Dissertations / Theses on the topic 'Spectroscopie à détection synchrone'
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Vieillard, Thomas. "Dynamique induite par champ laser femtoseconde intense : alignement moléculaire en milieu gazeux dense et effet Kerr." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00697019.
Full textWang, Gaoxuan. "Development of photonic instruments for measurement of aerosol optical properties." Thesis, Littoral, 2018. http://www.theses.fr/2018DUNK0470.
Full textAtmospheric aerosols are known to play an important role in earth climate by scattering and absorbing solar radiation. However, the aerosol radiative forcing effect is still known with large uncertainties (almost equal to the magnitude of the aerosol radiative forcing). The uncertainties are mainly caused by inaccurate estimates of aerosol optical properties (such as its absorption, scattering and extinction coefficients) using the currently available measurement techniques, with result in filter loading effect in classic filter technique, the uncertainty due to different sampling conditions for separate measurements of aerosol optical properties in combination of different techniques or due to the measurements at limited spectral wavelength ranges. My PhD work was carried out on the developments and applications of optical and electronic instruments for accurate measurements of aerosol extinction and absorption coefficient : (1) Photoacoustic spectrophones were developed for filter-free direct measurements of aerosol absorption with high accuracy. Measurements uncertainties down to about 7.4% and 4.6% (compared to about 20-30% in filter-based measurements) were achieved for the determination of mass absorption coefficients of black carbon and volcanic ash samples, respectively, using a single-wavelength PA spectrophone operating at 444 nm. A 3-wavelength PA spectrophone operating at 444,532 and 660 nm was developed and deployed for characterizing wavelength-dependent optical properties of aerosol absorption Ångström coefficient (AAC). The determined AAC of black carbon was well consistent with the previously reported value. Our AAC values of two volcanic ash samples from 2010 eruptions of Eyjafjallajökull, similar to the AAC of brown carbon, indicated abundant organic compounds in the volcanic ash samples. The developed multi-wavelength PA spectrophone was tested and validated in an intensive field campaign measurements of environmental particles in Grenoble (France). Side-by-side inter-comparison measurements using an aethalometer showed a lineat correlation of the measured aerosol absorption coefficients from both instruments. (2) An extinctiometer based on IBBCEAS was developed for study of optical properties of secondary organic aerosol (SOA) produced from photolysis of 2-nitrophenol in an atmospheric simulation chamber at University College Cork (Ireland). Simultaneous monitoring of the SOA extinction and absorption (in conjuction with a PA spectrophone) coefficients was performed during its whole production process, the measured evolutions of the SOA optical properties highlighted the atmospheric aging effect. (3) In order to render optical sensor lightweight and suitable for field applications, in particular for the newly emerging unmanned aerial vehicle (UAV) applications, a novel architecture of lock-in amplifier (LIA) was proposed and developed in the framework of this Phd Research. The novel LIA, evaluated with an inter-comparison measurement of ambient NO₂ at the ppbv concentration level, shows an identical performance (in terms of measurements accuracy and precision) as the widely used commercial LIA (SR830, Stanford Research Inc.), while using a simplified and lightweight hardware architecture. Evaluation of the aerosol impact on climate requires accurate and unbiased quantification of the its wavelength-dependent optical properties over a wide spectral region of the major solar radiation, which can provide information on particle size (due to the wavelength dependence of scattering by fine particles) as well as insights on aerosol chemical composition (because of its wavelength selective absorption). To date, it is still a key challenge in atmospheric science and climate change research. Development of a broadband aerosol albedometer is ongoing, which is dedicated to simultaneous measurements of aerosol extinction and absorption coefficients with high-accuracy and high-precision
Garcia, Marine. "Développement d’une plateforme d’imagerie pour la caractérisation du transfert de masse dans les microsystèmes : application aux piles à combustible microfluidiques." Electronic Thesis or Diss., Paris, HESAM, 2024. http://www.theses.fr/2024HESAE007.
Full textFuel cells are devices that convert the energy stored in an oxidant and a reductant into electricity through electrochemical reactions. The most mature technology for this conversion is the proton exchange membrane fuel cell (PEMFC), but other alternative systems are emerging. In particular, microfluidic fuel cells (MFCs) have overcome the problems associated with the use of a membrane and gas storage by using liquid reagents at ambient temperature and pressure. The dimensions of the channel (1-5 mm wide and 20-100 µm high) allow co-laminar flow of the two liquid reagents and the electrolyte in a microchannel containing the electrodes. Therefore, PCMs do not need membrane to separate reactants and performances are driven by charge and mass transport.Experimental characterization of all the physical phenomena involved in PCMs is difficult because actuals methods are more based on electrochemical characterisation. These methods provide an overall characterisation of the system but they do not give precise information on the mass transport phenomena occurring in the channel. To investigate concentration field, numerical modelling is generally used. Numerical methods evaluate the impact of the geometry or the operating conditions on MFC performances. However, the use of these models relies on the knowledge of in-situ parameters such as the diffusion coefficient D and the reaction rate k0. In numerical studies, these parameters are generally approximated leading to a qualitative understanding of the transport phenomena. Furthermore, these numerical studies have not yet been verified by experimental studies.Thus, the main scientific challenge of this thesis is to develop quantitative imaging methods for characterising the concentration field in an operating PCM.To meet this need, an imaging platform based on spectroscopy and three characterisation methods were developed in this thesis. First of all, the work focused on developing an experimental setup based on spectroscopy to study the interdiffusion phenomenon. This study reports the estimation of the diffusion coefficient of potassium permanganate in formic acid. These solutions were specifically chosen because they are used in the PCM developed for the rest of the study.The imaging plateform was then adapted to study the in operando MFC 2D concentration field in steady-state. An analytical mass transfer model (advection/reaction/diffusion) coupled to the 2D concentration field was used to determine the reaction rate. As the concentration variations involved can be very small (few micro-moles), another characterisation technique was implemented to reduce the measurement noise.To improve the signal-to-noise ratio, a method based on modulation of the concentration field was developed. Demodulation of the signal significantly reduced the noise and concentrations of 20 µM were estimated. An analytical model describing the modulated field was established in order to implement an inverse method. The proposed method made it possible to recover the reaction rate associated with the concentration variation.To conclude, the proposed characterisation methods enable the estimation of the mass transfer and the reaction kinetics using the 2D concentration field from an in operando MFC. This technique has been applied to the MFC, but it can be transferred to a micrometric system in which diffusion-advection-reaction phenomena take place
Guibert, Stéphane. "La thermographie infrarouge à détection synchrone appliquée aux matériaux composites." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24372/24372.pdf.
Full textLenain, Bruno. "Microspectrofluorimétrie à excitation laser et détection multicanale : instrumentation - possibilités - applications." Lille 1, 1989. http://www.theses.fr/1989LIL10047.
Full textCaroulle, Marie-Christine. "La fluorescence synchrone et ses applications à l'étude des médicaments." Paris 5, 1994. http://www.theses.fr/1994PA05P254.
Full textAssaf, Ali. "Détection des microorganismes pathogènes par spectroscopie Raman appliquée en agroalimentaire." Nantes, 2012. http://www.theses.fr/2012NANT2113.
Full textThe microbiological safety is a major concern for all actors in the food chain who require reliable and rapid methods to ensure the innocuousness of their manufactured products. Our project aim to develop a procedure based on Raman spectroscopy for the identification of pathogens in the food industry. The bibliographic research present the advantages of this technique, nevertheless, all presented studies prove its low application in the food processing compared to the other industrial areas. Many factors are also not yet studied to confirm its direct application in the regulations. Firstly, we studied the factors influencing the spectral fingerprint of microorganisms. These studies show that discrimination between bacteria depends on their physiological states. A quality criterion has been established to increase the distinction between analyzed species. In a second step, our works is focused to simplify the steps of regulation by proposing several ways of identification. The first way shows the direct analysis of bacterial colonies after the different stages of enrichment and isolation of bacteria. In the other hand, we propose the direct capture of bacteria by antibody-coated surfaces. These different tracks were then validated by analysis of many industrial samples. The obtained results show that Raman spectroscopy meets the requirements recommended by the food manufacturers but the analysis should follow a standardized procedure
Beaumont, Edward. "Contrôle synchrone de la catalyse de NO-synthases par un nano-déclencheur photoactivable dérivé de NADPH." Palaiseau, Ecole polytechnique, 2008. http://www.theses.fr/2008EPXX0030.
Full textArmand, Damien. "Application de la spectroscopie térahertz à la détection de substances sensibles." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00721831.
Full textGuernet, 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.
Full textGrossel, Agnès. "Spectrométrie infrarouge et détection de gaz à l'aide de lasers à cascade quantique." Reims, 2007. http://theses.univ-reims.fr/exl-doc/GED00000774.pdf.
Full textThis Ph. D thesis was realised in the Infrared Laser Spectroscopy team at the Groupe de Spectrométrie Moléculaire et Atmosphérique (GSMA) in REIMS. The purpose was to study some possible applications of quantum cascade lasers for the detection of very weak concentrations of gases and for the measurements of molecular parameters. It consists of three parts. First a rapid overview of nowadays infrared sources and gas detection methods is presented. This overview outlines the great interest of quantum cascade lasers that were chosen for this work. The second part deals with measurements methods of molecules spectroscopic parameters with diode laser and quantum cascade laser. Such methods were applied for the measurements of atmospheric molecules spectroscopic parameters : carbon dioxide and nitrous oxide. Such measurements were linked to a real need for analysis of atmospheric measurements. The N2O measurements were done for the inversion of atmospheric pro_les recorded by the SPIRALE instrument of the Laboratoire de Physique et Chimie de l'Environnement (LPCE) and the CO2 parameters were used to verify LIDAR measurements recorded by the Laboratoire de Meteorologie Dynamique (LMD) of Palaiseau. The QCL were also used for high sensitivity measurements of gas concentration. They were coupled with a photoacoustic sensor developed by the GSMA and this system was optimized to obtain detection limits in the ppb or tens of ppb range for several atmospheric molecules : methane, nitrous oxide, nitric oxide
Bélanger, Marie-Christine. "Détection de carences nutritives par fluorescence active et spectrométrie." Thesis, Université Laval, 2005. http://www.theses.ulaval.ca/2005/22913/22913.pdf.
Full textNutrient deficiencies are responsible for significant reductions of crop growth and yields. In order to reduce their negative impacts, it is important to detect those deficiencies as early as possible. Current methods include plant material collection and chemical analyses that may not provide deficiency detection within the time-window necessary for plant response to recovery fertilization. Reflectance and fluorescence are two methods associated with remote sensing. In this research project we evaluated the potential of reflectance and fluorescence to detect nutrient deficiencies in crops. To do so, we induced three nutrient deficiencies (N, K, Mg) on potato plants. The nitrogen deficiency significantly reduced crop growth contrary to K or Mg deficiencies. The potential of reflectance and fluorescence to detect nutrient deficiencies was related to growth reduction and it was easier to detect nitrogen deficiency than magnesium or potassium deficiencies. We also developed a nitrogen imbalance indicator based on the computation of the compositional nutrient diagnosis (CND). This indicator corresponds to a canonical variable including information coming from 24 reflectance and fluorescence indices. It allowed the detection of nearly 70% of nitrogen-imbalanced plants. Moreover, we also evaluated the impact of the angle of view and of veins density on the detection of nutrient deficiencies using fluorescence. The detection of nitrogen deficiencies was improved when the fluorometer was inclined and faced older leaves or leaves having a lower density of veins. The research project confirmed the potential of reflectance and fluorescence for the detection of nutrient deficiencies; it introduced a new nitrogen imbalance index integrating CND and remote sensing data; and it determined that a near-nadir angle of view was not well-suited for the detection of some specific nutrient deficiencies. This research project will help to improve crop yield in a sustainable management context.
Ettori, Dominique. "Spectroscopie d'autofluorescence induite par laser appliquée à la détection précoce des tumeurs." Paris 13, 1996. http://www.theses.fr/1996PA132005.
Full textGervais, Antoine. "Guides d'onde sur silicium pour la détection du méthane par spectroscopie d'absorption." Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66313.
Full textIn the context of climate change, affordable, but effective and autonomous methane sensors are required to monitor the emissions and the concentration of this potent greenhouse gas in the atmosphere of remote areas, like in northern environments. A promising solution to this need comes from silicon photonics, an integrated optics platform. Integrated waveguides are an essential component for on-chip detection by absorption spectroscopy, where they play the dual role of routing and transducer. Thus, this project aims at improving the performance of the waveguide for this application. The use of slow-light subwavelength grating waveguides (SWG) is proposed to enhance the light-matter interaction. Their periodic segmentation has the effect that a large fraction of the light is propagating through the air, the medium of interest to probe. In addition, we show that the periodicity of the structure, when close but less than half the wavelength, produces the slow-light effect; i.e. the speed of guided light drops sharply. Their propagation losses and their group index are then characterized and compared to conventional strip waveguides for reference. Although the SWG waveguides have an interaction factor greater than strip waveguides, their higher propagation loss limit their performances. Strip waveguides are therefore chosen for further investigation for the sensor application., in addition to being mechanically robust, and easier to design and fabricate. Efforts for on-chip detection of methane have been made with strip waveguides, but the presence of interference fringes is the limiting factor despite the application of a signal processing technique to mitigate them. Other methods are proposed to improve the signal to noise ratio. Finally, we experimentally show that SWG waveguides can support a slow-light regime. A maximum group index of 30 is obtained and it is easily tunable, in both amplitude or wavelength, paving the way for various other applications for this type of waveguide.
Lecellier, Aurélie. "Détection, caractérisation et identification des moisissures par spectroscopie vibrationnelle infrarouge et Raman." Thesis, Reims, 2013. http://www.theses.fr/2013REIMS023/document.
Full textMold contaminants represent a major problem in various areas such as food and agriculture, pharmaceutics, cosmetics and health. Currently, molds identification is based either on phenotypic characteristics, requiring an expertise and can lack accuracy, or on molecular methods, which are quite expensive and fastidious. In this context, the objective was to develop a simple and standardized protocol using Fourier transform infrared (FTIR) spectroscopy combined with a chemometric analysis, allowing to implement an alternative method for rapid identification of molds. In total, 498 fungal strains (45 genera and 140 species) were analyzed using a high-throughput FTIR spectrometer. Partial Least Squares Discriminant Analysis (PLS-DA), a supervised chemometrics method, was applied to each spectrum in the spectral ranges 3200-2800 and 1800-800 cm-1 for the identification process. Using 288 strains, different calibration models were constructed in cascade and following the current taxonomy, from the subphylum to the species level. Blind prediction of spectra from 105 strains at the genus and species levels was achieved at 99.17 % and 92.3% respectively. The establishment of a prediction score and a threshold permitted to validate 80.22% of the obtained results. The implementation of a standardization function (SF) permitted to increase the percentage of well predicted spectra from strains analyzed using another instrument from 72.15% (without SF) to 89.13% and permitted to verify the transferability of the method. Since sufficient mycelial biomass can be obtained at 48h culture and sample preparation involved a simple protocol, FTIR spectroscopy combined with PLS-DA is a very rapid and cost effective method, which could be particularly attractive for the identification of moulds at the industrial level. The results obtained places FTIR spectroscopy among the avant-garde promising analytical approaches, with high discriminant power and identification capacity, compared to conventional techniques
Bittel, Marine. "Détection de polluants chimiques par biocapteurs bactériens couplés à la spectroscopie Raman." Thesis, Nantes, 2017. http://www.theses.fr/2017NANT4113/document.
Full textIn the field of toxicological bioassays, the current biosensors are mostly monoparametric and limited in terms of sensitivity and specificity. A more complete toxicity analysis thus calls for combinations to cross-check the results. In this context, the latest progress in Raman spectroscopy opens new research perspectives on a fast method of observing metabolic responses against toxic agents. Indeed, Raman spectra constitute molecular fingerprints of the observed biological samples, offering a global multiparametric view of their physiology. Based on the premise that the molecular variations triggered by a substance on a microorganism affect its spectral fingerprint, this thesis explores the Raman spectroscopy potential of identifying spectral signatures of targeted toxic effects. That said, proper physiological spectral fingerprints analysis requires complex chemometric methods. In the first part of this work, a particular attention has been given to the elaboration of a statistical strategy to highlight the effects of arsenic on the E. coli bacteria. To confirm the specific aspects of the generated spectral signatures, the study has then been extended to the observation of four microorganisms exposed to different kinds of toxic substances (antibiotic, metal, pesticides, phenol compounds). Spectral analyses lead to the identification of the most impacted macromolecules, allowing evidencing of specific toxic effects. Finally, in partnership with the company Tronico Vigicell (CIFRE partner of the thesis) this approach has also been tested on environmental water samples, making this work an integral part of the search for better environmental pollution monitoring solutions
Guo, Ziang. "Applications de l’optique non-linéaire à la détection d’interactions moléculaires." Paris 11, 2010. http://www.theses.fr/2010PA110241.
Full textThe interaction in the liquid phase between surface and soft molecules of a size around ten to hundreds of atoms allows to build complex functionalized surfaces. Their physical, chemical, optical, biological…properties can be easily tailored. But their characterization is difficult and requires a combination experimental technique. In this work, we have pushed the quantitative analysis of sum frequency generation vibrationnal spectroscopic in the following aspects: modelling of the whole molecule; ab initio calculation of the molecular hyperpolarizability; consideration of the Fermi resonance; surface structure. These allowed us to clarify the complete conformation of the self assembled monolayer of alkanethiols, which is a model system. We then use this reproducible surface to observe the effect of the bacteral adhesion by SFG
Le, Fur Elisabeth, and Patrick Étiévant. "Détection et quantification de molécules d'arôme en sortie de CLHP par ampérométrie pulsée." Dijon, 1994. http://www.theses.fr/1994DIJOS056.
Full textBigourd, Damien. "Etude et détection de polluants atmosphérique dans le domaine THz." Littoral, 2006. http://www.theses.fr/2006DUNK0152.
Full textTerahertz or Far Infrared radiation extends from 100 GHz to 10 THz. This frequency range was considered to be a “spectral gap” due to the considerable technological difficulties in producing a tunable source with reasonable emission powers. Two THz spectrometers have been developed and exploited. The first uses THz pulses and is based on Time Domain Spectroscopy. It is capable of providing a spectrum which extends from few GHz to 1,2 THz within few minutes and has a spectral resolution in the order of few GHz. The second instrument generates continous wave THz photomixing and can reach up to 3 THz with a spectral purity of 5 MHz. After presenting the analytical descriptions and experimentally characterizations of the instruments, we focus on the monitoring and detection of atmospheric pollutants, illustrated by the analysis of cigarette smoke which represents an example of hostile medium. This study reveals the presences of the hydrogen cyanide (HCN), carbon monoxideee (CO) and formaldehyde (H2CO) and allows their concentrations to be measured. This analysis is verified by comparison with standard chemichal methods. The fundamental part of this work is the study of the gas response after a subpicosecond excitation : the free induction decay of carbonyl sulphide that consists of a series of uniformly spaced subpicosecond commensurate transients. A theoretical model is used to understand the classical phenomena. The quasi exponential decrease of the reemitted pulses is linked to the spectral with of the rotational transition while the anharmonicity influences the pulse shape due to the propagation, dispersion and centrifugal distorsion
Omar, Abdelaziz. "Détection ultrasensible de molécules d'intérêts atmosphériques dans l'infrarouge lointain." Thesis, Littoral, 2016. http://www.theses.fr/2016DUNK0430/document.
Full textQThe detection of trace pollutants is an important issue for monitoring air quality. Terahertz spectroscopy, used to probe spectral regions rich in molecular absorption, is an appropriate technique for measuring atmospheric pollution. This work of thesis consisted in developing and characterizing an ultrasensitive spectrometer to measure molecules of atmospheric interest. A terahertz spectrometer was mounted using a frequency multiplication chain emitting up to 900 GHz. The detection sensitivity has been optimized and characterized. In collaboration with the IEMN, a terahertz spectrometer using a vector network analyzer transmitting up to 500 GHz as a source, has been set up and characterized. The potential of terahertz spectroscopy has been demonstrated to monitor in real time the evolution of concentrations of gaseous pollutants during a chemical reaction and to deduce the kinetic rates. Following the rotational transitions of H2CO and CO of a photolysis reaction of formaldehyde, kinetic reaction rates were determined. Detection of radicals is a challenge because of their high reactivity. The configuration of our spectrometer was adapted to optimize sensitivity and to study the photolysis reaction of acetaldehyde using "Photosensitization" by mercury. Frequency modulation and Zeeman effect modulation were used to study HCO. The sensitivity was optimized, quantified HCO and measured over 200 absorption lines. A spectroscopy study of HCO is initiated in order to optimize the parameters of the international data bases
Allouche, Fatmé. "Étude de concepts coronographiques pour la détection directe d'exoplanètes." Nice, 2011. http://www.theses.fr/2011NICE4029.
Full textWith the advent of imaging aperture-synthesis spectro-interferometers the search of exoplanetary systems appears within reach of direct detection both from ground and space as soon as the array are co-phased. The IRAN recombination falls within the principle of Densification. It provides a PSF with a sharp central peak, surrounded by a clean field where direct imaging is possible. I set a laboratory test bench aiming at validating its concept. The basics of IRAN are recalled in this manuscript followed by the SPIE paper highlighting the experimental results. In order to improve further the dynamic range of the PSFs,e two conceptual coronagraphic studies, both based on the AIC, Achromatic Interferential Coronagraph of J. Gay. The first concept, also proposed by J. Gay is called CIAXE. It is a reconfiguration of the AIC into a compact and fully axial coronagraph. The motivation behind this reconfiguration is to facilitate the insertion of the coronagraph at the focus of telescopes. In this manuscript I Recall the basics of the CIAXE and present the experimental results. J describe, in the context of matrix optics, the derivation of the different surface radii, as well as the method conceived and used to determine the thickness difference between the lenses. The second concept, APIC, Absolute Position Interfero-Coronagraph, was conceived for the remocal of the AIC ambiguity. APIC is also a versatile coronagraph in terms of IWA and stellar leakage. The optic behind these characteristics are cylindrical lens doublets. A detailed study of the concept is presented here in the formalism of Fourier optics along with the experimental results of the test bench
Mothe, Emilien. "Spectroscopie de plasma induit par laser appliquée à la détection de résidus d'explosifs." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22134.
Full textThe threat of terrorist attacks remains omnipresent in many high traffic sites. A technique capable of detecting explosives is needed to best address this threat. Initiated by the Ministère de la Défense and the Direction Générale de l’Armement, the project REI ExploLIBS aims to explore the potential of laser-induced breakdown spectroscopy to detect explosive residue. Experimental and theoretical studies are carried out by Bertin Technologies in collaboration with the LP3 laboratory – UMR 6182. The ablation of polymers under different atmospheres permits to characterize the spatial and temporal evolution of the emission of the CN and the C2 molecules. The radius of emission, the temperature and the decrease of the intensity are related to the formation process of the molecules. The additional analysis by the calculation of the composition of the plasma in local thermodynamic equilibrium reveals the presence of molecules in high concentrations in the plasma that are difficult to visualise in optical spectroscopy. These studies led to the development of a portable sensor dedicated to the detection of explosives. The detection rate is estimated at over 90% and the false positive rate below 5%. The current sensitivity limit is estimated at 55 µg.cm-2
Maurin, Eric. "Application de la spectroscopie photothermique à détection mirage à l'étude de l'interface électrolyte." Bordeaux 1, 1987. http://www.theses.fr/1987BOR10630.
Full textHerbin, Hervé. "Spectroscopie sélective de TiCl et NO : détection infrarouge ultrasensible de N2O et N2." Paris 11, 2005. http://www.theses.fr/2005PA112279.
Full textThis PhD thesis deals with the application of recent high resolution spectroscopic methods that are either selective or ultrasensitive. Spectroscopic parameters of stable and transient molecular species, difficult to reach otherwise, are determined. First, selective Fourier transform spectroscopy is used to characterize TiCl4/He and N2O/He plasmas. The spectrum of the whole emission of a plasma and spectra, which select a given class of molecules (for instance short-lived or ions) are simultaneously recorded. In particular, the rovibronic transition X - C of the 48Ti35Cl radical is observed around 3 µm. Its analysis has shown a very weak perturbation, which affects the C 4D1/2 state. Moreover, selective spectra of a N2O/He plasma, expected to only retain the ion lines, have revealed NO rovibronic transitions between the A, C, D and E Rydberg states. Under specific experimental conditions, a Doppler shift of the NO transitions, similar to the one of a positive ion, is observed. An interpretation of this unexpected phenomenon, highlighted for the first time for a neutral molecule, is proposed. Second, spectra with absorption lengths of several tens kilometers are recorded by coupling intracavity laser absorption spectroscopy (ICLAS) and time-resolved Fourier transform spectroscopy (TRFTS). Two different experiments have make it possible to probe, with high sensitivity, relatively wide infrared spectral ranges. Around 2. 5 µm, lots of weak intensity rovibrational transitions of the atmospherically relevant molecule N2O are identified and analysed. Unstable species created in a N2/He plasma are also detected for the first time around 1. 05 µm
Berciaud, Stéphane. "Détection photothermique et spectroscopie d'absorption de nano-objets individuels : nanoparticules métalliques, nanocristaux semiconducteurs, et nanotubes de carbone." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13278.
Full textLoeillet, Benoît. "Planètes extrasolaires à courte période orbitale : de la détection à la caractérisation des Jupiter-chauds." Aix-Marseille 1, 2008. http://theses.univ-amu.fr.lama.univ-amu.fr/2008AIX11054.pdf.
Full textMore than 300 extrasolar planets have been discovered. The variety and diversity of their characteristics are extremely wide. A significant part of them constitute the Hot-Jupiter population, which is strongly different from the planets we found in our Solar System. These planets have a mass from one to few Jupiter masses, and are at very short distance from their parent star (less than 0. 1 AU). The study of this population bring us robust constrains on the formation and evolution models, especially if these planets transit in front of their star. The works I’ve done during my PhD yield to detect and characterise 14 transiting extrasolar planets, thanks to the SuperWASP program and the CoRoT mission combined to the recent SOPHIE spectrograph (OHP). One of them has the shortest orbital period ever detected and another one is the largest massive object ever detected by transit. I’ve also run a new approach in order to detect Hot-Jupiter with a multi-fiber instrument, strongly decreasing the on-telescope time. We show that the FLAMES/GIRAFFE instrument (ESO) could reach a RV precision of 30 ms1. We also demonstrate that a such program is very efficient in order to select the most promising candidates. We then used this approach to do the follow-up of the transiting candidates of the LRc01 and Src01 CoRoT fields. We concluded that an instrument with a large field of view is necessary to be surely efficient. Additionally, I’ve detected and studied the spectroscopic transit of three different planets. This brought to the scientific community strong constrains on those planetary systems, and unveil the presence of a uncommon system : X0-3
Bégon, Cédric. "Intérêt du contrôle de l'émission spontanée pour la détection ultrasensible de molécules fluorescentes." Aix-Marseille 3, 2002. http://www.theses.fr/2002AIX30014.
Full textWe have implemented a fluorescence con-elation spectroscopy (FCS) set up to coefficients for fluorescent organic molecules freely diffusing into a confocal volume of 10 femtolitres (10-15 litres). The technique, which uses Cyanine 5 reporters gives, for a wide range of concentrations (1011 M-10'8 M), the mean number of fluorescent molecules present into the confocal volume and their mean residence time. The detected signal per molecule per unit time is a key parameter which defines the accuracy of the measurements. To improve the FCS technique, we show that a dielectric multilayer mirror located into the confocal volume alters the radiation pattern for the fluorescent molecules and enhances the signal to noise ratio per molecule per unit time
Rossé, Bertrand. "Détection γ [gamma] et faisceaux radioactifs : recherche de noyaux exotiques très déformés." Lyon 1, 2006. http://tel.archives-ouvertes.fr/docs/00/12/04/76/PDF/These.pdf.
Full textThis work is devoted to the search for highly deformed nuclei under extreme conditions of isospin, located near the proton drip-line, around A~130. The experiment was performed at GANIL (Caen) with the SPIRAL radioactive beam facility. The nuclei of interest were produced by fusion-evaporation reactions induced by the neutron deficient 76Kr radioactive beam (T½ = 14. 8 h). γ-rays were detected by the EXOGAM array, composed of 11 segmented germanium clover detectors, for which a new segment calibration method has been developed. To extract fusion-evaporation events of a overwhelming background due to the radioactivity of the beam, the EXOGAM array was coupled with the light charged particle detector DIAMANT and the high acceptance VAMOS spectrometer. The latter was used for the first time to detect fusion-evaporation residues. The detailed data analysis allowed us to demonstrate that the EXOGAM + DIAMANT + VAMOS coupling is operational and essential to investigate the structure of these nuclei. Furthermore, the first γ transition was observed in the very exotic odd-odd 130Pm nucleus. The results have been interpreted with static and dynamic self-consistent microscopic calculations in collaboration with the Theoretical Physicists of the IPN Lyon
Bogaert, Aurore. "Détection et suivi de cellules marquées en micro-imagerie de résonance magnétique." Evry-Val d'Essonne, 2007. http://www.biblio.univ-evry.fr/theses/2007/interne/2007EVRY0005.pdf.
Full textThe work comprised in this thesis involves detection and tracking, using magnetic resonance imaging at 9. 4T, of human bone marrow mesenchymal stem cells (MSC) magnetically labelled with anionic nanoparticles in situ. Firstly we studied the labelled cells in vitro inside an agarose gel preparation in order to determine the experimental conditions required to obtain single cell detection. A protocol based on gradient echo and spin echo experiments was achieved. Subsequently, the MSC were monitored in vivo following implantation with a scaffold during bone reconstruction. The final experiment followed the migration of MSC grafted into the ischemic mouse brain. The lesion was induced by permanent middle cerebral artery occlusion (MCAO). Migration was visualized as a hypointense signal which evolved over time. Another kind of hypointense signal was observed following MCAO, that when characterized, likely corresponding to the biological process of cicatrisation
Almi, Abdenbi. "Etude et optimisation des performances d'un plasma H. F pour la détection en ligne d'aérosols métalliques dans l'air : analyse de l'influence de l'argon sur la détection." Toulouse 3, 1997. http://www.theses.fr/1997TOU30190.
Full textGascon, Hélène. "Détection de traces de gaz par spectroscopie à diode laser : application au sulfure d'hydrogène." Paris 6, 2001. http://www.theses.fr/2001PA066513.
Full textToko, Worou Bio Mikaila. "Outils algorithmiques pour la détection des communautés dans les réseaux." Nice, 2012. http://www.theses.fr/2012NICE4097.
Full textThis thesis concerns the algorithmic aspects of the communities' detection in large graphs. The work can be used by a telecommunications operator whose graphs are associated to telephone calls and SMS or telecommunication networks. In this context, the detection of communities is used for the content recommendation, the analysis of customer data, the classification of Web pages, the detection of Web spamming, marketing activities and others. This thesis is organized around two major parts. In the first part, we introduce the field of detection of communities. Indeed this problem has been studied with different points of view during the last years. The main methods and applications are presented in this descriptive part. In the second part, we present our contribution to the problema. Our contribution consists of two main topics. First, we introduce a new quality function, the fractional arboricity which is more adapted to the problem of detecting communities in social networks. Then, we present a fast and performance guaranteed algorithm to approximate the optimal fractional arboricity and identifies the communities in question. Second, we study the detection of communities by optimizing the modularity, the most used quality function for communities’ detection. We rewrite this function, and then, find new interpretations of the modularity and also links between the modularity and others cut functions. Finally, we propose two heuristics to approximate the optimization of the modularity. The first is an algorithm that approximates the modularity by using the Fiedler vector of the Laplacian matrix of the graph. The second algorithm is a fast heuristic based on the representation of physical interaction of nodes in a metric space. With this representation, we define an attraction/ repulsion mechanism between the vertices and then we obtain clusters in communities. Finally, we combine the optimization of the fractional arboricity and the optimization of the modularity into one communities’ detection tool
Eliet-Barois, Sophie. "Détection, quantification et cinétique TéraHertz de molécules d'intérêt atmosphérique." Phd thesis, Université du Littoral Côte d'Opale, 2013. http://tel.archives-ouvertes.fr/tel-00957068.
Full textTellier, Franklin Gérard Francis. "Détection du ganglion sentinelle par des méthodes optiques : utilisation des photons diffusés et de fluorescence." Strasbourg, 2011. https://publication-theses.unistra.fr/public/theses_doctorat/2011/TELLIER_Franklin_Gerard_Francis_2011.pdf.
Full textThe sentinel lymph node (SLN) method has become the gold standard to detect breast cancer metastasis. Two optical methods of detection and localization of SLN have been implemented. The first is based on the recording of scattered photons in the tissue to detect dye accumulated in the node. The second consists in detecting the emission of fluorescence photons. For both applications the dye selected is the most frequently used in clinical routine: Patent Blue V (PBV). A first optical instrument has been developed, using 4 excitation laser diodes, to discriminate absorption of PBV from that of other tissue chromophores, and one photodiode of detection. Experiments on solutions simulating the optical properties of breast tissue determined that the probe was 30 times more sensitive than the eye. Animal experimentation allowed to verify, in-vivo, the feasibility of the method. Subsequent collaboration with a regional cancer centre has permitted ex-vivo characterization of the prototype using 78 surgical pieces marked with low volumes of PBV and not visually blue. Our parallel studies highlighted an enhancement of the PBV fluorescence quantum yield by a factor of 30 when it was bounded to human serum albumin. Thus, a prototype to detect fluorescence photons has been developed. Its detection threshold is 100 times as low as that of the human eye. Fluorophore-marked nodes were detected in an animal model, with this device and using an appropriate imaging system. This device can localize precisely a marked SLN after percutaneous injection of a fluorescent dye
Dumas, Stéphane. "Détection par spectrométrie en réflectance diffuse de colonies microbiennes endolithiques." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/25988/25988.pdf.
Full textBaranger, Philippe. "Détection du kérozène par imagerie de fluorescence induite par laser, pour application sur foyer aéronautique." Paris 11, 2004. https://tel.archives-ouvertes.fr/tel-00009189.
Full textThe new concepts of aeronautical engines, developed to follow the evolution of the european standards of pollution, are generally based on an improvement of the processes of liquid fuel injection and mixture in the combustion chamber. There is currently no model mature enough to work without experimental validation. The purpose of this thesis is to assess the possibility of measuring the kerosene (jet a1) vapour distribution by plif (planar laser induced fluorescence). That measurement technique must quantitatively image the instantaneous concentrations fields of the vaporized fuel in a spray. The implementation of such a technique needs an experimental spectroscopic study, which was realized on the vapour of fuel. First of all, this study allowed us to determine the properties of the kerosene fluorescence spectrum versus physical parameters such as temperature, pressure or gas mixture composition, especially in presence of oxygen molecules. Then, it was shown that the fluorescence spectrum of the fuel could be reproduce in all physical conditions by a single mixture of four aromatics. Their photophysical properties were also analyzed. Following this spectroscopic study, a phenomenological model for the fluorescence of the gaseous fuel was set up. This model led us to a protocol for an optical diagnostic on this fuel vapour. An experiment was set up to test the implementation and the limits of this technique in simple laboratory conditions. This experiment confirmed that this is indeed a promising technique for the diagnostic of the fuel vapour in aeronautical engine
Ngo, Van Chan. "Vérification Formelle d'un Compilateur Synchrone: de Signal vers C." Phd thesis, Université Rennes 1, 2014. http://tel.archives-ouvertes.fr/tel-01058041.
Full textHafemeister, Collomb Laurence. "Détection, estimation de phénomènes d'onde en analyse d'image : application à l'étude des surfaces marines." Paris 11, 1994. http://www.theses.fr/1994PA112076.
Full textBigourd, Damien. "Etude et détection de polluants atmosphériques dans le domaine THz." Phd thesis, Université du Littoral Côte d'Opale, 2006. http://tel.archives-ouvertes.fr/tel-00120948.
Full textpartie du spectre électromagnétique est encore peu exploitée et a souvent été qualifiée de "gap spectral" en raison des nombreuses difficultés à émettre ce rayonnement à des puissances exploitables. Deux spectromètres dans la gamme THz ont été développés et exploités. Le premier, basé sur la spectroscopie résolue en temps, utilise des impulsions THz et permet d'obtenir un spectre de quelques GHz à 1,2 THz en quelques minutes avec une résolution de l'ordre du GHz. Le second est un spectromètre continu basé sur le photomélange avec
une extension spectrale de 3 THz et une pureté spectrale de 5 MHz. Après des descriptions analytiques et des caractérisations expérimentales des dispositifs, nous nous sommes intéressés à l'étude, à la surveillance et à la détection des polluants atmosphériques dans l'infrarouge lointain en exploitant les deux instruments pour l'analyse de la fumée de cigarette qui représente un excellent exemple de milieu hostile. Cette étude révèle la présence d'acide cyanhydrique (HCN), de monoxyde de carbone (CO), et de formaldéhyde (H2CO). Les concentrations de ces espèces ont été déduites des formes de raies puis confirmées et comparées à des
mesures par méthodes chimiques. La partie fondamentale de ce travail est d'étudier la réponse d'un gaz suite à une excitation subpicoseconde : les signaux de précession libre dans le sulfure de carbonyle (OCS) qui consiste en une série d'impulsions transitoires. Un modèle théorique permet d'interpréter classiquement ces impulsions réémises. La décroissance quasi exponentielle des impulsions transitoires est liée à la largeur de raie des transitions de rotation et les informations d'anharmonicité sont observées sur les formes de ces
impulsions qui sont principalement dues à la propagation, à la dispersion et à la distorsion centrifuge.
Winckler, Pascale. "Spectroscopie de corrélation de fluorescence : fluidité membranaire et détection de molécule unique en solution concentrée." Troyes, 2011. http://www.theses.fr/2011TROY0009.
Full textFluorescence correlation spectroscopy (FCS) is a single molecule technique very well suited for in vivo studies. We have used FCS to explore plasma membrane microfluidity of living cells. Measurements were conducted at the single cell level, which enabled us to get a detailed over-view of the typical plasma membrane microviscosity distribution of each cell line studied (LR73, MCF7, KB3. 1, MESSA and MDCKII). A Monte Carlo simulation based on a 2D diffusion model enables us to link the asymetric fluidity distribution profile with the plasma membrane micro-organization. This result was used to determine the membrane organisation related to the surexpression of the P-glycoprotein (Pgp), a protein implicated in multidrug resistance. We also compare the membrane structuration of various cancer cell lines, each comes in two versions, a sensitive one and a resistant one to a chemotherapeutic drug: the Doxorubicin. Secondly, we propose a new excitation scheme based on a nonradiative energy transfert. This approach allow us to reduce the illumination depth of the microscope at the nanometric scale. We demonstrate its potential through two applications: FCS in micromolar solutions and fluorescence imaging on cells adhesion areas
Bourjilat, Ayoub. "Étude et conception d’une plateforme microfluidique pour la détection de séquence ADN par spectroscopie d’impédance." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0343/document.
Full textThe objective of this thesis is the conception of a biosensor able to detect the presence of DNA sequences without any use of chemical markers or a prior treatment of the samples. The measurements are performed using impedance spectroscopy technique to detect the changes caused by the presence of DNA sequences on the biosensor. Our study is based on analytic and numeric simulations, which allows us to define the dimensions of the sensors adapted to low frequency measurements and to propose an equivalent circuit model taking into account the effects of the electrical double layer. The sensor was manufactured in several steps. Initially, clean room design and manufacturing were optimized for interdigitated structures with different geometries and substrate types (Glass, Si, SiO2). The data analysis of the measurement on standard conductivity and on several DNA concentrations using interdigitated electrode biosensor, allows us to propose a new design with concentric electrodes which is more adapted to low frequency impedance measurement according to a comparative study between interdigitated and concentric electrodes
Léger, Yoan. "Détection de spins individuels dans les boîtes quantiques magnétiques." Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00202472.
Full textLe, Danvic Chrystelle. "Détection de l’oestrus chez les bovins." Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10185/document.
Full textEstrus detection is the critical stage in livestock reproduction. Efficiency of artificial insemination, the major method of reproduction used in cattle, depends on the accurate detection of this short female stage. Currently used detection methods are quite expensive and insecure. This work aims to the elucidation of chemical communication involved in estrus detection by the male. Indeed, male can detect heats by olfactory cues emitted in urine of female. Identification of such chemical cues and their associated binding proteins in estrus behaviour will permit to develop new biotechnological tools as biosensors for estrus detection. To characterize estrus specific molecules, urine from 30 cows was collected at specific stages of the estrus cycle and their chemical composition has been assayed by GC/MS analysis. No systematic estrus specific compounds have been characterized, but we were able to characterize a few compounds as pre-estrus and/or estrus specific in some animals. Identified compounds remain to be tested for their biological activity and ability to elicit sexual behaviour to confirm their implication in estrus detection. No protein binding these molecules could be identified in urine. The urinary serum albumin, described in female elephant urine as a pheromone carrier protein, was characterized. The study of protein in the olfactory area led us to identify several isoforms of bovine Odorant Binding Protein (bOBP), in male and female olfactory tissues. Isoforms can be distinguished by their post-translational modifications. Biochemical experiments showed phosphorylation on one bOBP variant and a N-glycan is present at the N-terminus of the protein. Existence of various bOBP isoforms suggests function specificity, in particular in their binding properties. Spectroscopic fluorescence experiments were performed to analyze the structure-function relationships between the various bOBP isoforms and odorant molecules to ascertain this hypothesis
Le, Minh Hai. "Electrodéposition de film de SnO2 nanostructurés pour la détection électrochimique sans marquage d'ADN." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI091/document.
Full textFor environmental in situ diagnostic, as well as for medical point of care diagnostic, quick andaffordable sensing devices are of importance. Label-free biosensors based on electrical orelectrochemical detection methods can provide such features. In previous studies, we havedemonstrated for the first time the feasibility of using semiconductive SnO2 2D dense films fornon-faradic electrochemical impedance DNA detection. The aim of the present study is (i) toimprove the sensing performances by using SnO2 nanostructures in order to benefit from highspecific surface, and (ii) to study the influence of the morphology and microstructure on theimpedimetric DNA detection signal.We performed the cathodic electrodeposition of SnO2 nanostructures. By changing relevantprocessing parameters, two kinds of nanostructures were deposited: 3D nanoporous films and 1Dnanowires. Both nanostructures have been characterized in terms of morphology, microstructureand electrochemical properties.Our results emphasize the importance of both the microstructural and morphological organizationson the impedimetric signal upon DNA hybridization. Opposite tendencies are found. DNAhybridization induces a decrease of the impedance in the case of 3D-nanoporous films, whereasan increase of impedance is obtained in the case of 1D NWs. Indeed, following the dimensionalityof the nanostructures, either external cause - ion transport - or internal cause - field effectphenomenon - can contribute to the impedance variation.The performances of the sensors have also been analyzed, namely: sensitivity, selectivity andreusability. Compared to the 2D dense and 3D nanoporous films, the 1D SnO2 nanowires are morefavorable in term of sensitivity, showing a detection limit of 2 nM
Martelet, Armelle. "Détection et identification de bactéries dans des matrices complexes par amplification phagique et spectrométrie de masse." Paris 6, 2013. http://www.theses.fr/2013PA066577.
Full textPézeril, Thomas. "Génération et détection d'ondes acoustiques transverses picosecondes : théories et expériences." Le Mans, 2005. http://cyberdoc.univ-lemans.fr/theses/2005/2005LEMA1001.pdf.
Full textPicosecond laser ultrasonics applies opto-acoustic and acousto-optic transformations for the excitation and detection, respectively, of the hypersonic pulses with the duration shorter than hundreds of picoseconds, which are commonly applied for the non-destructive testing of the nanostructures. Starting the pioneering experiments for more than 20 years most of the research has been conducted with longitudinal acoustic mode only. The excitation of quasi-plane acoustic waves is controlled by focusing the femtosecond pump laser pulse on the front surface of the sample to the spot with the diameter significantly exceeding both the depth of the substrate heated region of the material and the distance of sound propagation during the pulsed laser action. Due to this, the diffraction length of the acoustic pulses generated significantly exceeds the characteristic spatial scales involved in echo monitoring of the nanostructures. Unfortunately the layers of the nanostructures are usually elastically isotropic (microcrystalline) or anisotropic (monocrystalline) but with symmetry axis orientation along the normal to the layers. This prevents by symmetry principles excitation of plane shear acoustic waves. The shear mode generation in picosecond ultrasonics is of fundamental issue. One of clear perspectives in the application of coherent shear hypersound is the diagnostics of solid-solid and solid-liquid interfaces and Kapitza resistance by shear phonons. In this thesis, the thermoelastic generation of shear picosecond acoustic waves is analytically treated and experimentally investigated in the case of anisotropic opto-acoustic transducers made of metallic substrate cut off-axis of symmetry. The problematic concerned the thermoelastic generation and the acousto-optic detection of the picosecond shear acoustic waves. First, the thermoelastic generation theory in anisotropic materials is developed to characterize the efficiency of generation and to fully understand the physical processes. That merged on the description of a new volumetric but non-local mechanism of plane shear waves excitation through thermoelasticity which is operative even in crystals with isotropic thermal expansion (in cubic crystals). The theory of the acousto-optic detection in such anisotropic material is also developed. The using of the metallic substrate as a transducer and sensor of picosecond shear acoustic pulses is opportune. Second, the picosecond acoustic experiments are realized with monocristallines substrates of zinc cut off-axis of symmetry. Thanks to the theoretical predictions, the signals can be interpreted and analyzed. Experimentally, the efficiency of the thermoelastic generation is proved. The full numerical computation of the reflectivity signals gave a set of the zinc photoelastic coefficients. Finally, the extension to a zinc polycristalline sample, natively without grain preferenced orientation (001), also proved to be efficient
Bendriaa, Loubna. "Etude et caractérisation de biocapteurs bactériens luminescents pour la détection de molécules et de microorganismes." Le Mans, 2005. http://cyberdoc.univ-lemans.fr/theses/2005/2005LEMA1024.pdf.
Full textMadon, Lydie. "Etude d'un dispositif destiné à la détection en continu d'aérosols métalliques dans l'air." Toulouse 3, 1996. http://www.theses.fr/1996TOU30035.
Full textLe, Garrec Hélène. "Etude et optimisation de la limite de détection en spectrophotométrie d'absorption atomique : contribution à la compréhension des mécanismes en milieu eaux naturelles." Brest, 1997. http://www.theses.fr/1997BRES2006.
Full textGallion, Philippe. "Pureté spectrale d'un laser semiconducteur synchronisé : applications à la détection optique cohérente." Montpellier 2, 1986. http://www.theses.fr/1986MON20090.
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