Search results for "Cinétique"
showing 10 items of 13 documents
Valorization of rapeseed meal by solid state fermentation for an application in animal nutrition
2017
Solid state fermentation (SSF) is a biotechnological process particularly well adapted to the treatment of vegetable biomass. This technology adjustable to industrial scale, is adapted to current challenges in animal nutrition by developing fermented products in order to improve the quality of raw materials from a nutritional and functional point of view. The work presented in this thesis considers these issues using rapeseed meal from the oil crushing industry.A first screening study highlighted several fungal strains based on their growth performance and protein enrichment (total and digestible) of the substrate. Levels similar to those of soybean meal, the main protein source in animal n…
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.…
Influence de l'atmosphère gazeuse sur la cinétique de formation du titanate de baryum par réaction solide-solide
1986
International audience; Les études consacrées à la synthèse, par réaction solide-solide, du titanate de baryum (BaTiO3) ont montré l'importance des propriétés physicochimiques des solides initiaux (BaCO3 et TiO2) sur les propriétés du titanate obtenu. Lors de l'élaboration de céramiques diélectriques, il est en effet nécessaire d'éviter la formation de phases intermédiaires (Ba2TiO4, BaTi4O9, ...) qui nuisent à leurs propriétés diélectriques. La présence de ces phases peut être liée à une maîtrise imparfaite des nombreux paramètres influant sur la cinétique de la réaction. Le rôle de deux de ces paramètres : les traitements mécaniques et la nature de l'atmosphère gazeuse, fait l'objet de ce…
Multisensory integration as a strategy to compensate for sodium and fat reduction in food
2012
Multisensory integration as a strategy to compensate for sodium and fat reduction in food. Forum Jeunes chercheurs
Study of nucleation-growth processes of ettringite, alone or in a tricalcium aluminate/calcium sulfate system
2019
Ettringite Ca6Al2(SO4)3(OH)12.26H2O is one of the main hydration products of cements but despite the importance of this compound for cement chemistry, laws governing its precipitation processes have been poorly studied. This PhD thesis was entirely focused on the study of ettringite and on its nucleation-growth mechanisms.Ettringite precipitation was first studied alone from supersaturated ionic solutions. Experiments were designed in order to study separately processes of nucleation and growth. The Classical Theory of Nucleation was applied and allowed the determination of the interfacial energy of ettringite. A global description of ettringite precipitation process has been suggested. It …
Altérations neuromusculaires induites par des exercices excentriques et concentriques fatigants : emphase sur le pédalage des membres inférieurs
2021
The influence of dynamic contraction type (concentric or eccentric) on performance fatigability and associated neuromuscular alterations is partly unknown. Contraction type interacts with other exercise features such as intensity (maximal; submaximal) or modality (single-joint; locomotor). Thus, we compared eccentric with concentric exercises of similar characteristics across three experimental studies. We showed that, for the completion of a given amount of mechanical work, both contraction types impaired maximal voluntary isometric torque similarly. However, neuromuscular impairments depended on exercise features. In study 1, maximal single-joint eccentric contractions affected neural but…
Etude de la morphologie de l'interface reactive de dissolution en utilisant le concept de géométrie fractale
1995
National audience
Study of the hydrolysis of lithium hydride
2015
The hydrolysis of LiH at room temperature and under low water vapor pressure (PH2O < 10 hPa) is investigated by thermogravimetry and FTIR spectroscopy with low sample mass. Then, to be closer to industrial conditions, hydrolysis of LiH is studied by manometry either in closed (adjustable PH2O) or open (constant PH2O) system using larger amounts of sample and heavy water. Products of the reaction are characterized by X-ray diffraction and FTIR spectroscopy. The first set of experiments show that the mechanism of hydrolysis starts with the formation of lithium oxide Li2O. Then, when the oxide layer is sufficiently thick, the hydrolysis reaction is followed by the formation of lithium hydroxid…
New theoretical and experimental concepts for frequency generation in optical fibers: modulation instability, pulsed Raman Laser and kinetic approach…
2009
Following a brief introduction to optical fibers, we combine the effect of modulational instability and Raman self-frequency shift to generate a frequency combs with a spectral width higher than 100 nm and a central frequency shifted towards higher wavelengths. Then, the stimulated Raman effect is used in a ring cavity coupled with nonlinear polarization rotation and polarization filtering. A pulsed regime is obtained at the wavelength of the first Stokes emission and presents a rich zoology of experimental dynamic pulsed regimes. A second main line of this manuscript considers the incoherent regime of supercontinuum generation. We show that under certain conditions, the spectral broadening…
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 …