Velocity Increase of Skyrmion Motion by Constructing Wedge Nanotracks

Hyoid movement in swallowing is biomechanically linked to closure of the laryngeal vestibule for airway protection and to opening of the upper esophageal sphincter. Studies suggest that the range of hyoid movement is highly variable in the healthy population. However, other aspects of hyoid movement such as velocity remain relatively unexplored. In this study, we analyze data from a sample of 20 healthy young participants (10 male) to determine whether hyoid movement distance, duration, velocity, and peak velocity vary systematically with increases in thin liquid bolus volume from 5 to 20 mL. The temporal correspondence between peak hyoid velocity and laryngeal vestibule closure was also examined. The results show that maximum hyoid position and peak velocity increase significantly for 20 mL bolus volumes compared to smaller volumes, and that the timing of peak velocity is closely linked to achieving laryngeal vestibule closure. This suggests that generating hyoid movements with increased power is a strategy for handling larger volumes.

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Interannual surface velocity variations of Pine Island Glacier, West Antarctica

Annals of Glaciology ◽

10.3189/172756403781816239 ◽

2003 ◽

Vol 36 ◽

pp. 205-214 ◽

Cited By ~ 11

Author(s):

Bernhard T. Rabus ◽

Oliver Lang

Keyword(s):

Feature Tracking ◽

Surface Velocity ◽

Synthetic Aperture ◽

Clear Correlation ◽

West Antarctica ◽

Velocity Increase ◽

Grounding Line ◽

Velocity Variations ◽

Independent Confirmation ◽

Observation Period

AbstractThe surface velocity of Pine Island Glacier, West Antarctica, during the period 1992–2000 is measured with synthetic aperture radar feature-tracking techniques. Over the observation period, we find a monotonic acceleration with a spatially uniform amplitude of about 12% of the surface velocity. The acceleration extends > 80 km inland of the grounding line into a zone of prominent arcuate crevasses.The upper limit of these crevasses has migrated up-glacier by 0.2 km a−1 correlated with a velocity increase of similar size in the crevassed zone. On the other hand, there is no clear correlation between the velocity variations and observations of grounding-line migration. These findings suggest ongoing dynamic thinning of Pine Island Glacier, providing independent confirmation of recent interferometric results obtained by Rignot and others (2002).

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Using sub-daily timelapse imagery to investigate the behaviour of Narsap Sermia, SW Greenland.

10.5194/egusphere-egu21-7792 ◽

2021 ◽

Author(s):

Dominik Fahrner ◽

James Lea ◽

Stephen Brough ◽

Jakob Abermann

Keyword(s):

Feature Tracking ◽

Greenland Ice Sheet ◽

Time Lapse ◽

High Temporal Resolution ◽

Time Intervals ◽

Velocity Increase ◽

Tidewater Glaciers ◽

Time Period ◽

Velocity Changes ◽

General Velocity

Greenland&#8217;s tidewater glaciers (TWG) have been retreating since the mid-1990s, contributing to mass loss from the Greenland Ice Sheet and sea level rise. Satellite imagery has been widely used to investigate TWG behaviour and determine the response of TWGs to climate. However, multi-day revisit times make it difficult to determine short-term processes such as calving and shorter-term velocity changes that may condition this.&#160;Here we present velocity, calving and proglacial plume data derived from hourly time-lapse images of Narsap Sermia, SW Greenland for the period July 2017 to June 2020 (n=13,513). Raw images were orthorectified using the&#160;Image GeoRectification And Feature Tracking toolbox&#160;(ImGRAFT; Messerli & Grinsted, 2015) using a smoothed ArcticDEM tile from 2016 (RMSE=44.4px). TWG flow velocities were determined using ImGRAFT feature tracking, with post-processing adjusting for varying time intervals between image acquisitions (if >1 hour) and removing outliers (>x2 mean). The high temporal resolution of the imagery also enabled the manual mapping of proglacial plume sizes from the orthorectified images and the recording of individual calving events by visually comparing images.Results show a total retreat of approximately 700 m, with a general velocity increase from ~15 m/d to ~20 m/d over the investigated time period and highly variable hourly velocities (&#177;12m/d). The number of calving events and plume sizes remain relatively stable from year to year throughout the observation period. However, later in the record plumes appear earlier in the year and the size of calved icebergs increases significantly, which suggests a change in calving behaviour.&#160;

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Effects of Briquettes with Different Crack Structures on Propagation Characteristics of Ultrasonic Waves under Wetting Conditions

10.21203/rs.3.rs-72803/v1 ◽

2020 ◽

Author(s):

Gang Wang ◽

Jinzhou Li ◽

Huaixing Li ◽

Zhiyuan Liu ◽

Yanpei Guo ◽

...

Keyword(s):

Particle Size ◽

Ultrasonic Velocity ◽

Bituminous Coal ◽

Ultrasonic Attenuation ◽

Crack Size ◽

Ultrasonic Waves ◽

Ultrasonic Frequency ◽

Propagation Characteristics ◽

Sample Mass ◽

Velocity Increase

Abstract In order to examine the effect of briquettes with different crack structures on ultrasonic characteristics under different wetting conditions, a series of ultrasonic testing are carried out on briquettes at different wetting heights and the ultrasonic characteristics in these coal samples are explored. The results show that ultrasonic amplitude is positively correlated with the emission voltage, whereas ultrasonic frequency is negatively correlated with the emission voltage. Changes in both are closely related to the particle size and density. The ultrasonic velocity is positively correlated with the wetting degree. Sample mass has the greatest effect on the ultrasonic velocity, followed by particle size, and pressure has the smallest effect. At dry stage, ultrasonic velocity in gas coal is less than that in bituminous coal. The opposite is true in the fully wet state. The influence of crack thickness on ultrasonic velocity gradually increases with the wetting degree increasing. At dry stage, the velocity gradually increases with the crack dip increasing, while as the wetting height increasing, magnitude of velocity increase gradually decreases with the dip increasing. The ultrasonic attenuation in the briquettes reduces with the emission voltage enhancing. The attenuation decreases with sample particle size, crack thickness and crack size decreasing and with sample mass, pressure and crack dip increasing. The ultrasonic attenuation shows a trend of increase before decrease with the wetting height increasing. The attenuation of ultrasonic wave increases with wave velocity increasing for intact samples and shows a trend of increase before decrease for cracked samples.

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Centrifugal acceleration in the magnetotail lobes

Annales Geophysicae ◽

10.5194/angeo-28-569-2010 ◽

2010 ◽

Vol 28 (2) ◽

pp. 569-576 ◽

Cited By ~ 43

Author(s):

H. Nilsson ◽

E. Engwall ◽

A. Eriksson ◽

P. A. Puhl-Quinn ◽

S. Arvelius

Keyword(s):

Cumulative Effect ◽

Field Measurements ◽

Centrifugal Acceleration ◽

Velocity Change ◽

Data Set ◽

Ion Outflow ◽

Velocity Increase ◽

Average Value ◽

Spacecraft Potential ◽

Total Velocity

Abstract. Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

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Noise-based ballistic wave passive seismic monitoring. Part 1: body waves

Geophysical Journal International ◽

10.1093/gji/ggz440 ◽

2020 ◽

Vol 221 (1) ◽

pp. 683-691 ◽

Cited By ~ 5

Author(s):

F Brenguier ◽

R Courbis ◽

A Mordret ◽

X Campman ◽

P Boué ◽

...

Keyword(s):

Seismic Velocity ◽

Noise Source ◽

Seismic Monitoring ◽

Body Waves ◽

P Wave ◽

New Technique ◽

Apparent Velocity ◽

Near Surface ◽

Velocity Increase ◽

Passive Seismic

SUMMARY Unveiling the mechanisms of earthquake and volcanic eruption preparation requires improving our ability to monitor the rock mass response to transient stress perturbations at depth. The standard passive monitoring seismic interferometry technique based on coda waves is robust but recovering accurate and properly localized P- and S-wave velocity temporal anomalies at depth is intrinsically limited by the complexity of scattered, diffracted waves. In order to mitigate this limitation, we propose a complementary, novel, passive seismic monitoring approach based on detecting weak temporal changes of velocities of ballistic waves recovered from seismic noise correlations. This new technique requires dense arrays of seismic sensors in order to circumvent the bias linked to the intrinsic high sensitivity of ballistic waves recovered from noise correlations to changes in the noise source properties. In this work we use a dense network of 417 seismometers in the Groningen area of the Netherlands, one of Europe's largest gas fields. Over the course of 1 month our results show a 1.5 per cent apparent velocity increase of the P wave refracted at the basement of the 700-m-thick sedimentary cover. We interpret this unexpected high value of velocity increase for the refracted wave as being induced by a loading effect associated with rainfall activity and possibly canal drainage at surface. We also observe a 0.25 per cent velocity decrease for the direct P-wave travelling in the near-surface sediments and conclude that it might be partially biased by changes in time in the noise source properties even though it appears to be consistent with complementary results based on ballistic surface waves presented in a companion paper and interpreted as a pore pressure diffusion effect following a strong rainfall episode. The perspective of applying this new technique to detect continuous localized variations of seismic velocity perturbations at a few kilometres depth paves the way for improved in situ earthquake, volcano and producing reservoir monitoring.

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An analytical model for track cycling

Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology ◽

10.1177/1754337111433242 ◽

2012 ◽

Vol 226 (2) ◽

pp. 143-151 ◽

Cited By ~ 2

Author(s):

Richard Lukes ◽

John Hart ◽

Steve Haake

Keyword(s):

Analytical Model ◽

Velocity Increase ◽

Centripetal Forces ◽

Track Cycling ◽

Atmospheric Variables

This paper presents the full derivation of an analytical model for track cycling. The model takes into account the unique aspects of track cycling associated with riding around a velodrome. These include, riding upon a banked track and the resulting tyre scrubbing effects, and the tipping motion of a cyclist passing through a corner with the resulting centripetal forces. Validation was provided using SRMTM power crank data and split times obtained for an elite national cyclist in a 4 km pursuit competition. Results have shown the model to over-predict cyclist performance with a discrepancy of 0.7 s in a finals event and 4.3 s, less than 2% error, in a qualifying race. It is believed this may be attributable to discrepancies in atmospheric variables. However the model has proved capable of predicting the velocity increase, specifically associated with track cycling, as a cyclist passes through a bend. The model is useful for analysis of the physics of track cycling, and can be used to quantitatively predict performance dependent upon bicycle efficiencies, tyre type and venue conditions, in a racing scenario.

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A Study on the Fatigue Characteristics of Al6061-T651 by Shot Peening Velocity

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.326-328.1093 ◽

2006 ◽

Vol 326-328 ◽

pp. 1093-1096 ◽

Cited By ~ 1

Author(s):

Won Jo Park ◽

Sun Chul Huh ◽

Sung Ho Park

Keyword(s):

Residual Stress ◽

Surface Roughness ◽

Fatigue Life ◽

Shot Peening ◽

High Speed ◽

Compressive Residual Stress ◽

Velocity Increase ◽

Fatigue Characteristics ◽

Height Increase ◽

Small Steel

Small steel ball is utilized in Shot peening process. Called “shot ball” are shot in high speed on the surface of metal. When the shot ball hit the surface, it makes plastic deformation and bounce off, that increase the fatigue life by compressive residual stress on surface. In this study, the results of observation on the tensile strength, hardness, surface roughness, compressive residual stress and fatigue life of a shot peened Al6061-T651 were obtained. Experimental results show that arc height increase tremendously by shot velocity. Also, it shows that surface roughness, hardness, compressive residual stress and fatigue life increase as shot velocity increase.

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Vortices' Characteristics to Explain the Flange Height Effects on the Aerodynamic Performances of a Diffuser Augmented Wind Turbine

Journal of Solar Energy Engineering ◽

10.1115/1.4034906 ◽

2016 ◽

Vol 138 (6) ◽

Cited By ~ 3

Author(s):

Rym Chaker ◽

Mouldi Kardous ◽

Mahmoud Chouchen ◽

Fethi Aloui ◽

Sassi Ben Nasrallah

Keyword(s):

Wind Velocity ◽

Particle Image ◽

Flow Direction ◽

Pressure Coefficient ◽

Inlet Section ◽

Wind Tunnel Experiments ◽

Piv Measurements ◽

Velocity Increase ◽

Image Velocimetry ◽

Aerodynamic Performances

Flange height is between the geometric features that contribute efficiently to improve the diffuser aerodynamic performances. Results obtained from wind tunnel experiments, particle image velocimetry (PIV) measurements, and numerical simulations reveal that at the diffuser inlet section, the wind velocity increases as the flange height increases. Nevertheless, there is an optimal ratio (flange height/inlet section diameter, Hopt/Da ≈ 0.15) beyond it, the flange height effect on the velocity increase diminishes. This behavior can be explained by both the positions of the two contra-rotating vortices generated downstream of the diffuser and the pressure coefficient at their centers. Indeed, it was found that, as the flange height increases, the two vortices move away from each other in the flow direction and since the flange height exceeds (Hopt/Da), they became too distant from each other and from the flange. While the pressure coefficients at the vortices' centers increase with (H/Da), attain a maximum when (Hopt/Da) is reached, and then decrease. This suggests that the wind velocity increase depends on the pressure coefficient at the vortices' centers. Therefore, it depends on the vortices' locations which are in turn controlled by the flange height. In practice, this means that the diffuser could be more efficient if equipped with a control system able to hold the vortices too near from the flange.

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