Search results for "Thermodynamique"
showing 10 items of 10 documents
Information as an essential link between natural science and human science : main focus : the impact of information on the functioning and behaviour …
2016
This thesis aims at considering the information as essential link between the sciences of the nature and the human sciences. It is mainly refered to principles of the natural science, allied in a set of scientific stemming approaches, in particular, theories of the complexity, of chaos, of information, auto-organization, emergences and ecosystems. The laws of the thermodynamics play a central role in this context, where the organization and the negentropy make directly part of the field of information production. There is in particular refered to Law of maximization of entropy Production (or, in other words, of energy dissipation), among which the incidence on the functioning and the behavi…
Thermodynamics, transport phenomena, and electrochemistry of external field-assisted nonthermal food technologies
2017
Interest in the development and adoption of nonthermal technologies is burgeoning within the food and bioprocess industry, the associated research community, and among the consumers. This is evident from not only the success of some innovative nonthermal technologies at industrial scale, but also from the increasing number of publications dealing with these topics, a growing demand for foods processed by nonthermal technologies and use of natural ingredients. A notable feature of the nonthermal technologies such as cold plasma, electrohydrodynamic processing, pulsed electric fields, and ultrasound is the involvement of external fields, either electric or sound. Therefore, it merits to study…
Magnesium silicate hydrate (M-S-H) characterization : temperature, calcium, aluminium and alkali
2017
The various options to store radioactive wastes in deep geological strata considered in France or Switzerland include the use of large volumes of cementitious materials for infrastructure in contact with argillaceous rocks. So-called low-pH binders were developed to minimize disruption to the surrounding rock by the alkaline plume. Studies conducted on the interaction zone between concrete and clay systematically highlighted the formation of magnesium silicate phases including magnesium silicate hydrate (M-S-H) at the interfaces, which can presently be modeled only partially due to incomplete thermodynamic data. The purpose of this study was to characterize these phases in temperature, alum…
Vapor-liquid-solid mechanisms: Challenges for nanosized quantum cluster/dot/wire materials
2006
International audience; The growth mechanism model of a nanoscaled material is a critical step that has to be refined for a better understanding of a nanostructure's dot/wire fabrication. To do so, the growth mechanism will be discussed in this paper and the influence of the size of the metallic nanocluster starting point, referred to later as “size effect,” will be studied. Among many of the so-called size effects, a tremendous decrease of the melting point of the metallic nanocluster changes the physical properties as well as the physical/mechanical interactions inside the growing structure composed of a metallic dot on top of a column. The thermodynamic size effect is related to the bend…
Asymptotic analysis of the form-factors of the quantum spin chains
2020
Since a long-time, the quantum integrable systems have remained an area where modern mathematical methods have given an access to interesting results in the study of physical systems. The exact computations, both numerical and asymptotic, of the correlation function is one of the most important subject of the theory of the quantum integrable models. In this context an approach based on the calculation of form factors has been proved to be a more effective one. In this thesis, we develop a new method based on the algebraic Bethe ansatz is proposed for the computation of the form-factors in thermodynamic limit. It is applied to and described in the context of isotropic XXX Heisenberg chain, w…
A simplified thermal model for the three way catalytic converter
2016
TAP 2016, 21st International Transport and Air Pollution Conference, LYON, FRANCE, 24-/05/2016 - 26/05/2016; A semi empirical model based on thermodynamic behaviour of a three way catalytic converter has been proposed to predict temperature evolution of the converter during the cold start. The model is based on energy and mass balance in the TWC considered as control volume. Parameters of the heat equations are identified separately using a step by step approach. Thermocouples have been inserted along the monolith canals to measure the axial evolution of temperature. Experiments on the engine test bench have been conducted to identify the parameters and to validate the model.
Etude des propriétés de coordination de nouveaux ligands macrocycliques vis-à-vis de cations métalliques en vue de l'utilisation de leurs complexes p…
2011
Noninvasive medical imaging techniques such as single-photon emission computed tomography (SPECT) or positron emission tomography (PET), are valuable tools for the development and validation of new therapeutic molecules. That approach requires the conjugation of a radioactive source emitting either y-rays or positrons with a biological tracer (e.g. DOTATOC). Among the potentially useful radionuclides available, 111In3+ (SPECT), 64Cu2+, and 68Ga3+ (PET) have attracted increasing attention over the last years for medical applications. To minimize the in vivo release of the radioactive cation by transmetalation or transchelation with biological ligands, it is essential to trap selectively the …
Modélisation de phénomènes locaux : vers leur prise en compte dans la simulation de la cinétique d'oxydation d'un métal.
2006
The oxidation of metals is a complex process involving several mechanisms that take place at different length scale (macroscopic and microscopic). In this work, we try to integrate local phenomena (microscopic scale) in macroscopic models, especially to the modelling of the metal oxidation kinetics. The study is divided in two parts ; the first one based on non-equilibrium thermodynamics allows us to obtain the evolution laws of the system metal/oxyde, those were used to modelling oxidation kinetics. The second one is microscopic ; it consists in a study of the thermo-mechanical behaviour of various aluminium surfaces by molecular dynamic and the calculation of their surface energy density.…
Etude expérimentale et modélisation thermodynamique du système CaO-SiO2-(Al2O3)-H2O
2012
The aim of this work is to build a thermodynamic model at 25°C to describe the main hydrates of ordinary Portland cement with or without supplementary cementitious materials (SCM) : calcium hydrosilicates. With high aluminium content, SCM in blended cements modify the nature and the composition of the hydrates of cement paste.The simplified model system CaO-SiO2-H2O was studied by synthesising of C-S-H with identical protocol and analysis. We distinguished, hydration solutions undersaturated and supersaturated from Portlandite.This last system has been extended to CaO-Al2O3-SiO2-H2O system. Then, we determined the most suitable protocol to synthesize pure C-A-S-H.The nanoparticular nature a…
Réseaux de distribution de l’énergie et sobriété énergétique des territoires, les apports d’une approche thermodynamique et métabolique des systèmes …
2017
Dans le contexte de transition énergétique et de crise environnementale actuel, les intérêts des approches territoriales et systémiques de l’énergie semblent aujourd’hui admis. Cependant et malgré les nombreuses avancées dans les domaines technologiques, en matière d’urbanisme et d’aménagement ou bien encore en termes d’approches psycho-sociales et comportementales, les courbes de consommations énergétiques peinent à s’infléchir. Fort de ce constat, nous posons l’hypothèse, sur la base d’éléments théoriques empruntés à la thermodynamique et à la biologie, du rôle potentiel que pourraient jouer les réseaux de distribution énergétique, leurs caractéristiques, leur morphologie et leur dynamiqu…