Дисертації з теми "Coherent structures dynamics"
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Petviachvili, Nikolai. "Coherent structures in nonlinear plasma dynamics /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Повний текст джерелаDavis, J. A. "Ultrafast coherent dynamics in semiconductor nano-structures." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598402.
Повний текст джерела劉國強 and Kwok-keung Lau. "Interactions of coherent structures in annular jets." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31232632.
Повний текст джерела周健強 and Kin-keung Chow. "Acceleration of coherent structures in free shear layer." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31240069.
Повний текст джерелаHarter, Braxton Nicholas. "Lagrangian Coherent Structures in Vortex Ring Formation." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1565828293505214.
Повний текст джерелаLoewen, Stuart Reid. "Statistics and dynamics of coherent structures on turbulent grid-flow." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27437.
Повний текст джерелаScience, Faculty of
Physics and Astronomy, Department of
Graduate
Sundkvist, David. "Space Plasma Dynamics : Instabilities, Coherent Vortices and Covariant Parametrization." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6051.
Повний текст джерелаBudanur, Nazmi Burak. "Exact coherent structures in spatiotemporal chaos: From qualitative description to quantitative predictions." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54445.
Повний текст джерелаEickemeyer, Felix. "Ultrafast dynamics of coherent intersubband polarizations in quantum wells and quantum cascade laser structures." Doctoral thesis, [S.l.] : [s.n.], 2002. http://dochost.rz.hu-berlin.de/dissertationen/eickemeyer-felix-2002-07-03.
Повний текст джерелаHiggins, David. "Dynamics and statistical features of coherent plasma structures in the SOL of a tokamak." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57731/.
Повний текст джерелаTenerani, Anna. "Dynamics of ion-scale coherent magnetic structures and coupling with whistler waves during substorms." Paris 6, 2012. http://www.theses.fr/2012PA066473.
Повний текст джерелаA new model of the self-consistent coupling between low frequency, ion-scale coherent magnetic structures and high frequency whistler waves is proposed in order to interpret space data gathered by Cluster satellites during substorm events, in the night sector of the Earth’s magnetosphere. The coupling provides a mechanism to spatially confine and transport whistler waves by means of a highly oblique, propagating nonlinear carrier wave. The present study relies on a combination of data analysis of original in situ measurements, theoretical modeling and numerical investigation. During substorms, the magnetosphere undergoes strong magnetic and electric field fluctuations ranging from low frequencies, of the order or less than the typical ion-time scales, to higher frequencies, of the order or higher than the typical electron time-scales. To understand basic plasma physical processes which characterize the magnetosphere dynamics during substorms an analysis of whether, and by which mechanism, waves occurring at these different time scales are coupled, is of fundamental interest. Low frequency magnetic structures are commonly detected in environments such as the magnetosheath and the solar wind, as well as in the dusk magnetosphere, possibly correlated with higher frequency whistler waves. In this Thesis it is shown that similar magnetic structures, correlated with whistler waves, are observed in the magnetospheric plasma sheet during substorms. The interesting question arises as to how the inhomogeneity associated with such magnetic structures affects the propagation of higher frequency waves. The Cluster mission, thanks to its four satellites in tetrahedron configuration and high temporal resolution measurements, provides a unique opportunity on the one hand to explore the spatial structure of stationary and propagating perturbations observed at low frequencies and on the other hand to study dynamics occurring at higher temporal scales, via whistler mode waves. With regard to this, I will describe the Cluster spacecraft detection of large amplitude whistler wave packets inside coherent ion-scale magnetic structures embedded in a fast plasma flow during the August 17th 2003 substorm event. In this period the Cluster satellites were located in the plasma sheet region and separated by a distance which is less than the magnetotail typical ion-scale lengths, namely the ion gyroradius and the ion inertial length. The observed whistler emissions are correlated with magnetic field structures showing magnetic depletions associated with density humps. As a first step, the latter have been modeled as one dimensional nonlinear slow waves which spatially confine and transport whistlers, in the framework of a two-fluid approximation. This schematic model is investigated through a theoretical and numerical study by means of a two-fluid code, and it is shown that the proposed model goes quite well with data interpretation. Its possible role in substorm dynamics is also discussed. This new trapping mechanism, studied here by using a highly oblique slow magnetosonic soliton as a guide for whistler waves, is of more general interest beyond the specific context of the observations reported in this Thesis. Other nonlinear structures showing similar features, for example highly oblique nonlinear Alfvén waves or kinetic Alfvén waves in high beta plasmas, can in principle act as wave carriers. The model proposed provides an explanation for the recurrent detection of whistlers inside ion-scale magnetic structures which is alternative to usual models of stationary magnetic structures acting as channels. Moreover, the study described in this Thesis addresses more general questions of basic plasma physics, such as wave propagation in inhomogeneous plasmas and the interaction between wave modes at different temporal scales
Nichols, Andrew. "Free surface dynamics in shallow turbulent flows." Thesis, University of Bradford, 2013. http://hdl.handle.net/10454/7345.
Повний текст джерелаFuchert, Golo [Verfasser], and Ulrich [Akademischer Betreuer] Stroth. "Dynamics and structure analysis of coherent turbulent structures at the boundary of toroidally confined plasmas / Golo Fuchert. Betreuer: Ulrich Stroth." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2014. http://d-nb.info/105810621X/34.
Повний текст джерелаEl, Aouni Anass. "Lagrangian coherent structures and physical processes of coastal upwelling." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0146.
Повний текст джерелаStudying physical processes of an upwelling system is essential to understand its present variability and its past and future changes. This thesis presents an interdisciplinary study of the coastal upwelling system from different satellite acquired data, with the main focus placed on the North West African (NWA) upwelling system. This interdisciplinary study covers (1) the problem of the automatic identification and extraction of the upwelling phenomenon from biological and physical satellite observations. (2) A statistical study of the spatio-temporal variation of the NWA upwelling throughout its extension and different upwelling indices. (3) A Study of the nonlinear relationships between the surface mixing and biological activity in the upwelling regions. (4) Lagrangian studies of coherent eddies; their physical properties and automatic identification. (5) The study of transport made by Lagrangian eddies off the NWA Upwelling and their impact on the open ocean. [...]
Rypina, Irina I. "Lagrangian Coherent Structures and Transport in Two-Dimensional Incompressible Flows with Oceanographic and Atmospheric Applications." Scholarly Repository, 2007. http://scholarlyrepository.miami.edu/oa_dissertations/14.
Повний текст джерелаGiammanco, Raimondo. "Numerical study of coherent structures within a legacy LES code and development of a new parallel frame work for their computation." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210975.
Повний текст джерелаIndeed, recently had been suggested that separating and understanding the the different physical behavior of Coherent Structures and "uncoherent" background might very well be the key to understand and predict Turbulence. Available understanding of Coherent Structures shows that their size is considerably larger than the turbulent macro-scale, making permissible the application of Large Eddy Simulation to their simulation and study, with the advantage to be able to study their behavior at higher Re and more complex geometry than a Direct Numerical Simulation would normally allow. Original purpose of the present work was therefore the validation of the use of Large Eddy Simulation for the study of Coherent Structures in Shear-Layer and the its application to different flow cases to study the effect of the flow topology on the Coherent Structures nature.
However, during the investigation of the presence of Coherent Structures in numerically generated LES flow fields, the aging in house Large Eddy Simulation (LES) code of the Environmental & Applied Fluid Dynamics Department has shown a series of limitations and shortcomings that led to the decision of relegating it to the status of Legacy Code (from now on indicated as VKI LES legacy code and of discontinuing its development. A new natively parallel LES solver has then been developed in the VKI Environmental & Applied Fluid Dynamics Department, where all the shortcomings of the legacy code have been addressed and modern software technologies have been adopted both for the solver and the surrounding infrastructure, delivering a complete framework based exclusively on Free and Open Source Software (FOSS ) to maximize portability and avoid any dependency from commercial products. The new parallel LES solver retains some basic characteristics of the old legacy code to provide continuity with the past (Finite Differences, Staggered Grid arrangement, Multi Domain technique, grid conformity across domains), but improve in almost all the remaining aspects: the flow can now have all the three directions of inhomogeneity, against the only two of the past, the pressure equation can be solved using a three point stencil for improved accuracy, and the viscous terms and convective terms can be computed using the Computer Algebra System Maxima, to derive discretized formulas in an automatic way.
For the convective terms, High Resolution Central Schemes have been adapted to the three-dimensional Staggered Grid Arrangement from a collocated bi-dimensional one, and a system of Master-Slave simulations has been developed to run in parallel a Slave simulation (on 1 Processing Element) for generating the inlet data for the Master simulation (n - 1 Processing Elements). The code can perform Automatic Run-Time Load Balancing, Domain Auto-Partitioning, has embedded documentation (doxygen), has a CVS repository (version managing) for ease of use of new and old developers.
As part of the new Frame Work, a set of Visual Programs have been provided for IBM Open Data eXplorer (OpenDX), a powerful FOSS Flow visualization and analysis tool, aimed as a replacement for the commercial TecplotTM, and a bug tracking mechanism via Bugzilla and cooperative forum resources (phpBB) for developers and users alike. The new M.i.O.m.a. (MiOma) Solver is ready to be used again for Coherent Structures analysis in the near future.
Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished
Basley, Jérémy. "An Experimental Investigation on Waves and Coherent Structures in a Three-Dimensional Open Cavity Flow." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112245/document.
Повний текст джерелаA space-time study of a three-dimensional nonlinearly saturated open cavity flow is undertaken using time-resolved space-extended experimental data, acquired in both cross-stream and spanwise planes, in incompressible air and water flows. Through use of multiple modal decompositions in time and space, the waves and coherent structures composing the dynamics in the permanent regime are identified and characterised with respect to the instabilities arising in the flow.Effects of nonlinearities are thoroughly investigated in the impinging shear layer, regarding the self-sustained oscillations and their interactions with the inner-flow. In particular, the analysis conducted throughout the parameter space enlightens a global connection between the selection of locked-on modes and the amplitude modulation at the impingement and the mode switching phenomenon. Furthermore, observations of low frequencies interacting drastically with the shear layer flapping motion underline the existence of intrinsic coherent three-dimensional dynamics inside the cavity in spite of the shear layer disturbances.Linear stability analyses have demonstrated that centrifugal instabilities are at play along the main recirculation. The present investigation of the dynamics after onset of the saturation reveals numerous space-time coherent structures, whose properties are quantified and classified with respect to the underlying instabilities: travelling or standing spanwise waves. Finally, some patterns exhibited by the saturated structures suggest that the nonlinear mechanisms governing the mutations of the flow after the linear regime could gain more insight in the frame of amplitude equations
Akuetevi, Cataria Quam Cyrille. "Dynamics of turbulent western boundary currents at low latitudes, a numerical study." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU002/document.
Повний текст джерелаStrong western boundary currents are one of dominant features of the world oceans, also at low latitudes. They exhibit a turbulent dynamics and their region is a source of strong kinetic energy production and internal variability of the worlds oceans. Several places exists where the western boundary currents retrofect (i.e separation from the coast) and generate coherent structures as anticyclonic eddies, bursts and dipoles. The dynamics of turbulent western boundary currents has so far not been extensively studied in the viewpoint of turbulent boundary-layer theory. The approach followed in this thesis is to use a fine resolution (2.5km) reduced-gravity shallow water model to understand the turbulent boundary-layer processes and then apply these findings to the Ocean General Circulation Model NEMO in the Drakkar configuration (~10km). The case of the Somali Currentis considered for this application
Searle, Toby William. "Purely elastic shear flow instabilities : linear stability, coherent states and direct numerical simulations." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/28991.
Повний текст джерелаWesthoff, Andreas. "Spatial Scaling of Large-Scale Circulations and Heat Transport in Turbulent Mixed Convection." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-FD19-2.
Повний текст джерелаAcharya, Neelavara Shreyas. "Numerical study of transition to turbulence in plane Poiseuille flow in physical space and state space." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS019/document.
Повний текст джерелаThis thesis numerically investigates the dynamics of turbulence in plane Poiseuille flow driven by a fixed pressure gradient. The focus is especially on computations carried out within the minimal flow unit (M.F.U.). In the first part, turbulent simulations are carried out in spatially periodic channels. In the M.F.U. simulations, the turbulent activity appears to be localised near one wall and the long term dynamics features abrupt reversals. In the next part, we look numerically for exact coherent states in the M.F.U. system. Edge states, which are computed using bisection exhibit streamwise vortices and a single pair of streaks localised near only wall at all times. Different state space representations and phase portraits were constructed using appropriately chosen variables. The dynamics along a turbulent reversal is organised around transient visits to a subspace of (almost) symmetric flow fields. A nearly-symmetric exact travelling wave (TW) solution was found in this subspace. Stability analysis of the TW revealed that its unstable eigenvectors separate the state space into two symmetric basins. In the last part of this thesis, the self-similarity of the different non-trivial equilibrium flow regimes computed in this work, is addressed. Contrarily to most studies focusing on symmetric solutions, the present study suggests that inner scaling is relevant for the description of edge regimes as well although the self-similarity is not as satisfactory as for the turbulent regimes
Barbeiro, Iago de Carvalho. "Estruturas coerentes e modelos reduzidos para o escoamento ao redor de um cilindro no regime bidimensional periódico." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-07062013-111734/.
Повний текст джерелаThis thesis concerns the flow past a cylinder just after its first bifurcation, within its two-dimensional periodic regime. The approach is mainly theoretical, goes through experiments and is concluded by an important numerical part which complements the theory with evidences and illustrations. The main contributions are the analysis concerning the modal composition of the solution within the periodic regime and a method to identify eigenvectors of some linearizaton of the Navier-Stokes equation participating on a given solution. The bases spanned by the identified eigenvectors are employed in the projection of the Navier-Stokes equation and are central to the reduced models of this study. The numerical results for Re = 60 present two iterations of the process, with two bases of dimensions 12 e 24. The reduced models are numerically stable and their integration is many orders less costly than that of the full simulation. The time series of the modal coordinates and the eigenvectors bases allow the recomposition of the flow and its comparison with the full simulation results. The convergence analysis was based on the time averages, the Strouhal number values and the harmonic structure. Both reduced models have close correspondence with the asymptotic behavior of the flow and the convergent trend of the iterations is clear. The space and time symmetries of the harmonics have a simple representation within the structure of the models, therefore the identified bases can be understood as sets of coherent structures of the phenomenon.
Li, Qiang. "Direct and Large-Eddy Simulations of Turbulent Boundary Layers with Heat Transfer." Doctoral thesis, KTH, Mekanik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-41156.
Повний текст джерелаBressan, Filippo. "Large Eddy Simulation of turbulence around a scoured Bridge Abutment." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3511.
Повний текст джерелаIn this work the turbulent field developing in case of local erosion around a 45° wing-wall bridge abutment was investigated numerically. Three different scour conditions were considered: beginning of the process, logarithmic phase and equilibrium stage. The flow field was computed using a wall-resolving large eddy simulation (a simulation where the near-wall viscous sub-layer is directly resolved) and the bathymetric data were taken from physical experiments with an equivalent geometry. The dynamics of the coherent structures forming around the obstacle and inside the scour-hole was investigated and its influence on the modeling of the problem and on the erosion process was discussed. The analysis suggested that the full dynamics of the vortex system should be directly solved since simple eddy-viscosity models, as the k-ε model in RANS approach, were found to be not suited for this kind of problem and since high-order statistics were found to be important for the evolution of the local scour. The results of the present study may be helpful to formulate new physical-based local scour models to be used for practical evaluation of the scour depth around bridge abutments.
XXII Ciclo
1981
Blanc, Trevor Jon. "Analysis and Compression of Large CFD Data Sets Using Proper Orthogonal Decomposition." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5303.
Повний текст джерелаKitzhofer, Jens. "Volumetric measurements of the transitional backward facing step flow." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2011. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-79718.
Повний текст джерелаChoi, Ji Il. "Applications of nonlinear dynamics in atomic and molecular systems." Diss., Available online, Georgia Institute of Technology, 2007:, 2007. http://smartech.gatech.edu/bitstream/1853/16207/1/choi_jiil_200708_phd.pdf.
Повний текст джерелаTurgay Uzer, Committee Chair ; M. Raymond Flannery, Committee Member ; Chandra Raman, Committee Member ; Dragomir Davidovic, Committee Member ; Chongchun Zeng, Committee Member.
Allshouse, Michael R. "Detecting and analyzing coherent structures in two-dimensional dynamical systems." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/85540.
Повний текст джерелаSome pages landscape orientation. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 211-218).
The identification of coherent structures enhances the understanding of transport by complex flows such as those found at the ocean surface. The rapidly developing approach of Lagrangian Coherent Structures (LCSs) is based on the identification of codimension-1 structures that are locally the strongest repelling material surfaces in forwards or backwards-time over a given time window. Current theory and methods regarding LCSs are surveyed, and we present a modified algorithm for their detection, highlighting the pros and cons of the modified approach. One beneficial aspect of the modified approach is that it is possible to classify and advect LCSs through the time window. We apply the improved detection scheme as well as the classification to a high quality, validated simulation of ocean surface flow near the Ningaloo reef along the coast of Western Australia. This region is home to the longest fringing reef in Australia, a diverse marine environment, and a growing offshore drilling industry, and understanding the surface flows will enable better informed decisions to be made in this environmentally delicate domain. In addition to applying the LCS techniques, for the first time we account for the impact of surface winds on the LCS field by creating a hybrid current-wind velocity field. While the LCS approach is based on rigorous dynamical systems theory, its reliance on an accurate velocity field restricts potential ocean applications to simulations or regions with surface velocity measurements via systems like HF radar stations. An untapped resource is the data collected from float trajectories. With the goal of eventual application to these data sets, we develop a coherent structure detection algorithm utilizing sparse trajectory data. This new approach is based on the application of tools from braid theory, which produce a simplified perspective of the mixing of two-dimensional systems that enables rapid analysis. As a first application, our braid-based approach is applied to a periodically stirred system.
by Michael R. Allshouse.
Ph. D.
Tallapragada, Phanindra. "Identifying dynamical boundaries and phase space transport using Lagrangian coherent structures." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/28891.
Повний текст джерелаPh. D.
Squibb, Richard James. "Probing molecular structure and dynamics with coherent extreme ultraviolet and X-ray pulses." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/14731.
Повний текст джерелаMcclelland, Hunter Grant. "Towards Detecting Atmospheric Coherent Structures using Small Fixed-Wing Unmanned Aircraft." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/90667.
Повний текст джерелаDoctor of Philosophy
In a natural or man-made disaster, first responders depend on accurate predictions of where the wind might carry hazardous material. A mathematical theory of Lagrangian Coherent Structures (LCS) has shown promise in ocean environments to improve these predictions, and the theory is also applicable to atmospheric flows near the Earth’s surface. This dissertation presents both theoretical and experimental research efforts towards employing small fixed-wing unmanned aircraft systems (UAS) to detect coherent structures in the Atmospheric Boundary Layer (ABL). These UAS fit several “gaps” in available sensing technology: a small aircraft responds significantly to wind gusts, can be steered to regions of interest, and can be flown in dangerous environments without risking the pilot’s safety. A key focus of this dissertation is to improve the quality of airborne wind measurements provided by inexpensive UAS, specifically by leveraging mathematical models of the aircraft. The dissertation opens by presenting the motivation for this research and existing literature on the topics. Next, a detailed derivation of a suitable Flight Dynamic Model (FDM) for a fixed-wing aircraft in a turbulent wind field is presented. Special attention is paid to the theories for including aerodynamic effects of flying in non-uniform winds. In preparation for wind measurement experiments, a practical method for obtaining better quality FDMs is presented which combines theoretically based and data-driven approaches. A study into the wind-measurement error incurred solely by mathematical modeling is presented, focusing on simplified forms of the FDM which are common in aerospace engineering. Wind estimates which utilize our best available model are presented, accompanied by discussions of the model accuracy and additional wind measurement concerns. A method is developed to detect coherent structures from a circling UAS which is providing wind information, presumably via accurate model based estimation. The dissertation concludes by discussing these conclusions and directions for future research which have been identified during these pursuits.
Liebel, Matz. "Understanding molecular dynamics with coherent vibrational spectroscopy in the time-domain." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:e0289d80-f6e3-4e6f-817e-f8dd55d15bc4.
Повний текст джерелаNolan, Peter Joseph. "Experimental and Theoretical Developments in the Application of Lagrangian Coherent Structures to Geophysical Transport." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/88986.
Повний текст джерелаDoctor of Philosophy
How particles are moved by fluid flows, such as the oceanic currents and the atmospheric winds, is a problem with important implications for fields as diverse as: agriculture, aviation, human health, disaster response, and weather forecasting. Because these fluid flows tend to change over time, predicting how particles will be moved by these flows can often be challenging. Fortunately, mathematical tools exist which can reveal important geometric features in these flows. These geometric features can help us to visualize regions where particles are likely to come together or spread apart, as they are moved by the flow. In the past, these geometric features have been uncovered by using methods which look at the trajectories of particles in the flow. These methods are referred to as Lagrangian, in honor of the Italian mathematician Joseph-Louis Lagrange. Unfortunately, calculating the trajectories of particles can be a time consuming and computationally expensive process. Recently, new methods have been developed which look at how the speed of the flow changes in space. These new methods are referred to as Eulerian, in honor of the Swiss mathematician Leonhard Euler. These new Eulerian methods are faster and less expensive to calculate, while still revealing important geometric features within the flow. Because these Eulerian methods are so new, there is still much that we do not know about them and their connection to the older Lagrangian methods. This dissertation will fill in some of this gap and provide a mathematical bridge between these two methodologies. This dissertation is composed of three projects. These projects represent theoretical, numerical, and experimental advances in the understanding of these new Eulerian methods and their relationship to the older Lagrangian methods. The first project explores the deep mathematical relationship that exists between Eulerian and Lagrangian diagnostic tools. It mathematically proves that some of the new Eulerian diagnostics are the limit of Lagrangian diagnostics as the trajectory’s integration times is decreased to zero. Taking advantage of this discovery, a new Eulerian diagnostic is developed, called infinitesimal-time Lagrangian coherent structures. The second project develops a technique for estimating local Eulerian diagnostics using wind speed measures from a single fixed-wing unmanned aircraft system (UAS) flying in a circular path. Using computer simulations, we show that the Eulerian diagnostics as calculated from UAS measurements provide a reasonable estimate of the true local Eulerian diagnostics. Furthermore, we show that these Eulerian diagnostics can be used to estimate the local Lagrangian diagnostics. The third project applies these Eulerian diagnostics to real-world wind speed measurements. These results are then compared to Eulerian diagnostics that were calculated from a computer simulation to look for indications of Lagrangian diagnostics.
Clark, Thomas Henry. "Measurement of three-dimensional coherent fluid structure in high Reynolds number turbulent boundary layers." Thesis, University of Cambridge, 2012. https://www.repository.cam.ac.uk/handle/1810/243622.
Повний текст джерелаFarano, Mirko. "Using nonlinear optimization to understand coherent structures in turbulence and transition." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0047/document.
Повний текст джерелаThis thesis aims at unraveling the main mechanisms involved in transitional and turbulent flows. The central idea is that of using a nonlinear optimization technique to investigate the origin and role of coherent structures usually observed in these flows. This method has been used in three different contexts. First, a linearly stable laminar flow has been considered and the optimization has been used to compute the most amplified perturbations among all disturbances able to trigger transition to turbulence. Once turbulence is well established, a fully 3D nonlinear optimization maximizing the turbulent kinetic energy is used to study coherent structures populating turbulent shear flow as well as investigate the mechanisms responsible for the energy (optimally) growth and exchange. Then, a dynamical system approach is applied to fluid flow equations. The geometry of the state space is investigated by using transient growth theory to reveal the importance of the stable and unstable manifold. In the same framework, a nonlinear minimization algorithm is used to compute heteroclinic connections among invariant solutions of the Navier-Stokes equations
Martinez, Torres Cristina. "Structure and dynamics of single living cells : comparison of non intrusive coherent microscopicmethods and AFM indentation experiments." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10168/document.
Повний текст джерелаIn the first chapter of this thesis I discuss the importance of spatial and temporal scales in living systems, and I review the main components involved in the mechanical response of living cells. After this introductory chapter, the second one is dedicated to evaluating the mechanical response of single-cells with AFM, and in particular, its dynamical aspect. I present the analysis of force-indentation curves without any assumption on the linearity of the system, contrary to more typical analysis based on Sneddon’s or Hertz models. Then, I propose an alternative method to study the cell rheology based on the multi-frequency excitation of the cantilever by thermal noise. DPM is discussed on chapter three. I revisit the phase recovery method using the 2D wavelet transform, and I show how DPM can be used to characterize the temporal fluctuations and the morphology of different types of blood cells and adherent cells. Finally, chapter four is a conclusion chapter where I summarise our results by comparing healthy and pathological immature blood cells. For instance I show that, in comparison to healthy cells, leukaemic cells undergo morphological changes that are accompanied by a stiffer and more elastic behaviour. Altogether, our results indicate that this cell transformation involves the whole cytoskeleton and its coupling to the nucleus rather than simply the cell cortex
Horenkamp, Christian [Verfasser]. "Efficient detection of coherent structures in non-autonomous dynamical systems via transfer operator methods / Christian Horenkamp." Paderborn : Universitätsbibliothek, 2014. http://d-nb.info/1052264263/34.
Повний текст джерелаYang, Changhuei 1972. "Harmonic phase based low coherence interferometry : a method for studying the dynamics and structures of cells." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/28242.
Повний текст джерелаIncludes bibliographical references.
(cont.) Using this method, it is possible to determine the refractive index of a 1 mm thick sample with 7 significant figures. The unprecedented accuracy can potentially allow us to track subtle chemical changes in biological targets. Finally, we present the theoretical considerations of a method for suppressing turbidity in a scattering medium through the simultaneous use of phase conjugation and plane reflection. We show that the method is robust and warrants experimental investigation as a means for optical deep tissue imaging.
We report a novel optical imaging method based on the use of harmonically related light sources in a low coherence interferometer - harmonic phase-based low coherence interferometry (HPI). We demonstrate that, by processing the measured heterodyne phases appropriately, we can completely correct for motional jitter in the interferometer, which would otherwise make phase determination impossible. We apply the interferometer to study the phase velocity variation of ballistically propagating light traveling in a turbid medium and show that the phase velocity is dependent on the size of the scatterers. We next create a microscopy implementation of HPI. By exploiting the refractive index difference at the two wavelengths for contrast, the microscope is able to render details from unstained microscope sections based on their refractive index variations. We then exploit the property of low coherence interferometry to achieve depth resolution in our next adaptation of HPI - phase dispersion optical tomography. There, we demonstrate the ability to measure the reflection phase shift which can be used to determine properties of the reflecting materials. In addition, the technique can provide depth resolved dispersion information about a sample. We next apply HPI to tackle the challenge of tracking very small ([approx.] nm) arid very slow ([approx.] nm/s) cellular motions. Using a modified HPI system, we can study the cell membrane dynamics of a single cell without destroying it in the process. This system is about 2 orders of magnitude more sensitive than existing systems. In the final adaptation of the HPI, we demonstrate that HPI can be used to make absolute optical distance measurements with sub-nanometer accuracy.
by Changhuei Yang.
Ph.D.
Seghilani, Mohamed Seghir. "Highly coherent III-V-semiconductor laser emitting phase-, amplitude- and polarization-structured light for advanced sensing applications : Vortex, SPIN, Feedback Dynamics." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS207/document.
Повний текст джерелаThe goal of this PhD thesis is the study, design and the development of highly coherent III-V semiconductor laser sources based on multi-quantum wells (InGaAs/GaAs/AlGaAs) Vertical-External-Cavity-Surface-Emitting-Laser (VeCSEL), operating in the near infra-red (IR), and emitting high order Laguerre-Gauss (LG) and Hermite-Gauss (HG) modes. These modes, usually called ‘complex' or ‘structured' light, have a complex wavefronts, amplitudes and polarizations structures. We especially focus on lasers with modes carrying OAM, and also on sources with controlled photon's spin. These modes are of great interest for the development optical systems in several fields, such as telecommunications, optical tweezers, atom trapping and cooling, and sensing applications. We need to study the light eigenstates in high-finesse laser cavities, we describe these eigenstates with respect to the three axis of the light that define the photon state: longitudinal (frequency), transverse (spatial), and polarization. For each one of these axis, we study the physical ingredients governing mode formation, and develop the theoretical tools required for the calculation of the eigenmodes in non-conventional cavities.In a second step, as the mode selection in a laser involves light-matter interaction, we focus on dynamic study by writing the semi classical Maxwell-Bloch equations for our lasers. These equations allow us to study the role of temporal dynamics in laser mode selection, as well as the path the steady state. We use these theoretical models to explain some none /poorly understood questions, and which lead sometimes to erroneous interpretations in the scientific literature. We see in particular the question of the spontaneous selection of the wavefront handedness in vortex modes. We also address the development and the characterization of a III-V semiconductor based technology that enables us to efficiently select the wanted mode in the eigenbasis. We adopt an approach based on metamaterials integrated on the semiconductor gain structure (1/2- VCSEL) that play the role of a phase and amplitude mask. We use this technology to build a laser cavity that lifts the degeneracy and breaks the symmetry between vortex modes with opposite handedness. These two effects are of paramount importance when one wants to select a vortex mode with a well-defined charge and handedness. In order to control the polarization modes, we study the polarization properties of the optical cavity and the quantum-well based gain medium: the birefringence the dichroism, and the spin-flip time in the quantum wells. We make use of these elements to generate the wanted polarization states: stable linear, and circular carrying an angular momentum controlled via the pump spin. In the end, we present the design and building of a feedback laser sensor (self-mixing) for linear and rotational velocimetry, using a laser source emitting a vortex beam. This sensor shows an example of a measurement inaccessible using conventional laser sources. It takes advantage of the orbital angular momentum of the vortex beam to measure both translational and rotational velocities using the Doppler effect. We end this part by presenting other possible sensor designs for particle sizing, using other exotic modes generated in this work
Teramura, Toshiki. "Spatially localized self-sustaining mechanism induced by inhomogeneity in turbulence." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215294.
Повний текст джерелаFujiwara, Takashige. "Structure and Excited-State Dynamics of 9,9′-Bianthryl and its van der Waals Clusters Studied by Rotational Coherence Spectroscopy." 京都大学 (Kyoto University), 2000. http://hdl.handle.net/2433/151661.
Повний текст джерелаThouvenin, Olivier. "Optical 3D imaging of subcellular dynamics in biological cultures and tissues : applications to ophthalmology and neuroscience." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC169/document.
Повний текст джерелаThis PhD project aims to explore the relationship that might exist between the dynamic motility and mechanical behavior of different biological systems and their biochemical activity. In particular,we were interested in detecting the electromechanical coupling that may happen in active neurons, and may assist in the propagation of the action potential. With this goal in mind, we have developed two highly sensitive optical microscopes that combine one modality that detects sub-wavelength axial displacements using optical phase imaging and another modality that uses a fluorescence path. Therefore, these multimodal microscopes can combine a motility, a mechanical,a structural and a biochemical contrast at the same time. One of this system is based ona multimodal combination of full-field optical coherence tomography (FF-OCT) and allows the observation of such contrast inside thick and scattering biological tissues. The other setup provides a higher displacement sensitivity, but is limited to measurements in cell cultures. In this manuscript, we mainly discuss the development of both systems and describe the various contrastst hey can reveal. Finally, we have largely used our systems to investigate diverse functions of the eye and to look for electromechanical waves in cell cultures. The thorough description of both biological applications is also provided in the manuscript
MARINI, FRANCESCO. "Wave induced hydro and morpho-dynamics around a single slender pile: experimental and numerical analysis." Doctoral thesis, Università Politecnica delle Marche, 2020. http://hdl.handle.net/11566/274622.
Повний текст джерелаDuring the last years, the presence of piled structures, such as offshore wind farms or oil platforms, in the marine environment is becoming more important. For this reason, it gains relevance the correct analysis of possible criticisms and uncertainties in the design process. The aim of this thesis is the study of both the hydrodynamics and the morpho-dynamics induced by regular and random waves over a single slender pile by means of laboratory and numerical modelling. Therefore, the objective of the present thesis is to contribute to a better understanding of such physical processes. In particular, it aims to provide some tools that can be useful in the design process, in order to avoid a wrong estimation of the most important parameters and, thus, to ensure a proper design of the piled marine structure and its facilities. Particular attention is paid on the evaluation of the total force due to wave action, on the scour at the base of the pile and on the run-up over its surface. A rigid bed model has been realised to evaluate the best approach for the estimation of the total force over the pile due to nonlinear waves. An alternative method to the classical Morison (1950)'s approach has been proposed for the computation of the total force from the velocity and acceleration of the water particles from a measured water surface elevation time series. Such method consists in a Fourier spectral decomposition of the input free water surface signal; the contribution of each component, computed according to the Airy theory, is summed to obtain the total horizontal and vertical velocity along the vertical profile. The results showed that this approach allowed to give a very good estimate of the total force both in terms of maximum value and of the phase in which it occurs. On the contrary, the application of the linear theory for the calculation of the velocity to be applied in the force calculation (classical Morison approach used in the design process) leads to an underestimation of the peak value and to a wrong representation of the shape of the force. Another primary parameter in the stability of a structure in the marine environment is the scour at the base of the monopile. This experimental campaign is performed by means of a mobile bed model in which a vertical cylinder is placed over a sandy seabed and it is attacked by both regular and random nonlinear waves. The results for regular waves are quite in agreement with the earlier work of Sumer et al. (1992). However, the results of this study reveal that the scour process due to nonlinear regular waves starts for hydrodynamic conditions characterized by a lower intensity Keulegan-Carpenter parameter KC=4) in comparison with those reported in the literature for linear waves (KC=6). Different formulas are proposed for its estimation depending on dimensionless parameters (KC, Ur). For random waves, the approach proposed by Ong et al. (2013) for scour evaluation has been modified. This method depends on the cumulative distribution function of the dimensionless crest heights but, because of its complexity, it has been simplified in order to became suitable for design purposes without affecting the quality of the results. To better understand the process of formation, growth and detachment of vortices, PTV measurements are carried out and the results are integrated with those from pressure sensors and from the mobile bed model for the characterization of the whole process of vortex formation and scour generation. The results showed that the wave phases and positions in which the maximum values of the pressure gradients occur, correspond to those in which the detachment of vortices is observed. From the interpretation of the contour maps of the vorticity and of the OW parameter it is possible to explain the scour patterns obtained in the mobile bed campaign. Furthermore, a numerical model has been realised with the tool OpenFOAM that permitted to contribute to the comprehension of the complex 3D physical phenomenon induced by the wave-structure interaction. A new wave generation boundary condition for the generation of a measured water surface elevation time series has been added to the numerical code. The corresponding velocity field in this BC has been computed with the Fourier decomposition method mentioned above. The nonlinear waves of the rigid bed experimental campaign are here simulated for the better comprehension of the vortex formation process and for the estimation of wave run-up which is very important for the design of the access facility of the marine structures. Excellent results are obtained in comparison with experimental data of force, pressure, velocity and water elevation. The analysis of the maximum values of run-up is performed and the results are compared with some formula available in the literature. An adaptation of the equation of Hallermeier (1976) that compute the run-up depending on the crest height, is proposed and the results, obtained with a significant number of samples, are very good. Finally, the visualization of the three-dimensional vortical structures by means of the Q-criterion has been performed. The numerical results showed that, in some instances, a vortex generated during the first half of the period can remain in the area of influence of the pile. After the reversal of the flow, it changes the direction according to the stream until it is finally removed on the opposite side of the pile with respect to where it was generated. The results are in agreement with those of the PTV campaign: both the phase, size and position of vortices are well represented. The achievements obtained with the numerical model are able to improve the understanding of the complex physical processes by linking the different results, such as the pressure gradients, vortical structures and the associated scour patterns.
Ruppert-Felsot, Jori Elan Swinney H. L. "Coherent structures and two-dimensionalization in rotating turbulent flow." 2005. http://repositories.lib.utexas.edu/bitstream/handle/2152/1804/ruppertfelsotj35992.pdf.
Повний текст джерелаRuppert-Felsot, Jori Elan. "Coherent structures and two-dimensionalization in rotating turbulent flow." Thesis, 2005. http://hdl.handle.net/2152/1804.
Повний текст джерелаLünsmann, Benedict Johannes. "Detection of Coherent Structures in Two-Dimensional Oceanic Flows: On Improvements of the Transfer Operator Approach and Convexity as a Condition of Coherence." 2019. https://tud.qucosa.de/id/qucosa%3A37731.
Повний текст джерелаEs ist bekannt, dass quasi-zweidimensionale turbulente Strömungen, wie etwa Strömungen an der Meeresoberfläche oder großskalige Atmosphärenbewegungen, kohärente Strukturen ausbilden, kompakte Volumina, welche einer Mischung mit dem umgebenden Material für endliche Zeit widerstehen, obwohl die Strömung als solche turbulent ist. Diese Strukturen haben einen signifikanten Einfluss auf den Transport von Fluidelementen. Der Transport von passiven skalaren Größen, wie etwa Wärme, Feuchtigkeit, Salzgehalt, Nährstoffgehalt, jegliche Konzentration che- mischer Stoffe und sogar Algendichte hat wiederum einen Effekt auf unzählige geophysikalische Phänomene. Um diese Phänomene im Detail zu verstehen, sind zuverlässige Methoden für die Detektion von kohärenten Strukturen und die Identifikation ihrer Grenzen notwendig. In der vorliegenden Arbeit präsentieren wir zwei Beiträge zur Lösung dieses Problems. Als erstes präsentieren wir Verbesserungen der Transferoperatormethode. Diese etablierte Methode zur Identifikation von fast-invarianten und kohärenten Mengen approximiert die Transporteigenschaften eines Flusses mithilfe eines linearen Transferoperators, mit dem Ziel, das betrachtete Gebiet in Bereiche zu unterteilen, welche den Materialaustausch zwischen den Bereichen minimieren. Die Verbesserungen beinhalten die Einführung von mischenden Randbedingungen in stationären und nicht-stationären Flüssen. Dabei wird der Transferoperator so modifiziert, dass Filamente, welche die kohärente Struktur umgeben, gekoppelt werden, was zur Folge hat, dass effektiv nur zwei nicht kommunizierende Strukturen übrig bleiben: die kohärente Struktur und das sie umgebende Volumen. Dies führt zu einer signifikant erhöhten Stabilität der Methode ohne auf die sonst üblichen aber fehleranfälligen clustering-Techniken zurückgreifen zu müssen. Des Weiteren diskutieren wir die Identifikation von zeitlich konsistenten Regionen erhöhter Kohärenz. Anstatt von kohärenten Strukturen als bewegliche nicht filamentierende Massen zu sprechen, beschreibt dieses Konzept kohärente Strukturen als konsistente sich bewegende Regionen reduzierten Mischverhaltens deren beteiligte Masse zeitlich veränderlich ist. Dies erlaubt die Entkopplung der Kohärenzzeitskala vom betrachteten Zeitfenster. Im Anschluss verwenden wir beide Modifikationen, um die Transporteigenschaften von acht ausgewählten Ostseewirbeln zu untersuchen. Als zweiten Beitrag stellen wir den MSCS-Algorithmus vor, eine neue Methode zur Identifikation von kohärenten Strukturen, welche einzig und allein auf dem Prinzip von Konvexität basiert. Versteht man kohärente Strukturen als nicht filamentierende Massen, ist persistente Konvexität eine hinreichende Bedingung für Kohärenz. Konvexität wurde bisher noch nie als Grundlage für Kohärenz untersucht, obwohl sie aus praktischen Gründen in einigen Methoden bereits als einschränkende Bedingung verwendet wird. Die Methode identifiziert die größte Struktur innerhalb eines gegebenen Volumens, welches während eines gegebenen Zeitraums stern-konvex bezüglich einer gegebenen Referenztrajektor bleibt. Alle studierten Testszenarien zeigen, dass der Ansatz gute und zuverlässige Ergebnisse liefert. Diese Ergebnisse hängen darüber hinaus direkt von den Eingangsparametern ab, was die Interpretation der Ergebnisse stark erleichtert und zusätzlich die Untersuchung von Filamentbildung erlaubt. Die neue Methode wird verwendet um den kohärenten Transport in den bereits untersuchten Ostseewirbeln zu reevaluieren.:1 Introduction 2 Theoretical Background 2.1 Methods 2.1.1 Okubo-Weiss criterion 2.1.2 Finite-Time Lyapunov Exponents 2.1.3 Lagrangian Descriptors and Lagrangian averaged vorticity deviation 2.2 Models 2.2.1 Euler equation 2.2.2 Stationary Gaussian Blob Model 2.2.3 Periodically Perturbed Gaussian Blob Model 2.2.4 Bickley-Jet 3 Transfer Operator Approach I: State of the Art 3.1 Frobenius-Perron Operator 3.2 Markov-Chains 3.3 Laplacian matrices 3.4 Finding Almost-Invariant Sets 3.5 Finding Coherent Sets 3.5.1 Coherent pairs as tuples 3.5.2 Coherent pairs as triples 3.6 Spectral Clustering 3.7 Critique and Discussion 4 Transfer Operator Approach II: Mixing Boundary Conditions in Stationary Flows 4.1 Overview 4.2 Estimation of Transfer Probability Matrices P 4.3 Mixing Boundary Conditions 4.4 Thresholding 4.5 Results 4.5.1 Robustness with respect to parameters 4.5.2 Comparison and alternatives 4.5.3 Handling of false positives 4.5.4 Periodically perturbed flow 4.6 Closing Remark 5 Transfer operator approach III: Analysis of Oceanic Transport 5.1 Mixing Boundary Conditions: Time-Dependent Flows 5.1.1 Method 5.1.2 Results 5.2 Temporal consistency 5.2.1 Method 5.2.2 Results 5.3 Treatment of Coastal Effects 5.4 Application to Baltic velocity fields 5.4.1 Method 5.4.2 Results 5.5 Closing Remark 6 Prototypes of Coherent Sets: Star-Convex Structures 6.1 Mathematical Considerations 6.2 MSCS-Algorithm 6.3 Extracting star-convex sub-volumes 6.4 Results 6.4.1 Stationary Gaussian blob model 6.4.2 Bickley-Jet 6.4.3 Two dimensional inviscid flow 6.4.4 Real data sets 6.5 Closing Remark 7 Conclusion and Outlook
El, aouni Anass. "Lagrangian coherent structures and physical processes of coastal upwelling." Thesis, 2019. http://www.theses.fr/2019BORD0146.
Повний текст джерелаStudying physical processes of an upwelling system is essential to understand its present variability and its past and future changes. This thesis presents an interdisciplinary study of the coastal upwelling system from different satellite acquired data, with the main focus placed on the North West African (NWA) upwelling system. This interdisciplinary study covers (1) the problem of the automatic identification and extraction of the upwelling phenomenon from biological and physical satellite observations. (2) A statistical study of the spatio-temporal variation of the NWA upwelling throughout its extension and different upwelling indices. (3) A Study of the nonlinear relationships between the surface mixing and biological activity in the upwelling regions. (4) Lagrangian studies of coherent eddies; their physical properties and automatic identification. (5) The study of transport made by Lagrangian eddies off the NWA Upwelling and their impact on the open ocean. [...]
"Experimental investigation of energy cascades, coherent structures and scalar mixing in convective thermal turbulence." Thesis, 2008. http://library.cuhk.edu.hk/record=b6074625.
Повний текст джерелаIn the second part of the thesis, the simultaneous visualization of the temperature and velocity fields was used to study the properties of thermal plumes. Our visualization reveals the process of the morphological evolution between sheetlike and mushroomlike plumes, which were also quantified by the height dependence of plume numbers and of vorticity fluctuations. A direct connection between the heat transport and coherent structures, i.e. thermal plumes, was established, which shows that it is plume number that primarily determines the Nu-Ra scaling relation. Individual plumes were extracted and their statistical and geometric properties were studied. It is found that the log-normal distribution is universal for thermal plumes and the log-normal statistics may be used to model them. In addition, both our quantitative characteristic and direct 3D spatial visualizations indicate that the previously-believed sheetlike plumes should be reconsidered to be only one-dimensional structures.
In the third part of the thesis, the planar laser-induced fluorescence technique was induced to study the 2D passive scalar mixing in high-Schmidt-number buoyancy-driven turbulence. The passive scalar mixing evolution was studied and various geometric properties, such as shape complexity, fractal dimension and local curvature, were used to characterize the isoconcentration contours of the 2D passive scalar fields. It is found that when the flow gets more turbulent the shape of passive scalar packets becomes closer to a circular shape and the passive scalar mixing becomes more isotropic, indicating the increased mixing and stirring of the turbulent flow.
The objective of this thesis is to address the following three key issues in turbulent thermal convection, i.e. turbulent fluctuations in small scales, coherent structures and passive scalar mixing in buoyancy-driven turbulence.
Zhou, Quan = 對流熱湍流中能量級串, 相干結構和標量場混合的实验研究 / 周全.
Adviser: Ke-Qing Xia.
Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3576.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2008.
Includes bibliographical references (leaves 103-117).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstracts in English and Chinese.
School code: 1307.
Zhou, Quan = Dui liu re tuan liu zhong neng liang ji chuan, xiang gan jie gou he biao liang chang hun he de shi yan yan jiu / Zhou Quan.
Ahmari, Habib. "SIZE, DYNAMICS AND CONSEQUENCES OF LARGE-SCALE HORIZONTAL COHERENT STRUCTURES IN OPEN-CHANNEL FLOWS: AN EXPERIMENTAL STUDY." Thesis, 2010. http://hdl.handle.net/1974/8297.
Повний текст джерелаThesis (Ph.D, Civil Engineering) -- Queen's University, 2010-03-09 10:20:53.596
Eickemeyer, Felix [Verfasser]. "Ultrafast dynamics of coherent intersubband polarizations in quantum wells and quantum cascade laser structures / von Felix Eickemeyer." 2002. http://d-nb.info/965430227/34.
Повний текст джерела