Dissertations / Theses on the topic 'Non-equilibrium effects'
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Hader, J., I. Kilen, S. W. Koch, and J. V. Moloney. "Non-equilibrium effects in VECSELs." SPIE-INT SOC OPTICAL ENGINEERING, 2017. http://hdl.handle.net/10150/625513.
Full textBarrett-Freeman, Conrad. "Effects of advection on non-equilibrium systems." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/5846.
Full textNoto, Antonio. "Non-equilibrium Casimir interactions : from dynamical to thermal effects." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT279/document.
Full textIn this thesis, after an introduction where we briefly present the general context of Casimir physics, we present the results obtained during the PhD. At first, we show our work about the van der Waals/Casimir-Polder interactions between two atoms in an out-of-equilibrium condition due to their uniformly accelerated motion. We study the system of two uniformly accelerated atoms in vacuum space, when they are in their ground-state and when they are in a correlated state (one excited and one ground-state atom). We analyze this system both with an heuristic semiclassical model and with a more rigorous method, based on a separation of radiation reaction and vacuum fluctuations contributions, that we extend starting from a general procedure known in literature. We find a change of the distance-dependence of the interaction due to the acceleration. We show that Casimir-Polder forces between two relativistic uniformly accelerated atoms, interacting with the scalar field, exhibit a transition from the short-distance thermal-like behavior predicted by the Unruh effect to a long-distance nonthermal behavior, associated with the breakdown of a local inertial description of the system. In addition, we obtain new features of the resonance interaction in the case of atoms interacting with the quantum electromagnetic field.Next, we present our work about a new optomechanical coupling of an effectively oscillating mirror with a Rydberg atoms gas, mediated by the dynamical atom-mirror Casimir-Polder force. We find that this coupling may produce a near-field resonant atomic excitation not related to the excitation of atoms by the few real photons expected by dynamical Casimir effect. In accessible experimental conditions, this excitation probability is significant (about 20%) making the observation of this new dynamical Casimir-Polder effect possible. For this reason, we propose a realistic experimental configuration to realize this system made of a cold atom gas trapped in front of a semiconductor substrate, whose dielectric properties are periodically modulated in time.Finally, we focus on our results obtained for the Casimir-Lifshitz pressure between two different dielectric lamellar gratings. This system is assumed to be in an out-of-thermal-equilibrium configuration, i.e. the two gratings have two different temperatures and they are immersed in a thermal bath having a third temperature. The computation of the pressure is based on a method exploiting the scattering operators of the bodies, deduced using the Fourier modal method. In our numerical results we characterize in detail the behavior of the pressure, both by varying the three temperatures and by changing the geometrical parameters of the gratings. In this way we show that it is possible to tune the force from attractive to repulsive or to strongly reduce the pressure for large ranges of temperatures. Moreover, we stress that the interplay between nonequilibrium effects and geometrical periodicity make this system particularly interesting for the observation of the repulsive Casimir force
Dobrovolskas, Vidas. "Effects of convection and non-equilibrium radiation transfer in stellar atmospheres." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2013. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2013~D_20131216_081850-53537.
Full textDisertacijoje nagrinėjama konvekcijos ir nelokalios termodinaminės pusiausvyros (NLTP) įtaka įvairių cheminių elementų spektro linijų formavimuisi skirtingo metalingumo pagrindinės sekos posūkio taško (PSPT) bei raudonųjų milžinių sekos (RMS) žvaigždžių atmosferose. Konvekcijos įtaka spektro linijų formavimuisi buvo tirima analizuojant cheminių elementų gausos įverčių, gaunamų taikant 3D hidrodinaminius ir 1D hidrostatinius PSPT bei RMS žvaigždžių atmosferų modelius bei lokalios termodinaminės pusiausvyros (LTP) artinį, skirtumus. Gauti rezultatai rodo, jog konvekcijos įtaka C, O, Si, Ti, Fe, and Ni spektro linijų formavimuisi yra didžiausia mažiausio metalingumo PSPT ir RMS žvaigždžių atmosferose, o gausų skirtumai tarp 3D hidrodinaminių ir 1D hidrostatinių modelių prognozuojamų cheminių elementų gausų gali siekti atitinkamai iki –1.1 ir –0.8 dex. 3D hidrodinaminių ir NLTP reiškinių analizė Galaktikos kamuoliniams spiečiams 47 Tuc ir NGC 6752 priklausančių žvaigždžių atmosferose parodė, jog NLTP efektų įtaka deguonies ir natrio spektro linijų formavimuisi šių žvaigždžių atmosferose yra žymiai didesnė už konvekcijos įtaką. Disertacijoje taip pat gauti lengvųjų cheminių elementų (Li, O ir Na) bei bario gausų įverčiai Galaktikos kamuolinių spiečių 47 Tuc ir NGC 6752 žvaigždžių atmosferose, ištirtos cheminių elementų gausų tarpusavo sąsajos, bei aptarti galimi spiečių cheminės raidos scenarijai.
Meyer, Hugues [Verfasser], and Tanja [Akademischer Betreuer] Schilling. "Generalized Langevin equations and memory effects in non-equilibrium statistical physics." Freiburg : Universität, 2020. http://d-nb.info/1239556543/34.
Full textBlumenstein, Andreas Harald [Verfasser]. "Gold Surface Nanostructuring with Ultrashort Laser Pulses - Study of Non-equilibrium Effects / Andreas Harald Blumenstein." Kassel : Universitätsbibliothek Kassel, 2019. http://d-nb.info/1191199355/34.
Full textAmaratunga, Shane R. "A numerical study into surface catalytic effects in non-equilibrium reacting viscous laminar hypersonic flow." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266941.
Full textKayser, Jona [Verfasser], Andreas [Akademischer Betreuer] Bausch, and Matthias [Akademischer Betreuer] Rief. "Non-equilibrium Effects in Cytoskeletal Networks / Jona Kayser. Gutachter: Andreas Bausch ; Matthias Rief. Betreuer: Andreas Bausch." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1046404784/34.
Full textKayser, Jona J. S. [Verfasser], Andreas [Akademischer Betreuer] Bausch, and Matthias [Akademischer Betreuer] Rief. "Non-equilibrium Effects in Cytoskeletal Networks / Jona Kayser. Gutachter: Andreas Bausch ; Matthias Rief. Betreuer: Andreas Bausch." München : Universitätsbibliothek der TU München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:91-diss-20131210-1178714-0-0.
Full textKlewe, Christoph [Verfasser]. "Static and non-equilibrium magnetic proximity effects in Pt/NiFe2O4 and Pt/Ni1 – xFex heterostructures / Christoph Klewe." Bielefeld : Universitätsbibliothek Bielefeld, 2016. http://d-nb.info/1084887142/34.
Full textCarvalho, Vítor Manuel Costa. "Non-Keynesian Effects of Fiscal Policy in a New-Keynesian General Equilibrium Model for the Euro Area." Doctoral thesis, Faculdade de Economia da Universidade do Porto, 2008. http://hdl.handle.net/10216/20601.
Full textLi, Ting. "Experimental Study of the Effects of Nanosecond-Pulsed Non-equilibrium Plasmas on Low-Pressure, Laminar, Premixed Flames." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417632325.
Full textCarvalho, Vítor Manuel Costa. "Non-Keynesian Effects of Fiscal Policy in a New-Keynesian General Equilibrium Model for the Euro Area." Tese, Faculdade de Economia da Universidade do Porto, 2008. http://hdl.handle.net/10216/20601.
Full textWernsdorfer, Julia [Verfasser], Walter [Akademischer Betreuer] Hofstetter, and Maria-Roser [Akademischer Betreuer] Valenti. "Interacting ultracold gases in optical lattices: non-equilibrium dynamics and effects of disorder / Julia Wernsdorfer. Gutachter: Walter Hofstetter ; Maria-Roser Valenti." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2012. http://d-nb.info/1044275146/34.
Full textOzaki, Junichi. "Dynamical quantum effects in cluster dynamics of Fermi systems." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199083.
Full textMonturet, Serge. "Inelastic effects in electronic currents at the nanometer scale." Phd thesis, Université Paul Sabatier - Toulouse III, 2008. http://tel.archives-ouvertes.fr/tel-00469906.
Full textCapellmann, Ronja F. [Verfasser], Stefan U. [Akademischer Betreuer] Egelhaaf, and Jan K. G. [Gutachter] Dhont. "Non-equilibrium effects in colloidal mixtures caused by particle interactions and external potentials / Ronja F. Capellmann ; Gutachter: Jan K. G. Dhont ; Betreuer: Stefan U. Egelhaaf." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2018. http://d-nb.info/1151383171/34.
Full textChepelianskii, Alexei. "Non equilibrium transport and chirality in mesoscopic physics." Paris 11, 2010. http://www.theses.fr/2010PA112324.
Full textDuring my thesis I investigated the signatures of chiraIity in the electrical transport of mesoscopic systems. This led me to study the magnetic field symmetry of nonlinear transport. I showed that even for two terminal devices, nonlinear transport has rich magnetic field symmetry properties, with possible completely antisymmetric behavior. However the symmetry properties are not determined by chirality alone. For this reason I proposed photo-magnetism as a more selective probe for chirality and started a new experiment to detect this effect in quantum dots using a Hall magnetometer. This research exhibited subtle dynamical effects of transport in ballistic Hall bars under irradiation and inspired later research on zero resistance states. I also looked for signatures of chirality in the transport properties of single chiral molecules. This led me to realize technically challenging experiments on transport through DNA, showing that conduction in DNA could be enhanced by connecting the molecules to a disconnected array of nanoparticles. Finally I developed a contact-Iess experiment to probe photo-transport in nanowires under visible illumination. This experiment can also probe chirality by detecting photo-transport under circularly-polarized Iight
Lesne, Edouard. "Non-Equilibrium Spin Accumulation Phenomena at the LaAlO3/SrTiO3(001) Quasi-Two-Dimensional Electron System." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066417/document.
Full textWe investigated the generation, manipulation, and detection of non-equilibrium spin accumulation in the nonmagnetic LaAlO3/SrTiO3 (LAO/STO) oxide heterostructure, which is the host of a quasi-two-dimensional electron system (q2DES). In electrical tunneling spin injection experiments, we made use of the (three-terminal) Hanle effect to probe the magnitude of spin accumulation at Co/LAO/STO interfaces. We report on large amplification effects of the spin signal, ascribed to spin-conserving sequential tunneling processes via localized electronic states of enhanced spin lifetimes. A substantial modulation of the spin signal, by electrostatic field-effect, evidences the successful generation of spin accumulation inside the q2DES. We further resorted to ferromagnetic resonance experiments in a cavity to adiabatically pump a spin current from a permalloy layer toward the LAO/STO interface. We find that the generated spin current is converted into a sizeable planar charge current within the q2DES. This is attributed to an inverse Edelstein effect deriving from a Rashba-like spin-orbit interaction, both of which are efficiently modulated by electrostatic field-effect. Hence, our findings expand the general field of interest from planar charge transport to the exploration of spin-dependent phenomena in a prototypical nonmagnetic conducting oxide channel. Additionally, we have also demonstrated that the critical thickness threshold for the onset of a q2DES at LAO/STO interfaces can be reduced to a single unit cell of LAO when resorting to various metal capping layers. It opens up a new field of investigation to tentatively identify the potential mechanisms driving the formation of the q2DES
Hackl, Andreas. "Quantum criticality and non-equilibrium dynamics in correlated electron systems." Aachen Shaker, 2009. http://d-nb.info/1001216466/04.
Full textPons, Nicolas. "Modélisation tridimensionnelle multibandes du transport quantique dans les transistors à nanofil." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10039/document.
Full textPerformances improvement of MOS transistors involves reduction of its dimensions. In a few years, the gate length of devices will reach sub-10 nm regime. At this scale, quantum effects become preponderant and considerably degrade electric performances of simple-gate transistors. The Gate-all-around nanowire transistor is an interesting alternative architecture to improve electrostatic control of the conduction channel. Despite the improvements made thanks to this architecture, the OFF-current remains disturbed by tunneling effect in source-drain direction. In order to decrease this current without decreasing the ON-current, we have studied the impact of local narrowing of transverse cross-section in drain side of the channel (notch-MOSFET architecture). To this purpose, we have developed a 3D simulator based on Non-equilibrium Green function formalism coupled self-consistently with Poisson equation. These simulations are performed in the effective mass approximation. Then we have studied holes transport in p-type nanowire transistors and the influence of an ionized impurity in the channel of these devices. The valence band complexity required six-band k∙p model development include into previously mentioned 3D simulator
Dziekan, Piotr. "Dynamics of far-from-equilibrium chemical systems : microscopic and mesoscopic approaches." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066402/document.
Full textMany nonlinear systems under non-equilibrium conditions are highly sensitive to internal fluctuations. In this dissertation, stochastic effects in some generic reaction-diffusion models are studied using two approaches of different precision. In the mesoscopic approach, evolution of the system is governed by the master equation, which can be solved numerically or used to set up kinetic Monte Carlo simulations. On the microscopic level, particle computer simulations are used. These two stochastic approaches are compared with deterministic, macroscopic reaction-diffusion equations.In the Introduction, key information about the different approaches is presented, together with basics of nonlinear systems and a presentation of numerical algorithms used.The first part of the Results chapter is devoted to studies on reaction-induced perturbation of particle velocity distributions in models of bistability and wave front propagation. A master equation including this perturbation is presented and compared with microscopic simulations.The second part of the Results deals with pattern formation in reaction-diffusion systems in the context of developmental biology. A method for simulating Turing patternsat the microscopic level using the direct simulation Monte Carlo algorithm is developed. Then, experiments consisting of perturbing segmentation of vertebrate embryo’s bodyaxis are explained using the Turing mechanism. Finally, a different possible mechanism of body axis segmentation, the “clock and wavefront” model, is formulated as a reaction-diffusion model
Abuaisha, Murad S. "Géothermie profonde : stimulation de la perméabilité par fracturation hydraulique dans un cadre thermo-poroélastique." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI016/document.
Full textThe application of the Hydraulic Fracturing (HF) technology to exploit geothermal energy from Hot Dry Rocks (HDR) reservoirs is addressed. HF is achieved by extensively pumping geothermal fluids to already existing fractured HDR reservoirs of low permeability. High fluid pressures are expected to drive cracks to evolve and connect. The newly created burgeoning hydraulic conduits should supposedly enhance the permeability of the existing HDR reservoirs. The flow rate/pressure values at which geothermal fluids should be pumped, as well as the pumping schedule to initiate HF, depend primarily on the existing geostatic conditions (geostatic stresses, initial HDR pressure and temperature) as well as on HDR fracture properties (initial mean fracture length, mean fracture aperture, density and orientational distribution of fractures). While these components, in addition to their effects on borehole stability, are scrutinized in this research, focus is on the evolution during circulation processes of the fracture properties. A fracturing model that is capable of tracking fracture evolution in all possible spatial orientations is used to obtain the time course of the anisotropic permeability tensor. This evolving property is integrated into a domestic finite element code which is developed to solve thermo–poroelastic BVPs: emphasis is laid on the efficiency of the doublet flow technique where a fluid gains thermal energy by circulating through the HDR reservoir from the injection well to the production well. The spurious oscillations in the hyperbolic solutions of the approximated finite element approach that are commensal with the phenomenon of forced heat convection are healed/mitigated through several stabilization approaches
Sharma, Sushank. "Transition laminaire turbulent dans les couches limites supersoniques : différents scénarios et contrôle possible Control of oblique-type breakdown in a supersonic boundary layer employing streaks Turbulent flow topology in supersonic boundary layer with wall heat transfer Laminar-to-turbulent transition in supersonic boundary layer : : Effects of initial perturbation and wall heat transfer Effect of thermo-mechanical non-equilibrium on the onset of transition in supersonic boundary layers." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMIR16.
Full textDirect numerical simulations (DNS) of both adiabatic and isothermal (heated and cooled) supersonic boundary layers are performed. Two different transition scenarios, namely the Oblique-type breakdown and the By-pass transition are presented in detail. For the oblique-type transition scenario, the results show that the control modes with four to five times the fundamental wavenumber are beneficial for controlling the transition. In the first region, after the control-mode forcing, the beneficial mean-flow distortion (MFD) generated by inducing the control mode is solely responsible for hampering the growth of the fundamental-mode. Globally, the MFD and the three-dimensional part of the control contribute equally towards controlling the oblique breakdown. Effects of physical parameters like wall-temperature, perturbation intensity and baseflow are investigated for the By-pass transition. The results regarding the by-pass scenario reveal that increasing the perturbation intensity moves the transition onset upstream and also increases the length of the transition region. Additionally, below 1% perturbation levels, wall-cooling stabilizes the flow while inverse happens at higher values. The existence of the thermo-mechanical non-equilibrium advances the onset of transition for the heated cases while the cooled wall behaves in the opposite sense. The analyses of the turbulent boundary layer show that the thermal factors influence the topology and inclination of the vortical structures. Moreover, regarding the heat flux, different transfer process is dominant in the near-wall region for the cooled wall
Fonseca, James Ernest. "Accurate treatment of interface roughness in nanoscale double-gate metal oxide semiconductor field effect transistors using non-equilibrium Green's functions." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1176318345.
Full textInkaya, Ugur Yigit. "Ratchet Effect In Mesoscopic Systems." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606929/index.pdf.
Full textttiker formalism of mesoscopic quantum transport is presented.
Van, Roermund Raphaël. "Étude théorique du transport hors d'équilibre dans les boîtes quantiques Kondo." Grenoble, 2010. http://www.theses.fr/2010GRENY050.
Full textIn the absence of exact theoretical methods, many questions related to the non-equilibrium Anderson model have remained unsolved and are at the origin of an intense research activity. In this thesis I discuss transport through quantum dots put in the Kondo regime by means of an equations-of-motion method that was developed in order to account for the non-equilibrium effects and in particular the decoherence of the virtual spin-flip processes involved in the Kondo effect. I compare my results to previous approximations and show the improvements brought by the new decoupling scheme, which solves pathologies at the particle-hole symmetric point and enables the description of the system over a wide range of parameters. A decoherence rate is derived for the excitations which is shown to involve a crossover from the strong- to the weak-coupling regime when either the temperature or the bias voltage or the magnetic field is increased. In the light of this result, I conclude on the applicability of the present equations-of-motion scheme out of equilibrium. I also discuss observables out of equilibrium; the differential conductance exhibits a zero-bias peak reaching a maximum value G = 2e^2/h. Its low-energy behavior turns out to be universal after the bias voltage is normalized by the Kondo temperature. I finally show that a finite magnetic field splits the zero-bias peak in the differential conductance. The actual distance between the peaks is discussed in the light of recent experiments for which I give a phenomenological explanation. A new experimental setup is proposed in order to verify my assumptions
Zazunov, A. "Phénomènes cohérents dans le transport électronique à travers un conducteur moléculaire." Habilitation à diriger des recherches, Université de la Méditerranée - Aix-Marseille II, 2007. http://tel.archives-ouvertes.fr/tel-00175417.
Full textL'emphase à été mise sur la détection des signatures les plus marquantes du transport cohérent à travers les molécules, ainsi que sur la compréhension des problèmes de corrélations (problème à N corps) sur la dynamique de ces systèmes, provenant des degrés de liberté internes (vibrations, spin,...) du conducteur et affectant le passage du courant.
En ce qui concerne le transport dans le régime normal à travers une molécule qui vibre (un nanotube de carbone suspendu par ses extrémités), nous avons procédé à une étude détaillée de la conductance différentielle négative (CDN) qui est observée dans ces dispositifs. En supposant des contacts tunnel, tel que les électrons qui s'échappent dans les bornes effectivement perdent leur cohérence de phase (c'est-à-dire à haute température),
nous avons dérivé les équations cinétiques dans lesquelles la nature quantique de l'interaction électron-phonon au sein du point quantique moléculaire est prise en compte sans approximations (formation de polaron sur le point quantique moléculaire). Le fait que la conductance différentielle soit positive ou négative dépend de la position du niveau polaronique et de l'occupation des pics satellites associés au nombre d'occupation des phonons, qui sont compris entre la tension de source et de drain des électrodes. La CDN
apparaît lorsque deux de ces pics satellites entrent en compétition dans le transport, et constitue une signature des effets hors équilibres associés au vibrations de la molécule. Nous avons clairement montré que pour des couplages tunnels asymétriques (situation qui correspond à la géométrie des expériences sur le domaine), on observe un CDN pour un vaste domaine de paramètres. Nous avons également exploré les effets de navette électronique, ou
le déplacement de la molécule entre en compte dans l'Hamiltonien tunnel, qui peuvent être détectés en regardant l'asymétrie des courbes courant tension. Bien que le mécanisme de navette tend à renforcer la CDN, il n'est toutefois pas suffisant pour y donner lieu sans hypothèses sur la valeur relative des couplages tunnels.
Nous avons également étudié le transport dans le régime normal à travers un point quantique moléculaire dans le cas d'un couplage fort aux contacts, mais loin du régime Kondo. En utilisant l'approche hors équilibre des fonctions de Green dans la représentation du polaron, nous sommes allés au delà du régime perturbatif pour calculer la caractéristique courant tension dans le régime de couplage électron-phonon intermédiaire. Nous avons montré qu'en accroissant le couplage tunnel au contacts, les corrélations associées au nuage de polaron deviennent très importantes à haute température, et donnent lieu à une réduction dramatique de l'élargissement des pics la densité d'états de la molécule. Nous proposons une détection de ces phénomènes par la mesure de la conductance différentielle, tout en variant la température locale de la molécule (nanotube de carbone). On note qu' en présence d'un environnement dissipatif les pic satellites dus aux phonons devraient acquérir un élargissement additionnel. L'inclusion des effets d'amortissement des modes phononiques constituerait une extension de ce travail.
Dans cette thèse, nous avons également abordé le problème du transport cohérent en présence de phonons, dans un système moléculaire connecté à des contacts supraconducteurs. Nous avons calculé le courant DC (partie du courant stationnaire) pour toutes les valeurs de la tension à l'aide de l'approche des fonctions de Green Keldysh, pour une fréquence de vibration arbitraire, mais dans le régime du couplage faible électron-phonon. Nos principaux résultats sont les suivants : i) dans le régime sous le gap $eV<\Delta$, les processus de réflexions multiples d'Andreev (MAR) sont accompagnés de processus d'émission/absorption de phonons et donne lieu à une structure très riche près des valeurs de tension ou le nombre
de réflexions d'Andreev changent d'une unité (ces tensions sont appelées les « MAR onsets »). On observe alors un effet pair impair ou le courant est augmenté/diminué suivant la transition de « MAR onset » (entre pair/impair et vice versa). Ces phénomènes trouvent un interprétation physique en comparant avec la théorie de la diffusion de Buttiker-Landauer, adaptée au contacts supraconducteurs, une théorie connue sous le nom d' « échelle de MAR ». A l'équilibre $V=0$, nous avons obtenu des résultats analytiques pour le courant Josephson dans la limite adiabatique ou la fréquence de vibration est faible comparée au gap supraconducteur, qui est interprétée en terme des états liés d'Andreev avec une transparence aux contacts renormalisée par les phonons. Pour le futur, une extension de cette théorie au calcul du bruit (fonction de corrélation courant-courant) est envisagée. Le bruit peut en effet procurer une information supplémentaire sur la charge transmise à travers la jonction, et il serait intéressant d'étudier l'effet des phonons dans ce cadre.
Nous avons également considéré le cas des contacts supraconducteurs, mais cette fois pour les interactions fortes, et uniquement à l'équilibre ou le courant Josephson dépend de la différence de phase entre les deux supraconducteurs. Cette fois on s'intéresse à un diagnostique sur l'état des phonons sur le point quantique moléculaire. Nous trouvons que pour le régime de faible couplage tunnel, des états non-classiques de type « chat de Schrodinger » (une superposition d'états cohérents opposés) sont associés aux états du courant et donc aux liés d'Andreev dans la jonction. Ces états non classiques peuvent être
explicités en procédant à une mesure projective du courant. Pour des contacts transparents, nous avons montré que l'effet Josephson génère des fluctuations de phonon cohérentes, et induit des états quantiques « comprimés » de phonon, analogues aux états « comprimés » de photons en optique quantique : l'impulsion canoniquement conjuguée à la distorsion de la molécule possède des fluctuations inférieures a la valeur minimale habituelle de fluctuations du point zéro. La compression d'états de phonons s'observe pour une grande plage de paramètres : elle est contrôlée par la différence de phase et devient maximale près de la transition de polaron. La détection expérimentale de tels états comprimés pourrait être effectuée en nanoélectronique à l'aide de nanotubes suspendus. Il faudrait recourir à un diagnostique optique tel que l'effet Raman résonant, pour démonter l'existence de ces états de phonons non-classiques.
Une autre manière d'explorer les phénomènes cohérents dans le cadre du transport Josephson
est d'étudier les situations ou les degrés de liberté de spin des électrons du point quantique moléculaire et des électrodes sont importants. Nous avons donc calculé le courant Josephson
à travers un point quantique moléculaire doté d'un grand spin, qui possède une interaction d'échange avec l'électron du point quantique. Ce couplage d'échange peut donner lieu à une transition à l'état pi de la jonction (relation courant phase opposée par rapport a une jonction normale, de phase 0). La contribution relative du courant provenant des états liés d'Andreev
et du continuum détermine si la jonction est dans l'état 0 ou l'état pi. Un débouché possible de cette étude est d'étudier les effets de décohérence, et de rétroaction du supercourant sur la dynamique du spin moléculaire.
Dans un autre contexte, les effets de spin associé au courant Josephson ont été étudiés pour un point quantique possédant plusieurs nivaux, et sujet à l'interaction spin orbite Rashba et Dresselhaus. Pour un point quantique ne possédant qu'un seul niveau les effet du couplage spin orbite sont inexistants en l'absence d'un champ magnétique externe. En présence de ce dernier, le courant de ce point quantique possède des oscillations de type Datta Das en fonction du paramètre de couplage spin orbite multiplié par la longueur du point quantique.
Ces oscillations ont une amplitude de quelques dixièmes du courant nominal Josephson, et pourraient donc être observées expérimentalement. Le cas d'un point quantique possédant plusieurs niveaux est plus intéressant. Pour un point quantique à deux niveaux en particulier,
Le courant possède une dépendance sur le couplage spin orbite même en l'absence de champ magnétique. Le supercourant possède des maxima et des minima marqués pour certaines valeurs de ce couplage. Leur observation constituerait une première évidence du fonctionnement d'un transistor à effet spin orbite dont les bornes sont supraconductrices.
Dans le futur il serait intéressant d'inclure les interactions Coulombiennes sur le dot.
Nous avons développé en parallèle une théorie pour modéliser un bit quantique basé sur les états liés d'Andreev : un dispositif constitué d'un SQUID (dispositif d'interférométrie supraconducteur) et d'un contact ponctuel supraconducteur, combinant donc un circuit macroscopique et microscopique. Le contact ponctuel – qui implique une transparence
elevée entre les contacts, peut être vu comme un point quantique qui contient deux états fermioniques localisés, à leur tout couplés à la dynamique de la phase supraconductrice
(un mode bosonique local). Nous avons étudié la décohérence de ce bit quantique d'Andreev, associée à un couplage des électrons des contacts avec des modes de phonons acoustiques. La nature fermionique des nivaux d'Andreev n'affecte pas le pilotage du bit quantique, mais elle joue un rôle important en ce qui concerne sa décohérence : la relaxation et le déphasage induit
suivent une loi de puissance dans le temps plutôt qu'une exponentielle. De plus, nous avons trouvé que le taux de transition entre les nivaux du bit quantique, induit par les transition phononiques est réduit de manière considérable comparé au taux de transition électron-phonon dans les contacts : l'étalement de la fonction d'onde de ses niveaux dans les contacts
réduit l'espace de phase disponible pour ces transitions assistées par les phonons.
Dans une étude séparée, nous nous sommes intéressé à la mesure du bruit à haute fréquence ainsi qu'a celle des moments supérieurs du courant, à l'aide d'un circuit résonant en présence de dissipation. Le circuit résonant est couplé à un circuit mésoscopique placé dans le régime cohérent. L'information sur les moments supérieurs du courant est codée dans les histogrammes de la charge du condensateur du circuit résonant. La dissipation est prise en compte par le modèle de Caldeira Leggett, et il est essentielle de l'inclure pour obtenir des fluctuations de charge (donc un bruit mesuré) finies. Nous identifions également quelle
Combinaison des corrélateurs de courant entrent dans l'expression du troisième moment mesuré. Ce dernier fait appel à la même susceptibilité généralisée que pour le bruit mesuré, mais elle ne diverge pas dans la limite d'un circuit non dissipatif. Les prédictions sur la mesure de ces quantités sont testées pour le cas du bruit émanant d'un contact ponctuel.
Nguyen, Thai Phu. "Conception et application d'un modèle de l'information routière et ses effets sur le trafic." Phd thesis, Université Paris-Est, 2010. http://tel.archives-ouvertes.fr/tel-00626631.
Full textKaiser, Vojtech. "The Wien Effect in Electric and Magnetic Coulomb systems - from Electrolytes to Spin Ice." Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0942/document.
Full textA Coulomb gas or fluid comprises charged particles that interact via the Coulomb interaction. Examples of a Coulombic systems include simple and complex electrolytes together with magnetic monopoles in spin ice. The long-range nature of the Coulomb interaction leads to a rich array of phenomena.This thesis is devoted to the study of the non-equilibrium behaviour of lattice based Coulomb gases and of the quasi-particle excitations in the materials known as spin ice which constitute a Coulomb gas of magnetic charges. At the centre of this study lies the second Wien effect which describes the linear increase in conductivity when an electric field is applied to a weak electrolyte. The conductivity increases due to the generation of additional mobile charges via a field-enhanced dissociation from Coulombically bound pairs.The seminal theory of Onsager gave a detailed analysis of the Wien effect. We use numerical simulations not only to confirm its validity in a lattice Coulomb gas for the first time but mainly to study its extensions due to the role of the ionic atmosphere and field-dependent mobility. The simulations also allow us to observe the microscopic correlations underlying the Wien effect.Finally, we look more closely at the emergent gas of monopoles in spin ice—the magnetolyte. The magnetic behaviour of spin ice reflects the properties of the Coulomb gas contained within. We verify the presence of the Wien effect in model spin ice and in the process predict the non-linear response when exposed to a periodic driving field, or to a field quench using Wien effect theory. We use a straightforward extension of the lattice Coulomb gas simulations to refine our predictions. It is a highly unusual result to find an analytic theory for the non-equilibrium behaviour of a highly frustrated system beyond linear response
Solminihac, Florence de. "Effets de perturbations magnétiques sur la dynamique de la barrière de transport dans un Tokamak : modélisation et simulations numériques." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4743/document.
Full textIn this PhD thesis we study the impact of resonant magnetic perturbations on the transport barrier dynamics in a tokamak. In this goal we have performed turbulence tridimensional numerical simulations in the edge plasma of a tokamak, which reproduced the experimental results observed in different tokamaks. In the improved confinement regime (H mode), the transport barrier is not stable : it does relaxation oscillations, which share common features with the ``Edge Localized Modes'' (ELMs). These ELMs both have advantages and drawbacks. On the one hand, they enable to push away the impurities present in the plasma core. But on the other hand, the thermal load induced on the wall during an ELM can damage the first wall materials. For this reason, they must be controlled. This PhD thesis belongs to the frame of the ITER project, which is today in construction in France. On ITER the ELMs control will be compulsory due to the quantity of energy released. Among the different ways of controlling the ELMs, the resonant magnetic perturbations (RMPs) seem promising. These resonant magnetic perturbations are created by external coils. We consider the TEXTOR tokamak case and we consider two configurations for the external coils : first, a resonant magnetic perturbation with several harmonics, which enables to have a stochastic zone at the plasma edge when the magnetic island chains overlap ; then, a resonant magnetic perturbation with a single harmonic, which therefore creates a single magnetic island chain. In this PhD thesis, we focus on the non-axisymmetric equilibrium created in the plasma by the resonant magnetic perturbation
Nadimi, Ebrahim. "Quantum Mechanical and Atomic Level ab initio Calculation of Electron Transport through Ultrathin Gate Dielectrics of Metal-Oxide-Semiconductor Field Effect Transistors." Doctoral thesis, Universitätsbibliothek Chemnitz, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200800477.
Full textDie vorliegende Arbeit beschäftigt sich mit der Berechnung von Tunnelströmen in MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors). Zu diesem Zweck wurde ein quantenmechanisches Modell, das auf der selbstkonsistenten Lösung der Schrödinger- und Poisson-Gleichungen basiert, entwickelt. Die Gleichungen sind im Rahmen der EMA gelöst worden. Die Lösung der Schrödinger-Gleichung unter offenen Randbedingungen führt zur Berechnung von Ladungsverteilung und Lebensdauer der Ladungsträger in den QBSs. Der Tunnelstrom wurde dann aus diesen Informationen ermittelt. Der Tunnelstrom wurde in verschiedenen Proben mit unterschiedlichen Oxynitrid Gatedielektrika berechnet und mit gemessenen Daten verglichen. Der Vergleich zeigte, dass die effektive Masse sich sowohl mit der Schichtdicke als auch mit dem Stickstoffgehalt ändert. Im zweiten Teil der vorliegenden Arbeit wurde ein atomistisches Modell zur Berechnung des Tunnelstroms verwendet, welche auf der DFT und NEGF basiert. Zuerst wurde ein atomistisches Modell für ein Si/SiO2-Schichtsystem konstruiert. Dann wurde der Tunnelstrom für verschiedene Si/SiO2/Si-Schichtsysteme berechnet. Das Modell ermöglicht die Untersuchung atom-skaliger Verzerrungen und ihren Einfluss auf den Tunnelstrom. Außerdem wurde der Einfluss einer einzelnen und zwei unterschiedlich positionierter neutraler Sauerstoffleerstellen auf den Tunnelstrom berechnet. Zug- und Druckspannungen auf SiO2 führen zur Deformationen in den chemischen Bindungen und ändern den Tunnelstrom. Auch solche Einflüsse sind anhand des atomistischen Modells berechnet worden
Iwan, Bianca. "Creating and Probing Extreme States of Materials : From Gases and Clusters to Biosamples and Solids." Doctoral thesis, Uppsala universitet, Molekylär biofysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-180997.
Full textAmeli, Mostafa. "Heuristic Methods for Calculating Dynamic Traffic Assignment Simulation-based dynamic traffic assignment: meta-heuristic solution methods with parallel computing Non-unicity of day-to-day multimodal user equilibrium: the network design history effect Improving traffic network performance with road banning strategy: a simulation approach comparing user equilibrium and system optimum." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSET009.
Full textTransport systems are dynamically characterized not only by nonlinear interactions between the different components but also by feedback loops between the state of the network and the decisions of users. In particular, network congestion affects both the distribution of local demand by modifying route choices and overall multimodal demand. Depending on the conditions of the network, they may decide to change for example their transportation mode. Several equilibria can be defined for transportation systems. The user equilibrium corresponds to the situation where each user is allowed to behave selfishly and to minimize his own travel costs. The system optimum corresponds to a situation where the total transport cost of all the users is minimum. In this context, the study aims to calculate route flow patterns in a network considering different equilibrium conditions and study the network equilibrium in a dynamic setting. The study focuses on traffic models capable of representing large-scale urban traffic dynamics. Three main issues are addressed. First, fast heuristic and meta-heuristic methods are developed to determine equilibria with different types of traffic patterns. Secondly, the existence and uniqueness of user equilibria is studied. When there is no uniqueness, the relationship between multiple equilibria is examined. Moreover, the impact of network history is analyzed. Thirdly, a new approach is developed to analyze the network equilibrium as a function of the level of demand. This approach compares user and system optimums and aims to design control strategies in order to move the user equilibrium situation towards the system optimum
Buguin, Arnaud. "Couches limites tridimensionnelles en hypersonique : effets du déséquilibre et du gradient d'entropie." Toulouse, ENSAE, 1997. http://www.theses.fr/1997ESAE0003.
Full textSchubert, Sven. "Stochastic and temperature-related aspects of the Preisach model of hysteresis." Doctoral thesis, Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-70798.
Full textThe aim of this thesis is to investigate the Preisach model in regard to stochastically driving and temperature-related aspects. The Preisach model is a phenomenological model for systems with hysteresis which is often successfully applied. Hysteresis is a widespread phenomenon which is observed in nature and the key feature of certain technological applications. Further, it contributes to phenomena of interest in social science and economics as well. Prominent examples are the magnetization of ferromagnetic materials in an external magnetic field or the adsorption-desorption hysteresis observed in porous media. Hysteresis involves the development of a hysteresis memory, and multistability in the interrelations between external driving fields and system response. In the first part, we mainly investigate the response of Preisach hysteresis models driven by stochastic input processes with regard to autocorrelation functions to quantify the influence of the system’s memory. Using rigorous methods, it is shown that the development of a hysteresis memory is reflected in the possibility of long-time tails in the autocorrelation functions, even for uncorrelated driving fields. In the case of uncorrelated driving, these long-time tails in the autocorrelations of the system’s response are determined only by the tails of the involved densities. They will be observed if there are broad Preisach densities assigning a high weight to elementary loops of large width and narrow input densities such that rare extreme events of the input time series contribute significantly to the output for a long period of time. Afterwards, these results are extended by simulations to driving fields which themselves show correlations. It is shown that the autocorrelation of the output does not decay faster than the autocorrelation of the input process. Further, there is a possibility that long-term memory in the hysteretic response is more pronounced in the case of uncorrelated driving than in the case of correlated driving. The behavior of the output probability distribution at the saturation values is quite universal. It is not affected by the presence of correlations and allows conclusions whether the input density is much more narrow than the Preisach density or not. Moreover, the existence of effective Preisach densities is shown which define equivalence classes of systems of input and Preisach densities which lead to realizations of the same output variable. The asymptotic behavior of an effective Preisach density determines the asymptotic correlation decay of the system’s response in the case of uncorrelated driving. In the second part, temperature-related effects are considered. It is reviewed how the non-equilibrium Preisach model in its micromagnetic picture can be related to temperature within the framework of extended irreversible thermodynamics. The irreversible response of a ferromagnetic material, namely, Nickel nanoparticles in a fullerene matrix, is simulated. The model includes superparamagnetism where ferromagnetism breaks down at temperatures lower than the Curie temperature and the results are compared to experimental data. Furthermore, we adapt known results for the thermal relaxation of the system’s memory in the form of a front propagation in the Preisach plane derived basically from solving a master equation and by the use of a contradictory assumption. A closer look is taken at short time scales which dissolves the contradiction and shows that the known results apply, taking into account the fact that the dividing line propagation starts with an additional delay time depending on the front coordinates in the Preisach plane. Additionally, it is outlined how thermal relaxation behavior in the Preisach model of hysteresis can be studied using a Fokker-Planck equation. The latter is solved analytically in the non-hysteretic limit using eigenfunction methods. The results indicate a change in the relaxation behavior, especially on short time scales
Debreux, Claire. "Ségrégation intergranulaire du bore dans l'austénite d'un acier trempant au bore : étude par tomographie atomique et modélisation." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR066.
Full textBoron steels are defined by a high hardenability. This effect is related to the intergranular segregation of boron in austenite. In these steels, two mechanisms of boron segregation generally coexist: equilibrium segregation and non-equilibrium segregation. They have a different driving force and kinetics, and accordingly a different temperature and time dependence. Thus, depending on heat treatment conditions, the boron content at austenite grain boundaries fluctuates. The thesis aims at understanding the boron segregation at austenite grain boundaries according to heat treatment conditions. A heat treatment was studied: austenitization at 1000°C, followed by a quenching at 50°C/s up to 600°C where an isothermal holding is carried out. This study is divided in two parts. First, an experimental part with the interfacial boron quantification by Atom Probe Tomography (APT) analysis. Second, a numerical part with the development of a modeling of the segregation kinetics which integrates both types of boron segregation. Informations about what is happening in the grain and the grain boundary can be extracted from the modeling. Experimental measurements are carried out after a fast quenching (300°C/s) down to room temperature with the ambition of freezing the studied state. This quench leads to an austenite-martensite transformation. In this complex configuration, a correlative microscopy protocol was developed to prepare samples containing a Prior Austenite Grain Boundary (PAGB) for APT analysis. Experimental analysis show that other elements segregate at PAGBs in addition to boron (presence of C, P, Cr, V, Mo and Mn), as well as an absence of boron in martensitic lath boundaries. A study of APT and numerical results shows that quenching at 300°C/s does not allow the thermal state to be frozen, an enrichment of the interface during this quenching takes place. Finally, as expected, a non-monotonic variation of the boron atomic fraction at grain boundary has been observed both experimentally and numerically, for hold times greater than one second. However, time scale between numerical and experimental interfacial enrichment kinetics is divergent. This can comes from both an unsuitable set of numerical parameters and from the differences which exist between the model and the experimental reality (effects of co-segregation or the second quenching at 300°C/s, which are not taken into account by the model). Results are proving to be very encouraging, and open up numerous perspectives
Michel, Guillaume. "Parois et ondes de surface : dissipation, effet Doppler et interactions non linéaires." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEE038/document.
Full textIn this thesis, we study the impact of solid boudaries on surface waves. We first consider the dissipation caused by dynamical wetting. We experimentally show how the damping of surface waves evolves with the size of the meniscus and demonstrate that in perfect wetting it leads to a nonlinear behavior as soon as the meniscus oscillation amplitude compares to the thickness of the boundary layer. Secondly, we investigate energy exchanges through scales occuring when a surface wave reflects on an oscillating wall, the so-called generalized Doppler effect. We evidence the creation of Doppler-shifted waves, compute their amplitudes and illustrate how the continuous bouncing of surface waves on wavemakers may lead to self-similar spectra competing with the ones of wave turbulence. Finally, we focus on nonlinear interaction between surface waves. We prove that gravity waves can undergo triad resonances in confined geometry. Going beyond the consequencies of solid boundaries, we perform experiments on four-wave interactions in the gravity regime and describe large scales in capillary wave turbulence
Tyl, Clémence. "Study of the memory effect in atmospheric pressure townsend discharges in nitrogen with addition of oxidizing gas : temporally and spatially resolved electrical and optical characterizations." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30296.
Full textPlasma processes at atmospheric pressure using Dielectric Barrier Discharges (DBD) are a good alternative to low pressure non-thermal plasma processes for various applications such as surface treatment, thin-film coating, sterilization etc. Indeed, they can be operated without complex vacuum facilities and allow the treatment of large surfaces that can be implemented directly into assembly lines. However, DBDs are usually filamentary, leading to non-homogeneous depositions on the treated surfaces. In certain condition depending on the experimental parameters (geometry, gas nature, power supply, etc.), a homogeneous discharge can be obtained leading to a uniform surface treatment. Nevertheless, even in the homogeneous mode, the DBDs properties are not necessarily the same at any point on the discharge surface, because of the gas flow circulation in particular, but also in case of materials with a properties gradient, or in case of self-organization phenomena. In order to better characterize the spatial distribution of the discharge, a new local electrical diagnostic tool to measure the local current densities has been developed during this thesis. Indeed, electrical measurements are widely used to characterize the DBDs as they give access to various parameters such as the gas voltage, discharge current, dissipated power etc. However, the measured current is integrated on all the surface of the electrodes. To be able to measure the local currents, the 3×3 cm2 ground electrode from the discharge cell has been divided into 64 segments, and a data acquisition system has been developed in order to simultaneously acquire the 64 measured currents with a high enough sampling rate for the data processing. This new electrical diagnostic tool can be correlated in time and space with optical measurements with an intensified iCCD camera, coupled with optical filters, to obtain information on the densities of some species in the plasma. The aim of this thesis is to better understand to local power dissipation, and to refine the characterization of the involved species in the different discharge regimes, especially to obtain a homogeneous regime. Homogeneous DBDs are ignited by a Townsend breakdown. For a Townsend breakdown to occur, a production source of seed electrons is necessary between two discharges, when the electric field is lower than the breakdown voltage. This breakdown is related to a memory effect from one discharge to the following one, that is visible on the electrical measurements with a discharge current jump. The hypotheses on the memory effect origin can be separated into two categories.[...]
Hannaoui, Rachid. "Simulation par Dynamique Moléculaire des Propriétés de Transport (Masse et Chaleur) de Fluides Confinés." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3010/document.
Full textThe aim of this work was to study how a fluid confined in a low permeability porous medium (micro- and meso-porous) behaves concerning its properties of mass diffusion, thermal conductivity and thermal diffusion. For this purpose, non-equilibrium molecular dynamics simulations have been performed on simple binary mixtures placed in various thermodynamic conditions, confined in a porous medium of lamellar geometry of different types (structure-less or atomistic, more or less adsorbent) in __//_ and grand canonical ensembles. The results show that the effects of porous medium on transport properties are more pronounced when the pore size is small, the adsorption is strong and the temperature is low. The results allowed to evaluate these effects quantitatively. In addition, it has been found that the wall roughness has a major impact on the mass diffusion coefficient and a non negligible one on the thermal diffusion coefficient
Bertrand, Corentin. "Algorithme Monte-Carlo pour les systèmes quantiques à fortes interactions et hors d'équilibre en nanoélectronique." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY030.
Full textNon-equilibrium quantum many-body problems are attracting increasingly more attention in condensed matter physics. For instance, systems of interacting electrons submitted to an external (constant or varying) electric field are studied in nanoelectronics, and more recently in materials, for the search of novel non-equilibrium states of matter. In this thesis, we developed a new numerical generic method for these problems, and apply it to the Anderson impurity model. This model is a good representation of a quantum dot coupled to one or several leads, and gives rise at equilibrium to the Kondo effect --- a manifestation of Coulomb interactions within the dot. We apply our method to compute the collapse of the Kondo effect when the quantum dot is driven out of equilibrium by a voltage bias. Our method is based on a diagrammatic Quantum Monte Carlo (QMC) algorithm. The QMC is an optimized version of the algorithm of Profumo et al. [Phys. Rev. B 91, 245154 (2015)], which computes time-dependent observables or correlation functions as perturbation series in the interaction strength U. To address the problem of diverging series at large U, we constructed a robust resummation scheme which analyses the analytical structure of the series in the U complex plane, for proposing a tailor-made regularization method using a conformal transform of the complex plane. As a post-treatment, a Bayesian technique allows to introduce non-perturbative information to tame the exacerbation of error bars caused by the resummation. We emphasize the potential application to study non-equilibrium materials through "quantum embedding" schemes, such as the Dynamical Mean Field Theory (DMFT), which allow to study lattice models through solving a self-consistent impurity model
Wirnsberger, Peter. "Computer simulation and theoretical prediction of thermally induced polarisation." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/282988.
Full textBerrada, Salim. "Etude théorique de nouveaux concepts de nano-transistors en graphène." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01059811.
Full textFuchs, Florian. "Feldeffekttransistoren auf Basis von Kohlenstoffnanoröhrchen: Vergleich zwischen atomistischer Simulation und Bauelementesimulation." Master's thesis, Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-157276.
Full textBorazjani, Sara. "Analytical modelling of two-phase multi-component flow in porous media with dissipative and non-equilibrium effects." Thesis, 2016. http://hdl.handle.net/2440/106453.
Full textThesis (Ph.D.) (Research by Publication) -- University of Adelaide, Australian School of Petroleum, 2016.
Viddal, Candice April Harder. "Non-equilibrium effects in nanoparticulate assemblies, bond-disordered ferromagnets, and collections of two-level subsystems." 2009. http://hdl.handle.net/1993/3123.
Full textFebruary 2009
Gehlen, Sebastian von [Verfasser]. "Minimal stochastic models for non-equilibrium effects and atomic-scale friction phenomena / Sebastian von Gehlen." 2009. http://d-nb.info/1000291197/34.
Full textSaldivarMassimi, Heriberto, and 何聖廷. "Numerical Study of Rarefaction Effects and Thermochemical Non-equilibrium Problems on Hypersonic Flows around Space Vehicles." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/13314730350830538638.
Full text國立成功大學
航空太空工程學系碩博士班
101
The present work focuses on the problem of aerothermodynamics of space vehicles with rounded edges on the hypersonic segment of the flight trajectory. Firstly, the in-house Navier-Stokes solver, UNIC-UNS code, with the slip boundary condition is used to simulate the flows around a spherical- nosed cylinder at different Knudsen numbers and Mach numbers, and compared with DSMC computations for validation. The Navier-Stokes simulations are in good agreement with that of DSMC. The hypersonic flows over the European eXPErimental Re-entry Test-bed (EXPERT) model are then simulated for a wide range of flow regimes, which correspond to the expected descent trajectory with allowance for rarefaction and thermochemical nonequilibrium. Three dimensional CFD analyses are presented for the complete geometry of the capsules considering the air dissociation and its effects on the flow structure and on the force and thermal loads for the hypersonic segment of the flight as a precursor to the future studies and to provide the scientific community with quality data that can be used to improve tools for the design of hypersonic vehicles.
Carvalho, Vítor Manuel Costa. "Non-Keynesian Effects of Fiscal Policy in a New-Keynesian General Equilibrium Model for the Euro Area." Doctoral thesis, 2009. https://repositorio-aberto.up.pt/handle/10216/112855.
Full textCarvalho, Vítor Manuel Costa. "Non-Keynesian Effects of Fiscal Policy in a New-Keynesian General Equilibrium Model for the Euro Area." Tese, 2009. https://repositorio-aberto.up.pt/handle/10216/112855.
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