Exploring Experiences of Stigma in Parents of Children with Autism

Aims This study aimed to develop a theoretical model to understand how parents of children with autism manage and respond to stigma they may experience. Method Twelve parents of children with a diagnosis of autism, aged 10 and under, completed semi-structured interviews about their experiences of stigma and how they respond to stigmatising encounters. A constructivist grounded theory approach was taken to examine parents’ narratives and develop theoretical codes. Results A theoretical model is proposed to understand how parents of children with autism manage and respond to stigma. Two variables are highlighted in this model - parents’ responses were dependent on who the stigmatiser was and who was being stigmatised. Four core responses to stigma were identified: 'actively ignoring,' 'actively withdrawing,' 'avoiding' and 'challenging.' Parents’ narratives illustrated the context those responses would be used in. Conclusions Whilst the results show the on-going challenges that parents of children with autism face, they also illustrate the skills and resilience such parents have often developed to manage stigma

Capacity Limits in Visual Processing Revealed by Spatial Biases

Our early visual system extracts fine grained information about our rapidly changing world, yet in certain laboratory conditions, participants fail to report some items that are clearly presented within their field of vision. These failures are likely to occur because later stages of the visual system do not have capacity to process all of the information extracted at the retina. In this thesis, I investigate a particular failure of awareness that occurs when two target letters are briefly presented at the same time in different spatial locations. A clue to the cause of these failures may lie in the spatial pattern of errors that participants make. A recent theory suggests that the consistency in spatial errors across participants may reflect a functional strategy used by the brain to prioritise information at a key processing bottleneck. I investigate this claim, and conduct research to investigate other aspects of the limitation, such as the processing stage at which it occurs, and its implications for visual processing tasks such as reading

Normal state properties of high angle grain boundaries in (Y,Ca)Ba2Cu3O7-delta

By lithographically fabricating an optimised Wheatstone bridge geometry, we have been able to make accurate measurements of the resistance of grain boundaries in Y1-xCaxBa2Cu3O7-d between the superconducting transition temperature, Tc, and room temperature. Below Tc the normal state properties were assessed by applying sufficiently high currents. The behaviour of the grain boundary resistance versus temperature and of the conductance versus voltage are discussed in the framework charge transport through a tunnel barrier. The influence of misorientation angle, oxygen content, and calcium doping on the normal state properties is related to changes of the height and shape of the grain boundary potential barrier.Comment: 17 pages, 1 table, 5 figures, submitted to PR

Integrated Numerical Modelling System for Extreme Wave Events at the Wave Hub Site

This paper examines an extreme wave event which occurred during a storm at the Wave Hub site in 2012. The extreme wave of 9.57 m height was identified from a time series of the heave data collected by an Oceanor Seawatch Mini II Buoy deployed at the site. An energy density spectrum was derived from this time series and then used to drive a physical model, which represents the extreme wave at 1:20 scale in Plymouth University’s new COAST Lab. The NewWave technique was used to define the input to the physical model. The experiment is reproduced in a numerical wave tank using the fully nonlinear CFD library OpenFOAM® and the wave generation toolbox waves2Foam. Results are evaluated, and issues regarding the predictions of a numerical model that is driven by the NewWave input signal are discussed. This study sets the basis for further research in coupling field data, physical modelling and numerical modelling in a more efficient and balanced way. This will lead to the new approach of composite modelling that will be implemented in future work

Active chainmail fabrics for soft robotic applications

This paper introduces a novel type of smart textile with electronically responsive flexibility. The chainmail inspired fabric is modelled parametrically and simulated via a rigid body physics framework with an embedded model of temperature controlled actuation. Our model assumes that individual fabric linkages are rigid and deform only through their own actuation, thereby decoupling flexibility from stiffness. A physical prototype of the active fabric is constructed and it is shown that flexibility can be significantly controlled through actuator strains of ≤10%. Applications of these materials to soft-robotics such as dynamically reconfigurable orthoses and splints are discussed

Mental health and behavioural difficulties in adopted children: A systematic review of post-adoption risk and protective factors

Previous research suggests that adopted children are at a greater risk of experiencing psychological and behavioural difficulties or accessing mental health services than non-adopted peers and that post-adoption variables are significant risk and protective factors producing this situation. This review seeks to summarise the post-adoption variables associated with adopted children’s mental health or behavioural difficulties to inform future research and shape interventions. A search for publications that assess associated risk and protective factors using Web of Science, Psychinfo, Medline and Sociological Abstracts identified 52 studies that met rigorous methodological criteria. Children’s and adolescents’ mental health and behavioural outcomes were associated with parent, parent–child and wider family factors and by contextual variables. The findings highlight the importance of focusing on the multitude of systemic factors surrounding a child following adoption. Clinical implications and direction for future research are discussed

The Properties of Grain Boundaries in YBa2Cu3O7-d

Grain boundaries form the basis of an important Josephson junction technology in the cuprates and also limit the superconducting critical currents attainable in practical, polycrystalline materials. An improved understanding of these defects is therefore important for applications. The status of the current understanding of cuprate grain boundaries is summarised and experimental investigations are presented, focusing on the less well understood high angle boundaries. Measurements of the capacitance of grain boundaries in the overdoped superconductor Y1-xCaxBa2Cu3O7-8, were performed as a function of the calcium content, using the Josephson coupling across the boundaries. Particular care was taken to eliminate the e ects of heating and stray capacitance due to the substrate. The e ect of thermal noise was also assessed. These measurements provide important information about the area and the width of the grain boundaries, that highlights their inhomogeneous nature. A new technique was applied to measure the normal state properties of YBa2Cu3O7-8 grain boundaries above the critical temperature. Since the resistance of the adjacent material at high temperatures is comparable to, or greater than that of the grain boundary, a compensating Wheatstone bridge structure was used. The errors involved in this technique are carefully assessed and quanti ed. The normal state resistance of a number of di erent grain boundary orientations was measured from room temperature to the critical temperature. Detailed characterisation of the grain boundaries, including measurements of the critical current and the current voltage characteristics at low temperatures, was performed. The results obtained are used to assess the validity of the various theories for the grain boundary electrical structure. A tunneling model that accounts for the band structure of the material is developed and applied to potential barriers consistent with a band bending model. This theory is shown to provide a convincing account of the experimental results presented in this thesis.EPSR

Survivability of Wave Energy Converter and Mooring Coupled System using CFD

Full version unavailable due to 3rd party copyright restrictions.This thesis discusses the development of a Numerical Wave Tank (NWT) capable of describing the coupled behaviour of Wave Energy Converters (WECs) and their moorings under extreme wave loading. The NWT utilises the open-source Computational Fluid Dynamics (CFD) software OpenFOAM(R) to solve the fully nonlinear, incompressible, Reynolds-Averaged Navier-Stokes (RANS) equations for air and water using the Finite Volume Method (FVM) and a Volume of Fluid (VOF) treatment of the interface. A method for numerically generating extreme waves is devised, based on the dispersively-focused NewWave theory and using the additional toolbox waves2Foam. A parametric study of the required mesh resolution shows that steeper waves require finer grids for mesh independence. Surface elevation results for wave-only cases closely match those from experiments, although an improved definition of the flow properties is required to generate very steep focused waves. Predictions of extreme wave run-up and pressure on the front of a fixed truncated cylinder compare well with physical measurements; the numerical solution successfully predicts the secondary loading cycle associated with the nonlinear ringing effect and shows a nonlinear relationship between incident crest height and horizontal load. With near perfect agreement during an extreme wave event, the reproduction of the six degree of freedom (6DOF) motion and load in the linearly-elastic mooring of a hemispherical-bottomed buoy significantly improves on similar studies from the literature. Uniquely, this study compares simulations of two existing WEC designs with scale-model tank tests. For the Wavestar machine, a point-absorber constrained to pitch motion only, results show good agreement with physical measurements of pressure, force and float motion in regular waves, although the solution in the wake region requires improvement. Adding bespoke functionality, a point-absorber designed by Seabased AB, consisting of a moored float and Power Take-Off (PTO) with limited stroke length, translator and endstop, is modelled in large regular waves. This represents a level of complexity not previously attempted in CFD and the 6DOF float motion and load in the mooring compare well with experiments. In conclusion, the computational tool developed here is capable of reliably predicting the behaviour of WEC systems during extreme wave events and, with some additional parameterisation, could be used to assess the survivability of WEC systems at full-scale before going to the expense of deployment at sea.Engineering and Physical Sciences Research Council (EPSRC) via SuperGen UK Centre for Marine Energy Research (UKCMER