In this study spectral and photometric data of the SAX J2103.5+4545 Be/X-ray system are given. The spectral data were taken from June 2007 to September 2008 with the 1.5 m Russian-Turkish telescope, whereas the photometric data were obtained using ROTSE-IIId archive from June 2004 to November 2008. The photometric data up to April 2007 shows that the system was in quiescence in the optical region. But, in the 23rd of April 2007, the system&#039 / s luminosity underwent a large increase, which is in agreement with X-ray data. This increase was approximately 1 mag. Also, the Halpha line was displaying an emission with increased equivalent width proportional to the outburst. Afterwards, the Halpha line profile changed from a double peaked emission into a single peaked absorption, which is in agreement with the system&#039 / s structure. This means that the Be star threw away its disc and its light curve fell back to its old luminosity.

L’interférométrie optique/IR à longue base a été récemment mise en place comme une technique capable de résoudre spatialement les étoiles et leurs environnements circumstellaires au niveau de la milliseconde d'angle (mas). Cette haute résolution ouvre toute une nouvelle fenêtre pour l'étude des systèmes astrophysiques, fournissant des informations inaccessibles par d'autres techniques. Les disques astrophysiques sont observés dans une grande variété de systèmes, de galaxies jusqu'aux anneaux planétaires, partageant communément des processus physiques similaires. Deux disques particuliers sont étudiés dans la thèse: (i) les étoiles B He-riches qui présente des champs magnétiques de l'ordre de kG et que confine leurs vents dans des structures appelées magnétosphères; et (ii) les étoiles Be, rotateurs rapides qui présentent des disques circumstellaires épisodiques. Cette étude utilise la technique interférométrique pour étudier à la fois la photosphère et l'environnement circumstellaire de ces étoiles. L'objectif est de combiner l'interférométrie avec d'autres techniques d'observation (telles que la spectroscopie et la polarimétrie) pour effectuer une description physique complète et bien contraindre ces systèmes. Cette description est acquise par l'interprétation de l'ensemble des observations par des modèles de transfert radiatif. / Optical long baseline interferometry was recently established as a technique capable of resolving stars and their circumstellar environments at the milliarcsecond (mas) resolution level. This high-resolution opens an entire new window to the study of astrophysical systems, providing information inaccessible by other techniques. Astrophysical disks are observed in a wide variety of systems, from galaxies up to planetary rings, commonly sharing similar physical processes. Two particular disk like systems are studied in the thesis: (i) B He-rich stars that exhibits magnetic fields in order of kG and that trap their winds in structures called magnetospheres; and (ii) Be stars, fast rotating stars that create circumstellar viscous disks. This study uses the interferometric technique to investigate both the photosphere proper and the circumstellar environment of these stars. The objective is to combine interferometry with other observational techniques (such as spectroscopy and polarimetry) to perform a complete and well-constrained physical description of these systems. This description is accompanied by radiative transfer models.

Estrelas Be são reconhecidas pela sua rápida rotação e pulsação não radial. São as únicas estrelas da Sequência Principal que apresentam discos circunstelares, os quais são formados por meio de processos ainda não completamente compreendidos. A modelagem das forças que atuam neste sistema conduz a previsões teóricas sobre a estrutura do disco que podem ser comparadas com dados observacionais. Podemos estudar as propriedades físicas dos discos de estrelas Be pelo efeito que a luz estelar sofre ao passar por eles, por exemplo, modelando a transferência radiativa. Neste ponto, a polarização surge como uma ferramenta muito útil para a investigação destes discos, permitindo a determinação de quantidades físicas importantes do sistema, como a densidade numérica de partículas e o ângulo de inclinação. Uma variabilidade intrigante observada em estrelas Be é a transição aperiódica entre uma fase B normal (sem disco) e uma fase Be (com disco). Estudos de monitoramento recentes encontraram, a partir da análise da polarização intrínseca decorrente da transição entre estas fases, uma relação significante entre a mudança da polarização através do salto de Balmer versus a polarização na banda V, fazendo surgir uma estrutura em loop como função do tempo, no assim denominado Diagrama Cor-Polarização. Neste trabalho, apresentamos uma análise do Diagrama Cor-Polarização por meio de modelos diversos. Fazemos uso do Disco de Decréscimo Viscoso que é o paradigma atual para explicar a formação e evolução dos discos de estrelas Be. Com isso, visamos determinar como a polarimetria pode contribuir para a compreensão dos mecanismos fundamentais envolvidos no processo de formação e dissipação do disco. / Be stars are recognized by their rapid rotation and non-radial pulsation. They are the only stars in the Main Sequence that have circumstellar disks that are formed by processes not yet fully understood. The modeling of the forces acting on this system leads to theoretical predictions about the structure of the disk that can be compared to observational data. We can study physical the properties of Be disks by modeling how stellar light is reprocessed by them. This requires solving the detailed radiative transfer problem involved. In this point, the study of polarization arise as a useful tool to investigate these disks, allowing for the determination of important physical quantities of the system, such as the particle number density and inclination angle. An intriguing variability observed in Be stars is the aperiodic transition between a B normal phase (without disk) to a Be phase (with disk). Recent monitoring studies found, from the analysis of the intrinsic polarization arising of the transition between these phases, a significant relation between the polarization change through the Balmer jump versus the V-Band polarization, giving rise to a loop structure as a function of time, in the so-called Color-Polarization Diagram. This work presents an analysis of the Color-Polarization Diagram by several models. We make use of the Viscous Decretion Disk Model, which assumes the existence of some injection mechanism of material at keplerian velocities in the disk base, where the turbulent viscosity acts carrying angular momentum from de inner parts to the outer regions. With this, we aimed to extend our knowledge about the fundamental mechanisms involved in the formation and dissipation processes of the disk.

The brightness and proximity of many classical Be stars makes them perfect laboratories for studying the physics of astrophysical disks. They are also among the most popular targets for optical/IR interferometers, which are able to fully resolve their circumstellar disks, to which much of the recent progress in our understanding of these enigmatic objects is owed. The current consensus is that classical Be stars eject material from the stellar surface into Keplerian orbits, thus forming a disk, whose subsequent evolution is governed by turbulent viscosity, which is the basis of the so-called viscous decretion disk (VDD) model. Among the main results of the present work is arguably the best-constrained model of a particular Be star β CMi. The VDD predictions were confronted also with radio observations, which allowed for the first determination of the physical extent of a Be disk. This result subsequently led to the detection of a binary companion, which is truncating the disk by tidal forces. Extending the sample to include five more targets led to revealing a similar outer disk structure in all of them. The range of explanations includes the most plausible scenario, in which the truncation of Be disks by (unseen) companions is much more common than previously thought.

Right to be Forgotten - Right to Privacy in the Internet Age Abstract The first chapter of the diploma thesis aims to identify the threats to human privacy and forgetting that were brought on by the advancements in the field of information and communication technology in the recent decades. Both privacy and forgetting have important functions in the life of the individual, as well as on the societal level. The protection of those functions, whose analysis can be found in the second chapter of the diploma thesis, is one of the basic tasks of modern, liberal and democratic societies. Unless we want to leave the evolution of our civilization up to the technological developments and their often unforeseen (and unforeseeable) consequences, it is imperative that we systematically evaluate their impact on society. Such evaluations should then serve as bases for devising regulation (both legal and non- legal) that would eliminate or at least mitigate the identified societal threats. In the context of human privacy and forgetting, one of the outcomes of such an impact assessment and regulatory consideration is the right to be forgotten. This right can be seen as a legal instrument protecting the informational aspect of human privacy, or rather the informational self-determination of individuals, in the new reality...

Este trabalho tem como objetivo o estudo, caracterização elétrica e modelagem do novo transistor desenvolvido e fabricado no Laboratório de Sistemas Integráveis (LSI) da Universidade de São Paulo (USP) chamado BE (Back Enhanced) SOI MOSFET. Trata-se de um dispositivo inovador que se destaca principalmente pela sua facilidade de fabricação (exigindo apenas processos bem conhecidos e nenhuma etapa de dopagem do semicondutor) e sua flexibilidade quanto ao modo de operação (pode atuar como um transistor MOS tipo n ou um transistor MOS tipo p, dependendo somente da polarização de substrato). Aplicando-se tensão no substrato (VGB) é possível formar um canal de elétrons (VGB>0) ou lacunas (VGB<0) na segunda interface da camada de silício, por onde a corrente entre fonte e dreno flui. Sua patente foi requerida junto ao INPI (Instituto Nacional da Propriedade Industrial) sob o número BR 10 2015 020974 6. Foram realizadas medidas elétricas e simulações numéricas para melhor compreender seu princípio de funcionamento e as características que tornam possível sua reconfigurabilidade. Duas fabricações distintas deste tipo de dispositivo foram analisadas. Além das espessuras distintas, a principal diferença entre elas é o metal utilizado nos eletrodos de fonte e dreno, sendo alumínio na primeira e níquel na segunda versão. O alumínio utilizado na primeira versão resultou em contatos Ôhmicos após o processamento térmico das lâminas, que favoreceram o funcionamento do dispositivo como transistor tipo p, devido à natureza do material utilizado. A análise em função da temperatura (de 25ºC até 125ºC) mostrou uma variação da tensão de limiar (até 1,52mV/ºC) e uma degradação da mobilidade dos portadores de carga (analisado através da transcondutância), resultando no surgimento de um ponto invariante com a temperatura, o chamado ZTC (Zero Temperature Coefficient). Já a segunda versão possui contatos Schottky, na qual foram obtidos níveis de corrente apreciáveis tanto para transistores tipo n (na ordem de nA para as condições de polarização utilizadas), quanto para transistores tipo p (na ordem de ?A). O comportamento da curva de corrente de dreno deste dispositivo apresentou uma estabilização a partir de determinado valor de tensão de porta. A partir deste ponto o BE SOI MOSFET deixa de atuar como um transistor convencional e passa a ter sua corrente de dreno proporcional a tensão de substrato. Medidas em função da temperatura nesta segunda versão permitiram comparar os resultados com os da primeira versão. Percebeu-se a ausência do ponto de ZTC, uma vez que foi observado o aumento da corrente devido à diminuição da resistência dos contatos de fonte e dreno para temperaturas mais elevadas. Por fim, a operação de um circuito inversor utilizando o BE SOI MOSFET foi implementada, mesmo quando alternando os tipos dos transistores, comprovando a flexibilidade de funcionamento dos transistores ao mudar seu tipo em função da polarização de substrato. / The aim of this work is the study, the electrical characterization and the modeling of the new transistor that was developed and fabricated in the Laboratório de Sistemas Integráveis (LSI) at University of Sao Paulo (USP). It was named BE (Back Enhanced) SOI MOSFET. This innovative device has the advantage of a simple fabrication (only well-known processes are required to build it and there is no need of any doping step) and it has a reconfigurable operation (it can act as a n-type MOS transistor or as a ptype MOS transistor depending only on substrate bias). The substrate voltage (VGB) is responsible for the formation of an electron (VGB>0) or a hole (VGB<0) channel at the back interface of the silicon, where the drain current flows. The patent for it was required at the National Industrial Property Institute under the number BR 10 2015 020974 6. Electrical measurements and numerical simulations were performed to better understand its functioning principle and the characteristics that enable its reconfigurability. Two different fabrication splits were analyzed. Beside their thicknesses, the main difference between them is the drain and source metal electrode (aluminum in the first split and nickel in the second one). The one with aluminum electrodes resulted in Ohmic contacts after thermal processing, that favored the formation on the p-type transistor because of the nature of the used element. It was observed a variation of the threshold voltage (up to 1.52mV/ºC) and a mobility degradation (seen through the transconductance behavior) as a function of the temperature (from 25ºC to 125ºC), resulting in a zero-temperature coefficient (ZTC) bias point in this device. In this bias condition point, the drain current is almost constant as a function of the temperature, which is a good characteristic especially for analog circuits. The second split has Schottky drain and source contacts, in which appreciable current levels were obtained for both n-type transistors (order of magnitude of nA in the measured bias conditions) and p-type transistors (order of magnitude of ?A). The drain current of this device showed a particular behavior where the drain current stabilizes from a certain gate voltage. In this condition, the BE SOI MOSFET does not act as a conventional transistor anymore and its current is proportional to the substrate bias. Measurements as a function of the temperature were performed in the device too. It was observed an increase of the drain current, differently from the first split, due to the reduction of the source and drain contacts resistances as a function of the temperature. This resulted in the absence of the ZTC point. Finally, the operation of an inverter circuit using BE SOI MOSFET transistors was implemented, even if the type of the transistors were switched. This result shows the flexibility of operation of the transistor, in other words, it is possible to change its type as a function of the substrate bias.

Comparative analysis of representation by the attorney in Czech and Spanish civil proceedings The subject of the diploma thesis is the comparative analysis of representation by the attorney in Czech and Spanish civil proceedings. The first part is dedicated to concepts of civil procedure and it's categories. The second part contains a definition of the concept of representation in the civil procedure and it's categories in the Czech and the Spanish law. The third part which is crucial for this thesis focus on the role and the position of an attorney in the civil procedure and on the relationship between the attorney and his client. The third part is also dedicated to the attorney and the requirements the attorney has to meet according to the law. In case of the attorney, as a professional in law and as a member of a bar association, and in case of the relationship between attorney and his client - Czech and the Spanish law are very similar to each other. However significant differences exist in roles which attorney holds - precisely the extent of his activity as a representative of the participant. One of differences is an existence of the legal institute of the legal representative in the Spanish procedural law. This legal institute does not exist in the Czech procedural law and its functions...

Este trabalho tem como objetivo o estudo, caracterização elétrica e modelagem do novo transistor desenvolvido e fabricado no Laboratório de Sistemas Integráveis (LSI) da Universidade de São Paulo (USP) chamado BE (Back Enhanced) SOI MOSFET. Trata-se de um dispositivo inovador que se destaca principalmente pela sua facilidade de fabricação (exigindo apenas processos bem conhecidos e nenhuma etapa de dopagem do semicondutor) e sua flexibilidade quanto ao modo de operação (pode atuar como um transistor MOS tipo n ou um transistor MOS tipo p, dependendo somente da polarização de substrato). Aplicando-se tensão no substrato (VGB) é possível formar um canal de elétrons (VGB>0) ou lacunas (VGB<0) na segunda interface da camada de silício, por onde a corrente entre fonte e dreno flui. Sua patente foi requerida junto ao INPI (Instituto Nacional da Propriedade Industrial) sob o número BR 10 2015 020974 6. Foram realizadas medidas elétricas e simulações numéricas para melhor compreender seu princípio de funcionamento e as características que tornam possível sua reconfigurabilidade. Duas fabricações distintas deste tipo de dispositivo foram analisadas. Além das espessuras distintas, a principal diferença entre elas é o metal utilizado nos eletrodos de fonte e dreno, sendo alumínio na primeira e níquel na segunda versão. O alumínio utilizado na primeira versão resultou em contatos Ôhmicos após o processamento térmico das lâminas, que favoreceram o funcionamento do dispositivo como transistor tipo p, devido à natureza do material utilizado. A análise em função da temperatura (de 25ºC até 125ºC) mostrou uma variação da tensão de limiar (até 1,52mV/ºC) e uma degradação da mobilidade dos portadores de carga (analisado através da transcondutância), resultando no surgimento de um ponto invariante com a temperatura, o chamado ZTC (Zero Temperature Coefficient). Já a segunda versão possui contatos Schottky, na qual foram obtidos níveis de corrente apreciáveis tanto para transistores tipo n (na ordem de nA para as condições de polarização utilizadas), quanto para transistores tipo p (na ordem de ?A). O comportamento da curva de corrente de dreno deste dispositivo apresentou uma estabilização a partir de determinado valor de tensão de porta. A partir deste ponto o BE SOI MOSFET deixa de atuar como um transistor convencional e passa a ter sua corrente de dreno proporcional a tensão de substrato. Medidas em função da temperatura nesta segunda versão permitiram comparar os resultados com os da primeira versão. Percebeu-se a ausência do ponto de ZTC, uma vez que foi observado o aumento da corrente devido à diminuição da resistência dos contatos de fonte e dreno para temperaturas mais elevadas. Por fim, a operação de um circuito inversor utilizando o BE SOI MOSFET foi implementada, mesmo quando alternando os tipos dos transistores, comprovando a flexibilidade de funcionamento dos transistores ao mudar seu tipo em função da polarização de substrato. / The aim of this work is the study, the electrical characterization and the modeling of the new transistor that was developed and fabricated in the Laboratório de Sistemas Integráveis (LSI) at University of Sao Paulo (USP). It was named BE (Back Enhanced) SOI MOSFET. This innovative device has the advantage of a simple fabrication (only well-known processes are required to build it and there is no need of any doping step) and it has a reconfigurable operation (it can act as a n-type MOS transistor or as a ptype MOS transistor depending only on substrate bias). The substrate voltage (VGB) is responsible for the formation of an electron (VGB>0) or a hole (VGB<0) channel at the back interface of the silicon, where the drain current flows. The patent for it was required at the National Industrial Property Institute under the number BR 10 2015 020974 6. Electrical measurements and numerical simulations were performed to better understand its functioning principle and the characteristics that enable its reconfigurability. Two different fabrication splits were analyzed. Beside their thicknesses, the main difference between them is the drain and source metal electrode (aluminum in the first split and nickel in the second one). The one with aluminum electrodes resulted in Ohmic contacts after thermal processing, that favored the formation on the p-type transistor because of the nature of the used element. It was observed a variation of the threshold voltage (up to 1.52mV/ºC) and a mobility degradation (seen through the transconductance behavior) as a function of the temperature (from 25ºC to 125ºC), resulting in a zero-temperature coefficient (ZTC) bias point in this device. In this bias condition point, the drain current is almost constant as a function of the temperature, which is a good characteristic especially for analog circuits. The second split has Schottky drain and source contacts, in which appreciable current levels were obtained for both n-type transistors (order of magnitude of nA in the measured bias conditions) and p-type transistors (order of magnitude of ?A). The drain current of this device showed a particular behavior where the drain current stabilizes from a certain gate voltage. In this condition, the BE SOI MOSFET does not act as a conventional transistor anymore and its current is proportional to the substrate bias. Measurements as a function of the temperature were performed in the device too. It was observed an increase of the drain current, differently from the first split, due to the reduction of the source and drain contacts resistances as a function of the temperature. This resulted in the absence of the ZTC point. Finally, the operation of an inverter circuit using BE SOI MOSFET transistors was implemented, even if the type of the transistors were switched. This result shows the flexibility of operation of the transistor, in other words, it is possible to change its type as a function of the substrate bias.

No description available.

Development of a hydrocarbon reservoir requires information about the type of fluid that saturates the pore space, and the permeability distribution that determines how the fluid can be extracted. The presence of fractures in a reservoir can be useful for obtaining this information. The main objectives of this thesis are to investigate how fracturing can be detected remotely using exploration seismology. Fracturing will effect seismic data in a number of ways. Firstly, if the fractures are aligned preferentially in some direction, the medium will exhibit long wavelength anisotropy. In turn, if wave propagation is not aligned with one of the symmetry axes of the effective medium then shear wave splitting will depend upon the properties of the fracture filling fluid. Secondly, elastic waves will experience attenuation and dispersion due to scattering and wave-induced fluid flow between the fractures and matrix porosity. This occurs because the fractures are more compliant than the background medium and therefore there will be a pressure gradient formed during passage of the wave, causing fluid to flow between fractures and background. If the direction of shear-wave propagation is not perpendicular or parallel to the plane of fracturing, the wave polarized in the plane perpendicular to the fractures is a quasi-shear mode, and therefore the shear-wave splitting will be sensitive to the fluid bulk modulus. / The magnitude of this sensitivity depends upon the extent to which fluid pressure can equilibrate between pores and fractures during the period of the deformation. In this thesis I use the anisotropic Gassmann equations and existing formulations for the excess compliance due to fracturing to estimate the splitting of vertically propagating shear-waves as a function of the fluid modulus for a porous medium with a single set of dipping fractures and with two conjugate fracture sets dipping with opposite dips to the vertical. This is achieved using two alternative approaches. In the first approach it is assumed that the deformation taking place is quasi-static. That is, the frequency of the elastic disturbance is low enough to allow enough time for fluid to flow between both the fractures and the pore space throughout the medium. In the second approach I assume that the frequency is low enough to allow fluid flow between a fracture set and the surrounding pore space, but high enough so that there is not enough time during the period of the elastic disturbance for fluid flow between different fracture sets to occur. It is found that the second approach yields a much stronger dependency of shear-wave splitting on the fluid modulus than the first one. This is a consequence of the fact that at higher wave frequencies there is not enough time for fluid pressure to equilibrate and therefore the elastic properties of the fluid have a greater effect on the magnitude of the shear-wave splitting. I conclude that the dependency of the shear-wave splitting on the fluid bulk modulus will be at its minimum for quasi-static deformations, and will increase with increasing wave frequency. / In order to treat the problem of dispersion and attenuation due to wave-induced fluid flow I consider interaction of a normally incident time-harmonic longitudinal plane wave with a circular crack imbedded in a porous medium governed by Biot’s equations of dynamic poroelasticity. The problem is formulated in cylindrical coordinates as a system of dual integral equations for the Hankel transform of the wave field, which is then reduced to a single Fredholm integral equation of the second kind. It is found that the scattering that takes place is predominantly due to wave induced fluid flow between the pores and the crack. The scattering magnitude depends on the size of the crack relative to the slow wave wavelength and has its maximum value when they are of the same order. I conclude that this poroelastic effect should not be neglected, at least at seismic frequencies. Using the solution of the scattering problem for a single crack and multiple-scattering theory I estimate the attenuation and dispersion of elastic waves taking place in a porous medium containing a sparse distribution of such cracks. I obtain from this analysis an effective velocity which at low frequencies reduces to the known static Gassmann result and a characteristic attenuation peak at the frequency such that the crack size and the slow wave wavelength are of the same order. / When comparing with a similar model in which multiple scattering effects are neglected I and that there is agreement at high frequencies and discrepancies at low frequencies. I conclude that the interaction between cracks should not be neglected at low frequencies, even in the limit of weak crack density. Since the models only agree with each other at high frequencies, when the time available for fluid diffusion is small, I conclude that the interaction between cracks that takes place as a result of fluid diffusion is negligible at high frequencies. I also compare my results with a model for spherical inclusions and find that the attenuation for spherical inclusions has exactly the same dependence upon frequency, but a difference in magnitude that depends upon frequency. Since the attenuation curves are very close at low frequencies I conclude that the effective medium properties are not sensitive to the shape of an inclusion at wavelengths that are large compared to the inclusion size. However at frequencies such that the wavelength is comparable to or smaller than the inclusion size the effective properties are sensitive to the greater compliance of the flat cracks, and more attenuation occurs at a given frequency as a result.