinojosa-Reyes ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Morphological Changes ◽  
Polymer Electrolyte Membrane ◽  
Pyrolytic Graphite ◽  
Lithium Ion ◽  
Catalytic Efficiency ◽  
Carbon Support ◽  
High Energy ◽  
Boron Doped Diamond ◽  
Carbon Corrosion

Catalytic layers of polymer electrolyte membrane fuel cell (PEMFC) electrodes are usually composed of platinum nanoparticles dispersed on an electron conductive carbon support, which can undergo several degradation processes like dissolution of Pt and carbon corrosion under PEMFC working conditions. In this context, the major advantage of conductive boron-doped diamond (BDD) surfaces is their mechanical and chemical stability. BDD is also considered as a good substrate for studying the intrinsic properties of deposited catalysts, avoiding some problems encountered with other substrates, that is, surface corrosion, oxide formation, or electronic interactions with the deposit. Thus, the first part of this review summarized the surface modification of BDD materials, with emphasis in different techniques, to improve the catalytic efficiency of supported catalysts for PEMFCs. In addition, it is known that graphite carbon or lithium metal alloys used in advanced lithium-ion high-energy batteries suffer morphological changes during the charge-discharge cycling, which in turn results in a very poor cycle life. Thus, the use of diamond materials in these applications was also reviewed, since they have very stable surfaces and exhibits excellent electrochemical properties when compared with other carbon forms like glassy carbon and highly oriented pyrolytic graphite.

EVOLUTION OF THE RADIO OUTFLOW IN LS 5039

2014 ◽  
Vol 28 ◽  
pp. 1460196
Author(s):  
J. MOLDÓN ◽  
M. RIBÓ ◽  
J. M. PAREDES
Keyword(s):  
Gamma Ray ◽  
Morphological Changes ◽  
High Energy ◽  
Physical Processes ◽  
Long Baseline ◽  
Very High Energy ◽  
Energy Gamma ◽  
Orbital Modulation ◽  
5 Ghz ◽  
Very High

Gamma-ray binaries allow us to study physical processes such as particle acceleration up to TeV energies as well as very high energy gamma-ray emission and absorption with changing geometrical configurations on a periodic basis. These sources produce outflows of radio-emitting particles whose structure can be imaged with very long baseline interferometry (VLBI). We observed the gamma-ray binary LS 5039 with the VLBA at 5 GHz during five consecutive days. We present the observed radio morphological changes, which display a periodic orbital modulation. Multifrequency and multiepoch VLBI observations conducted during the last decade confirm that the morphological periodicity is stable on timescales of years. Using a simple model we show that the observed behavior is compatible with the presence of a young non-accreting pulsar with an outflow behind it.

scholarly journals Investigation of Morphological Changes in the Tamsui River Estuary Using an Integrated Coastal and Estuarine Processes Model

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1084 ◽  
Author(s):  
Tung-Chou Hsieh ◽  
Yan Ding ◽  
Keh-Chia Yeh ◽  
Ren-Kai Jhong
Keyword(s):  
Sandy Beach ◽  
Morphological Changes ◽  
River Estuary ◽  
River Mouth ◽  
Physical Processes ◽  
Complex Flow ◽  
Monsoon Period ◽  
Estuarine Processes ◽  
Sediment Flushing ◽  
The Impact

This study is to investigate morphological changes in the Tamsui River Estuary in Taiwan driven by multiple physical processes, such as river flows, tides, waves, and storm surges, and then to study the impacts of sediment flushing operated at the Shihmen reservoir upstream on the river estuary. An integrated coastal and estuarine processes model (CCHE2D-Coast) (Center for Computational Hydroscience and Engineering Two-Dimensional-Coast) was validated by simulating these physical processes in the estuary driven by three historical typhoons in 2008. The site-specifically validated model was then applied to simulate morphological changes in the estuary in response to reservoir sediment flush scenarios from the upstream. For the impact assessment of sediment flushing, a synthetic hydrological event was designed by including a historical typhoon and a typical monsoon. It was found that during the typhoon, the sediments will be mostly deposited in the estuarine river reach of Tamsui and the Wazihwei sandy beach. During the monsoon period, most of the sediments tend to be deposited in the second fishing port of Tamsui, the northern breakwater, and the estuary, while the Wazihwei sandy beach in the river mouth would be scoured by backflow. Simulations of the complex flow fields and morphological changes will facilitate the best practice of sediment management in the coastal and estuarine regions.

scholarly journals Thresholds for morphological changes on an exposed sandy beach as a function of wave height

2010 ◽  
Vol 36 (4) ◽  
pp. 523-532 ◽  
Author(s):  
L. P. Almeida ◽  
Ó. Ferreira ◽  
A. Pacheco
Keyword(s):  
Wave Height ◽  
Sandy Beach ◽  
Morphological Changes
Sign in / Sign up

Export Citation Format

Share Document