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A distributed-parameter (one-dimensional) anatomically detailed model for the arterial network of the arm is developed in order to carry out hemodynamics simulations. This work focuses on the specific aspects related to the model set-up. In this regard, stringent anatomical and physiological considerations have been pursued in order to construct the arterial topology and to provide a systematic estimation of the involved parameters. The model comprises 108 arterial segments, with 64 main arteries...
Flow cytometric analysis using intracellular dyes such as CFSE is a powerful experimental
tool which can be used in conjunction with mathematical modeling to quantify the dynamic
behavior of a population of lymphocytes. In this survey we begin by providing an overview
of the mathematically relevant aspects of the data collection procedure. We then present
an overview of the large body of mathematical models, along with their assumptions and
uses,...
This contribution reviews the nonlinear
stochastic properties of turbulent velocity and passive scalar
intermittent fluctuations in Eulerian and Lagrangian turbulence.
These properties are illustrated with original data sets of (i)
velocity fluctuations collected in the field and in the
laboratory, and (ii) temperature, salinity and in vivo
fluorescence (a proxy of phytoplankton biomass, i.e. unicelled
vegetals passively advected by turbulence) sampled from highly
turbulent coastal waters. The strength...
We present two-dimensional simulations of chemotactic self-propelled bacteria swimming in
a viscous fluid. Self-propulsion is modelled by a couple of forces of same intensity and
opposite direction applied on the rigid bacterial body and on an associated region in the
fluid representing the flagellar bundle. The method for solving the fluid flow and the
motion of the bacteria is based on a variational formulation written on the whole domain,
strongly...
In this article, we propose an integrated model for oxygen transfer into the blood, coupled with a lumped mechanical model for the ventilation process. Objectives. We aim at investigating oxygen transfer into the blood at rest or exercise. The first task consists in describing nonlinear effects of the oxygen transfer under normal conditions. We also include the possible diffusion limitation in oxygen transfer observed in extreme regimes involving parameters such as alveolar and venous blood oxygen...
In this paper we give a survey on modeling efforts concerning the CVRS. The material we
discuss is organized in accordance with modeling goals and stresses control and transport
issues. We also address basic modeling approaches and discuss some of the challenges for
mathematical modeling methodologies in the context of parameter estimation and model
validation.
Over the past decade or so, there have been a large number of modelling approaches aimed
at elucidating the most important mechanisms affecting the formation of new capillaries
from parent blood vessels — a process known as angiogenesis. Most studies have focussed
upon the way in which capillary sprouts are initiated and migrate in response to
diffusible chemical stimuli supplied by hypoxic stromal cells and leukocytes in the
contexts of solid tumour...
We propose a new numerical scheme based on the finite volumes to simulate the
urethra flow based on hyperbolic balance law. Our approach is based on the Riemann
solver designed for the augmented quasilinear homogeneous formulation. The scheme has general semidiscrete wave–propagation form and can be extended to arbitrary high order accuracy. The first goal is to construct the scheme, which is well balanced, i.e. maintains not only some special steady states but all steady states which can occur....
We propose a model for a medical device, called a stent, designed for
the treatment of cerebral aneurysms. The stent consists of a grid,
immersed in the blood flow and located at the inlet of the aneurysm.
It aims at promoting a clot within the aneurysm. The blood flow is
modelled by the incompressible Navier-Stokes equations and the stent
by a dissipative surface term. We propose a stabilized finite element
method for this model and we analyse its convergence in the case of
the Stokes...
Experimental evidence collected over the years shows that blood exhibits non-Newtonian characteristics such as shear-thinning, viscoelasticity, yield stress and thixotropic behaviour. Under certain conditions these characteristics become relevant and must be taken into consideration when modelling blood flow. In this work we deal with incompressible generalized Newtonian fluids, that account for the non-constant viscosity of blood, and present a new numerical method to handle fluid-rigid body interaction...
We consider the coupling between three-dimensional
(3D) and one-dimensional (1D) fluid-structure interaction
(FSI) models describing blood flow inside compliant vessels.
The 1D model is a hyperbolic
system of partial differential equations.
The 3D model consists of the Navier-Stokes equations
for incompressible Newtonian fluids coupled with
a model for the vessel wall dynamics. A non standard formulation
for the Navier-Stokes equations is adopted to
have suitable boundary conditions for the...
Various particle methods are widely used to model dynamics of complex media. In this work
molecular dynamics and dissipative particles dynamics are applied to model blood flows
composed of plasma and erythrocytes. The properties of the homogeneous particle fluid are
studied. Capillary flows with erythrocytes are investigated.
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