No description available.

The petrology of the Sutherland Commonage olivine melilitite intrusives have been investigated using petrographic and chemical methods. The occurrence consists of a ring dyke which surrounds a centrally located sill complex. The rock of the ring dyke is a typical melilitite which consists of olivine in a groundmass of melilite, clinopyroxene, opaque spinel, nepheline and perovskite. The sill complex is a multiple intrusion and is comprised of a lower green melilitite and an overlying (and younger) grey melilitite. The green melilitite is deuterically altered and the original mineralogy is destroyed to a large extent. The grey melilitite contains autoliths of the green and is a fairly typical monticellitic melilitite in which phenocrysts of olivine are set in a groundmass of melilite, monticellite, opaque spine!, nepheline and perovskite. Microprobe analyses of clinopyroxenes indicate that they are aluminous titanian diopsides and salites which exhibit complex zonation patterns. They record magmatic conditions ranging from the intrusive stage to a final phase of magmatic evolution during which a vapour phase evolved after the majority of the groundmass minerals had crystallised. The chemistry of olivine phenocrysts suggests that the parent magma to the Commonage intrusives accumulated in a temperature-zoned reservoir at the base of the lithosphere. Large, unzoned olivine phenocrysts crystallised in this chamber. Subsequent rupture of the chamber and ascent of magma led to supercooling and the crystallisation of abundant, strongly zoned phenocrysts of smaller size. Olivine crystallisation continued until the magma reached crustal levels. It is inferred from the chemistry of chromites and magnetites that the magma in the ring dyke was more evolved than those in the sill complex and that very oxidising conditions prevailed in the grey melilitite during the crystallisation of magnetite in this intrusive type. The high fO₂ may have resulted from the degassing of CO₂ after intrusion. Major and trace elements have been analysed for in eleven whole rock samples and the ⁸⁷Sr/⁸⁶Sr ratio was determined for seven of the same samples. The results of the geochemical study suggest that the Commonage melilitites were derived by the melting of a recently metasomatised region of the asthenosphere, probably under the influence of an ocean-island-type hotspot situated in the lower mantle.

No description available.

Tübingen, Universiẗat, Diss., 2002.

Tesis para optar al grado de Doctor en Literatura Hispanoamericana y Chilena

No description available.

Thesis (Pd. D.)--Toronto.

Orientador: Gastão Inácio Krein / Banca: Caio H. Lewenkpof / Banca: Gerson Francisco / Resumo: Nesta dissertação tratamos do problema de caos dinâmico na interação de baixas energias de dois monopólos magnéticos não-Abelianos do tipo Bogomol'nyi-PrasadSommerfield (BPS). Monopólos magnéticos BPS são soluções solitônicas das equações clássicas de movimento da teoria de gauge não-Abeliana de Yang-Mills-Higgs SU(2), em que o potencial de Higgs é colocado igual a zero. O movimento clássico de monopólos magnéticos, no limite de velocidades relativas baixas, pode ser descrito por um movimento geodésico no espaço de soluções estáticas de mínima energia em termos de coordenadas coletivas. O conhecimento da métrica para este espaço de coordenadas coletivas é suficiente para determinar a dinâmica de baixas energias de um conjunto de monopólos. Paxa o caso de dois monopólos, a métrica de AtiyahHitchin é a de interesse. O problema pode ser colocado na forma de um sistema dinâmico hamiltoniano não-integrável, em que as soluções das equações de movimento derivadas a partir desta métrica indicam a presença de caos. Superfícies de seção de Poincaré, espectros de potência e expoentes de Lyapunov das soluções dependentes do tempo são calculados numericamente paxa caracterizar soluções caóticas deste sistema dinâmico / Abstract: Abstract In this dissertation we treat the problem of dynamical chaos in the low energy interaction of two non-Abelian magnetic monopoles of the Bogomol'nyi-Prasad-Sommerfield (BPS) type. BPS magnetic monopoles are solitonic Solutions of the classical equations of motion of the non-Abelian Yang-Mills-Higgs SU(2) gauge theory in which the Higgs potential is taken to be equal to zero. The classical motion of the magnetic monopoles in the limit of low relative speed can be described by a geodesic motion in the space of minimum energy static Solutions in terms of collective coordinates. Knowledge of the metric of this space of collective coordinates is suffcient to determine the low energy dynamics of a set of monopoles. For the case of two monopoles, it is the metric of Atiyah-Hitchin which is of interest. The problem can be formulated as a non-integrable dynamical hamiltonian system, in which the Solutions of the equations of motion derived from this metric indicate the presence of chaos. Poincaré surfaces of section, power spectra and Lyapunov exponents of the time-dependent solutions are calculated numerically to characterize chaotic solutions of this dynamical system / Mestre

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-20T15:01:53Z No. of bitstreams: 1 pablomirandaguimaraes.pdf: 1129502 bytes, checksum: 5e2a7668b19414744e2462f3c37afc5b (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-02T11:23:35Z (GMT) No. of bitstreams: 1 pablomirandaguimaraes.pdf: 1129502 bytes, checksum: 5e2a7668b19414744e2462f3c37afc5b (MD5) / Made available in DSpace on 2016-07-02T11:23:35Z (GMT). No. of bitstreams: 1 pablomirandaguimaraes.pdf: 1129502 bytes, checksum: 5e2a7668b19414744e2462f3c37afc5b (MD5) Previous issue date: 2012-04-19 / A análise do crescimento econômico regional e a sua dinâmica temporal-espacial exercem um papel fundamental na tomada de decisão de políticas públicas. O primeiro ensaio aborda a questão da sensibilidade dos valores do coeficiente β de convergência a diferentes escalas das unidades subnacionais no contexto do Problema da Unidade de Área Modificável (MAUP). Houve a constatação do problema de escala espacial tanto em termos de magnitude dos valores de β quanto em termos de níveis de significância estatística. O segundo ensaio adota a análise multinível espacial com o objetivo de constatar a influência das variáveis de infraestruturas econômicas na convergência de renda, bem como de averiguar se a questão do problema de escala espacial poderia ser solucionada. Os resultados obtidos mostraram que a infraestrutura rodoviária exerce influência na determinação da convergência de renda municipal. Todavia, a análise multinível espacial não foi capaz de solucionar a sensibilidade dos coeficientes β de convergência a modificações nas escalas espaciais. / The analysis of regional economic growth and its spatio-temporal dynamics exert a key role on the decision-making of public policies. The first essay is aimed at analyzing the issue about the sensitivity of the values of beta to different scales of subnational units. The results reveal that there is a scale problem in the income convergence analysis both in terms of the coefficient values and in terms of statistical significance. The second essay aims to adopt the spatial multilevel analysis to address the influence of economic infrastructure stocks on the income convergence, as well as to check if the scale problem is solved. The results showed that the road infrastructure has actually impact on the income convergence at the city level. Nevertheless the spatial multilevel analysis was not able to solve the sensitivity of the beta values to different spatial scales.

No description available.