4,001 research outputs found
Takayasu's arteritis in children : a review
Takayasu's arteritis is an inflammatory disease of unknown origin involving
aorta, its primary branches and pulmonary artery. This article briefly reviews
the pathology, clinical features and treatment of Takayasu's arteritis, focusing
mainly on the disease in children.peer-reviewe
The caveats in the diagnosis of anomalous origin of left coronary artery from pulmonary artery (ALCAPA)
Anomalous origin of left coronary artery from pulmonary artery (ALCAPA) is an
infrequent, well described, but important anomaly of the coronary origin. Early
diagnosis and prompt surgical treatment of the disease can be life saving. However,
there are several potential sources of error in the seemingly simple stereotype
diagnostic pattern. This article reports a case of ALCAPA and allude to some of the caveats in the diagnosis of this entity.peer-reviewe
Driven weak to strong pinning crossover in partially nanopatterned 2H-NbSe2 single crystal
Investigations into the heterogeneous pinning properties of the vortex state
created by partially nano-patterning single crystals of 2H-NbSe2 reveal an
atypical magnetization response which is significantly drive dependent.
Analysis of the magnetization response shows non-monotonic behavior of the
magnetization relaxation rate with varying magnetic field sweep rate. With all
the patterned pinning centers saturated with vortices, we find that the pinning
force experienced by the vortices continues to increase with increasing drive.
Our studies reveal an unconventional dynamic weak to strong pinning crossover
where the flow of the vortex state appears to be hindered or jammed as it is
driven harder through the interstitial voids in the patterned pinning lattice.Comment: 15 pages with 5 figure
Entropic Multi-Relaxation Models for Simulation of Fluid Turbulence
A recently introduced family of lattice Boltzmann (LB) models (Karlin,
B\"osch, Chikatamarla, Phys. Rev. E, 2014) is studied in detail for
incompressible two-dimensional flows. A framework for developing LB models
based on entropy considerations is laid out extensively. Second order rate of
convergence is numerically confirmed and it is demonstrated that these entropy
based models recover the Navier-Stokes solution in the hydrodynamic limit.
Comparison with the standard Bhatnagar-Gross-Krook (LBGK) and the entropic
lattice Boltzmann method (ELBM) demonstrates the superior stability and
accuracy for several benchmark flows and a range of grid resolutions and
Reynolds numbers. High Reynolds number regimes are investigated through the
simulation of two-dimensional turbulence, particularly for under-resolved
cases. Compared to resolved LBGK simulations, the presented class of LB models
demonstrate excellent performance and capture the turbulence statistics with
good accuracy.Comment: To be published in Proceedings of Discrete Simulation of Fluid
Dynamics DSFD 201
Classical supravalvar aortic stenosis and peripheral pulmonary stenosis
Supravalvar aortic stenosis as well as peripheral pulmonary stenosis are rare forms of congenital
heart disease, which occur, however, relatively frequently in association. This article reports and
discusses the classical findings of SVAS and PPS upon clinical examination and imaging in a sixyear-old
girl that presented with repeated respiratory tract infections and failure to thrive.peer-reviewe
Drops bouncing off macro-textured superhydrophobic surfaces
Recent experiments with droplets impacting a macro-textured superhydrophobic
surfaces revealed new regimes of bouncing with a remarkable reduction of the
contact time. We present here a comprehensive numerical study that reveals the
physics behind these new bouncing regimes and quantify the role played by
various external and internal forces that effect the dynamics of a drop
impacting a complex surface. For the first time, three-dimensional simulations
involving macro-textured surfaces are performed. Aside from demonstrating that
simulations reproduce experiments in a quantitative manner, the study is
focused on analyzing the flow situations beyond current experiments. We show
that the experimentally observed reduction of contact time extends to higher
Weber numbers, and analyze the role played by the texture density. Moreover, we
report a non-linear behavior of the contact time with the increase of the Weber
number for application relevant imperfectly coated textures, and also study the
impact on tilted surfaces in a wide range of Weber numbers. Finally, we present
novel energy analysis techniques that elaborate and quantify the interplay
between the kinetic and surface energy, and the role played by the dissipation
for various Weber numbers
Fluid-Structure Interaction with the Entropic Lattice Boltzmann Method
We propose a novel fluid-structure interaction (FSI) scheme using the
entropic multi-relaxation time lattice Boltzmann (KBC) model for the fluid
domain in combination with a nonlinear finite element solver for the structural
part. We show validity of the proposed scheme for various challenging set-ups
by comparison to literature data. Beyond validation, we extend the KBC model to
multiphase flows and couple it with FEM solver. Robustness and viability of the
entropic multi-relaxation time model for complex FSI applications is shown by
simulations of droplet impact on elastic superhydrophobic surfaces
- …