scholarly journals Strong vorticity fluctuations and antiferromagnetic correlations in axisymmetric fluid equilibria

2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Peter B. Weichman
Keyword(s):  
Antiferromagnetic Correlations ◽  
Strong Vorticity

Intraventricular flow visualization in different heart failure stages with blood pump support in a mock circulatory loop

2021 ◽  
pp. 039139882110214
Author(s):  
Guang-Mao Liu ◽  
Fu-Qing Jiang ◽  
Jiang-Ping Song ◽  
Sheng-Shou Hu
Keyword(s):  
Heart Failure ◽  
Standard Deviation ◽  
Aortic Valve ◽  
Left Ventricle ◽  
Left Ventricular ◽  
Blood Pump ◽  
Blood Damage ◽  
Intraventricular Flow ◽  
Pump Inlet ◽  
Strong Vorticity

The intraventricular blood flow changed by blood pump flow dynamics may correlate with thrombosis and ventricular suction. The flow velocity, distribution of streamlines, vorticity, and standard deviation of velocity inside a left ventricle failing to different extents throughout the cardiac cycle when supported by an axial blood pump were measured by particle image velocimetry (PIV) in this study. The results show slower and static flow velocities existed in the central region of the left ventricle near the mitral valve and aortic valve and that were not sensitive to left ventricular (LV) failure degree or LV pressure. Strong vorticity located near the inner LV wall around the LV apex and the blood pump inlet was not sensitive to LV failure degree or LV pressure. Higher standard deviation of the blood velocity at the blood pump inlet decreased with increasing LV failure degree, whereas the standard deviation of the velocity near the atrium increased with increasing intraventricular pressure. The experimental results demonstrated that the risk of thrombosis inside the failing left ventricle is not related to heart failure degree. The “washout” performance of the strong vorticity near the inner LV wall could reduce the thrombotic potential inside the left ventricle and was not related to heart failure degree. The vorticity near the aortic valve was sensitive to LV failure degree but not to LV pressure. We concluded that the risk of blood damage caused by adverse flow inside the left ventricle decreased with increasing LV pressure.

scholarly journals Local Enhancement of Antiferromagnetic Correlations by Nonmagnetic Impurities

1997 ◽  
Vol 78 (18) ◽  
pp. 3563-3566 ◽  
Author(s):  
George Balster Martins ◽  
Markus Laukamp ◽  
José Riera ◽  
Elbio Dagotto
Keyword(s):  
Local Enhancement ◽  
Nonmagnetic Impurities ◽  
Antiferromagnetic Correlations

scholarly journals Ultrafast dynamics in the presence of antiferromagnetic correlations in electron-doped cuprate La2−xCexCuO4±δ

2017 ◽  
Vol 95 (11) ◽  
Author(s):  
I. M. Vishik ◽  
F. Mahmood ◽  
Z. Alpichshev ◽  
N. Gedik ◽  
J. Higgins ◽  
...  
Keyword(s):  
Ultrafast Dynamics ◽  
Antiferromagnetic Correlations

On the mechanism of high-incidence lift generation for steadily translating low-aspect-ratio wings

2017 ◽  
Vol 813 ◽  
pp. 110-126 ◽  
Author(s):  
Adam C. DeVoria ◽  
Kamran Mohseni
Keyword(s):  
Vortex Pair ◽  
Tip Vortex ◽  
Mean Flow ◽  
Flow Topology ◽  
Trailing Edge ◽  
Negative Contribution ◽  
High Incidence ◽  
The Mean ◽  
Stall Angle ◽  
Strong Vorticity

High-incidence lift generation via flow reattachment is studied. Different reattachment mechanisms are distinguished, with dynamic manoeuvres and tip vortex downwash being separate mechanisms. We focus on the latter mechanism, which is strictly available to finite wings, and isolate it by considering steadily translating wings. The tip vortex downwash provides a smoother merging of the flow at the trailing edge, thus assisting in establishing a Kutta condition there. This decreases the strength/amount of vorticity shed from the trailing edge, and in turn maintains an effective bound circulation resulting in continued lift generation at high angles of attack. Just below the static lift-stall angle of attack, strong vorticity is shed at the trailing edge indicating an increasingly intermittent reattachment/detachment of the instantaneous flow at mid-span. Above this incidence, the trailing-edge shear layer increases in strength/size representing a negative contribution to the lift and leads to stall. Lastly, we show that the mean-flow topology is equivalent to a vortex pair regardless of the particular physical flow configuration.

Transport and Mixing in Kinematic and Dynamically Consistent Flows

2007 ◽  
Vol 64 (10) ◽  
pp. 3640-3651 ◽  
Author(s):  
P. H. Haynes ◽  
D. A. Poet ◽  
E. F. Shuckburgh
Keyword(s):  
Large Range ◽  
Vorticity Field ◽  
Transport Barrier ◽  
Multiple Jets ◽  
Mixing Behavior ◽  
Transport Barriers ◽  
Flow Evolution ◽  
Transport And Mixing ◽  
Dynamical Consistency ◽  
Strong Vorticity

Abstract The interplay between dynamics and transport in two-dimensional flows is examined by comparing the transport and mixing in a kinematic flow in which the velocity field is imposed as a given function of time with that in an analogous dynamically consistent flow in which the advected vorticity field controls the flow evolution. In both cases the variation of the transport and mixing behavior with a parameter ε governing the strength of the time dependence is considered. It is shown that dynamical consistency has the effect of (i) postponing the breaking of a central transport barrier as ε increases and (ii) removing the property of the kinematic flow that, for a large range of ε, a weakly permeable central barrier persists. The first effect is associated with the development of a strong vorticity gradient and the associated jet along the central transport barrier. The second effect is associated with the fact that, in the dynamically consistent flow, the breaking of the central barrier is accompanied by a drastic change in the vorticity field and hence in the structure of the flow. The relation between the vorticity field and transport barriers is further examined using a range of simple kinematic and dynamically consistent models. Implications for formulation of predictive models that represent the interactions between dynamics, transport, and mixing (and might be suggested as a basis for parameterizing eddies in flows that form multiple jets) are discussed.

Two-dimensional antiferromagnetic correlations in an La1.4Sr1.6(Mn0.9Co0.1)2O7 single crystal

2017 ◽  
Vol 124 (5) ◽  
pp. 786-791
Author(s):  
A. A. Bykov ◽  
I. A. Zobkalo ◽  
A. A. Dubrovskii ◽  
O. P. Smirnov ◽  
S. E. Nikitin ◽  
...  
Keyword(s):  
Single Crystal ◽  
Two Dimensional ◽  
Antiferromagnetic Correlations

Magnetic field-induced change of modulated antiferromagnetic correlations for with

2006 ◽  
Vol 385-386 ◽  
pp. 153-155
Author(s):  
Barry L. Winn ◽  
Hiroyuki Kimura ◽  
Dimitri N. Argyriou ◽  
Naofumi Aso ◽  
Kazuma Hirota ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Antiferromagnetic Correlations
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