A 3D conductivity model of the Isle of Wight, UK, from airborne EM data

This study reports the first airborne electromagnetic (AEM) survey in southern England. An airborne geophysical survey incorporating magnetic, radiometric and electromagnetic observations was carried out in 2007 over a 36 x 22 km area incorporating the Isle of Wight. The island is of significant geological interest due to the nature of the reactivated Variscan thrust faulting causing near vertical bedding along a central monocline. Of primary interest to this study was a first chance to deploy AEM over a significant chalk deposit and to assess the accuracy and resolution of the final 3D models in regions of significantly dipping, but well mapped, sedimentary beds. The results of multi-layer inversion are displayed across a 3D conductivity volume. The conductive Gault clay/mudstone is highly resolved against the more resistive Upper Greensand and Chalk and provides a detailed mapping of the concealed geological structure

Extension of forward modeling phase-screen code to for AVO analysis in isotropic and anisotropic media

The computationally efficient phase-screen forward modeling technique is extended to allow investigation of non-normal ray paths. The code is developed to accommodate all diffracted and converted phases up to critical angle, building on a geometrical construction method. The new approach relies upon pre-scanning the model space to assess the complexity of each screen. The propagating wavefields are then divided as a function of horizontal wavenumber, and each subset is transformed to the spatial domain separately, carrying with it angular information. This allows both accurate 3-D phase corrections and Zoeppritz reflection and transmission coefficients to be applied. The phase-screen code is further developed to handle simple anisotropic media. During phasescreen modeling, propagation is undertaken in the wavenumber domain where exact expressions for anisotropic phase velocities are available. Travel-times and amplitude effects from a range of anisotropic shales are computed and compared with previous literature

The construction of a normative instrument for the measurement of moral reasoning

The main aim of this study was to construct a normative instrument for the measurement of different levels of moral reasoning. The sample comprised 426 undergraduate students in Industrial Psychology and Personnel Management from two Afrikaans speaking universities. A questionnaire was developed to measure different levels of moral reasoning on a normative scale. A factor analysis on 90 items yielded two factors. These factors were interpreted as principled moral reasoning and prescriptive moral reasoning. The two scales were subjected to an item analysis and yielded reliability coefficients of 0,936 and 0,937. The implications of these findings are discussed

The impact of parent-created motivational climate on adolescent athletes' perceptions of physical self-concept

This is a preliminary version of this article. The official published version can be obtained from the link below.Grounded in expectancy-value model (Eccles, 1993) and achievement goal theory (Nicholls, 1989), this study examined the perceived parental climate and its impact on athletes' perceptions of competence and ability. Hierarchical regression analyses with a sample of 237 British adolescent athletes revealed that mothers and fathers' task- and ego-involving climate predicted their son's physical self-concept; the father in particular is the strongest influence in shaping a son's physical self-concept positively and negatively. It was also found that the self-concept of the young adolescent athlete is more strongly affected by the perceived parental-created motivational climate (both task and ego) than the older adolescent athlete's self-concept. These findings support the expectancy-value model assumptions related to the role of parents as important socializing agents, the existence of gender-stereotyping, and the heavy reliance younger children place on parents' feedback

CO2 saturation and thickness predictions in the Tubåen Fm., Snøhvit field, from analytical solution and time-lapse seismic data

CO2 migration in a saline aquifer is governed by viscous, capillary and gravitational fluid forces at an early stage of injection, where the dominant flow regime is site specific and controls the fluid migration in the pore space. This study combines the CO2 saturation inverted from time-lapse seismic methods with an analytical expression to define the CO2 flow regime, saturation distribution and layer thickness in the Tubåen Fm. following CO2 injection. Quantitative estimates of the CO2 saturation from time-lapse seismic amplitude versus offset (AVO) and spectral decomposition are compared to a viscous dominated analytical expression of CO2 injection into a saline aquifer. The spatial extent of the CO2 plume obtained from time-lapse spectral decomposition and inverted from time-lapse AVO analysis display good agreement with the analytical expression. The CO2 is limited to an area close to the injection well, with an elongated shape in the channel direction. Comparison between the time-lapse seismic and analytical expression shows that the fluid flow is dominated by viscous forces. CO2 saturation within the plume is constant and close to the residual brine saturation. The influence of gravity is ignorable on the reservoir CO2 flow. CO2 fills the entire sandstone unit up to approximately 50 m away from the injection before the CO2 layer thickness is reduced to a thin wedge that propagates below the overlying shale unit. Reduction in CO2 saturation away from the injection well is a reduction in effective CO2 saturation relative to the thickness of the horizon. The maximum radius of the CO2 layer from the analytic expression is 750 m, of which 400 m is above the time-lapse noise level. Time-lapse seismic analysis reveals the CO2 layer radius is 405 m in the direction of the local fluvial channel and 273 m in the perpendicular direction

An inverse method for estimating thickness and volume with time of a thin CO2-filled layer at the Sleipner Field, North Sea

Migration of CO 2 through storage reservoirs can be monitored using time lapse seismic reflection surveys. At the Sleipner Field, injected CO 2 is distributed throughout nine layers within the reservoir. These layers are too thin to be seismically resolvable by direct measurement of the separation between reflections from the top and bottom of each layer. Here we develop and apply an inverse method for measuring thick ness changes of the shallowest layer. Our approach combines differences in traveltime down to a specific reflection together with amplitude measurements to determine layer thicknesses from time lapse surveys. A series of synthetic forward models were used to test the robustness of our inverse approach and to quantify uncertainties. In the absence of ambient noise, this approach can unambiguously resolve layer thickness. If a realistic ambient noise distribution is included, layer thicknesses of 1–6 m are accurately retrieved with an uncertainty of ±0.5 m. We used this approach to generate a thickness map of the shallowest layer. The fidelity of this result was tested using measurements of layer thickness determined from the 2010 broadband seismic survey. The calculated volume of CO 2 within the shallowest layer increases at a rate that is quadratic in time, despite an approximately constant injection rate into the base of the reser voir. This result is consistent with a diminished growth rate of the areal extent of underlying layers. Finally, the relationship between caprock topography and layer thickness is explored and potential migration pathways that charge this layer are identified

Role of the dental hospital-based paediatric liaison nurse in safeguarding children

Aim: Service evaluation of our dental hospital paediatric liaison nursing (DH-PLN) service which provides an additional route for information sharing about safeguarding concerns via an agreed pathway for two-way communication with public health nurses. Method: Retrospective analysis of clinical records of all children referred by DH teams to PLN in the three months October-December 2016. Results: One hundred and four children were referred; mean age was 6.2 years, 89.4% from Index of Multiple Deprivation (IMD) quintiles 4 and 5, and 70.2% were attending for dental general anaesthesia. The most common referral reason was dental neglect in 66.3%, followed by missed appointments in 50.0%. The PLN checked child health databases and shared information with health visitors and school nurses (46.2% and 53.8% respectively). Feedback retrieved included known child maltreatment risk factors in 7.7%. This prompted additional child protection referrals to children's social services for seven children (6.7%). Dental outcomes six months later were: treatment complete in 50.0%, treatment ongoing 28.8%, discharged to original referrer with treatment incomplete in 21.1%. Conclusion: This DH-PLN service promotes integrated multidisciplinary working, helping overcome barriers to dentistry's involvement in safeguarding. It facilitates more accurate assessments of risk of harm to children receiving dental care and prompts additional child protection referrals to social services

The spin and charge gaps of the half-filled N-leg Kondo ladders

In this work, we study N-leg Kondo ladders at half-filling through the density matrix renormalization group. We found non-zero spin and charge gaps for any finite number of legs and Kondo coupling $J>0$. We also show evidence of the existence of a quantum critical point in the two dimensional Kondo lattice model, in agreement with previous works. Based on the binding energy of two holes, we did not find evidence of superconductivity in the 2D Kondo lattice model close to half-filling.Comment: 4 pages, 1 table, 3 fig

Was atmospheric CO2 capped at 1000ppm over the past 300 million years?

AbstractAtmospheric carbon dioxide concentration has shifted dynamically over the Phanerozoic according to mass balance models and the majority of proxy estimates. A new paleo-CO2 proxy method underpinned by mechanistic understanding of plant stomatal, isotopic and photosynthetic responses to CO2 has provocatively claimed that maximum paleoatmospheric CO2 was capped at 1000ppm for the majority of the past 300 million years. Here we evaluate the robustness of the new paleo-proxy CO2 model by testing its sensitivity to initial parameterization and to scaling factors employed to estimate paleophysiological function from anatomical and morphological traits. A series of sensitivity analyses find that the model is robust to modification in some of the constants employed, such as CO2 compensation point and mesophyll conductance, resulting in variability in paleo-CO2 estimates which are already accounted for in the error propagation of the model. We demonstrate high sensitivity in the model to key input parameters such as initial fossil plant assimilation rate, termed A0 and scaling factors used to estimate stomatal conductance from measurements of fossil stomata. Incorrect parameterization of A0 has resulted in under estimation of pCO2 by as much as 600ppm. Despite these uncertainties, our analysis highlights that the new mechanistic paleo-CO2 proxy of Franks et al. (2014) has significant potential to derive robust and more accurate CO2 estimates from fossil plant stomata, as long as parameterization of A0 is strongly justified with species appropriate morphological and anatomical data. We highlight methods that can be used to improve current estimates of fossil plant assimilation rates, reduce uncertainty associated with implementation of the Franks et al. (2014) model and importantly add to understanding of patterns of plant productivity over the Phanerozoic, for which there currently is no consensus

Computational Stylometry: An Interdisciplinary Project

This project was an analysis of a writers word usage and writing tendencies which, allows a person to recognize a piece of work with out knowing who wrote it and make a reasonable guess about whose work it is