O objetivo deste trabalho é apresentar a teoria fundamental da análise de massas de água baseada nas características temperatura e salinidade, e a sua aplicação, em grande escala, às águas que circulam na troposfera oceânica e na camada intermediária da região oeste do Oceano Atlântico Sul Tropical, ao longo da costa brasileira. A região estudada está delimitada pelas latitudes de 7°S e de 20°S. Determinouse que a área de geração da camada de salinidade máxima, encontrada a 100 m de profundidade nessa região, está situada ao sul de 15°S, extendendose até as proximidades de 20°S. A partir de modelos estacionários para o estudo da mistura de massas de água foi possível avaliar o coeficiente vertical de difusão turbulenta, para o núcleo da Água Intermediária Antártica, que está compreendido entre 5 cm2 .s-1 e 15 cm2 .s-1 Na Água Central do Atlântico Sul encontraramse os valores: 20 cm2 .s-1 e 13 cm2 .s-1, para os coeficientes verticais de condutividade térmica turbulenta e de difusão turbulenta de sal, respectivamente. O triângulo de contração do volume específico na mistura vertical, permitiu estudar a influência desse fenômeno na mistura da Água Intermediária Antártica com as massas de água que a envolvem. O valor máximo desse parâmetro foi encontrado na interface entre essa última massa de água e a Água Central do Atlântico Sul ( - 3,2.10-4 cm3 .g-1). / The purpose of this work is to present the fundanental theory of water masses analysis, based on the teraperature and salinity properties, and its utilization in great scale to waters of the oceanic troposphere and of the intermediate layer of the west region of the South Tropical Atlantic Ocean along the Brazilian coast. The region under study is limited by latitude 7°S and 20°S. It was deterinined that the source area of hi salinity layer, which is found at 100 m in depth in this region, is located to the south of 15°S, extending as far as 20°S. Based on stationary models for the study of water nesses mixture, it was possible to estimate the vertical coefficient of turbulent diffusion, for the core of Antarctic Intermediate Water, which is between 5 cm2 .s-1 and 15 cm2 .s-1. In the South Atlantic Certral Water values of 20 cm2 .s-1 and 13 cm2 .s-1 are found for the vertical coefficients of turbulent heat conduction and turbulent salinity diffusion, respectively. The triangle of the specific volume contraction in the vertical mixing permitted the study of the influence of this phenomenon on the mixture of the Antarctic Intermediate Water and the water masses that envolves it. The greatest value of this parameter was found in the interface of the latter and the South Atlantic Central Water ( - 3,2.10-4 cm3 .g-1).

O objetivo deste trabalho é apresentar a teoria fundamental da análise de massas de água baseada nas características temperatura e salinidade, e a sua aplicação, em grande escala, às águas que circulam na troposfera oceânica e na camada intermediária da região oeste do Oceano Atlântico Sul Tropical, ao longo da costa brasileira. A região estudada está delimitada pelas latitudes de 7°S e de 20°S. Determinouse que a área de geração da camada de salinidade máxima, encontrada a 100 m de profundidade nessa região, está situada ao sul de 15°S, extendendose até as proximidades de 20°S. A partir de modelos estacionários para o estudo da mistura de massas de água foi possível avaliar o coeficiente vertical de difusão turbulenta, para o núcleo da Água Intermediária Antártica, que está compreendido entre 5 cm2 .s-1 e 15 cm2 .s-1 Na Água Central do Atlântico Sul encontraramse os valores: 20 cm2 .s-1 e 13 cm2 .s-1, para os coeficientes verticais de condutividade térmica turbulenta e de difusão turbulenta de sal, respectivamente. O triângulo de contração do volume específico na mistura vertical, permitiu estudar a influência desse fenômeno na mistura da Água Intermediária Antártica com as massas de água que a envolvem. O valor máximo desse parâmetro foi encontrado na interface entre essa última massa de água e a Água Central do Atlântico Sul ( - 3,2.10-4 cm3 .g-1). / The purpose of this work is to present the fundanental theory of water masses analysis, based on the teraperature and salinity properties, and its utilization in great scale to waters of the oceanic troposphere and of the intermediate layer of the west region of the South Tropical Atlantic Ocean along the Brazilian coast. The region under study is limited by latitude 7°S and 20°S. It was deterinined that the source area of hi salinity layer, which is found at 100 m in depth in this region, is located to the south of 15°S, extending as far as 20°S. Based on stationary models for the study of water nesses mixture, it was possible to estimate the vertical coefficient of turbulent diffusion, for the core of Antarctic Intermediate Water, which is between 5 cm2 .s-1 and 15 cm2 .s-1. In the South Atlantic Certral Water values of 20 cm2 .s-1 and 13 cm2 .s-1 are found for the vertical coefficients of turbulent heat conduction and turbulent salinity diffusion, respectively. The triangle of the specific volume contraction in the vertical mixing permitted the study of the influence of this phenomenon on the mixture of the Antarctic Intermediate Water and the water masses that envolves it. The greatest value of this parameter was found in the interface of the latter and the South Atlantic Central Water ( - 3,2.10-4 cm3 .g-1).

In chapter 3 of our paper we present equations of motion for continuous mass distribution subject to hydrodynamic forces in their most general form. We start with equations for discrete mass particles and then transform the equations so that it is appropriate for a continuous mass distribution. As we do that, new forms of interactions are generated and we successfully include these interactions, using the propagator theory, in the general form of our hydrodynamic equations for continuous mass distributions. We also took a deeper mathematical description of rotational flows. We were able to explain many physical phenomena successfully by our treatment of rotational flows in a more concrete and simple way, for example, the phenomenon of ripples that appear on ocean beaches and in desert sands. In chapter 4 we study the behavior of water surfaces. A liquid drop of water takes on a spherical shape because of the phenomenon of surface tension. A physical model based on the arrangement which the water molecules have on the surface is introduced to explain the above phenomenon. A mathematical model, as well as the physical model mentioned above, is introduced to describe the kind of forces involved on a wavy surface. The equations obtained describe the phenomenon of surface tension on a microscopic level very successfully. In chapter 5 we apply the results of chapters 3 and 4 to get an equation that gives a critical dynamical value which govern the interactions between the moving fluid and the dust particles residing on the ground. / Graduation date: 1996

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Supervised by Nelson Hogg. Includes bibliographical references (leaves 108-109).

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982. / Bibliography: p. 139-140.

There is now convincing evidence that the Standard Model of electroweak and strong interactions is not the end of the story but only a low energy effective theory. In particular, new flavour physics is required to explain the fermion mass spectrum. Most of the proposed extensions of the Standard Model fail to meet this criterion. We may hope that the LHC or some future colliders could help to clarify the situation by discovering new particles or spotting some unexpected events. In the meantime, more precise measurements of masses and mixing parameters could also play an important role. In this work, we do not aim at finding a new mechanism that could explain this spectrum, but we rather assume that fermion masses and mixings are calculable in a yet-to-be-found more fundamental theory. Our goal is to glean as much information as possible from the observed fermion masses and mixings in order to find some hidden structures that could significantly lower the number of free parameters and help us to get some clues about what could be this fundamental theory. We analyse first the various parametrizations of the flavour mixing and single out a specific decomposition. The parameters of this decomposition can be independently and accurately computed if we impose some simple textures to the Yukawa couplings. We propose then a straightforward combination of these interesting textures which reproduces quite well the observed quark flavour mixing. We study then the properties of a successful mass relation for the charged leptons. We propose some generalizations of this relation in order to be valid also for the neutrinos and the quarks. One of them successfully combines the masses and mixings while another one describes the lepton masses via an accurate geometric description. Hopefully, these two studies lead to similar conclusions and allow us to speculate on some interesting properties for new flavour physics.

Esta investigación realiza por primera vez una revisión global del desarrollo turístico en Catalunya en los dos últimos siglos, y entre otros elementos presenta como novedad las series históricas de la oferta y demanda turística del Principado en su período de mayor crecimiento, el del turismo de masas o fordista.En el trabajo se demuestra la importancia de la actividad en la economía y la sociedad catalanas así como en la creación de una imagen del territorio. A lo largo del análisis se plantean las ventajas que la actividad ha reportado pero también los inconvenientes que se han ido detectando en el mismo. A su vez, se realiza una reflexión acerca de los posibles escenarios futuros de la actividad teniendo en cuenta el actual tránsito hacia una nueva etapa de la actividad, la postfordista. Finalmente, se presenta un modelo global que agrupa el desarrollo por fases del destino con los cambios paradigmáticos de la actividad y que se entiende puede ser de ayuda para comprender el pasado, presente y las posibles trayectorias futuras del turismo. / This investigation makes, for the first time, a global revision of the tourist development in Catalonia in the last two centuries. Among other contributions, this thesis presents new tourist supply and demand historical series for this region in its period of greater growth, that is "mass tourism" or "fordist tourism".The work demonstrates not only the importance of the tourist activity in the Catalan economy and society but also in building an image of the territory. Throughout the analysis it is unfolded the advantages that tourism has brought to the region and it is detected the disadvantages attached to the development of this activity. In addition, the study discusses possible future scenarios of tourism taking in to account the current shift towards a new stage of the activity, the "postfordist stage". Finally, it is shown a global model presenting the development by phases of the tourist destination. This model is associated with the paradigmatic changes of the activity and that can be of aid to understand the past, present and possible future trajectories of tourism.

Thesis (Ph. D.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and the Woods Hole Oceanographic Institution), 2003. / Includes bibliographical references (p. 145-148).

The work presented in this thesis investigates the evolution of starforming galaxies over the last ten billion years. This time period encompasses nearly three-fourths of the age of the Universe, when a substantial fraction of the total stellar mass forms, and the sites of active star formation shift to lower-mass galaxies. The first study presented here combines galaxies from the spectroscopic datasets of the FORS Deep Field and the MUNICS Survey and provides the first significant investigation of the specific star formation rate (SSFR; star formation rate [SFR] per unit stellar mass) over a wide range of stellar masses and redshifts (reaching redshift z = 1:5). From [OII]-derived SFRs, we find that low-mass galaxies have higher SSFRs all the way to z = 1:5, implying that star formation contributes progressively more to the growth of stellar mass in low-mass galaxies than in high-mass galaxies. In the follow-up to this study, we combine several near-infrared-selected samples to create one of the largest collections of galaxies with spectroscopic redshifts and morphologies from Hubble Space Telescope images, to characterize the stellar mass build up in galaxies since z = 1:6. The primary data comes from the FORS Deep Field, the MUNICS Survey, the GOODS-South field as observed by the K20 survey and ESO, and the Sloan Digital Sky Survey as a local comparison sample. After bringing together extensive photometric and spectroscopic data sets from several publicly available surveys, we use identical methods to derive physical properties and investigate how galaxy populations evolve with time. Galaxy properties include stellar masses derived from multiwavelength photometry, star formation rates calculated from [OII][lambda]3726Å emission lines, metallicity, color, and SSFRs. We find that the reddest, yet actively star-forming, disk-dominated galaxy population present at z ~ 1:3, decreases in number by z ~ 0:3 during the same timeframe when the bluest quiescent, disk-dominated galaxy population increases in number. We confirm the previously identified morphological separation in the SSFR versus M[subscript asterisk] plane found for local samples and for galaxies at z = 0:7: bulge-dominated galaxies are more massive and have lower SSFRs. We extend this relation for the first time to z = 1:6, showing that galaxies with high SSFRs and diskdominated structures tend to shift to lower masses as redshift decreases. We identify an observed upper envelop in SSFR that lies roughly parallel to lines of constant SFR, decreases with time, and is unaffected by incompleteness among the samples. We apply common star formation histories (constant, ex ponential, and power law) to understand the evolving populations we see, but cannot simultaneously reproduce low-mass galaxies with high SSFRs and highmass galaxies with low SSFRs at all redshifts and over our full mass range. Current semi-analytic models attempt to understand the mass at which galaxies stop forming stars through connections to Active Galactic Nuclei feedback, gas consumption, declining galaxy merger rates and/or changes in the incoming cold gas supply, but none can explain the gradual and constant decline of star formation consistent among all galaxies below this mass. We suggest a possible resolution where star formation histories of galaxies are dependent on morphology, in addition to the growing evidence for lower mass galaxies to begin forming stars at later times, and with lower initial SFRs than the initial SFRs experienced at earlier times by higher mass galaxies. / text

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