Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Synchrotron in situ imaging.
Rozprawy doktorskie na temat „Synchrotron in situ imaging”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Synchrotron in situ imaging”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Tan, Dongyue. "In situ ultrafast synchrotron X-ray imaging studies of the dynamics of ultrasonic bubbles in liquids". Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:12399.
Pełny tekst źródłaStreszczenie:
The research studies the highly dynamic and transient behaviour of ultrasonic bubbles in liquids of different physical properties, including water, silicone oil, and liquid metals. A novel ultrasound solidification apparatus as well as the special sample containers and the relevant control systems were designed, built and commissioned for this research. Systematic in situ experiments were conducted using this novel apparatus at the ultrafast synchrotron X-ray imaging (271,554 fps) beamline, the sector 32-ID-B of Advanced Photon Source (APS) and the high speed X-ray imaging beamline, I12 of Diamond Light Source (DLS) in 2011-2015. A huge amount of real-time images were obtained in this research, a procedure and the relevant in-house Matlab code were developed to analyse those images and extract the key information for understanding the highly dynamic behaviour of the nucleation, oscillation, implosion, coalescence of ultrasonic bubbles and bubble cloud. The ultrasound induced acoustic flows coupled with bubbles and particles were also investigated, and their effects on liquid-solid interface during the solidification of a Bi-8%Zn were analysed and quantified. The experiments were complemented by the modelling and simulations of the acoustic pressure field, the bubble dynamics using the classical Helmholtz Equation and Gilmore model, providing more quantitative understanding for the interactions of ultrasonic waves and bubbles with the liquids and the solid phases in the liquids. The key research findings are: For bubble implosion: For the first time, bubble implosion in liquid metal was captured in real-time and in situ. In both water and liquid Bi-8%Zn, compressed gas cores were found at the centre of the imploding bubble with shock waves emitted outwards from the centre. For bubble oscillations at quasi-steady state condition, the measured bubble radii agree well with the predictions made by Gilmore model for all liquids studied in this research. For bubble coalescence, the time needed for liquid Bi-8%Zn cannot be predicted using either the no-slip or the free interface model. A new power law model is developed and the prediction made using this new model agrees well with the experiments. For the first time, in metal alloys, the in situ and real-time studies proved that the ultrasonic bubbles and the acoustic flows are capable of fracturing and detaching the solid phases from the liquid-solid interface. Temperature fluctuations caused by applying ultrasound in Bi-8%Zn during solidification is capable of detaching the solid phases from the liquid-solid interface. However, it is less important and slower than acoustic flows and ultrasonic bubbles. Ultrasound power is a dominant parameter for the interactions of ultrasonic bubbles, acoustic flows, temperature fluctuations with liquid-solid interface.
2
Koc, Hicran. "Infrared chemical imaging of germinated wheat : early nondestructive detection and microspectroscopic imaging of kernel thin cross sections in Situ". Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/512.
Pełny tekst źródła
3
Riberi-Béridot, Thècle. "In situ characterization by X-ray synchrotron imaging of the solidification of silicon for the photovoltaic applications : control of the grain structure and interaction with the defects and the impurities". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0412/document.
Pełny tekst źródłaStreszczenie:
Au cours de cette thèse, nous avons étudié in situ la solidification du silicium à l’aide de l'imagerie X-synchrotron. Les deux techniques utilisées lors de la solidification sont la radiographie et la diffraction de Bragg, elles permettent de caractériser: la dynamique des mécanismes de croissance, la cinétique de croissance, la nucléation et la compétition de grains, la déformation du réseau cristallin et les champs de contraintes liés aux dislocations. Ces observations sont combinées avec des caractérisations ex situ pour étudier l'orientation cristallographique, les déformations du réseau cristallin ainsi que les concentrations d'impuretés légères telles que le carbone et l'oxygène.La complémentarité de ces techniques permet d'étudier et de mieux comprendre : les phénomènes physiques liés à la formation de la structure de grain finale. Les résultats concernant la cinétique de croissance de l'interface solide-liquide et des facettes {111}, l'établissement de la structure de grain, l'importance du maclage, l'effet des impuretés légères, le champ de contrainte lié à la croissance et la compétition de grains et les dislocations sont discutés dans le manuscritDuring this thesis, we studied in situ the solidification of silicon with X-synchrotron imaging. The two techniques used during solidification are radiography and Bragg diffraction and they allow characterizing: dynamic growth mechanisms, growth kinetics, grain nucleation and competition, lattice deformation and dislocation related strain fields. These observations are combined with ex situ characterizations to study the crystallographic orientation, the deformations of the crystal lattice as well as the concentrations of light impurities such as carbon and oxygen. The complementarity of these techniques makes it possible to study and to better understand: the physical phenomena related to the formation of the final grain structure. Results concerning the growth kinetics of the solid-liquid interface and of the {111} facets, the establishment of the grain structure, the importance of twinning, the effect of light impurities, the strain field related to growth and grain competition and dislocations are discussed in the manuscript
4
Baier, Sina, Christian D. Damsgaard, Maria Scholz, Federico Benzi, Amélie Rochet, Robert Hoppe, Torsten Scherer i in. "In Situ Ptychography of Heterogeneous Catalysts using Hard X-Rays: High Resolution Imaging at Ambient Pressure and Elevated Temperature". Cambridge University Press, 2016. https://tud.qucosa.de/id/qucosa%3A70694.
Pełny tekst źródłaStreszczenie:
A new closed cell is presented for in situ X-ray ptychography which allows studies under gas flow and at elevated temperature. In order to gain complementary information by transmission and scanning electron microscopy, the cell makes use of a Protochips E-chipTM which contains a small, thin electron transparent window and allows heating. Two gold-based systems, 50 nm gold particles and nanoporous gold as a relevant catalyst sample, were used for studying the feasibility of the cell. Measurements showing a resolution around 40 nm have been achieved under a flow of synthetic air and during heating up to temperatures of 933 K. An elevated temperature exhibited little influence on image quality and resolution. With this study, the potential of in situ hard X-ray ptychography for investigating annealing processes of real catalyst samples is demonstrated. Furthermore, the possibility to use the same sample holder for ex situ electron microscopy before and after the in situ study underlines the unique possibilities available with this combination of electron microscopy and X-ray microscopy on the same sample.
5
Cheng, Yin [Verfasser], i Ingo [Akademischer Betreuer] Krossing. "In situ synchrotron radiation computed laminography for materials failure analysis = In-situ Synchrotron-Laminographie für Materialfehleranalyse". Freiburg : Universität, 2013. http://d-nb.info/1123479097/34.
Pełny tekst źródła
6
Duxbury, Dominic Mark. "Novel X-ray imaging detectors". Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243037.
Pełny tekst źródła
7
Herron, Maura Ethna. "In-situ studies of electrode surfaces using synchrotron X-ray radiation". Thesis, University of Southampton, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316425.
Pełny tekst źródła
8
Joita, Pacureanu Alexandra. "Imaging the bone cell network with nanoscale synchrotron computed tomography". Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00778408.
Pełny tekst źródłaStreszczenie:
The osteocytes are the most abundant and longest living bone cells, embedded in the bone matrix. They are interconnected with each other through dendrites, located in slender canals called canaliculi. The osteocyte lacunae, cavities in which the cells are located, together with the canaliculi form a communication network throughout the bone matrix, permitting transport of nutrients, waste and signals. These cells were firstly considered passive, but lately it has become increasingly clear their role as mechanosensory cells and orchestrators of bone remodeling. Despite recent advances in imaging techniques, none of the available methods can provide an adequate 3D assessment of the lacuno-canalicular network (LCN). The aims of this thesis were to achieve 3D imaging of the LCN with synchrotron radiation X-ray computed tomography (SR-CT) and to develop tools for 3D detection and segmentation of this cell network, leading towards automatic quantification of this structure. We demonstrate the feasibility of parallel beam SR-CT to image in 3D the LCN (voxel~300 nm). This technique can provide data on both the morphology of the cell network and the composition of the bone matrix. Compared to the other 3D imaging methods, this enables imaging of tissue covering a number of cell lacunae three orders of magnitude greater, in a simpler and faster way. This makes possible the study of sets of specimens in order to reach biomedical conclusions. Furthermore, we propose the use of divergent holotomography, to image the ultrastructure of bone tissue (voxel~60 nm). The image reconstruction provides phase maps, obtained after the application of a suitable phase retrieval algorithm. This technique permits assessment of the cell network with higher accuracy and it enables the 3D organization of collagen fibres organization in the bone matrix, to be visualized for the first time. In order to obtain quantitative parameters on the geometry of the cell network, this has to be segmented. Due to the limitations in spatial resolution, canaliculi appear as 3D tube-like structures measuring only 1-3 voxels in diameter. This, combined with the noise, the low contrast and the large size of each image (8 GB), makes the segmentation a difficult task. We propose an image enhancement method, based on a 3D line filter combined with bilateral filtering. This enables improvement in canaliculi detection, reduction of the background noise and cell lacunae preservation. For the image segmentation we developed a method based on variational region growing. We propose two expressions for energy functionals to minimize in order to detect the desired structure, based on the 3D line filter map and the original image. Preliminary quantitative results on human femoral samples are obtained based on connected components analysis and a few observations related to the bone cell network and its relation with the bone matrix are presented.
9
Pagot, Elodie. "Quantitative comparison between two phase contrast techniques for mammography : diffraction enhanced imaging (DEI) and phase propagation imaging (PPI)". Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE10016.
Pełny tekst źródłaStreszczenie:
Les techniques de contraste de phase constituent une nouvelle approche de l'imagerie aux rayons X, fournissant l'information sur la phase et l'atténuation des rayons X. Elles sont d'un grand intérêt pour des applications médicales car elles peuvent explorer des objets à faible Z avec un meilleur contraste et une dose réduite comparée à la radiographie standard. Une comparaison quantitative des deux techniques rayonnement synchrotron de contraste de phase, en vue de futures applications en mammographie : le Diffraction Enhanced Imaging (DEI) et le Phase Propagation Imaging (PPI). Les modes radiographiques et tomographiques sont étudiés à différentes énergies. Les techniques sont évaluées par rapport à leur qualité d'image et l'information quantitative qu'elles fournissent. Une nouvelle approche statistique en DEI permet la séparation des effets d'absorption, réfraction et diffusion. La distribution 3D de la densité massique de tissu mamaire est reconstruite dans les deux casPhase sensitive techniques constitute à new approach for X-ray imaging by providing both the phase and attenuation information. They are of particular interest for medical applications as they enable subjects composed of low Z materials to be explored with improved contrast and reduced dose compared to standard absorption radiography. A quantitative comparison is made between two synchrotron radiation based phase contrast techniques, "Phase Propagation Imaging" and "Diffraction Enhanced Imaging" (DEI), in view for future application in mammography. Both radiographic and tomographic modalities were investigated, in the hard X-ray range. The techniques were assessed with respect to their image quality and the yield of quantitative information. A new statistical technique applied to DEI allows the separation of absorption, refraction and scattering information. The 3-dimensional mass density distribution of a breast tissue sample is reconstructed in both DEI and PPI cases
10
McRae, Reagan. "Investigating metal homeostasis in mammalian cells using high resolution imaging techniques". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41197.
Pełny tekst źródłaStreszczenie:
The primary aim of the work presented in this thesis is to elucidate novel information regarding the uptake, storage, distributions, and functions of both copper and zinc in mammalian cells by predominantly using a combination of the high resolution imaging modalities, synchrotron radiation X-ray fluorescence microscopy (SXRF) and standard fluorescence imaging. Results from studies using cell permeable, metal ion selective fluorescent probes suggested the presence of labile pools of copper and zinc localized within the mitochondria and Golgi apparatus. Furthermore, SXRF imaging of a cell line defective in the copper transporter, Atox1, revealed intriguing differences in the Cu distribution of Atox1-/- cells compared to the corresponding wild-type cells. Finally, spatially well-resolved SXRF elemental maps of single, adherent mouse cells revealed remarkable changes in the distributions of both zinc and copper as the cells progressed through the cell cycle. Taken together, findings suggested major roles for copper and zinc within a native biological setting.
11
Schönau, Kristin Alice. "In situ synchrotron diffraction of lead zirconatetitanate at its morphotropic phase boundary". Aachen Shaker, 2007. http://d-nb.info/988311704/04.
Pełny tekst źródła
12
Gallagher, Mark Edward. "In-situ synchrotron X-ray scattering studies of the electrode / electrolyte interface". Thesis, University of Liverpool, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415746.
Pełny tekst źródła
13
Pile, Katharine. "Synchrotron tomographic energy-dispersive diffraction imaging of static and dynamic systems". Thesis, Birkbeck (University of London), 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440493.
Pełny tekst źródła
14
Zhou, Tao. "In situ synchrotron X-ray scattering of SiGe NWs : growth, strain and bending". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAY084.
Pełny tekst źródłaStreszczenie:
Ce travail résume les résultats d'études de la croissance in situ de nanofils (NFs) SiGe par UHV-CVD à l'aide des techniques de diffusion et de diffraction des rayons X (RX) synchrotron sur la ligne de lumière BM32 à l'ESRF.Les conditions d'élaboration de NFs Si, Ge, SiGe dans notre bâti sont d'abord présentées. Les études in situ à l'aide de RX durant la croissance sont ensuite décrites. La longueur des NFs, leur taille, leur espacement, leur facetage ainsi que l'angle conique sont déterminés en temps réel. Des changements de forme de la goutte liquide aussi ont été clairement observés dans les premiers stades de la croissance. Une phase AuGe métastable à l'interface catalyseur-substrat a été identifiée. Sa formation pourrait être décisive pour la croissance sous-eutectique de NFs de Ge.La relaxation des contraintes dans des NFs coeur-coquille de Si-Ge est ensuite présentée. La composition et la déformation ont été déterminée in situ par diffusion anomale des RX, en fonction de la quantité de Ge deposé et de la durée du recuit. L'influence de la taille des NFs et de la température de croissance de la coquille ont aussi été étudiée.Enfin, des résultats sur la courbure in situ de NFs sont présentés. La courbure est induite par le dépôt d'un second matériau sur un côté des NFs. La déformation et la contrainte ont été déterminées par une combinaison de suivi de la position d'un pic de Bragg, de simulation et d'ajustement de l'intensité, et de calculs d'élasticité classiques. La courbure induite par le dépôt de Ge à 220°C est principalement déterminée par la contrainte de désaccord de maille, qui évolue presque linéairement avec l'épaisseur du film Ge. La courbure induite par le dépôt de Ge à la température ambiante (TA) se trouve principalement déterminée par la contrainte de surface, qui évolue progressivement de la tension à la compression pour une épaisseur de Ge plus grande. Pour le suivi de courbure en temps réel, nous avons mise au point une technique de mesures stationnaires avec un détecteur 2D. Elle a permis de mettre en évidence plusieurs changements de signe lors de dépôts d'Au et Ge à TAThis work summarizes the progress made on the BM32 beamline at the ESRF over the past 4 years since the launch of the CVD project, which was aimed at studying the in situ growth of SiGe nanowires, using synchrotron X-ray scattering techniques.Results on the growth of Si and Ge NWs are first presented. The NWs length, size, spacing, facet morphology and their tapering angle are determined in real time with X-ray techniques. Special attention was paid to the very early stage of growth where changes in the shape of the AuSi liquid droplet were clearly observed. We also found clues indicating the presence of a metastable AuGe phase at the catalyst-substrate interface, the formation of which may be crucial to the sub-eutectic growth of Ge NWs.Strain relaxation in Si-Ge core-shell NWs is presented next. The composition and strain were determined in situ as a function of the Ge overgrowth amount and of the annealing time, using anomalous X-ray scattering techniques. Their dependence on the NW size and on the shell growth temperature was also studied.Finally, results on the in situ bending of as-grown NWs are shown. The bending was induced by depositing a second material on one side of the NWs. The strain and stress were determined by a combination of Bragg peak tracking, intensity simulation plus fitting and classic elasticity calculations. The bending induced by Ge deposition at 220°C is found to be mainly driven by the misfit stress, which scales almost linearly with Ge film thickness. On the other hand, the bending induced by Ge deposition at RT is found to be mainly driven by the surface stress, which evolves gradually from tensile to compressive for larger Ge thickness. A new technique was also devised which makes it possible to follow qualitatively the bending process. The NWs were seen dancing back and forth with increasing amount of deposition as revealed by real time stationary measurements with a 2D detector
15
Cai, Biao. "In situ synchrotron tomographic quantification of semi-solid properties of aluminum-copper alloys". Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/in-situ-synchrotron-tomographic-quantification-of-semisolid-properties-of-aluminumcopper-alloys(60c222d0-7e70-4a1e-9ed4-75b8f559d5de).html.
Pełny tekst źródłaStreszczenie:
Semi-solid deformation mechanisms are important in a range of manufacturing and natural phenomena, which range from squeeze casting to magma flows. In this thesis, using high speed synchrotron X-ray tomography and a bespoke precision thermo-mechanical rig, a four dimensional (3D plus time) quantitative investigation was performed to study the mechanical / rheological behavior of semi-solid Al-Cu alloys. Various deformation techniques, namely, isothermal semi-solid compression, extrusion and indentation were used. The time-resolved dynamic 3D images were analyzed with the help of novel image quantification techniques including digital volume correlation and image-based simulations of fluid flow. The quantified dynamics at a microstructural scale was then linked with macroscopic mechanical properties. The qualitative and quantitative analyses revealed a range of important semi-solid micromechanical mechanisms including the occurrence and effects of dilatancy, associated liquid flow through the equiaxed microstructure, intra-dendritic deformation, and strain localization during semi-solid deformation, not only shedding new insights into the mechanisms of deformation-induced solidification defect formation (solute segregation, porosity and hot tearing) of semi-solid alloys at both a macroscopic and microscopic level, but also providing benchmark cases for semi-solid deformation models and theories. The experimental methodology, techniques and analysis procedures developed in this thesis are generic in nature and can be applied to a wide range of research fields.
16
Dirand, Laura. "Fluage à haute température d’un superalliage monocristallin : expérimentation in situ en rayonnement synchrotron". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL079N/document.
Pełny tekst źródłaStreszczenie:
Les superalliages monocristallins à base de nickel sont utilisés en aéronautique pour les aubes de turbines. Cette étude est consacrée à la modélisation du comportement en fluage du superalliage monocristallin AM1 après mise en radeaux, au cours d’essais isothermes à contrainte variable. Des diffractogrammes (200) ont été obtenus in situ par diffractométrie trois axes en rayonnement synchrotron, à haute température (950-1150°C) pour des paliers de contrainte entre 0 et 300MPa. Pour chaque phase, les déformations élastiques se déduisent de la position des pics et les contraintes, déformations plastiques et vitesses de déformation sont obtenues par la mesure du désaccord paramétrique, en utilisant un modèle composite en série. Ces résultats sont combinés à une caractérisation post mortem en microscopie électronique : morphologie des phases, densité et nature des dislocations. La mesure in situ du désaccord paramétrique donne accès à la densité instantanée de dislocations aux interfaces y/y’. Dans la phase ylors d’incréments de la contrainte appliquée, la contrainte de Von Mises augmente, puis se relaxe jusqu’à une contrainte seuil. Cette contrainte est en accord avec la contrainte d’Orowan et les largeurs des couloirs mesurées post mortem. La déformation plastique de la phase y’ est produite par montée de dislocations de vecteur de Burgers perpendiculaire à l’axe de traction sous l’action de la seule contrainte transverse et contrôlée par l’entrée de dislocations depuis les interfaces. Une simulation des pics de diffraction permet de reproduire l’évolution de leur largeur en fonction de la nature et de la répartition des dislocations aux interfaces et dans la phase y'Nickel-based superalloys are used in aeronautics for turbine blades. This study aims at modelling the creep behaviour of single-crystalline AM1 superalloy with a rafted γ/γ’ microstructure during isothermal tests under variable applied stresses. (200) diffraction profiles are obtained with a triple crystal diffractometer and high energy synchrotron radiation at high temperature (950-1150°C) with an applied stress varying between 0 and 300 MPa. For each phase, the elastic strain is deduced from the peaks’ positions and the stress, plastic strain rate from the lattice mismatch, assuming a model lamellar composite material. Post mortem characterizations by electronic microscopy completes the results: morphology of each phase, dislocations densities and nature. The measurement of lattice mismatch leads to an in situ estimation of the dislocations’ density at the γ/γ’ interfaces. For the γ phase, during successive jumps of the applied stress, the Von Mises stress increases and then relaxes down to a threshold stress. This stress is in agreement with Orowan stress deduced from the post mortem measurements of the γ channels’ width. Plastic strain of the γ' phase is produced by climb of dislocations with Burgers’ vectors perpendicular to the tensile axis under the mere transversal stress and is controlled by the entrance of dislocations into the rafts from the interfaces. The distribution of elastic strains was simulated by assuming two main contributions: dislocations at the γ/γ’ interfaces and within the γ’ rafts. The simulation reproduces the absolute magnitude of the peaks’ width, as well as their increase with dislocation densities
17
Kareh, Kristina Maria. "In situ synchrotron tomography of granular deformation in semi-solid Al-Cu alloys". Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/29367.
Pełny tekst źródłaStreszczenie:
Optimising casting routes involving semi-solid deformation such as semi-solid processing and high-pressure die casting requires a fundamental understanding of the globule-scale mechanisms behind the macroscopic rheological behaviour. This thesis uses time-resolved 3D imaging to directly observe and measure semi-solid alloy deformation from a microstructural perspective. Under isothermal conditions and constant strain rates, deformation mechanisms both at the crystal scale and at the specimen scale were identified during deformation in globular Al-Cu alloys at 64-93% solid. Imaging and quantifying these mechanisms has led to the emergence of a refined understanding of semi-solid deformation based on granular material concepts. It is shown that globularised crystals (above fs > 60%) exclusively rearrange as individual grains during parallel plate compression and backward extrusion at low strain rates. Crystal-crystal interactions are identified for the two loading modes and are not accompanied by plastic deformation of the individual crystals during acquisition. The ubiquitous grain rearrangement is coupled with shear-induced dilation of the solid assembly, whereby the crystals push each other apart in order to accommodate the increasing strain. It is also shown that, for specimens lacking a liquid reservoir, shear-induced dilation causes menisci to be pulled into the specimen from the surface and additionally, at high solid fractions, internal pores to grow. The origins of cracking during semi-solid processing are explored in a granular framework and linked to the shear-induced dilation associated with the solid assembly which increases the initial width of the liquid channels between the grains. Finally, the discrete grain analysis is coupled with the bulk mechanical results to explore the shape of the stress-strain curve and relate it to the imaged and quantified behaviours. All solid fractions tend to the same final stress, hinting at the possibility of a critical state analogous to that in soil mechanics, although fully testing this hypothesis requires varying the confining pressure.
18
Clède, Sylvain. "From metal carbonyls to single core multimodal probes for imaging". Paris 6, 2013. http://www.theses.fr/2013PA066576.
Pełny tekst źródłaStreszczenie:
Les métaux carbonyles, de par leurs propriétés vibrationnelle et de luminescence, sont des candidats idéaux afin de réaliser une imagerie bimodale cellulaire. Le fil conducteur de cette thèse a été la mise au point, l’étude et l’utilisation d’un cœur rhénium tris-carbonyle [LRe(CO)3X] (L = pyridyl-1,2,3-triazole et X = Cl-) dit SCoMPI pour « Single Core Multimodal Probe for Imaging », combinant les modalités IR et de luminescence sur une structure moléculaire unique, stable en milieu biologique. Des cartes IR et de luminescence ont été réalisées sur des cellules incubées avec un dérivé SCoMPI. Leur correspondance a démontré l’intégrité en milieu cellulaire et la pertinence en tant qu’agent bimodal d’une telle unité. Il était alors possible de l’envisager comme une plateforme de spectroscopie corrélative greffable. Une première application à la détection d’un dérivé œstrogénique a mis en évidence tout son potentiel pour le traçage de molécules. L’étude approfondie de l’influence de substituants du ligand L sur la pénétration cellulaire de sondes SCoMPI a permis de mieux comprendre les paramètres influant sur leur internalisation. Le suivi IR/luminescence en temps réel de sa translocation a montré l’intérêt de ces objets pour l’imagerie de cellules vivantes. Parallèlement à ces travaux, nous avons confirmé qu’il est pertinent de considérer des rapports de bandes IR en vue de détecter des organites, sans recours à un marquage exogène. Grâce à ses nombreux atouts (faible énergie mise en jeu, pénétration accrue, signature propre à chaque fonction chimique), la spectroscopie IR est amenée à être davantage utilisée pour la résolution de problématiques biologiquesMetal carbonyls are ideal candidates for bimodal bio-imaging due to their appropriate vibrational and luminescence properties. The main focus of this work has been the development, the study and the use of a rhenium tris-carbonyl unit [LRe(CO)3X] (L = pyridyl-1,2,3-triazole, X = Cl-), named SCoMPI for “Single Core Multimodal Probe for Imaging”, combining IR and luminescent modalities on a unique molecular moiety, robust in biological media. Since IR and luminescent sub-cellular mappings of the first SCoMPI compound were consistent, its integrity and relevance as a bimodal imaging agent were demonstrated. A first bio-application to track an estrogen derivative showed that SCoMPIs have a great potential as luminescent and vibrational tags. The in-depth study of the influence of pendant groups on its cellular uptake allowed for a better understanding of the parameters involved. Successful bimodal live-cell imaging highlighted that SCoMPIs could be used as imaging agents in living cells. In parallel, the analysis of minute changes in intracellular spectra by synchrotron-based IR spectromicroscopy confirmed the relevance of considering specific IR band-ratios to detect organelles, with no need of exogenous staining. Thanks to its multiple assets (low energy involved, deep penetration, specific signature of each chemical function), the IR spectroscopy tends to be more used in the future for biological applications
19
Ghahari, Seyed Majid. "In situ synchrotron x-ray characterisation and modelling of pitting corrosion of stainless steel". Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3269/.
Pełny tekst źródłaStreszczenie:
Pit propagation in stainless steels under electrochemical control was investigated using in situ synchrotron X-ray microtomography, which was used to confirm that the lacy covers commonly found for pits in stainless steels grow through perforation of the metal surface by upward growth of rapidly dissolving lobes from the main pit. In situ synchrotron X-ray radiography has been used to observe the evolution of 2D pits growing at the edge of stainless steel foils under electrochemical control in chloride solutions. Pit growth shape, kinetics and stability under current and potential control at various bulk chloride concentrations have been studied. It was found that the pit depth tends to grow under diffusion control, whereas lateral development is influenced by solution conductivity. The impact of the perforated cover on the pit growth and stability was examined and its formation was found to be similar to the observations from 3D by X-ray microtomography. A method for extracting the key dissolution kinetic parameters from radiographs has been developed. The local anodic current density along the boundary of a pit was directly measured from the rate of advance of the pit into the metal. Then the local metal ion concentration and potential drop inside the pit cavity was back-calculated using transport equations and the requirement to maintain charge neutrality, establishing the relationship between local current density, interfacial potential and metal ion concentration in the solution. The predictive model for pit propagation in stainless steel developed by Laycock and co-workers was examined, its sensitivity to key growth parameters was evaluated, and a modified version of the model was developed based on the kinetic parameters extracted from the radiographic measurements.
20
Matsouli, Ioanna. "Study of magneto-acoustic effects in FeBOâ†3 by synchrotron radiation diffraction imaging". Thesis, University of Warwick, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310013.
Pełny tekst źródła
21
Baksh, Peter. "Ptychographic imaging of real biological samples using a high harmonic and synchrotron source". Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/404697/.
Pełny tekst źródłaStreszczenie:
Visualisation of nano structure is essential for rapidly evolving fields such as lithography, and to gain a greater understanding of mechanisms behind biological processes. This thesis focuses on using coherent diffraction imaging methods to resolve fine biological structures using a high harmonic generation source and a synchrotron source. The majority of work is focused on developing imaging using the ptychography technique using extreme ultraviolet radiation (EUV) at the University of Southampton. The state of the high harmonic generation imaging beam line is first improved. Flux, stability, and coherence have all been improved in order to meet the required beam characteristics for ptychography imaging. We present published experimental data that shows the first high resolution transmission polychromatic ptychography result from a high harmonic source. To the best of our knowledge we also show the first near field ptychography reconstruction on a high harmonic source. The very first images of real biological samples (chromosomes and hippocampal neurons) using high harmonic generation ptychography are presented. We can achieve 54nm resolution over 100 μm field of view of weakly scattering samples imaging both phase and amplitude. Our EUV microscope is compared to data collected using an established hard X-ray synchrotron source, where it is found far more information can be extracted from the inexpensive table-top source at the University of Southampton.
22
Coan, Paola. "Development and application of the analyzer-based imaging technique with hard synchrotron radiation". Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10075.
Pełny tekst źródłaStreszczenie:
CETTE THESE A UN DOUBLE OBJECTIF: D'UNE PART IL S'AGIT DE L'APPLICATION DE L'IMAGERIE X PAR CONTRASTE DE PHASE (AVEC CRISTAL ANALYSEUR) POUR L'ETUDE DES CARTILAGES, OS ET IMPLANTS A L'AIDE DU RAYONNEMENT SYNCHROTRON ET D'AUTRE PART CE TRAVAIL CONTRIBUE AU DEVELOPPEMENT, THEORIQUE ET EXPERIMENTAL, DES TECHNIQUES D'IMAGERIE PAR CONTRASTE DE PHASE. PLUSIEURS ECHANTILLONS HUMAINS POST MORTEM ONT ETE IMAGES PAR UNE TECHNIQUE DE CONTRASTE DE PHASE UTILISANT UN CRISTAL ANALYSEUR (ABI). L'ETUDE COMPREND L'IMAGERIE PAR PROJECTION ET TOMOGRAPHIQUE D'ARTICULATIONS DE HANCHE, ORTEIL ET CHEVILLE. LES IMAGES PAR ABI ONT ETE CONFRONTEES A CELLES OBTENUES PAR DES TECHNIQUES CONVENTIONNELLES: RADIOGRAPHIE, TOMODENSITOMETRIE, ECHOGRAPHIE, IMAGERIE PAR RESONANCE MAGNETIQUE ET A DE L'HISTOLOGIE, QUI SERT DE REFERENCE. LES RESULTATS MONTRENT QUE SEULE L'IMAGERIE PAR ABI PERMET DE VISUALISER OU ESTIMER CORRECTEMENT LE STATUT PATHOLOGIQUE PRECOCE DU CARTILAGE. LA CROISSANCE DE L'OS APRES IMPLANTS A AUSSI ETE ETUDIEE SUR LES ECHANTILLONS POST MORTEM DE MOUTON : LA TECHNIQUE D'IMAGERIE PAR ABI PERMET DE FAIRE LA DIFFERENCE ENTRE UNE BONNE GUERISON ET UN RECUPERATION INCOMPLETE DE L'OS. DES EXPERIENCES PIONNIERES, lN VIVO, REALISEES AVEC DES COCHONS DE GUINEE ONT EGALEMENT ETE MENEES AVEC SUCCES, CONFIRMANT AINSI L'UTILISATION POSSIBLE DE LA TECHNIQUE POUR LE SUIVI DES MALADIES AFFECTANT LES ARTICULATIONS, L'ASSIMILATION DES IMPLANTS OU ENCORE L'ETUDE DE L'EFFICACITE DE MEDICAMENTS. EN CE QUI CONCERNE LE DEVELOPPEMENT DES TECHNIQUES PAR CONTRASTE DE PHASE, DEUX OBJECTIFS ONT ETE ATTEINTS. POUR LA PREMIERE FOIS, IL A ETE DEMONTRE EXPERIMENTALEMENT QUE LES TECHNIQUES D'IMAGERIE UTILISANT LE CONTRASTE DE PHASE PAR ABI ET PAR PROPAGATION (PPI) PEUVENT ETRE COMBINEES POUR CREER DES IMAGES AYANT DES CARACTERISTIQUES PROPRES (IMAGERIE HYBRIDE HI). DEUXIEMEMENT, UNE NOUVELLE CONFIGURATION EXPERIMENTALE SIMPLIFIEE, POUR L'ACQUISITION D'IMAGES PROCHES DE CELLES OBTENUES PAR ABI OU HI, EST PROPOSEE ET TESTEE. ENFIN, LES DEUX TECHNIQUES D'IMAGERIE PAR ABI OU HI ONT ETE ETUDIEES D'UN POINT DE VUE THEORIQUE AVEC UN CODE DE SIMULATION ORIGINAL QUI EST CAPABLE DE REPRODUIRE LES RESULTATS EXPERIMENTAUXTHE OBJECTIVE OF THIS THESIS IS TWOFOLD: FROM ONE SI DE THE APPLICATION OF THE ANALYSER-BASED X-RAY PHASE CONTRAST IMAGING TO STUDY CARTILAGE, BONE AND BONE IMPLANTS USING THE 1017 AND 1019 ESRF SYNCHROTRON RADIATION SOURCES AND ON THE OTHER TO CONTRIBUTE TO THE DEVELOPMENT OF THE PHASE CONTRAST TECHNIQUES FROM THE THEORETICAL AND EXPERIMENTAL POINT OF VIEW. SEVERAL HUMAN SAMPLES HAVE BEEN STUDIED lN VITRO USING THE ANALYSER BASED IMAGING (ABI) TECHNIQUE. EXAMINATION INCLUDED PROJECTION AND COMPUTED TOMOGRAPHY IMAGING AND 3D VOLUME RENDERING OF HIP, BIG TOE AND ANKLE ARTICULAR JOINTS. X-RAY ABI IMAGES HAVE BEEN CRITICALLY COMPARED WITH THOSE OBTAINED WITH THE CONVENTIONAL TECHNIQUES, INCLUDING RADIOGRAPHY, COMPUTED TOMOGRAPHY, ULTRASOUND, MAGNETIC RESONANCE AND HISTOLOGY, THE LATTER TAKEN AS GOLO STANDARD. RESUL TS SHOW THAT ONL Y ABI IMAGING WAS ABLE TO EITHER VISUALIZE OR CORRECTLY ESTIMATE THE EARLY PATHOLOGICAL STATUS OF THE CARTILAGE. THE STATUS OF THE BONE INGROWTH lN SHEEP IMPLANTS HAVE ALSO BEEN EXAMINED lN VITRO: ABI IMAGES PERMITTED TO CORRECTL Y DISTINGUISH BETWEEN GOOD AND INCOMPLETE BONE HEALING. PIONEERING INVIVO ABlON GUINEA PIGS WERE ALSO SUCCESSFULL Y PERFORMED, CONFIRMING THE POSSIBLE USE OF THE TECHNIQUE TO FOLLOW UP THE PROGRESSION OF JOINT DISEASES, THE BONE/METAL INGROWTH AND THE EFFICACY OF DRUGS TREATMENTS. AS PART OF THE DEVELOPMENT OF THE PHASE CONTRAST TECHNIQUES, TWO OBJECTIVES HAVE BEEN REACHED. FIRSTL Y, IT HAS BEEN EXPERIMENTALL Y DEMONSTRATED FOR THE FIRST TIME THAT THE ABI AND THE PROPAGATION BASED IMAGING (PBI) CAN BE COMBINED TO CREATE IMAGES WITH ORIGINAL FEATURES (HYBRID IMAGING, HI). SECONDL Y, IT HAS BEEN PROPOSED AND EXPERIMENTALL Y TESTED A NEW SIMPLIFIED SET-UP CAPABLE TO PRODUCE IMAGES WITH PROPERTIES SIMILAR TO THOSE OBTAINED WITH THE ABI TECHNIQUE OR HI. FINALL Y, BOTH THE ABI AND THE HI HAVE BEEN THEORETICAL STUDIED WITH AN INNOVATIVE, WAVE-BASED SIMULATION PROGRAM, WHICH WAS ABLE TO CORRECTL Y REPRODUCE EXPERIMENTAL RESUL TS
23
Strusevich, Dmitry. "Development of in-situ synchrotron X-ray powder diffraction techniques for studies of catalytic systems". Thesis, Birkbeck (University of London), 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497909.
Pełny tekst źródła
24
Huseynli, Fakhriyya. "The process of MA-XRF data for spectroscopy imaging in cultural heritage". Master's thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/29943.
Pełny tekst źródłaStreszczenie:
Scanning macro-X-ray fluorescence analysis (MA-XRF) is rapidly being established as a technique for the investigation of historical paintings. The elemental distribution images acquired by this method allow the visualization of hidden paint layers and thus, provide insight into the artist's creative process and the painting's conservation history.
As a non-destructive instrument MA-XRF and analyzing software PyMca will be used to identify, also to study painting from private collection in Italy. The use of MA-XRF to tentatively predict pigments has an important advantage, its application provides the undamaged and low cost survey of large areas in the painting. The method was proved powerful and useful, capable of efficiently determining the composition and structure of the investigated object in a total safe approach. Nevertheless, for a more throughout evaluation and a better estimation of the pigment composition, it has been demonstrated that, the use of complementary analytical techniques is required
25
FEDON, CHRISTIAN. "Simulations and experimental assessment of dosimetric evaluations for breast imaging studies with Synchrotron Radiation". Doctoral thesis, Università degli Studi di Trieste, 2016. http://hdl.handle.net/11368/2908074.
Pełny tekst źródłaStreszczenie:
Nel migliorare la diagnosi precoce del tumore al seno, a partire dal 2006, è attivo a Trieste uno studio clinico che utilizza la luce di sincrotrone come sorgente di raggi x per eseguire l’esame mammografico (Castelli and et al., 2011).
Il sincrotrone Elettra (situato sull’altopiano carsico di Basovizza, Trieste) ospita infatti una facility per l’esecuzione dell’esame mammografico lungo la linea di luce SYRMEP (SYnchrotron Radiation for MEdical Physics).
A partire dal 2013 è attivo il progetto SYRMA-CT (finanziato dall’Istituto Nazionale di Fisica Nucleare) che ha come principale obbiettivo quello di attuare il primo studio clinico di Breast Computed Tomography con luce di sincrotone.
Il progetto SYRMA-CT (SYnchrotron Radiation for MAmmograpy - Computed Tomography) si inserisce nel trend globale di passaggio dalle immagini 2D a quelle 3D e ingloba al suo interno l’esperienza maturata durante la sperimentazione clinica del programma di Mammografia con la Radiazione di Sincrotrone (MSR).
Scopo del presente lavoro di dottorato è quello di estendere la grandezza utilizzata per il calcolo della dose in breast-CT (i.e. Mean Glandular Dose, MGD) alla particolare situazione dell’esame con luce di Sincrotrone.
L’esame prevede infatti una situazione di irraggiamento parziale dell’organo (da 3 cm fino ad un massimo di 5 cm) e l’utilizzo di una sorgente monocromatica.
Nel corso del lavoro di tesi è stato sviluppato un codice di simulazione Monte Carlo basato sul toolkit GEANT4 che permettesse di calcolare i coefficienti necessari per la stima della dose (DgNct ).
Il codice è stato validato confrontandolo sia con la letteratura che con specifiche misure sperimentali alla linea di luce SYRMEP.
Due grandezze (che estendono il concetto di MGD) per la stima della dose sono state proposte (Mettivier et al., 2016): MGDt (che tiene conto della dose dovuta alla radiaizone diffusa all’esterno della zona irragiata) e MGDv (che considera solo la dose nella regione irraggiata dell’organo).
Il codice sviluppato è inoltre utilizzato per l’ottimizzazione dei parametri energetici che saranno alla base del protocollo d’esame da sottoporre al comitato etico.
Sono in fase di studio le distribuzioni di dose che tengono conto delle diverse modalità di ir- raggiamento (quali spiral-CT, irraggiamento di tipi step and go, etc.) nonchè la possibilità di stimare le dosi post-exam attraverso l’ implementazione all’interno del codice delle immagini delle pazienti stesse ottenute durante l’esame.
26
Böhm, Jochen. "In situ tensile testing at the limits of X-ray diffraction a new synchrotron-based technique". Stuttgart Max-Planck-Inst. für Metallforschung, 2004. http://deposit.d-nb.de/cgi-bin/dokserv?idn=972182810.
Pełny tekst źródła
27
Schönau, Kristin A. [Verfasser]. "In situ Synchrotron Diffraction of Lead-Zirconate-Titanate at its Morphotropic Phase Boundary / Kristin A Schönau". Aachen : Shaker, 2008. http://d-nb.info/1162789948/34.
Pełny tekst źródła
28
Gregori, G. P. "In-situ synchrotron based investigations of the structure of iron substituted microporous catalysts under operating conditions". Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1559778/.
Pełny tekst źródłaStreszczenie:
Microporous aluminosilicates and aluminophosphates have been studied for a variety of applications. Incorporation of a transition metal ion into their framework structure allows them to be modified into functional redox catalysts for a wide range of industrially important processes. In particular, FeZSM-5 has shown remarkable catalytic activity under mild conditions for the oxidation of benzene to phenol (OBP) using N2O as oxidant. Recent work has shown that the aluminophosphate FeAlPO-5 is also equally active as a catalyst for this reaction. Therefore, the aim of this work is to investigate the changes occurring during the calcination (activation) and catalytic reaction conditions of various Fe-substituted nanoporous catalysts using synchrotron based X-ray diffraction and spectroscopic methods. High-resolution powder diffraction (HRPD) measurements were carried out on FeAlPO-5 and FeZSM-5 to investigate changes to the crystal structure occurring during calcination. Pawley refinement, indicates strong negative thermal expansion upon loss of template for FeAlPO-5. The local structure and oxidation state changes of Fe located in FeAlPO-5 and FeSAPO-34 were studied using XAS during calcination in air. In addition to the above, ruthenium containing system is also investigated to examine the possible synergistic effects between Ru and Fe by supporting over Fe containing nanoporous materials. FeMFI, FeSAPO-5, RuFeMFI and RuFeSAPO-5 were then studied using in situ Fe and Ru K-edge EXAFS during calcination in air, activation in He, and pulsed experiments with N2O/benzene. The results show reduction of Fe and Ru upon the introduction of benzene to the system, indicating that the catalytic mechanism for the (OBP) reaction may require this step for the generation of the active Fe species. In summary, the project allowed us to examine the host crystalline material and catalytically active sites using synchrotron based Xray techniques, and complementary characterisation methods.
29
Barbosa, José. "Études ex situ et in situ par rayonnement synchrotron du processus électrochimique de co-intercalation de cations métalliques (Cd2+, Ni2+, Co2+, Zn2+) dans les phases de Chevrel". Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0180/document.
Pełny tekst źródłaStreszczenie:
Les chalcogénures à clusters de Molybdène sont des structures minérales reconnues pour développer des propriétés d’accueil de cations. En effet, la remarquable mobilité des cations dans les matrices minérales construites sur les unités Mo6X8 (avec X= S, Se) des phases de Chevrel définit des systèmes redox réversibles Mo6X8 + xMn+ + xn e- <-> MxMo6X8. A côté de leurs potentialités physiques et chimiques connues, deux applications de ces réactions d’intercalation ont vu jour récemment au sein de nos équipes, en lien avec les préoccupations environnementales et de valorisation matière. Il s’agit du développement de jonction électrochimique de transfert pour la récupération sélective de cations et la mise au point de capteurs, applications validées parfaitement sur des solutions synthétiques mono-cationiques. Or pour leur développement et pour se rapprocher des cas réels, il s’avère indispensable de réaliser des études dans des solutions pluri-cationiques. Ainsi l’objectif de notre travail de thèse a été d’étudier les mécanismes d’intercalation de 4 cations métalliques (Ni2+, Cd2+, Zn2+, Co2+), représentatifs de différents effluents industriels. Une première partie s’est attachée à développer la connaissance du positionnement des processus d’intercalation mixtes de cations, contenus dans des mélanges équimolaires 0,1 M bi et tri cationiques, en mode ex situ afin d’étudier les réponses électrochimiques caractéristiques à chaque électrolyte. Cette connaissance confrontée à des contrôles structuraux et stœchiométriques permet de mieux interpréter et d’identifier les systèmes préférentiels d’insertion ainsi que le mode d’intercalation. Une seconde partie a été réalisée in situ sur grands instruments à l’ESRF afin de suivre la formation des phases au cours de l’intercalation électrochimique. Grâce à ce suivi, nous avons pu déterminer la nature des phases en présence, leur proportion (dans le cas d’un mélange), leur structure ainsi que la position exacte du cation dans la structure, notamment pour l’ion cadmium dans les phases soufrée et séléniée qui a fait l’objet d’un traitement expérimental approfondi. L’originalité de ce travail repose d’une part sur l’étude d’intercalation dans des électrolytes inédits bi et tri cationiques, d’autre part sur la détermination de structures des phases de Chevrel pas encore référencées dans la littérature (Cd2Mo6Se8). Ces résultats constituent un ensemble de données particulièrement utiles pour l’optimisation des performances des capteurs ou celle des protocoles de transferts sélectifsMolybdenum cluster chalcogenides are mineral structures known for their cation-receiving properties. Indeed, the remarkable cations mobility in the mineral matrices built on the Mo6X8 units (with X = S, Se) of the Chevrel phases defines reversible redox systems Mo6X8 + xMn+ + xn e- <-> MxMo6X8. Regarding their physical and chemical potential, two applications using the intercalation reactions have been recently developed in our teams, in connection with environmental concerns and material recovery. More precisely the development of an electrochemical transfer junction for the selective recovery of cations and the development of sensors, which were perfectly validated on synthetic mono-cationic solutions. But for their development and to get closer to real cases, it is essential to carry out studies in multi-cationic solutions. Thus the objective of our thesis work was to study the mechanisms of intercalation of 4 metal cations (Ni2+, Cd2+, Zn2+, Co2+), representative of different industrial effluents. A first part focused on developing the knowledge of the positioning of the mixed cation intercalation processes, contained in equimolar 0.1 M bi and tri cationic mixtures, in ex situ mode in order to study the electrochemical responses characteristic of each electrolyte. This knowledge, confronted with structural and stoichiometric controls, makes it possible to better interpret and identify the preferred insertion systems as well as the intercalation mode. A second part was performed in situ on great facilities at the ESRF in order to follow phase formation during electrochemical intercalation. Thanks to this monitoring, we were able to determine the phases nature involved, their proportion (in the case of a mixture), their structure as well as the exact position of the cation in the structure, in particular for the cadmium ion in the phases sulfur and selenium which has been the subject of a thorough experimental treatment. The originality of this work rests on the one hand on the intercalation study in new electrolytes bi and tri cationic, on the other hand on the determination of structures of Chevrel phases not yet referenced in the literature (Cd2Mo6Se8). These results constitute a set of data particularly useful for the optimization of sensor performance or selective transfer protocols
30
BROMBAL, LUCA. "X-ray Phase-Contrast Tomography: Underlying Physics and Developments for Breast Imaging". Doctoral thesis, Università degli Studi di Trieste, 2020. http://hdl.handle.net/11368/2960312.
Pełny tekst źródłaStreszczenie:
X-ray phase-contrast tomography is a powerful tool to dramatically increase the visibility of features exhibiting a faint attenuation contrast within bulk samples, as is generally the case of light (low-Z) materials. For this reason, the application to clinical tasks aiming at imaging soft tissues, as e.g., breast imaging, has always been a driving force in the development of this field. In this context, the SYRMA-3D project, which constitutes the framework of the present work, aims to develop and implement the first breast computed tomography system relying on the propagation-based phase-contrast technique at the Elettra synchrotron facility (Trieste, Italy). This thesis finds itself in the ‘last mile’ towards the in-vivo implementation, and the obtained results add some of the missing pieces in the realization of the project. The first part of the work introduces a homogeneous mathematical framework describing propagation-based phase contrast from the sample-induced X-ray refraction, to detection, processing and tomographic reconstruction. The original results reported in the following chapters include the implementation of a pre-processing procedure dedicated for a novel photon-counting CdTe detector; a study, supported by a rigorous theoretical model, on signal and noise dependence on physical parameters such as propagation distance and detector pixel size; hardware and software developments for improving signal-to-noise ratio and reducing the scan time; and, finally, a clinically-oriented study based on comparisons with clinical mammographic and histological images. The last part of the thesis attempts to widen the experimental horizon: first, a quantitative image comparison of the synchrotron-based setup and a clinically available breast-CT scanner is presented and then a practical laboratory implementation is detailed, introducing a monochromatic propagation-based micro-tomography setup making use on a high-power rotating anode source.
31
Zhang, Zhe. "Evaluation of infrared QCL, Synchrotron and bench-top sources for cell imaging in aqueous media". Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/evaluation-of-infrared-qcl-synchrotron-and-benchtop-sources-for-cell-imaging-in-aqueous-media(3d5f9172-8f4e-4367-93ac-62d8aa0a5994).html.
Pełny tekst źródłaStreszczenie:
Live cell imaging with FTIR spectroscopy offers a high throughput, non-damage and lab-free method to study the cells in vivo which has significant advantages in the field of cancer diagnosis and drug screening. However, due to the strong absorbance of water, using infrared spectroscopy in such field remains to be an underdeveloped topic. This project demonstrates a novel method to perform IR imaging of cells in solution. A novel water correction method, which avoids the using of water combination band, is proposed. A buffer reference and a cell reference spectra were introduced to fitting the contribution based on protein bands. This method was implemented on three types of IR spectrometers, namely conventional FTIR spectrometer, synchrotron-based FTIR spectrometer and quantum cascade laser (QCL) microscope. To date, most of the live cell imaging carried out with IR sources utilise synchrotron radiation. Recently, a new bench top system, QCL microscope, has been developed. It incorporates four tunable QCL laser sources covering the wavenumber range 900-1800 cm-1 which are many orders of magnitude brighter than conventional sources. The proposed water correction method is, therefore, capable of processing the data recorded by all three types of IR spectrometers. Three prostate cancer cell lines were employed to evaluate the water correction method and the performance of three spectrometers on imaging of cell in solution. The obtained spectra was analysed with multivariate analysis, PCA and PC-LDA which shows good separation between cell lines. The data was also examined with Random Forest algorithm to establish a classifier and the diagnostic capability of the water corrected spectra was proven.
32
Pereiro, Lopez Eva. "Grain boundary penetration in the AI/Ga system : a synchrotron radiation X-ray imaging investigation". Grenoble INPG, 2004. http://www.theses.fr/2004INPG0149.
Pełny tekst źródłaStreszczenie:
In a large number of metallic and ceramic systems, rapid penetration (10-3-100 mm/s) of microscopic intergranular liquid films along grain boundaries of the host material occurs and can provoke its mechanical decohesion. Because brittle fracture in any structural material involves human tragedy, a better understanding of the mechanisms behind it is of highest interest. Grain Boundary Penetration (GBP) of liquid Ga in Al grain boundaries has been investigated via Synchrotron Radiation X-ray Imaging. While for Al bicrystals the Ga layer propagation is linear and thickens in continuous manner, a discontinuous behaviour is found in polycrystals. In both cases, the kinetics is strongly influenced by stress. GBP in Al/Ga seems to be an "invasion-like" process where the intruding liquid separates the grains when penetratingPour différents systèmes métalliques et céramiques, la pénétration intergranulaire (10-3-100 mm/s) de la phase liquide le long des joints de grains du solide peut provoquer la décohésion du matériau. Comme la fracture de matériaux de structure peut impliquer la perte de vies humaines, il est de grand intérêt de comprendre les mécanismes qui mènent à la Pénétration aux Joints de Grains (PJG). La PJG du Ga liquide dans l'Al a été étudiée par Imagerie Synchrotron. Alors que pour les bicristaux la propagation du film de Ga est linéaire, le processus est discontinu pour les polycristaux. La cinétique de pénétration est fortement influencée par l'état de contraintes du matériau. La PJG pour Al/Ga semble être un processus d'invasion où le liquide séparerait les grains du solide lors de sa pénétration
33
Richard, Marie-Ingrid. "Étude in situ et ex situ par rayonnement synchrotron de la croissance d’îlots de GE sur substrats de Si (001) nominaux et pré-structurés". Grenoble 1, 2007. http://www.theses.fr/2007GRE10318.
Pełny tekst źródłaStreszczenie:
Les travaux présentés dans ce manuscrit sont consacrés à l'étude structurale (taille, déformation, défauts, composition) d'Îlots de Ge sur substrats de Si(OOI) nominaux et pré-structurés durant ou après croissance par épitaxie par jet moléculaire, en utilisant la diffraction (anomale) des rayons X en incidence rasante à l'ESRF. Les échantillons ont été caractérisés soit ex situ apre��s croissance sur la ligne de lumière IDOI, soit in situ durant leur croissance par EJM grâce au dispositif dédié sur la ligne BM32. Les effets dynamiques associés à l'utilisation de l'incidence rasante ont été étudiés sur la base de simulations des champs de déformations dans les nanostructures de Ge. Une nouvelle technique de rayons X a été développée pour détecter leur présence et étudier la structure de leur cœur en se concentrant sur l'intensité diffusée par les défauts autour de réflexions interdites. La forme, la taille, le mode de croissance, la composition et la présence éventuelle de défauts et/ou d'ordre atomique à l'intérieur des nanostructures ont été caractérisés en fonction du dépôt, de sa température, de la vitesse de croissance et du recuit, pour comprendre les dynamiques de croissance. L'évolution des déformations, la transition élastique-plastique, l'interdiffusion et leur relation avec les différentes morphologies des îlots ont été étudiés grâce à l'utilisation de techniques in situ de rayons X. Enfin, les croissances sur surfaces Si(OOI) nominales et pré-structurées ont été comparées, montrant qu'en modulant la surface, il est possible de changer l'état de relaxation et l'énergie élastique totale des îlots sans modifier leur composition moyenne en GeThe work presented in this manuscript focuses on the structural (size, strain, defects, composition) investigation of Ge nano-islands grown on both nominal and pre-pattemed Si(OOI) substrates by Molecular Bearn, using grazing incidence (anomalous) X-ray diffraction and scattering at ESRF. The samples were either prepared in independent MBE chambers and then characterized ex situ on the IDOI ESRF beamline, or they were characterized in situ during their MBE growth, using the BM32 ESRF beamline setup. The dynamical scattering effects occurring in grazing incidence have been studied on the basis offinite element simulations of the strain fields in nano-islands. A novel X-ray method has been developed to detect the presence of defects and to study the structure oftheir core by concentrating on measurements along rods of scattering by defects passing through bulk forbidden reflections. To obtain new insight into the dynamics of growth phenomena, the shape, size, growth mode, composition and possible defects and/or atomic ordering inside aIl islands were characterized, as a function of deposition, deposition temperature, flux and possible annealing. The evolution ofstrain, the transition from elastic to plastic relaxation, the intermixing and the correlation ofthese internaI parameters with the different morphologies of the island have been addressed using in situ scattering methods. At last, the growth on nominal and patterned Si(OO 1) surfaces were compared, showing that by tuning the surface curvature, it is possible to change the relaxation state and the overaIl elastic energy of islands without modifying their mean Ge composition
34
Ozkan, Cigdem. "The Controlled Drift Detector As An X-ray Imaging Device For Diffraction Enhanced Imaging". Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610414/index.pdf.
Pełny tekst źródłaStreszczenie:
Diffraction Enhanced Imaging (DEI) is an X-ray imaging technique providing specific information about the molecular structure of a tissue by means of coherently scattered photons.
A Controlled Drift Detector (CDD) is a novel 2D silicon imager developed to be used in X-ray imaging techniques.
In this work a final (complete and detailed) analysis of DEI data taken with the CDD in the ELETTRA synchrotron light source facility in Trieste (Italy) in 2005, is presented and the applicability of both this new technique and the novel detector are discussed.
35
Gallard, Manon. "Etude in situ de la cristallisation et des contraintes dans des nanostructures de GeTe par diffraction du rayonnement X synchrotron". Electronic Thesis or Diss., Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0037.
Pełny tekst źródłaStreszczenie:
Les matériaux à changement de phase (PCM, Phase Change Materials) sont utilisés dans les dispositifs mémoires PCRAM (Phase-Change Random Access Memory), dans lesquels l’information est stockée par l’état du PCM (cristallin ou amorphe, correspondant aux deux états d’information 0/1). La lecture se fait par la mesure de la résistance du PCM qui est très différente suivant son état amorphe ou cristallin. L’optimisation et la fiabilité de ces dispositifs mémoires repose sur une compréhension fine des mécanismes physiques à l’œuvre lors de la transition amorphe-cristal. Pendant cette thèse, un système modèle (GeTe) a été caractérisé in situ au synchrotron. Le comportement thermoélastique et le mécanisme de cristallisation ont été étudiés pour plusieurs géométries d’échantillon : des films minces (épaisseurs de 100 nm à 5 nm), des nano-piliers (diamètre 50 nm à 250 nm, 50 nm de haut) et des agrégats (diamètre 10 nm)Phase Change Materials (PCM) are used in PCRAM (Phase-Change Random Access Memory) devices, where the information is stored by the PCM state (crystalline or amorphous, corresponding to the two binary information states, 0/1). The stored data is read as the resistivity of the PCM which differs strongly whether it is in amorphous or crystalline state. A detailed understanding of the physical mechanisms during the amorphous to crystal phase transition is of utmost importance for the optimization and the reliability improvement of these memory devices. In this work, a model system (GeTe) was in situ characterized at a synchrotron facility. The thermoelastic behaviour and crystallization mechanism were studied for several sample geometries: thin films (thicknesses of 100 nm down to 5 nm), nano-pillars (diameter 50 nm to 250 nm, 50 nm height) and clusters (diameter of 10 nm)
36
Rauscher, Brian Craig. "In-situ optical imaging of carrier transport in multilayer solar cells". Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://handle.dtic.mil/100.2/ADA483453.
Pełny tekst źródłaStreszczenie:
Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2008.Thesis Advisor(s): Haegel, Nancy M. "June 2008." Description based on title screen as viewed on August 26, 2008. Includes bibliographical references (p. 41-42). Also available in print.
37
Krantz, Eric Paul. "An evaluation of optical holography applied to imaging in situ plankton". Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU115600.
Pełny tekst źródłaStreszczenie:
This work investigates the application of optical holography as a non-destructive means to obtain accurate visual images and three-dimensional co-ordinates of in situ plankton. In-line and off-axis modes are examined theoretically within the framework of recording the subject in water and reconstructing the image in air. The focus of this work is on the design, construction and evaluation of an off-axis recording geometry that is suitably applied to variable concentrations of plankton in the 10-5 m to 10-3 m size range. Building upon previous work in underwater hologrammetry, a novel recording geometry and the limiting conditions for high resolution image play are introduced. Crucial to this approach is the reduction of field angle and aperture of the reconstructed hologram. Most of the parallax information commonly associated with a display hologram is sacrificed in favour of preserving two-dimensional image fidelity. The image volume is considered as a narrow field angle water core that can be localised at the hologram aperture within the bounds of paraxial approximation. The depth range of the recording volume is increased by the introduction of a side-lit array of subject beams that extend a considerable distance from the hologram. Image data is interrogated in two-dimensional optical sections using a computer controlled replay system and the three dimensional co-ordinates are obtained from a standardised origin. A procedure is introduced for determining the reconstructed image point co-ordinates in air for an axial subject point recorded through a water/glass/air planar boundary of arbitrary dimensions. Experimental data is obtained for the system resolution and analysed in terms of expected theoretical values following the Raleigh criterion and the aberration and speckle limiting factors of coherent imaging. Holograms recorded of variably dense plankton populations are compared to attenuation coefficient and traditional microscope counts in order to quantify system performance.
38
Trail, Nicholas. "Imaging Profilometry For In Situ Measurement of Plasma Spray Coating Thickness". Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/560844.
Pełny tekst źródłaStreszczenie:
Thermal Barrier Coatings (TBCs), and plasma spray coatings in general, require critical control over the deposited thickness to achieve reliable coating performance. Currently, the plasma spray industry quantifies thickness by sampling the part before and after TBC deposition. Approximate thickness is thus inferred from previous runs. However, process variability can allow errors to propagate in this result that leads to wasted time and resources, and can ultimately lead to non-reliant coatings. To this end, an in situ optical fringe profilometer is developed that enables coating thickness measurements across a 2-dimensional surface. The initial profilometer concept is explored through requirements and trade studies, leading to a hardware and algorithm design family and prototype build to capture and compare real-world data to simulation and model predictions. This initial result shows a viable path-forward and the ability to achieve micrometer-scale depth resolution. Modifications and alterations to the in situ profilometer are then explored to improve the performance limits achievable. In specific, industrial spray coatings operate by dropping fine-grain media into a high pressure gas line aimed through a plasma torch to impart enough thermal and kinetic energy to stick to the part surface. This presents a challenging operational environment for an optical depth measurement sensor, working with a variable high-temperature blackbody stray light source; constant part rotation and plasma gun movement; and a non-isolated vibration environment. As such, the concept of the profilometer is further adapted specific to this end-purpose, by developing and reviewing both dual-fringe projection and plenoptic imaging. These techniques allow an improvement to both the system micro- and macroscopic depth retrieval limits, allowing a method to solve for an extended range of phase ambiguities and relax object focus requirements (respectively). The end result is a system concept and algorithm design that presents a feasible manner for automated in situ geometry and depth measurements in the plasma spray industry. The in situ fringe profilometer work described herein allows a flexible path to recover object depth information remotely, and is especially relevant for asymmetric and complex non-planar geometries, which are experiencing renewed interest with additive manufacturing processes and generally quite common to the thermal spray industry.
39
Hipp, Alexander [Verfasser], i Andreas [Akademischer Betreuer] Schreyer. "High-resolution grating-based phase-contrast imaging for synchrotron radiation sources / Alexander Hipp ; Betreuer: Andreas Schreyer". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1175584584/34.
Pełny tekst źródła
40
Henneberg, Oliver. "In-situ Untersuchungen zur Entstehung von Oberflächengittern in Polymeren". Phd thesis, Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2005/111/.
Pełny tekst źródłaStreszczenie:
In festen azobenzenhaltigen Polymeren wurde bei Bestrahlung mit blauem Licht ein makroskopischer Materialtransport beobachtet. Um die Dynamik der Gitterentstehung zu verfolgen, wurde am Speicherring für Synchrotronstrahlung ein Gitterschreibaufbau errichtet. Damit konnte erstmals in dieser Arbeit die Gitterbildungsgeschwindigkeit in-situ simultan mit Röntgen- und Lichtstreuung untersucht werden. Mit Hilfe einer speziellen Anpassung der Röntgenstreutheorie konnten sehr gute Übereinstimmungen von theoretischen Berechnungen mit den Messergebnissen erzielt werden. Dabei konnte nachgewiesen werden, dass sich zeitgleich mit einem Oberflächengitter auch ein Dichtegitter entwickelt. Durch die Trennung beider Streuanteile ließ sich die Dynamik der Strukturentstehungen bestimmen. Des weiteren konnte erstmals mit Hilfe der Photoelektronenspektroskopie die molekulare Orientierung an der Oberfläche eines Oberflächengitters nachgewiesen werden. Die Bewegungsursache kann auf einen Impulsübertrag während der Isomerisierung zurückgeführt werden, während die Bewegungsrichtung durch den elektrischen Feldvektor festgelegt wird. Die Theorie der Gitterentstehung konnte verbessert werden.Solid azobenzene containing polymers show a macroscopic material transport under illumination with blue light. A writing setup was constructed at a synchrotron beamline in order to investigate the dynamics of the grating formation. With this setup it was possible to record the grating velocity for the first time simultaneously with x-ray and laser light scattering.
A very good consistency could be achieved between the experiments and a suitable accomodation of the x-ray scattering theory. The theory reveals, that a density grating develops simultaneously with a surface grating. By separation of both parts the dynamics was determined for the density and the surface grating.
The molecular ordering was determined at the surface with photoelectron spectroscopy. A momentum transfer could be identified as the source of the movement while the electric field defines the direction of the movement. The theory of the grating formation was improved.
41
Zhang, Fengguo. "Determination of the stress field in polycrystalline materials by Laue microdiffraction". Thesis, Paris, ENSAM, 2015. http://www.theses.fr/2015ENAM0020/document.
Pełny tekst źródłaStreszczenie:
La microdiffraction Laue permet l'estimation des déformations élastiques à l'échelle du micron. La procédure d'analyse standard, bien établie, utilisée pour extraire les déformations élastiques des images de Laue est limitée par deux sources d'erreurs : la détermination de la positions des taches de Laue sur le détecteur, et la sensibilité aux paramètres de calibration du montage. Pour améliorer la procédure, nous avons développé une procédure appelée Laue-DIC qui utilise la très bonne résolution de la technique de corrélation d'images numériques (DIC). Cette méthode utilise, pour la détermination de l'incrément de déformation élastique et de rotation, le déplacement des pics entre deux configurations mécaniques, estimé par DIC, au lieu de leur position. Nous montrons que cette méthode donne un profil de contrainte en meilleur accord avec les solutions analytiques et numériques, pour des échantillons monocristallins déformés en flexion 4-points. Nous proposons également une méthode Laue-DIC améliorée, dans laquelle les paramètres de calibration sont estimés à chaque point de mesure, simultanément à la déformation élastique.En parallèle à la formulation de la méthode Laue-DIC (améliorée), nos efforts ont porté sur l'estimation de l'incertitude obtenue sur les déformations élastiques. Nous avons développé un modèle de bruit pour les images de Laue mesurées en rayonnement synchrotron, qui a été validé sur des séries de données, et qui nous a permis d'estimer les erreurs statistiques de la DIC, à partir d'images de Laue synthétiques. Ces erreurs ont ensuite été propagées dans la méthode Laue-DIC afin d'estimer les incertitudes sur les déformations élastiques, que l'on trouve en bon accord avec la fluctuation des contraintes locales estiméesLaue microdiffraction is a powerful technique to characterize the intragranular elastic strain field at the scale of micrometer. Although a standard procedure extracting elastic strain and crystal orientation from Laue image has been well-established, it can suffer from two sources of uncertainties: the determination of peaks' positions and the sensitivity to calibration parameters. In light of the high accuracy of digital image correlation (DIC), we developed the so-called Laue-DIC method which used the peaks' displacements measured by DIC instead of peaks' positions to determine the elastic strain increment and rotation between two mechanical configurations. This method has been proved more efficient than the standard procedure in terms of stress profiles of bended beam. We also developed the enhanced version of Laue-DIC. By using the term “enhanced”, we mean that we attempt to obtain both lattice matrices and calibration parameters of two configurations rather than solely the elastic strain increment and rotation from peaks' displacements.Aside from the formulation of Laue-DIC, we also developed a procedure of statistically estimating the errors of elastic strain/stress resulted from DIC errors and calibration accuracy. We have first validated a classical noise model, Poissonian-Gaussian model, from diffraction images acquired at synchrotron radiation facility. With the noise model, we could statistically estimate the DIC errors by synthesizing artificial spots. The estimated DIC errors were further transmitted into the errors of Laue-DIC through statistical tests
42
Rosciano, Fabio. "In situ synchrotron and neutron diffraction based methods for the characterization of cathodic materials for lithium-ion batteries /". Zürich : ETH/PSI, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17847.
Pełny tekst źródła
43
Cormack, Michael. "In situ synchrotron X-ray scattering studies of atomic structure and surface adsorbates at the solid-liquid interface". Thesis, University of Liverpool, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526837.
Pełny tekst źródła
44
Puncreobutr, Chedtha. "In situ synchrotron characterisation of Fe-rich intermetallic formation during the solidification of Al-Si-Cu-Fe alloys". Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/28578.
Pełny tekst źródłaStreszczenie:
The enrichment of Fe during aluminium recycling increases the quantity of Fe-rich intermetallics formed, particularly β-Al5FeSi, limiting the usage of recycled Al in many fatigue-sensitive applications. In this study, fast synchrotron x-ray tomography was used to investigate microstructure evolution and defect formation in a commercial A319 alloy (Al-7.5Si-3.5Cu, wt.%) with differing Fe-levels (0.2-0.6 wt.%Fe) during in situ solidification and isothermal uniaxial tensile deformation. The captured dynamic changes were quantified using novel image analysis techniques and analysed using computational fluid dynamics. Together these provide new insights into the mechanisms of intermetallic nucleation and growth, and their influence on flow blockage and defect formation. First, time-resolved qualitative and quantitative characterisation revealed that plate-like β-intermetallics nucleate both off the primary aluminium dendrites in the bulk of the specimen as well as off the oxide skin on the specimen surface. Second, β-intermetallic formation is largely complete before the formation of the Al-Si eutectic. Third, β-intermetallics are geometrically complex, demonstrating fast lateral growth and an ability to grow around and in between the primary dendrite arms. Last, direct impingement and potential branching are observed at a wide range of contact angles, indicating that the growth interaction might not be crystallographically related. The presence of β-intermetallics contributes to several factors that influence defect formation. They block interdendritic flow, increase pore tortuosity and reduce permeability. Pores were observed to grow preferentially along the solid surface of intermetallics, suggesting that β-intermetallics may reduce the gas-solid interfacial energy and thus facilitate the pore growth. However, they do not nucleate the porosity. The results also show that failure under mild uniaxial semi-solid tension, simulating hot-tearing, displays a much more brittle-like failure mechanism when large β-intermetallics are present, compared to the more ductile behaviour of the base alloy with unresolved β-intermetallics.
45
Shibata, Kosuke. "High-sensitivity in situ imaging of atoms in an optical lattice with narrow optical transitions". 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/185216.
Pełny tekst źródła
46
Schmutzler, Oliver [Verfasser]. "Experimental and Numerical Studies for Synchrotron-based X-ray Fluorescence Imaging in Medium Sized Objects : Experimentale und Numerische Studien zu Synchrotron gestützer Röntgenfluoreszenzbildgebung in mittelgroßen Objekten / Oliver Schmutzler". Hamburg : Staats- und Universitätsbibliothek Hamburg Carl von Ossietzky, 2020. http://d-nb.info/1225481309/34.
Pełny tekst źródła
47
Freer, Ashleigh Elizabeth. "Development of novel molecular probes and synchrotron imaging techniques to study the uptake of metallo-cylinder drugs". Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7515/.
Pełny tekst źródłaStreszczenie:
Work described in this thesis shows the design and synthesis of functionalised, triple stranded, dinuclear, supramolecular helicates. Click chemistry has been utilized to functionalise the parent ligand with dansyl and coumarin moiety’s. These ligands have been used to successfully form four novel metal complexes upon reaction with iron(II) chloride. The stability and fluorescence of these complexes has been monitored. Imidazole ligands has been functionalised by the addition of alkyne and azide side chains to allow them to undergo click reactions. This modification has not been shown to impede complex formation, as the ligand have been utilized to form novel triple stranded iron(II) and nickel(II) complexes. Synchrotron imaging has been used to produce elemental maps of cells treated with the parent metallo cylinder. This has allowed the uptake of the complex to be monitored. Two novel bromine functionalised cylinders has been developed to allow co-localisation experiments to be undertaken using XRF imaging. Cryo-SXT experiments have been undertaken to examine the morphology of HeK cells after treatment with parent metallo cylinder.
48
Zabler, Simon Andreas. "X-ray imaging by partially coherent synchrotron light application to metallic alloys, tooth dentin, and natural rock". Saarbrücken VDM Verlag Dr. Müller, 2007. http://d-nb.info/989329860/04.
Pełny tekst źródła
49
Long, Renhai. "In-situ Scanning Electron Microscopy for Electron-beam Lithography and In-situ One Dimensional Nano Materials Characterization". ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/966.
Pełny tekst źródłaStreszczenie:
In this thesis, we demonstrate in-situ scanning electron microscopy techniques for both electron beam lithography (EBL) and in-situ one dimensional nano materials electrical characterization. A precise voltage contrast image positioning for in-situ EBL to integrate nanowires into suspended structures for nanoswitch fabrication has been developed. The in-situ EBL eliminates the stage movement error and field stitching error by preventing any movements of the stage during the nanolithography process; hence, a high precision laser stage and alignment marks on the substrate are not needed, which simplifies the traditional EBL process. The ZnO piezoelectronics is also studied using nano-manipulators in scanning electron microscope. Methods to improve the contact have been demonstrated and the contacts between probe tips and the nanowires are found to have significant impact on the measurement results.
50
Villain, Pascale. "Analyse des constantes d'élasticité dans des films minces et multicouches par déformation in situ couplée à la diffraction des rayons X". Poitiers, 2002. http://www.theses.fr/2002POIT2274.
Pełny tekst źródłaStreszczenie:
Des études théoriques et expérimentales montrent que les matériaux métalliques nanostucturés peuvent présenter un comportement en élasticité différent de celui du massif. Nous avons mis au point une méthode de mesure du module d'Young et du coefficient de Poisson intragranulaires des films et multicouches supportés en couplant diffraction des rayons X et déformation in situ. Nous avons déterminé le coefficient de Poisson de Mo dans un système Ni/Mo, puis montré une inversion des coefficients de Poisson des familles {331} et {420} dans des films d'or. Combinant plusieurs techniques, nous avons constaté un adoucissement du module d'un film d'acier inoxydable. Nous avons observé un adoucissement sensible du module d'un film de tungstène, puis mesuré le module d'un film d'or, ainsi que son coefficient de Poisson qui s'avère inférieur à celui du massif. Enfin, l'étude de multicouches W/Cu de périodes 3 à 24 nm a révélé une corrélation étroite entre constantes d'élasticité et évolution microstructurale des couches WTheoretical and experimental studies have evidenced that nanostrutured materials may present an elastic behaviour different from the bulk one. We have developed a method to measure the intragranular Young's modulus and Poisson's ratio in supported thin films and multilayers by coupling X-ray diffraction and in situ tensile testing. We determined the Poisson's ratio of Mo in a Ni/Mo multilayer; then we evidenced an inversion between the Poisson's ratios of the {331} and {420} family planes in gold films. Combining several techniques, we observed a softening of the modulus in a stainless steel film. Then we evidenced a softening of the modulus in a tungsten film; we obtained the modulus of a gold film and its Poisson's ratio, which is clearly smaller than the bulk one. Finally, a study of W/Cu multilayers with periods ranging from 3 to 24 nm revealed a narrow correlation between elastic constants and microstructural evolution in the W sublayers