Applications of aerospace technology to petroleum extraction and reservoir engineering

Through contacts with the petroleum industry, the petroleum service industry, universities and government agencies, important petroleum extraction problems were identified. For each problem, areas of aerospace technology that might aid in its solution were also identified, where possible. Some of the problems were selected for further consideration. Work on these problems led to the formulation of specific concepts as candidate for development. Each concept is addressed to the solution of specific extraction problems and makes use of specific areas of aerospace technology

The evolution of the Gulf of Corinth (Greece): an aftershock study of the 1981 earthquakes

A preliminary study of the aftershocks of three earthquakes that occurred near to Corinth (Greece) in 1981 is combined with observations of the morphology and faulting to understand the evolution of the Eastern Gulf of Corinth. The well located aftershocks form a zone 60km long and 20km wide. They do not lie on the main fault planes and are mostly located between the north-dipping faulting on which the first two earthquakes occurred and the south-dipping faulting associated with the third event. A cluster of aftershocks also lies in the footwall of the eastern end of the south-dipping fault of the third event

Near-surface structure of the North Anatolian Fault zone from Rayleigh and Love wave tomography using ambient seismic noise

We use observations of surface waves in the ambient noise field recorded at a dense seismic array to image the North Anatolian Fault zone (NAFZ) in the region of the 1999 magnitude 7.6 Izmit earthquake in western Turkey. The NAFZ is a major strike-slip fault system extending ∼1200&thinsp;km across northern Turkey that poses a high level of seismic hazard, particularly to the city of Istanbul. We obtain maps of phase velocity variation using surface wave tomography applied to Rayleigh and Love waves and construct high-resolution images of S-wave velocity in the upper 10&thinsp;km of a 70&thinsp;×&thinsp;30&thinsp;km region around Lake Sapanca. We observe low S-wave velocities (&lt;2.5&thinsp;km&thinsp;s−1) associated with the Adapazari and Pamukova sedimentary basins, as well as the northern branch of the NAFZ. In the Armutlu Block, between the two major branches of the NAFZ, we image higher velocities (&gt;3.2&thinsp;km&thinsp;s−1) associated with a shallow crystalline basement. We measure azimuthal anisotropy in our phase velocity observations, with the fast direction seeming to align with the strike of the fault at periods shorter than 4&thinsp;s. At longer periods up to 10&thinsp;s, the fast direction aligns with the direction of maximum extension for the region (∼45∘). The signatures of both the northern and southern branches of the NAFZ are clearly associated with strong gradients in seismic velocity that also denote the boundaries of major tectonic units. Our results support the conclusion that the development of the NAFZ has exploited this pre-existing contrast in physical properties.</p

Moderate Champagne consumption promotes an acute improvement in acute endothelial-independent vascular function in healthy human volunteers

Epidemiological studies have suggested an inverse correlation between red wine consumption and the incidence of CVD. However, Champagne wine has not been fully investigated for its cardioprotective potential. In order to assess whether acute and moderate Champagne wine consumption is capable of modulating vascular function, we performed a randomised, placebo-controlled, cross-over intervention trial. We show that consumption of Champagne wine, but not a control matched for alcohol, carbohydrate and fruit-derived acid content, induced an acute change in endothelium-independent vasodilatation at 4 and 8 h post-consumption. Although both Champagne wine and the control also induced an increase in endothelium-dependent vascular reactivity at 4 h, there was no significant difference between the vascular effects induced by Champagne or the control at any time point. These effects were accompanied by an acute decrease in the concentration of matrix metalloproteinase (MMP-9), a significant decrease in plasma levels of oxidising species and an increase in urinary excretion of a number of phenolic metabolites. In particular, the mean total excretion of hippuric acid, protocatechuic acid and isoferulic acid were all significantly greater following the Champagne wine intervention compared with the control intervention. Our data suggest that a daily moderate consumption of Champagne wine may improve vascular performance via the delivery of phenolic constituents capable of improving NO bioavailability and reducing matrix metalloproteinase activity

Strain localization by shear heating and the development of lithospheric shear zones

Analogue and numerical models show that strong or weak domains in a deforming ductile material cause stress concentrations that may promote strain localization. Such domains commonly occur in the lithosphere through variations in composition or mineral fabric. Here we use a 2D plane-stress, non-Newtonian, viscous model to explore how strain localization develops from an initial isolated weak inclusion. We use a temperature-dependent rheological law for which the material weakens as a result of work done by shear converted to heat. The progress of strain localization follows a power-law growth that is strongly non-linear and may be regarded as an instability. Although this localization mechanism is ultimately limited by thermal diffusion, this parametrization permits a robust criterion for the conditions in which localized shear zones can form within the lithosphere. Shear zones in the lower crust are typically depicted as the downward continuation of faults. We argue that the depth-extent of narrow shear zones within the lithosphere is limited by the stability criteria that we infer from 2D numerical experiments. When applied to the rheological laws for common lithospheric minerals, the combination of temperature and stress-dependence provides a direct means of predicting the depth below which the localization instability does not occur. For an olivine based rheology, the maximum depth at which rapid localization is expected is in the range of ~20 to 60 km, depending on heat flow, strain-rate and water fugacity. We apply our calculations to two major continental strike-slip zones, the San Andreas Fault and North Anatolian Fault, and compare our predicted maximum localization depths with published seismological images. Strain localization in the lower crust requires a dry rheology comparable to plagioclase. Observations that imply localized strain in the uppermost mantle beneath these fault zones are consistent with the localization criteria and the rheological properties of dry olivine

Dating of the oldest continental sediments from the Himalayan foreland basin

A detailed knowledge of Himalayan development is important for our wider understanding of several global processes, ranging from models of plateau uplift to changes in oceanic chemistry and climate(1-4). Continental sediments 55 Myr old found in a foreland basin in Pakistan(5) are, by more than 20 Myr, the oldest deposits thought to have been eroded from the Himalayan metamorphic mountain belt. This constraint on when erosion began has influenced models of the timing and diachrony of the India-Eurasia collision(6-8), timing and mechanisms of exhumation(9,10) and uplift(11), as well as our general understanding of foreland basin dynamics(12). But the depositional age of these basin sediments was based on biostratigraphy from four intercalated marl units(5). Here we present dates of 257 detrital grains of white mica from this succession, using the Ar-40-(39) Ar method, and find that the largest concentration of ages are at 36-40 Myr. These dates are incompatible with the biostratigraphy unless the mineral ages have been reset, a possibility that we reject on the basis of a number of lines of evidence. A more detailed mapping of this formation suggests that the marl units are structurally intercalated with the continental sediments and accordingly that biostratigraphy cannot be used to date the clastic succession. The oldest continental foreland basin sediments containing metamorphic detritus eroded from the Himalaya orogeny therefore seem to be at least 15-20 Myr younger than previously believed, and models based on the older age must be re-evaluated

What Do We Know About Contracting Out in the United States? Evidence from Household and Establishment Surveys

A variety of evidence points to significant growth in domestic contracting out over the last two decades, yet the phenomenon is not well documented. In this paper, we pull together data from various sources to shed light on the extent of and trends in domestic outsourcing, the occupations in which it has grown, and the industries engaging in outsourcing for the employment services sector, which has been a particularly important area of domestic outsourcing. In addition, we examine evidence of contracting out of selected occupations to other sectors. We point to many gaps in our knowledge on trends in domestic outsourcing and its implications for employment patterns and to inconsistencies across data sets in the information that is available. We recommend steps to improve data in this area

Intracontinental Orogeny Enhanced by Far-field Extension and Local Weak Crust

The accommodation of intraplate stresses in preexisting weak regions of plate interiors is here investigated using thin viscous sheet numerical models. The intraplate stresses are governed by multicomponent and multidirectional stresses originating at plate boundaries. The modeled scenarios mimic plate boundary conditions during the intraplate Alice Springs Orogeny (ASO), central Australia, and include (1) a northwest‐southeast zone of weak lithosphere within strong continental blocks to the north and southand (2) a principal south directed stress condition at the northern boundary that causes minor clockwise rotation of the northern block. Alternative tectonic environments are investigated in additional models that include (1) secondary compressional or extensional stresses acting at the eastern boundary, representing the temporally variable stress conditions during the Tasmanides Orogeny, and (2) an eastern wedge‐shaped zone of rheologically weak lithosphere, mirroring rift fill of the Irindina subbasin. Our results highlight that a low angle between major crustal features (e.g., orogenic elongation and preexisting regional structures) and the principal transmitted stresses is highly relevant in the concentration of elevated levels of differential stress and subsequent localization of deformation in plate interiors. Secondary stresses orthogonal to the principal acting stresses may introduce effects that explain the episodic orogenic activity in the case of the ASO. The combination of secondary extensional stresses at the eastern boundary of Australia and weak lithosphere of the preexisting Irindina subbasin strongly influences the observed spatial strain intensity, localization, and kinematics of deformation during the ASO

Identification, replication and characterization of epigenetic remodelling in the aging genome:A cross population analysis

Aging is a complex biological process regulated by multiple cellular pathways and molecular mechanisms including epigenetics. Using genome-wide DNA methylation data measured in a large collection of Scottish old individuals, we performed discovery association analysis to identify age-methylated CpGs and replicated them in two independent Danish cohorts. The double-replicated CpGs were characterized by distribution over gene regions and location in relation to CpG islands. The replicated CpGs were further characterized by involvement in biological pathways to study their functional implications in aging. We identified 67,604 age-associated CpG sites reaching genome-wide significance of FWE