11 Aprile, 2007 12:30

Seminari di Cultura Matematica

Modelli matematici per scalate ostili nel mercato azionario

E. Barucci, Dip. di Matematica

Aula B.21

2 Aprile, 2007 17:00

Seminari di Cultura Matematica

A continuum model for liquids with vapour bubbles including micro-configurational forces

Maurizio Brocato, CEA (Gif Sur Yvette, Francia)

Dipartimento di Matematica - Politecnico di Milano - Via Bonardi 9 - Milano - Aula Seminari VI piano

abstract

abstract

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

30 Marzo, 2007 11:00

Sezione di Geometria, Algebra e loro applicazioni

Ricostruzione di corpi convessi da sezioni e proiezioni

Aljosa Volcic, Universita della Calabria

Sala Consiglio VII piano

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

30 Marzo, 2007 12:00

Sezione di Geometria, Algebra e loro applicazioni

Ottimizzazione di metodi iterativi a massima verosimiglianza per recupero di risoluzione in PET

Giuseppe Baselli, Dipartimento di Bioingegneria, Politecnico di Mila

Sala Consiglio VII piano

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

30 Marzo, 2007 14:30

Sezione di Geometria, Algebra e loro applicazioni

Tomografia Discreta: problemi, modelli, algoritmi

Elena Barcucci, Universita di Firenze

Sala Consiglio VII piano

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

30 Marzo, 2007 15:30

Sezione di Geometria, Algebra e loro applicazioni

La modellistica fra ricostruzione geometrica e simulazione

Alfio Quarteroni, Politecnico di Milano – EPFL Lausanne

Sala Consiglio VII piano

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

28 Marzo, 2007 12:30

Seminari di Cultura Matematica

Un omaggio al matematico Piero della Francesca

F. Ghione, Univ. di Roma Tor Vergata

Aula B.21

"Bubble dynamics has been widely studied since the very origin of the mechanics of fluids, to deal with problems such as bubbly flows—cavitating or boiling—or sound propagation. Applications span today a broad class of different problems, considering materials such as water, oils, inks, fuels, metals, advanced materials and manufacturing processes, or heat-transfer fluids close to their boiling conditions. Lord Rayleigh’s solution of 1917 to the problem of determining the size of a spherical bubble in an infinite medium where pressure is applied at the boundary, led in the sixties to the generalized Rayleigh- Plesset equation. Continuummodels were then introduced looking heuristically at the liquidwith bubbles as a mixture: the size of bubbles—a continuous field—changes driven by the local value of the pressure field as if pressure were applied on each bubble in Rayleigh’s conditions. The approach proves accurate in the main and versatile in practice. Limits derive nonetheless from the soft boundary condition used to get the local model: any bubble interacts with the rest of the mixture where it is embedded as if the latter were perfectly soft, regardless of the real behaviour of it. The choice entails the uncoupling of the macro from the micromotion

27 Marzo, 2007 14:30

Seminari di Cultura Matematica

Mathematical Oncology: the interplay between biology, medicine and nonlinear sciences

Dott. Alberto D ' Onofrio, Istituto Europeo di Oncologia

Aula Seminari MOX-6° piano Dip. Matematica

abstract

abstract

Due to the vast amount of underlying genetic events and deregulated biochemical networks, the development of tumors and their response to antitumoral treatments are phenomena so complex to be anti-intuitive and to make the outcome of human intervention semi-random.
Currently, the schedulings of therapies are mainly based on empirical basis and on the accumulation of epidemiological inferences.
Nonlinear biophysical models, after being used with great success in ecology, may become a synthetic tool to interpretate the huge amount of experimental results in oncology and also to help medical doctors in planning therapies.
Here some simple models of tumor development and therapies will be illustrated both from a physico-mathematical and biomedical points of view.
In particular, we shall focus on
1) Cell-cell competition
2) Angiogenesis and anti angiogenesis therapies
3) Tumor-Immune system competition and immunotherapies.

26 Marzo, 2007 17:00

Seminario Matematico e Fisico di Milano

Convexity, representation and Liouville theorems

Enzo Mitidieri, Università di Trieste

Dipartimento di Matematica - Università degli Studi - Via Saldini 50 - Milano - Sala di Rappresentanza

abstract

abstract

We point out the strict connection between the convexity property, representation formula of solutions of quasilinear elliptic problems and related Liouville theorems.

21 Marzo, 2007 12:30

Seminari di Cultura Matematica

L’origine delle teorie e l’evoluzione culturale

E. Bellone, Univ. di Milano

Aula B.21

We point out the strict connection between the convexity property, representation formula of solutions of quasilinear elliptic problems and related Liouville theorems.