Dissertations / Theses on the topic 'Equivalence principles'

A thorough treatment of the Strong Equivalence Principle is presented, demonstrating its failure in dealing with non-uniform gravitational fields. In particular, a calculation utilising the equivalence principle is shown to produce an incorrect rate of deflection of light. This calculation is used as a tool to investigate the nature of this deflection, and the meaning of the Strong Equivalence Principle. Using a generalised metric for outside a static, spherically symmetric gravitational source, it is shown that the failure of the equivalence principle is geometric and not due to any particular choice of metric. When transformed into a displaced rectangular coordinate system, the generalised metric consists of both diagonal and off-diagonal elements. Only the diagonal elements are equivalent to a flat, uniformly accelerating frame. The off-diagonal elements produce non-zero elements in the Riemann Curvature Tensor and are thus attributed to curvature. Therefore, the Strong Equivalence principle is only valid in the weak field limit, where the components of the Riemann curvature tensor vanish. In this case the metric becomes flat, which is the equivalent of a uniform gravitational field. Using the Schwarzschild metric in displaced rectangular coordinates, the effect of curvature on the rate of deflection of light are determined by tracing the effect of the off-diagonal elements. This calculation shows that only one-third of the deflection rate is due to acceleration in the local inertial frame, with the remaining two-thirds being the result of curvature. Because the rate of deflection is is an infinitesimal quantity defined locally, this shows the effects of curvature are important even for local measurements.

The Equivalence Principle is accepted as one of the most fundamental principles in modern Physics. However, theories towards the unification of the four forces typically predict violations of this principle. Testing it at a high sensitivity is expected to make a breakthrough in the current understanding of Physics. A space-based project, STEP (Satellite Test of the Equivalence Principle), aims at testing the principle to the level of 10\(^{−18}\). This corresponds to an improvement of the current limits, established by ground-based experiments, by approximately five orders of magnitudes. To achieve the sensitivity, imperfections in STEP test masses, such as density inhomogeneity and thermal distortion, could be a problem. This thesis presents preliminary work on the verification of STEP test masses. We have measured density inhomogeneities in materials intended to be used as STEP test masses (beryllium and niobium). In addition, we have developed a device to measure differential thermal expansion of samples that cannot be machined, by using a capacitive sensing method. It is shown that the device has a precision of approximately 0.3 % in the differential thermal expansion of beryllium. This device could in principle be applied for the measurements of the real STEP test masses in the final shape. Our analysis based on the results of our measurements and literature survey shows that it is feasible to obtain materials that satisfy STEP requirements.

Durant ces deux dernières décennies, de nouvelles techniques pour refroidir et manipuler les atomes ont permis le développement de capteurs inertiels basés sur l'interférométrie atomique. Dans ce contexte, le projet ICE est basé sur l'utilisation d'un interféromètre atomique double espèce compacte et transportable dans le but de tester le principe d'équivalence faible. Nous comparons ainsi l'accélération de deux espèces chimiques et nous vérifions leur égalité en mesurant le paramètre d'Eötvös à un niveau de 10-6. Cette expérience a été réalisée en laboratoire et en micropesanteur lors de vols paraboliques à bord de l'Airbus A310 ZERO-G de Novespace. L'interféromètre est composé de deux échantillons de 87Rb et 39K refroidis par laser, possédant des longueurs d'onde de transitions atomiques similaires (780 nm et 767 nm) qui sont générées par un doublage de fréquence laser Télécom. Récemment, nous avons réalisé le premier interféromètre double espèce en micropesanteur. Cette expérience a ainsi permis le premier test du principe d'équivalence faible dans cet environnement en utilisant des objets quantiques, ce qui représente une première étape majeure vers une future mission spatiale. Dans le cadre de ces travaux, nous avons installé une source laser à 770 nm, accordée sur la transition D1 du 39K, afin de réaliser un refroidissement par mélasse grise. Nous avons également mis en place une nouvelle séquence pour préparer les atomes dans l'état mF = 0 avec une efficacité de transfert supérieure à 90%. Ces techniques ont amélioré le contraste de notre interféromètre de 39K d'un facteur 4, ce qui a mené à l'obtention d'une sensibilité sur le paramètre d'Eötvös dans le laboratoire de 5 x 10-8 après 5000 s d'intégration<br>During the last two decades, new techniques to cool and manipulate atoms have enabled the development of inertial sensors based on atom interferometry. In this context, the ICE project is based on a compact and transportable dual-species atom interferometer in order to verify the weak equivalence principle (WEP). Thus, we compare the acceleration of two chemical species and verify their equality by measuring the Eötvös parameter at the 10-6 level.This experiment was performed both in the laboratory and in the microgravity environment during parabolic flights onboard the Novespace ZERO-G aircraft. The interferometer is composed of laser-cooled samples of 87Rb and 39K, which exhibit similar transition wavelengths (780 nm and 767 nm) derived from frequency-doubled telecom lasers. Recently, we have performed the first dual species interferometer in microgravity. This enables the first test of the WEP in weightlessness using quantum objects, which represents a major first step toward future mission in space.As part of these experiments, we have implemented a 770 nm laser source, resonant with the D1 transition of 39K, in order to perform a gray molasses cooling. We have also devised a new sequence to prepare atoms in the mF = 0 state with a transfer efficiency above 90%. These techniques improved the contrast of our 39K interferometer by a factor 4, which led to the obtention of a sensitivity on the Eötvös parameter in the laboratory of 5 x 10-8 after 5000 s of integration

Vacuum polarization by electric fields is a well established fact. Assuming that anti-matter has negative gravitational properties, the fluctating electric dipoles from the quantum vacuum may also have gravitational dipolar properties. A model is developed that describes how electric fields could gravitationally polarize the vacuum causing gravitational screening or anti-screening effects. This leads to a violation of the Weak Equivalence Principle or a general mass change most notabily for elementary particles, such as the electron or positron, below but close to measured boundaries. Also a gravitational vacuum torque is predicted to act on a charged capacitor perpendicular to a gravitational field. The predictions could be verified by future laboratory experiments that could contribute on our understanding of the gravitational properties of anti-matter.

Ces travaux de thèse s'inscrivent à la frontière entre l'utilisation de l'interférométrie atomique pour tester un principe fondamental de physique, le principe d'équivalence faible, et le transfert des technologies développées dans ce but vers des applications industrielles, en particulier la navigation inertielle, à travers une collaboration avec l'entreprise iXBlue au sein d'un laboratoire commun (iXAtom) où nous avons travaillé à l'hybridation d'une centrale inertielle avec un accéléromètre atomique afin de corriger la dérive temporelle de la centrale.Afin de tester le prince d'équivalence faible, nous utilisons un interféromètre atomique double espèce (87Rb et 39K). Cette expérience est réalisée en laboratoire mais également en micropesanteur à bord de l'avion ZERO-G de Novespace. Cette particularité pose des contraintes sur les choix technologiques puisque le montage doit être robuste, compact et transportable. Notre système laser en est un bon exemple puisqu'il est basé des technologies télécom (1560 et 1534 nm) doublées en fréquence. Nous avons réalisé le premier test du principe d'équivalence en micropesanteur avec des atomes froids en 2015, ce qui représente une étape majeure vers la réalisation d'un instrument embarquable à bord d'un satellite.Le 39K est une espèce difficile à refroidir et à manipuler à cause de sa structure hyperfine étroite. Nous avons mis en place un refroidissement par mélasse grise pour cette espèce en ajoutant un laser résonnant avec la transition D1 du potassium. Nous avons également mis en place une préparation des atomes dans l'état non magnétique mF=0 efficace à 95%. Ces techniques ont amélioré le contraste de nos franges d'interférences d'un facteur 4 et nous a permis d'obtenir une sensibilité sur le paramètre d’Eötvös en laboratoire de 5.2x10-8 après 11500 s d'intégration<br>This thesis is at the boundary of the fundamental physics with the test of the weak equivalence principle (WEP) and the transfer of the technologies developed to industrial applications such inertial navigation. We began collaboration in a joint laboratory (iXAtom) with the iXBlue company where we worked on the hybridization of an inertial unit with a cold atom accelerometer.In order to test the WEP, we use a dual-species atom interferometer (87Rb and 39K). This experiment works in the laboratory but it is designed to perform onboard the Novespace ZERO-G plane. This specificity puts constraints on the design of the setup because it needs to be robust, compact and transportable. Our laser system is a good example because it is based on Telecom technologies (1560 and 1534 nm) frequency doubled. We realized the first test of the weak equivalence principle on microgravity with cold atoms in 2015, which is a major step toward a future spatial mission.The 39K is an atomic species hard to cool and manipulate because of its narrow hyperfine structure. We implemented an other cooling method, the gray molasses, by using a laser resonant to the potassium D1 transition. We built a new sequence to prepare the atoms in the mF= 0 state. This sequence is effective at 95%. These techniques improved the contrast of our interference fringes by a factor 4 which led to the obtention of a sensitivity on the Eötvös parameter in the laboratory of 5.2x10-8 after 11500 s of integration

Orientador: Edmundo Capelas de Oliveira<br>Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica<br>Made available in DSpace on 2018-08-15T07:12:57Z (GMT). No. of bitstreams: 1 Rodrigues_FabioGrangeiro_M.pdf: 2473878 bytes, checksum: edf9dfdf8d0b07b971df24b68798f67f (MD5) Previous issue date: 2010<br>Resumo: Neste trabalho é dada uma prova de equivalência entre diferentes formas de se escrever a lei de Faraday. a forma integral e a diferencial. Nosso objetivo é esclarecer alguns pontos relevantes da prova dessas equivalências que são normalmente apresentadas nos livros textos de Física apenas para casos muito particulares. Aqui apresentamos a derivação das ditas equivalências para uma situação geral. Incluímos também as ferramentas matemáticas necessárias para o tratamento rigoroso do nosso problema<br>Abstract: In this work we give a rigorous proof of the equivalence of some different forms of Faraday's law of induction clarifying some misconceptions on the subject and emphasizing that many derivations of this law appearing in textbooks and papers are only valid under very special circunstances and not satisfactory under a mathematical point of view. We include also the mathematical apparatus necessary for a rigorous presentation of our subject<br>Mestrado<br>Fisica-Matematica<br>Mestre em Matemática Universitária

In this thesis, design and analyses of honeycomb structures are investigated. Primary goal is to develop an equivalent orthotropic material model that is a good substitute for the actual honeycomb core. By replacing the actual honeycomb structure with the orthotropic model, during the finite element analyses, substantial advantages can be obtained with regard to ease of modeling and model modification, solution time and hardware resources . To figure out the best equivalent model among the approximate analytical models that can be found in the literature, a comparison is made. First sandwich beams with four different honeycomb cores are modeled in detail and these are accepted as reference models. Then a set of equivalent models with the same dimensions is generated. The material properties of the equivalent models are taken from different studies performed in the literature. Both models are analyzed under the same loading and the boundary conditions. In finite element analyses, ANSYS finite element program is used. The results are compared to find out the best performing equivalent model. After three major analyses loops, decision on the equivalent model is made. The differences between the total reaction forces calculated by the equivalent model and the actual honeycomb model are all found to be within 10%. The equivalent model gives stress results at the macro-scale, and the local stresses and the strains can not be determined. Therefore it is deemed that for stress analysis, equivalent model can be used during the preliminary design phase. However, the equivalent model can be used reliably for deflection analysis, modal analysis, stiffness determination and aero-elastic analysis.

Unidad de práctica para optar al título de Químico Farmacéutico<br>Autor no autoriza el acceso a texto completo de su documento<br>Para que un paciente pueda tener acceso a un medicamento, antes de estar a su disposición en farmacias o centros hospitalarios, éste debe haber sido registrado en nuestro país. El registro de productos farmacéuticos se lleva a cabo mediante un proceso que consiste en una serie de evaluaciones realizadas por el Instituto de Salud Pública (ISP), para asegurar que el medicamento sometido al trámite de registro sanitario cumpla los parámetros necesarios para su aprobación. Todo este proceso se lleva a cabo una vez que el futuro titular del registro (Laboratorio farmacéutico, Droguería, etc.), interesado en solicitar su aprobación, hace entrega de todos los antecedentes solicitados por la autoridad sanitaria. El ISP realiza la revisión de los antecedentes, en un proceso separado por etapas según el área documental a analizar, el tipo de registro sanitario a someter y el producto farmacéutico a evaluar. Finalmente, y luego de haber revisado toda la documentación requerida, la autoridad entrega la resolución aprobatoria o “inscríbase” al titular que solicitó el registro, con lo cual se da por finalizado y aprobado el trámite del registro sanitario. Con el propósito de mantener los estándares de calidad de los productos farmacéuticos, es necesario realizar modificaciones a estos, ya sea en su composición, indicaciones, y la información que contienen en sus rótulos y folletos de información al paciente. Todas estas modificaciones al registro sanitario deben ser visadas por la autoridad regulatoria. En el marco de generar la aprobación de un nuevo registro sanitario, el objetivo principal de este trabajo es conocer e interiorizarse en el proceso de registro de productos farmacéuticos, mediante la creación de un protocolo documental de evaluación, el cual permite revisar si el dossier del producto cuenta con los requerimientos necesarios para ser sometido al trámite de registro, y del mismo modo también permite ordenar y estructurar la documentación de forma sencilla y rápida. Así, la información estará organizada y preparada para ser sometida a la plataforma Gicona, para iniciar el proceso de registro de productos farmacéuticos. El resultado del trabajo realizado, indica que los plazos de entrega de la documentación por parte de los proveedores fueron menores mediante la utilización del protocolo, el cual es de utilidad en el momento de evaluar si el dossier del producto farmacéutico a evaluar, cumple con los requerimientos que solicita el ISP. También se observó la disminución del plazo para someter al trámite de registro de nuevos productos farmacéuticos, por el hecho de contar con la documentación de forma ordenada y clasificada con anterioridad

The article sets out that argentinean municipalities are legally banned from raising taxes, but are allowed to levy user charges for specific services. Nevertheless, such limitation is overlooked by the municipalities by means of introducing the “ability top ay” principle within the structure of the taxable base of said user charges. The author concludes that such mechanism distorts the user charge, altering its essence, with the result of transforming it into a mere tax, with the resulting violation of the current legislation.The author critically reviews argentinean case law that has given grounds to such a fiscal deviation and –in order to make his point- compares it with jurisprudence registered on this issue by the Supreme Courts of Peru, Brazil and Uruguay. Such comparison evidences that, if argentinean courts were to apply the criteria said of those Supreme Courts, almost every user charge in Argentina would have to be declared unconstitutional.<br>El artículo expone que los municipios argentinos están legalmente vedados de cobrar impuestos, viendo limitado su poder tributario al cobro de tasas. Sin embargo, en la práctica eluden esa prohibición mediante la maniobra de introducir en su base imponible criterios puros de capacidad contributiva (vgr. el monto de ventas), con total prescindencia del costo de los servicios retribuidos.El autor reseña críticamente la jurisprudencia de los tribunales argentinos, los cuales han convalidado el uso del principio de capacidad contributiva en materia de tasas. También efectúa una comparación con el tratamiento que esta cuestión ha tenido en los máximos tribunales de Perú, Brasil y Uruguay. Dicha comparación deja en evidencia que, de aplicarse en Argentina los criterios uniformemente sostenidos por los tribunales de estos tres países, una parte sustancial de las tasas hoy vigentes en este último país debería ser declarada inconstitucional.

Nonlinear response history analysis is accepted as the most accurate analytical tool for seismic response determination. However, accurate estimation of displacement responses using conceptually simple, approximate analysis procedures is preferable, since there are shortcomings in the application of nonlinear response history analysis resulting from its complexity. An equivalent linearization procedure, which utilizes the familiar response spectrum analysis as the analysis tool and benefits from the capacity principles, is developed in this thesis study as an approximate method for predicting the inelastic seismic displacement response of MDOF systems under earthquake excitations. The procedure mainly consists of the construction of an equivalent linear system by reducing the stiffness of structural members which are expected to respond in the inelastic range. Different from similar studies in literature, equivalent damping is not explicitly employed in this study. Instead, predetermined spectral displacement demands are utilized in each mode of the equivalent linear system for the determination of global displacement demands. Response predictions of the equivalent linearization procedure are comparatively evaluated by using the benchmark nonlinear response history analysis results and other approximate methods including conventional pushover analysis and modal pushover analysis (MPA). It is observed that the proposed procedure results in similar accuracy with approximate methods which employ nonlinear analysis. Considering the conceptual simplicity of the procedure and the conventional analysis tools used in its application, presented equivalent linearization procedure can be suggested as a practically applicable method for the prediction of inelastic seismic displacement response parameters with sufficient accuracy.

L’expérience I.C.E a pour objectif de tester le principe d’équivalence faible (WEP) à la base de la théorie de la relativité générale d’Einstein et postulant l’équivalence entre masse inertielle et masse grave. Si ce principe a toujours été vérifié jusqu’à aujourd’hui, il est d’un intérêt fondamental pour la physique moderne de poursuivre les mesures avec une précision accrue. En effet, de nouvelles théories d’unification de la mécanique quantique et de la relativité générale prévoient une violation de ce principe. Pour réaliser un test du WEP, il suffit de comparer les accélérations de deux objets en chute libre dans un même champ de gravitation, et c’est ce que réalise l’expérience I.C.E à l’échelle quantique (à la différence de la mission spatiale Microscope qui à ce jour a pu vérifier le WEP avec des objets macroscopiques avec une sensibilité sur le paramètre de 2.10−14). Ainsi, l’expérience consiste à réaliser, par une méthode interférométrique, la mesure de l’accélération de deux espèces atomiques (87Rb et 39K) de masses et de compositions différentes, en chute libre dans une enceinte à vide. La sensibilité de la mesure des effets inertiels auxquels les atomes sont sensibles (accélérations et rotations) est d’autant plus grande que la durée de chute libre des atomes est élevée et que la température des nuages est faible. Or, sur Terre au laboratoire, les atomes finissent par tomber au fond de l’enceinte les contenant sous l’effet de la gravité, ce qui limite grandement la sensibilité de la mesure. C’est pourquoi il est intéressant de placer l’expérience dans un environnement de micropesanteur dans lequel les atomes restent au centre de la chambre à vide afin d’atteindre des temps d’interrogation beaucoup plus longs. A ce titre, l’expérience est embarquée jusqu’à plusieurs fois par an, à bord de l’avion Zéro-g de la société Novespace. Les durées de micropesanteur proposées permettent d’atteindre des temps d’interrogation théoriques de l’ordre de la seconde ce qui doit porter le niveau de sensibilité à 10−11. Cependant, nous sommes aujourd’hui très fortement limités par le niveau élevé de vibrations et de rotations de l’avion : la perte de contraste des franges d’interférence engendrée ainsi que le bruit de phase introduit, ne nous permettent pas de dépasser des temps d’interrogation de 5 ms en 0 g. En parallèle, le laboratoire s’est récemment doté d’un simulateur de microgravité sur lequel est montée l’expérience, donnant accès à des temps d’interrogation de plus de 200 ms avec des trajectoires paraboliques d’une très bonne répétabilité (de l’ordre de 3 mg). La cohérence d’une source atomique étant directement reliée à sa température, l’utilisation de nuages ultra-froids est d’un grand intérêt pour améliorer le contraste des franges d’interférence, d’autant plus pour les longs temps d’interrogation visés. Le présent manuscrit synthétise les travaux ayant permis de produire le tout premier condensat de Bose-Einstein (la source atomique ultime) de 87Rb en microgravité par une méthode tout optique, et ce, de manière répétable toutes les 13,5 secondes. Nous démontrons l’efficacité de note méthode de chargement du piège dipolaire basée sur l’association d’un refroidissement par mélasse grise et d’une modulation spatiale des faisceaux dipolaires. Ces résultats ouvrent la voie vers de futures mesures interférométriques très sensibles à grand facteur d’échelle<br>The I.C.E experiment aims at testing the weak equivalence principle (WEP) underlying Einstein’s theory of general relativity and which postulates the equivalence between inertial mass and gravitationnal mass. If this principle has always been verified until today, it is of fundamental interest for physics to continue the measurements with greater precision. Indeed, new unifying theories of quantum mechanics and general relativity predict a violation of this principle. To carry out a test of the WEP, it suffices to compare the accelerations of two objects in free fall in the same gravitationnal field. This is what the I.C.E experiment, on the quantum scale, achieves (unlike the spatial Microscope mission, which to date has been able to verify the principle of equivalence with macroscopic objects with a sensitivity on of 2.10−14). Thus, the experiment consists in performing, by an interferometric method, the measurement of the acceleration of two atomic species (87Rb and 39K) of different mass and composition in free fall in a vacuum chamber. The measurement sensitivity of the inertial effects to which the atoms are sensitive (accelerations and rotations) is all the greater as the free fall time of the atoms is high and their temperature is low. But on Earth, in the laboratory, the atoms eventually fall to the bottom of the vacuum chamber containing them under the effect of gravity, which greatly limits the measurement sensitivity achievable. This is why it is interesting to place the experiment in a microgravity environment in which the atoms stay in the center of the vacuum chamber in order to reach much longer interrogation times. As such, several times a year, the experiment is put aboard the aircraft Zero-g of the Novespace company. The available microgravity durations make it possible to reach theoretical interrogation times of the order of one second, which should raise the sensitivity level to 10−11. However, we are today very strongly limited by the high level of vibrations of the aircraft as well as its rotations : the loss of contrast of the interference fringes and the phase noise caused, do not allow us to exceed 5 ms of interrogation times in 0 g. Since the coherence of an atomic source is directly related to its temperature, the use of ultra-cold clouds is of great interest to improve the contrast of the interference fringes, especially for the long interrogation times targeted. In parallel, the laboratory is now equipped with a microgravity simulator on which is mounted the experiment, giving access to interrogation times of more than 250 ms with parabolic trajectories of a very good repeatability (of the order of 3 mg). This manuscript synthesizes the work that produced the very first 87Rb Bose-Einstein condensate in microgravity by all-optical methods, with a repetition rate of 13,5 seconds. We demonstrate the efficiency of our dipole trap loading method based on the association of a grey molasses cooling and a spatial modulation of the dipole beams. These results pave the way for future highly sensitive interferometric measurements with a large scale factor

Dans la problématique émergente des expériences visant à tester le Principe d'Équivalence à l'aide de capteurs inertiels à atomes froids, cette thèse porte sur la réalisation et la caractérisation d'un interféromètre atomique double espèce simultané (⁸⁷Rb et ⁸⁵Rb) qui permet l'obtention d'une mesure extrêmement sensible de l'accélération différentielle. L'interféromètre, de type Mach-Zehnder, repose sur la manipulation simultanée des ondes de matière atomiques à l'aide de transitions Raman stimulées. Le système laser est basé sur le doublage en fréquence d'une unique source laser à 1560 nm. L'ensemble des fréquences lasers requises pour la manipulation des deux isotopes (piégeage, refroidissement, sélection, interférométrie et détection) sont générées par modulation en phase de cette source. Une modélisation détaillée des réponses inertielles de l'interféromètre ainsi que l'analyse d'une méthode d'extraction de la phase différentielle à partir du signal elliptique ont été menées. La mesure de l'accélération différentielle a conduit à un test atomique du Principe d'Équivalence Faible de η(⁸⁷Rb,85Rb) = (1.3 ± 3.2) × 10⁻⁷, à l'état de l'art. L'aspect simultané de la mesure a permis de mettre en évidence la réjection du bruit de vibration par effet de mode commun pour la première fois avec deux espèces différentes, le facteur de réjection étant aujourd'hui de 50 000. Les performances actuelles de l'instrument sur la mesure d'accélération différentielle montrent une sensibilité de 1.23×10⁻⁷g/√Hz et une résolution de 2×10⁻⁹g pour des temps d'intégration inférieurs à quelques heures. Pour finir, des modes de fonctionnement innovants d'interféromètres atomiques double espèce pour la mesure d'accélération embarquée sont explorés<br>In the emerging issue of testing the Equivalence Principle with cold atom inertial sensors, this thesis focuses on the realization and the characterization of a simultaneous dual-species atom interferometer (⁸⁷Rb &amp; ⁸⁵Rb) which allows to measure the differential acceleration in an extremely sensitive way. The Mach-Zehnder type atom interferometer relies on the simultaneous handling of atomic wave-packets with stimulated Raman transitions. The laser system is based on the frequency doubling of a single laser source at 1560 nm. All the required laser frequencies for handling both isotopes (trapping, cooling, selection, interferometry and detection) are generated by phase modulating this source. A detailed modeling of the interferometer's inertial responses and an analysis of a method to extract the differential phase were carried out. The differential acceleration measurement led to an atom based test of the Weak Equivalence Principle of η(⁸⁷Rb,85Rb) = (1.3 ± 3.2)×10⁻⁷, at the state-of-the-art. The simultaneous aspect of the experiment allowed to highlight for the first time common mode vibration noise rejection with two different atomic species, a rejection factor of 50 000 being currently achieved. The current performance of the instrument exhibits a sensitivity on the differential acceleration of 1.23 × 10⁻⁷g/√Hz and a resolution of 2 × 10⁻⁹g for integration times lower than few hours. Finally, innovative operating modes of dual-species atom interferometers for on-board acceleration measurements are explored

The equivalence principle has proven to be central to theories of gravity, with General Relativity being the simplest and most elegant theory to embody the principle. Most alternative theories of gravity struggle to satisfy the principle and still be distinct from GR. Extensions of cosmological and quantum theories question the irrefutably of the equivalence at every scale. The possibility of an equivalence principle violation at galactic scales would be an exciting prospect. In this thesis, we will carefully examine the equivalence principle through the study of chameleon scalar-tensor theories, this will include solutions for hypothetical stars known as boson stars. Such theories find varied application, especially in cosmology, where they model dark energy and inflation. The AWE hypothesis, is an instance of this. It is a nonuniversally coupled model in which violations of the equivalence principle on galactic scales may be apparent. We investigate spherically symmetric and static solutions within the framework of this theory. The constraints obtained from galactic rotation curves results in values of the couplings that show no significant violation of the equivalence principle or values consistent with a theory of dark energy

Dans ce mémoire, nous présentons l'étude d'un senseur inertiel à ondes de matière embarqué dans un avion effectuant des vols paraboliques.Une source laser bi-fréquence robuste et compacte permettant de refroidir et d'interroger simultanément des atomes de 87Rb et 39K a été développée. Elle est basée sur des lasers télécom asservis sur un peigne de fréquences optique et doublés en fréquence. L'utilisation de composants optiques fibrés permet de rendre le système intrinsèquement résistant aux vibrations et aux fluctuations thermiques. Le dispositif a été validé en vol par l'obtention d'un double piège magnéto-optique.Nous avons utilisé la source laser pour faire fonctionner un interféromètre à atomes froids de 87Rb dans l'avion. Un accéléromètre mécanique auxiliaire permet d'augmenter la dynamique du capteur atomique et d'enregistrer des franges d'interférences malgré le niveau élevé des fluctuations d'accélération. Le senseur hybride ainsi réalisé a une résolution de 4.10-3 m.s-2.Hz-1/2, environ 100 fois plus faible que le niveau des vibrations dans l'avion.Dans la perspective de réaliser un test du principe d'équivalence en microgravité avec des atomes froids, nous étudions enfin de manière théorique le fonctionnement d'un interféromètre différentiel et nous intéressons à l'influence de certains effets systématiques.

Orientadores: Marcelo Moraes Guzzo e Pedro Cunha de Holanda.<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin.<br>Made available in DSpace on 2018-08-12T12:12:58Z (GMT). No. of bitstreams: 1 Valdiviesso_GustavodoAmaral_D.pdf: 2795816 bytes, checksum: 93e348ecdbd1623e5c6992f732c0af14 (MD5) Previous issue date: 2008<br>Resumo: Neste trabalho, estudamos o modelo para violação do princípio da equivalência (VEP) em neutrinos solares e de reatores. Este modelo já foi considerado como uma solução promissora ao problema do neutrino solar (PNS), mas foi descartado por não ser capaz de explicar os dados referentes a neutrinos solares e anti-neutrinos de reatores, com um mesmo conjunto de parâmetros físicos. O modelo de mistura massa-sabor em conjunto com o efeito MSW tem se mostrado como único capaz de explicar todos os dados disponíveis na área. Novos limites para a violação do princípio da equivalência podem ser obtidos para neutrinos solares e de reatores, considerando agora um modelo combinado entre a hipótese de mistura massa-sabor e o modelo de VEP. Nossa análise mostra uma tendência favorável a duas soluções conjuntas onde os efeitos de VEP praticamente não alteram neutrinos solares: uma em que a escala de massa dos neutrinos de reatores permanece inalterada e outra onde tal escala cai levemente, se aproximando do resultado para o ajuste somente dos dados solares. A solução conjunta aponta para o seguinte conjunto de parâmetros: | f D g | = 9,12 + 0,97 -0,78 × 10-21, tan 2 q = 0,478 +0,040-0,038 e D m2 = 6,63 ± 0,31 × 10-5 eV 2 (77,7% C.L.) e | f D g | = 1,91+0,84 -0,61× 10-21, tan 2 q = 0,478+0,040-0,038 e D m2 = 7,73 +0,17-0,20 × 10-5 eV 2 (77,7% C.L.). Ambas soluções melhoram o nível de confiança com relação à solução MSW (tan2 q = 0,462+0,043-0,036 e D m2 = 7,75+0,16-0,12 x 10-5 eV2, 73,1% C.L.) Um limite superior para VEP foi obtido como sendo |f D g | £ 1,3 ×10-20(3 s ) sobre a solução MSW.<br>Abstract: In this work, we studied the model for the violation of the equivalence principle (VEP) on solar and reactor neutrinos. This model was already considered as a promising solution to the solar neutrino problem (SNP), but was abandoned because it wasn¿t able to explain all the data with a single set of physical parameters. The mass- avor mixing model, together with the MSW effect has been shown to as the only model able do explain all the available data. New limits for the VEP are obtained for solar and reactor neutrinos, considering a combined model, with the mass- avor mixing hypothesis and the VEP model. Our analysis shows two solutions were the VEP effects practically don¿t change the solar sector: one where the mass scale of the reactor sector remains the same and another one where this scale falls slightly, becoming closer to the solar solution. The combined solution points to the following set of parameters: a "higher vep" | f D g | = 9,12 + 0,97 -0,78 × 10-21, tan 2 q = 0,478 +0,040-0,038 and D m2 = 6,63 ± 0,31 × 10-5 eV 2 (77,7% C.L.) and a "lower vep" | f D g | = 1,91+0,84 -0,61× 10-21, tan 2 q = 0,478+0,040-0,038 e D m2 = 7,73 +0,17-0,20 × 10-5 eV 2 (77,7% C.L.). Both solutions increases the confidence level when compared with the MSW solution (tan2 q = 0,462+0,043-0,036 and D m2 = 7,75+0,16-0,12 x 10-5 eV 2, 73,1% C.L.) A superior limit has also been obtained for VEP: |f D g | £ 1,3 ×10-20(3 s ) over the MSW solution.<br>Doutorado<br>Física das Particulas Elementares e Campos<br>Doutor em Ciências

Made available in DSpace on 2016-12-12T20:25:13Z (GMT). No. of bitstreams: 1 Thais Clara da Costa Haveroth.pdf: 3726370 bytes, checksum: 204349100247f52ea6bf4916ec49a0ab (MD5) Previous issue date: 2015-10-26<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Dentre a vasta gama de polímeros estruturais atualmente disponíveis no mercado, este trabalho está particularmente voltado ao estudo do polietileno de alta densidade. Embora este material já tenha sido investigado por diversos autores, seu típico comportamento viscoelástico não-linear apresenta dificuldades na modelagem. Visando uma nova contribuição, este trabalho propõe a descrição de tal comportamento utilizando uma abordagem baseada em derivadas fracionários. Esta formulação produz equações constitutivas fracionais que resultam em boas propriedades de ajuste de curvas com menos parâmetros a serem identificados que nos métodos tradicionais. Neste sentido, os resultados experimentais de fluência para o polietileno de alta densidade, avaliados em diferentes níveis de tensão, são ajustados por este esquema. Para estimar a deformação à níveis de tensão que não tenham sido medidos experimentalmente, o princípio da equivalência tensão-tempo é utilizado e os resultados são comparados com aqueles apresentados por uma interpolação linear dos parâmetros. Além disso, o princípio da superposição modificado é aplicado para predizer a comportamento de materiais sujeitos a níveis de tensão que mudam abruptamente ao longo do tempo. Embora a abordagem fracionária simplifique o problema de otimização inversa subjacente, é observado um grande aumento no esforço computacional. Assim, alguns algoritmos que objetivam economia computacional, são estudados. Conclui-se que, quando acurária é necessária ou quando um modelo de séries Prony requer um número muito grande de parâmetros, a abordagem fracionária pode ser uma opção interessante.<br>Among the wide range of structural polymers currently available in the market, this work is concerned particularly with high density polyethylene. The typical nonlinear viscoelastic behavior presented by this material is not trivial to model, and has already been investigated by many authors in the past. Aiming at a further contribution, this work proposes modeling this material behavior using an approach based on fractional derivatives. This formulation produces fractional constitutive equations that result in good curve-fitting properties with less parameters to be identified when compared to traditional methods. In this regard, experimental creep results of high density polyethylene evaluated at different stress levels are fitted by this scheme. To estimate creep at stress levels that have not been measured experimentally, the time-stress equivalence principle is used and the results are compared with those presented by a linear interpolation of the parameters. Furthermore, the modified superposition principle is applied to predict the strain for materials subject to stress levels which change abruptly from time to time. Some comparative results are presented showing that the fractional approach proposed in this work leads to better results in relation to traditional formulations described in the literature. Although the fractional approach simplifies the underlying inverse optimization problem, a major increase in computational effort is observed. Hence, some algorithms that show computational cost reduction, are studied. It is concluded that when high accuracy is mandatory or when a Prony series model requires a very large number of parameters, the fractional approach may be an interesting option.

Lors de ces vingt dernières années, de nouvelles techniques de refroidissement et de manipulation des atomes ont permis le développement de senseurs inertiels basés sur l’interférométrie atomique. Le projet ICE est un interféromètre atomique double espèce qui a pour objectif de tester le principe d’équivalence faible. Afin d’augmenter la sensibilité de l’instrument, l’expérience est réalisée en micro-gravité lors de vols paraboliques à borde l’Airbus A300 zero-g de Novespace. L’interféromètre est composé de deux espèces atomiques (87Rb et 39K) ayant des transitions atomiques très proches (780 et 767nm). Ces longueurs d’ondes sont générées par une source laser bi-fréquence ultra-stable. Issue des technologies telecom et ensuite doublées en fréquence, elle est capable de résister aux contraintes des vols paraboliques. Précédemment, des mesures d’accélérations furent réalisées par un interféromètre Rubidiumen 1g et 0g en vol. Récemment, à l’aide d’un nouveau dispositif expérimental reposant sur une nouvelle enceinte à vide en titane, nous avons réalisé un des premiers accéléromètres Potassium. Cet atome présente en effet certaines difficultés à refroidir et à manipuler et demande un excellent contrôle des différents paramètres expérimentaux.Je présente ainsi dans ce manuscrit, les résultats obtenus avec le Rubidium et le Potassium sur le nouveau dispositif expérimental, et les récents progrès réalisés en vue d’un accéléromètre double espèce Rb/K<br>During the last two decades, new techniques to cool and manipulate atoms has enabled the development of inertial sensors based on atom interferometry. The ICE project aims to verify the weak equivalence principle (WEP) using a compact and transportable dual-species atom interferometer. To make precise tests of the WEP, this experiment is performed in a micro-gravity environment during parabolic flights onboard the Novespace zero-g aircraft. The interferometer is composed of two atomic species (87Rb et 39K) with similar transition wavelengths (780 nm and 767 nm), which are derived from frequency-doubled telecom lasers. This ultra-stable laser source is able to withst and the parabolic flight and their rough conditions.In previous work, we have demonstrated measurements from a cold rubidium interferometer during the 1g and 0g phases during flights. Recently, we manage to carry out one of the first gravimeter with 39K in a new titanium vacuum system. This is a huge achievement because this atom is hard to cool down and to manipulate. I will present in this thesis, the results with Rubidium and Potassium on the newset-up, I we will report on recent progress toward a double species 87Rb/39K interferometer

Quantensensoren, wie Atominterferometer und Atomuhren werden zu hochpräzisen und akkuraten Messungen von Inertialkräften und der Zeit benutzt und sind hervorragend dazu geeignet fundamentale Fragestellungen der Physik anzugehen und die Aussagen der allgemeinen Relativitätstheorie zu testen. Die Empfindlichkeit von Atominterferometern skaliert quadratisch mit der freien Entwicklungszeit und die Verwendung von Quantensensoren im Weltraum ist prädestiniert die Genauigkeit von Tests des Äquivalenzprinzips um mehrere Größenordnungen zu verbessern. Zusätzlich, werden präzise und akkurate Sensoren für Inertialkräfte, im Bereich der Navigation oder Geodäsie benutzt wo mobile auf Atominterferometrie basierende Geräte noch selten sind. Diese Arbeit trägt zur Entwicklung von hochempfindlichen und stabilen mobilen Quantensensoren bei. Im Rahmen dieser Doktorarbeit wurden drei mobile Vergleichsmessungen der Erdbeschleunigung mit dem Atominterferometer GAIN an verschiedenen geographischen Orten durchgeführt. Die demonstrierte Stabilität von 5*10^-11 g nach 10^5 s übertrifft die Stabilität von klassischen Gravimetern. Mit dem Ziel von Weltraumgestützten Atominterferometern wurde ein kompaktes Lasersystem für den Betrieb von Atominterferometrie mit Rubidium Bose-Einstein Kondensaten auf Höhenforschungsraketen entworfen, qualifiziert und in Betrieb genommen. Zusätzlich wurden drei Nutzlasten für dein Einsatz auf Höhenforschungsraketen realisiert um die Reife der notwenigen Subsysteme zu zeigen. Dopplerfreie Laserspektroskopie an Rubidium und Kalium wurde verwendet um eine optische Frequenzreferenz zu realisieren und während der Flüge wurde mit einem Frequenzkamm zu vergleichen. Diese Messung stellt einen ersten Test der Lokalen Lorenz Invarianz im Weltraum dar. Diese Aktivitäten ebnen den Weg für den zukünftigen Einsatz von Quantensensoren im Weltraum die noch nie dagewesene Tests der fundamentalen Physik, Weltraumgeodäsie oder sogar Gravitationswellen ermöglichen.<br>Quantum sensors, such as atom interferometers and atomic clocks are used for high precision and accurate measurements of inertial forces and time and are therefore ideally suited to address fundamental questions in physics and to test the predictions of general relativity. The sensitivity of atom interferometers scales quadratically with the free evolution time and the use of quantum sensors in space is predestined to improve the accuracy of such tests by several orders of magnitude. Additionally, precise and accurate sensors for inertial forces are required in the field of navigation or geodesy where mobile devices based on atom interferometry are still rare. This work contributes to the development of highly sensitive and stable mobile quantum sensors. In the course of this thesis, three measurement comparisons of the gravitational acceleration with the mobile atom interferometer GAIN were performed at different geographic locations. The demonstrated stability of 5*10^-11 g after 10^5 s surpasses the one reached by classical gravimeters. With the goal of space-born atom interferometry, a compact laser system for operation of atom interferometry with Bose-Einstein condensates of rubidium on a sounding rocket was designed, qualified and put in operation. Additionally, three sounding rocket payloads were realized to show the technological maturity of the necessary subsystems. Doppler-free laser spectroscopy of rubidium and potassium was used to realize an optical frequency reference that was compared during the flights to an atomic microwave standard via a frequency comb. This measurement represents the first test of the Local Position Invariance in space. These activities pave the way for future deployment of quantum sensors in space enabling unprecedented tests of fundamental physics, space geodesy or even gravitational wave detection.

cette thèse porte sur l'étude d'un accéléromètre à ondes de matière fonctionnant à bord d'un avion effectuant des vols paraboliques et permettant des expériences en micro-gravité (0-g). Un interféromètre à atomes de 87Rb refroidis par laser, et dont les états quantiques sont manipulés à l'aide de transitions Raman stimulées, constitue l'élément physique du capteur. Lors de la conception du dispositif expérimental, un effort particulier a été apporté au choix d'une source laser transportable, stable, et robuste. Nous démontrons pour la première fois le fonctionnement aéroporté d'un senseur inertiel à ondes de matière, à la fois en 0-g et durant les phases de gravité des vols (1-g). Nous proposons une technique combinant le signal de l'interféromètre à celui d'accéléromètres mécaniques auxiliaires pour effectuer des mesures au dela de la dynamique intrinsèque du capteur atomique. Nous expliquons comment bénéficier du haut niveau de sensibilité de l'interféromètre dans l'avion, et indiquons des voies d'améliorations significatives de notre dispositif pour le futur. En 0-g, nous montrons une amélioration de la sensibilité de l'accéléromètre jusque 2 x 10-4 m.s-2 à une seconde, et étudions une réjection des vibrations de l'avion à l'aide d'un interféromètre à quatre impulsions Raman. L'objectif de notre projet consiste en un test du principe d'universalité de la chute libre avec un double accéléromètre à atomes de 87Rb et de 39K. Notre système laser double-espèce emploie des composants optiques fibrés aux longueurs d'onde de 1.56 et 1.54 μm, ainsi qu'un doublage de fréquence pour obtenir la lumière utile à 780 et 767 nm pour le refroidissement et la manipulation des deux atomes. Nous étudions théoriquement la sensibilité d'une mesure de leur différence d'accélération en tenant compte des vibrations de l'avion, et précisons comment une résolution de l'ordre de 10-10 m.s-2 pourra être atteinte dans le futur avec notre expérience aéroportée.

Esta tese apresenta uma análise estatística detalhada dos dados de experimentos com neutrinos solares mais recentes, com duas diferentes soluções para oscilações de neutrinos, ambas caracterizadas por um grande comprimento de oscilação. A primeira baseada no mecanismo de oscilação padrão, ou seja, induzida por massa, sendo esta estudada nos casos de duas e três gerações e dentro do regime de quase-vácuo. E a segunda, uma exótica, que usa como mecanismo de oscilação uma possível violação do princípio de equivalência, que foi analisada somente para o caso de duas gerações, sendo este discutido para transições entre neutrinos ativos, e entre neutrinos ativos e estéreis. Nossos resultados mostraram que ambas soluções são consistentes com os dados de neutrinos solares e, também, no caso específico do quase-vácuo, observamos que a hipótese de três gerações ficou desfavorecida.<br>This thesis presents a well detailed statistical analysis using the recent data from solar neutrino experiments. This analysis was done in the framework of two different solutions of neutrino oscillations, both characterized by a long oscillation wavelength. The first was based on the standard mass induced oscillation mechanism, here we worked in the scheme of two and three neutrino generations within the quasivacuum regime. The second was an exotic mechanism, where the neutrino oscillation is due to a possible breakdown of the equivalence principle, this alternative was analyzed only for two neutrino generations, in the cases for the conversion among active neutrino and active to sterile neutrino. Our results show a good agreement between the solar neutrino data and both solutions, also in the specific case of quasivacuum, we found that the hypothesis for the three neutrino generation is disfavored.

Made available in DSpace on 2015-05-15T11:46:15Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 346206 bytes, checksum: 8088f6a0baa8eb637021343c390a391a (MD5) Previous issue date: 2009-12-02<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>In this work we present a recent result, due to D. Pellegrino and E. V. Teixeira, that characterizes the continuous linear operators between lpspaces which attain their norms. To this end, we Örstly explore some topics from the Banach space theory, such as Banachís Theorem for basis, Bessaga-Pe &#771;czynski Selection Principle and Pittís Theorem.<br>Neste trabalho apresentaremos um recente resultado, devido a D. Pellegrino e E. V. Teixeira, que caracteriza os operadores lineares contínuos entre espaços lp que atingem a norma. Para tanto, vamos desenvolver alguns tópicos da teoria de bases em espaços de Banach e também mostrar alguns importantes resultados da teoria de espaços de Banach, tais como o Teorema de Banach sobre bases, o Princípio de Seleção de Bessaga- Pe÷czy´nski e o Teorema de Pitt.

The main objective of this research is to model and analyse complex electromagnetic problems by means of a new hybridised computational technique combining the frequency domain Method of Moments (MoM), Finite-Difference Time-Domain (FDTD) method and a subgridded Finite-Difference Time-Domain (SGFDTD) method. This facilitates a significant advance in the ability to predict electromagnetic absorption in inhomogeneous, anisotropic and lossy dielectric materials irradiated by geometrically intricate sources. The Method of Moments modelling employed a two-dimensional electric surface patch integral formulation solved by independent linear basis function methods in the circumferential and axial directions of the antenna wires. A similar orthogonal basis function is used on the end surface and appropriate attachments with the wire surface are employed to satisfy the requirements of current continuity. The surface current distributions on structures which may include closely spaced parallel wires, such as dipoles, loops and helical antennas are computed. The results are found to be stable and showed good agreement with less comprehensive earlier work by others. The work also investigated the interaction between overhead high voltage transmission lines and underground utility pipelines using the FDTD technique for the whole structure, combined with a subgridding method at points of interest, particularly the pipeline. The induced fields above the pipeline are investigated and analysed. FDTD is based on the solution of Maxwell¿s equations in differential form. It is very useful for modelling complex, inhomogeneous structures. Problems arise when open-region geometries are modelled. However, the Perfectly Matched Layer (PML) concept has been employed to circumvent this difficulty. The establishment of edge elements has greatly improved the performance of this method and the computational burden due to huge numbers of time steps, in the order of tens of millions, has been eased to tens of thousands by employing quasi-static methods. This thesis also illustrates the principle of the equivalent surface boundary employed close to the antenna for MoM-FDTD-SGFDTD hybridisation. It depicts the advantage of using hybrid techniques due to their ability to analyse a system of multiple discrete regions by employing the principle of equivalent sources to excite the coupling surfaces. The method has been applied for modelling human body interaction with a short range RFID antenna to investigate and analyse the near field and far field radiation pattern for which the cumulative distribution function of antenna radiation efficiency is presented. The field distributions of the simulated structures show reasonable and stable results at 900 MHz. This method facilitates deeper investigation of the phenomena in the interaction between electromagnetic fields and human tissues.<br>Ministry of Higher Education Malaysia and Universiti Tun Hussein Onn Malaysia (UTHM)

Regroupés sous le vocable d’« instruments économiques » – ou instruments de marché (market-based instrument) –, les mécanismes de compensation écologique et de paiements pour services environnementaux se sont imposés comme des instruments incontournables des politiques de protection de la biodiversité et des écosystèmes. Articulés autour d’une pluralité de principes (principe pollueur-payeur, principe bénéficiaire-payeur, etc.) et de concepts (services écosystémiques, capital naturel, etc.) largement influencés par les approches économiques de la biodiversité et des écosystèmes, ces deux instruments caractérisent l’émergence d’une nouvelle approche des politiques environnementales. L’étude révèle la pluralité des liens juridiques qui unissent la compensation écologique et les paiements pour services environnementaux. Tantôt rapprochés, tantôt distingués, ces mécanismes s’imposent, in fine, comme les deux faces d’une même pièce. L’utilisation des paiements pour services environnementaux, à des fins de compensation écologique, apparaît toutefois comme une orientation préoccupante de nature à détourner cet instrument de son objet. En dépit de leurs vertus théoriques, l’efficacité des mécanismes de compensation écologique et de paiements pour services environnementaux pour la protection de la biodiversité se révèle discutable, justifiant un renforcement et une mise en cohérence de leur cadre juridique<br>Gathered under the term “economic instruments” – or market-base instruments -, mechanisms for ecological compensation and payments for environmental services have established themselves as the essential tool for the biodiversity and ecosystem protection policies. Built around a plurality of principles (polluter pays principle, beneficiary pays principle, etc.) and concepts (ecosystem services, natural capital, etc.) largely influenced by economical approaches of biodiversity and ecosystems, these two instruments characterize the oncoming of a new take on environmental policies. The study reveals the plurality of judicial links that unite ecological compensation and payments for environmental services. Sometimes close together, sometimes distinguishable, these mechanisms are, in fine, both sides of a same coin. The use of payments for environmental services, as ecological compensation, appears however as a preoccupying orientation, likely to deflect this instrument from its purpose. In spite of their theoretical virtues, the efficiency of ecological compensation mechanisms and payments for environmental services for the protection of biodiversity turns out to be questionable, justifying a reinforcement and more consistency in their legal framework

The main objective of this research is to model and analyse complex electromagnetic problems by means of a new hybridised computational technique combining the frequency domain Method of Moments (MoM), Finite-Difference Time-Domain (FDTD) method and a subgridded Finite-Difference Time-Domain (SGFDTD) method. This facilitates a significant advance in the ability to predict electromagnetic absorption in inhomogeneous, anisotropic and lossy dielectric materials irradiated by geometrically intricate sources. The Method of Moments modelling employed a two-dimensional electric surface patch integral formulation solved by independent linear basis function methods in the circumferential and axial directions of the antenna wires. A similar orthogonal basis function is used on the end surface and appropriate attachments with the wire surface are employed to satisfy the requirements of current continuity. The surface current distributions on structures which may include closely spaced parallel wires, such as dipoles, loops and helical antennas are computed. The results are found to be stable and showed good agreement with less comprehensive earlier work by others. The work also investigated the interaction between overhead high voltage transmission lines and underground utility pipelines using the FDTD technique for the whole structure, combined with a subgridding method at points of interest, particularly the pipeline. The induced fields above the pipeline are investigated and analysed. FDTD is based on the solution of Maxwell's equations in differential form. It is very useful for modelling complex, inhomogeneous structures. Problems arise when open-region geometries are modelled. However, the Perfectly Matched Layer (PML) concept has been employed to circumvent this difficulty. The establishment of edge elements has greatly improved the performance of this method and the computational burden due to huge numbers of time steps, in the order of tens of millions, has been eased to tens of thousands by employing quasi-static methods. This thesis also illustrates the principle of the equivalent surface boundary employed close to the antenna for MoM-FDTD-SGFDTD hybridisation. It depicts the advantage of using hybrid techniques due to their ability to analyse a system of multiple discrete regions by employing the principle of equivalent sources to excite the coupling surfaces. The method has been applied for modelling human body interaction with a short range RFID antenna to investigate and analyse the near field and far field radiation pattern for which the cumulative distribution function of antenna radiation efficiency is presented. The field distributions of the simulated structures show reasonable and stable results at 900 MHz. This method facilitates deeper investigation of the phenomena in the interaction between electromagnetic fields and human tissues.

Syftet med studien är att beskriva och problematisera hur rektorer verksamma inom år f-6 resonerar om satsningen på digitalisering utifrån begreppet likvärdighet. Åtta rektorer på olika skolor är intervjuade. Resultatet visade att rektorerna på olika sätt bedriver skolutveckling inom området digitalisering för att uppnå likvärdighet inom verksamheten. I resultatet framkommer dock skillnader i hur långt verksamheterna kommit både inom skolor och mellan skolor utifrån; digitalisering, digital kompetens och likvärdighet.  Rektorerna lyfter olika lokala orsaker till att verksamheternas digitala implementering kommit olika långt. En slutsats som går att dra efter resultat är vilka komplexa förutsättningar en rektor har att arbeta efter för att uppnå likvärdighet genom digitalisering. Rektorerna lyder under ett dualistiskt ledarskap, både från kommun och stat. Rektorerna är således klämda mellan yttre och inre ramar som påverkar verksamheten. I studiens resultat kommer detta till uttryck genom att samtliga rektorer upplever att de måste välja och prioritera olika skolutvecklingsområden. Det kan leda till att det uppstår en ojämlikhet inom området digitalisering.<br>The purpose of the study has been to describe and problematize how principals are perceiving equity in digitalization based on the concepts in K-6. Eight principals at different schools from the same municipality have been interviewed. The results show that principals use various methods to conduct school development of ​​digitalization in order to achieve equality within the school. Inparticular the results show that there are differences in how far the development of digitalization, digital skills and equivalence has reached both within schools and between schools. The principals have different points of focus in managing the digital implementation. One conclusion based on the analysis is the complex conditions a principal must work under to achieve equality through digitization. The principals are caught between leadership from the municipality and the state. This study shows that all principals must choose individually an area to develop within their school. This can lead to inequalities in the field of digitalization.

La compensation écologique, envisagée dans le respect de la séquence éviter-réduire-compenser les impacts, cherche à apporter des réponses à la crise actuelle d’érosion de la biodiversité. L’objectif de la thèse est de comprendre quels sont les enjeux organisationnels et institutionnels de la mise en œuvre du principe de compensation écologique pour les impacts sur les écosystèmes aquatiques marins et continentaux en Europe et aux Etats-Unis. La thèse mobilise le cadre théorique de l’économie néo-institutionnelle. Les organisations de type hiérarchique (compensation au cas par cas) ont pour principales limites d’avoir une efficacité écologique discutable et de ne pas permettre le suivi et le contrôle des mesures compensatoires ce qui conduit souvent à ce que la compensation ne soit pas ou peu mise en œuvre. Aux Etats-Unis, les banques de compensation consistent en une réponse anticipée et mutualisée aux dommages à l’environnement. Il s’agit d’une forme organisationnelle alternative hybride fortement régulée à mi-chemin entre la hiérarchie et le marché. Cependant, les acteurs ont des stratégies collectives et individuelles qui engendrent des négociations ayant des conséquences sur les enjeux de développement économique et de maintien des objectifs de conservation de la biodiversité. Le système des banques de compensation crée un double phénomène de redistribution des coûts de transaction et de diminution de ceux-ci mais il semble que l’évolution de l’ensemble du cadre d’application de la compensation écologique américain permet aujourd’hui une complémentarité institutionnelle entre ces deux formes organisationnelles plutôt qu’une disparition des formes hiérarchiques<br>Biodiversity offset, as the last step of the mitigation hierarchy (avoid/reduce/offset), aims to address the current biodiversity loss crisis. The main goal of this PhD, which relies on the new institutional economics approach as a theoretical framework, is to understand the organizational and institutional issues of implementing biodiversity offsets policies for impacts on continental and offshore wetlands in Europe and the United-States. Hierarchical organizations (i.e. permittee responsible mitigation) often lead to little to no implementation of biodiversity offsets because the ecological effectiveness of case-by-case compensatory measures is unproven and the monitoring and control of numerous measures are difficult. In the United-States, the mitigation banking system aims to compensate for multiple small impacts on wetlands by carrying out restoration projects on fewer but larger wetland areas in order to reach the goal of no net loss of biodiversity. This hybrid organizational form is highly regulated and therefore stands halfway between hierarchical and market organizations. However, actors have individual and collective strategies that generate negotiations with consequences on economic development and biodiversity conservation stakes. The mitigation banking system leads to a decrease of transaction costs and a change of the actors bearing them. It seems that the evolution of the whole framework of biodiversity offsets policy implementation in the United-States leans toward an institutional complementarity between these two organizational forms rather than a disappearance of hierarchical organizations

Захищено англійською мовою<br>Мета: вивчення актуальних підходів до теорії та практики художнього перекладу, їх застосування у практичній діяльності перекладачів художніх текстів та навчання таким прийомам здобувачів вищої освіти за спеціальністю «Переклад». Наукова проблема: на сьогодні спостерігається бурхливий розвиток перекладознавчої науки, пов’язаний з процесами глобалізації, активного розвитку міжкультурних зв’язків та діалогу культур в різних сферах діяльності людини. З огляду на це теорія та практика перекладу постійно стикається з новими проблемами й викликами та потребує актуалізації відповідно до сучасних реалій та вимог. Методологія дослідження: включає описовий та порівняльний методи, які використовувалися у ході теоретичного осмислення предмета дослідження; метод кількісного аналізу, контекстуальний аналіз та елементи компонентного аналізу, а також перекладацький аналіз, які застосовані у ході практичного дослідження питання культурологічного підходу до перекладу художніх текстів; а також метод моделювання, використаний у ході розробки вправ для навчання художньому перекладу студентів-перекладачів. Основні результати і висновки дослідження: Художнім текстам притаманні образність, естетика мовлення, експресія, зображувальність, відсутність регламентування вживання мовних засобів і способів їх поєднання, відсутність будь-якого нормування мови, суб’єктивізм відображення подій та реалій життя, фантазія як основа створення образів та відображення явищ дійсності. Переклад художнього тексту – це складний і багатогранний вид людської діяльності та творчості. Це не просто переклад творів художньої літератури та художніх текстів, однак також і трансформація тексту оригіналу засобами іншої мови, і взаємодія та взаємовплив двох культур – вихідної та цільової, до яких належать оригінальний текст та текст перекладу. На сьогодні актуальними напрямками дослідження перекладу художніх текстів стають питання використання принципів адекватності та еквівалентності художнього перекладу, а також явище «культурного перевороту» у сфері художнього перекладу, яке передбачає використання стратегій доместикації та форенізації культурно-маркованих елементів художнього тексту. У роботі здійснено аналіз перекладу англомовного художнього твору, який містить культурно-специфічну інформацію, який показав, що досить часто перекладач не справляється з відтворенням такої інформації у перекладі. Причинами невмотивованості замін при перекладі культурно-специфічних реалій та лакун, а також неправильного вибору перекладацької стратегії може бути недостатній рівень фонових знань перекладача, брак ефективних перекладацьких підходів до передачі культурних елементів тощо. У роботі досліджені методичні передумови, принципи та особливості навчання перекладу студентів ЗВО. Розглянуті основні етапи та складові навчання художнього перекладу, а також на основі цих даних розроблені вправи для навчання усного та письмового художнього перекладу майбутніх перекладачів. Теоретичне значення: систематизація теоретичних знань про художній стиль англійської мови та актуальні напрямки розвитку художнього перекладу; узагальнення методичних передумови навчання художньому перекладу студентів-перекладачів<br>Цель: изучение актуальных подходов к теории и практике художественного перевода, их применение в практической деятельности переводчиков художественных текстов и обучении таким приемам соискателей высшего образования по специальности «Перевод». Научная проблема: сегодня наблюдается бурное развитие переводческой науки, связанное с процессами глобализации, активного развития межкультурных связей и диалога культур в различных сферах деятельности человека. Учитывая это, теория и практика перевода постоянно сталкивается с новыми проблемами и вызовами и требует актуализации в соответствии с современными реалиями и требованиями. Методология исследования: включает описательный и сравнительный методы, которые использовались в ходе теоретического осмысления предмета исследования; метод количественного анализа, контекстуальный анализ и элементы компонентного анализа, а также переводческий анализ применены в ходе практического исследования вопроса культурологического подхода к переводу художественных текстов; метод моделирования использован в ходе разработки упражнений для обучения художественному переводу студентов-переводчиков. Основные результаты и выводы исследования: Художественным текстам присущи образность, эстетика речи, экспрессия, изобразительность, отсутствие регламентирования употребления языковых средств и способов их сочетания, отсутствие любого нормирования языка, субъективизм отображения событий и реалий жизни, фантазия как основа создания образов и отражение явлений действительности. Перевод художественного текста – это сложный и многогранный вид человеческой деятельности и творчества. Это не просто перевод произведений художественной литературы и художественных текстов, однако также и трансформация текста оригинала средствами другого языка, и взаимодействие и взаимовлияние двух культур – исходной и целевой, к которым относятся оригинальный текст и текст перевода. На сегодня актуальным направлениям исследования перевода художественных текстов становятся вопросы использования принципов адекватности и эквивалентности художественного перевода, а также явление «культурного переворота» в сфере художественного перевода, который предусматривает использование стратегий доместикации и форенизации культурно-маркированных элементов художественного текста. В работе проведен анализ перевода англоязычного художественного произведения, содержащий культурно-специфическую информацию, который показал, что достаточно часто переводчик не справляется с воспроизведением такой информации в переводе. Причинами немотивированности замен при переводе культурно-специфических реалий и лакун, а также неправильного выбора переводческой стратегии может быть недостаточный уровень фоновых знаний переводчика, отсутствие эффективных переводческих подходов к передаче культурных элементов и т. п. В работе исследованы методические предпосылки, принципы и особенности обучения переводу студентов ВУЗов. Рассмотрены основные этапы и составляющие обучения художественного перевода, а также на основе этих данных разработаны упражнения для обучения устной и письменной художественного перевода будущих переводчиков. Теоретическое значение: систематизация теоретических знаний о художественном стиле английского языка и актуальные направления развития художественного перевода; обобщение методических предпосылок обучения художественному переводу студентов-переводчиков.<br>Goal: studying of the current approaches to the theory and practice of literary translation, their application in the practical activities of translators of literary texts and teaching such techniques to the students in the course of translation studies. Scientific problem: Nowadays there is a rapid development of translation science associated with the processes of globalization, the active development of intercultural relations and dialogue of cultures in various spheres of human activity. Taking this into account, the theory and practice of translation is constantly faced with new problems and challenges and requires updating in accordance with modern realities and requirements. Research methodology: includes descriptive and comparative methods that were used in the course of theoretical understanding of the research subject; the method of quantitative analysis, contextual analysis and elements of component analysis, as well as translation analysis were applied in the course of practical research on the issue of a cultural approach to the translation of literary texts; the modeling method was used during the development of exercises for teaching literary translation to translation students. The main results and conclusions of the research: Artistic texts are characterized by imagery, aesthetics of speech, expression, depiction, the absence of regulation of the use of linguistic means and methods of their combination, the absence of any standardization of language, the subjectivity of displaying events and realities of life, fantasy as the basis for creating images and reflecting the phenomena of reality. Translation of a literary text is a complex and multifaceted type of human activity and creativity. This is not just a translation of works of fiction and literary texts, but also the transformation of the original text by means of another language, and the interaction and mutual influence of two cultures – source and target, which include the original text and the translated text. Nowadays, the issues of using the principles of adequacy and equivalence of literary translation, as well as the phenomenon of “cultural revolution” in the field of literary translation, which involves the use of strategies for domestication and forenization of culturally marked elements of literary text, are becoming topical areas of research into the translation of literary texts. The paper analyzes the translation of an English-language literary work, containing culturally specific information, which showed that quite often the translator cannot cope with the reproduction of such information in translation. The reasons for the wrong choice of translation strategy may be an insufficient level of background knowledge of the translator, the lack of effective translation approaches to the transfer of cultural elements, etc. The methodological principles and features of teaching translation university students. The main stages and components of literary translation training are considered, and on the basis of these data, exercises have been developed for teaching interpretation and literary translation of future translators. Theoretical meaning: systematization of theoretical knowledge on the literary style of the English language and current trends in the development of literary translation; generalization of the methodological prerequisites for teaching literary translation to student translators.

The main aim of this paper is to contribute to the elucidation of electrochemical processes. These processes occur in the investigated experimental lead-acid cell. For this purpose, electrochemical impedance spectroscopy was used. There are two methods of measurement presented. First one is used to measure impedance between electrodes. Second one is used to measure impedance of collector ribs inside positive or negative electrode. The results are represented by electrical equivalent circuits, whose elements are described in detail in the theoretical part.

Non contributory periods is one of the key issues in the public discussion on the planned reform of the pension system in the Czech Republic and is being widely discussed by economists, social scientists and political representatives. The PhD thesis focuses on a detailed analysis of non-contributory periods in the Czech pension system and their impact on pension system balance and micro and macro economic connections. It includes an international comparison of non contributory periods and a minute description of one selected non contributory period -- child care in selected European countries. The extent of non contributory periods considered in the pension system represents one of the theoretical possibilities of parametric changes to the pension insurance system. Non contributory periods are taken into account in pension schemes either because the individual is carrying out a non-wage-earning activity beneficial to society or because the individual through no fault of their own finds themselves in an (adverse) social situation which from a humanitarian perspective justifies their participation in pension insurance without making insurance payments. The institution of non contributory periods helps to secure the universality of the pension system, which enables the participation of economically inactive persons in the pension insurance system. The amount of non contributory periods or the proportion between non contributory periods and years worked, or the proportion between paid insurance and non contributory periods (potential loss of insurance contributions) has, to date, merely been estimated in the Czech Republic. This PhD thesis presents the first accurate figures, based on unique individual data on insured persons; methods of analysis, synthesis, comparison, simulations were used and statistical methods were applied. The analysis reveals that non contributory periods are a significant element of the Czech pension system amounting to 22.4% of the total insurance period which is unacceptable especially as regards the principle of equivalence. The average duration of non-contributory periods for current pensioners is 8.7 years. The proportion of hypothetical insurance calculated from the average wage at potential total income from insurance was in the observed year 30% or 13% (calculation based on the minimum wage). Non contributory periods in the Czech pension system have a significant impact on its balance. Paying premiums for non contributory periods (included in pension law) would cause a decrease in the contribution rate to 18% (calculation based on the average wage). If non contributory periods were not considered, the potential savings on pensions paid out would be almost CZK 35 billion in the observed year. That represents 16.5% of expenditure on pension payments and more than twice the deficit of the pension insurance account for the observed year. Therefore the author recommends in the thesis the restriction of non contributory periods and the introduction of payments for such non-contributory periods from those people who will be entitled to a pension from such non contributory periods in the future.

Esta dissertação tem como objetivo discutir sob quais condições uma G- estrutura é integrável. Primeiro apresentam-se fibrados principais, vetoriais e outras estruturas a elas associados como torção, espaços verticais, espaços horizontais e conexões. Depois apresentam-se a definição de G-estrutura, de integrabilidade de G-estruturas, com exemplos e as respectivas versões de integrabilidade e equivalência de G-estruturas. Finalmente, são descritas condições mais gerais que garantem a integrabilidade de G-estruturas.<br>This dissertation aims to discuss what are the conditions for the inte- grability of a G-structure. We begin presenting principal bundles, vectoer bundles, associated bundles and other structures related to them like torsion, vertical spaces, horizontal spaces and connections. After this, we present the definition of G-structure, integrability os G-structures with examples ans respectives versions of integrabilities and the equivalence of G-estructures. Finally, we describe more general conditions that ensure the integrability of G-structures.

Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.