Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2002. / "Joint Program in Oceanography/Applied Ocean Science and Engineering."--Cover. "June 2002." Funding was provided by the National Aeronautics and Space Administration under grant NAG5-7194, and by the Office of Naval Research under grant N00014-98-10881. Includes bibliographical references (p. 134-138).

Proefschrift van geaggregeerde-University catholique de Louvain. / Summary in Dutch. Bibliography: p. 147-160.

Thesis (Ph. D.)--Stony Brook University, 2003. / Includes bibliographical references (leaves 81-82).

Thesis (doctoral)--Universität Trier, 2004. / Also available via the internet in PDF or HTML formats.

Cette thèse s'attache à caractériser l'évolution dans le temps et l'espace des circulations de fluides le long des failles. Une approche multidisciplinaire et multi-échelle a été mise en place sur un exemple naturel dans la région du plateau du Colorado (Utah): du terrain à la modélisation et de la proche-surface au bassin. L'étude des minéralisations en proche surface et leur lien avec le transfert le long des failles a été effectuée sur des travertins récents. L'analyse isotopique et la datation U/Th des veines de travertins révèle des cycles de circulation de fluides enrichis en CO2 et de précipitation épisodiques de carbonates de calcium (travertin) correspondant à des cycles saisonniers ou climatiques (annuels et centennals) ainsi qu'à des cycles qui s'apparentent à des cycles sismiques de l'ordre du millier d'années. Ces données permettent de calibrer le volume de CO2 qui a fuit par la faille. Des zones de paléo-circulation, témoins de l'activité des failles sur le long-terme, sont observées sous forme de blanchiment chimique ("bleaching") des grès à l'affleurement, et ont été étudiées à l'échelle du bassin. Deux épisodes principaux de circulation de fluides le long des failles ont été distingués : une première circulation durant l'enfouissement maximum puis une seconde circulation le long des réservoirs et des failles, qui est reliée à des phénomènes tectoniques régionaux, compemporains de la remontée du Plateau du Colorado. La dernière circulation s'est découpée en plusieurs pulses avec des circulations de fluides de différente nature (tels que des saumures, des fluides riches en hydrocarbures ou en CO2) au cours du temps et le long des failles. / This work aims to characterise fluid flow along faults in time and space. Multi-disciplinary and multi-scale investigations of a natural analogue have been carried out in the Colorado Plateau area (Utak, USA), from fieldwork to numerical modeling. The study of Quaternary travertine calibrated the near-surface mineralization and their relationship with the faults. Stable Isotope measurements and U/Th datings of travertine veins revealed episodic cycles of CO2-fluid circulation and related calcium carbonate precipitation (travertine). These cycles may be linked with seasonal or climatic cycles (annual and centennial) and also with seismic cycles of millennial duration. Based on the obtained data, escaping CO2 volumes from the fault zone, with time have been calibrated. Chemical bleaching of the outcropping sandstones, linked with fluids paleo-circulation at depth, has been characterized at basin scale. Two main circulation events have been distinguished: a first circulation contemporaneous to maximum burial and a second along-reservoirs and faults circulation that could be linked with later regional tectonic events, contemporaneous of Colorado Plateau rusing. Pulses of different fluids (such as brines, fluids enriched in hydrocarbons or CO2) are linked in time and space with the last circulation.

The effect of hypoxemia on coronary autoregulation was investigated in nine anesthetized, open-chest dogs. The anterior descending coronary artery (LAD) was cannulated and perfused with normoxic arterial blood and with moderately hypoxic blood (0₂ content = 10 + 1 ml 0₂ /dl). LAD blood flow was measured as perfusion pressure was varied from 140 to 40 mmHg. At perfusion pressures at and above 40 mmHg, hypoxemia significantly increased LAD flow. During normoxia, the autoregulatory closed-loop gain (Gc) was significantly greater than zero at perfusion pressures from 60 to 120 mmHg. During hypoxemia, Gc was greater than zero only at perfusion pressures from 80 to 100 mmHg. During hypoxemia, LAD blood flow increased sufficiently to maintain oxygen delivery and consumption constant, but the range and potency of autoregulation was attenuated.

No description available.

A long and gradual transition between the summer and winter oceanic regimes was observed off Oregon during the autumn of 1980. Hydrographic sections and a single current meter mooring between August and December show the ocean possessed characteristics during fall that have not been observed during other seasons: a slow ascension of the poleward undercurrent and the appearance of a large bottom boundary layer. The decay of summer's southward surface flow was achieved by a series of modest northward wind events during late summer as the effects of southward winds were becoming diminished. The northward wind events had progressively stronger influence on surface currents. The barotropic current fluctuations that are a signature of the summer regime continued during the transitional period. The weekly-to-monthly averaged flow was barotropic during much of the transition. Hydrographic sections and time series of alongshore current shear and temperature show that the leveling of the frontal layer was achieved gradually over a two month time scale. The winter regime was established during eleven days of continuous northward wind stress in early November. / Graduation date: 1987

No description available.

No description available.