The electrodynamic interaction of Ganymede’s mini-magnetosphere with Jupiter’s corotating magnetospheric plasma has been shown to give rise to strong current systems closing through the moon and its ionosphere as well as through its magnetopause and magnetotail current sheet. This interaction is strongly evidenced by the presence of aurorae at Ganymede and of a bright Ganymede footprint on Jupiter’s ionosphere. This footprint is located equatorward of the main auroral emissions, at the magnetic longitude of the field line threading Ganymede. The brightness of Ganymede’s auroral footprint at Jupiter along with its latitudinal position have been shown to depend on the position of Ganymede relative to the center of the Jovian plasma sheet. Additionally, observations using the Hubble Space Telescope showed that Ganymede’s auroral footprint brightness is characterized by variations of three different timescales: 5 hours, 10-40 minutes, and ~100 seconds. The goal of the present study is to examine the relationship between the longest and the shortest timescale periodicities of Ganymede’s auroral footprint brightness and the local processes occurring at Ganymede. This is done by coupling a specifically developed brightness model to a three-dimensional multifluid model which tracks the energies and fluxes of the various sources of charged particles that precipitate into Ganymede’s ionosphere to generate the aurora. It is shown that the predicted auroral brightnesses and morphologies agree well with observations of Ganymede’s aurora from the Hubble Space Telescope. Our results also suggest the presence of short- and long-period variabilities in the auroral emissions at Ganymede due to magnetic reconnections on the magnetopause and in the magnetotail, and support the hypothesis of a correlation between the variability of Ganymede’s auroral footprint on Jupiter’s ionosphere and the variability in the brightness and morphology of the aurora at Ganymede. Finally, the modeled aurora at Ganymede reveals that the periodicities in the morphology and brightness of the auroral emissions are produced by two different dynamic reconnection mechanisms. The Jovian flow facing side aurora is generated by electrons sourced in the Jovian plasma and penetrating into Ganymede’s ionosphere through the cusps above the separatrix region. In this case, the reconnection processes responsible for the auroral emissions occur on Ganymede’s magnetopause between the Jovian magnetic field lines and the open magnetic field lines threading Ganymede’s Polar Regions. As for the magnetotail side aurora, it is generated by electrons originating from Ganymede’s magnetospheric flow. These electrons are accelerated along closed magnetic field lines created by magnetic reconnection in Ganymede’s magnetotail, and precipitate into Ganymede’s ionosphere at much lower latitudes, below the separatrix region.

In this thesis, the current vs. magnetic field relationships for four magnets, M1, M2, M3, and Hyperon of FNAL Experiment E781 (the charm baryon study) havel,een studied on the basis of algorithms involving sign corrections pertaining to remedying incorrect FNAL EPICURE readout system's current and magnetic field values for E78 I's 4 magnets.After analyzing previous BSU personnel's work involving re-averaging of the current and magnetic field output values for E78 1, further research was carried out in this thesis activity regarding the correction of the algebraic signs of certain current and magnetic field values in the FNAL EPICURE read out values inputted into E781' data bank.Firstly, a code was developed to merge the four files of current and magnetic fields for the four magnets of E78 1, all into one file. Then, an algorithm for a sign correction program was developed in order to both sort the merged data and correct the current and magnetic field signautomatically.In order to obtain a better understanding of the effect of the incorrect sign for a magnet's current and magnetic field on analysis results, a statistical result was summarized. Finally, some conclusions were obtained. / Department of Physics and Astronomy

Thesis (Ph.D.) - University of St Andrews, January 2008.

A presente tese parte da premissa de que o contexto de transformações radicais nas Tecnologias da Informação e Comunicação (TICs) desdobra-se em mudanças de toda ordem societal, proporcionando, especialmente, novos modos de subjetivação e cognição a partir da condição habitativa da rede. Tendo isso em vista, examina-se a dissociação entre a cultura tecnocientífica e a cultura das humanidades, ainda presente no modo de produção educacional contemporâneo, a partir das formulações elaboradas por C.P. Snow e Edgar Morin. Discutem-se também alguns parâmetros dos diagnósticos e analisam-se as divergências e pontos comuns nas proposições de ambos os autores. Em um segundo momento, a problemática das “duas culturas” é o pano de fundo de uma reflexão sobre a possibilidade de uma Filosofia da Tecnociência constituir-se em uma estratégia pedagógica relevante para o exercício escolar de religação de saberes, considerando a transversalidade, as hibridações, as tramas multidimensionais e os movimentos transfronteiriços que emergem com os fenômenos tecnocientíficos contemporâneos. Sendo assim, estrategicamente propõe-se a emergência de práticas pedagógicas de matriz filosófica no horizonte transdisciplinar das questões tecnocientíficas. Por fim, entende-se que o atual contexto das tecnologias da conectividade engendra um novo paradigma de inteligibilidade a partir das redes, colaborando para a emergência de um ethos de religação que repercute significativamente no problema das “duas culturas” e na cartografia do saber. / This thesis assumes that the context of radical changes in Information and Communication Technology (ICT) unfolds changes of all societal order, especially providing new forms of subjectivation and cognition from the inhabiting condition in the network. With this in mind, it examines the dissociation between technoscientific culture and the culture of the humanities still present in the contemporary educational production mode, from the formulations developed by C.P. Snow and Edgar Morin. Some parameters of diagnoses are also discussed and the differences and similarities in the propositions of both authors are analyzed. In a second moment, the issue of " the two cultures" is the background for a reflection on the possibility of constituting a Philosophy of Technoscience as a relevant pedagogical strategy for the school exercise of reconnecting knowledge, taking into account the transversality, the hybridizations, the multidimensional plots and transborder movements that emerge with contemporary technoscientific phenomena. Therefore, the emergence of pedagogical practices of philosophical roots in the transdisciplinary horizon of technoscientific issues is strategically proposed. Finally, it is understood that the current context of connectivity technologies engenders a new paradigm of intelligibility from the networks, contributing to the emergence of an ethos of reconnection that significantly affects the issue of two cultures and the cartography of knowledge.

A presente tese parte da premissa de que o contexto de transformações radicais nas Tecnologias da Informação e Comunicação (TICs) desdobra-se em mudanças de toda ordem societal, proporcionando, especialmente, novos modos de subjetivação e cognição a partir da condição habitativa da rede. Tendo isso em vista, examina-se a dissociação entre a cultura tecnocientífica e a cultura das humanidades, ainda presente no modo de produção educacional contemporâneo, a partir das formulações elaboradas por C.P. Snow e Edgar Morin. Discutem-se também alguns parâmetros dos diagnósticos e analisam-se as divergências e pontos comuns nas proposições de ambos os autores. Em um segundo momento, a problemática das “duas culturas” é o pano de fundo de uma reflexão sobre a possibilidade de uma Filosofia da Tecnociência constituir-se em uma estratégia pedagógica relevante para o exercício escolar de religação de saberes, considerando a transversalidade, as hibridações, as tramas multidimensionais e os movimentos transfronteiriços que emergem com os fenômenos tecnocientíficos contemporâneos. Sendo assim, estrategicamente propõe-se a emergência de práticas pedagógicas de matriz filosófica no horizonte transdisciplinar das questões tecnocientíficas. Por fim, entende-se que o atual contexto das tecnologias da conectividade engendra um novo paradigma de inteligibilidade a partir das redes, colaborando para a emergência de um ethos de religação que repercute significativamente no problema das “duas culturas” e na cartografia do saber. / This thesis assumes that the context of radical changes in Information and Communication Technology (ICT) unfolds changes of all societal order, especially providing new forms of subjectivation and cognition from the inhabiting condition in the network. With this in mind, it examines the dissociation between technoscientific culture and the culture of the humanities still present in the contemporary educational production mode, from the formulations developed by C.P. Snow and Edgar Morin. Some parameters of diagnoses are also discussed and the differences and similarities in the propositions of both authors are analyzed. In a second moment, the issue of " the two cultures" is the background for a reflection on the possibility of constituting a Philosophy of Technoscience as a relevant pedagogical strategy for the school exercise of reconnecting knowledge, taking into account the transversality, the hybridizations, the multidimensional plots and transborder movements that emerge with contemporary technoscientific phenomena. Therefore, the emergence of pedagogical practices of philosophical roots in the transdisciplinary horizon of technoscientific issues is strategically proposed. Finally, it is understood that the current context of connectivity technologies engenders a new paradigm of intelligibility from the networks, contributing to the emergence of an ethos of reconnection that significantly affects the issue of two cultures and the cartography of knowledge.

A presente tese parte da premissa de que o contexto de transformações radicais nas Tecnologias da Informação e Comunicação (TICs) desdobra-se em mudanças de toda ordem societal, proporcionando, especialmente, novos modos de subjetivação e cognição a partir da condição habitativa da rede. Tendo isso em vista, examina-se a dissociação entre a cultura tecnocientífica e a cultura das humanidades, ainda presente no modo de produção educacional contemporâneo, a partir das formulações elaboradas por C.P. Snow e Edgar Morin. Discutem-se também alguns parâmetros dos diagnósticos e analisam-se as divergências e pontos comuns nas proposições de ambos os autores. Em um segundo momento, a problemática das “duas culturas” é o pano de fundo de uma reflexão sobre a possibilidade de uma Filosofia da Tecnociência constituir-se em uma estratégia pedagógica relevante para o exercício escolar de religação de saberes, considerando a transversalidade, as hibridações, as tramas multidimensionais e os movimentos transfronteiriços que emergem com os fenômenos tecnocientíficos contemporâneos. Sendo assim, estrategicamente propõe-se a emergência de práticas pedagógicas de matriz filosófica no horizonte transdisciplinar das questões tecnocientíficas. Por fim, entende-se que o atual contexto das tecnologias da conectividade engendra um novo paradigma de inteligibilidade a partir das redes, colaborando para a emergência de um ethos de religação que repercute significativamente no problema das “duas culturas” e na cartografia do saber. / This thesis assumes that the context of radical changes in Information and Communication Technology (ICT) unfolds changes of all societal order, especially providing new forms of subjectivation and cognition from the inhabiting condition in the network. With this in mind, it examines the dissociation between technoscientific culture and the culture of the humanities still present in the contemporary educational production mode, from the formulations developed by C.P. Snow and Edgar Morin. Some parameters of diagnoses are also discussed and the differences and similarities in the propositions of both authors are analyzed. In a second moment, the issue of " the two cultures" is the background for a reflection on the possibility of constituting a Philosophy of Technoscience as a relevant pedagogical strategy for the school exercise of reconnecting knowledge, taking into account the transversality, the hybridizations, the multidimensional plots and transborder movements that emerge with contemporary technoscientific phenomena. Therefore, the emergence of pedagogical practices of philosophical roots in the transdisciplinary horizon of technoscientific issues is strategically proposed. Finally, it is understood that the current context of connectivity technologies engenders a new paradigm of intelligibility from the networks, contributing to the emergence of an ethos of reconnection that significantly affects the issue of two cultures and the cartography of knowledge.

Non-ideal magnetohydrodynamic (MHD) effects may play a significant role in determining the dynamics, thermal properties, and observational signatures of radiatively inefficient accretion flows onto black holes. In particular, particle acceleration during magnetic reconnection events may influence black hole spectra and flaring properties. We use representative general relativistic magnetohydrodynamic (GRMHD) simulations of black hole accretion flows to identify and explore the structures and properties of current sheets as potential sites of magnetic reconnection. In the case of standard and normal evolution (SANE) disks, we find that in the reconnection sites, the plasma beta ranges from 0.1 to 1000, the magnetization ranges from 10(-4) to 1, and the guide fields are weak compared with the reconnecting fields. In magnetically arrested (MAD) disks, we find typical values for plasma beta from 10(-2) to 10(3), magnetizations from 10(-3) to 10, and typically stronger guide fields, with strengths comparable to or greater than the reconnecting fields. These are critical parameters that govern the electron energy distribution resulting from magnetic reconnection and can be used in the context of plasma simulations to provide microphysics inputs to global simulations. We also find that ample magnetic energy is available in the reconnection regions to power the fluence of bright X-ray flares observed from the black hole in the center of the Milky Way.

No description available.

Magnetic reconnection is a fundamental process that changes magnetic field configuration and converts a magnetic energy to flow energy and plasma heating. It can be found in a plasma with frozen magnetic field lines at boundaries where different magnetic field topologies encounter each other and thin current sheets are created as it is typical in the solar wind. In the thesis, we have used spacecraft measurements of solar wind plasma and magnetic field to found magnetic reconnection exhausts. We analyze and compare them with theoretical predictions. The results of the statistical analysis oriented on re-distribution of the magnetic energy in reconnection showed that both a portion of the energy deposited into heat as well as the energy spent on an acceleration of the exhaust plasma increase with the magnetic shear angle in accord with the increase of the magnetic flux available for reconnection. Moreover, we identify unusual events in the solar wind; we found magnetic reconnection exhausts accompanied by one or two side jets and explained their possible causes.

The High Seas, the areas of the ocean beyond national jurisdiction, are experiencing a starkincrease in industrial activities, ranging from fishing to deep sea mining to offshore oil and gasextraction. Marine resources are exploited unsustainably and the benefits of this exploitationare shared unequally. This suggests the need for a transformation, a shift in the deeper structuresof the system, such as underlying paradigms and mind-sets. Engaging with alternative futuresby employing imaginative scenarios can help to question current unsustainable trajectories,uncover alternate possibilities as well as offer aspirational visions of the future. In this thesis, Iargue that depictions of the future that are mere extrapolations of the present do not account fornon-linear changes and surprise, do not explore how current trajectories can be changed andconstrain the capacity to imagine possible futures. Instead, I use a method to address this gapby combining computational text analysis with a structured yet creative scenario buildingapproach. This process results in four science fiction scenario stories, which account for thecomplexity of the system, embrace future uncertainty and engage the imagination, thusdescribing truly novel, transformed futures. The scenario stories are then related back to currentrealities, using the concept of imaginaries, demonstrating that radically futuristic stories can betraced back to the scientific evidence they were based upon. In reference to these results, I arguethat engaging with creative scenario stories can open up transformative spaces to reimagine therelationships between humans and the oceans they depend upon. Further, the scenario storiespresented in this thesis emphasize the vastness of future option space, the plurality of possiblefutures and the subsequent need to continuously explore these uncertain futures from a diversityof perspectives, employing a diversity of methods.