Search results for "RISA"

About the role of hamiltonian singularities in controlled systems : applications in quantum mechanics and nonlinear optics

2012

This thesis has two goals: the first one is to improve the control techniques in quantum mechanics, and more specifically in NMR, by using the tools of geometric optimal control. The second one is the study of the influence of Hamiltonian singularities in controlled systems. The chapter about optimal control study three classical problems of NMR : the inversion problem, the influence of the radiation damping term, and the steady state technique. Then, we apply the geometric optimal control to the problem of the population transfert in a three levels quantum system to recover the STIRAP scheme.The two next chapters study Hamiltonian singularities. We show that they allow to control the polar…

Motifs de démotorisation dans les aires urbaines françaises : un premier retour sur l'enquête quantitative mode

2019

International audience

Structures optiques dissipatives en cavité laser à fibre

2011

This thesis presents a study of the nonlinear dissipative dynamics of localized of self organized structures in passively mode-locked fiber laser through nonlinear polarization evolution. We reveal the existence of a gradual transition from the quasi-cw to mode locked dynamics in the multi-pulsing regime. We emphasize on the intermediate state, where various new dynamics are observed. We study collective behaviors of dissipative solitons in the presence of a continuous background. One of the complex and attractive dynamics presented is the "soliton rain", which composed of three field components : continuous modes of background, drifting of solitons and condensed phase solitons. This dynami…

Old Principle of Liquid Ion-Impedance Spectrometry (Particularly in Milk) Realised by New Components

2020

Abstract Ion impedance spectrometry enables detection of the concentrations of multiple chemical compositions in a weak solution, usually if only part of a complex signal is used and the frequency is not swept. Prior to the method described in this paper, ion impedance required rather sophisticated electronics to collect the results from an instrument, as well as the electrode polarisation minimising. We elaborated and tested circuitry that uses the newest electronics components for a chemical analysis instrument designed according to a principle patented in Latvia (No. SU-1021440A), year 1981. The newly improved ion impedance spectrometry apparatus is suited for accurate measurement of ion…

Automatic production of three-dimensionnel models by 3D digitization

2012

The manual 3D digitization process is expensive since it requires a highly trained technician who decides about the different views needed to acquire the object model. The quality of the final result strongly depends, in addition to the complexity of the object shape, on the selected viewpoints and thus on the human expertise. Nowadays, the most developed digitization strategies in industry are based on a teaching approach in which a human operator manually determines one set of poses for the ranging device. The main drawback of this methodology is the influence of the operator's expertise. Moreover, this technique does not fulfill the high level requirement of industrial applications which…

La préprofessionnalisation aux métiers de l’enseignement : un dispositif de sécurisation des parcours vers le professorat pour les profils exemplaire…

2022

Study of Biodiversity for Fruit Valorization: the example of Ancient Apple Cultivars (Malus x domestica Borkh.) from Tuscany (Italy)

2010

Persistence of Human Bocavirus 1 in Tonsillar Germinal Centers and Antibody-Dependent Enhancement of Infection

2021

Human bocavirus 1 (HBoV1), a common pediatric respiratory pathogen, can persist in airway secretions for months hampering diagnosis. It also persists in tonsils, providing potential reservoirs for airway shedding, with the exact location, host cell types, and virus activity unknown.

The development of children’s identification: A cross-cultural comparison between Bulgaria, Italy and Ukraine

2009

The study presented here analyses the development of self-categorisation, national, supranational, local and regional identification of Bulgarian, Ukrainian and Italian children and adolescents growing up in Bulgaria, Ukraine and Italy. The sample consisted of 541 children aged 6, 9, 12 and 15 years. It was found that national, supranational, local and regional identifications differ in the three national groups. It is argued that the cognitive-developmental account of the development of national identification is unable to explain the patterns of findings which were obtained. Social representations theory and Social identity theory, however, are able to explain the different patterns of im…

Dynamic nuclear polarisation of biological matter

1986

Polarised targets as used in high energy physics experiments may be of considerable interest in biological structure research using polarized neutrons. So far, this promising method has been facing difficulties in getting reasonable polarization of the target nuclei. We report on a polarized "frozen spin" target which has been prepared from an enzyme dissolved in a mixture of heavy water and deuterated propanediol doped with a completely deuterated paramagnetic radical. Clusters of 700 protons defined by the structure of lysozyme embedded in a fully deuterated matrix were polarized to 75% within an hour by 4 mm microwave irradiation in a magnetic field of 2.5 tesla at a temperature of 0.3 K…