Tesi sul tema "Ultra haute résolution"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-32 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Ultra haute résolution".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
Zumsteg, Cedric. "Spectroscopie ultra haute résolution d'un ion unique de calcium". Phd thesis, Université de Provence - Aix-Marseille I, 2010. http://tel.archives-ouvertes.fr/tel-00507487.
Zumsteg, Cédric. "Spectroscopie ultra haute résolution d’un ion unique de calcium". Aix-Marseille 1, 2010. https://tel.archives-ouvertes.fr/tel-00507487.
Lagoutte, Angélique. "Cristallographie à ultra haute résolution et analyse expérimentale des énergies d'interaction intermoléculaires". Nancy 1, 2007. http://docnum.univ-lorraine.fr/public/SCD_T_2007_0143_LAGOUTTE.pdf.
The electrostatic properties are of major importance in many biological processes (catalysis, molecular recognition, ligand affinity) and in the crystal packing formation of small molecules. The calculation of the electrostatic interaction energy between a protein and a ligand allows the analysis of the structure/function relationships of the protein. A precise description of the electron density of the studied molecules is then necessary. This can be obtained by using an aspherical atom model, like the multipolar model of Hansen & Coppens, refined from X-ray diffraction data at ultra high resolution. In order to calculate the electrostatic contribution of the interaction energy, advanced methods of numerical integration were implemented in the VMoPro software. To analyze the various electrostatic properties, the program was modernized and developed: 2D and 3D grids calculations, atom selection, Fourier synthesis, Laplacian and critical point analysis, electrostatic potential, van der Waals energy and electrostatic interaction energy. Tests of precision were made to validate the integration method and to carry out the first applications in a urea crystal. The methodology is currently applied to the calculation of the interactions between the human aldose reductase protein and the Fidarestat ligand. The experimental charge densities of two nucleic acids bases (ribonucleotide thymidine and cytosine) were analyzed to extend the multipolar atom databank describing the electron density of biomolecules
Guernet, François. "Spectroscopie d'absorption saturée à ultra haute résolution par sélection de molécules lentes et détection hétérodyne". Paris 13, 1993. http://www.theses.fr/1993PA132030.
Favier, Maxime. "Horloge à réseau optique de mercure : spectroscopie haute-résolution et comparaison d'étalons de fréquence ultra-précis". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066598/document.
This thesis presents the development of a high-accuracy optical frequency standard based on neutral mercury 199Hg atoms trapped in an optical lattice.I will present the experimental setup and the improvements that were made during this thesis, which have allowed us to perform spectroscopy on the doubly forbidden 1S0 - 3P0 mercury clock transition with Hz level resolution. With such a resolution, we have been able to conduct an in-depth study of the physical effects affecting the clock transition. This study represents a factor 60 in accuracy on the knowledge of the clock transitions frequency, pushing the accuracy below the current realization of the si second by the best cesium atomic fountains. Finally, i will present the results of several comparison campaigns between the mercury clock and other state-of-the-art frequency standards, both in the optical and in the microwave domain
Shao, Kai. "Nouvelles méthodes d'imagerie haute résolution pour l'analyse des composants nanoélectroniques". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14596/document.
Using the nonlinear interaction between ultra-short laser pulses (λ ~ 0.8μm to1.3μm) and silicon, with multi-photon absorption or optical harmonic generation, to achieve photoelectric stimulation and testing. Development of imaging methods for static and dynamic failure analysis techniques using femtosecond laser (TOBIC, 2pLADA) on integrated circuits
Peres, Jean Claude. "Etude de la faisabilité d'une gamma-caméra équipée d'un détecteur au germanium ultra-pur et d'un collimateur haute résolution". Toulouse 3, 1990. http://www.theses.fr/1990TOU30039.
Aabbaoui, Hassan El. "Contribution à l'étude et à la réalisation d'un numériseur ultra large bande à haute résolution en filière TBH InP". Lille 1, 2007. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2007/50376-2007-87.pdf.
Ahmed, Maqsood. "Ultra high resolution crystallography of small molecules and proteins". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0024/document.
Ultra high resolution X-ray crystallography allows for analyzing the charge distribution in the molecules and provides methods to study the intermolecular interactions at a deeper level. Structural studies of several thiophene based compounds have been carried out and the phenomenon of disorder has been discussed. Experimental and theoretical charge density analysis of two important molecules was performed using a multipolar atom model. A new virtual atom model is also tested which allows for a rapid calculation of the electrostatic properties. The hydrogen bonding with oxygen atom acceptor is studied through an extensive survey of more than 500,000 crystal structures. The stereo chemical results are compared with the electron density of the oxygen atoms in different chemical environments which give conclusive evidences for the dependence of directionality of hydrogen bonds on the shape and orientation of the electrons lone pairs. Finally, it has been shown that how in the absence of high resolution X-rays data, principle of transferability of electron density parameters between molecules can be used to study the electrostatic properties and the intermolecular interactions. This principle has been successfully applied to a small thiophene based molecule and the large FAD binding protein Cholesterol oxidase
Hanine, Mounir. "Contribution à l'étude par spectroscopie capacitive DLTS des niveaux profonds en vue de la réalisation de jonctions p+n ultra-minces". Rouen, 2003. http://www.theses.fr/2003ROUES037.
This work is divided into three parts. The first part will be devoted to the introduction of the generation-recombination concept, to the summary of the fundamental equations of Shockley and Read's model, and to the analysis of the emission and capture mechanisms of charge carriers. In a second part, all the characterization benches are presented, particularly C(V,T), I(V,T) and DLTS characterization techniques. Then we will discuss DLTS principles, possibilities and limits. Indeed, five techniques of DLTS analysis have been developed and tested. The comparison between these methods focuses on their main criteria of performance, i. E. The level of complexity of their implementation as well as the spectral resolution (that is to say the capacity to distinguish between very close energy levels as far as multiexponential transients are concerned). Finally, we studied a few smoothing techniques in order to suppress the noise influencing experimental signals, and that led us to choose the Discret Wavelet Transform, which seemed the most efficient. The last part of this thesis deals with the development of a new technique of high resolution analysis of capacitance transients. This technique, named LM-DLTS, can serve to maximize the extraction of the physical parameters typical of deep defects, even when the signal-to-noise ratio is very low. As a conclusion, the possibilities of implementing this method are illustrated by the use of DLTS for analysing the concentration profiles of the defects according to their depth, specifically for studying the characteristics of boron diffusion in silicon
Chanteau, Bruno. "Transfert à très haute résolution d'une référence de réquence ultra-stable par lien optique et application à la stabilisation d'un laser moyen-infrarouge". Phd thesis, Université Paris-Nord - Paris XIII, 2013. http://tel.archives-ouvertes.fr/tel-00947696.
Gobron, Olivier. "Lasers ultra-stables asservis sur trous-brûlés spectraux : développement en vue d'une application aux horloges optiques". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066034/document.
Optical lattice clocks show impressive performances and are begining to raise the question of the redefinition of the SI second. In these systems, an ultra-stable laser is used as local oscillator to probe very narrow optical transitions of neutral atoms trapped in an optical lattice. The ultime stability of these systems, determined by the number of atoms interrogated at each clock cycle, evaluated at a few 10−17/sqrt(tau) (where tau is the integration time), is currently not reached and is limited to a few 10−16/sqrt(tau) by the phase fluctuations of the probe laser. If the enhancement of the ultra-stable cavities, on which are currently stabilized the probe lasers, is widely studied, LNE-SYRTE has adopted a more recent approach where the frequency reference is a spectral hole burned in rare earth doped crystal cooled down at cryogenic temperature (around 4 K). A short term stability of a few 10−18 could be achieved. This thesis describes the construction of the experiment and present the results of a high resolution spectroscopy of narrow spectral holes (FWHM = 3.3 kHz) burned in the crystal Eu3+ : Y2SiO5. The influence of the closed cycle cryostat on the behaviour of the spectral holes is hightlighted and reduced. Finally, an original locking scheme based on a heterodyne detection of a spectral hole and a numerical lock program using FPGA in order to stabilize the laser frequency on the top of the narrow spectral hole is described and shows a short term stability of a few 10−14, which is a first promising result for the future of the project
Chanteau, Bruno. "Transfert à très haute résolution d'une référence de fréquence ultra-stable par lien optique et application à la stabilisation d'un laser moyen infra-rouge". Thesis, Paris 13, 2013. http://www.theses.fr/2013PA132054.
This manuscript details the transfer of an ultra-stable optical frequency reference by means of an optical link and its application to the phase-lock of a mid-infared laser. An optical fiber link allows the ultra-stable transfer of a frequency by using a scheme wich compensates the propagation noise. We extended this system to longer links, and transferred the optical frequency reference simultaneously witn internet data. A cascaded link of 300 km and a simple link of 540 km had been demonstrated with a stability of 10⁻ ¹⁹ at 10⁴ s. Such a link as been used to lock a CO² laser at LPL, emitting at 10 µm, to a frequency reference developed at LNE-SRTE, Observatoire de Paris. This reference is an ultra-stable laser, emitting at 1.54 µm, the frequency of wich is measured against the primary standards of LNE-SYRTE by using a femtosecond laser. This reference is tranferred by an optical link to LPL, in order to stabilize the repetition rate of a second femtosecondlaser and to measure or control the frenquency of a CO² laser. When the CO² laser is locked to a molecular reference (OsO₄), the stability is 4.10⁻¹⁴ at 1s. The performances are even better when the CO² laser is locked directly to the optical reference. Then the laser coulb be used for the experiment of observation of the parity violation in chiral molecules, in progress at LPL. This shows the feasability of high resolution molecular spectroscopy experiments in laboratoratories in wich there is no primary standards
Daussy, Christophe. "Spectroscopie de très haute sensibilité avec des molécules et métrologie des fréquences". Habilitation à diriger des recherches, Université Paris-Nord - Paris XIII, 2008. http://tel.archives-ouvertes.fr/tel-00764983.
Cotton, Jérôme. "Application de l'analyse métabolomique à la détection ciblée et globale de contaminants organiques dans des matrices agroalimentaires et environnementales par spectrométrie de masse à ultra-haute résolution". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066094/document.
Pollution of agrifood and environmental water by pesticides and drugs is a real public health concern. There are many quantitative methods developed on triple quadrupole mass spectrometer for their detection, but drug residues and abiotic or biological degradation of pollutants are generally not considered and are limited to a predetermined and restricted list of molecules.In this context, we have developed an analytical method based on metabolomic analyses by high performance liquid chromatography coupled with ultra-high resolution mass spectrometry (LC-HRMS). Two matrices (honey and groundwater) were investigated as proof of concept studies. We showed that LC-HRMS associated to data mining tools enables (i) targeted analyses of pollutants, (ii) detection of untargeted and unknown xenobiotics, and (iii) detection of metabolites useful for the characterization of matrices. Then, a large targeted and semi-quantitative approach has been developed and validated for the detection of pesticides, drugs and metabolites in water samples by using on line SPE and UHPLC-ESI-HRMS. This method allowed the detection of 539 organic contaminants at the MLR of 0.1 µg/L in 36 minutes with only 5 milliliter of water. A study of 26 tap water samples from the Paris region showed the presence of 37 pollutants including 6 drugs
Ziskind, Michael. "Spectroscopie infrarouge à ultra haute résolution appliquée à l'étude de symétries fondamentales dans les molécules : recherche d'un effet de violation de parité et test du postulat de symétrisation". Paris 13, 2001. http://www.theses.fr/2001PA132032.
The first part of this thesis is dedicated to a new search of a parity violation effect, due to weak interaction, in the spectrum of enantiomeric molecules. The principle of the experiment is to compare the frequencies of the rovibrational line centers of both enantiomers of the chiral molecule CHFCIBr. Spectra are recorded simultaneously, with the same frequency stabilized CO2 laser. For this purpose, the spectrometer was optimized and ajusted for the experiment. We also performed an extensive analysis of the hyperfine structure and were able to select a very favorable candidate for the test. This set of measurements led to a sensitivity of 2. 10-14 in relative value, which represents an improvement of more than one order of magnitude on the previous experiment. We finally established the ultimate limits of such an experiment. The second part presents the first test of the symmetrization postulate performed in polyatomic molecules. The symmetrization postulate implies that the energy states, for which either the total internal wavefunction is neither totally symmetric with respect to permutations of oxygenes in OsO4 nor totally antisymmetric with respect to permutations of fluors in SF6 are not populated. The principle of our experiment is to compare rovibrational transitions which connect states forbidden by this postulate to transitions between allowed states. Unlike the previous inventoried experiments, the chosen molecules permit to test forbidden symmetries with a dimension greater than 1. For OsO4, the sensitivity of the effect was established to 5. 10-4 in relative value, limited by the coincidental presence of hot bands with the expected transitions. For SF6, the sensitivity of the effect was limited by the sigal-to-noise ratio to 7,8. 10-6
Cotton, Jérôme. "Application de l'analyse métabolomique à la détection ciblée et globale de contaminants organiques dans des matrices agroalimentaires et environnementales par spectrométrie de masse à ultra-haute résolution". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066094.
Pollution of agrifood and environmental water by pesticides and drugs is a real public health concern. There are many quantitative methods developed on triple quadrupole mass spectrometer for their detection, but drug residues and abiotic or biological degradation of pollutants are generally not considered and are limited to a predetermined and restricted list of molecules.In this context, we have developed an analytical method based on metabolomic analyses by high performance liquid chromatography coupled with ultra-high resolution mass spectrometry (LC-HRMS). Two matrices (honey and groundwater) were investigated as proof of concept studies. We showed that LC-HRMS associated to data mining tools enables (i) targeted analyses of pollutants, (ii) detection of untargeted and unknown xenobiotics, and (iii) detection of metabolites useful for the characterization of matrices. Then, a large targeted and semi-quantitative approach has been developed and validated for the detection of pesticides, drugs and metabolites in water samples by using on line SPE and UHPLC-ESI-HRMS. This method allowed the detection of 539 organic contaminants at the MLR of 0.1 µg/L in 36 minutes with only 5 milliliter of water. A study of 26 tap water samples from the Paris region showed the presence of 37 pollutants including 6 drugs
Habchi, Baninia. "Mise en évidence des perturbations métaboliques liées à l’exposition aux toxiques présents dans l’environnement ou l’aliment par spectrométrie de masse à ultra haute résolution FTMS combinée avec des outils chimiométriques". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLA032.
Public health monitoring involves evaluation of population exposure to environmental toxicants which can have an impact on their health. To do this, robust and high-throughput approaches are required to perform large scale analyses. Global approaches such as metabolomics which aim to reveal metabolic changes due to environmental stress or diseases seem to be the most appropriate approach. This multidisciplinary approach requires powerful analytical techniques such as mass spectrometry (MS) associated with statistical and chemometric data processing. It allows to detect general metabolic disruptions induced by a given physiological or pathological conditions. The studied samples can be injected either directly by the DIMS technique (direct introduction mass spectrometry) or following a chromatographic separation using GC/MS or LC/MS (gas or liquid chromatography / mass spectrometry). The DIMS approach leads to a significant reduction in analysis time, down to only a few minutes (usually less than 3 min). Additionally, in combination with Fourier transform mass spectrometers (DIFTMS), it provides very high mass resolving power and accurate mass measurements, as well as a wide dynamic range resulting in improved efficiency. Nevertheless, the DI-FTMS approach generates complex data containing several thousands of peaks. Processing such large data sets requires the development of dedicated chemometric and statistical tools to detect exposure biomarkers. Therefore, the objective of my work was to develop a rapid, highthroughput workflow, including the development of chemometric tools, in order to highlight metabolomic perturbations induced by exposure to toxicants. The first part of this work concerns the study of farmers professionally exposed to two pesticides. The DIMS approach was performed on an Orbitrap instrument and a new chemometric tool called Independent Component - Discriminant Analysis (IC-DA) was developed for supervised analysis of the DIMS data. The developed methodology was then applied to a larger number of samples corresponding to five types of exposure. In this later study, two analytical approaches DIMS and LC/MS were examined in order to validate the DIMS approach as well as the developed chemometric data analysis tool. In a second part of this work, the DIMS approach was applied to an instrument of higher performances, the FT-ICR (Fourier transform-ion cyclotron resonance) equipped with a dynamically harmonized cell in order to improve the quality of the DIMS data. A first study explored the effects of exposure of rats to different concentrations of pesticides. In a second step, the procedure was applied to a large number of samples (of approximately 500 individuals) to test the robustness of the approach. All this work demonstrated the feasibility and effectiveness of our high-throughput metabolomic approach combining the direct introduction (DIMS), the very high resolution detection and the chemometric tools. This approach could be very promising to perform large scale metabolic phenotyping such as in epidemiological studies
Bardin, Noémie. "Composition isotopique des éléments légers dans les micrométéorites ultracarbonées par spectrométrie de masse à émission ionique secondaire à haute résolution en masse, contribution à la connaissance des surfaces cométaires". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS189/document.
This thesis covers the isotopic analysis of carbon-rich interplanetary dust (ultracarbonaceous micrometeorites), in order to better understand the isotopic fractionation process of light elements (hydrogen and nitrogen) observed in the organic phases of primitive extraterrestrial matter. It is possible, within a collection of micrometeorites coming from the central regions of the Antarctic continent, to identify ultra-carbonaceous micrometeorites (UCAMMs – for Ultra-Carbonaceous Antarctic MicroMeteorites) which contain about ten times more carbon than the primitive meteorites. These particles are extremely rare and open the possibility to study in laboratory cometary particles of large sizes (100-200 microns). This thesis focuses on the isotopic analyses of UCAMMs, in order to understand the isotopic fractionation processes of light elements (hydrogen and nitrogen) observed in the organic matter of the primitive solar system. Mineralogical, chemical and structural analyses on two fragments of ultra-carbonaceous micrometeorites were performed in the framework of collaborations using techniques of scanning electron microscopy, electron microprobe, infrared microspectroscopy (SOLEIL synchrotron). The main work of this thesis concerns the isotopic analysis of two UCAMMs by Secondary Ion Mass Spectrometry (SIMS) using the NanoSIMS ion microprobe. The instrumental developments performed in collaboration between the CSNSM and the Curie Institute teams allow to resolve molecular interferences with a mass resolving power higher than 20 000 retaining a sensibility compatible with the measurements considered here. So, it has been possible to measure for the first time the hydrogen isotopic composition with the polyatomic ions 12C2D- and 12C2H- and to compare its spatial distribution with that of the nitrogen (12C15N-/12C14N-) obtained on the same surface with the same magnetic field. A protocol for producing a series of standard samples was developed from polymers isotopically enriched in deuterium in order to determine the instrumental fractionation of the NanoSIMS showing the possibility to perform precise measurements of the hydrogen isotopic composition in the organic matter with polyatomic ions (CD-/CH- and C2D-/C2H- ratios). The isotopic maps at high spatial resolution (200 nm) in C2D/C2H and C15N/C14N show a very heterogeneous distribution in deuterium with extreme values going up to 20 times the terrestrial ocean value, whereas the 15N/14N ratios remain globally close (within 20%) to the terrestrial atmosphere value. Measurements of N/C ratios in ion imaging performed at the NanoSIMS confirm the values measured by electron microprobe and show that the organic matter of UCAMMs is rich in nitrogen. Comparisons between isotopic images with each other and with the images obtained by the other techniques show that the organic matter of ultracarbonaceous micrometeorites is constituted of different components. The main component doesn’t exhibit a correlation between the D and 15N excesses. A minor component of the analyzed surface exhibits correlated excesses in D and in 15N, without neither the elemental or structural composition of this component significantly differs from the rest of the grain. Finally, a minor component showing moderate enrichments in D and 15N/14N ratios lower than the terrestrial atmosphere value could have been identified.All the data can be explained assuming that the ultracarbonaceous micrometeorites come from the surface of transneptunian icy objects. The elemental and isotopic characteristics observed in the organic matter of UCAMMs might result from the mixing of different strata of the parent body having undergone irradiation by the galactic cosmic radiation at large heliocentric distances
Wollesen, Laura. "Nouveaux films minces scintillants ultra-denses et solutions alternatives pixélisées pour l'imagerie synchrotron par rayon X". Electronic Thesis or Diss., Lyon 1, 2023. https://n2t.net/ark:/47881/m60k28pm.
The development of scintillators with high stopping power for high spatial resolution X-ray imaging at synchrotrons has been performed by employing two approaches. The first approach was to grow thin Single Crystalline Films (SCFs) of high density and effective Z number by Liquid Phase Epitaxy (LPE). This is to reach ultimate high spatial resolution while maximizing the absorption efficiency of the films. Before attempting to develop the LPE procedures, the compounds were investigated with a Geant4, Monte Carlo simulation tool combined with subsequent analytical calculations to evaluate their scintillating spatial response. Ultimate high-density compound, Lu2Hf2O7, and other hafnates have in this framework been successfully grown on ZrO2:Y substrates. The atomic structures of the films were confirmed to be iso-structural with the substrate and have a low lattice mismatch. It was experienced that various elements could enter the structure, and a surprising flexibility of the hafnate system for LPE growth is thereby realized. The grown films of Lu2Hf2O7 doped with Europium are discovered to scintillate. However, the substrate itself displays low-intensity emission. The films have a rather low light output but deliver a good spatial response validated by MTFs as well as when performing radiography and tomography. The second approach was to grow state-of-the-art SCF scintillators in a micro-structured manner by LPE. The aim is to increase the stopping power by having tall pillars containing light and maintaining a good spatial response. LSO:Tb and GGG:Eu, were grown micro-structured onto laser-treated LYSO:Ce and GGG substrates, respectively. The morphology of the pillars varies depending on the compound and the substrate orientation. The atomic structures and luminescent properties are comparable to their normal SCF counterparts. Thereby a proof of concept has been demonstrated
Tran, Dang Bao An. "Widely tunable and SI-traceable frequency-comb-stabilised mid-infrared quantum cascade laser : application to high precision spectroscopic measurements of polyatomic molecules". Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCD060.
The thesis consists in developing a high-resolution mid-infrared spectrometer traceable to primary frequency standards and providing a unique combination of resolution, tunability, detection sensitivity and frequency control. A quantum cascade laser (QCL) emitting at 10.3 µm is phase locked to an optical frequency comb stabilized to a remote 1.55 µm ultra-stable reference developed at LNE-SYRTE, monitored against primary frequency standards and transferred to LPL via an active noise compensated fibre link. This results in a 0.1 Hz QCL linewidth, a stability below 10⁻¹⁵ at 1 s and an uncertainty on its absolute frequency below 4 × 10⁻¹⁴. Moreover, the setup allows the QCL to be widely scanned over 1.4 GHz while maintaining the highest stabilities and precision. This QCL was used to carry out saturated absorption spectroscopy of several molecules in a compact multipass cell. We demonstrated statistical uncertaintyon line-center frequencies at the kHz level and sub-10 kHz systematic uncertainty. We have recorded several singular K-doublets and many rovibrational transitions of methanol, in particular weak transitions and weak doublets - unreported so far. Precise parameters modelling trioxaneh ave been determined with only a few tens of rovibrational transitions recorded at unprecedented accuracy. The quadrupole hyperfine structure of an ammonia transition has been resolved for thefirst time. This setup constitutes a key element for the project aiming at the first observation of parity violation in molecules currently held at LPL, and, more generally, for various fields of physics, from atmospheric and interstellar physics to fundamental physics beyond the standard model
Gosset-Erard, Clarisse. "Développement méthodologique en CE-FTICR-MS pour l'étude de biomolécules à visée thérapeutique". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0219.
Mass spectrometry (MS) has emerged in recent years as benchmark method for the characterization of biomolecules. The development of new analyzers with ultra-high resolution and high mass accuracy, such as Fourier Transform Ion Cyclotron Resonance (FTICR), has improved the selectivity of the method. To ease the characterization of complex samples, MS can be coupled with separative methods such as capillary electrophoresis (CE). CE is the most powerful electrophoretic method in terms of resolution, efficiency and peak capacity, and is very fast. The CE-MS coupling has been developed for a large number of analytes and allows to obtain an optimal sensitivity of MS thanks to the use of a sheathless interface allowing the use of nanoflow rates. However, in order to combine the separation performances of CE, the high selectivity and sensitivity of the sheathless interface with the ultra-high resolution and the high mass accuracy of FTICR-MS, it is necessary to address the technical challenges related to the intrinsic properties of CE and FTICR such as the speed of separation, high peak efficiency and MS acquisition time. The work presented in this manuscript presents the implementation of the CE-FTICR-MS hyphenation and its application for the study of biomolecules, and in particular the characterization of post-transcriptional modifications of ribonucleic acids (RNA). A study of the CE-FTICR-MS hyphenation was first performed using standards, then a first method transfer was performed on biological samples already described in the literature. Various method developments are then presented such as the optimization of the sample preparation, and the development of new bioinformatics tools allowing to go further in the characterization of these modifications and in the complexity of the samples. Finally, the CE-FTICR-MS hyphenation as well as the latest method developments were applied on more complex samples, and whose post-transcriptional modifications are not described in the literature. The use of the CE-FTICR-MS hyphenation for the characterization of RNA enabled the identification of an unknown post-transcriptional modification in one of these complex samples that has not been previously studied in the literature
Fayad, Syntia. "Développement d’outils ultra-performants de criblage enzymatique de produits naturels par électrophorèse capillaire". Thesis, Orléans, 2017. http://www.theses.fr/2017ORLE2032.
Skin aging is one of the exterior/external signs of the passage of time. With age, the skin becomes drier and gets wrinkled due to the degradation of macromolecules of the extracellular matrix by skin enzymes such as elastase, hyaluronidase and collagenase. The aim of this thesis is to develop miniaturized enzymatic assays by capillary electrophoresis to screen plant extracts and identify new bioactives for cosmetics and skin wellbeing. These assays were developed either outside the capillary (which serves only as a separation tool) or in the capillary (which then serves as an enzymatic nanoreactor) then optimized to allow the determination of kinetic constants (Km, Vmax and IC₅₀). Tranvserse diffusion of laminar flow profiles (TDLFP) was applied to mix the reactants injected into the capillary. Detectors such as laser-induced fluorescence or high-resolution mass spectrometry have been coupled to capillary electrophoresis to achieve high sensitivities of detection and the possibility of identifying the products of the enzymatic reaction. These miniaturized assays were applied to algae extracted by electroporation or to regional plants extracted by green technologies in order to evaluate their biological activity towards skin enzymes. The assays developed are reliable, robust and economic in reactants consumption. Finally, the use of a new analytical technique, microscale thermophoresis, was shown to be very useful and hopeful for the study of enzyme-effector interactions
Stoeffler, Clara. "Spectroscopie à très haute résolution de molécules sublimées en jet supersonique : vers une observation de la non conservation de la parité dans les molécules chirales par spectroscopie laser". Phd thesis, Université Paris-Nord - Paris XIII, 2011. http://tel.archives-ouvertes.fr/tel-00647517.
Fohet, Loélia. "Dissémination et vieillissement des particules d'usure de pneumatiques : impacts environnementaux". Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2023. http://www.theses.fr/2023UCFA0056.
Tire and Road Wear Particles (TRWPs) are particles resulting from the abrasion of tires on the road while driving. They are being studied more and more because of their still poorly understood impact on the environment, particularly because of the molecules they can release. Indeed, the composition of tire tread is complex and constitutes a cocktail of chemical products. During this work, ageing of these particles was carried out under accelerated (photoaging and thermoaging) and natural conditions. Then, we followed the evolution of the concentration of 3 additives (antioxidants and vulcanization agents) and 20 transformation products within the particles thanks to liquid chromatography coupled to mass spectrometry. The additives can degrade rapidly - with a half-life of a dozen of days - especially when TRWPs are subjected to photochemical aging. On the other hand, in the dark, the molecules seem to degrade more slowly. As a second step, we studied the evolution of the same molecules when TRWPs are in contact with water, in conditions closer to the environment. Most of the studied molecules are leached little into water compared to the total amount present in the particles. Thus, TRWPs could constitute a reservoir of chemicals in the environment. Finally, we looked for an efficient methodology to identify TRWPs in a sample taken in the environment, through microscopy and infrared imaging, by studying their morphology and their chemical composition
Nancel, Mathieu. "Designing and combining mid-air interaction techniques in large display environments". Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00772458.
Guinet, Mickaël. "Première détermination de la constante de Boltzmann par une méthode optique". Phd thesis, Université Paris-Nord - Paris XIII, 2006. http://tel.archives-ouvertes.fr/tel-00121051.
Dans ce mémoire, je décris les solutions apportées pour obtenir un faisceau laser de fréquence parfaitement contrôlée, largement accordable autour de 10 µm et d'intensité constante. Je décris également les options retenues pour le contrôle en température du gaz d'ammoniac.
Les résultats obtenus sont très encourageants, nous avons après seulement 2 ans déjà obtenu une première mesure de la constante de Boltzmann avec une incertitude relative de 1,9X10-4: k=1,38065(26)X10-23 J.K-1.
Dans ce manuscrit, je présente également plusieurs voies d'amélioration à court et moyen termes.
Je présente enfin une expérience de franges de Ramsey-Bordé référencée sur l'étalon primaire de fréquence localisé à Paris (au SYRTE). La chaîne de mesure absolue de fréquence atteint une résolution de 10-14 et l'incertitude pour la mesure de la frange centrale est également de l'ordre de 10-14. A moyen terme, ce système de mesure par rapport à l'étalon primaire pourra être utilisé pour contrôler la fréquence du laser à CO2 dans les futures expériences de mesure de la constante de Boltzmann.
Guinet, Mickaël. "Première détermination de la constante de Boltzmann par une méthode optique". Phd thesis, Paris 13, 2006. http://www.theses.fr/2006PA132029.
Sagnard, Florence. "Etudes de Propagation et de Rayonnement pour le Développement des Futurs Systèmes de Communication". Habilitation à diriger des recherches, Université de Marne la Vallée, 2008. http://tel.archives-ouvertes.fr/tel-00340853.
Dans le cadre de l'élaboration d'outils de prédiction déterministe de la propagation à l'in-
térieur de bâtiments, entrepris à l'ESYCOM (Marne-La-Vallée) en bande étroite et à l'IETR
(Rennes) en ultra-large bande, nous avons cherché à développer une documentation précise
associée aux comportements de deux éléments du canal de propagation, les matériaux et les
antennes ; l'implémentation de cette documentation dans les simulateurs de canal nécessitera
encore un peu de temps. Notre travail a consisté à développer deux modules particulièrement
originaux traitant, dans les domaines fréquentiel et temporel, de modélisations analytique et
numérique, ainsi que de la caractérisation des matériaux et des antennes à l'aide de bancs de
mesure spéciÞquement réalisés. La spéciÞcité des études conduites tient à la modélisation des
réponses de ces éléments dans le domaine temporel; notamment, nous avons montré que l'ex-
citation d'un matériau par une impulsion génère des échos successifs déformés et atténués dont
l'allure dépend de sa structure (porosité, dimension des grains,...) et des conditions initiales
(température, humidité, ...). Aussi, l'excitation d'une antenne de type résonante produit des
signaux, qui au premier ordre, ont l'allure de la dérivée du signal incident mais ayant subi une
distorsion qui dépend de l'angle d'observation. Ainsi, nous avons remarqué que la largeur de
l'impulsion d'excitation influe non seulement sur l'allure des impulsions rayonnées dans l'espace,
mais aussi sur la direction du maximum de rayonnement. Cette propriété remarquable permet
d'envisager la focalisation d'une antenne ULB dans une direction particulière en modifiant la
durée et la forme de l'impulsion d'excitation. En prévision de l'analyse des trajets multiples d'un canal de propagation ultra-large bande, nous avons abordé leur identiÞcation à l'aide d'al-
gorithmes Haute Résolution (HR) en considérant le canal généré par un matériau du bâtiment.
Les algorithmes, MUSIC modiÞé et Faisceau de matrices, sont fondés sur l'analyse spectrale
paramétrique des données et prennent en compte la dispersion fréquentielle. Ils ont permis de
reconstruire la réponse impulsionnelle de matériaux caractérisés en réflexion.
La modélisation d'une chaîne de transmission a été de plus abordée dans le cadre d'études de
faisabilité du projet "internet-pêche" qui vise à doter des ßotilles de pêche de longueur inférieure
à 25 mètres d'une connexion internet par liaison sans Þl aux fréquences MF-HF ([2 ; 30] MHz).
Une modélisation statistique de la surface de la mer, remuée par le vent, pour un profil de relief
sous-marin donné, a été proposée. Puis, nous avons implémenté le modèle de propagation du
terrain irrégulier afin de rendre compte de la présence d'ondes de sol se propageant sur une
surface de mer considérée comme rugueuse.
Wlotzko, Vincent. "Conception et réalisation d'une caméra à balayage de fente à résolution temporelle picoseconde et à haut taux de répétition". Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAD009/document.
Streak cameras are the direct light detection instruments that are the best in terms of temporal resolution. Those instruments can capture picosecond light events at a hundred megahertz repetition rate. However their characteristics are limited by various phenomena specific to the camera and the implementing system. Several effects that affect the temporal resolution are studied. The first examined line deals with the synchronization of the camera with the studied light event. This inquiry led to the design of a constant fraction discriminator allowing a sub 200 fs RMS jitter triggering. Another study shows the impact of the usually used laser amplitude noise and phase noise on the system’s synchronization. Finally, an analysis of the camera’s photocathode intrinsic phenomena allows estimating the transit time variation of the electrons within the vacuum tube
Sengele, Loic. "Etude des modes octupolaires dans le noyau atomique de 156Gd : recherche expérimentale de la symétrie tétraédrique". Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAE038/document.
Geometrical symmetries play an important role in the understanding of all physical systems. In nuclear structure they are linked to the shape of the mean-field used to describe the atomic nuclei properties. In the framework of this thesis, we have used the predictions obtained with the help of the nuclear mean-field Hamiltonian with the Universal Woods-Saxon potential to study the effects of the so-called “High-Rank” symmetries. These point-group symmetries lead to a nuclear state degeneracy of the order of 4. It is predicted that the tetrahedral symmetry affects the stability of nuclei close to the tetrahedral magic numbers [Z,N]=[32,40,56,64,70,90-94,136]. We have selected the Rare-Earth region close to the tetrahedral doubly magic nucleus 154Gd for our study. In this region, there exists negative parity structures poorly understood. Yet the tetrahedral symmetry, as related to a non-axial octupole deformation, breaks the reflection symmetry and leads to the negative parity states. Following a systematics of experimental properties of the nuclei in this region, we have selected 156Gd as the object of our study for the octupole excitation modes. We have used the reduced transitions probabilities to discriminate between these modes. To achieve this goal, we have performed three gamma spectroscopy experiments at the ILL in Grenoble with the EXILL and GAMS detectors to measure the lifetimes and the gamma transition intensities from the candidate states. The analysis of our results shows that including the tetrahedral shape helps to understand the dipole transition probabilities. This result will open new experimental and theoretical perspectives
Le, Maître Johann. "Développement de la spectrométrie de masse à ultra- haute résolution associée à la spectrométrie de mobilité ionique pour la caractérisation de coupes pétrolières lourdes. structural analysis of heavy oil fractions afterr hydrodenitrogenation by high-resolution tandem mass spectrometry and ion mobility spectrometry Structural analysis of neutral nitrogen compounds refractory to the hydrodenitrogenation process of heavy oil fractions by high-resolution tandem mass spectrometry and ion mobility-mass spectrometry Chemical characterization of 15 biocrudes obtained from hydrothermal liquefaction of industrially cultivated wild micro algae Chemical characterization with different analytical techniques, a way to understand the process: Case of the paraffinic base oil production line Exploring complex mixtures by cyclic ion mobility high-resolution mass spectrometry – Application towards Petroleum. Simulation and modeling of Collision Cross Section for structural elucidation of heavy oil fraction by ion mobility-mass spectrometry: Using polyaromatic hydrocarbons compounds mixture as calibration standard Characterization of sulfoxides compounds in dimeric distribution of heavy oil fractions by positive-ion electrospray ionization FTICR mass spectrometry Structural analysis of Petroporphyrins from asphaltene by trapped ion mobility coupled with a Fourier transform ion cyclotron resonance mass spectrometer. Cyclic ion mobility spectrometry coupled to high-resolution time-of-flight mass spectrometry equipped with atmospheric solid analysis probe for the molecular characterization of combustion particulate matter. Structural study of analogues of Titan’s haze by trapped ion mobility coupled with a Fourier transform ion cyclotron mass spectrometer". Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR051.
The evolution of oil reserves requires the use in refineries of unconventional crude oils, which are often heavier and therefore difficult to characterize. Petroleum products are in fact extremely complex chemical mixtures. The light and volatile part can be analysed by gas chromatography coupled with mass spectrometry (GC/MS), allowing the identification of compounds by using precise mass measurements and fragmentation models. However, these techniques are inappropriate for the analysis of heavy fractions. In practice, the characterization of the most complex mixtures involves the use of ultra-high-resolution mass spectrometers generally by direct analysis without chromatographic separation. The reference technique today is Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR). With a resolution of more than 106 and a mass measurement accuracy of less than 0.1 ppm, this instrument can separate all the species present in a petroleum product and assign a unique elemental composition to each m/z value. This makes it very easy to obtain molecular maps that can be presented graphically using the Kendrick diagram, the van Krevelen diagram or the number of unsaturations (DBE) as a function of the number of carbons. This thesis work has allowed thanks to the molecular characterization of petroleum products (Vacuum Gas Oil, Crude Oil, Interfacial Material, Asphaltenes and Bio-Oil...) addressing the complexity of their treatment in the refining tool. Protocols for sample analysis have been developed, using different sources of ionization at atmospheric pressure (ESI, APCI and APPI) as well as laser desorption/ionization (LDI) on the FTICR 12T mass spectrometer. Information on the isomeric content of petroleum products was then determined using ion mobility spectrometry (IMS)