Готові списки джерел за темами / Electric properties tomography

Добірка наукової літератури з теми "Electric properties tomography"

Автор: Grafiati

Опубліковано: 14 березня 2023

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Статті в журналах з теми "Electric properties tomography"

Hampe, Nils, Max Herrmann, Thomas Amthor, Christian Findeklee, Mariya Doneva, and Ulrich Katscher. "Dictionary-based electric properties tomography." Magnetic Resonance in Medicine 81, no. 1 (September 23, 2018): 342–49. http://dx.doi.org/10.1002/mrm.27401.

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Arduino, Alessandro. "EPTlib: An Open-Source Extensible Collection of Electric Properties Tomography Techniques." Applied Sciences 11, no. 7 (April 4, 2021): 3237. http://dx.doi.org/10.3390/app11073237.

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Electric properties tomography (EPT) is a novel magnetic resonance imaging–based method to estimate non-invasively the distribution of the electric properties in the human body. In this paper, EPTlib, an open-source extensible C++ library collecting ready-to-use algorithms for electric properties tomography, is presented. Currently, EPTlib implements three techniques, named Helmholtz-EPT, convection-reaction-EPT and gradient-EPT, whose derivation and implementation is deeply discussed. Moreover, the configuration files needed by the terminal application included in EPTlib to apply the implemented techniques are outlined. The three techniques are applied to a couple of model problems in order to highlight their main features and the effects of the tunable parameters.

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Katscher, Ulrich, Dong-Hyun Kim, and Jin Keun Seo. "Recent Progress and Future Challenges in MR Electric Properties Tomography." Computational and Mathematical Methods in Medicine 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/546562.

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MR Electric Properties Tomography (EPT) is a lately developed medical imaging modality capable of visualizing both conductivity and permittivity of the patient at the Larmor frequency usingB1maps. The paper discusses the development of EPT reconstructions, EPT sequences, EPT experiments, and challenging issues of EPT.

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Rahimov, Anar, Amélie Litman, and Guillaume Ferrand. "MRI-based electric properties tomography with a quasi-Newton approach." Inverse Problems 33, no. 10 (September 20, 2017): 105004. http://dx.doi.org/10.1088/1361-6420/aa7ef2.

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Jensen, Bjørn Christian Skov, and Kim Knudsen. "Sound speed uncertainty in acousto-electric tomography." Inverse Problems 37, no. 12 (November 26, 2021): 125011. http://dx.doi.org/10.1088/1361-6420/ac37f8.

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Abstract The goal in acousto-electric tomography is to reconstruct an image of the unknown electric conductivity inside an object from boundary measurements of electrostatic currents and voltages collected while the object is penetrated by propagating ultrasound waves. This problem is a coupled-physics inverse problem. Accurate knowledge of the propagating ultrasound wave is usually assumed and required, but in practice tracking the propagating wave is hard due to inexact knowledge of the interior acoustic properties of the object. In this work, we model uncertainty in the sound speed of the acoustic wave, and formulate a suitable reconstruction method for the interior power density and conductivity. We also establish theoretical error bounds, and show that the suggested approach can be understood as a regularization strategy for the inverse problem. Finally, we numerically simulate the sound speed variations from a numerical breast tissue model, and computationally explore the effect of using an inaccurate sound speed on the error in reconstructions. Our results show that with reasonable uncertainty in the sound speed reliable reconstruction is still possible.

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Arduino, A., O. Bottauscio, M. Chiampi, and L. Zilberti. "MRI safety application of the magnetic resonance-based electric properties tomography." Physica Medica 92 (December 2021): S132. http://dx.doi.org/10.1016/s1120-1797(22)00281-2.

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Azzouz, Mustapha, Martin Hanke, Chantal Oesterlein, and Karl Schilcher. "The Factorization Method for Electrical Impedance Tomography Data from a New Planar Device." International Journal of Biomedical Imaging 2007 (2007): 1–7. http://dx.doi.org/10.1155/2007/83016.

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We present numerical results for two reconstruction methods for a new planar electrical impedance tomography device. This prototype allows noninvasive medical imaging techniques if only one side of a patient is accessible for electric measurements. The two reconstruction methods have different properties: one is a linearization-type method that allows quantitative reconstructions; the other one, that is, the factorization method, is a qualitative one, and is designed to detect anomalies within the body.

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Katscher, Ulrich, and Cornelius A. T. van den Berg. "Electric properties tomography: Biochemical, physical and technical background, evaluation and clinical applications." NMR in Biomedicine 30, no. 8 (May 24, 2017): e3729. http://dx.doi.org/10.1002/nbm.3729.

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Arduino, Alessandro, Mario Chiampi, Francesca Pennecchi, Luca Zilberti, and Oriano Bottauscio. "Monte Carlo Method for Uncertainty Propagation in Magnetic Resonance-Based Electric Properties Tomography." IEEE Transactions on Magnetics 53, no. 11 (November 2017): 1–4. http://dx.doi.org/10.1109/tmag.2017.2713984.

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Balidemaj, Edmond, Cornelis A. T. van den Berg, Astrid L. H. M. W. van Lier, Aart J. Nederveen, Lukas J. A. Stalpers, Hans Crezee, and Rob F. Remis. "B1-based SAR reconstruction using contrast source inversion–electric properties tomography (CSI-EPT)." Medical & Biological Engineering & Computing 55, no. 2 (April 23, 2016): 225–33. http://dx.doi.org/10.1007/s11517-016-1497-6.

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Дисертації з теми "Electric properties tomography"

DeGeorge, Vincent G. "Chemical Partitioning and Resultant Effects on Structure and Electrical Properties in Co-Containing Magnetic Amorphous Nanocomposites for Electric Motors." Research Showcase @ CMU, 2017. http://repository.cmu.edu/dissertations/885.

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chemical partitioning of Cobalt-containing soft magnetic amorphous and nanocomposite materials has been investigated with particular focus on its consequences on these materials’ nanostructure and electrical resistivity. Theory, models, experiment, and discussion in this regard are presented on this class of materials generally, and are detailed in particular on alloys of composition, (Fe65Co35)79.5+xB13Si2Nb4-xCu1.5, for X={0- 4at%}, and Co-based, Co76+YFe4Mn4-YB14Si2Nb4, for Y={0-4at%}. The context of this work is within the ongoing efforts to integrate soft magnetic metal amorphous and nanocomposite materials into electric motor applications by leveraging material properties with motor topology in order to increase the electrical efficiency and decrease the size, the usage of rare-earth permanent magnets, and the power losses of electric motors. A mass balance model derived from consideration of the partitioning of glass forming elements relates local composition to crystal state in these alloys. The ‘polymorphic burst’ onset mechanism and a Time-Temperature- Transformation diagram for secondary crystallization are also presented in relation to the partitioning of glass forming elements. Further, the intrinsic electrical resistivity of the material is related to the formation of virtual bound states due to dilute amounts of the glass forming elements. And lastly, a multiphase resistivity model for the effective composite resistivity that accounts for the amorphous, crystalline, and glass former-rich amorphous regions, each with distinct intrinsic resistivity, is also presented. The presented models are validated experimentally on the Co-containing alloys by Atom Probe Tomography performed through collaboration with Pacific Northwestern National Laboratory.

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Henry-Poulter, Siobhan. "An investigation of transport properties in natural soils using electrical resistance tomography." Thesis, Lancaster University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389933.

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Weigand, Maximilian [Verfasser]. "Monitoring structural and physiological properties of crop roots using spectral electrical impedance tomography / Maximilian Weigand." Bonn : Universitäts- und Landesbibliothek Bonn, 2017. http://d-nb.info/1139048988/34.

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Slater, Lee David. "An investigation of the ability of cross-borehole electrical imaging to assist in the characterisation of hydrogeological properties at the field scale." Thesis, Lancaster University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360648.

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Cadiou, François. "Étude de l'impact de la microstructure sur les propriétés effectives électriques des batteries lithium-ion." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI108.

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Cette étude porte sur la compréhension du lien existant entre l’architecture microstructurelle et les propriétés effectives de conductivité dans les électrodes des batteries Li-ion. Les batteries Li-ion sont très intéressantes pour des domaines tels que le transport électrique. En effet, elles présentent une grande densité d’énergie et de puissance ce qui en fait de bons substituts pour les moteurs thermiques. Cependant, même si elles sont maintenant assez largement utilisées dans beaucoup de domaines, il y a toujours besoin d’en optimiser les performances. Ceci passe par une meilleure compréhension de l’impact de la microstructure sur les propriétés effectives pour réduire l’écart entre théorie et pratique. L’attention est portée ici sur les électrodes positives des batteries lithium-ion. Les caractéristiques tridimensionnelles telles que la percolation des phases, leur tortuosité ou encore leurs dimensions caractéristiques ont un fort impact sur les propriétés à l'échelle macroscopique. Leur étude nécessite l’utilisation de techniques d’imagerie 3D comme la tomographie aux rayons X et la tomographie sériée par faisceau d’ions focalisés et MEB (FIB/SEM) pour obtenir des données quantitatives et en interpréter les propriétés de transport de charge. Ces volumes sont alors traités (segmentation et analyses morphologiques) et utilisés comme base pour des simulations numériques. La méthode FFT (Fast Fourrier Transform) avec opérateur de Green « discret » est choisie. Ces simulations permettent, soit de remonter aux propriétés de conduction électrique des phases, à partir de la mesure de la conductivité de l’électrode, par méthode inverse, soit de prédire la conductivité effective de l’électrode, en utilisant des propriétés mesurées expérimentalement sur les phases prises séparément. Les microstructures 3D numériques peuvent également être altérées afin de prédire l’impact, sur ses propriétés effectives, de changements de composition dans la formulation de l’électrode. De nouveaux outils consacrés à la meilleure compréhension de la relation entre microstructure, propriétés effectives et performance des batteries lithium-ion sont développés
Li-ion batteries are interesting for applications such as electric vehicles. They have indeed a high energy and power density, which makes them good substitutes for internal combustion engines. However, even if they are now quite widely used in many fields, there is still a need to optimize their performance. This requires a better understanding of the impact of the electrodes microstructure on their effective properties to narrow the gap between ideal and practical performance. Three-dimensional characteristics such as the carbon additive percolation or the tortuosity of the porosity have a strong impact on the electrode charge transport properties and power performance. The use of 3D imaging techniques such as X-ray tomography and serial focused ion beam and SEM tomography (FIB/SEM) is very powerful to quantify the electrode microstructures and interpret their charge transport properties. Furthermore, by processing the reconstructed volumes, one can use them as a basis for numerical simulations. We have chosen the FFT (Fast Fourrier Transform) method with "discrete" Green operator for numerical computations. These simulations can either be used to back calculate the phase (active material or conducting additive/binder) conduction properties from macroscopic electrical measurements by inverse method, or to predict the electrode effective conductivity from the phase conductivities. The 3D numerical microstructures obtained can also be modified in order to predict the influence of compositional changes in the electrode formulation on its properties. This study sets new tools to understand better the relationships between microstructure, effective electrical properties and the performance of Li-ion battery composite electrodes

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Hwang, Junyeon Kaufman M. J. "Characterization and mechanical properties of nanoscale precipitates in modified Al-Si-Cu alloys using transmission electron microscopy and 3D atom probe tomography." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3661.

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Hwang, Junyeon. "Characterization and Mechanical Properties of Nanoscale Precipitates in Modified Al-Si-Cu Alloys Using Transmission Electron Microscopy and 3D Atom Probe Tomography." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3661/.

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Among the commercial aluminum alloys, aluminum 319 (Al-7wt%Si-4wt%Cu) type alloys are popularly used in automobile engine parts. These alloys have good casting characteristics and excellent mechanical properties resulting from a suitable heat treatment. To get a high strength in the 319 type alloys, grain refining, reducing the porosity, solid solution hardening, and precipitation hardening are preferred. All experimental variables such as solidification condition, composition, and heat treatment are influence on the precipitation behavior; however, precipitation hardening is the most significant because excess alloying elements from supersaturated solid solution form fine particles which act as obstacles to dislocation movement. The challenges of the 319 type alloys arise due to small size of precipitate and complex aging response caused by multi components. It is important to determine the chemical composition, crystal structure, and orientation relationship as well as precipitate morphology in order to understand the precipitation behavior and strengthening mechanism. In this study, the mechanical properties and microstructure were investigated using transmission electron microscopy and three dimensional atom probe tomography. The Mn and Mg effects on the microstructure and mechanical properties are discussed with crystallographic study on the iron intermetallic phases. The microstructural evolution and nucleation study on the precipitates in the low-Si 319 type aluminum alloys are also presented with sample preparation and analysis condition of TEM and 3DAP tomography.

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Tammas-Williams, Samuel. "XCT analysis of the defect distribution and its effect on the static and dynamic mechanical properties in Ti-6Al-4V components manufactured by electron beam additive manufacture." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/xct-analysis-of-the-defect-distribution-and-its-effect-on-the-static-and-dynamic-mechanical-properties-in-ti6al4v-components-manufactured-by-electron-beam-additive-manufacture(cb034391-b61f-4e16-91cd-7ad3c9ec6312).html.

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Selective electron beam melting (SEBM) is a promising powder bed Additive Manufacturing technique for near-net-shape manufacture of high-value titanium components. An extensive research program has been carried out to characterise in 3D the size, volume fraction, and spatial distribution of the pores in model samples, using X-ray computed tomography (XCT), and correlate them to the SEBM process variables. The average volume fraction of the pores (97.5 %) where fatigue cracks would initiate based on the relative stress intensity factor of all the pores. In contrast, crack growth was found to be insensitive to porosity, which was attributed to the much higher stress concentration generated by the crack in comparison to the pores. Some crack diversion was associated with the local microstructure, with prior β grain boundaries often coincident with crack diversion.

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Chelaghma, Saber Ayoub. "Fonctionnalisation de composites C/PEKK pour application aérospatiale : caractérisation, modélisation et influence sur les propriétés du composite." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30362.

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La réduction du poids des avions est l'un des grands défis de l'industrie aérospatiale. Afin d'atteindre les objectifs ambitieux en matière de consommation de carburant et de réduction des émissions, des composites renforcés de fibres de carbone, ont été introduits sur le marché. Ces matériaux suscitent un intérêt croissant, néanmoins, ils possèdent une faible conductivité électrique, ne permettant pas de garantir une protection contre la foudre. Pour cette raison, les composites chargés de particules conductrices font l'objet d'activités de recherche en cours. L'objectif est le développement de composites multifonctionnels avec des propriétés électriques accrues. Pour l'heure, la matrice thermoplastique de référence est le PEEK mais ce polymère reste toutefois cher, et sa température d'élaboration élevée. Dans ce but, des matrices thermoplastiques, telles que le PEKK, sont à nouveau étudiées. Entre la matière première et la pièce finale, la matrice thermoplastique subit plusieurs cycles de traitement à haute température (imprégnation, consolidation, procédés d'assemblage) au cours desquelles sa capacité à cristalliser évolue sans cesse. Afin d'évaluer l'impact du procédé et des constituants du composite sur les propriétés du composite, la cristallisation a fait l'objet d'une attention particulière. Deux dispositifs expérimentaux complémentaires ont été utilisés afin de caractériser la cristallisation : une platine chauffante, permettant d'appliquer un cycle thermique et d'observer la cristallisation en microscopie optique ainsi que la calorimétrie différentielle à balayage. L'influence des fibres de carbone et des particules conductrices sur la cinétique de cristallisation a été évaluée. Une diminution des temps de cristallisation a été observée à travers l'augmentation du taux de germination. Les données recueillies ont servi à développer un modèle de cinétique de cristallisation identifié à travers une approche originale en se basant sur des données microscopiques et enthalpiques. Ce modèle permet de prédire les cinétiques de cristallisation des composites à matrice PEKK mais il ne permet pas de rendre compte de la microstructure finale engendrée. Or, cette dernière a un impact non négligeable sur les propriétés mécaniques comme cela a été prouvé à travers des essais de nano-indentation. Pour prévoir la microstructure finale, un modèle basé sur l'approche pixel coloring a été développé. L'influence des fibres de carbone a été introduite à travers la formation d'une phase transcristalline. Une bonne corrélation est constatée entre l'approche analytique, la simulation et les données expérimentales en termes de cinétique de cristallisation. Des caractérisations mécaniques et électriques ont été effectuées afin d'évaluer les performances de ces nouveaux matériaux. Sur les matériaux étudiés, la réponse mécanique n'est pas homogène comme observé sur des essais de traction suivis en stéréo-corrélation. L'étude de la santé matière montre l'existence de défauts, en particulier, à l'échelle de la microstructure. Afin de prendre en compte ces particularités, il est ainsi nécessaire de décrire plus finement la microstructure. Pour cela, la tomographie à rayons X a été utilisée afin de caractériser le composite. Les récents développements de cette technique permettent, en combinaison avec des outils de segmentation, de reconstruire une géométrie représentative du matériau. Cette géométrie est utilisée pour simuler le comportement mécanique ainsi que la cristallisation. Les simulations numériques d'un VER sont capables de prédire les propriétés d'un pli, puis celles du stratifié. Cette modélisation multi-échelle pourrait réduire le nombre et le coût des campagnes expérimentales. Ainsi, déterminer les propriétés de la structure finale en se basant sur des caractérisations et simulations à l'échelle de la microstructure est un enjeu scientifique et industriel stratégique. Ce travail constitue une contribution vers cette approche
Reducing aircraft weight is one of the major challenges facing the aerospace industry. In order to achieve the ambitious goals of fuel consumption and emission reduction, carbon-fiber reinforced composites have been introduced to the market. These materials are attracting increasing interest, however, they have low electrical conductivity to ensure protection against lightning strike. For this reason, composites filled with conductive particles are the subject of ongoing research activities. The objective is the development of multifunctional composites with enhanced electrical properties. Actually, the most used thermoplastic matrix is PEEK, but this polymer remains expensive, and its processing temperature is high. For this purpose, thermoplastic matrices, such as PEKK, are again studied. Between the raw material and the final part, the thermoplastic matrix undergoes several thermal steps with high temperature exposure (impregnation, consolidation, forming and assembly processes) during which its ability to crystallize evolves continuously. In order to evaluate the impact of the process and the composite constituents on its properties, crystallization has been the subject of particular attention. Two complementary experimental devices were used to characterize the crystallization. The heating stage, allows to apply a thermal cycle and observe the crystallization in optical microscopy and differential scanning calorimetry. The influence of carbon fibers and conductive fillers on the crystallization kinetics was evaluated. A decrease in crystallization times was observed through the increase of the nucleation rate. The collected data were used to develop a kinetic model identified through an original approach based on microscopic data. This model makes it possible to predict the crystallization kinetics of PEKK composites. Nevertheless, it does not make it possible to predict the final microstructure. However, the microstructure has a significant impact on mechanical properties as it has been proven through nano-indentation tests. To predict the final microstructure, a model based on the pixel coloring approach has been developed. The influence of carbon fibers has been introduced through the formation of a transcrystalline phase. A good correlation is found between the analytical approach, the simulation and the experimental data in terms of crystallization kinetics. Mechanical and electrical characterizations were performed to evaluate the performance of these new materials. On the studied materials, the mechanical response is not homogeneous as observed on tensile tests followed in stereo-correlation. The study of matter health shows the existence of defects, in particular, at the microstructure level. In order to take this particularity into account, it is thus necessary to describe the microstructure more finely. For this, X-ray tomography was used to characterize the composite. Recent developments in this technique allow, in combination with segmentation tools, to reconstruct a representative geometry of the material. This geometry is used to simulate the mechanical behaviour as well as the crystallization. The numerical simulations of an RVE are able to calculate the properties of a ply, then those of a laminate. This multi-scale modelling could reduce the number and cost of experimental campaigns. Thus, determining the properties of the final structure based on characterizations and simulation at the microstructure scale is a strategic scientific and industrial issue. This work is a contribution towards this approach

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Perret, Anouk. "Méthodologie de caractérisation microstructurale 3D de matériaux poreux structurés pour la thermique." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0042/document.

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Depuis 30 ans, les exigences règlementaires en matière d’isolation thermique des bâtiments augmentent sans cesse. Pour mieux isoler, et conserver la surface habitable et la valeur patrimoniale, il est nécessaire d’augmenter les performances des isolants thermiques. Si les meilleurs systèmes classiques d’isolant atteignent désormais des conductivités thermiques proches de 30 mW/(m.K), les matériaux supers isolants à pression atmosphérique affichent moins de 18 mW/(m.K) et sont à base d’aérogels de silice. Cette matière première doit ses excellentes performances thermiques, à d’une part la taille de ces nanopores inférieure à 70nm, et d’autre part leur très forte quantité. Ceci induit par contre de très faibles propriétés mécaniques, les systèmes super isolants formulés avec des aérogels sont donc toujours des composites : empilement granulaire faiblement lianté. Pour développer l’optimisation de ces formulations, il est nécessaire de disposer d’outils de caractérisation microstructurales multiéchelles dédiés aux aérogels et au suivi pas à pas des étapes d’élaboration post synthèse. Ce travail de thèse a pour objectif de les mettre en place et de les valider. Les matériaux supports de cette thèse, sont des aérogels de silice hydrophobes granulaires et deux formulations liantées en phase aqueuse. Ces formulations architecturées, par une faible fraction volumique de liant organique de taille nanométrique, se distinguent par la taille et le type de surfactant employé, et les performances tant thermiques que mécaniques obtenues. Tout d’abord, le réseau poreux de silice à l’échelle nanométrique a été imagé et caractérisé par tomographie électronique. Cette partie vise à fournir une distribution en taille de pores, particules et agrégats, destinée à alimenter des modèles thermo-mécaniques. Dans un second temps, l’empilement granulaire des aérogels non liantés a été étudié par tomographie aux rayons X. Les résultats de compacité, les morphologies des réseaux de pores, et de grains ont été couplés aux mesures de masse volumique et de porosité inter-granulaire afin de dégager un lien entre microstructure de l’empilement granulaire et conductivité thermique mesurée. Enfin, les interactions aérogels de silice/liant sont imagées en utilisant l’ESEM wet-stem. Une méthodologie quantitative permet ensuite de s’assurer que le surfactant employé induit bien d’une part une dispersion homogène des aérogels, et d’autre part un réseau texturé de liant. Pour conclure, les propriétés thermiques et mécaniques sont mesurées sur les composites référence et des composites innovants avec une étude détaillée des microstructures formées en synergie. Des pistes d’optimisation matériau par opacification intra-granulaire des aérogels sont proposées, un nouveau surfactant est infirmé. Les outils développés valident ainsi leur pertinence pour assurer la qualification des futures formulations de matériaux super isolants
The national objectives on the reduction of the rejections of greenhouse gases bring to the necessity of a thermal renovation for 75 % of the French buildings. As the requirements for old and new buildings increase their standards, design thinner and more efficient insulation materials is of great and increasing interest. New insulating materials with thermal conductivities lower than the still dry air (25 mW / (m. K)), such as based silica xerogel products (15 mW / ( m.K )), recently developed, are an interesting choice to answer those new fonctionnalities. In our study, silica xerogels (porosity > 80 %, specific surface > 600 m ²/g) are available as granular materials and binded stiff composite boards (xerogels / latex). The optimization of these materials requires to understand the link between their microstructure, their thermal conductivity and their mechanical behaviour

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Книги з теми "Electric properties tomography"

Cassidy, Jim, Donald Bissett, Roy A. J. Spence OBE, Miranda Payne, and Gareth Morris-Stiff. Principles of chemotherapy. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199689842.003.0005.

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Principles of radiation oncology outlines the physical and biological effects of ionising radiation, and its use in clinical oncology. Radiobiology, examining the response of tissue to ionising radiation, is described with regards to normal and malignant tissues. The effect of fractionation, the delivery of radiotherapy in a series of repeated exposures, is examined. The damaging effects on normal tissues are considered, particularly nonreversible late effects including carcinogenesis. Therapeutic exposure to ionising radiation is contrasted between radical and palliative radiotherapy. The physical properties of ionising radiation beams are described for superficial x-rays, megavoltage x-rays, and electrons. The process of treatment planning is summarised through beam dosimetry, target and critical organ outlining, dose planning, treatment verification, prescription and delivery. Computerised tomography is used for outlining and for verification, using cone beam CT. 0ther methods for image guided radiotherapy include fiducial markers. Increasingly intensity modulated radiotherapy is proving beneficial in reducing normal tissue damage during radical treatment. Stereotactic radiotherapy is used in the radical treatment of small unresectable malignancies. The clinical use of electron therapy, brachytherapy and intraoperative radiotherapy is described. Nuclear medicine uses unsealed radionuclides in imaging primary malignancies and their metastases, and in targeted radiotherapy. Examples include PET scanning, bone scanning, and radio iodine therapy. Whole body irradiation is used to improve outcomes after high-dose chemotherapy with stem cell or bone marrow transplantation.

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Частини книг з теми "Electric properties tomography"

Sadleir, Rosalind, and Camelia Gabriel. "Electromagnetic Properties of Tissues." In Electrical Impedance Tomography, 33–52. 2nd ed. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429399886-3.

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Katscher, Ulrich, Atul Singh Minhas, and Nitish Katoch. "Magnetic Resonance Electrical Properties Tomography (MREPT)." In Advances in Experimental Medicine and Biology, 185–202. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-03873-0_8.

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Dalmas, Florent, and Lucian Roiban. "Three-dimensional Microstructural Characterization of Polymer Nanocomposites by Electron Tomography." In Functional and Physical Properties of Polymer Nanocomposites, 7–27. Chichester, UK: John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781118542316.ch2.

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Lymperopoulos, Georgios, Panagiotis Lymperopoulos, Victoria Alikari, Chrisoula Dafogianni, Sofia Zyga, and Nikoletta Margari. "Applications for Electrical Impedance Tomography (EIT) and Electrical Properties of the Human Body." In Advances in Experimental Medicine and Biology, 109–17. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-57348-9_9.

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Díaz Rondón, Luis F., and Jan Tesarik. "Processing of Standard MR Images Prior Execution of the MR-Based Electrical Properties Tomography (MREPT) Method." In IFMBE Proceedings, 785–88. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-9023-3_142.

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"Imaging Conductivity and Permittivity of Tissues Using Electric Properties Tomography." In Quantifying Morphology and Physiology of the Human Body Using MRI, 445–78. CRC Press, 2013. http://dx.doi.org/10.1201/b14814-19.

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Zhang, Lifeng. "Image Fusion of ECT/ERT for Oil-Gas-Water Three-Phase Flow." In Global Applications of Pervasive and Ubiquitous Computing, 97–102. IGI Global, 2013. http://dx.doi.org/10.4018/978-1-4666-2645-4.ch011.

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The tomographic imaging of process parameters for oil-gas-water three-phase flow can be obtained through different sensing modalities, such as electrical resistance tomography (ERT) and electrical capacitance tomography (ECT), both of which are sensitive to specific properties of the objects to be imaged. However, it is hard to discriminate oil, gas and water phases merely from reconstructed images of ERT or ECT. In this paper, the feasibility of image fusion based on ERT and ECT reconstructed images was investigated for oil-gas-water three-phase flow. Two cases were discussed and pixel-based image fusion method was presented. Simulation results showed that the cross-sectional reconstruction images of oil-gas-water three-phase flow can be obtained using the presented methods.

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"Magnetic Resonance Electrical Impedance Tomography." In Electro-Magnetic Tissue Properties MRI, 77–190. IMPERIAL COLLEGE PRESS, 2014. http://dx.doi.org/10.1142/9781783263400_0003.

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Liu, Zhe, Zhou Chen, and Yunjie Yang. "Review of Machine Learning for Bioimpedance Tomography in Regenerative Medicine." In Advances in Medical Technologies and Clinical Practice, 271–92. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-5092-5.ch013.

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Monitoring cell growth and activities is crucial for regenerative medicine. Although optical imaging can provide high resolution, such methods are limited by the penetration depth. Bioimpedance tomography is an alternative way as it can overcome the penetration problem and possess the advantages of non-radiative, non-destructive, and high temporal resolution. In addition, with the rapid development of machine leaning, learning-based bioimpedance tomography is gradually introduced into regenerative medicine and demonstrates powerful potential. This chapter aims to provide an overview of the state-of-the-art machine learning methods of bioimpedance tomography in regenerative medicine while offering perspectives for future research directions. This chapter first summarizes the electrical properties of tissues and the principle of electrical impedance tomography (EIT) then extensively reviews the recent progress on learning-based single-modal and multi-modal imaging methods of EIT for regenerative medicine. Finally, promising future research directions are discussed.

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Kuwahara, Yoshihiko. "Microwave Imaging for Breast Cancer Detection." In Breast Cancer [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97313.

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Microwave imaging (MI) is characterized by no exposure, stronger contrast between soft tissues than X-rays and ultrasound, and a smaller device scale. This chapter describes the electrical properties of the breast tissue that underlie MI, and then outlines the MI hardware configuration and three imaging algorithms: confocal imaging, scattering tomography, and near-field holography. After that, we will introduce the actual equipment and experimental results using the three imaging algorithms. Finally, we will summarize the challenges of realizing a medical imaging device using MI.

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Тези доповідей конференцій з теми "Electric properties tomography"

Arduino, Alessandro, Oriano Bottauscio, Mario Chiampi, and Luca Zilberti. "Uncertainty propagation in phaseless electric properties tomography." In 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA). IEEE, 2019. http://dx.doi.org/10.1109/iceaa.2019.8879147.

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Arduino, A., O. Bottauscio, and L. Zilberti. "An open-source library for magnetic resonance-based electric properties tomography." In 2021 International Conference on Electromagnetics in Advanced Applications (ICEAA). IEEE, 2021. http://dx.doi.org/10.1109/iceaa52647.2021.9539842.

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Voigt, Tobias. "Imaging conductivity using electric properties tomography — Initial clinical results in glioma patients." In 2011 XXXth URSI General Assembly and Scientific Symposium. IEEE, 2011. http://dx.doi.org/10.1109/ursigass.2011.6051346.

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Arduino, A., F. Pennecchi, L. Zilberti, O. Bottauscio, and M. Chiampi. "Monte Carlo method for uncertainty propagation in magnetic resonance-based electric properties tomography." In 2017 IEEE International Magnetics Conference (INTERMAG). IEEE, 2017. http://dx.doi.org/10.1109/intmag.2017.8007964.

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Balidemaj, E., J. Trinks, C. A. T. van den Berg, A. J. Nederveen, A. L. van Lier, L. J. A. Stalpers, J. Crezee, and R. F. Remis. "CSI-EPT: A novel contrast source approach to MRI based electric properties tomography and patient-specific SAR." In 2013 International Conference on Electromagnetics in Advanced Applications (ICEAA). IEEE, 2013. http://dx.doi.org/10.1109/iceaa.2013.6632328.

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Bobzin, K., N. Bagcivan, I. Petković, J. Schein, K. Landes, G. Forster, K. Hartz-Behrend, et al. "Homogenization of Coating Properties in Atmospheric Plasma Spraying – Current Results of a DFG (German Research Foundation)-Funded Research Group." In ITSC2010, edited by B. R. Marple, A. Agarwal, M. M. Hyland, Y. C. Lau, C. J. Li, R. S. Lima, and G. Montavon. DVS Media GmbH, 2010. http://dx.doi.org/10.31399/asm.cp.itsc2010p0533.

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Abstract In the area of atmospheric plasma spraying, newly-developed triple-cathode technologies offer the potential to homogenize the coating properties with respect to porosity and residual stresses. Focused on numerical simulation, combined with advanced diagnostics, the goal of this research group is to adjust these properties systematically. A numerical model that couples fluid dynamic, electro-magnetic and thermal phenomena for a three-cathode torch was developed to investigate the plasma and the electric arc behaviour inside the torch. With help of self-developed computer tomography equipment, which is based on emission spectroscopy, combined with the solution of the Saha equation in thermodynamical equilibrium, it is now possible to reconstruct the 3- dimensional temperature distribution close to the torch outlet. This measurement allows us to confirm the torch numerical modelling. Coating formation is simulated by coupled computational fluid dynamics (CFD) and FEM simulation, so that fluid structure interaction is taken into account. This innovative approach has the advantage to predict residual stresses which occur during cooling and moreover the shrinking effects can be considered. By simulation of the individual regions, in combination with experimental results, which also include the particle velocity, diameter and surface temperature, the corresponding process parameters can be obtained for the desired coating properties.

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Satriano, Alessandro, Edward J. Vigmond, and Elena S. Di Martino. "A Feature-Based Mechano-Electric Finite Element Model of the Left Atrium With Pressure-to-Mitral-Flow Coupling." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80927.

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The modeling of complex biological systems requires many degrees of sophistication. Among them, we can enumerate heterogeneous tissue properties, a complex geometry that can be obtained only through proper imaging techniques and the interaction of the organ of interest with the surrounding structures. In the case of the left atrium, three physical domains govern its behavior: mechanical, electrical and fluidic. Different mechanical conditions, in terms of stresses and consequent strains, affect the electrical activity occurring across the tissue, and jointly, the mechanical and electrical activities regulate the correct and timely contraction of the chamber. A strongly coupled mechano-electrical model of the atrial chamber cannot be accomplished without accounting for the directional heterogeneity of the tissue, because both the electrical and the mechanical properties of the tissue are not isotropic. The fluid entering from the pulmonary veins during the filling phase of the atrium causes the pressure in the atrium to rise until the difference between the pressure in the ventricular and atrial chamber is negative (higher atrial pressure) and the mitral valve opens. After the opening of the valve, two distinct emptying phases ensue, a passive and an active one. During the passive emptying phase the pressure in the ventricle slowly rises, affecting the flow through the valve itself. During the active phase, the contraction of the atrium walls causes the pressure in the atrium to rise. Our laboratory has developed a finite element dynamic mechano-electric model of the left atrium behavior starting from multi-detector computed tomography images. We accounted for the directional heterogeneity of the tissue because both the electrical and the mechanical properties of the tissue are not isotropic. As a first step, we modeled the effect of the blood flow in the atrium (fluidic domain) by assuming a temporally varying pressure across the cardiac cycle. In spite of this assumption, i.e. of a “dry” pressure-driven model, we cannot ignore the contribution to the presence of the left ventricle downstream of the mitral valve. In fact, the ventricular pressure counteracts the volume decrease due to the passive and active emptying on the atrial chamber. Moreover, during the active phase of the atrium cycle, the atrial pressure rises in response to the resistance of the mitral flow to time changes (c wave).

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Matoorian, N. "Dental electromagnetic tomography: properties of tooth tissues." In IEE Colloquium on `Innovations in Instrumentation for Electrical Tomography'. IEE, 1995. http://dx.doi.org/10.1049/ic:19950638.

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Remis, R. F., A. Webb, S. Mandija, R. L. Leijsen, P. S. Fuchs, P. R. S. Stijnman, and C. A. T. van den Berg. "Electrical properties tomography using contrast source inversion techniques." In 2017 International Conference on Electromagnetics in Advanced Applications (ICEAA). IEEE, 2017. http://dx.doi.org/10.1109/iceaa.2017.8065434.

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Chu, Xiaolei, Hamed Heidari, Alex Abelson, Matthew Law, Caroline Qian, Gergely T. Zimanyi, Davis Unruh, Chase Hansen, and Adam J. Moule. "Structural characterization of a polycrystalline epitaxially-fused colloidal quantum dot superlattice by electron tomography." In Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XVIII, edited by Wounjhang Park, André-Jean Attias, and Balaji Panchapakesan. SPIE, 2021. http://dx.doi.org/10.1117/12.2595872.

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Звіти організацій з теми "Electric properties tomography"

Tzfira, Tzvi, Michael Elbaum, and Sharon Wolf. DNA transfer by Agrobacterium: a cooperative interaction of ssDNA, virulence proteins, and plant host factors. United States Department of Agriculture, December 2005. http://dx.doi.org/10.32747/2005.7695881.bard.

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Agrobacteriumtumefaciensmediates genetic transformation of plants. The possibility of exchanging the natural genes for other DNA has led to Agrobacterium’s emergence as the primary vector for genetic modification of plants. The similarity among eukaryotic mechanisms of nuclear import also suggests use of its active elements as media for non-viral genetic therapy in animals. These considerations motivate the present study of the process that carries DNA of bacterial origin into the host nucleus. The infective pathway of Agrobacterium involves excision of a single-stranded DNA molecule (T-strand) from the bacterial tumor-inducing plasmid. This transferred DNA (T-DNA) travels to the host cell cytoplasm along with two virulence proteins, VirD2 and VirE2, through a specific bacteriumplant channel(s). Little is known about the precise structure and composition of the resulting complex within the host cell and even less is known about the mechanism of its nuclear import and integration into the host cell genome. In the present proposal we combined the expertise of the US and Israeli labs and revealed many of the biophysical and biological properties of the genetic transformation process, thus enhancing our understanding of the processes leading to nuclear import and integration of the Agrobacterium T-DNA. Specifically, we sought to: I. Elucidate the interaction of the T-strand with its chaperones. II. Analyzing the three-dimensional structure of the T-complex and its chaperones in vitro. III. Analyze kinetics of T-complex formation and T-complex nuclear import. During the past three years we accomplished our goals and made the following major discoveries: (1) Resolved the VirE2-ssDNA three-dimensional structure. (2) Characterized VirE2-ssDNA assembly and aggregation, along with regulation by VirE1. (3) Studied VirE2-ssDNA nuclear import by electron tomography. (4) Showed that T-DNA integrates via double-stranded (ds) intermediates. (5) Identified that Arabidopsis Ku80 interacts with dsT-DNA intermediates and is essential for T-DNA integration. (6) Found a role of targeted proteolysis in T-DNA uncoating. Our research provide significant physical, molecular, and structural insights into the Tcomplex structure and composition, the effect of host receptors on its nuclear import, the mechanism of T-DNA nuclear import, proteolysis and integration in host cells. Understanding the mechanical and molecular basis for T-DNA nuclear import and integration is an essential key for the development of new strategies for genetic transformation of recalcitrant plant species. Thus, the knowledge gained in this study can potentially be applied to enhance the transformation process by interfering with key steps of the transformation process (i.e. nuclear import, proteolysis and integration). Finally, in addition to the study of Agrobacterium-host interaction, our research also revealed some fundamental insights into basic cellular mechanisms of nuclear import, targeted proteolysis, protein-DNA interactions and DNA repair.

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