Tesis sobre el tema "Imagerie IR"
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Ogunleke, Abiodun. "Imagerie chimique 3D de tumeurs du cerveau". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0040/document.
Texto completoThree-dimensional (3D) histology is a new advanced tool for cancerology. The whole chemical profile and physiological characteristics of a tissue is essential to understand the rationale of pathology development. However, there is no analytical technique, in vivo or histological, that is able to discover such abnormal features and provide a 3D distribution at microscopic resolution.Here, we introduce a unique high- throughput infrared (IR) microscopy method that combines automated image correction and subsequent spectral data analysis for 3D-IR image reconstruction. I performed spectral analysis of a complete organ for a small animal model, a mouse brain with animplanted glioma tumor. The 3D-IR image is reconstructed from 370 consecutive tissue sectionsand corrected using the X-ray tomogram of the organ for an accurate quantitative analysis of thechemical content. A 3D matrix of 89 x 106 IR spectra is generated, allowing us to separate the tumor mass from healthy brain tissues based on various anatomical, chemical, and metabolic parameters. I demonstrate for the first time that quantitative metabolic parameters (glucose, glycogen and lactate) can be extracted and reconstructed in 3D from the IR spectra for the characterization of the brain vs. tumor metabolism (assessing the Warburg effect in tumors). Our method can be further exploited by searching for the whole spectral profile, discriminating different anatomical landmarks in the brain. I demonstrate this by the reconstruction of the corpus callosum and basal ganglia region of the brain
N'Doume, Claude Thierry. "Traitement de l'imagerie meteosat IR pour l'observation des aérosols désertiques au-dessus de l'Afrique : optimisation, validation et application à l'établissement des distributions spatio-temporelles". Lille 1, 1993. http://www.theses.fr/1993LIL10146.
Texto completoKrause, Kevin. "Caractérisation infrarouge operando des électrolyseurs à membrane électrolytique polymère pour la séparation de l'eau". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0022.
Texto completoUnderstanding and improving mass and ionic transport mechanisms within the membrane used in polymer electrolyte membrane (PEM) water splitting electrolyzers is vital for achieving improved efficiencies that would enable the use of water electrolysis in sustainable energy infrastructures. A better understanding of mass and ion transport within the PEM are essential to achieving the improved performance and efficiencies necessary for wide-scale commercialization of these devices. The work from this thesis aims to improve characterization methods for measuring PEM hydration using an operating microfluidic PEM electrolysis chip coupled with operando infrared (IR) spectroscopy. This development of this thesis is organized through two parts.In part one and prior to the development of the microfluidic electrolyzer, the experimental setup for IR characterization via Fourier transform infrared spectroscopy (FTIR) and IR thermography was developed. This setup was tested through a microfluidic chip designed for semi-transparency in mid-wave IR light. Two exothermic acid-base reactions were imaged in the chip to simultaneously quantify heat and mass transport in the microfluidic channel. Concentration fields of each chemical species and thermal fields of the chemical reactions were resolved from the acquired IR images. Experimental results were used to validate an advection diffusion simulation of the chemical reaction within a meshed replica of the microfluidic chip, for which there was a strong agreement between the results from each dataset.In part two, the methods from part one were honed for the fabrication of the first microfluidic PEM water electrolyzer for transmission-based IR characterization. The water content within the PEM of the microfluidic water electrolyzer was characterized through two operando IR spectroscopy setups. The first IR experimental setup utilized a synchrotron FTIR spectroscopy setup, where the water content of the PEM was quantified using IR for the first time, albeit only at a single point. The second microfluidic PEM electrolyzer setup used a broadband IR source combined with other techniques to distinguish contributions from ohmic, kinetic, and mass transport losses while acquiring IR images. Images were acquired during potentiostatic operation for a range of anolyte concentrations. Electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) unveiled that higher anolyte concentrations were accompanied by reduced ohmic losses but higher kinetic and mass transport losses. The higher mass transport losses were investigated through images averaged over comparable time scales to EIS and DRT results, and implied that inefficient gas removal occurred at the cathode. These effects were further investigated through the PEM hydration (λ_(H_2 O)) via three characteristic regions where the adjacent channels were either wet, dry, or a mix of both. The local channel wetness was observed to strongly affect the PEM’s hydration through gradients that manifested between cathode and anode channels.Results from this thesis show the potential of transmission-based IR techniques for elucidating transport mechanisms in PEMs of operating microfluidic electrolyzers. Implementing layers that are traditionally implemented in fuel cells and electrolyzers for gas-liquid management into the microfluidic PEM electrolyzer could greatly improve results obtained from the presented methods. Consequently, IR techniques could potentially be used to achieve the contactless quantification of phenomena such as electro- or thermo-osmotic drag. The findings in this thesis provide valuable insights for membrane characterization in electrochemical devices with integrated PEMs, and will inform the next generation of electrolyzer design
Benard, Audrey. "IR imaging in breast cancer: from histopathological recognition to characterization of tumour microenvironment". Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209682.
Texto completoIn a first step, recording and processing methodology had to be defined in order to optimally compare IR spectra. The methodology developed and the analysis tools tested on carcinoma cell lines, demonstrated that spectra could be distinguished based on the cell line phenotypic nature.
The potential of IR imaging for breast tissular structure differentiation was highlighted in this thesis, demonstrating that spectral signature can be correlated with the major histological cell types observed in breast disease tissues. In order to develop a robust algorithm translating spectral data into helpful histopathological information, a spectral database of histologically well-defined breast tissues was built and used for the development of a cell type classifier. This latter one was extensively validated on independent clinical cases. Firstly, the IR-based histopathological classifier correctly assigned spectra acquired on eleven breast disease samples based on their histological nature. Secondly, lymphocyte and Collagen & Fibroblasts spectral signatures were demonstrated to be independent from tissue type and organ since, although trained on reference spectra recorded into breast disease samples, the cell type classifier correctly assigned spectra acquired on lymph nodes/tonsils and scar tissues respectively. Thirdly, we concluded that spectroscopically, breast carcinoma cell lines in culture are well-suited tumour models since spectra acquired on these carcinoma cell lines were correctly recognized as epithelium by the IR-based histological classifier.
By spectral characterizing lymphocytes from lymph nodes and tonsils, we demonstrated that the spectra acquired contained enough information to statistically discriminate them according to their lymphocyte activation states. Although considered as activated, the breast disease lymphoid infiltrates were found to present distinct spectral signature from lymphocytes acquired on activated lymph nodes and tonsils. Furthermore, tumour microenvironment, characterized by IR-imaging was demonstrated to exhibit a distinct spectral signature from wound healing tissues. These studies proved the uniqueness of the signature of both lymphoid infiltrate and tumour microenvironment in breast disease context. Correlating these specific spectral signatures to patient outcome and therapeutics response could help better consider the uniqueness of the patient. In a last step, considering the epithelial signature of carcinomas of both low and high grades, we demonstrated that the biochemical information reflected in the IR micro-spectra was clinically relevant for grading purpose.
Le cancer du sein est le cancer le plus fréquemment diagnostiqué chez les femmes dans les pays occidentaux. Jusqu’à peu, les cellules épithéliales tumorales étaient vues comme les seuls acteurs de la carcinogenèse ;processus se déroulant dans un milieu extracellulaire considéré au pire comme passif ou permissif à l’évolution tumorale des cellules épithéliales adjacentes. Cependant, de nombreuses études ont montré que ce microenvironnement tumoral pouvait soit promouvoir le processus de carcinogenèse soit le combattre empêchant par la même, l’occurrence de la maladie.
Ce projet de thèse s’inscrit dans une problématique actuelle, à savoir une meilleure compréhension de la maladie mais également une prise en charge plus individualisée des patientes. Nous abordons ici une voie de recherche novatrice basée sur la signature globale des molécules cellulaires via leur spectre infrarouge. La technologie utilisée, à savoir la spectroscopie infrarouge, nous fournit une observation quantitative et qualitative de milliers de vibrations moléculaires. L’adaptation de réseaux de plusieurs milliers de détecteurs indépendants aux microscopes infrarouges permet, grâce aux méthodes statistiques multivariées, d’investiguer l’architecture macromoléculaire des cellules au sein d’une coupe tissulaire et de corréler les informations spectrales ainsi obtenues à l’histopathologie des tissus. Par cette technologie, nous visons à mettre au point un outil diagnostique et pronostique pour le cancer du sein basé sur l’imagerie IR.
Durant ce projet, nous avons montré que les différents types cellulaires observés dans les carcinomes mammaires pouvaient être distingués par le biais de leur spectre IR, qu’un modèle de reconnaissance histologique pouvait être construit, validé et surtout automatisé et que ce modèle pouvait être transposé à l’étude d’autres tissus (ganglions, amygdales et cicatrices) et d’autres types d’échantillons (cellules épithéliales en culture). Nous avons également montré que les spectres de cellules épithéliales pouvaient être corrélés au grade histopathologique de la tumeur. Les spectres acquis de ganglions/amygdales ont montré que les profils spectraux pouvaient être corrélés à l’état d’activation lymphocytaire. De plus, l’étude de l’état d’activation lymphocytaire et fibroblastique a permis de mettre en avant un profil spectral propre et bien distinct des infiltrats lymphocytaires d’une part et de la matrice extracellulaire aux abords des tumeurs invasives d’autre part.
Doctorat en Sciences agronomiques et ingénierie biologique
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Bu, Lulu. "Synthesis of NIR Dyes and Nanoparticles for in vivo Bioimaging and Dicyanovinyl Dyes for Primary Amine Detection". Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN086.
Texto completoFluorescence and photoacoustic (PA) imaging are both powerful tools for visualization of biological tissues and organs in non-invasive ways. However, these technologies are limited by the lack of efficient contrast agents. NIR light (650-900 nm) with relatively low absorption and scattering in organisms allows for deeper in vivo imaging, lower auto-fluorescence as well as a good signal to noise ratio. Hence, design and synthesis of efficient NIR organic dyes are of great significance for fluorescence or PA bio-imaging. Meanwhile, encapsulation of organic dyes in nanoparticles dispersible in water present great potential in bio-optical imaging, offering the advantages of high brightness, good photo-stability, excellent biocompatibility and potential targeting ability, etc. Our main goal in this thesis is to synthesize novel organic contrast agents for in vivo fluorescence or PA imaging
Chausse, Eric. "Test et modélisation de détecteurs infrarouges microbolométriques à température ambiante". Grenoble INPG, 2000. http://www.theses.fr/2000INPG0021.
Texto completoHuijts, Julius. "Broadband Coherent X-ray Diffractive Imaging and Developments towards a High Repetition Rate mid-IR Driven keV High Harmonic Source". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS154/document.
Texto completoSoft X-ray sources based on high harmonic generation are up to now unique tools to probe dynamics in matter on femto- to attosecond timescales. High harmonic generation is a process in which an intense femtosecond laser pulse is frequency upconverted to the UV and soft X-ray region through a highly nonlinear interaction in a gas. Thanks to their excellent spatial coherence, they can be used for lensless imaging, which has already led to impressive results. To use these sources to the fullest of their potential, a number of challenges needs to be met: their brightness and maximum photon energy need to be increased and the lensless imaging techniques need to be modified to cope with the large bandwidth of these sources. For the latter, a novel approach is presented, in which broadband diffraction patterns are rendered monochromatic through a numerical treatment based solely on the spectrum and the assumption of a spatially non-dispersive sample. This approach is validated through a broadband lensless imaging experiment on a supercontinuum source in the visible, in which a binary sample was properly reconstructed through phase retrieval for a source bandwidth of 11 %. Through simulations, the numerical monochromatization method is shown to work for hard X-rays as well, with a simplified semiconductor lithography mask as sample. A potential application of lithography mask inspection on an inverse Compton scattering source is proposed, although the conclusion of the analysis is that the current source lacks brightness for the proposal to be realistic. Simulations with sufficient brightness show that the sample is well reconstructed up to 10 % spectral bandwidth at 8 keV. In an extension of these simulations, an extended lithography mask sample is reconstructed through ptychography, showing that the monochromatization method can be applied in combination with different lensless imaging techniques. Through two synchrotron experiments an experimental validation with hard X-rays was attempted, of which the resulting diffraction patterns after numerical monochromatization look promising. The phase retrieval process and data treatment however require additional efforts.An important part of the thesis is dedicated to the extension of high harmonic sources to higher photon energies and increased brightness. This exploratory work is performed towards the realization of a compact high harmonic source on a high repetition rate mid-IR OPCPA laser system, which sustains higher average power and longer wavelengths compared to ubiquitous Ti:Sapphire laser systems. High repetition rates are desirable for numerous applications involving the study of rare events. The use of mid-IR wavelengths (3.1 μm in this work) promises extension of the generated photon energies to the kilo-electronvolt level, allowing shorter pulses, covering more X-ray absorption edges and improving the attainable spatial resolution for imaging. However, high repetition rates come with low pulse energies, which constrains the generation process. The generation with longer wavelengths is challenging due to the significantly lower dipole response of the gas. To cope with these challenges a number of experimental configurations is explored theoretically and experimentally: free-focusing in a gas-jet; free-focusing in a gas cell; soliton compression and high harmonic generation combined in a photonic crystal fiber; separated soliton compression in a photonic crystal fiber and high harmonic generation in a gas cell. First results on soliton compression down to 26 fs and lower harmonics up to the seventh order are presented.Together, these results represent a step towards ultrafast lensless X-ray imaging on table-top sources and towards an extension of the capabilities of these sources
Belmerhnia, Leïla. "Approches parcimonieuses pour la sélection de variables et la classification : application à la spectroscopie IR de déchets de bois". Electronic Thesis or Diss., Université de Lorraine, 2017. http://www.theses.fr/2017LORR0039.
Texto completoIn this thesis, innovative techniques for sorting wood wastes are developed. The idea is to combine infrared spectrometry techniques with robust data processing methods for classification task. After exposing the context of the work in the first chapter, a state of the art on the spectral data classification is presented in the chapter 2. The third chapter deals with variable selection problem using sparse approaches. In particular we propose to extend some greedy methods for the simultaneous sparse approximation. The simulations performed for the approximation of an observation matrix validate the advantages of the proposed approaches. In the fourth chapter, we develop variable selection methods based on simultaneous sparse and regularized representation, to increase the performances of SVM classifier for the classification of NIR spectra and hyperspectral images of wood wastes. In the final chapter, we present the improvements made to the existing sorting systems. The results of the conducted tests using the processing software confirm that significant benefits can be achieved in terms of recycled wood quantities
Belmerhnia, Leïla. "Approches parcimonieuses pour la sélection de variables et la classification : application à la spectroscopie IR de déchets de bois". Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0039/document.
Texto completoIn this thesis, innovative techniques for sorting wood wastes are developed. The idea is to combine infrared spectrometry techniques with robust data processing methods for classification task. After exposing the context of the work in the first chapter, a state of the art on the spectral data classification is presented in the chapter 2. The third chapter deals with variable selection problem using sparse approaches. In particular we propose to extend some greedy methods for the simultaneous sparse approximation. The simulations performed for the approximation of an observation matrix validate the advantages of the proposed approaches. In the fourth chapter, we develop variable selection methods based on simultaneous sparse and regularized representation, to increase the performances of SVM classifier for the classification of NIR spectra and hyperspectral images of wood wastes. In the final chapter, we present the improvements made to the existing sorting systems. The results of the conducted tests using the processing software confirm that significant benefits can be achieved in terms of recycled wood quantities
Petay, Margaux. "Multimodal and multiscale analysis of complex biomaterials : optimization and constraints of infrared nanospectroscopy measurements". Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASF092.
Texto completoIn the biomedical field, understanding the physicochemical changes at the cellular level in tissues can be crucial for unraveling the mechanisms of pathological phenomena. However, the number of techniques providing chemical descriptions at the cellular/molecular level is limited. Infrared (IR) nanospectroscopy techniques, particularly AFM-IR (Atomic Force Microscopy-infrared), are promising as they offer materials' chemical descriptions at the nanometer scale. Up to now, AFM-IR is mainly used in biology for studying individual cells or micro-organisms, but its direct application in biological tissues is relatively scarce due to tissue sections' complex nature. Yet, many applications could benefit from such description, such as mineralization phenomena in breast tissue. Breast microcalcifications (BMCs) are calcium-based deposits (such as calcium oxalate and calcium phosphate) hypothesized to be associated with some breast pathologies, including cancer. Despite increased research over the past decade, BMCs' formation process and connection with breast conditions remain poorly understood. Still, BMCs nanoscale chemical speciation might offer new insights into their chemical architecture. However, breast biopsies typically range from a few millimeters to a few centimeters, containing many BMCs ranging from hundreds of nanometers to a millimeter. Thus, a breast biopsy multiscale characterization strategy is required to provide both a global chemical description of the sample and a fine chemical description of BMCs. We, thus, propose a new multimodal and multiscale approach to investigate BMCs' morphological properties using scanning electron microscopy and their chemical composition at the microscale using IR spectromicroscopy, extending up to the nanometer scale thanks to AFM-IR analysis. Although AFM-IR measurements of inorganic and crystalline objects can be challenging due to their specific optical and mechanical properties, we demonstrate AFM-IR capabilities to characterize pathological deposits directly in biological tissues. Furthermore, implementing a multimodal and multiscale methodology comes with significant challenges in terms of sample preparation, measurements, data processing, and data management, as well as their interpretation: challenges which will be outlined and addressed
Ceamanos, Garcia Xavier. "Evaluation des performances de l'analyse statistique et physique d'images hyperspectrales de Mars. Application au capteur multi-angulaire CRISM". Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENU033/document.
Texto completoNew generation of imaging spectrometers are emerging in the field of space exploration by adding an additional view of measurement, the angular dimension. Multi-angle imaging spectroscopy is conceived to provide a more accurate characterization of planetary materials and a higher success in separating the signals coming from the atmosphere and the surface. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter is a hyperspectral camera that operates systematically in multi-angle mode from space. Nonetheless, multi-angle hyperspectral images are related to problems of manipulation, visualization and analysis because of their size and complexity. In this framework, this PhD thesis proposes robust statistical and physical algorithms to analyze images acquired by the CRISM instrument in an efficient manner. First, I propose a tailor-made data pipeline aimed at improving the radiometric quality of CRISM data and generating advanced products, the latter data being devised to perform fine analysis of the planet Mars. Second, I address the atmospheric correction of CRISM imagery by exploiting the multi-angle capabilities of this instrument. An innovative physically-based algorithm compensating for atmospheric effects is put forward in order to retrieve surface reflectance. This approach is particularly used in this thesis to infer the photometric properties of the materials coexisting in a specific site of Mars, the Gusev crater. Third, I perform an intercomparison of a selection of state-of-the-art techniques aimed at performing spectral unmixing of hyperspectral data acquired by the CRISM instrument. These statistical techniques are proved to be useful when analyzing hyperspectral images in an unsupervised manner, that is, without any a priori on the scene. An original strategy is proposed to discriminate the most suitable techniques for the exploration of Mars based on ground truth data built from independent high resolution imagery
Bayareh, Mancilla Rafael. "Towards a Tool for Diabetic Foot Diagnosis using a 3D Modeling Based on Thermographic and Visible Spectrum Images". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0142.
Texto completoMedical infrared thermography is a quantitative method for identifying irregular temperatures for medical diagnosis. Because abnormal body temperature is a natural sign of illness, this modality's data can be used to detect disease or physiological abnormalities, such as diabetic foot which is the subject of this thesis According to the International Diabetes Federation, nearly half a million people were diagnosed with diabetes mellitus in 2019. Peripheral neuropathy may affect 40 % to 60 % of individuals because of diabetic foot issues. Amputation below the knee joint as a preventive operation is a common risk among these individuals, and it is estimated that one amputation occurs every 30 seconds around the world. Currently, MRI, radiography, and thermography, together with image processing techniques, are among the medical imaging modalities utilized to diagnose the diabetic foot early. Medical infrared thermography, on the other hand, is a non-contact, non-invasive, and non-ionizing passive approach. Infrared imaging of the diabetic foot is still mostly reliant on 2D images that only show a portion of the anatomy. In this scenario, a 3D thermal model would allow for better observation and inspection of the region of interest, which includes the plantar, lateral, and dorsal areas. The use of 3D modeling for the diagnosis of the diabetic foot has been documented in a few articles at the publication of this thesis.The proposed method employs a series of merged infrared and visible spectrum images as data input for the 3D point cloud estimation and surface reconstruction, based on Structure from Motion and Multi-view Stereo methods. However, segmentation in thermal images is a task that remains manually performed since the detection of descriptive features is almost impossible in false-color images. Therefore, this thesis presents an automatic segmentation method based on the processing of radiometric information before generating a false-color image. Radiometric data processing is an alternative to digital image processing due to the feasibility to remove thermal interferences (e.g. lamp, thermal shadows, or even patient body parts) based on temperature threshold criteria, improving color contrast, and segmenting the region of interest, and combine onto visible spectrum images.The fused multimodal images were used as input information for the estimation of the 3D surface of the foot. The obtained model was provided with a temperature scale related to the radiometric data obtained by each volunteer, as well as the possibility to rotate the model to observe each viewpoint. The findings show that the 3D multimodal model is feasible, allowing for better and faster visualization of temperature distribution during diabetic foot diagnosis. The contribution of this thesis concerns the acquisition of a 3D model with thermal information and automatic segmentation in thermal images for multimodal fusion. The perspective is the clinical validation to pilot test the assistance in the diagnosis of diabetic foot. However, from the experimental/theoretical perspective, it is contemplated to study the accuracy of image registration with the proposed method of automatic segmentation, and the thermal and spatial accuracy of the 3D models carried out with phantoms
Bourgeois, Florian. "Développement de matériaux thermistors pour applications bolométriques". Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENI069.
Texto completoMicrobolometers FPAs are nowadays the most advanced technology for uncooled IR imaging. Developments at CEA-LETI are based on the use of amorphous silicon as thermistor material. Introduction of an alternative material is necessary to keep on improving detectors performances. This study considersnanocrystalline oxides thin films as an alternative material. Two deposition techniques have been studied : IBS and MOCVD. Process studies as well as materials characterizations allowed us to control and understand the involved micro-structural evolutions. Electrical characterizations (resistivity, TCR, 1/f noise) on integrated devices were achievedin order to estimate the potential of these new materials. Microstructure-property relationships are also discussed
Le, Pivert-Jolivet Tania. "Composition, origine et évolution de Ryugu à travers les analyses de MicrOmega/Curation". Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASP192.
Texto completoPrimitive asteroids are small bodies that have evolved relatively little since their formation. They contain information about the chemical composition of the early solar system and its evolution up to the present day. Before the 2020s, the only potential analogs of these objects available for laboratory analysis were carbonaceous chondrites (CCs). But the link between CCs and their asteroidal parent bodies is not yet clear, and the primitive composition of CCs is partially altered by interaction with the terrestrial atmosphere. This is why, in the 2010s, two space missions observed and collected samples from the surface of primitive asteroids: they represent the first laboratory study of fragments representing their parent bodies. The C-type near-Earth asteroid (162173) Ryugu, was the target of the Hayabusa2 mission (JAXA). The spacecraft performed two samplings, collecting surface and subsurface samples excavated by an artificial impactor. In December 2020, the sealed capsule containing 5.4g of samples returned to Earth and was opened in the Curation Facility (Sagamihara, Japan), a complex containing a set of clean chambers for carrying out an initial analysis of the grains, preserving their integrity and without exposing them to the terrestrial atmosphere. The aim of my thesis was to characterize the composition of Ryugu samples to retrace the evolution of the primitive matter at different stages in the history of the solar system. Thus, I analysed data acquired by the near-infrared (0.99 – 3.65 μm) hyperspectral microscope MicrOmega, installed in the Curation Facility. MicrOmega enables a non-invasive characterization of the mineral and organic composition of the grains. I studied the 2.7 μm band, characteristic of the vibration of the -OH group in the phyllosilicates of the samples. I carried out a statistical study of the variations in the position and depth of the band between several hundred millimetre-sized grains, which indicate a variation in the composition of the phyllosilicates. This analysis suggests that some of the grains collected at the surface experienced space weathering, a process that affects the composition and microstructure of the surface of airless bodies. Conversely, all the grains from the subsurface have undergone a limited exposure to the space environment. This study also shows that the Ryugu samples are depleted in water (H₂O) compared with CI chondrites, despite their similar mineralogy, and suggests that a significant proportion of the water in the CIs could be of terrestrial origin. I then studied the variations in the shape and position of the 2.7 μm band at the surface of the grains. I showed that the spectral heterogeneity of the surface varies from one grain to another. This variation in heterogeneity could be linked to variations in the degree of aqueous alteration and/or the degree of space weathering on surfaces with different roughnesses. This study shows the potential of infrared hyperspectral imaging to detect variations in the water content between the grains, without any bias by the terrestrial atmosphere. This work provides a better understanding of the physical and chemical evolution of the surface and the near subsurface of primitive asteroids. It also provides new insights on the terrestrial alteration of carbonaceous chondrites, with implications for the quantity of water in the asteroidal parent bodies of CI chondrites
Herrera, Contreras Cinthya Natalia. "How do the large-scale dynamics of galaxy interactions trigger star formation in the Antennae galaxy merger?" Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00800077.
Texto completoMonin, Jean-Louis. "Conception et réalisation d'une camera astronomique basée sur un détecteur infrarouge bidimensionnel : résultats astrophysiques". Phd thesis, Université Paris-Diderot - Paris VII, 1987. http://tel.archives-ouvertes.fr/tel-00725260.
Texto completoPartouche, David. "Analyse de l’assemblage de peptides amyloïdes bactériens". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX084/document.
Texto completoHfq is a pleiotropic bacterial protein that determines several phenotypic characteristics. Its main function is to facilitate responses to stresses that bacteria may encounter during environmental changes, mainly by using post-transcriptional genetic control. The protein, by its capacity to interact with RNA, in particular small non-coding RNA, enables a rapid regulation of gene expression. In addition, the protein also interacts with DNA and compacts it. From a structural point of view, the protein adopts an Sm-like fold, characterized by a toroidal oligomer formed by a continuous 30-stranded β-sheet. Besides its conserved N-terminal Sm domain, Hfq also possesses a C-terminal region (CTR) that can vary in size and sequence between bacteria. My PhD work focused on the analysis of this CTR region in Escherichia coli bacteria. Indeed, this region has the capacity to form an amyloid structure. This structural dynamic is related to the formation of self-assembled structures in vivo, in the proximity of the inner membrane and in the nucleoid.Using various physicochemical techniques (molecular microscopy, spectroscopy and infrared microscopy, circular dichroism and small angle X-ray scattering), my work consisted in characterizing the assembly of this region of Hfq, as well as the factors influencing its assembly (in particular, the presence of nucleic acids). A part of my work consisted in setting up an innovative correlative–imaging method to analyze the chemical and morphological signature of a single amyloid fibre. Finally, my work focused on the analysis of the effect of compounds that inhibit the aggregation of the amyloid structure, which could constitute a new way to develop a novel class of antibiotics
Dombrowski, Andrew G. "Frames within Themselves: Treating Visual Imagery as a Variable in IR". The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420621975.
Texto completoGeoffray, Hervé. "Etude et réalisation d'une caméra thermique destinée à un système d'optique adaptative : application à l'étude de la matière circumstellaire autour d'étoiles binaires pré-séquence principale". Phd thesis, Université Joseph Fourier (Grenoble), 1998. http://tel.archives-ouvertes.fr/tel-00724512.
Texto completoNoun, Manale. "Interaction agrégats-surface. Spectrométrie de masse par temps de vol et application analytique à des études sur des médicaments et sur la météorite Paris". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00906791.
Texto completoCeamanos, garcia Xavier. "Evaluation des performances de l'analyse statistique et physique d'images hyperspectrales de Mars. Application au capteur multi-angulaire CRISM". Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00648102.
Texto completoPrada, Pierre. "Apport de la spectroscopie vibrationnelle dans l'analyse plasmatique outissulaire, application en pathologies : spondyloarthrite, maladie de Crohn et cancer colorectal". Electronic Thesis or Diss., Reims, 2022. http://www.theses.fr/2022REIMP201.
Texto completoThe search for new generation markers is crucial for better patient management, both in terms of diagnosis and prediction of treatment response. Contrary to standard approaches targeting a specific molecular target, vibrational spectroscopy techniques give access to the global molecular constitution of a sample. The work of the BioSpecT unit has shown that these techniques can provide information on tissue organization that is complementary to conventional histology. For example, spectral imaging analysis of tissue samples from cancerous lesions (colon, skin, lung) can highlight the heterogeneity of tumor zones and finely characterize the stroma. An inflammatory component can also be distinguished from other structures. The objective of this thesis project is to exploit the information available by vibrational spectroscopy in the context of pathologies specific to the colon, in order to extract numerical markers charac terizing the physiopathological state of the lesions studied. The identification of such markers requires the comparison of spectroscopic data with clinical, histological, biological or pharmacological reference information. More precisely, we will focus on metastatic colon cancers with the objective of identifying predictive markers of response to chemotherapy. For the analyses, we will be able to benefit not only from human tissue samples (tumor library of the Reims University Hospital) but also from xenografts performed in mice in order to have material obtained according to more standardized protocols. In a complementary way, part of the research work could be carried out within the framework of a study on chronic inflammatory bowel diseases, by focusing the experiments on the characterization of inflammation by vibrational spectroscopy. This research will be carried out in collaboration with the Digestive Oncology Department (Pr O Bouché) of the Reims University Hospital, the Biopathology Laboratory (Pr A Marchal) of the Reims University Hospital and the INSERM U1113 IRFAC unit (Dr D Guenot) of Strasbourg
Margarit, Taulé Josep Maria. "Low-power CMOS digital-pixel Imagers for high-speed uncooled PbSe IR applications". Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/336094.
Texto completoLa present tesi doctoral descriu la recerca i el desenvolupament d'una nova tecnologia monolítica d'imatgeria infraroja de longitud d'ona mitja (MWIR), no refrigerada i de baix cost, per a usos industrials d'alta velocitat. El treball pren el relleu dels últims avenços assolits pel soci industrial NIT S.L. en el camp dels detectors MWIR de PbSe depositats en fase vapor (VPD), afegint-hi coneixement fonamental en la investigació de noves tècniques de disseny de circuits VLSI analògics i mixtes pel desenvolupament del dispositiu integrat de lectura unit al detector pixelat. Es parteix de la hipòtesi que, mitjançant l'ús de les esmentades tècniques de disseny, les tecnologies CMOS estàndard satisfan tots els requeriments operacionals del detector VPD PbSe respecte a connectivitat, fiabilitat, funcionalitat i escalabilitat per integrar de forma econòmica el dispositiu. La càmera PbSe-CMOS resultant ha de consumir molt baixa potència, operar a freqüències de kHz, exhibir bona uniformitat, i encabir els píxels actius CMOS de lectura en el pitch compacte del pla focal de la imatge, tot atenent a les particulars característiques del detector: altes relacions de corrent d'obscuritat a senyal, elevats valors de capacitat paràsita a l'entrada i dispersions importants en el procés de fabricació. Amb la finalitat de complir amb els requisits previs, es proposen arquitectures de sensors de visió de molt baix acoblament interpíxel basades en l'ús d'una matriu de pla focal (FPA) de píxels actius exclusivament digitals. Cada píxel sensor digital (DPS) està equipat amb mòduls de comunicació d'alta velocitat, autopolarització, cancel·lació de l'offset, conversió analògica-digital (ADC) i correcció del soroll de patró fixe (FPN). El consum en cada cel·la es minimitza fent un ús exhaustiu del MOSFET operant en subllindar. L'objectiu últim és potenciar la integració de les tecnologies de sensat d'imatge infraroja (IR) basades en PbSe per expandir-ne el seu ús, no només a diferents escenaris, sinó també en diferents estadis de maduresa de la integració PbSe-CMOS. En aquest sentit, es proposa investigar un conjunt complet de blocs funcionals distribuïts en dos enfocs paral·lels: - Dispositius d'imatgeria MWIR "Smart" basats en frames utilitzant noves topologies de circuit DPS amb correcció de l'FPN en guany i offset. Aquesta línia de recerca exprimeix el pitch del detector per oferir una programabilitat completament digital a nivell de píxel i plena funcionalitat amb compensació de la capacitat paràsita d'entrada i memòria interna de fotograma. - Dispositius de visió MWIR "Compact"-pitch "frame-free" en base a un novedós esquema d'integració analògica en el DPS i diferenciació temporal configurable, combinats amb protocols de comunicació asíncrons dins del pla focal. Aquesta estratègia es concep per permetre una alta compactació del pitch i un increment de la velocitat de lectura, mitjançant la supressió del filtrat digital intern i l'assignació dinàmica de l'ample de banda a cada píxel de l'FPA. Per tal d'independitzar la validació elèctrica dels primers prototips respecte a costosos processos de deposició del PbSe sensor a nivell d'oblia, la recerca s'amplia també al desenvolupament de noves estratègies d'emulació del detector d'IR i plataformes de test integrades especialment orientades a circuits integrats de lectura d'imatge. Cel·les DPS, dispositius d'imatge i xips de test s'han fabricat i caracteritzat, respectivament, en tecnologies CMOS estàndard 0.15 micres 1P6M, 0.35 micres 2P4M i 2.5 micres 2P1M, tots dins el marc de projectes de recerca amb socis industrials. Aquest treball ha conduït a la fabricació del primer dispositiu quàntic d'imatgeria IR d'alta velocitat, no refrigerat, basat en frames, i monolíticament fabricat en tecnologia VLSI CMOS estàndard, i ha donat lloc a Tachyon, una nova línia de càmeres IR comercials emprades en sistemes de control industrial, mediambiental i de transport en temps real.
Sharma, Vinay. "Simultaneous object detection and segmentation using top-down and bottom-up processing". Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196372113.
Texto completoPinelli, Francesca <1980>. "Cold cloud climatology over Europe and the Mediterranean during the warm season from Meteosat IR imagery". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3101/1/Pinelli_Francesca_tesi.pdf.
Texto completoPinelli, Francesca <1980>. "Cold cloud climatology over Europe and the Mediterranean during the warm season from Meteosat IR imagery". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3101/.
Texto completoHarajli, Zeinab. "Synthesis, characterisation and thermal evaluation of a new generation of metalised ceramic materials". Thesis, Lyon, 2022. http://www.theses.fr/2022LYSEI016.
Texto completoEfficient thermal management is often considered a key step towards a successful technological system. The fast removal of excess heat from electronic systems exposed to temperature extremes improves the reliability and prevents the premature failure of these systems. Nowadays, the usual approaches to evacuate heat and maintain the system at the desired temperature consist in using a semiconductor heat sink or a complex fan speed control system that relies on continuous temperature measurement. However, the optimization of a highly efficient semiconductor heat sink requires the control of diverse intrinsic and extrinsic properties at different scales because the macroscopic thermal flow and heat transport depend on microscopic vibrational properties. Besides, widespread use of highly efficient semiconductor heat sinks requires the ability to metalize them and form multilayer structures. Due to its high phonon group velocities, Aluminium Nitride (AlN) appears to be one of the best candidates for the manufacturing of efficient semiconductor heat sinks. In this PhD. thesis work, we intend to develop a new substrate technology Metal/AlN/Metal structures with high thermal diffusivity for integrated power systems for high-temperature applications (>300°C). This PhD. Aims at developing highly efficient, integrated and reliable power electronics technologies operating at high temperatures for automotive, aeronautic, and energy applications
Oelrich, B. D. "The design and characterisation of a low-cost micro-satellite thermal IR imager based on COTS technology". Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/842689/.
Texto completoDoule, Claude. "Amplification parametrique optique en regime femtoseconde et tomographie optique coherente : deux methodes d'imagerie proche infrarouge dans des milieux diffusants". Phd thesis, Université Paris Sud - Paris XI, 2000. http://pastel.archives-ouvertes.fr/pastel-00713989.
Texto completoChilcote, Jeffrey, Laurent Pueyo, Robert J. De Rosa, Jeffrey Vargas, Bruce Macintosh, Vanessa P. Bailey, Travis Barman et al. "1–2.4 μm Near-IR Spectrum of the Giant Planet β Pictoris b Obtained with the Gemini Planet Imager". IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623806.
Texto completoLiotta, Luca. "Analisi di una piccola missione satellitare per lo studio Phobos: sottosistema di telecomunicazione, link budget e payload ottico". Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Buscar texto completoSanders, Rindra. "Numérisation 3D d'objets transparents par polarisation dans l'IR et par triangulation dans l'UV". Thesis, Dijon, 2011. http://www.theses.fr/2011DIJOS039/document.
Texto completoTwo non-conventional methods for the 3D digitization of transparent objects via non-contact measurement are reported in this thesis. 3D digitization is a well acknowledged technique for opaque objects and various commercial solutions based on different measurement approaches are available in the market offering different types of resolution at different prices. Since these techniques require a diffused or lambertian surface, their application to transparent surfaces fails. Indeed, rays reflected by the transparent surface are perturbed by diverse inter-reflections induced by the refractive properties of the object. Therefore, in industrial applications like quality control, the transparent objects are powder coated followed by their digitization. However, this method is expensive and can also produce inaccuracies. Among the rare methods suggested in the literature, shape from polarization provides reliable results even though their accuracy had to be improved by coping with the inter-reflections. The two proposed solutions handle the extension of the existing methods to wavelengths beyond visible ranges: - shape from polarization in Infra Red (IR) range to deal with the above-mentioned inter-reflections; - scanning by Ultra Violet (UV) laser (based on triangulation scheme) to overcome the refraction problem that can be feasibly applied in industrial applications. The characteristic physical properties of transparent objects led us to explore the IR and UV ranges; since, transparent glass has strong absorption bands in the IR and UV ranges and therefore has opaque appearance. The first approach exploits the specular reflection of the considered object surface in IR and the second one exploits the fluorescence property of the object when irradiated with UV rays. Shape from polarization traditionally based on telecentric lenses had to be adapted with non-telecentric lenses to be used in the IR range. Thus, an approximation of the orthographic model is developed in this thesis while a validation method is implemented and integrated in the reconstruction process after Stokes parameters estimation, in order to improve the accuracy of the results. Some results of digitized objects are presented, which prove the feasibility of the shape from polarization method in the IR range to be used for transparent objects. A total of four configurations of the triangulation system are implemented in this thesis to exploit fluorescence produced by the UV laser scanning of the second approach. Experimental investigations aimed at characterizing the fluorescence are done. A specific fluorescence tracking method is carried out to deal with the inherent noise in the acquisitions. The uniqueness of the method relies on the criteria that are derived from the analysis of spectroscopic results. A validation method is made to optimize the configuration system while reducing the accuracy of reconstruction error. The results of some object digitization are presented with accuracies better than previously reported works
Gagnon, Marc-André. "Étude des propriétés de transport dans les hydrogels de curdlan". Thèse, 2009. http://hdl.handle.net/1866/3906.
Texto completoPolysaccharide hydrogels are biomaterials used as controlled drug delivery matrices and serve as model scaffolds for the study of many biological systems like bacterial biofilms and mucus. In every case, the transport of drugs or nutriments across a hydrogel matrix is of prime importance. Therefore, the study of transport properties in hydrogels is an important issue for many fields of application. In this work, curdlan, a neutral bacterial polysaccharide made of β-D-(1→3) glucose repeating units, is used as a model hydrogel. Aqueous suspensions of curdlan can form thermogels of different conformations depending on the incubation temperature. In situ characterization of the preparation of thermo-reversible (low-set) and thermo-irreversible (high-set) curdlan hydrogels was first carried out using variable temperature attenuated total reflection (ATR) Fourier transform infrared spectroscopy (FT-IR). The results allowed optimization of the gelling conditions leading to reproducible gel samples. Structural characterization of fully hydrated hydrogels, carried out by FT-IR imaging, environmental scanning electron microscopy (eSEM) and atomic force microscopy (AFM), allowed visualization of the different gel morphologies susceptible of influencing the diffusion of analytes in hydrogels. Our results show that both types of curdlan hydrogels have distinct microscopic architectures. The combination of pulsed field gradient (PFG) nuclear magnetic resonance (NMR) spectroscopy and NMR profiling allowed the study of self-diffusion and mutual diffusion on the same hydrogel system in similar experimental conditions. We showed that the diffusion of analytes in the gels is slower than in the aqueous solution. The diffusion experiments, carried out on a series of analytes of various sizes in both types of curdlan gels, show a decrease of the relative self-diffusion coefficient as a function of the analyte size. In addition, our results suggest that the equivalence between the self-diffusion and mutual-diffusion coefficients measured in the high-set curdlan gels is mainly due to the fact that the environment probed by the analytes during a self-diffusion experiment is representative of the one probed during a mutual-diffusion experiment. In such conditions, our results show that PFG NMR may present a valuable approach for the characterization of controlled drug release systems. Additional experiments show that the mutual-diffusion coefficient of dextran macromolecules is smaller than its self-diffusion coefficient in the same curdlan hydrogel. The difference between both transport rates is attributed to the different environment volumes probed by the analytes during the measurements. The similarities observed between the self-diffusion and mutual-diffusion coefficients, measured in both types of curdlan gels for all investigated analytes, suggest a limited influence of the microscopic gel architecture on its transport properties. It is therefore concluded that the interactions affecting the diffusion of the investigated analytes in the curdlan hydrogels lie at the molecular scale.
Svoboda, Jan. "Normalizace dat časových řad Landsat metodou IR-MAD". Master's thesis, 2019. http://www.nusl.cz/ntk/nusl-405244.
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