A Província Alcalina Rio Verde - Iporá, na borda norte da Bacia do Paraná é caracterizada pela presença de intrusões alcalinas com forte assinatura aeromagnética e gravimétrica, apresentando-se como anomalias quase circulares. O trabalho refinou o levantamento gravimétrico na região sudoeste de Goiás, incluindo um levantamento de detalhe sobre as intrusões de Morro do Engenho (ME) e uma intrusão a poucos quilômetros a NE de Morro de Engenho (A2), com informações gravimétricas e aeromagnéticas, e sobre a anomalia gravimétrica próxima à cidade de Britânia, sem informação de anomalia aeromagnética. As anomalias gravimétricas variam de 15 a 30 mGal com relação ao campo gravimétrico regional, enquanto que as anomalias aeromagnéticas são da ordem de ±3000nT. Foram feitas também medidas das propriedades petrofísicas de amostras da área. Os resultados da inversão 2D e 3D dos dados gravimétricos e 3D dos dados magnéticos indicam que os corpos alongam-se dentro da crosta superior até a profundidade máxima de 10 km e diâmetro da ordem de 8 km, com geometria aproximadamente cilíndrica. Os dados gravimétricos e aeromagnéticos de ME foram tratados de forma conjunta por modelamento direto (2,5D) onde foi incluída a magnetização remanescente, os resultados obtidos indicam que o volume do corpo anômalo é da ordem de 980 km3. / The Alkaline Province Rio Verde - Iporá, in the north border of the Paraná Basin is characterized by the presence of alkaline intrusions with strong gravity and magnetic signature. This project implemented a gravity survey in the Southwest of Goiás, including a detail one on Morro do Engenho Complex (ME), and one a few kilometers towards NE from ME over an aeromagnetic anomaly known as A2, and over a gravity anomaly close to Britânia city. ME and A2 have magnetic anomaly. The gravity anomalies vary from 15 to 30 mGal in relation to the regional gravity field, while the magnetic anomalies are of the order ±3000nT. Measurements of petrophysical properties of samples from the area were also done. The results present the inversion of the gravity and magnetic data, suggesting that the bodies are inside of the superior crust until the maximum depth of 10 km, in a cylindrical form with 8 to 10 km in diameter. 2.5D direct modeling was also done for ME including remanent magnetization and was performed at the two data sets together, the obtained results indicate that the close volume of the anomalous body it is 980 km3.

This thesis is based on four essays dealing with tourism development and its determinants. Chapter Two explores the different definitions of ‘tourism’ and ‘tourist’, as well as the factors that influence tourism arrivals. We discuss traditional and more recent theories that underlie the study of the tourism industry. The third chapter examines the effect of tourism upon economic growth, investigating the effects of tourism specialization within tourism-exporting countries and non-tourism-exporting countries annually over the period 1995–2007, applying panel-data methods in cross-sectional growth regressions. This study finds that tourism does not affect economic growth in either underdeveloped or developed countries. Moreover, tourism might cause Dutch Disease in tourism-exporting countries owing to their over-reliance on the exporting of non-traded goods. Chapter Four seeks to identify how institutional quality and aspects of infrastructure (internet access measured by size of country or per 100 people) influence tourist arrivals in a whole sample of 131 countries and in sub-samples comprising developed and developing countries (as defined by IMF criteria) using static and dynamic panel data. The findings indicate that internet access enhances the tourism industry, and most interestingly, that good governance is one of the most influential factors for improving and developing tourism. Chapter Five diagnoses the determinants of tourism flows using panel-data sets including 134 originating countries and 31 destination countries (selected depending on data availability) focusing on ICRG data for the period 2005–2009. The methodology makes use of basic and augmented gravity equations, together with the Hausman-Taylor and Poisson estimation techniques, whilst comparing the performance of the three gravity-equation methods. The results suggest that lower levels of political risk contribute to an increase in tourism flows. Furthermore, common language (positively), common currency (negatively) and political factors (particularly institutional quality) are the most prominent determinants in promoting (or deterring) tourism. Chapter Six gives concluding remarks.

Regional-scale complete Bouguer gravity anomalies underlying the Lassen and Shasta -Medicine Lake regions in northern California and southern Oregon are associated with subduction of the Gorda plate beneath North America. These generally negative anomalies reflect where underplating has deepened to form the mantle wedge, and where subduction has given rise to a series of Quaternary volcanoes comprising the southernmost end of the Cascade range. Multiple conductive bodies were identified by Park and Ostos (2013) in their magnetotelluric (MT) study of the broader Lassen volcanic region. Their broadband and long period measurements were conducted along a 250 km profile spanning from the California-Nevada border, to just west of the Great Valley in California. Utilizing their MT conductor geometries as a starting point, a forward gravity model was generated along the same profile, and agrees well with what they interpret to be the locations and depths of mid-crustal magma bodies in the Lassen and surrounding regions. The excess mass and volume of modeled anomaly (a) - most closely attributed to underlying Lassen Peak - were estimated at -2 x 1014 kg and 7 x 1011 m3, respectively.

Isostatic equilibrium is commonly defined as the state achieved when there are no lateral gradients in hydrostatic pressure, and thus no lateral flow, at depth within the lower viscosity mantle that underlies a planetary body's outer crust. In a constant-gravity Cartesian framework, this definition is equivalent to the requirement that columns of equal width contain equal masses. Here we show, however, that this equivalence breaks down when the spherical geometry of the problem is taken into account. Imposing the "equal masses" requirement in a spherical geometry, as is commonly done in the literature, leads to significant lateral pressure gradients along internal equipotential surfaces and thus corresponds to a state of disequilibrium. Compared with the "equal pressures" model we present here, the equal masses model always overestimates the compensation depth-by similar to 27% in the case of the lunar highlands and by nearly a factor of 2 in the case of Enceladus. Plain Language Summary "Isostasy" is the principle that, just as an iceberg floats on the water, crustal rocks effectively float on the underlying higher density mantle, which behaves essentially like a fluid on geologic timescales. Although there are subtle inconsistencies among the various ways isostasy can be defined, they have not been historically problematic for bodies like the Earth, where the crust is thin compared with the overall radius. When the thickness of the crust is a nonnegligible fraction of a planetary body's radius, however, it becomes important to take the spherical geometry into account. In this case, the inconsistencies in the definitions can lead to significant discrepancies. Here we argue that one of the most commonly used approaches, which requires equal width columns to contain equal masses, always results in overestimating the crustal thickness. In particular, we suggest that the lunar and Martian highlands crustal thickness may have been overestimated by similar to 27% and similar to 10%, respectively, and that the ice shell thickness for Saturn's small icy moon Enceladus may have been overestimated by nearly a factor of 2.

The thesis tries to investigate which impact the new Silk Road announced 2013 by the Chinese president has on EU-China trade potentials. The so called OBOR initiative is an infrastructure project that aims to promote trade facilitation along the ancient Silk Road. The initiative includes more than 60 countries. The gravity model of trade will be applied to run a simulation exercise to estimate trade potentials from the EU to China and vice versa. The results suggest that China can increase its trade potential to the EU. Among the EU countries there are winners and losers. Those countries which participate in the initiative will benefit from an increased trade potential others will lose trade potential.

Orbit determination has long relied on the use of the Kalman filter, or specifically the extended Kalman filter, as a means of accurately navigating spacecraft. With the advent of cheaper, more powerful computers more accurate techniques such as the particle filter have been utilized. These Bayesian types of filters have in more recent years found their way to other applications. Dr. Furfaro and B. Gaudet have demonstrated the ability of the particle filter to accurately estimate the angular velocity, homogenous density, and rotation angle of a non-uniformly rotating ellipsoid shaped asteroid. This paper extends that work by utilizing a particle filter to accurately estimate the angular velocity and homogenous density of an ellipsoidal asteroid while simultaneously determining the location and mass of a mass concentration modeled as a point mass embedded within the asteroid. This work shows that by taking measurements in several locations around the asteroid, the asteroid's rotation state and mass distribution can be discerned.

South-East Asian region is the most dynamic region in the world. It is also known for having enormous number of RTAs, which became the main drive force for trade integration. Moreover, China is the leader in this region, changing fast and becoming either a pioneer or a threat for the neighbor countries. This paper uses a gravity model to estimate the influence of RTAs on the countries in the region and attempts to find out whether new agreements will deeper the trade cooperation or make the 'spaghetti bowl' effect even worse.

We investigate several problems in relativity and particle physics where symmetries play a central role; in all cases geometric properties of Lie groups and their quotients are related to physical effects. The first part is concerned with symmetries in gravity. We apply the theory of Lie group deformations to isometry groups of exact solutions in general relativity, relating the algebraic properties of these groups to physical properties of the spacetimes. We then make group deformation local, generalising deformed special relativity (DSR) by describing gravity as a gauge theory of the de Sitter group. We find that in our construction Minkowski space has a connection with torsion; physical effects of torsion seem to rule out the proposed framework as a viable theory. A third chapter discusses a formulation of gravity as a topological BF theory with added linear constraints that reduce the symmetries of the topological theory to those of general relativity. We discretise our constructions and compare to a similar construction by Plebanski which uses quadratic constraints. In the second part we study CP violation in the electroweak sector of the standard model and certain extensions of it. We quantify fine-tuning in the observed magnitude of CP violation by determining a natural measure on the space of CKM matrices, a double quotient of SU(3), introducing different possible choices and comparing their predictions for CP violation. While one generically faces a fine-tuning problem, in the standard model the problem is removed by a measure that incorporates the observed quark masses, which suggests a close relation between a mass hierarchy and suppression of CP violation. Going beyond the standard model by adding a left-right symmetry spoils the result, leaving us to conclude that such additional symmetries appear less natural.

Einstein's theory of general relativity has been the accepted theory of gravity for nearly a century but how well have we really tested it? The laws of gravity have been probed in our solar system to extremely high precision using several different tests and general relativity has passed each one with flying colours. Despite this, there are still some mysteries it cannot account for, one of which being the recently discovered acceleration of the universe and this has prompted a theoretical study of modified theories of gravity that can self-accelerate on large scales. Indeed, the next decade will be an exciting era where several satellites will probe the structure of gravity on cosmological scales and put these theoretical predictions to the test. Despite this, one must still worry about the behaviour of gravity on smaller scales and the vast majority of these theories are rendered cosmologically uninteresting when confronted with solar system tests of gravity. This has motivated the study of theories that differ from general relativity on large scales but include screening mechanisms which act to hide any modifications in our own solar system. This then presents the problem of being able to distinguish these theories from general relativity. In the last few years, astrophysical scales have emerged as a new and novel way of probing these theories. These scales encompass the mildly non-linear regime between galactic and cosmological scales where the astrophysical objects have not yet joined the Hubble flow. For this reason, the screening mechanism is active but not overly efficient and novel effects may be present. Furthermore, these tests do not require a large sample of galaxies and hence do not require dedicated surveys; instead they can piggyback on other experiments. This thesis explores a class of theories of screened modified gravity which are scalar-tensor theories where the field is conformally coupled to matter via the metric and includes chameleon and symmetron models as well as those that screen using the environment-dependent Damour-Polyakov effect. The thesis is split into two parts. The first is aimed at searching for new and novel astrophysical probes and using them to place new constraints on the model parameters. In particular, we derive the equations governing hydrodynamics in the presence of an external gravitational field that includes the modifications of general relativity. Using this, we derive the equations governing the equilibrium structure of stars and show that unscreened stars are brighter and hotter than their screened counterparts owing to the larger nuclear burning rate in the core needed to combat the additional inward force. These theories have the property that the laws of gravity are different in unscreened galaxies from our own. This means that the inferred distance to an unscreened galaxy using a stellar effect that depends on the law gravity will not agree with a measurement using a different method that is insensitive gravitational physics. We exploit this property by comparing the distances inferred using pulsating Cepheid variable stars, tip of the red giant branch stars and water masers to place new constraints on the model parameters that are three orders of magnitude stronger than those previously reported. Finally, we perturb the equations of modified gravity hydrodynamics to first order and derive the equations governing the oscillations of stars about their equilibrium structure. By solving these equations we show that unscreened stars are more stable to small perturbations than screened stars. Furthermore, we find that the oscillation period is far shorter than was previously estimated and this means that the current constraints can potentially be improved using previous data-sets. We discuss these new results in light of current and future astrophysical tests of modified gravity. The final part of this thesis is dedicated to the search for supersymmetric completions of modified theories of gravity. There have been recent investigations into the quantum stability of these models and there is evidence that they may suffer from quantum instabilities. Supersymmetric theories enjoy powerful non-renormalisation theories that may help to avoid these issues. For this reason, we construct a framework for embedding these models into global supersymmetry and investigate the new features this introduces. We show how supersymmetry is broken at a scale set by the ambient density and that, with the exception of no-scale models, supergravity corrections already constrain the model parameters to levels where it is not possible to probe the theories with astrophysics or laboratory experiments. Next, we construct a class of supersymmetric chameleon models and investigate their cosmology. In particular, we find that they are indistinguishable from the LCDM model at the background level but that they may show deviations in the cold dark matter power spectrum that can be probed using upcoming experiments. Finally, we introduce a novel mechanism where a cosmological constant in the form of a Fayet-Illiopoulos term can appear at late times and investigate the constraints this imposes on the model parameter space.

Materials can flow down a slope in a wide range of geophysical and industrial contexts, including lava flows on volcanoes and thin films on coated surfaces. The aim of my research is to provide quantitative insight into these forms of motion and their dependence on effects of the topography, the volume and the rheology of the flowing structure. Numerous different problems are investigated through mathematical models, which are developed analytically and confirmed by laboratory experiments. The initial advance of long lava flows is studied by considering the flow of viscous fluid released on sloping channels. A scaling analysis, in agreement with analog experiments and field data, offers a practical tool for predicting the advance of lava flows and conducting hazard analysis. A simple and powerful theory predicts the structure of flows resulting from any time-dependent release of fluid down a slope. Results obtained by the method of characteristics reveal how the speed of the advancing front depends importantly on the rate of fluid supplied at an earlier time. Viscous flows on surfaces with different shapes are described by similarity solutions to address problems motivated by engineering as well as geophysical applications. Pouring viscous fluid out of a container can be a frustratingly slow process depending on the shape and the degree of tipping of the container. The discharge rate of the fluid is analysed in simple cases, shedding light on how containers can be emptied most quickly in cosmetic and food industries. In a separate study motivated by coating industries, thin films are shown to evolve with uniform thickness as they drain near the top of a horizontal cylinder or sphere. The leading edge eventually splits into rivulets as predicted theoretically and confirmed by experiments. Debris flows can develop levees and trigger avalanches which are studied by considering dense granular flows down a rough inclined plane. Granular materials released down a slope can produce a flowing structure confined by levees or trigger avalanches at regular intervals, depending on the steady rate of supply. The experimental results are discussed using theoretical ideas of shallow granular flows. Finally, materials flowing in long and slender ducts are investigated theoretically to better understand the digestive and urinary systems in biology. The materials are pumped in an elastic tube by translating waves of muscular contraction and relaxation. The deformation of the tube is predicted by solving a free-boundary problem, a similar mathematical exercise to predicting the moving boundaries of materials spreading on slopes.