Carbon dioxide storage in the Captain Sandstone aquifer: determination of in situ stresses and fault-stability analysis

The Lower Cretaceous Captain Sandstone Member of the Inner Moray Firth has significant potential for the injection and storage of anthropogenic CO2 in saline aquifer parts of the formation. Pre-existing faults constitute a potential risk to storage security owing to the elevated pore pressures likely to result from large-scale fluid injection. Determination of the regional in situ stresses permits mapping of the stress tensor affecting these faults. Either normal or strike-slip faulting conditions are suggested to be prevalent, with the maximum horizontal stress orientated 33°–213°. Slip-tendency analysis indicates that some fault segments are close to being critically stressed under strike-slip stress conditions, with small pore-pressure perturbations of approximately 1.5 MPa potentially causing reactivation of those faults. Greater pore-pressure increases of approximately 5 MPa would be required to reactivate optimally orientated faults under normal faulting or transitional normal/strike-slip faulting conditions at average reservoir depths. The results provide a useful indication of the fault geometries most susceptible to reactivation under current stress conditions. To account for uncertainty in principal stress magnitudes, high differential stresses have been assumed, providing conservative fault-stability estimates. Detailed geological models and data pertaining to pore pressure, rock mechanics and stress will be required to more accurately investigate fault stability. Large-scale deployment of CO2 storage as a strategy for reducing greenhouse gas emissions will rely on the integrity of sealing strata overlying the storage reservoirs to ensure that the captured CO2 is permanently isolated from the atmosphere (IPCC 2005; Chadwick et al. 2009a; Holloway 2009). The existence of pre-existing fault systems of varying dimensions is a common feature throughout the subsurface, and the efficacy of seals may potentially be compromised by any enhanced transmissibility associated with fault zones. Within the Moray Firth, the Lower Cretaceous Captain Sandstone Member of the Wick Sandstone Formation has been proposed as a suitable storage reservoir candidate (SCCS 2011; Shell 2011a; Akhurst et al. 2015). Storage potential exists within depleting hydrocarbon fields (Marshall et al. 2016), while significant additional capacity is available in the surrounding saline aquifer volume. Regional top seals include the Cretaceous Rodby, Carrack and Valhall formations. Simulation studies of CO2 injection identified the storage capacity of the Captain Sandstone to be between 358 and 2495 Mt (Jin et al. 2012). As the injection of CO2 is reliant on the displacement of existing pore fluids, large-scale injection results in increased pore-fluid pressure, the effects of which will be felt across large areas in well-connected aquifer systems (Chadwick et al. 2009b; Jin et al. 2012; Noy et al. 2012). It is well documented that some faults are transmissible to fluid flow, while others act as effective capillary seals (Caine et al. 1996; Aydin 2000; Faulkner et al. 2010). Whether cross-fault flow occurs depends on the juxtaposition of lithologies in the footwall and hanging-wall blocks, as well as the composition of the fault zone and any differential pressure across the fault. In addition, reactivation of previously stable faults caused by increasing pressure, and therefore a reduction in the effective stress, could allow faults to become transmissive to buoyant fluids, such as supercritical CO2, due to the opening of flow pathways during failure (Streit & Hillis 2004). It is this aspect of fault stability that forms the focus of this study, with respect to the Captain Sandstone of the Inner Moray Firth, and utilizing an adaptation of the geological model presented by Jin et al. (2012). Analysis of the geomechanical stability of faults offsetting the Captain Sandstone requires the contemporary stress field affecting the basin to be characterized, in order to resolve the shear and normal stresses acting on mapped faults and to determine which faults, or segments of faults, are most susceptible to becoming reactivated if pore-fluid pressures in the basin are increased as a result of CO2 injection. In order to do so, detailed knowledge of the pore-pressure conditions at depth, the magnitude and orientations of the principal stresses, and the properties of the faults is required

Reconstructing Supersymmetry at ILC/LHC

Coherent analyses of experimental results from LHC and ILC will allow us to draw a comprehensive and precise picture of the supersymmetric particle sector. Based on this platform the fundamental supersymmetric theory can be reconstructed at the high scale which is potentially close to the Planck scale. This procedure will be reviewed for three characteristic examples: minimal supergravity as the paradigm; a left-right symmetric extension incorporating intermediate mass scales; and a specific realization of string effective theories.Comment: published in Proceedings of the Ustron Conference 2005; technical LaTeX problem correcte

Continuous N-alkylation reactions of amino alcohols using γ-Al2O3 and supercritical CO2: unexpected formation of cyclic ureas and urethanes by reaction with CO2

The use of γ-Al2O3 as a heterogeneous catalyst in scCO2, has be successfully applied to the amination of alcohols for the synthesis of N-alkylated heterocycles. The optimal reaction conditions (temperature and substrate flow rate) were determined using an automated self-optimising reactor, resulting in moderate to high yields of the target products. Carrying out the reaction in scCO2 was shown to be beneficial, as higher yields were obtained in the presence of CO2 than in its absence. A surprising discovery is that, in addition to cyclic amines, cyclic ureas and urethanes could be synthesised by incorporation of CO2 from the supercritical solvent into the product

SUSY Parameter Analysis at TeV and Planck Scales

Coherent analyses at future LHC and LC experiments can be used to explore the breaking mechanism of supersymmetry and to reconstruct the fundamental theory at high energies, in particular at the grand unification scale. This will be exemplified for minimal supergravity.Comment: 7 pages, 3 figures, uses espcrc2.sty (included), Proceedings, Loops and Legs 2004, Zinnowitz on Usedo

The Influence of Match-Day Napping in Elite Female Netball Athletes

Purpose: To assess the effect of match-day napping and duration of naps on perceptual and performance indices in elite female netball players over two consecutive netball seasons. Methods: Fourteen elite female netball athletes (mean ± SD; age = 23 ± 6 yr) participated in an observational study over 26 competition matches. On each match day, athletes provided information on their napping habits, perceived energy levels, and then performed 3 countermovement jumps (CMJ) 3h30 prior to the start of the match. One hour following the match, subjective player performance ratings from the players and two members of the coaching staff were obtained. Naps were characterized into 3 conditions for analysis; No Nap (NN), <20 min Nap (SHORT), and ≥20 min Nap (LONG). Results: A significant difference in peak jump velocity was observed between the SHORT and the NN condition in favor of the shorter nap (3.23 ± 0.26 and 3.07 ± 0.36 m.s-1, respectively, d = 0.34, p < 0.05). A moderate, significant difference (d = 0.85; p < 0.05) was observed for the coach rating of performance (out of 10) between the SHORT and the NN condition (7.2 ± 0.8 and 6.4 ± 0.9, respectively) in favor of SHORT. Conclusion: The findings from the study would suggest that a short nap (<20 min) on the day of competition can enhance jump velocity and improve subjective performance in elite netball players, as assessed by coaching staff

Piezoresponse force microscopy investigations of Aurivillius phase thin films

The sol-gel synthesis and characterization of n≥3n≥3 Aurivillius phase thin filmsdeposited on Pt/Ti/SiO2–SiPt/Ti/SiO2–Si substrates is described. The number of perovskite layers, nn, was increased by inserting BiFeO3BiFeO3 into three layered Aurivillius phase Bi4Ti3O12Bi4Ti3O12 to form compounds such as Bi5FeTi3O15Bi5FeTi3O15 (n=4)(n=4). 30% of the Fe3+Fe3+ ions in Bi5FeTi3O15Bi5FeTi3O15 were substituted with Mn3+Mn3+ ions to form the structureBi5Ti3Fe0.7Mn0.3O15Bi5Ti3Fe0.7Mn0.3O15. The electromechanical responses of the materials were investigated using piezoresponse force microscopy and the results are discussed in relation to the crystallinity of the films as measured by x-ray diffraction

Reconstruction of Fundamental SUSY Parameters

We summarize methods and expected accuracies in determining the basic low-energy SUSY parameters from experiments at future e$^+$e$^-$ linear colliders in the TeV energy range, combined with results from LHC. In a second step we demonstrate how, based on this set of parameters, the fundamental supersymmetric theory can be reconstructed at high scales near the grand unification or Planck scale. These analyses have been carried out for minimal supergravity [confronted with GMSB for comparison], and for a string effective theory.Comment: 8 pages, latex, 7 figures, expanded version of contributions to the proceedings of ICHEP.2002 (Amstersdam) and LCWS.2002 (Jeju Island

Room temperature electromechanical and magnetic investigations of ferroelectric Aurivillius phase Bi5Ti3(FexMn1−x)O15 (x = 1 and 0.7) chemical solution deposited thin films

Aurivillius phase thin films of Bi5Ti3(FexMn1−x)O15 with x = 1 (Bi5Ti3FeO15) and 0.7 (Bi5Ti3Fe0.7Mn0.3O15) on SiO2-Si(100) and Pt/Ti/SiO2-Si substrates were fabricated by chemical solution deposition. The method was optimized in order to suppress formation of pyrochlore phase Bi2Ti2O7 and improve crystallinity. The structuralproperties of the films were examined by x-ray diffraction, scanning electron microscopy, and atomic force microscopy. Optimum crystallinity and pyrochlore phase suppression was achieved by the addition of 15 to 25 mol. % excess bismuth to the sols. Based on this study, 17.5 mol. % excess bismuth was used in the preparation of Bi2Ti2O7-free films of Bi5Ti3FeO15 on SrTiO3(100) and NdGaO3(001) substrates, confirming the suppression of pyrochlore phase using this excess of bismuth. Thirty percent of the Fe3+ ions in Bi5Ti3FeO15 was substituted with Mn3+ ions to form Bi2Ti2O7-free thin films of Bi5Ti3Fe0.7Mn0.3O15 on Pt/Ti/SiO2-Si, SiO2-Si(100), SrTiO3(100), and NdGaO3(001) substrates. Bi5Ti3FeO15 and Bi5Ti3Fe0.7Mn0.3O15thin films on Pt/Ti/SiO2-Si and SiO2-Si(100) substrates were achieved with a higher degree of a-axis orientation compared with the films on SrTiO3(100) and NdGaO3(001) substrates. Room temperature electromechanical and magnetic properties of the thin films were investigated in order to assess the potential of these materials for piezoelectric,ferroelectric, and multiferroic applications. Vertical piezoresponse force microscopy measurements of the films demonstrate that Bi5Ti3FeO15 and Bi5Ti3Fe0.7Mn0.3O15thin films are piezoelectric at room temperature. Room temperature switching spectroscopy-piezoresponse force microscopy measurements in the presence and absence of an applied bias demonstrate local ferroelectric switching behaviour (180°) in the films. Superconducting quantum interference device magnetometry measurements do not show any room temperature ferromagnetic hysteresis down to an upper detection limit of 2.53 × 10−3 emu; and it is concluded, therefore, that such films are not mutiferroic at room temperature. Piezoresponse force microscopy lithography images of Bi5Ti3Fe0.7Mn0.3O15thin films are presented

Testing a model of antecedents and consequences of defensive pessimism and self-handicapping in school physical education

There has been very limited research on the use of self-worth protection strategies in the achievement context of school physical education (PE). Thus, this study aimed to examine some antecedents and consequences of defensive pessimism and self-handicapping. The sample comprised 534 (females n = 275; males n = 259) British pupils recruited from two schools who responded to established questionnaires. Results of structural equation modelling analysis indicated that self-handicapping and defensive pessimism were positively predicted by fear of failure and negatively predicted by competence valuation. In addition, defensive pessimism was negatively predicted by physical self-concept. In turn, defensive pessimism negatively predicted enjoyment in PE and intentions to participate in future optional PE programs. Self-handicapping did not predict enjoyment or intentions. Results from multi-sample structural equation modelling showed the specified model to be largely invariant across males and females. The findings indicate that although both strategies aim to protect one’s self-worth, some of their antecedents and consequences in PE may differ