Pneumonia as it Affects Young Adults: The Predisposing Factors

Abstract Not Provided

Geology and tectonic evolution of the Western Approaches Trough

Maps/charts relating to this thesis have not been filmed, please apply direct to the issuing universityAvailable from British Library Document Supply Centre- DSC:D77549 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Origin and petrophysical log response of overpressures in the Baram Delta province, Brunei.

The ‘window’ of safe mud weights between pore pressure and fracture pressure is narrower in overpressured sediments than in normally pressured sediments. This ‘window’ also controls the maximum buoyancy pressure, and hence the maximum height of hydrocarbon columns. Therefore, accurate pore pressure prediction is of critical importance for hydrocarbon exploration. Accurate pore pressure prediction is especially important in the rapidly depositing (3000 m/Ma) Tertiary Baram Delta Province where all economic fields exhibit overpressures, often of high magnitude and with narrow transition zones. A database of pore pressure information was compiled for 157 wells in 61 fields throughout Brunei. Overpressures are observed in 54 fields both in the inner shelf deltaic sequences and the underlying pro-delta shales. Porosity-vertical effective stress plots from 31 fields reveal that overpressures are primarily generated by disequilibrium compaction in the pro-delta shales, but have been vertically transferred into the inner shelf deltaic sequences.Sediments overpressured by disequilibrium compaction exhibit different physical properties to those overpressured by vertical transfer and hence, different pore pressure prediction strategies need to be applied in the prodelta shales and inner shelf deltaic sequences. Sonic and density log data detects overpressures generated by disequilibrium compaction and pore pressures are accurately predicted using an Eaton exponent of 3.0. Sonic log data detects vertically transferred overpressures, even in the absence of a porosity anomaly, and pore pressures are reasonably predicted using an Eaton exponent of 6.5

Utility of B-type natriuretic peptide in predicting medium-term mortality in patients undergoing major non-cardiac surgery

We assessed the ability of pre-operative B-type natriuretic peptide (BNP) levels to predict medium-term mortality in patients undergoing major noncardiac surgery. During a median 654 days follow-up 33 patients from a total cohort of 204 patients (16%) died. The optimal cut-off in this cohort, determined using a receiver operating characteristic curve, was >35pg.mL-1. This was associated with a 3.47-fold increase in the hazard of death (p=0.001) and had a sensitivity of 70% and a specificity of 68% for this outcome. These findings extend recent work demonstrating that BNP levels obtained before major noncardiac surgery can be used to predict peri-operative morbidity, and indicate that they also forecast medium-term mortality.This work was supported by a grant from TENOVUS Scotland. The Health Services Research Unit is core-funded by the Chief Scientists Office of the Scottish Executive Health Department.Peer reviewedAuthor versio

Carbon dioxide (CO2 ) geological storage potential of the Bass Basin

AbstractEvaluation of the Bass Basin’s suitability for CO2 storage has been undertaken by analysing several key basin analysis elements, including seal capacity and integrity, reservoir quality, petroleum systems modelling and CO2 migration and storage modelling.Seal geometry, capacity and integrity of the Demons Bluff Formation has been investigated to evaluate CO2 containment in the basin. The study revealed good to excellent sealing capacity for the Demons Bluff Formation and for the intraformational seals within the Eastern View Group (EVG). Faults traversing the reservoir/regional seal boundary, as well as faults intersecting the top of the regional seal were evaluated for future risk of reactivation. There is some risk of reactivation associated with N-E striking faults, fortunately these faults are mostly confined to the margins of the basin.Reservoirs of the Upper EVG generally have high porosity and permeability. Hydrocarbon migration and accumulation in the basin were simulated, to examine the petroleum potential of specific reservoirs within the basin. Migration models suggest most of the trapped hydrocarbons occur in the reservoir sands of the Middle EVG. Reservoirs of the Upper EVG were have received little hydrocarbon charge, except for the northeastern part of the basin.CO2 migration paths within reservoirs of the Upper EVG were simulated based on a buoyancy driven migration model. Migration pathways within the Upper EVG and CO2 accumulations under the regional seal were identified. In addition, total available pore volumes for CO2 storage associated with structural traps was calculated at >2 billionm3

Contemporary stress orientations in the Faroe-Shetland region

The Faroe-Shetland Region (FSR) of the NE Atlantic continental margin contains a number of complexly structured Mesozoic-Palaeogene-age rift basins, but in comparison to the contiguous British Isles and North Sea Basin, the state of crustal stress in the FSR is poorly understood. The orientation of maximum horizontal compressional stress (σHmax) across most of NW Europe is ~NW-SE, which is considered to be controlled by forces acting at the plate boundaries. We have determined 16 B-D quality σHmax orientations based on borehole breakouts interpreted in petroleum wells, and define three distinct stress provinces within the FSR. Stress orientations in the NE are ~NW-SE, consistent with the regional pattern of stresses in NW Europe and local neotectonic structural trends. However, contemporary stress orientations in the central and SW of the FSR exhibit short-wavelength (distances <10-50 km) variation, with NE-SW, N-S and E-W orientations that are parallel or sub-parallel to underlying structural trends. This variation is interpreted in terms of stress deflections towards weak faults that downthrow the Mesozoic-Cenozoic sedimentary successions against basement highs. These local-scale sources are superposed on a background ~WNW-ESE σHmax orientation that is controlled by both plate boundary forces and regional-scale sources of stresses

Simulation of a power electronic conversion system with short-term energy storage for actively controlled wave energy converters

A simulation study is conducted to assess the feasibility of a Wave Energy Converter Power Electronic Converter architecture to achieve a four quadrant torque demand resulting from an active control strategy. The system consists of four induction generators controlled by three phase inverters, a DC bus with short term energy storage provided by supercapacitors and batteries, and an active rectifier to control the DC bus voltage and provide AC power to the grid. The components are realistically modelled and it is shown that the torque and speed requirements of the active control strategy can be achieved and that the electrical energy storage can provide required reactive power on a wave-by-wave time scale and longer term energy supply during a lull in wave excitation. The WaveSub WEC is used as a target device in order to make a meaningful study with realistic inputs. However the architecture of the PEC system is applicable to any device with a bi-directional rotary PTO requiring four-quadrant active control at the generators. Furthermore the PEC architecture and simulation model are readily expandable to arrays of wave energy converters.</p

Simulation of a power electronic conversion system with short-term energy storage for actively controlled wave energy converters

A simulation study is conducted to assess the feasibility of a Wave Energy Converter Power Electronic Converter architecture to achieve a four quadrant torque demand resulting from an active control strategy. The system consists of four induction generators controlled by three phase inverters, a DC bus with short term energy storage provided by supercapacitors and batteries, and an active rectifier to control the DC bus voltage and provide AC power to the grid. The components are realistically modelled and it is shown that the torque and speed requirements of the active control strategy can be achieved and that the electrical energy storage can provide required reactive power on a wave-by-wave time scale and longer term energy supply during a lull in wave excitation. The WaveSub WEC is used as a target device in order to make a meaningful study with realistic inputs. However the architecture of the PEC system is applicable to any device with a bi-directional rotary PTO requiring four-quadrant active control at the generators. Furthermore the PEC architecture and simulation model are readily expandable to arrays of wave energy converters.</p

Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting

Background: An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization. Methods: Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality. Results: The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P 3.36). Conclusion: An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.Peer reviewedAuthor versio