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This paper concerns an obstacle control problem for an elastic (homogeneous) and isotropic) pseudoplate. The state problem is modelled by a coercive variational inequality, where control variable enters the coefficients of the linear operator. Here, the role of control variable is played by the thickness of the pseudoplate which need not belong to the set of continuous functions. Since in general problems of control in coefficients have no optimal solution, a class of the extended optimal control...
In the present work we investigate the numerical simulation of liquid-vapor phase change
in compressible flows. Each phase is modeled as a compressible fluid equipped with its own
equation of state (EOS). We suppose that inter-phase equilibrium processes in the medium
operate at a short time-scale compared to the other physical phenomena such as convection
or thermal diffusion. This assumption provides an implicit definition of an equilibrium
EOS...
In the present work we investigate the numerical simulation of liquid-vapor phase change
in compressible flows. Each phase is modeled as a compressible fluid equipped with its own
equation of state (EOS). We suppose that inter-phase equilibrium processes in the medium
operate at a short time-scale compared to the other physical phenomena such as convection
or thermal diffusion. This assumption provides an implicit definition of an equilibrium
EOS...
This paper is devoted to solving of dynamic problems in biomechanics that require
detailed study of fast processes. Numerical method of characteristics is used to model the
temporal development of the processes with high accuracy.
Physical analysis of phase transformation of materials consisting from several (both substitutional and interstitial) components, coming from the Onsager extremal thermodynamic principle, leads, from the mathematical point of view, to a system of partial differential equations of evolution type, including certain integral term, with substantial differences in particular phases (, ) and in moving interface of finite thickness (),
in whose center the ideal liquid material behaviour can be detected....
There are very few reference solutions in the literature on non-Boussinesq natural convection flows. We propose here a test case problem which extends the well-known De Vahl Davis differentially heated square cavity problem to the case of large temperature differences for which the Boussinesq approximation is no longer valid. The paper is split in two parts: in this first part, we propose as yet unpublished reference solutions for cases characterized by a non-dimensional temperature difference of...
In the second part of the paper, we compare the solutions produced in the framework of the conference “Mathematical and numerical aspects of low Mach number flows” organized by INRIA and MAB in Porquerolles, June 2004, to the reference solutions described in Part 1. We make some recommendations on how to produce good quality solutions, and list a number of pitfalls to be avoided.
In the second part of the paper, we compare the solutions produced
in the framework of the conference “Mathematical and numerical
aspects of low Mach number flows” organized by INRIA and MAB in
Porquerolles, June 2004, to the reference solutions described in
Part 1. We make some recommendations on how to produce good
quality solutions, and list a number of pitfalls to be avoided.
There are very few reference solutions in the literature on
non-Boussinesq natural convection flows. We propose here a test
case problem which extends the well-known De Vahl Davis
differentially heated square cavity problem to the case of large
temperature differences for which the Boussinesq approximation is
no longer valid. The paper is split in two parts: in this first
part, we propose as yet unpublished reference solutions for cases
characterized by a non-dimensional temperature difference...
Plant growth occurs due to cell proliferation in the meristem. We model the case of
apical meristem specific for branch growth and the case of basal meristem specific for
bulbous plants and grass. In the case of apical growth, our model allows us to describe
the variety of plant forms and lifetimes, endogenous rhythms and apical domination. In the
case of basal growth, the spatial structure, which corresponds to the appearance of
leaves, results...
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 consider an ecosystem in which
spiders may be transported by the wind from vineyards into the
surrounding woods and vice versa. The model takes into account
this tranport phenomenon without building space explicitly into
the governing equations. The equilibria of the dynamical system
are analyzed together with their stability, showing that
bifurcations may occur. Then the effects of indiscriminated
spraying to keep pests under control is also investigated via
suitable simulations.
Two main approaches have been considered for modelling the dynamics of the SIS model on
complex metapopulations, i.e, networks of populations connected by migratory flows whose
configurations are described in terms of the connectivity distribution of nodes (patches)
and the conditional probabilities of connections among classes of nodes sharing the same
degree. In the first approach migration and transmission/recovery process alternate
sequentially,...
Tuberculosis (TB) is the leading cause of death among individuals infected with the
hepatitis B virus (HBV). The study of the joint dynamics of HBV and TB present formidable
mathematical challenges due to the fact that the models of transmission are quite
distinct. We formulate and analyze a deterministic mathematical model which incorporates
of the co-dynamics of hepatitis B and tuberculosis. Two sub-models, namely: HBV-only and
TB-only sub-models...
Bacillus subtilis swarms rapidly over the surface of a synthetic medium
creating remarkable hyperbranched dendritic communities. Models to reproduce such effects
have been proposed under the form of parabolic Partial Differential Equations representing
the dynamics of the active cells (both motile and multiplying), the passive cells
(non-motile and non-growing) and nutrient concentration. We test the numerical behavior of
such models and compare...
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