scholarly journals Nearshore evolution at Noordwijk (NL) in response to nourishments, as inferred from Argus video imagery

Author(s):  
B.G. Ruessink ◽  
R.M. van der Grinten ◽  
L. Vonhögen-Peeters ◽  
G. Ramaekers ◽  
Q.J. Lodder
Keyword(s):  

2002 ◽  
Vol 38 (12) ◽  
pp. 51-1-51-8 ◽  
Author(s):  
A. Allen Bradley ◽  
Anton Kruger ◽  
Ehab A. Meselhe ◽  
Marian V. I. Muste


2021 ◽  
Vol 55 ◽  
pp. 102107
Author(s):  
Natalia Flores Quiroz ◽  
Richard Walls ◽  
Antonio Cicione ◽  
Mark Smith




2010 ◽  
Author(s):  
Alan M. Thomas ◽  
J. Michael Cathcart ◽  
Brian R. Kocher
Keyword(s):  


2012 ◽  
Author(s):  
Mark J. Carlotto ◽  
Mark A. Nebrich


2021 ◽  
Vol 58 (1) ◽  
pp. 3184-3194
Author(s):  
Sara Majlesi

This study evaluated the effect of PETTLEP video imagery onreactive motor skill test (Total RMST time, sprint time, reactive agility time, passing time, and passing accuracy) among 32 Malaysian high school soccer players (mean age of 15.31±1.83) who were randomly assigned into an experimental group (N:16) and a control group (N:16). A pre-test-post-test design was used to evaluate the effect of the intervention on the high schoolplayers' soccer skill performance. The experimental group received 10-minute PETTLEP video imagery trainingbefore their regular soccer training for eight weeks in addition to their regular soccer training, while thecontrol group only attended their regular soccer training. The data analysis revealed a significant effect of video imagery training on players' performance in the experimental group. The results showed that total RMST time, reactive agility time, passing time, and passing accuracy were statistically different within the experimental group F(15, 154.993)= 14.440, p = < .001, Wilks' Λ = .050 and between groups F(5, 56.00)=379.774, p = < .001, Wilks' Λ = .050 after receiving the training, except for the sprint time which was not significant. The findings of this study provide evidence that eight weeks ofPETTLEPvideo imagery training interventioncan significantly improve soccer players' total RMST time, reactive agility time, passing time, and passing accuracy. These findings could be integrated into training programs by coaches and players in order to improve the performance of different soccer skills among high school players.



2021 ◽  
Author(s):  
Andreas Baas

&lt;p&gt;Sand transport by wind over granular beds displays dynamic structure and organisation in the form of streamers (aka &amp;#8216;sand snakes&amp;#8217;) that appear, meander and intertwine, and then dissipate as they are advected downwind. These patterns of saltating grain populations are thought to be initiated and controlled by coherent flow structures in the turbulent boundary layer wind that scrape over the bed surface raking up sand into entrainment. Streamer behaviour is thus fundamental to understanding sand transport dynamics, in particular its strong spatio-temporal variability, and is equally relevant to granular transport in other geophysical flows (fluvial, submarine).&lt;/p&gt;&lt;p&gt;This paper presents findings on streamer dynamics and associated wind turbulence observed in a field experiment on a beach, with measurements from 30Hz video-imagery using Large-Scale Particle Image Velocimetry (LS-PIV), combined with 50Hz wind measurements from 3D sonic anemometry and co-located sand transport rate monitoring using an array of laser particle counters (&amp;#8216;Wenglors&amp;#8217;), all taking place over an area of ~10 m&lt;sup&gt;2&lt;/sup&gt; and over periods of several minutes. The video imagery was used to identify when and where streamers advected past the sonic anemometer and laser sensors so that relationships could be detected between the passage of turbulence structures in the airflow and the length- and time-scales, propagation speeds, and sand transport intensities of associated streamers. The findings form the basis for a phenomenological model of streamer dynamics under turbulent boundary layer flows that predicts the impact of spatio-temporal variability on local measurement of sand transport.&lt;/p&gt;



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