Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2005. / Includes bibliographical references (p. 131-149).

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 170-195). Also available in electronic version.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references. Also available in electronic version.

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[pt] Métodos estabilizados de elementos finitos são propostos e analisados para problemas de fluidos, com particular ênfase nas equações de Navier-Stokes incomprenssível. Após a apresentação da mecânica dos escoamentos dos fluidos, introduzimos no Capítulo 3, no contexto de problema de Stokes, as dificuldadas numéricas associadas ao método de Galerkin em problemas de fluidos e simulamos em sucesso alguns escoamentos lentos através de formulações finitos para estabilizadas. No capítulo 4, propomos uma nova formulação de elementos finitos para a equação da energia, mais precisamente para o modelo da advecção-difusão do calor. Graças a um novo desenho do parâmetro de estabilidade T, o qual permite adicionar difusão às regiões advectivas e difusivas-dominadas do escoamento de maneira diferemciada, obtivemos um bom desempenho novo método mesmo em situações de altíssimo número de Péclet (10(2) menor que Pe menor que 10 e (6)), conforme ilustram os testes numéricos realizados. Coletando as experiências adquiridas com modelos lineares de Stokes e da advencção-difusão, nos foi possível propor, analisar o erro e testar dois novos métodos estabilizados para o problema de Navier-Stokes transiente. Construídos de maneira a herdar as boas características de estabilidade dos métodos propostos apresentam bom desempenho em escoamentos fortemente advectivos, bem como não necessitam atender a priori à condição de Baduska-Brezzi. Através de um algoritmo preditor/ multi-corretor de integração do termo inercial da equação de movimento, estes ,métodos foram capazes de de simular de maneira precisa escoamentos de interesse em Mecânica(400 menor que Re< menor que 500), captando escoamentos secundários, tais como recirculações de fluido. / [en] Stabilized methods for fluid problems are proposed and analysed with particular emphasis to the incompressible Navier-Stokes equations. We Begin in Chapter 2 introducing the balance equations of fluid Mechanics. Next. In Chapter 3, we discuss the numerical difficulties of the Galerkin method in fluids(in the contexto f the Stokes problem) and performance some succeful simulations of creeping flows, employing stabilized formulations. In Chapter 4, we propose a new finite element formulation for the energy equation, or more preciselly for the advective-diffusive model. Taking advantage of new design of the stability parameter T, which permits to add diffusion to advective and diffusive regions of the flow in a different way, we success to obtain a good performance of the new method in flows with very high Péclet numbers (10(2) lass than Pe lessa than 10(6)), as illustred at numerical testes performed. By collecting the Stokes and advective-diffusive experiences,it was possible to propose, analyse and test two new stabilized methods for the transient Navier-Stokes problem. These methods were built in a way to heritage the good characteristics showed by the stabilized methods introduced for the Stokes and adventive-diffusive models. The new methods propoposed have a good performance in high advective flows, besides there is no need to satisfy the Babuska-Brezzi condition. Employing a predictor/multi-corretor algorithm, we were able to simulate accruratly some useful flows(400 less than Re less than 500), such as fluid recirculations.

V-Th-Pb fractionation trends, and the associated variations in Pb-isotopes, provide important constraints on the nature, and age, of a wide range of geological processes. This thesis presents three detailed case studies from a carbonatite intrusive complex, lower crustal granulite xenoliths, and young volcanic rocks which represent a range of processes that fractionate V, Th and Pb. New major, trace element and Sr, Nd and Pb isotope results are presented for carbonatites and pyroxenites from the 130 Ma old Jacupiranga complex in southern Brazil. The data preclude simple models in which the Sr-Nd and Sr-Pb isotope arrays are the result of crustal contamination processes, or liquid immiscibility between the carbonatites and magmas similar to those from which the pyroxenites crystallised. The initial Sr, Nd and Pb isotope ratios in the Jacupiranga complex are similar to those in the Parana high-Ti basalts and to the oceanic basalts of the Walvis Ridge and Tristan da Cunha, and were apparently inherited from the mantle source regions associated with incipient magmatism of the Tristan da Cunha hotspot and the opening of the South Atlantic. Most carbonatites have high V/Pb and low Rb/Sr ratios and infiltration and/ or metasomatism by such melts is one process that may be responsible for the negative correlation of U/Pb and Rb/Sr inferred for the source of certain oceanic basalts such as Tristan da Cunha. Correlations between trace and major elements in mostly mafic granulite xenoliths from southern Africa probably result from magmatic processes such as fractional crystallisation and crystal accumulation. From Pb and Nd isotope systematics it can be inferred that the northern Lesotho xenoliths are Proterozoic in age, whereas Cape province xenoliths appear to have been fonned in the Archaean and to have had their Nd isotopes reset in the Proterozoic. Most Pb isotope ratios from the granulites xenoliths are unradiogenic relative to the Geochron, which indicates relatively low V /Pb ratios in the later parts of their histories. The correlation between Pb isotope ratios and K₂O/A1₂O₃ in the granulites from Markt is considered to reflect magmatic control of the V /Pb fractionation. The Archaean, and some of the younger mantle derived rocks on the Kaapvaal craton, plot on similar Pb isotope trends. It is argued that segments of the crust and uppennost mantle beneath southern Africa stabilised together in the Archaean, and that both were remobilised in subsequent magmatic and orogenic events. Volcanic rocks in the Northland-Auckland peninsula, New Zealand, range from silica-undersaturated basanites to tholeiites and andesites. Although all the volcanic fields are in intraplate settings, two types of mantle source enrichment can be recognised. One is subduction-related and characterised by high Sr and low Nd isotope ratios and negative Nb anomalies. The other type has geochemical features characteristic of intraplate enriched mantle sources with Sr and Nd isotope ratios and Nb/Ba, Ba/La, similar to HIMV OIB, which has been attributed to the deep recycling of oceanic crust. The differences in Pb isotopes between the two mantle sources, i.e. higher /lB/4 and 7/4, but lower ²⁰⁶Pb/²⁰⁴Pb in the subduction-related material than in the inferred HIMU source, indicate that V/Pb in shallow recycled crustal material tend to be lower than in the deeper recycled material. These case studies confirm that (i) metasomatism by small degree melts can have significant effects on mantle trace element characteristics, (ii) the lower crust is a relatively low 11 environment and crystal accumulation may be an important mechanism in the fractionation of Th and U from Pb, cUld (iii) incorporation of recycled crustal material at different levels can result in different V-Th-Pb fractionation and so, with time, different Pb isotope ratios.

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Talmy (1975, 1985, 1991 and 2000b) studies Motion events encoded by verbs from the perspective of lexicalisation(T). Talmy (2000b) proposes six basic semantic elements to describe Motion events; they are Figure, Motion, Path, Ground, Manner, and Cause. For example, in the sentence He entered the room, enter is the main verb and encodes Motion “move” and Path “into”. So the main verb encodes the Path information. Such phenomena are very common in Spanish; however, in English and in Chinese Path is usually expressed by satellites, a category of surface element. Enter is exceptional in English. Although it is a word in English it was borrowed from French. The surface elements which encode the Path information determine a language’s type. For example, if Path is encoded by main verbs in language A, then this language A is a verb-framed language; if Path is typically expressed by satellites in language B, then language B is a satellite-framed language. These are the two most widespread types of languages in this typology. According to Talmy, English is a satellite-framed language (S-framed language); Spanish a verb-framed language (V-framed language); and Chinese a satellite-framed language. Slobin (1996, 1997, 2002, 2004 and 2006) argues that Chinese is an equipollent-framed language (E-framed language), a third language type he added to Talmy’s typology. The evidence for this is the serial verb construction (SVC) in Chinese. SVCs can be briefly defined as a syntactic pattern where two or more verbs are used together to express a single conceptual event and there are no markers of subordination and coordination. Slobin uses feī chū (fly exit) as an example of the SVC and he insists that feī (fly) and chū (exit) share the same grammatical status and are equal to each other in that neither of them can be omitted for a complete expression of the event of flying out. The first verb encodes the Manner information and the latter one expresses the Path information. Omitting either part, the expression is ungrammatical. Having briefly reviewed these two models of language typology, many questions have arisen. Is it necessary to have a third language type to account for Chinese? Or is Chinese an Eframed language or a S-framed language? What is the language typology of Chinese? This is the main research question I aim to answer in this thesis. The main question concerns the nature of Chinese SVCs. In my thesis, I discuss the features of Chinese SVCs as preparation for a working definition of SVC for my empirical work to collect the SVC data from the Lancaster Corpus of Mandarin Chinese (LCMC). I show that the components in Chinese SVCs are not equal in semantics. There are constraints on the positions for different semantic parameters. In addition, the surface forms of components for SVCs do not share equal status for the asymmetrical SVCs. This further shows that components within Chinese SVCs are not in equal grammatical status. My data shows that Path can be encoded by main verbs as well as by satellites in Chinese. Having illustrated that Chinese SVC is not evidence for Chinese to be an E-framed language, then, is Chinese a S-framed language similar to English or a V-framed language like Spanish? Özçalışkan (2004) claims that Path verbs, verbs encoding [Motion + Path], is a closed class. How many Path verbs are there in Chinese and are these Path verbs comparable with those in English and in Spanish? I give a comprehensive list of Chinese Path verbs and then focus on some of them to track the process of the lexicalisation(T). I found that there are no significant differences in number for the 13 types of Path verbs in Chinese, English and Spanish and that the lexicalised(T) Path is comparable. These findings indicate that Chinese uses both main verbs and satellites to express the Path information in motion events. Additionally, the grammaticalization trend of Chinese Path verbs and the shift from independent Path verbs into Path satellites and grammatical relation markers also show that Chinese is not part of any of the parallel system, the split system, or the intermixed system for expressing motion events. Chinese is in the transferring period from a S-framed language to a V-framed language.