731 research outputs found

    Thermal modelling of the Cheshire Basin using BasinModTM

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    The Cheshire Basin is a half-graben formed as one of a series of sedimentary basins during Permo-Triassic rifting. The Permo-Triassic infill of this basin may have been up to four or five kilometres thick prior to geologically recent erosion. The basin is flanked to the East and West by Carboniferous and older rocks. The succession in this region displays widespread uplift and erosion resulting from northward encroachment of the Variscan Front at the end of the Carboniferous. This report details the development of 1-D thermal models and integration to a 2-D model of the Cheshire Basin. BasinModTM (Platte River Software) has been used to model compaction and temperature through burial over geological time using a variety of datasets. The report considers the Cheshire Basin area through the Carboniferous to the present day, concentrating on the late Carboniferous Coal Measures where maturity data are available. Heat flow in this region was assumed to be generally high during the latest Carboniferous to early Permian. Modelled isotherms and maturity plots imply that the greatest temperatures attained in the productive Coal Measures occurred during Permian to Cretaceous burial in the basin centre, and during late Carboniferous to Permian time outside of the basin. The 1-D models imply that some Carboniferous Coal Measures reached the oil generation window. Minor oil stains and shows were found in some Cheshire Basin boreholes. However there does not appear to be a suitable trap to create a commercially viable reservoir. The BasinMod model results and this best practice report with accompanying checklist and guidelines are stored electronically for the DGSM

    Dynamical equations for high-order structure functions, and a comparison of a mean field theory with experiments in three-dimensional turbulence

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    Two recent publications [V. Yakhot, Phys. Rev. E {\bf 63}, 026307, (2001) and R.J. Hill, J. Fluid Mech. {\bf 434}, 379, (2001)] derive, through two different approaches that have the Navier-Stokes equations as the common starting point, a set of steady-state dynamic equations for structure functions of arbitrary order in hydrodynamic turbulence. These equations are not closed. Yakhot proposed a "mean field theory" to close the equations for locally isotropic turbulence, and obtained scaling exponents of structure functions and an expression for the tails of the probability density function of transverse velocity increments. At high Reynolds numbers, we present some relevant experimental data on pressure and dissipation terms that are needed to provide closure, as well as on aspects predicted by the theory. Comparison between the theory and the data shows varying levels of agreement, and reveals gaps inherent to the implementation of the theory.Comment: 16 pages, 23 figure

    Exploring dark matter microphysics with galaxy surveys

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    We use present cosmological observations and forecasts of future experiments to illustrate the power of large-scale structure (LSS) surveys in probing dark matter (DM) microphysics and unveiling potential deviations from the standard ΛCDM scenario. To quantify this statement, we focus on an extension of ΛCDM with DM-neutrino scattering, which leaves a distinctive imprint on the angular and matter power spectra. After finding that future CMB experiments (such as COrE+) will not significantly improve the constraints set by the Planck satellite, we show that the next generation of galaxy clustering surveys (such as DESI) could play a leading role in constraining alternative cosmologies and even have the potential to make a discovery. Typically we find that DESI would be an order of magnitude more sensitive to DM interactions than Planck, thus probing effects that until now have only been accessible via N-body simulations

    Awake craniotomy versus craniotomy under general anesthesia for the surgical treatment of insular glioma: choices and outcomes

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    Objective: To investigate differences in outcomes in patients who underwent surgery for insular glioma using an awake craniotomy (AC) vs. a craniotomy under general anesthesia (GA). Methods: Data from patients treated at our hospital between 2005 and 2015 were analyzed retrospectively. The preoperative, intraoperative, postoperative, and longer term follow-up characteristics and outcomes of patients who underwent surgery for primary insular glioma using either an AC or GA were compared. Results: Of the 52 identified patients, 24 had surgery using an AC and 28 had surgery under GA. The extent of resection was similar for the two anesthesia techniques: the median extent of resection was 61.4% (IQR: 37.8–74.3%) in the WHO grade <4 AC group vs. 50.5% (IQR: 35.0–71.2%) in the grade <4 GA group and 73.4

    Hyperlactatemia After Intracranial Tumor Surgery Does Not Affect 6-Month Survival: A Retrospective Case Series

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    BACKGROUND: Patients undergoing neurosurgery frequently exhibit hyperlactatemia. The aim of this study was to identify factors associated with hyperlactatemia and assess how hyperlactatemia impacts survival and hospital length of stay after intracranial tumor surgery. MATERIALS AND METHODS: This retrospective cohort study included 496 adult patients that underwent surgery between January 1, 2014 and December 31, 2015. We evaluated patient characteristics, surgery characteristics, pH, lactate, and blood glucose from blood samples collected on admission to the high-dependency unit and the morning after surgery, and 6-month outcome data. RESULTS: Hyperlactatemia (>2.0 mmol/L) occurred in >50% of patients, but only 7.7% had acidosis. Postoperative hyperlactatemia was not correlated with 6-month survival (P=0.987), but was correlated with (median [interquartile range]) longer hospital stays (6 [4 to 8.5] d vs. 5 [4 to 8] d; P=0.006), longer surgery duration (4:53 [4:01 to 6:18

    Maternal Glucose Concentrations in Early Pregnancy and Cardiometabolic Risk Factors in Childhood

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    Objective: This study aimed to examine the associations of maternal early-pregnancy glucose and insulin concentrations with offspring cardiometabolic risk factors and fat distribution. Methods: In a population-based prospective cohort study among 3,737 mothers and their children, random maternal glucose and insulin concentrations were measured at a median gestational age of 13.2 (95% range 10.5-17.1) weeks. Childhood fat, blood pressure, and blood concentrations of lipids, glucose, and insulin at the age of 10 years were measured. Results: Higher maternal early-pregnancy glucose and insulin concentrations were associated with a higher risk of childhood overweight, and higher maternal early-pregnancy insulin concentrations were associated with an increased childhood risk of clustering of cardiometabolic risk factors (all P < 0.05). These associations were explained by maternal prepregnancy BMI. Independent of maternal prepregnancy BMI, one SD score (SDS) higher maternal early-pregnancy glucose and insulin concentrations were associated with higher childhood glucose (0.08 SDS, 95% CI: 0.04-0.11) and insulin concentrations (0.07 SDS, 95% CI: 0.03-0.10), but not with childhood blood pressure, lipids, and fat measures. Conclusions: These results suggest that maternal early-pregnancy random glucose and insulin concentrations are associated with childhood glucose a

    Scaling in Numerical Simulations of Domain Walls

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    We study the evolution of domain wall networks appearing after phase transitions in the early Universe. They exhibit interesting dynamical scaling behaviour which is not yet well understood, and are also simple models for the more phenomenologically acceptable string networks. We have run numerical simulations in two- and three-dimensional lattices of sizes up to 4096^3. The theoretically predicted scaling solution for the wall area density A ~ 1/t is supported by the simulation results, while no evidence of a logarithmic correction reported in previous studies could be found. The energy loss mechanism appears to be direct radiation, rather than the formation and collapse of closed loops or spheres. We discuss the implications for the evolution of string networks.Comment: 7pp RevTeX, 9 eps files (including six 220kB ones
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