Rozprawy doktorskie na temat „Particle interaction”
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Stamm, Matthew T. "Particle Dynamics and Particle-Cell Interaction in Microfluidic Systems". Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/308886.
Pełny tekst źródłaStoica, Cristina. "Particle systems with quasihomogeneous interaction". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ52774.pdf.
Pełny tekst źródłaLindemann, Dirk, Kristin Stirnnagel, Daniel Lüftenegger, Annett Stange, Anka Swiersy, Erik Müllers, Juliane Reh i in. "Analysis of Prototype Foamy Virus particle-host cell interaction with autofluorescent retroviral particles". BMC, 2010. https://tud.qucosa.de/id/qucosa%3A28868.
Pełny tekst źródłaLindemann, Dirk, Kristin Stirnnagel, Daniel Lüftenegger, Annett Stange, Anka Swiersy, Erik Müllers, Juliane Reh i in. "Analysis of Prototype Foamy Virus particle-host cell interaction with autofluorescent retroviral particles". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-176566.
Pełny tekst źródłaAdera, Gashaw Bekele. "Strange particle production via the weak interaction". Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2777.
Pełny tekst źródłaIn this thesis a general relativistic formalism for neutrino-induced weak production of strange particles is presented. In our formalism it is shown that the differential cross section is constructed as a contraction between a leptonic tensor and a hadronic tensor. The electroweak theory of Glashow, Salam and Weinberg is used to calculate the leptonic tensor exactly. The hadronic current is determined from the newly derived general form of the weak hadronic current which is expressed in terms of eighteen invariant amplitudes that parametrize the hadron vertex. The Born diagram is used to approximate the unknown hadronic vertex and the numerical calculation is made by evaluating the tree diagrams in terms of standard weak form factors and the strong coupling constants in the framework of the Cabibbo theory and SU(3) symmetry. The investigation is made for charged current reactions in terms of the angular distribution of the differential cross section with respect to the outgoing kaon angle and the results are discussed.
Paleo, Cageao Paloma. "Fluid-particle interaction in geophysical flows : debris flow". Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/27808/.
Pełny tekst źródłaTehranchi, Shiela. "Particule « enfin » en français parlé et ses fonctions en discours et l'interaction". Thesis, Lyon 2, 2011. http://www.theses.fr/2011LYO20059.
Pełny tekst źródłaIn linguistic interaction, the use of the particle enfin provide various discursive activities of the speakers. In this study, we aim at determining the frequency and the occurrence varieties of this short word in the interaction, according to situations and types of activity in which the subjects commit themselves, in order to understand its interactionnal and functional characteristics. Following this purpose, we decide to adopt a multidimensional analysis framework (Conversation Analysis , Discourse in Interactions ). Our work method relies on the analysis of the participants verbal activities. It is based on audio/ video recordings. Therefore, we take notice of the recurring elements surrounding the particle, we collect these elements to convert them into the formats: seven usages of enfin have been identified, each of them subdivided in several subcategories and which can sometimes have a contradictory range (conclusive/ introductory, discontinuity/continuity, etc). In an inter-discursive approach, enfin betrays a dissimilarity in its use due to the context. As a conclusion, we can say that enfin operates differently depending to the framework nature (formal / informal)
Alton, Andrew K. "Evidence for the existence of jets in photon-parton interaction events at center of mass energies from 18 to 28 GEV". Virtual Press, 1995. http://liblink.bsu.edu/uhtbin/catkey/1014850.
Pełny tekst źródłaDepartment of Physics and Astronomy
Pan, Kai Ph D. Massachusetts Institute of Technology. "Simulating fluid-solid interaction using smoothed particle hydrodynamics method". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/109642.
Pełny tekst źródłaCataloged from PDF version of thesis.
Includes bibliographical references (pages 97-102).
The fluid-solid interaction (FSI) is a challenging process for numerical models since it requires accounting for the interactions of deformable materials that are governed by different equations of state. It calls for the modeling of large deformation, geometrical discontinuity, material failure, including crack propagation, and the computation of flow induced loads on evolving fluid-solid interfaces. Using particle methods with no prescribed geometric linkages allows high deformations to be dealt with easily in cases where grid-based methods would introduce difficulties. Smoothed Particle Hydrodynamics (SPH) method is one of the oldest mesh-free methods, and it has gained popularity over the last decades to simulate initially fluids and more recently solids. This dissertation is focused on developing a general numerical modeling framework based on SPH to model the coupled problem, with application to wave impact on floating offshore structures, and the hydraulic fracturing of rocks induced by fluid pressure. An accurate estimate of forces exerted by waves on offshore structures is vital to assess potential risks to structural integrity. The dissertation first explores a weakly compressible SPH method to simulate the wave impact on rigid-body floating structures. Model predictions are validated against two sets of experimental data, namely the dam-break fluid impact on a fixed structure, and the wave induced motion of a floating cube. Following validation, this framework is applied to simulation of the mipact of large waves on an offshore structure. A new numerical technique is proposed for generating multi-modal and multi-directional sea waves with SPH. The waves are generated by moving the side boundaries of the fluid domain according to the sum of Fourier modes, each with its own direction, amplitude and wave frequency. By carefully selecting the amplitudes and the frequencies, the ensemble of wave modes can be chosen to satisfy a real sea wave spectrum. The method is used to simulate an extreme wave event, with generally good agreement between the simulated waves and the recorded real-life data. The second application is the modeling of hydro-fracture initiation and propagation in rocks. A new general SPH numerical coupling method is developed to model the interaction between fluids and solids, which includes non-linear deformation and dynamic fracture initiation and propagation. A Grady-Kipp damage model is employed to model the tensile failure of the solid and a Drucker-Prager plasticity model is used to predict material shear failures. These models are coupled together so that both shear and tensile failures can be simulated within the same scheme. Fluid and solid are treated as a single system for the entire domain, and are computed using the same stress representation within a uniform SPH framework. Two new stress coupling approaches are proposed to maintain the stress continuity at the fluid-solid interface, namely, a continuum approach and stress-boundary-condition approach. A corrected form of the density continuity equation is implemented to handle the density discontinuity of the two phases at the interface. The method is validated against analytic solutions for a hydrostatic problem and for a pressurized borehole in the presence of in-situ stresses. The simulation of hydro-fracture initiation and propagation in the presence of in-situ stresses is also presented. Good results demonstrate that SPH has the potential to accurately simulate the hydraulic-fracturing phenomenon in rocks.
by Kai Pan.
Ph. D.
Xu, Zhenghe. "A study of hydrophobic interaction in fine particle coagulation". Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39945.
Pełny tekst źródłaRodier, Elisabeth. "Le passage et la rétention de particules colloidales dans un milieu poreux". Vandoeuvre-les-Nancy, INPL, 1993. http://docnum.univ-lorraine.fr/public/INPL_T_1993_RODIER_E.pdf.
Pełny tekst źródłaOduwole, Olayinka. "Particle interactions in a magnetophoretic system". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:f01cbb33-4dd4-4057-8891-7097e6493bce.
Pełny tekst źródłaGoy, Jérôme. "Mesures des observables tensorielles dans la réaction H(p,d)pion pour des énergies comprises entre 580 et 1300 MeV et stabilité des systèmes borroméens". Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10019.
Pełny tekst źródłaLyberatos, Andreas. "Monte Carlo simulations of interaction effects in fine particle ferromagnets". Thesis, Imperial College London, 1986. http://hdl.handle.net/10044/1/38088.
Pełny tekst źródłaJaved, Ali. "Investigation on meshfree particle methods for fluid structure interaction problems". Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/386297/.
Pełny tekst źródłaDieste, Martina. "Random-vortex-particle methods applied to broadband fan interaction noise". Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/192591/.
Pełny tekst źródłaDenz, Markus [Verfasser]. "Convergence results for stochastic particle systems with social interaction / Markus Denz". Mainz : Universitätsbibliothek Mainz, 2014. http://d-nb.info/1046966782/34.
Pełny tekst źródłaKeisling, John Davis 1969. "Approach to equilibrium for Markovian infinite particle systems with exclusion interaction". Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/282248.
Pełny tekst źródłaBethke, Nastja. "Vortex ring interaction with a particle layer : implications for sediment transport". Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611495.
Pełny tekst źródłaQin, Tong. "Numerical Simulations of Interactions of Solid Particles and Deformable Gas Bubbles in Viscous Liquids". Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/19225.
Pełny tekst źródłabubbles in viscous liquids is very important in many applications,
especially in mining and chemical industries. These interactions
involve liquid-solid-air multiphase flows and an
arbitrary-Lagrangian-Eulerican (ALE) approach is used for the direct
numerical simulations. In the system of rigid particles and
deformable gas bubbles suspended in viscous liquids, the
Navier-Stokes equations coupled with the equations of motion of the
particles and deformable bubbles are solved in a finite-element
framework. A moving, unstructured, triangular mesh tracks the
deformation of the bubble and free surface with adaptive refinement.
In this dissertation, we study four problems. In the first three
problems the flow is assumed to be axisymmetric and two dimensional
(2D) in the fourth problem.
Firstly, we study the interaction between a rising deformable bubble
and a solid wall in highly viscous liquids. The mechanism of the
bubble deformation as it interacts with the wall is described in
terms of two nondimensional groups, namely the Morton number (Mo)
and Bond number (Bo). The film drainage process is also
considered. It is found that three modes of bubble-rigid wall
interaction exist as Bo changes at a moderate Mo.
The first mode prevails at small Bo where the bubble deformation
is small. For this mode, the bubble is
hard to break up and will bounce back and eventually attach
to the rigid wall. In the second mode, the bubble may break up after
it collides with the rigid wall, which is determined by the film
drainage. In the third mode, which prevails at high Bo, the bubble
breaks up due to the bottom surface catches up the top surface
during the interaction.
Secondly, we simulate the interaction between a rigid particle and a
free surface. In order to isolate the effects of viscous drag and
particle inertia, the gravitational force is neglected and the
particle gains its impact velocity by an external accelerating
force. The process of a rigid particle impacting a free surface and
then rebounding is simulated. Simplified theoretical models are
provided to illustrate the relationship between the particle
velocity and the time variation of film thickness between the
particle and free surface. Two film thicknesses are defined. The
first is the thickness achieved when the particle reaches its
highest position. The second is the thickness when the particle
falls to its lowest position. The smaller of these two thicknesses
is termed the minimum film thickness and its variation with the
impact velocity has been determined. We find that the interactions
between the free surface and rigid particle can be divided into
three regimes according to the trend of the first film thickness.
The three regimes are viscous regime, inertial regime and jetting
regime. In viscous regime, the first film thickness decreases as the
impact velocity increases. Then it rises slightly in the inertial
regime because the effect of liquid inertia becomes larger as the
impact velocity increases. Finally, the film thickness decreases
again due to Plateau-Rayleigh instability in the jetting regime.
We also find that the minimum film thickness corresponds to an
impact velocity on the demarcation point between the viscous and
inertial regimes. This fact is caused by the balance of viscous
drag, surface deformation and liquid inertia.
Thirdly, we consider the interaction between a rigid particle and a
deformable bubble. Two typical cases are simulated: (1) Collision of
a rigid particle with a gas bubble in water in the absence of
gravity, and (2) Collision of a buoyancy-driven rising bubble with a
falling particle in highly viscous liquids. We also compare our
simulation results with available experimental data. Good agreement
is obtained for the force on the particle and the shape of the
bubble.
Finally, we investigated the collisions of groups of bubbles and
particles in two dimensions. A preliminary example of the oblique
collision between a single particle and a single bubble is conducted
by giving the particle a constant acceleration. Then, to investigate
the possibility of particles attaching to bubbles, the interactions
between a group of 22 particles and rising bubbles are studied. Due
to the fluid motion, the particles involved in central collisions
with bubbles have higher possibilities to attach to the bubble.
Ph. D.
Farnoud, Amir Mohammad. "Interaction of polymeric particles with surfactant interfaces". Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/4627.
Pełny tekst źródłaOlsson, Martin Wexö. "GPU based particle system". Thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3761.
Pełny tekst źródłaSalama, I. M. "High temperature particle -to-metal interaction in a simulated gas turbine environment". Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/4610.
Pełny tekst źródłaZhang, Hao. "Numerical investigation of particle-fluid interaction system based on discrete element method". Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/284833.
Pełny tekst źródłaEsta tesis se centra en la investigación numérica de sistemas partícula-líquido basado en la técnica Discrete Element Method (DEM). La tesis consta de tres partes, en cada una de las cuales se ha acoplado el método DEM con diferentes esquemas/solucionadores en la fase fluida. En la primera parte, hemos acoplado los métodos DEM con Direct Numerical Simulation (DNS) para estudiar casos de "particle-laden turbulent flow". Se investigó numéricamente el efecto de las colisiones en el comportamiento de las partículas en el flujo turbulento completamente desarrollado en un conducto cuadrado recto. Tres tamaños de partículas se consideraron con diámetros de 50, 100 y 500 micrometros. En primer lugar, el transporte de partículas por el flujo turbulento se estudió en la ausencia del efecto gravitacional. Entonces, la deposición de partículas se estudió bajo el efecto de la fuerza de gravedad normal a la pared, en el que se discutieron la influencia de la tasa de colisiones en re-suspensión de las partículas y la fase final de la distribución de partículas en el suelo del conducto, respectivamente. En la segunda parte, se ha acoplado los métodos DEM con Lattice Boltzmann Method (LBM) para estudiar la sedimentación de partículas en flujo laminar newtoniano. Un nuevo metodo combinado LBM-IBM-DEM se presentó y ha sido aplicado para modelar la sedimentación de dos partículas circulares bi-dimensionales en flujos Newtonianos incompresibles. Se estudiaron casos de sedimentación en una cavidad de una sola esfera, y sedimentación de dos partículas en un canal, las características de la velocidad de la partícula durante la sedimentación y cerca de la base fueron también examinados. En el último caso, un ejemplo numérico de sedimentación de 504 partículas fue finalmente presentado para demostrar la capacidad del método combinado. Además, se ha presentado un método "Particulate Immersed Boundary Method" (PIBM) para la simulación de flujos multifásicos partícula-fluido y ha sido evaluado en dos y tres dimensiones. En comparación con el método IBM convencional, se puede esperar con el mismo número de partículas y de malla un SpeedUp docenas de veces superior en la simulación bidimensional y cientos de veces en la simulación en tres dimensiones. Se llevaron a cabo simulaciones numéricas de la sedimentación de partículas en los flujos newtonianos basados en una combinación LBM - PIBM - DEM, mostrando que el PIBM podría capturar las características de los flujos de partículas en el líquido y fue en efecto un esquema prometedor para la solución de problemas de interacción fluido-partícula. En la última parte, se ha acoplado el método DEM con las ecuaciones promediadas de Navier-Stokes (NS) para estudiar el transporte de partículas y el proceso de desgaste en la pared de una tubería. Se utilizó un caso de transporte neumático para demostrar la capacidad del modelo acoplado. Entonces se simuló el proceso de bombeo de hormigón, de donde se obtuvo la presión hidráulica y la distribución de la velocidad de la fase fluida. Se monitoreó la frecuencia de impacto de las partículas en la tubería doblada, se propuso un nuevo modelo de intensidad de colisión promediado en tiempo para investigar el proceso de desgaste del codo basado en la fuerza de impacto. Se predijo la ubicación del daño máximo desgaste por erosión en el codo. Además, se examinaron las influencias de la velocidad de pulpa, la orientación y el ángulo de curvatura del codo en la ubicación del punto de punción.
Ballard, Nicholas. "Anisotropic colloids in soft matter environments : particle synthesis and interaction with interfaces". Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/54360/.
Pełny tekst źródłaEarly, Juliana Marie. "Investigation of orthogonal blade-vortex interaction using a particle image velocimetry technique". Thesis, University of Glasgow, 2006. http://theses.gla.ac.uk/619/.
Pełny tekst źródłaSchimmoller, Brian Keith. "A bubble-particle interaction model for flotation combining hydrodynamic and surface forces". Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-09192009-040332/.
Pełny tekst źródłaBigongiari, Alessandra. "High Intensity Laser-Plasma Grating Interaction : surface wave excitation and particle acceleration". Palaiseau, Ecole polytechnique, 2012. http://pastel.archives-ouvertes.fr/docs/00/75/83/55/PDF/alebigo_TESI_rapporteurs.pdf.
Pełny tekst źródłaSurface waves in solids were first observed by Wood in 1902 as an anomaly in the diffraction of a continuous light source from a metal grating: the diffracted spectrum presented dark lines corresponding to certain wavelengths, which were later explained (Fano, 1941) in terms of the excitation of a surface wave sustained by the grating. Similarly to the metal grating case, a surface plasma wave (SPW) can be resonantly excited by a laser pulse at the surface of a laser-produced over-dense plasma, if the correct matching conditions are provided. SPWs propagate along the plasma-vacuum interface and are characterized by a localized, high frequency, resonant electric field. In the present work we describe numerically the dynamics of the plasma and the field distribution associated to SPW excitation, using two-dimensional particle-in-cell (PIC) simulations, where the plasma surface is initially pre-formed so that the SPW excitation conditions are fulfilled. We examine the surface wave excitation for a large range of laser intensities (Iλ2 =10^15-10^20 μm^2/Wcm^2) in order to study the transition from the non-relativistic to the relativistic regime. The simulations in which the wave is resonantly excited are compared to cases in which the resonant conditions are not provided and the coupling of the laser with the target is analyzed. We have considered the following aspects of the laser-plasma interaction, for different laser and target parameters: i) the laser absorption and the electric field at the surface ii) the generation of a quasi-static magnetic field iii) the electron heating and iiii) the ion acceleration. The possibility to excite a surface plasma wave on a structured target for a large range of laser energies has been demonstrated. In the cases where the surface wave is excited the electric field component normal to the target is amplified at the surface by a factor ranging from 3. 2 to 7. 2 with respect to the laser field. The absorption is also increased,for example it raises from 27% when the SPW is not excited up to 73% for Iλ^2=10^9 μm^2/Wcm^2. We have defined the optimal conditions for efficient coupling which increase laser absorption, that correspond to the relativistic laser intensities (Iλ^2>10^19 μm^2/Wcm^2). In this regime the main absorption mechanism is vacuum heating, associated to particles oscillating in the field perpendicular to the target, which is enhanced by the stronger, localized field of the SPW. The generation of a quasi-static magnetic field has been studied analytically and compared to the result of PIC simulations. The different field structure in presence of a SPW and for a flat target suggests that the enhanced field strength has caused partial confinement of particles at the target surface when SPW is present. The effects of the surface wave are more pronounced in thin laminar targets where electrons recirculate into the target interacting several times with the wave. Efficient electron heating increases the energy of the ions which are accelerated at both the irradiated and not irradiated target surface by the hot electrons space charge field. For the thinnest target (3. 5 μm) the ion cut-off energy is about 14 Mev, approximately twice the value obtained when the SPW is not excited
Calabretta, Jacob S. "A Three Dimensional Vortex Particle-Panel Code For Modeling Propeller-Airframe Interaction". DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/336.
Pełny tekst źródłaChandramohan, Rajiv. "Measurement of particle interaction properties for the incorporation into Discrete Element Methods". Thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/5565.
Pełny tekst źródłaThe principle aim of this research project is to measure parameters which are pertinent for numerical simulations in discontinuous media. One such numerical tool, the Discrete Element Method (DEM), is a promising technique for predicting the dynamics of charge motion with in a mill. Particle interactions in DEM are calculated by contact force and force displacement laws at each particle contact. These contact events are characterized by parameters that are often fitted or estimated due to the lack of accurate experimental measurements. The aim of this project is to experimentally measure the necessary interaction properties required for the DEM analysis and to test the DEM models against the measured experimental results. An in-flight binary collisions drop tester is constructed to measure the material interaction properties of two spheres. The collision event is captured photographically and pre- and post- relative velocities are measured. The binary collisions of the particles are carefully controlled by relay timing circuits and they are captured on digitized images using a SLR digital camera. The particles are illuminated using digital strobes controlled by a signal generator. The heights of the colliding particles are adjusted to vary the drop velocities prior to collision. The measured relative velocities arc applied in rigid body theory of binary impact to extract the required material interaction properties. The parameters measured from the binary collision include coefficients of tangential and normal restitution and friction. The analysis presented here draws on the work of Maw et al and Foerster et al, which is an extension of the Hertz theory of impact to the oblique impact of the elastic bodies with circular contacts. Initial numerical simulations using the viscous damping model is performed in Particle Flow Code (PFC) and a comparison between experimental and numerical results presented.
Jones, Peter Michael. "A silicon array for conversion electron detection". Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309867.
Pełny tekst źródłaMaity, Tuhin Subhra Weeks Kevin. "Temporal order of interaction directs native assembly of the mammalian signal recognition particle". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,778.
Pełny tekst źródłaTitle from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
Klotzky, Jens [Verfasser], i Christian [Gutachter] Klingenberg. "Well-posedness of a fluid-particle interaction model / Jens Klotzky ; Gutachter: Christian Klingenberg". Würzburg : Universität Würzburg, 2018. http://d-nb.info/1170061613/34.
Pełny tekst źródłaChen, Qiang. "Development of a full particle PIC method for simulating nonlinear wave-structure interaction". Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760902.
Pełny tekst źródłaHarvey, David Richard. "Measuring the self-interaction cross-section of dark matter with astronomical particle colliders". Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10447.
Pełny tekst źródłaPayan, Oldouz. "Detailed modelling of fluid-particle interaction in sediment transport with applications in rivers". Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/10489/.
Pełny tekst źródłaDoche, Antoine. "Particle acceleration with beam driven wakefield". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX023/document.
Pełny tekst źródłaPlasma wakefield accelerators (PWFA) or laser wakefield accelerators (LWFA) are new technologies of particle accelerators that are particularly promising, as they can provide accelerating fields of hundreds of Gigaelectronvolts per meter while conventional facilities are limited to hundreds of Megaelectronvolts per meter. In the Plasma Wakefield Acceleration scheme (PWFA) and the Laser Wakefield Acceleration scheme (LWFA), a bunch of particles or a laser pulse propagates in a gas, creating an accelerating structure in its wake: an electron density wake associated to electromagnetic fields in the plasma. The main achievement of this thesis is the very first demonstration and experimental study in 2016 of the Plasma Wakefield Acceleration of a distinct positron bunch. In the scheme considered in the experiment, a lithium plasma was created in an oven, and a plasma density wave was excited inside it by a first bunch of positrons (the drive bunch) while the energy deposited in the plasma was extracted by a second bunch (the trailing bunch). An accelerating field of 1.36 GeV/m was reached during the experiment, for a typical accelerated charge of 40 pC. In the present manuscript is also reported the feasibility of several regimes of acceleration, which opens promising prospects for plasma wakefield accelerator staging and future colliders. Furthermore, this thesis also reports the progresses made regarding a new scheme: the use of a LWFA-produced electron beam to drive plasma waves in a gas jet. In this second experimental study, an electron beam created by laser-plasma interaction is refocused by particle bunch-plasma interaction in a second gas jet. A study of the physical phenomena associated to this hybrid LWFA-PWFA platform is reported. Last, the hybrid LWFA-PWFA scheme is also promising in order to enhance the X-ray emission by the LWFA electron beam produced in the first stage of the platform. In the last chapter of this thesis is reported the first experimental realization of this last scheme, and its promising results are discussed
Hosein, Falahaty. "Enhanced fully-Lagrangian particle methods for non-linear interaction between incompressible fluid and structure". Kyoto University, 2018. http://hdl.handle.net/2433/235070.
Pełny tekst źródłaArai, Nozomi. "Self-Assembly of Colloidal Particles with Controlled Interaction Forces". Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263693.
Pełny tekst źródłaSun, Guangyuan. "Stochastic Simulation of Lagrangian Particle Transport in Turbulent Flows". BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5838.
Pełny tekst źródłaCross, Andrew John. "The electron-phonon interaction in GaAs/(AlGa)As quantum wells". Thesis, University of Nottingham, 2001. http://eprints.nottingham.ac.uk/14316/.
Pełny tekst źródłaCrowe, Adam. "Inclined Negatively Buoyant Jets and Boundary Interaction". Thesis, University of Canterbury. Civil and Natural Resources Engineering, 2013. http://hdl.handle.net/10092/7895.
Pełny tekst źródłaSharp, David Keith. "Trends in single-particle energies in N=51 nuclei". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/trends-in-singleparticle-energies-in-n51-nuclei(fe5f71e3-c0ab-4ace-98ae-af674f923b44).html.
Pełny tekst źródłaMartinez, Bertrand. "Effets radiatifs et quantiques dans l'interaction laser-matière ultra-relativiste". Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0442/document.
Pełny tekst źródłaForthcoming multi-petawatt laser systems, such as the French Apollon and European Extreme Light Infrastructure facilities, are expected to deliver on-target laser intensities exceeding 10^22 W/cm^2. A novel regime of laser-matter interaction will ensue, where ultra-relativistic plasma effects are coupled with copious generation of high-energy photons and electron-positron pairs. This will pave the way for many transdisciplinary applications in fundamental and applied research, including the development of unprecedentedly intense, compact particle and radiation sources, the experimental investigation of relativistic astrophysical scenarios and tests of quantum electrodynamics theory.In recent years, most theoretical studies performed in this research field have focused on the impact of synchrotron photon emission and Breit-Wheeler pair generation, both directly induced by the laser field and believed to be dominant at intensities >10^22 W/cm^2. At the lower intensities (≲10^21 Wcm^(-2)) currently attainable, by contrast, photon and pair production mainly originate from, respectively, Bremsstrahlung and Bethe-Heitler/Trident processes, all triggered by atomic Coulomb fields. The conditions for a transition between these two regimes have, as yet, hardly been investigated, particularly by means of integrated kinetic numerical simulations. The purpose of this PhD is precisely to study the aforementioned processes under various physical scenarios involving extreme laser-plasma interactions. This work is carried out using the particle-in-cell CALDER code developed at CEA/DAM which, over the past few years, had been enriched with modules describing the synchrotron and Breit-Wheeler processes.Our first study aimed at extending the simulation capabilities of CALDER to the whole range of photon and positron generation mechanisms arising during relativistic laser-plasma interactions. To this purpose, we have implemented modules for the Coulomb-field-mediated Bremsstrahlung, Bethe-Heitler and Trident processes. Refined Bremsstrahlung and Bethe-Heitler cross sections have been obtained which account for electronic shielding effects in arbitrarily ionized plasmas. Following validation tests of the Monte Carlo numerical method, we have examined the competition between Bremsstrahlung/Bethe-Heitler and Trident pair generations by relativistic electrons propagating through micrometer copper foils. Our self-consistent simulations qualitatively agree with a 0-D theoretical model, yet they show that the deceleration of the fast electrons due to target expansion significantly impacts pair production.We then address the competition between Bremsstrahlung and synchrotron emission from copper foils irradiated at 10^22 Wcm^(-2). We show that the maximum radiation yield (into >10 keV photons) is achieved through synchrotron emission in relativistically transparent targets of a few 10 nm thick. The efficiency of Bremsstrahlung increases with the target thickness, and takes over synchrotron for >2μm thicknesses. The spectral properties of the two radiation processes are analyzed in detail and correlated with the ultrafast target dynamics.Finally, we investigate the potential of nanowire-array targets to enhance the synchrotron yield of a 10^22 Wcm^(-2) femtosecond laser pulse. Several radiation mechanisms are identified depending on the target parameters and as a function of time. A simulation scan allows us to identify the optimal target geometry in terms of nanowire width and interspacing, yielding a ∼10% radiation efficiency. In this configuration, the laser-driven nanowire array rapidly expands to form a quasi-uniform, relativistically transparent plasma. Furthermore, we demonstrate that uniform sub-solid targets can achieve synchrotron yields as high as in nanowire arrays, but that the latter enable a strong emission level to be sustained over a broader range of average plasma density
Vera, Gomis Pablo de. "Charged particle interaction with biological materials: modelling and application to ion beam cancer therapy". Doctoral thesis, Universidad de Alicante, 2016. http://hdl.handle.net/10045/56995.
Pełny tekst źródłaJin, Hanbing. "Particle-in-Cell Simulation of Electromagnetic Pulse Generated by High-power Laser-target Interaction". Thesis, KTH, Fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231339.
Pełny tekst źródłaBouzid, Djallel. "Study of high impact polypropylene morphology : interaction between the polymerisation process and particle morphology". Lyon 1, 2004. http://www.theses.fr/2004LYO10185.
Pełny tekst źródłaThe principal objective of this thesis is to elucidate how the rubber phase produced in the copolymerisation step is distributed inside growing particles of high impact polypropylene, and how the amount of rubber incorporated in the original polypropylene matrix influences the overall morphology and mechanical properties of the final product. To this end, polymer was made under different conditions, and the products were characterised and analysed in order to attempt to understand how the morphology of the isotactic polypropylene matrix changes during particle growth, how rubber flows in the porous network, and how the EPR arrives at, and pools on the surface of the particle. All of these phenomena are obviously dependent on each other, which complicates the problem. A representation which incorporates the rheological properties of the copolymer combined with the structure of the homopolymer polypropylene matrix is probably a more realistic approach to take
Slapak, Rikard. "O⁺ heating in the high altitude cusp and mantle due to wave-particle interaction". Licentiate thesis, Luleå tekniska universitet, Rymdteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26562.
Pełny tekst źródłaGodkänd; 2011; 20111007 (riksla); LICENTIATSEMINARIUM Ämnesområde: Rymdteknik/Space Engineering Examinator: Docent Hans Nilsson, IRF Kiruna Diskutant: Doktor Stephan Buchert, IRF Uppsala Tid: Fredag den 11 november 2011 kl 10.00 Plats: IRF, Kiruna
Pachler, Klaus, Thomas Frank i Klaus Bernert. "Simulation of Unsteady Gas-Particle Flows including Two-way and Four-way Coupling on a MIMD Computer Architectur". Universitätsbibliothek Chemnitz, 2002. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200200352.
Pełny tekst źródłaIdouakass, Malik. "Linear and nonlinear study of the precessional fishbone instability". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4756/document.
Pełny tekst źródłaThe wave-particle interaction in plasmas is an important research subject, for fundamental physical understanding as well as for the operation of fusion devices such as tokamaks. This interaction can cause the existence of unstable modes, such as the fishbone instability that is observed in tokamak plasmas. It results from the resonant interaction between an electro-magnetic wave living in the plasma and a population of supra-thermal particles. This mode causes the ejection of a portion of these energetic particles, and is thus detrimental to the confinment of energy in a tokamak, and it is characterized by a frequency down-chirping, i.e. a decrease of frequency of the mode during its evolution. In this thesis, a model for the fishbone instability is developed, that describes the thermal plasma with fluid equations and the supra-thermal particles with the kinetic Vlasov equation. This model is highly simplified in order to understand the basic mechanisms leading to destabilization, frequency chirping, and particle ejection. The linear theory of this model is then done, showing the conditions that lead to the existence of an instability, and that allow the characterization of its linear behavior. The linear analytic results are then compared to numerical linear results obtained with a code, based on the assumptions of the model, that was developed during this PhD and the results are found to be in good agreement. Finally, the code is used to explore the nonlinear behavior of energetic particles in the later phase of the fishbone instability. The main mechanism responsible for the frequency chirping and energetic particle ejection is identified and studied in detail