A MULTIDISCIPLINARY ASSESSMENT OF HYALOCLASTITE DEPOSITS IN PETROLEUM SYSTEMS USING FIELD STUDIES, DRILL CORE, BOREHOLE IMAGE AND WIRE-LINE LOG DATASETS

This thesis aims to document hyaloclastite deposits in different depositional environments from field outcrops in Iceland to characterise lithofacies heterogeneity enabling comparison to subsurface datasets. Field hyaloclastite datasets from Stóri-Núpur (subaerial-marine transition) and Hjörleifshöfði (an emergent Surtseyan volcano) are used to support the interpretation of hyaloclastite and associated volcanic deposits in core, borehole image logs and wire-line log datasets from Hawaii (Hawaiian Scientific Drilling Project II – HSDP II borehole) and the Faroe-Shetland Basin (LOPRA1/1A well and the Rosebank field). This study provides additional constraints on lava delta formation in predominantly basaltic systems where hyaloclastite depositional profiles reflect localised extrusion pathways and syn-sediment reworking which control 3D lithofacies architecture. Furthermore this thesis documents the evolution of Hjörleifshöfði using field mapping and major/trace element geochemistry. Hjörleifshöfði can split into five phases of deposition charting the submarine to emergent building of the volcano, unique as it also records a phase of silicic volcanism (Sólheimar Ignimbrite) which dates late stage volcanism to no earlier than 12,383 C14 years BP. Petrophysical and petrographic observations suggest hyaloclastite deposits are unique in terms of their velocity/density and P and S wave relationships due to palagonite formation, basalt clast support, phenocryst and zeolite component amongst others which impacts on depth conversion and the calculation of reflection coefficients. Wire-line log response gamma-ray (GR), resistivity (RES), P-wave sonic velocity (Vp) is also closely linked to the dominant interstitial secondary minerals and phenocryst components of sideromelane glass. Borehole image log analysis of mixed volcanic and volcaniclastic rocks allows the accurate characterisation of distinct internal lava flow features, contact relationships and joint networks enabling better characterisation of volcanic sequences in the subsurface via careful comparison with field examples. Field, core and wire-line log data is combined to form a multidisciplinary assessment of hyaloclastite deposits in the subsurface suggesting that the complexity and scaling issues in hyaloclastite rocks is generally overlooked which may impact on future petroleum exploration in volcanic basins

Performance and degradation of solid oxide cells for steam electrolysis

In this thesis testing of solid oxide cells in fuel cell and electrolysis operation have been performed. Attempts to fabricate fuel cells are described, equipment for testing solid oxide electrolysis cells has been constructed and the development process for this described. Cells of a number of different types have been tested in which initial work was performed using microtubular cells. Work on the fabrication of planar solid oxide cells is described, anode supports were prepared by pellet pressing however the application of a suitably dense electrolyte was unsuccessful which resulted in a poor cell OCV. The initial degradation of commercial solid oxide cells has been investigated. During cyclic testing at low current density the cells were found to degrade at twice the rate in electrolysis operation compared to fuel cell operation. This leads to the conclusion that the degradation observed in electrolysis is reversible and that there is a disconnect between the electrolysis and fuel cell degradation processes. During testing at different current densities the cells were found to undergo severe degradation when operated with very low water content supplied to the cells. The degradation was 512 mV kh$^{−1}$ at 2.5 vol% H2O and reduced to 45mV kh$^{−1}$ at 50 vol% H2O. Over the timescales investigated in this work and due to the reversible nature of the electrolysis degradation identifying a degradation mechanism was very difficult

Phosphatidylserine is a critical modulator for Akt activation

Association of Akt with phosphatidylserine enhances binding to PIP3, inducing conformational changes in Akt that promote its phosphorylation-mediated activation

Inclusive and differential cross-section measurements of t\bartZ production in pp collisions at √s=13 TeV with the ATLAS detector, including EFT and spin-correlation interpretations

Measurements of both the inclusive and differential production cross sections of a top-quark-top-antiquark pair in association with a Z boson (tt¯Z) are presented. Final states with two, three or four isolated leptons (electrons or muons) are targeted. The measurements use the data recorded by the ATLAS detector in pp collisions at s√=13 TeV at the Large Hadron Collider during the years 2015-2018, corresponding to an integrated luminosity of 140 fb−1. The inclusive cross section is measured to be σtt¯Z=0.86±0.04 (stat.)±0.04 (syst.) pb and found to be in agreement with the most advanced Standard Model predictions. The differential measurements are presented as a function of a number of observables that probe the kinematics of the tt¯Z system. Both the absolute and normalised differential cross-section measurements are performed at particle level and parton level for specific fiducial volumes, and are compared with NLO+NNLL theoretical predictions. The results are interpreted in the framework of Standard Model effective field theory and used to set limits on a large number of dimension-6 operators involving the top quark. The first measurement of spin correlations in tt¯Z events is presented: the results are in agreement with the Standard Model expectations, and the null hypothesis of no spin correlations is disfavoured with a significance of 1.8 standard deviations

Observation of quantum entanglement in top-quark pairs using the ATLAS detector

We report the highest-energy observation of entanglement, in top−antitop quark events produced at the Large Hadron Collider, using a proton−proton collision data set with a center-of-mass energy of s√=13 TeV and an integrated luminosity of 140 fb−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top−antitop quark production threshold, where the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from limitations of the Monte Carlo event generators and the parton shower model in modelling top-quark pair production. The entanglement marker is measured to be D=−0.547±0.002 (stat.)±0.021 (syst.) for 340<mtt¯<380 GeV. The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes both the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement to date

PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

A detailed evaluation of the effects of bulk residual stress on fatigue in aluminum

The fully effective utilization of large aluminum forgings in aerospace structures has been hampered in the past by inadequate understanding of, and sometimes inaccurate representation of, bulk residual stresses and their impact on both design mechanical properties and structural performance. In recent years, significant advances in both computational and experimental methods have led to vastly improved characterization of residual stresses. As a result, new design approaches which require the extraction of residual stress effects from material property data and the formal inclusion of residual stresses in the design analysis, have been enabled. In particular, the impact of residual stresses on durability and damage tolerance can now be assessed, and more importantly, accounted for at the beginning of the design cycle. In an effort to support the development of this next-generation design capability, the AFRL sponsored Metals Affordability Initiative (MAI) consortium has conducted a detailed experimental and analytical study of fatigue crack initiation and fatigue crack growth in aluminum coupons with known, quench induced residual stresses. In this study, coupons were designed and manufactured such that simple 'design features,' such as holes and machined pockets, were installed in locations with varying levels of bulk residual stress. The residual stresses at the critical locations in the coupons were measured using multiple techniques and modeled using detailed finite element analysis. Fatigue crack initiation (FCI) and fatigue crack growth (FCG) tests were performed using both constant amplitude and spectrum loading and the results were compared against computed FCI and FCG lives. © (2014) Trans Tech Publications, Switzerland

A Detailed Evaluation of the Effects of Bulk Residual Stress on Fatigue in Aluminum

The fully effective utilization of large aluminum forgings in aerospace structures has been hampered in the past by inadequate understanding of, and sometimes inaccurate representation of, bulk residual stresses and their impact on both design mechanical properties and structural performance. In recent years, significant advances in both computational and experimental methods have led to vastly improved characterization of residual stresses. As a result, new design approaches which require the extraction of residual stress effects from material property data and the formal inclusion of residual stresses in the design analysis, have been enabled. In particular, the impact of residual stresses on durability and damage tolerance can now be assessed, and more importantly, accounted for at the beginning of the design cycle. In an effort to support the development of this next-generation design capability, the AFRL sponsored Metals Affordability Initiative (MAI) consortium has conducted a detailed experimental and analytical study of fatigue crack initiation and fatigue crack growth in aluminum coupons with known, quench induced residual stresses. In this study, coupons were designed and manufactured such that simple 'design features,' such as holes and machined pockets, were installed in locations with varying levels of bulk residual stress. The residual stresses at the critical locations in the coupons were measured using multiple techniques and modeled using detailed finite element analysis. Fatigue crack initiation (FCI) and fatigue crack growth (FCG) tests were performed using both constant amplitude and spectrum loading and the results were compared against computed FCI and FCG lives. © (2014) Trans Tech Publications, Switzerland

High-resolution structure of the pleckstrin homology domain of protein kinase B/Akt bound to phosphatidylinositol (345)-trisphosphate

AbstractThe products of PI 3-kinase activation, PtdIns(3,4,5)P3 and its immediate breakdown product PtdIns(3,4)P2, trigger physiological processes, by interacting with proteins possessing pleckstrin homology (PH) domains [1, 2]. One of the best characterized PtdIns(3,4,5)P3/PtdIns(3,4)P2 effector proteins is protein kinase B (PKB), also known as Akt [3–5]. PKB possesses a PH domain located at its N terminus, and this domain binds specifically to PtdIns(3,4,5)P3 and PtdIns(3,4)P2 with similar affinity [6, 7]. Following activation of PI 3-kinase, PKB is recruited to the plasma membrane by virtue of its interaction with PtdIns(3,4,5)P3/PtdIns(3,4)P2 [8–10]. PKB is then activated by the 3-phosphoinositide-dependent pro-tein kinase-1 (PDK1), which like PKB, possesses a PtdIns(3,4,5)P3/PtdIns(3,4)P2 binding PH domain [11, 12]. Here, we describe the high-resolution crystal structure of the isolated PH domain of PKBα in complex with the head group of PtdIns(3,4,5)P3. The head group has a significantly different orientation and location compared to other Ins(1,3,4,5)P4 binding PH domains. Mutagenesis of the basic residues that form ionic interactions with the D3 and D4 phosphate groups reduces or abolishes the ability of PKB to interact with PtdIns(3,4,5)P3 and PtdIns(3,4)P2. The D5 phosphate faces the solvent and forms no significant interactions with any residue on the PH domain, and this explains why PKB interacts with similar affinity with both PtdIns(3,4,5)P3 and PtdIns(3,4)P2