Sentences with phrase «in wave velocity»

Not exact matches

Inspired by a 2012 paper that proposed a correlation between such hotspots and the velocity of seismic waves moving through Earth's interior, UC Santa Barbara geochemist Matthew Jackson teamed with the authors of the original paper — Thorsten Becker of the University of Texas at Austin and Jasper Konter of the University of Hawaii — to show that only the hottest hotspots with the slowest wave velocity draw from the primitive reservoir formed early in the planet's history.

When they compared oceanic hotspots with high levels of He - 3 / 4 to seismic wave velocities, they found that these represent the hottest hotspots, with seismic waves that move more slowly than they do in cooler areas.

The researchers then measured the effect of flavanols on hallmarks of cardiovascular aging, such as arterial stiffness (as measured by pulse wave velocity), blood pressure and flow - mediated vasodilation (the extent to which blood vessels dilate in response to nitric oxide).

Researchers calculated temperatures at the bottom of the crust, which varies in thickness, by measuring the velocity of seismic waves that travel near the interface between the lower crust and uppermost mantle.

«When your arteries are more stiff, you have higher pulse wave velocity, which increases your risk of cardiometabolic disease in the future,» says Raed.

These variables are then used in a machine learning model that determines pulse wave velocity (PWV) and, therefore, arterial stiffness.

There are four types of blast trauma injury: 1) primary injury caused directly by the pressure wave, which can travel through tissue at velocities close to that of sound in water, 2) secondary injury caused by objects put in motion by the blast, 3) tertiary injury caused by an individual thrown into motion by the blast and hitting surrounding objects, and 4) quaternary injury caused by burns, explosion - related injuries, illnesses and diseases not attributed to the other three blast trauma types.

Thus astronomers can interrogate the photons to reveal the basic physical properties, like velocity and density, of gas passing through shock waves in the jets.

The new system, described in the March 5 edition of the journal Nature Communications, combines photons and phonons — electromagnetic energy and sound energy — to conduct sophisticated signal processing tasks by harnessing the properties of lower - velocity acoustic waves.

Nearly a decade ago, Steve Elgar of the Woods Hole Oceanographic Institution (WHOI) set up a series of floating pressure gauges, sonar devices and water velocity meters on a beach in Duck, N.C., in an attempt to determine what changes in wave action bring sand back onshore.

These two figures show the internal waves at Dongsha Island on April 23, 2010, as seen by the radar on TerraSAR - X in its conventional mode of operation (left) and in the experimental new mode that permits direct velocity measurements (right), with the measured surface velocities shown in color.

Variations in its speed are interpreted as velocity waves that evolve with distance, much as ocean waves steepen as they approach a beach

The mineral has a unique layered structure that causes seismic waves to change velocity depending on their direction of travel — just as in the D» layer.

The researchers then visualized the velocity of the two liquids using a technique called Laser Doppler Velocimetry, which detects changes in the frequency of light waves when a laser beam hits them.

Because we can not sample the deep Earth, we must deduce its composition either by looking at the clues hidden in igneous and metamorphic rocks, or by examining proxies for composition and structure such as the three - dimensional variation of the velocity of seismic waves produced by earthquakes and sampled by networks of seismometers on the surface.

As the speed of the object increases to the sonic velocity (the local velocity of sound waves), these sound waves begin to pile up in front of the object.

During a four - year period, the researchers used sensors to measure relative changes in the velocity of seismic waves moving through the volcano over time.

These seismic measurements enabled scientists to visualize these ultralow velocity zones in some regions along the core - mantle boundary, by observing the slowing down of seismic waves passing through them.

«Where these two crustal blocks came into contact, there would have been tremendous deformation that aligned the mineral grains in the rocks and changed the propagation velocities of the seismic waves,» Fischer said.

The researchers estimated that a one percent increase in aortic arch pulse wave velocity (in meters per second) is related to a 0.3 percent increase in subsequent white matter hyperintensity volume (in milliliters) when all other variables are constant.

«Pulse wave velocity from the aortic arch provides functional information about vessel compliance that may help determine a patient's risk for cerebrovascular disease down the road,» said Kevin S. King, M.D., assistant professor of radiology at UT Southwestern Medical Center in Dallas.

«Our results demonstrate that aortic arch pulse wave velocity is a highly significant independent predictor of subsequent white matter hyperintensity volume and provides a distinct contribution — along with systolic blood pressure, hypertension treatment, congestive heart failure and age — in predicting risk for cerebrovascular disease,» Dr. King said.

Dr. King and colleagues set out to evaluate the relationship between aortic arch pulse wave velocity and subsequent cerebral microvascular disease, independent of other cardiovascular risk factors, among 1,270 participants in the multiethnic Dallas Heart Study.

A recent observational study investigating sex differences in target organ damage, in insulin - resistant patients, demonstrated increased vascular and renal damage in women, who had increased intima - media thickness progression, higher numbers of vascular plaques, and reduced pulse wave velocity compared with men (321).

Recently developed, in - situ techniques for direct volume determination, acoustic wave velocity measurements, and x-ray diffraction at HPCAT, along with molecular dynamics simulations, were employed to explore the nature of the unusual and pressure - tunable, compression and elastic properties.

â $ œIt is known that in other populations, increased pulse wave velocity precedes the development of hypertension, â $ Kim says.

Pulse wave velocity is measured by noninvasive devices that track the speed of blood flow by calculating differences between arteries in the neck and the leg.

Another study, which he published with Ezquiaga and others in April 2017, explored the theoretical conditions under which gravity waves could travel at a different velocity than light.

N ~ 2 seen in the spiral arms in M81 and M101 supports the scenario of star formation triggered by cloud - cloud collisions enhanced by spiral density wave, while N ~ 1 derived in giant HII regions in M101 suggests the star formation induced by the Parker instability triggered by high velocity HI gas infall.

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Does the engine propel the vehicle in an even surge of power, like a wave of velocity, or does it shake and jerk and bounce?

Idealized horizontal profiles of vertical velocity (left) and diabatic heating (right) to illustrate how convective heating is asymmetric in an atmospheric wave.

The special identifying feature of Rossby waves is that the phase velocity of each individual wave always has a westward component, but the group velocity can be in any direction.

Long wavelength water waves, in deep water, have a (phase) velocity that increases like the square root of the wavelength so can match earth rotation.

The most obvious signals of lithospheric cooling appear in measurements of heat flow, depth, geoid height, and surface wave velocity and they are best understood in terms of conductive cooling models.

Similarly velocities derived from surface waves reflect lithospheric cooling although there is uncertainty in mapping from velocity to temperature (Ritzwoller et al., 2004).

In contrast to these fast traveling waves, the quasistationary extratropical barotropic free waves with zonal wave numbers 6 to 8 are normally weak, with a magnitude of the meridional wind velocity less than 1.5 — 2.5 m ⋅ s − 1 (25, 34, 35, 39, 40).

Overall, the results of our calculations of the amplitudes of the waves with m = 6, 7, and 8 in the field of the midlatitude meridional velocity at 300 hPa suggest that 12 of the 17 HPA events during May − September of 2012 and 2013 substantially coincided or were preceded by QRA events up to 2 wk earlier (see Fig. 1).

A strong snowmelt in late April / early May and torrential rains in late May / early June could have been caused by the occurrence of persistent quasibarotropic high - amplitude QRA structures with zonal wave numbers m = 6 and m = 7 in the field of the NH midlatitude meridional velocity.

Time series of the observed amplitudes (in meters per second) of zonal wave numbers m = 6 (black), m = 7 (red), and m = 8 (blue) for the 15 - d running means of the meridional wind velocity at 300 hPa averaged over 37.5 ° N − 57.5 ° N for May − September 2012 and 2013, based on daily reanalysis data (41).

This happens in the top 100 microns or less — giving a cool skin effect that is constantly renewed at the velocity of photons in the atmosphere and mixed into the ocean surface at the speed of eddies and waves.

The theory says that you can calculate the velocity of waves in the string from the tension in the string (supplied by the weight hanging from the pulley) and the linear density of the string (ours is 1.00 g / m).

That assertion is consistent with the analysis of wave velocity which shows there must be light elements in the liquid core (roughly 5 %, the liquid is roughly the size of the moon) and theoretical analysis for the liquid core that shows CH4 can «dissolve» in the liquid core and would be extruded when a portion of liquid core solidifies.

Geoff Sharp says: July 29, 2011 at 10:57 pm Looking at the earth velocity graph there appears to be a 10 year period in the perturbation wave.

That 60 year wave in solar velocity is totally created from the gravitation effects from Uranus and Neptune.

Looking at the earth velocity graph there appears to be a 10 year period in the perturbation wave.

Without U / N, velocity and AM would follow a very balanced non perturbed sine wave, there would be no 60 year velocity cycle observed in the peaks and troughs.

Those waves dominate the vertical velocity field in the mixed layer (vortex Rossby waves) and below the first hundred meters (near inertial waves) and they are responsible for the differences in the vertical transport properties under the various forcing fields as quantified by frequency spectra, vertical velocity profiles and vertical dispersion of Lagrangian tracers.

It can detect your pulse wave velocity, which is the speed at which blood circulates in your body and which seemingly provides a glimpse of your heart health.

Dr. Grimes said: «The future will see more use made of sensor technology in smartphones, expanding the range of devices that will not only offer heart rate sensing, but heart rate variability, rhythm detection, and other important measurements like pulse wave velocity, oxygen saturation and respiratory rate.