Дисертації: "Traps dynamics"

1

Lunney, Matthew David Norwood. "Dynamics of ions in radiofrequency quadrupole traps." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65463.

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2

Guizar-Mateos, Isai. "Financial Development, the Dynamics of Technology Choices, and Poverty Traps." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374159141.

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3

Ziesel, Frank [Verfasser]. "Quantum State Manipulation and Dynamics in Micro Ion Traps / Frank Ziesel." Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2013. http://d-nb.info/1032947470/34.

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4

Klotz, Alexander. "Statics and dynamics of DNA in a network of nanofluidic entropic traps." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104815.

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A nanofluidic slit embedded with a lattice of square pits was used to entropically trap polymers. DNA in the system was confined to two dimensions and underwent self-assembly into discrete conformational states based on the number of occupied pits. The molecules diffused by undergoing transitions to higher or lower pit-occupancy states and relaxing to their equilibrium state. A statistical mechanical model was used to predict the mean occupancy state as a function of various geometric parameters. Experiments confirm many of the predictions of the model. Regions of parameter space over which a single state dominates were observed, indicating that entropic trapping can be used to create stable self-assembled single polymer conformations. Measurements of diffusion showed it to be geometry dependent, allowing a fine-tuning of diffusivity. The diffusion showed non-monotonic behaviour: local minima corresponding the stable equilibrium states were observed. This demonstrates that the diffusion can be fine-tuned to a local resonance using entropic trapping. The results show that polymers can self-assemble into entropically stable structures, with implications for nanotechnology and biophysics.
Nous avons piégé des polymères avec un trellis de fosses nanofluidiques de forme carrée. Nous avons confiné l'ADN en deux dimensions. Il s'est auto-assemblé en états discrets et qui determine du nombre du fosses. Les molecules one sauté et sont tombe es dans un nouvel état, et diffusaient. Nous avons utilisé un modèle mécanique statistique pour une prédire le nombre moyen de fosses. Les expériences confirment le modèle. Nous avons vu des plateaux avec un unique état dominant. Cela signifie que nous pouvons utiliser le piège entropique pour la nanotechnologie : car les structures sont stables. Nous avons mesuré la diffusion. Elle dépend de la géométrie et est non monotonique. Elle a un minimum local vers la region des plateaux. Nous pouvons utiliser le piège entropique pour contrôler la diffusion. Les résultats sont utiles pour la nanotechnologie et biophysique.

5

Klumpp, Andrea [Verfasser], and Peter [Akademischer Betreuer] Schmelcher. "Nonequilibrium dynamics of Coulomb crystals in double well traps / Andrea Klumpp ; Betreuer: Peter Schmelcher." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2018. http://d-nb.info/1170872859/34.

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6

Chatterjee, Budhaditya [Verfasser], and Lorenz S. [Akademischer Betreuer] Cederbaum. "Tunneling Dynamics of Few-Boson Systems in Double-Well Traps / Budhaditya Chatterjee ; Betreuer: Lorenz S. Cederbaum." Heidelberg : Universitätsbibliothek Heidelberg, 2011. http://d-nb.info/1179783948/34.

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7

Köberle, Patrick [Verfasser]. "Ground-state structures and dynamics of dipolar Bose-Einstein condensates in single and multi-layered traps / Patrick Köberle." München : Verlag Dr. Hut, 2011. http://d-nb.info/1016531664/34.

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8

Halkyard, Paul Lee. "Dynamics in cold atomic gases : resonant behaviour of the quantum delta-kicked accelerator and Bose-Einstein condensates in ring traps." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/529/.

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In this thesis, the dynamics of cold, trapped atomic gases are investigated, and the prospects for exploiting their nonlinear dynamics for inertial sensing are discussed. In the first part, the resonant and antiresonant dynamics of the atom-optical quantum delta-kicked accelerator with an initial symmetric momentum distribution are considered. The system is modelled as an ideal, non-interacting atomic gas, with a temperature-dependence governed by the width of the initial momentum distribution. The existence of resonant and antiresonant behaviour is established, and analytic expressions describing the dynamics of momentum moments of the time-evolved momentum distribution are derived. In particular, the momentum moment dynamics in both the resonant and antiresonant regimes depend strongly on the width of the initial momentum distribution. The resonant dynamics of all even-ordered momentum moments are shown to exhibit a power-law growth with an exponent given by the order of the moment in the zero-temperature regime, whereas for a broad, thermal initial momentum distribution the exponent is reduced by one. The cross-over in the intermediate regime is also examined, and a characteristic time is determined up to which the system exhibits dynamics associated with the zero-temperature regime. A similar analysis is made for the temperature-dependence of the antiresonant dynamics. This general behaviour is demonstrated explicitly by considering a Maxwell-Boltzmann and uniform momentum distribution, allowing exact expressions describing the dynamics of the second- and fourth-order momentum moments, and momentum cumulants, to be obtained. The relevance of these results to the potential of using this system in accurate determinations of the local gravitational acceleration is discussed. In the second part, the dynamics of one- and two-component Bose-Einstein Condensates prepared in a counter-rotating superposition of flows in a quasi-1D toroidal trap are studied. Particular attention is paid to the dynamical stability of the initial state in the presence of atom-atom interactions, included via a mean-field description within the Gross-Pitaevskii equation. A broad regime of dynamical stability using a two-component BEC is identified, in which a typical implementation using Rb-87 is predicted to lie. A proof-of-principle Sagnac atom-interferometer using a two-component Rb-87 BEC is then presented, and the accumulation of the Sagnac phase is shown to be possible via relative population measurement or, alternatively, through the continuous monitoring the precession of atomic density fringes. In contrast to conventional Sagnac interferometers, the accumulation of the Sagnac phase is independent of the enclosed area of the interferometer. The prospects of using this system for high-precision determinations of rotation is discussed.

9

Coop, Simon. "Nonlinear behaviour of ultracold atoms in optical dipole traps : large atomic light shifts, a quantum phase transition, and interaction-dependent dynamics." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/663161.

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This thesis reports on theory and results from two experiments related to nonlinear behaviour in ensembles of optically-trapped ultracold atoms. The first experiment, performed at ICFO in Barcelona, regards the prediction and measurement of strong ac Stark shifts (light shifts). We present a numerical method based on Floquet's theorem for calculating light shifts to all orders with fewer approximations than the usual calculation based on second-order perturbation theory. The method is experimentally validated by performing absorption spectroscopy of a optically-trapped cloud of cold 87Rb atoms in three scenarios. 1) The atoms are trapped in a singly-polarised monochromatic dipole trap with a wavelength detuned aprox 30nm from the nearest atomic transition. 2) A bichromatic two-polarisation trap, where one wavelength is much closer to atomic transitions (aprox 0:01nm detuning), and finally 3) Another monochromatic trap but with the wavelength variable and scanned close to atomic transitions, again with aprox 0:01nm detuning but three times the intensity of the near-resonant light in the previous experiment, producing nonlinear light shifts of the D2 transition upto aprox 1 GHz. We discuss the potential application of the method to the accuratemeasurement of electric dipole transition matrix elements. The method is extendedto calculate atomic energy level shifts in the presence of light and staticmagnetic fields. The second experiment was performed at LENS in Florence, and involves 39K atoms with tunable interactions cooled into the ground- and first-excited state of a two-mode optical potential. We derive a diferential equation to describe behaviour of a two-mode quantum system with tunable interactions, and then solve it to model behaviour of the system in the three distinct regimes of attractive, zero, and repulsive interatomic interactions. With attractive interactions the system is shown to exhibit a quantum phase transition, and with repulsive interactions is shown to exhibit nonlinear dynamics, including behaviour analogous to a superconducting Josephson junction. As background material the thesis presents a summary of standard laser cooling and trapping echniques, namely Doppler cooling, o+ o- polarisation gradient cooling, magneto-optical trapping, and optical trapping. Optical traps are discussed in detail. We discuss relevant basic physics, derive and analyse a technique for using light shifts to characterise an optical trap, discuss optical Bose-Einstein condensation and control of light intensity to reduce noise-induced heating. Also described is a theoretical proposal for optical evaporation with a constant-depth trap.
Esta tesis describe la investigación teórica y los resultados de dos experimentos relacionados con el comportamiento no lineal en un conjuntos de áatomos ultrafríos atrapados ópticamente. En el primer experimento, realizado en ICFO en Barcelona, se presenta la predicción y unos resultados de fuertes cambios de ac Stark (light shifts). Se explica un método numérico basado en el teorema de Floquet para calcular light shifts a todos órdenes con menos aproximaciones que el método habitualmente usado basado en teoría de perturbaciones de segundo orden. El método se valida experimentalmente mediante la realización de espectroscopía de absorción en una nube de átomos de 87Rb ópticamente atrapados en tres escenarios distintos. En el primero, los átomos están atrapados en una trampa de dipolo monocromática de polarización única con una longitud de onda desintonizada 30nm a la transición atómica más cercana. En el segundo se emplea una trampa bicromática de dos polarizaciones, donde una longitud de onda está mucho más cerca de las transiciones atámicas (0.01nm fuera de resonancia). En el tercer y ultimo escenario, se usa una trampa monocromática con la longitud de onda variable y escaneado cerca de transiciones atómicas, nuevamente con 0.01nm desintonizada pero tres veces más intensa que la luz casi resonante del experimento anterior, produciendo light shifts no lineales de la transición D2 hasta 1 GHz. Se discute la aplicabilidad del método para la medición precisa de los elementos de la matriz de transición dipolar eléctrica. Por último, el método se extiende permitiendo calcular los cambios de niveles de energía atómica en presencia de luz y campos magnéticos estáticos. El segundo experimento que se describe en esta tesis se realizó en LENS, en Florencia, e involucra átomos de 39K con interacciones sintonizables en átomos fríos ocupando al estado fundamental y el primer estado excitado de un potencial óptico de dos modos. Se deriva una ecuación diferencial para describir el comportamiento de un sistema cuántico de dos modos con nteracciones sintonizables. Esta se resuelve para modelar el comportamiento del sistema en tres regímenes distintos de interacciones inter-atómicas: atractivas, nulas y repulsivas. En el caso de interacciones atractivas se muestra que el sistema exhibe una transición de fase cuántica. En presencia de interacciones repulsivas el sistema muestra dinámica no lineal, incluyendo un comportamiento análogo a una unión superconductora de Josephson. Como material de referencia, la tesis presenta un resumen de las técnicas estándar de enfriamiento y atrapamiento láser, concretamente enfriamiento Doppler, enfriamiento por gradiente de polarización, atrapamiento magneto-óptico y atrapamiento óptico. Las trampas ópticas se revisan en detalle. Discutimos la física básica relevante, derivamos y analizamos una técnica para usar los light shift para caracterizar una trampa óptica. Analizamos la condensación óptica de Bose-Einstein y el control de la intensidad de la luz para reducir el calentamiento inducido por el ruido. También se presenta una propuesta teórica para la evaporación óptica con una trampa de profundidad constante.

10

Lazem, Shaimaa. "Analysis of the Relationships between Changes in Distributed System Behavior and Group Dynamics." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/26732.

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The rapid evolution of portable devices and social media has enabled pervasive forms of distributed cooperation. A group could perform a task using a heterogeneous set of the devices (desktop, mobile), connections (wireless, wired, 3G) and software clients. We call this form of systems Distributed Dynamic Cooperative Environments (DDCEs). Content in DDCEs is created and shared by the users. The content could be static (e.g., video or audio), dynamic (e.g.,wikis), and/or Objects with behavior. Objects with behavior are programmed objects that take advantage of the available computational services (e.g., cloud-based services). Providing a desired Quality of Experience (QoE) in DDCEs is a challenge for cooperative systems designers. DDCEs are expected to provide groups with the utmost flexibility in conducting their cooperative activities. More flexibility at the user side means less control and predictability of the groupsâ behavior at the system side. Due to the lack of Quality of Service (QoS) guarantees in DDCEs, groups may experience changes in the system behavior that are usually manifested as delays and inconsistencies in the shared state. We question the extent to which cooperation among group members is sensitive to system changes in DDCEs. We argue that a QoE definition for groups should account for cooperation emergence and sustainability. An experiment was conducted, where fifteen groups performed a loosely-coupled task that simulates social traps in a 3D virtual world. The groups were exposed to two forms of system delays. Exo-content delays are exogenous to the provided content (e.g., network delay). Endo-content delays are endogenous to the provided content (e.g., delay in processing time for Objects with behavior). Groups' performance in the experiment and their verbal communication have been recorded and analyzed. The results demonstrate the nonlinearity of groups' behavior when dealing with endo-content delays. System interventions are needed to maintain QoE even though that may increase the cost or the required resources. Systems are designed to be used rather than understood by users. When the system behavior changes, designers have two choices. The first is to expect the users to understand the system behavior and adjust their interaction accordingly. That did not happen in our experiment. Understanding the system behavior informed groups' behavior. It partially influenced how the groups succeeded or failed in accomplishing its goal. The second choice is to understand the semantics of the application and provide guarantees based on these semantics. Based on our results, we introduce the following design guidelines for QoE provision in DDCEs. â ¢If possible the system should keep track of information about group goals and add guarding constraints to protect these goals. â ¢QoE guarantees should be provided based on the semantics of the user-generated content that constitutes the group activity. â ¢Users should be given the option to define the content that is sensitive to system changes (e.g., Objects with behavior that are sensitive to delays or require intensive computations) to avoid the negative impacts of endo-content delays. â ¢Users should define the Objects with behavior that contribute to the shared state in order for the system to maintain the consistency of the shared state. â ¢Endo-content delays were proven to have significantly negative impacts on the groups in our experiment compared to exo-content delays. We argue that system designers, if they have the choice, should trade processing time needed for Objects with behavior for exo-content delay.
Ph. D.

11

Neugebauer, Thomas [Verfasser], Thomas [Akademischer Betreuer] Drewello, Thomas [Gutachter] Drewello, and Jörg [Gutachter] Libuda. "Dynamics of the Collision-Induced Dissociation Process in Quadrupole Ion Traps and its Application / Thomas Neugebauer ; Gutachter: Thomas Drewello, Jörg Libuda ; Betreuer: Thomas Drewello." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2019. http://d-nb.info/1201886899/34.

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12

Adjaye, John. "Influence of source/drain residual implant lattice damage traps on silicon carbide metal semiconductor field effect transistor drain I-V characteristics." Diss., Mississippi State : Mississippi State University, 2007. http://sun.library.msstate.edu/ETD-db/theses/available/etd-09242007-081525.

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13

Lopez, garcia Andres Jenaro. "Contribution à l'étude des propriétés piézoélectriques de nanofils de ZnO et de nanocomposites associés en vue d’une application à la conversion d’énergie mécanique à électrique." Thesis, Université Grenoble Alpes, 2022. http://www.theses.fr/2022GRALT043.

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Avec le développement croissant de réseaux sans fil de capteurs de faible puissance pour ce que l’on appelle l’Internet des objets, il est nécessaire de trouver des moyens efficaces d’assurer l’autonomie énergétique des nœuds de détection. Parmi les différentes solutions de récupération d’énergie, la conversion en énergie électrique de l’abondante énergie mécanique présente dans l’environnement est très prometteuse. Dans ce domaine de recherche émergent, les nanofils (NFs) de ZnO ont été fortement étudiés au cours de ces deux dernières décennies, à la fois en tant que tels, et intégrés dans des nanocomposites. À l’échelle nanométrique, ils présentent des propriétés électromécaniques meilleures que le matériau massif, ainsi qu’une intégration facile sur des substrats rigides ou flexibles. Néanmoins, des divergences intrigantes entre les résultats expérimentaux et les simulations numériques disponibles au début de cette thèse ont mis en évidence la nécessité d’une meilleure compréhension du fonctionnement piézoélectrique des composites à base de NF, en particulier pour ce qui concerne deux aspects importants qui avaient été peu traités jusqu’alors: le couplage entre les propriétés piézoélectriques et semi-conductrices dans les simulations numériques et la dépendance des propriétés électromécaniques avec la méthode de croissance des NFs de ZnO ou avec l’influence de l’environnement des NFs dans les expériences.Du point de vue théorique, cette thèse de doctorat étudie le couplage des propriétés piézoélectriques et semi-conductrices des NFs de ZnO et de leur nanocomposites et fournit des lignes directrices d’optimisation pour les applications de transduction électromécanique. Cette étude prend en compte l’influence du niveau de dopage, de la densité de porteurs libres, des pièges d’interface et des paramètres géométriques sur les paramètres électromécaniques. Des simulations numériques de nanocomposites à base de NF de ZnO sous compression mécanique ont été effectuées à l’aide de la méthode des éléments finis (FEM). Expérimentalement, plusieurs modes de microscopie à force atomique (AFM), tels que la microscopie à force piézoélectrique (PFM), la microscopie à force de sonde Kelvin (KPFM) et la microscopie à force atomique conductrice (C-AFM) ont été utilisés, afin de sonder localement les paramètres électriques et électromécaniques qui jouent un rôle clé dans l’efficacité de la réponse piézoélectrique des NFs de ZnO. Nos résultats ont montré que le niveau de dopage, les porteurs libres et les pièges d'interface, ainsi que la dynamique des pièges, doivent être pris en compte pour expliquer l’amplitude et l’asymétrie potentielle de la réponse électromécanique ou l’influence que la géométrie a sur elle. Ils montrent que les propriétés semi-conductrices doivent être prises en compte pour l’analyse des résultats expérimentaux et la conception correcte de dispositifs électromécaniques autonomes basés sur des NFs de ZnO et leurs nanocomposites
With the increasing development of wireless networks of low-power sensors for the so-called internet-of-things, there is a need for efficient ways to ensure the energetic autonomy of sensing nodes. Among the various energy harvesting solutions, converting the abundant mechanical energy present in the environment into electrical energy is very promising. In this emerging field of research, ZnO nanowires (NWs) have been strongly studied during these last two decades, both as such, and integrated into nanocomposite materials. At the nanoscale, they feature improved electromechanical properties compared to bulk, as well as easy integration and manufacturing, on both rigid and flexibles substrates. However, some intriguing discrepancies between the experimental and simulation results available at the beginning of this PhD highlighted the need for a better understanding of the piezoelectric operation of NW-based composites, especially for what concerns two important aspects which had been poorly addressed so far: the coupling between piezoelectric and semi-conducting properties in simulations, and the dependence of electromechanical properties with ZnO NW growth method or with NW surrounding environment in experiments.From the theoretical point of view, this Ph.D. thesis studies the coupling of piezoelectric and semiconducting properties in ZnO NWs and related nanocomposites and provides optimization guidelines for mechanical to electrical transducing applications. It investigates the influence of doping level, free carrier density, interface traps and geometrical parameters on electromechanical parameters. Simulations of ZnO NW-based nanocomposites under mechanical compression were performed using the Finite Element Method (FEM). Experimentally, several atomic force microscopy (AFM) modes, such as piezoelectric force microscopy (PFM), Kelvin probe force microscopy (KPFM), and conducting atomic force microscopy (C-AFM) were used, in order to probe locally electrical and electromechanical parameters which play a key role in the efficiency of the piezoelectric response of ZnO NWs. Our results showed that doping level, free carriers and surface traps, as well as traps dynamics, must be considered in order to explain the amplitude and the potential asymmetry of the electromechanical response, or the influence that geometry has on it. They demonstrate that semiconducting properties should be taken into account for the analysis of experimental results and for the correct design of electromechanical self-powered devices based on ZnO NWs and nanocomposites

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Heikal, Ahmed Abdou Zewail Ahmed H. Zewail Ahmed H. "Ultrafast molecular dynamics in complexed trans-stilbene /." Diss., Pasadena, Calif. : California Institute of Technology, 1996. http://resolver.caltech.edu/CaltechETD:etd-12192007-150129.

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15

Zhang, Yuanzhe. "Pd/azaborine-biaryl phosphine complexes: reaction development, mechanistic analysis, and investigations into metal-ligand coordination dynamics." Thesis, Boston College, 2021. http://hdl.handle.net/2345/bc-ir:109152.

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Thesis advisor: Shih-Yuan Liu
Described herein are three research projects that focused on 1) the catalytic activities of Pd/azaborine-derived biary phosphine (Senphos) complexes in 1,3-enyne difunctionalization reactions and 2) the coordination behaviors of these Pd/Senphos complexes. In the first chapter, expansion of the substrate scope and mechanistic studies of the reported Pd/Senphos catalyzed site-, regio- and trans-selective hydroboration of 1,3- enynes are described. In the second chapter, the first intermolecular site-, regio- and transselective chloroboration and cyanoboration of enynes that are enabled by the Pd/Senphos catalytic system are presented. The cyanoboration products, namely vicinal boronsubstituted alkenylnitriles, are demonstrated as versatile synthetic building blocks. In the last chapter, the κ2-P-η2-B,C coordination behavior in a series of 1,2-, 1,3- and 1,4-Senphos ligated Pd(0) or Pd(II) complexes are evaluated based on solid-state structures and variable-temperature NMR measurements
Thesis (PhD) — Boston College, 2021
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

16

Van, Der Drift Mijke Anne. "Nonnormative ethics : the dynamic of trans formation." Thesis, Goldsmiths College (University of London), 2018. http://research.gold.ac.uk/24556/.

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In this thesis I propose to address trans as nonnormative ethical formation. In the current definition (Stryker, 2008) trans is defined as a movement outside of constraints that encapsulate normative genders. Preciado (2012) argues that trans involves the constitution of a soma-political project, beyond identity. As opposed to theories that describe identity formation as aspirational, the thesis extends Aristotle’s arguments for ethical formation in terms of interactive engagement within environments through an agents’ dunamis – the powers of its Soul (Lee 1992). The limits of the Aristotelian model will be overcome by use of Anzaldúa (1987) and Lugones (2003). The navigation away from imposed normative environments through agential action will be shown to lead to nonnormative logos: a formational logic shaping perception, action, and practical reflection culminating in practical truth. This reading enables centering somatechnical processes (Sullivan 2009) as generative of forms of life. Wittgenstein suggests that agential logic informs forms of life, shaping validity of both principles and decisions. I use this insight to claim that the polis is ordered by a single logic that informs norms. I propose nonnormative ethics to encompass agents with differing logos. Reading eudaimonia as the demon standing behind the agent, I will suggest that nonnormative ethics takes place outside of the polis on the ‘demonic grounds’ (McKittrick 2015, Wynter 1990). Nonnormative ethical connections are multilogical and are bridged by collective codes. I will draw from Glissant (2002) to make a case for acknowledging agential opacity away from a pathologising claim to interiority. I will argue for nonantagonistic playfulness and loss (Lugones, 2003) as keys to the emergence of nonnormative codes enabling shared forms of life. I propose that the distinction with the codes of the polis is the willingness to share loss, instead of exploitation. The thesis makes the case that bodily change is central to changing one’s understanding of, and relation to one’s surroundings. Furthermore, I argue such change is a collective process, and that emerging epistemologies are connected to contextual ethics.

17

McElroy, Craig Alan. "Dynamics and function mechanistic studies of the gene regulatory proteins TRAP and anti-TRAP /." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1111429539.

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Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xv, 327 p.; also includes graphics (some col.) Includes bibliographical references (p. 315-327). Available online via OhioLINK's ETD Center

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Gianfrancesco, Omar. "Ion dynamics in a linear high field RFQ trap." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100609.

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A new linear high electric field radiofrequency quadrupole (RFQ) ion trap, dubbed HVTrap, was developed and tested to study the phase space properties of confined particles and determine the suitability of such a device as an ion source/delivery system for high-resolution time-of-flight (TOF) mass spectrometry and to test the possibility of high field RFQ beam cooling in an ion guide.
A segmented quadrupole rod structure was built and shown to easily withstand over 4kV between adjacent electrodes placed 1mm apart in 1x10 -4 Torr of helium buffer gas. An innovative resonating circuit design using hollow air-cored induction coils was used to simultaneously deliver the necessary RF and DC trapping potentials to the linear RFQ system as well as deliver the extraction voltages used to eject test ions (Cs+, m/z = 133) produced by a surface ionization source. The resulting ion bunches were delivered to a TOF system for time profile analysis using a multichannel plate detector. Optimal trapping parameters were found to vary with applied RF potentials and extraction voltages. The presence of helium buffer gas at pressures of 10-4 Torr and long cooling times, in the range of 500ms, were found to improve the number of detected ions.
A thermodynamic model of the confined ions was used to simulate the extraction process and follow the phase space evolution of the ejected particles through the TOF region. Analysis of the experimental data showed that confined Cs + ions reached equilibrium temperatures as low as 0.45 eV after 500ms cooling periods in 1x10-4 Torr of helium buffer gas. These equilibrium temperatures were also found to be dependent on the number of detected ions and applied RF potentials. Harmonic frequencies in the resonant circuit are thought to play an important role in determining the thermal energies of the trapped ions.
This thesis has shown that high field RFQ confinement of ions in buffer gas is indeed feasible and that trapped particles can be manipulated using DC fields superimposed on the RF. In its present form, the HVTrap would be capable of mass resolutions of roughly 1000. Beam cooling using a high field RFQ would also be possible and could potentially accommodate beam currents of up to 100nA. If the ion temperature could be reduced to 0.05 eV, TOF mass resolutions of 30 000 would be possible.

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Ptáčková, Michaela. "Optimalizace tras při rozvozu zásilek." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-264544.

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This thesis deals with optimization problems of the parcels distribution. This issue can be solved on the ground of traveling salesman problem whose mathematical and economic model, including their modifications, are presented in the theoretical part of the thesis. We can solve these problems by using exact methods, heuristic and metaheuristic algorithms. In the theoretical part are described traveling salesman problem, traveling salesman problem with time windows, traveling salesman problem with multiple time windows and dynamic traveling salesman problem including possible ways of solution. In the practical part we can find application of problems on the real example, when we are finding the shortest possible route for the PPL's employee under different assumptions. The solution is obtained by using solver Gurobi within the modelling system MPL for Windows. In conclusion of the thesis the results are summarized and models are compared with each other.

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Ryjkov, Vladimir Leonidovich. "Laser cooling and sympathetic cooling in a linear quadrupole rf trap." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1637.

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An investigation of the sympathetic cooling method for the studies of large ultra-cold molecular ions in a quadrupole ion trap has been conducted.Molecular dynamics simulations are performed to study the rf heating mechanisms in the ion trap. The dependence of rf heating rates on the ion temperature, trapping parameters, and the number of ions is obtained. New rf heating mechanism affecting ultra-cold ion clouds exposed to laser radiation is described.The saturation spectroscopy setup of the hyperfine spectra of the molecular iodine has been built to provide an accurate frequency reference for the laser wavelength. This reference is used to obtain the fluorescence lineshapes of the laser cooled Mg$^+$ ions under different trapping conditions.The ion temperatures are deduced from the measurements, and the influence of the rf heating rates on the fluorescence lineshapes is also discussed. Cooling of the heavy ($m=720$a.u.) fullerene ions to under 10K by the means of the sympathetic cooling by the Mg$^+$ ions($m=24$a.u.) is demonstrated. The single-photon imaging system has been developed and used to obtain the images of the Mg$^+$ ion crystal structures at mK temperatures.

21

Guan, Wenwei. "Selective adaptation and legitimacy : public-private dynamics in China's TRIPS compliance." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/7919.

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This dissertation examines China’s compliance with the WTO’s intellectual property regime –the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) –and its theoretical implications. The dissertation’s critical review of contemporary intellectual property philosophy at the beginning suggests that justifying intellectual property protection through Locke or Hegel’s property theories internalizes a theoretical paradox. While being recognized as self-sufficient private rights gives intellectual creations constitutional significance, it also traps the legal regime in an intrinsic dilemma of private-public confrontation. In contrast to WTO’s private-oriented perspective, China’s response to this private-public dynamics indicates a clear public interest orientation. This is evident in imperial China’s reliance on criminal and administrative but not civil protection for intellectual endeavors, in contemporary protection of Olympic Marks, and in the Ex Officio action system of enforcement in China’s TRIPS implementation. In addition, an empirical survey study suggests that China’s public-oriented cultural imperative shapes people’s ways of perceiving private rights from their social embedment, and further constructs people’s perception of intellectual property protection. Further jurisprudential analysis reveals that the self-sufficient ontology since the Enlightenment that constructed the modernity of law has shaped TRIPS’ self-sufficient private rights perspective. When private rights are made self-sufficient and the intellectual property regime becomes indifferent to public concerns and development, modern law becomes “self-evident” and legitimacy collapses into legality. This public-private orientation contrast between China and the WTO not only explains the “how” and the “why” of China’s TRIPS compliance, but also reveals a compliance paradox. While foreign pressure on China for establishing an omnipotent administration to protect private-rights-in-nature intellectual property is squaring a circle in vain, China’s effort to embrace the private rights oriented regime is cutting off its toes to fit into foreign shoes. The dissertation proposes a jurisprudential reconstruction building on a relational instead of self-sufficient ontology to restore international compliance to the process of constant “selective adaptation” and dynamic growth of legitimacy. During this process, the dynamics between international norms and local imperatives provides a driving force for law’s development, where “to be” meets with “ought to be,” through which international norms and local regimes evolve.

22

Phillips, Eoin Seymour Gwyn. "Controlled dynamics of laser-cooled ions in a Penning trap." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419856.

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23

Stutter, Graham. "Quantum dynamics of small numbers of ions in a Penning trap." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/31473.

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Laser-cooled trapped ions are one of the main systems used in experiments in the fields of quantum optics and quantum information. There are two commonly-used types of ion trap, the radiofrequency trap and the Penning trap. In general, the RF trap has been more widely used in quantum information experiments, meaning that the set of experimental tools for conducting these types of experiments in a Penning trap is currently less complete. The aim of the work presented in this thesis is to increase this array of tools. Our experiment uses 40Ca+ ions in a Penning trap alongside lasers. Spectroscopy has been performed on single Doppler cooled ions, and on ions that have been prepared close to their ground state of motion using a multiple-stage sideband cooling technique resulting in an average phonon occupation number of $\nzbar = 0.029\pm 0.011$ from an initial $\nzbar \approx 24$. This corresponds to a quantum ground state population of $97\%$, which is close to the sideband cooling limit in our system. An axial heating rate measurement of $\dot{\bar{n}}_z=\SI{0.56\pm0.52}{\per\second}$ has also been obtained, which is the lowest recorded to date, due in part to the large dimensions of our trap. Additionally improved control of the Penning trap radial motion has been demonstrated and the average phonon occupation number of the modified cyclotron motion has been reduced from $\ncbar\approx150$ after Doppler cooling to $\ncbar=0.6$ after sideband cooling. Some preliminary single-ion coherent operations have also been performed. In the future we hope that this system of ground state cooled ions in a Penning trap can be used to generate highly-entangled states in two or more ions, with a view to performing simple quantum error-correcting codes and eventually an analogue quantum simulation of spin systems.

24

Buis, Arjan W. P. "Dynamic interface pressure measurement : comparing two trans-tibial socket concepts." Thesis, University of Strathclyde, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341806.

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25

Schnoering, Gabriel. "On the Brownian dynamics of a particle in a bistable optical trap." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF057/document.

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Cette thèse présente la réalisation d’un piège optique dans une configuration originale, le piston optique, où le contrôle sur la phase de l’interférence d’un faisceau incident avec sa réflexion sur un miroir permet de réaliser différents types d’expériences. Nous avons d’abord étudié les propriétés thermodynamiques d’une compression progressive du piston qui fait passer la dynamique de la particule piégée d’une région de stabilité vers une région de bistabilité mécanique. Dans le contexte de la résonance stochastique où une force extérieure périodique est appliquée sur cette dynamique bistable, une approche exploitant le facteur de Mandel ainsi qu’une analyse des délais entre les transitions d’états métastables se révèle efficace pour interpréter nos mesures dans différents régimes de forçage. Nous montrons également comment des nanoparticules métalliques peuvent être piégées aisément dans un tel piston optique et nous exploitons notre configuration pour mesurer de faibles effets de forces optiques. Enfin, nous piégeons des nano-objets chiraux uniques et nous montrons comment la configuration de notre piston permet de réaliser des expériences de reconnaissance chirale par polarimétrie différentielle
This thesis describes the experimental realization of an original optical trap, the optical piston, where controlling the phase of the interference of an incident beam with its reflection on a mirror allows achieving various experiments. We have first looked into the thermodynamics associated with a progressive compression of the piston leading the dynamics of a trapped particle from a region of stability to a region of mechanical bistability. In the context of stochastic resonance where a periodic external force is applied on this bistable dynamics, an approach exploiting the Mandel factor and a time-delay analysis on the hopping events between metastable states have proven efficient in interpreting the different results acquired in different regimes of drive. We have also shown how metallic nanoparticles can be trapped fairly easily in this kind of optical piston and we exploit our configuration to measure weak optical forces. Finally, we trap unique chiral nano-objects and we show how the configuration of our piston allows the realization of chiral recognition experiments by differential polarimetry

26

Hendricks, Richard James. "Spectroscopy and dynamics of laser-cooled Ca+ ions in a Penning trap." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437241.

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27

Unnikrishnan, Aparna. "INVESTIGATION OF PROTEIN STRUCTURE AND DYNAMICS BY NMR SPECTROSCOPY." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595418229203869.

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28

Kleckner, Ian Robert. "Thermodynamic, Kinetic, and Dynamics Studies of the Allosteric Ligand-Responsive Regulatory Protein TRAP." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313460041.

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29

Marshall, Tracey. "Dynamic chemistry : nucleobase recognition by synthetic receptors and cis-trans acylhydrazone isomerism." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14477/document.

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Chimie dynamique: reconnaissance de nucléobases par des récepteurs synthétiques et isomérie cis-trans d'hydrazones acylées.Ce travail traite du développement des systèmes moléculaires qui peuvent s'adapter à l'addition de substances qui agissent comme un gabarit. Cette approche permet d'isoler une espèce majeure à partir d'un mélange de composés par le biais de la chimie combinatoire dynamique (CCD). La première partie de ma thèse de doctorat inclus l'utilisation d'un ADN simple brin (ADNsb) comme un gabarit pour le transfert d'information par auto-assemblage de récepteurs sans avoir besoin d'enzyme. De nouveaux récepteurs de l'adénine et de la guanine (pinces A et G) solubles dans l'eau ont été conçues dans ce but. Une approche utilisant la résonance magnétique nucléaire (RMN) a été utilisée pour déterminer l'affinité de liaison comme preuve d'une reconnaissance spécifique et efficace. Une évaluation dans l'eau par dichroïsme circulaire (CD) et mesure de la température de fusion par UV (Tm) a été réalisée. Cela a permis de tester respectivement la capacité d'auto-assemblage entre les pinces et un modèle ADNsb, et la force du processus de coopérativité. La deuxième partie de ce travail est axée sur le tri spontanné de motifs pyridine acylhydrazone et sur les configurations intéressantes qu'ils adoptent. Nous avons étudié la synthèse d'une série de motifs pyridine acylhydrazone: dimère, trimères et pentamères. Des études RMN ont permis d'évaluer les changements dans l'équilibre configurationnel cis / trans de ces systèmes dynamiques. Les études ont montré que l'équilibre attendu est biaise la cis acylhydrazone pyridine isomère a été observée par diffraction des rayons X
Dynamic chemistry: nucleobase recognition by synthetic receptors and cis-trans acylhydrazone isomerism. This work deals with the development of molecular systems which can adapt upon the addition of substances that act as templates. This approach enables one major species to be identified from a mixture of compounds through the use of dynamic combinatorial chemistry (DCC). The first part of my PhD included the use of a single stranded DNA (ssDNA) as a template for information transfer via the self-assembly of receptors without the need for enzymes. New water soluble adenine and guanine receptors (A and G clamps) were designed and synthesised for this purpose. Nuclear magnetic resonance (NMR) titration studies were carried out to calculate the binding affinity and as a proof of specific and efficient recognition. An assessment in water via circular dichroism (CD) and UV temperature melting (Tm) studies was carried out. This tested the ability for self-assembly between the clamps and a ssDNA template and the strength of the cooperative process respectively. The second part of my PhD focused on the self-sorting of acylhydrazone pyridine motifs and the interesting configurations they adopt. The feasibility to synthesise these acylhydrazone pyridine motifs (dimer, trimers and pentamers) was investigated. X-ray and NMR studies showed that the equilibrium was found to be biased in an unusual way, and the cis acylhydrazone pyridine isomer was observed

30

New, Cherie Lynn. "A metapopulation dynamics model for black bear recolonization in the Trans-Pecos region of Texas." Thesis, Sul Ross State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1526975.

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West Texas, especially the Trans-Pecos region, mainly consists of desert shrubs and grasslands with patches of higher elevation (1,500 – 2,000 m) mountain ranges. Black bears (Ursus americanus) were extirpated from this area by the 1940s because of predator control and over hunting. In the 1980s, black bears returned to west Texas in a natural recolonization movement from Mexico, where they had survived. The black bear populations of the Trans-Pecos region and northern Mexico fit a mainland-island metapopulation model. Based on previously published research on this recolonization event, I identified several likely habitat recolonization sites and corridor routes for use in predicting possible black bear dispersal throughout the area. Then, using these corridor and recolonization scenarios, I produced a black bear metapopulation model for the Trans-Pecos region.

The possible habitat recolonization site map was created by combining 2 habitat suitability index (HSI) maps and using these HSI maps to define 'core' and 'useable' black bear habitat within the Trans-Pecos region. Using these locations, along with dispersal probabilities and black bear demographic parameters, I created a corridor dispersal map of the area using the program Circuitscape.

The metapopulation model was created using STELLA modeling software. Each recolonization location in the Trans-Pecos region (Big Bend National Park, Black Gap Wildlife Management Area, and the Davis Mountains) has its own black bear subpopulation. The metapopulation model is a stochastic compartment model based on a yearly time step (Δt = 1 yr). This model was tested for the effects of: carrying capacity per site, immigration rates from Mexico, rates of dispersal from Black Gap Wildlife Management Area to the Davis Mountains, and the recovery time for the area after complete extirpation from the Trans-Pecos. This information will help local biologists conserve and manage these returning black bears in the Trans-Pecos region.

31

Fong, C. W. Van (Chun Wan Van) 1973. "Phase space dynamics in a linear RFQ trap for time-of-flight mass spectrometry." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36924.

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A new Linear RFQ Ion Trap/Axial Time-of-Flight mass spectrometer was developed and tested. A segmented quadrupole rod system was used to create a static axially confining field that could trap and cool an ion cloud from a DC ion source. In addition, an adjustable extraction field was applied, after sufficient ion collection, by pulsing the trapping rod segments to send the cooled ion cloud into a collinear Time-of-Flight spectrometer. Two chevron stacked multichannel plates, with a measured charge amplification of 3.75 x 107, were used as a detector at the end of the flight tube.
The purpose of this work was to investigate ion dynamics in the linear trap (LTRAP) so as to determine the suitability of this system as a source for TOFMS. The trap was therefore designed to be relatively weak so that the ion collection volume would be large enough to obtain a detailed picture of the cloud. The system was tested using a Cs+ (m/ z =133) ion source. Optimal parameters were found to be an applied well depth of -5V to -15V with a q value between 0.3 and 0.6 in a buffer gas environment of N2 at pressures of 10 -4 Torr or greater. Under these conditions and a cooling/collection time of 50ms the trap was observed to contain about 2500 ions. This translated to a detection efficiency of about 26.7% of the ions entering LTRAP.
Computer simulations based on a thermodynamic model were created to analyze the experimental data. The ion ensemble was found to reach an equilibrium temperature of 0.0353 +/- 0.0025eV in less than 10ms. Another computer program was used to reconstruct the phase space density of the LTRAP collection from the detector signals. The results of this reconstruction agreed with the results obtained from the model fitting procedure thereby confirming the thermodynamic model.
The phase space density distribution in LTRAP showed that with a time-focusing reflectron even this weak trap would have a m/Delta m = 250. This has led to guidelines for the construction of a high-resolution hybrid mass spectrometer using a linear ion trap. Based on these current results, a mass resolution of almost 10,000 is predicted as an upper limit of this type of mass spectrometer.

32

Soprani, Lorenzo. "A study of the trans-cis photoisomerization mechanism of azobenzene in liquid crystals." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16671/.

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In this work we have studied, by means of Molecular Dynamics simulations, the trans-cis photoisomerization mechanism of azobenzene dissolved in a liquid crystal when excited in the state associated to the npi* transition (first excited singlet S1). A great number of photochemical applications are based on the trans-cis photoisomerization of azobenzene-containing materials, and, in particular, liquid crystals, and even though many studies have been done, the actual conversion mechanism in condensed phases is still not completely known. Herein, with the purpose to continue the work of Tiberio et al., which analyzed the npi* photoisomerization in vacuum and in various organic solvents, we start the study of the same phenomenon taking place in a liquid crystal (8CB) via a modifed molecular dynamics simulation adopting a QM-based class II force field in the ground and excited state, electronic transitions and stochastic decay events to the fundamental state. We describe the procedure used to parameterize the new force field for azobenzene in ground and first excited state, analyze the molecular trajectories, determine the trans-cis photoisomerization quantum yield and decay times and compare our results with experimental ones where available. Quantum mechanics calculations showed that it is fundamental in the decay pathway to reach a molecule conformation in which the central dihedral angle CNNC is about 90° and the two bending angles CNN are asymmetric. With molecular dynamics simulations we see that this mechanism is followed, although with some differences, in vacuum as well as in 8CB.

33

Kim, Dae Sin. "Monte Carlo Modeling of Carrier Dynamics in Photoconductive Terahertz Sources." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11526.

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Carrier dynamics in GaAs-based photoconductive terahertz (THz) sources is investigated using Monte Carlo techniques to optimize the emitted THz transients. A self-consistent Monte Carlo-Poisson solver is developed for the spatio-temporal carrier transport properties. The screening contributions to the THz radiation associated with the Coulomb and radiation fields are obtained self-consistently by incorporating the three-dimensional Maxwell equations into the solver. In addition, the enhancement of THz emission by a large trap-enhance field (TEF) near the anode in semi-insulating (SI) photoconductors is investigated. The transport properties of the photoexcited carriers in photoconductive THz sources depend markedly on the initial spatial distribution of those carriers. Thus, considerable control of the emitted THz spectrum can be attained by judiciously choosing the optical excitation spot shape on the photoconductor, since the carrier dynamics that provide the source of the THz radiation are strongly affected by the ensuing screenings. The screening contributions due to the Coulomb and radiation parts of the electromagnetic field acting back on the carrier dynamics are distinguished. The dominant component of the screening field crosses over at an excitation aperture size with full width at half maximum (FWHM) of ~100 um for a range of reasonable excitation levels. In addition, the key mechanisms responsible for the TEF near the anode of SI photoconductors are elucidated in detail. For a given optical excitation power, an enhancement of THz radiation power can be obtained using a maximally broadened excitation aperture in the TEF area elongated along the anode due to the reduction in the Coulomb and radiation screening of the TEF.

34

Bharadia, Shailen. "Towards laser spectroscopy of highly charged ions : dynamics of 40Ca+ ions in a Penning trap." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9138.

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To date, the most successful quantum field theory is quantum electrodynamics (QED) which offers a fully quantum mechanical description of the electromagnetic interaction between charged particles. Laboratory tests of the theory have been performed for a wide range of field strengths and no significant deviation from the predictions of the theory have been found. For heavy highly charged ions (HCI), the electric and magnetic fields around the nucleus can be orders of magnitude higher than those achievable by conventional means in a laboratory. Therefore, these ions offer a new regime in which the theory should be tested. For HCI above Z > 60, the ground state hyper fine structure splitting (HFS) shifts into the optical region, and becomes accessible to laser light sources. The aim of the SPECTRAP experiment at GSI in Germany, is to perform laser spectroscopy of the HFS in H-like and Li-like HCI, as a test of the corresponding bound-state QED calculations. In order for this to be successful, the weak magnetic HFS transitions need to be measured to a high precision. This will be accomplished in the SPECTRAP experiment by trapping and cooling bunches of HCI, such that the relative precision of the measured transition will be on the level of 10-7, allowing bound-state high order QED calculations to be tested to the level of a few percent. As fluorescence rates will be low, a critical final part in preparing the ions in the trap will be the application of a rotating dipole ('rotating wall') about the magnetic field axis allowing for compression of the ion cloud in the trap, thereby increasing the fluorescence collection efficiency and signal to noise for detection. In London, due to the availability of our own superconducting magnet, we have performed systematic measurements of the dynamics of laser cooled Ca+ ions confined in a Penning trap driven by a rotating wall. With CCD camera imaging, we have measured the fluorescence from a cloud of ions, identified as being a strongly correlated non-neutral plasma, as a function of the rotating wall drive amplitude, frequency, sense of rotation and trap potential. We show that a cloud driven at sufficient amplitude reaches a low-slip regime within the time frame of a single CCD exposure (~ 1s), and that heating resonances are observed on scanning the rotation frequency. These resonances are identified as being associated with the axial motion of the ions in the trap potential, and the lowest order azimuthal plasma modes which are believed to be excited indirectly by a misalignment of the electric and magnetic fields. By operating the rotating wall in the opposite sense of rotation to that used for cloud compression, the excitation of these plasma modes is shown to be a good diagnostic probe of the laser cooled rigid rotation frequency of the cloud, allowing the number density to be inferred from the measurement. These results will allow the SPECTRAP collaboration to define a procedure and set of optimum parameters for use of the rotating wall technique that offers maximum compression of ions needed for the precision spectroscopy of HCI. These results have been accepted for publication in Applied Physics B [1], and were presented at the European Conference for Trapped Ions in September 2010. The in-vacuum confocal fluorescence collection optical design proved valuable in alignment of the imaging system outside the magnet, and successful in increasing the detected fluorescence rates. As a result, the optical design and techniques employed here, have been successfully transferred to the GSI experiment. We also present simulations conducted to optimise the transport and in- flight capture of HCI into the SPECTRAP ion trap from the HITRAP facility at GSI, and report on the first attempts at trapping singly charged Mg+ and Ar+ ions, testing the ability of the system to capture, localise and cool ions.

35

Dhaibi, Youssef. "Optische elektronische Eigenschaften leitender Polymere." Doctoral thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961994126.

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36

Hussain, Nibras. "The Dynamic Behaviour of a Nitrogen Oxide Trap for Direct Injection Gasoline Engine." Thesis, University of Sussex, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487971.

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37

Laskay, Ünige A. "Dynamic Collision Induced Dissociation - A Novel Fragmentation Method in the Quadrupole Ion Trap." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1230577624.

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38

Laskay, Ünige A. "Dynamic collision induced dissociation : a novel fragmentation method in the quadrupole ion trap /." View abstract, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3353544.

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39

Ludwig, Scott W. "Role of trap crops on harlequin bug, Murgantia histrionica (Hahn), population dynamics and parasitism in broccoli plots." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-05022009-040744/.

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40

Bernier, Jobe Paul. "Entropy and Architecture entropic phenomena actuating dynamic space /." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/bernier/BernierJ0508.pdf.

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41

Chong, Sing Hwa Zewail Ahmed H. Zewail Ahmed H. "Ultrafast dynamics of barrier crossing : step-wise solvation effect on isomerization of trans-stilbene in alkane clusters /." Diss., Pasadena, Calif. : California Institute of Technology, 2001. http://resolver.caltech.edu/CaltechETD:etd-04072008-151825.

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42

Burger, Abri Andre Spies. "Numerical analysis of flow around infinite and finite cylinders at trans-critical Reynolds numbers with and without surface roughness." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97053.

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Thesis (MEng)--Stellenbosch University, 2015.
ENGLISH ABSTRACT: This thesis investigates the flow field and pressure distributions around cylinders at trans-critical Reynolds numbers using the k-ε Realizable turbulence model. A steady state 2-D and 3-D Fluent® model is successfully developed to evaluate the effects of changing various modelling parameters on the static pressure distribution around an infinite and finite cylinder. These parameters include surface roughness, cylinder rotation and air viscosity at the cylinder surface. The subsequent results obtained are compared to each other and to data trends from literature as well as measured experimental results and are found to be in good agreement. In addition a method for calibrating all developed methods based on their shear stress curves over a flat plate model is also successfully developed. The main objective is to find an appropriate single parameter which can be used for the rigorous adjustment of the pressure distribution around a cooling tower, which will allow for improved sensitivity analysis and modelling of cooling tower performance under wind conditions with and without meridional ribs located on the outer shell surface.
AFRIKAANSE OPSOMMING: Hierdie tesis ondersoek die vloeiveld en druk verdelings rondom silinders by trans-kritiese Reynolds getalle deur gebruik te maak van die k-ε Realizable turbulensie model. ‘n Bestendige toestand 2-D en 3-D Fluent® model is suksesvol ontwikkel om die uitwerking van die verandering van verskeie model parameters op die statiese druk verdeling rondom ‘n oneindige en eindige silinder te evalueer. Die laasgenoemde parameters sluit in oppervlak grofheid, silinder rotasie en lug viskositeit by die silinder wand. Die daaropeenvolgende resultate wat verkry word, word met data tendense uit die literatuur asook gemete data vanuit eksperimente vergelyk en goeie ooreenkoms i.t.v die data tendense is gevind. Verder is ‘n metode vir die suksesvolle kalibrasie van die ontwikkelde numeriese tegnieke ontwikkel. Die laasgenoemde kalibrasie metode is gebaseer op die vergelyking van skuifspanning kurwes vir vloei oor ‘n plat plaat model. Die hoofdoel van die navorsing is om ‘n geskikte enkele parameter te vind wat gebruik kan word vir die effektiewe aanpassing van die druk verdeling rondom ‘n koeltoring wat sal lei tot verbeterde sensitiwiteits analise en modellering van koeltoring verrigting onder wind toestande met en sonder meridionale ribbes geleë op die buitenste dop oppervlak.

43

Hashemloo, Avazeh. "Numerical simulation of the dynamics of a trapped molecular ion." Doctoral thesis, Umeå universitet, Institutionen för fysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-118899.

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This thesis explores the dynamics of a heteronuclear diatomic molecular ion, possessing a permanent electric dipole moment, µ, which is trapped in a linear Paul trap and can interact with an off-resonance laser field. To build our model we use the rigid-rotor approximation, where the dynamics of the molecular ion are limited to its translational and rotational motions of the center-of-mass. These dynamics are investigated by carrying out suitable numerical calculations. To introduce our numerical methods, we divide our research topic into two different subjects. First, we ignore the rotational dynamics of the ion by assuming µ = 0. By this assumption, the system resembles an atomic ion, which mainly exhibits translational motion for its center of the mass when exposed to an external trapping field. To study this translational behavior, we implement full-quantum numerical simulations, in which a wave function is attributed to the ion. Finally, we study the quantum dynamics of the mentioned wave packet and we compare our results with those obtained classically. In the latter case, we keep the permanent dipole moment of the ion and we study the probable effects of the interaction between the dipole moment and the trapping electric field, on both the translational and the rotational dynamics of the trapped molecular ion. In order to study these dynamics, we implement both classical and semi-classical numerical simulations. In the classical method, the rotational and the translational motions of the center of mass of the ion are obtained via classical equations of motion. On the other hand, in the semi-classical method, while the translational motion of the center-of-mass is still obtained classically, the rotation is treated full-quantum mechanically by considering the rotational wave function of the ion. In the semi-classical approach, we mainly study the probable couplings between the rotational states of the molecular ion, due to the interaction of the permanent dipole moment with the trapping electric field. In the end, we also present a semi-classical model, where the trapped molecular ion interacts with an off-resonance laser field.

44

Guillon, Thomas. "Calculs DFT et propriétés électriques de complexes à transition de spin." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/813/.

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Les complexes à transition de spin présentent un phénomène de bistabilité moléculaire entre deux états de spin (états bas-spin et haut-spin) énergétiquement proches. Ils suscitent un grand intérêt pour de nombreuses applications possibles dans les domaines de l'électronique et de l'optique. Les méthodes basées sur la théorie de la fonctionnelle densité (DFT) ont montré leur efficacité dans le calcul des structures moléculaires, le calcul des fréquences des modes de vibration et des déplacements fréquentiels dus à une substitution isotopique ainsi que la possibilité d'attribuer tous les modes de vibration, le calcul des propriétés thermodynamiques. . . Comme le présentent nos études sur les complexes à transition de spin [Fe(phen)2(NCS)2], Fe[5-NO2-sal-N(1,4,7,10)], [Fe(L)(CN)2]. H2O, [Fe(TRIM)2]2+, [Fe(bpp)2]2+ et [Fe(PM-BiA)2(NCS)2]. En outre, nos calculs DFT démontrent leur potentiel dans la prédiction de propriétés structurales particulières pour des complexes de taille importante telles que l'existence de conformères pour le complexe Fe[5-NO2-sal-N(1,4,7,10)] ou l'existence d'un changement de coordinence (6 - 7) avec le changement d'état de spin pour le complexe [Fe(L)(CN)2]. H2O, confirmant ainsi des suggestions ou des résultats expérimentaux. Enfin, nous avons déterminé les propriétés électroniques microscopiques à l'aide de méthodes DFT grâce aux calculs de tenseurs de polarisabilité. Ces calculs nous ont permis de mettre en évidence et de confirmer l'origine microscopique des propriétés diélectriques mesurées accompagnant la transition de spin, et de comprendre les comportements atypiques de la variation thermique de la permittivité diélectrique de certains matériaux à transition de spin
The spin-crossover complexes exhibit a phenomenon of molecular bistability between two spin states (low-spin and high-spin states) energetically very close. They are of great interest for many potential applications in the fields of electronics and optics. The methods based on density functional theory (DFT) have proved to be efficient in the calculation of molecular structures, the calculation of vibrational frequencies modes, frequency shifts due to isotopic substitutions and the ability to assign all vibrational modes, the calculation of thermodynamic properties. . . As presented by our studies on the [Fe(phen)2(NCS)2], Fe[5-NO2-sal-N(1,4,7,10)], [Fe(L)(CN)2]. H2O, [Fe(TRIM)2]2+, [Fe(bpp)2]2+ and [Fe(PM-BiA)2(NCS)2] spin crossover complexes. Furthermore, our DFT calculations results demonstrate their potential in specific structural properties prediction for large size complexes such as the existence of conformers for the Fe[5-NO2-sal-N(1,4,7,10)] complex or the existence of a coordination number (6 - 7) change with the spin states change for the [Fe(L)(CN)2]. H2O complex, confirming suggestions or experimental results. Finally, we determined the microscopic electrical properties using DFT methods with the calculations of polarizability tensors. These calculations allowed us to identify and confirm the microscopic origin of the measured dielectric properties accompanying the spin transition, and understand the atypical behaviour of the dielectric permittivity thermal variation of some spin-crossover compounds

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Suskind, Naomi. "Trans-formative support a grounded theory examination of the interpersonal and family dynamics of people who are transgender /." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1464458.

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46

Silveira, Mariana Rodrigues da. "A dinamica por tras da sequencia espectral." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307546.

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Orientador: Ketty Abaroa de Rezende
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
Made available in DSpace on 2018-08-10T21:02:39Z (GMT). No. of bitstreams: 1 Silveira_MarianaRodriguesda_D.pdf: 1531895 bytes, checksum: 3c73a8eb791483b1f0216d6f2627969b (MD5) Previous issue date: 2008
Resumo: Neste trabalho, apresentamos um algoritmo para um complexo de cadeias C e sua diferencial dada por uma matriz de conexão _ que determina uma seqüência espectral associada (Er, dr). Mais especificamente, um sistema gerador de Er em termos da base original de C é obtido bem como a identificação de todas as diferenciais dr p : Er p ! Er p-r. Explorando a implicação dinâmica da diferencial não nula, mostramos a existência de um caminho unindo a singularidade que gera E0 p e a singularidade que gera E0 p-r no caso em que a conexão direta pelo fluxo não existe. Este caminho é composto pela justaposição de órbitas do fluxo e do fluxo reverso e prova ser importante em algumas aplicações
Abstract: In this work, we present an algorithm for a chain complex C and its di_erential given by a connection matrix _ which determines an associated spectral sequence (Er, dr). More specifically, a system spanning Er in terms of the original basis of C is obtained as well as the identi_cation of all di_erentials dr p : Er p ! Er p-r. In exploring the dynamical implication of a nonzero di_erential, we prove the existence of a path joining the singularities generating E0 p and E0 p-r in the case that a direct connection by a _ow line does not exist. This path is made up of juxtaposed orbits of the _ow and of the reverse _ow and which proves to be importantin some applications
Doutorado
Geometria e Topologia/Sistemas Dinamicos
Doutor em Matemática

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Mathias, Gertraut. "Neuropsychologisches Outcome nach koronarer Bypass-Operation unter Anwendung einer neuartigen dynamischen Luftfalle (dynamic bubble trap)." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969802064.

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Hernandez, Pozos Jose Luis. "Dynamics of Mgâº and Beâº trapped ions and design and construction of a cylindrical Penning trap." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407205.

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Karmacharya, Binab. "Population Dynamics of Northern Cardinal and Carolina Wren in an Urban Forest Fragment| Safe Refuge or Ecological Trap?" Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10002466.

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Conserving bird populations in urban landscapes often depends on interactions between extinction, recolonization, and survival in remnant habitat patches such as small nature preserves. Thus, determining the ecological value of small nature preserves to birds is a necessary step towards an informed conservation strategy. As such, I conducted a year round capture-mark-recapture study from April 2010 to March 2014 to examine population dynamics of Northern Cardinals (Cardinalis cardinalis) and Carolina Wrens ( Thryothorus ludovicianus) in a 41.7-ha nature preserve embedded in an urban matrix. More specifically, we examined variation in survival, recruitment, and realized population growth rates relative to year, season, sex, age, and wing length (as a proxy for body size) to investigate attributes that affect individual survival and to assess whether the reserve served as a population source or sink. The overall annual apparent survival rate of Northern Cardinals (0.520 ± SE 0.050) was higher than that of the Carolina Wrens (0.349 ± 0.050), and estimates in both species were similar to regional baseline estimates. The survival rates for adults were significantly higher than for immatures in both species, with body size having a positive influence on survival. Seasonal variation in survivorship was evident only in Northern Cardinals, being highest in the winter and lowest during the breeding season. Average annual population growth rate was slightly greater than 1.0 for both species, indicating stable or perhaps modestly increasing populations. These results represent the first published full annual cycle estimates of survival and population growth relative to age, sex, and body size for non-migratory passerines. Our results suggest that urban forests can provide the necessary resources to sustain growing populations of locally common birds. Furthermore, our demographic estimates derived from two healthy bird populations can serve as target values for other species of conservation concern within human-modified landscapes.

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Vadluga, Vaidas. "Simulation of dynamic deformation and fracture behaviour of heterogeneous structures by discrete element method." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080213_082157-83281.

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Research area and topicality of the work. Mechanical properties and their evolution under loading are the most significant factors for the development of various mechanical structures, technologies and equipment. It seems to be natu-ral that deeper understanding of the behaviour of existing and design of new materials presents a challenge in different research areas. It should be noted, that all the materials are heterogeneous in meso- and micro- scales. They exhibit essential differences, compared to the macroscopic continuum behaviour. Basically, both experimental and numerical simulation methods are extensively applied for investigation purposes. Experimental techniques, capable of giving a realistic view of the inside of the material and extracting the real data, are very expensive. Therefore, the nu-merical simulation tools are extensively used as an alternative for investigation purposes. They have considerable advantages allowing the reproduction of multiple experiments and providing comprehensive data about ongoing phe-nomena. Recently, numerical technologies have become highly multidisciplinary subjects. They comprise phenomenological and statistical ideas, while mathe-matical models employ the relations of continuum mechanics, classical discre-tization methods and molecular dynamics. The Discrete Element Method (DEM) is one of new methods. It is aimed at simulating the dynamic behaviour of the contacting particles. Variable topology of the system of particles is an... [to full text]
Tyrimų sritis ir darbo aktualumas. Kuriant modernias ��vairios paskirties mechanines sistemas, technologijas ir įrangą, svarbiomis tampa jas sudarančios medžiagos. Savaime suprantama, kad žinomos ir naujai kuriamos medžiagos dabar kur kas išsamiau nagrinėjamos daugelyje mokslo šakų, įskaitant ir me-džiagų mechaniką. Visos medžiagos mezo- ir mikrostruktūros požiūriu yra ne-vienalytės. Jų mikroskopinės savybės skirtingos, lyginant su įprastu kontinuu-mu. Medžiagų savybėms tirti dažniausiai taikomi eksperimentiniai metodai. Eksperimentiniais metodais ištirti medžiagos struktūras ir jose vykstančius procesus ir įvertinti tam tikras jų savybes labai brangu. Tai viena priežasčių, kodėl skaitinis modeliavimas tampa realia tyrimų alternatyva. Skaitinį eksperi-mentą galima kartoti daug kartų, valdant bandinio parametrus, išlaikant tas pa-čias sąlygas, ir stebėti reiškiniui būdingus rodiklius visame tūryje. Šiuolaikiniai modeliavimo metodai yra kompleksiniai. Jie jungia fenome-nologines ir statistines idėjas, o matematiniai modeliai sudaromi taikant konti-nuumo mechanikos ir jų diskrečiųjų modelių bei molekulinės dinamikos pri-klausomybes. Diskrečiųjų elementų metodas (DEM) taip pat priskiriamas šiuo-laikinių metodų kategorijai. Jis skirtas kontaktuojančių dalelių sistemų dinami-niam modeliavimui. Kintanti dalelių sistemos topologija – būdingas metodo požymis. Pastaruoju metu DEM jau taikomas kontinuumui modeliuoti ir praktikoje aktualiems irimo uždaviniams spręsti. Reikia pastebėti... [toliau žr. visą tekstą]

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