The compounding of short fibre reinforced thermoplastic composites

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.It is generally accepted that the mechanical properties of short fibre reinforced thermoplastics do not correspond with the high mechanical properties of fibres used to reinforce them. A study is made into the methods of compounding reinforcing fibres into thermoplastics to produce short fibre reinforced thermoplastics of enhanced properties. The initial method chosen for investigation is the twin screw extrusion compounding process. Variables such as fibre feeding arrangement and extrusion screw design are found to be factors influencing the properties of carbon and glass reinforced nylon 6,6. Use is made of computer programs to predict properties, assess compound quality and estimate fibre-matrix bond strength. Investigations indicate that the presence of reinforcing fibres with enhanced lengths does not result in the predicted property increases. The reasons for this shortfall are believed to lie in unfavourable fibre orientation in injection mouldings and the reduced strain to break of these materials. Short Kevlar reinforced thermoplastics are compounded and their mechanical properties assessed. The reasons for the poor mechanical properties for these materials are identified as a poor bond strength between fibre and matrix, the formation of points of weakness within the fibres by the compounding and moulding processes and the coiled arrangement of fibres present in injection mouldings. A method suitable for the routine assessment of fibre-matrix bond strength is used to examine combinations of fibre and thermoplastic matrix. A comparison is made of the values derived from this method with values calculated from stress-strain curves of injection mouldings. This allows an understanding of the nature of the fibre-matrix bond yielded by compounding and injection moulding steps. A description is given of a novel method designed to overcome the limitations of conventional compounding routes to produce long fibre reinforced injection moulding feedstock. Further work is necessary before this method is a feasible production technique

Systematic review of pain medicine content, teaching, and assessment in medical school curricula internationally

Introduction: Pain management is a major health care challenge in terms of the significant prevalence of pain and the negative consequences of poor management. Consequently, there have been international calls to improve pain medicine education for medical students. This systematic review examines the literature on pain medicine education at medical schools internationally, with a particular interest in studies that make reference to: a defined pain medicine curriculum, specific pain medicine learning objectives, dedicated pain education modules, core pain topics, medical specialties that teach pain medicine, elective study opportunities, hours allocated to teaching pain medicine during the curriculum, the status of pain medicine in the curriculum (compulsory or optional), as well as teaching, learning, and assessment methods. Methods: A systematic review was undertaken of relevant studies on pain medicine education for medical students published between January 1987 and May 2018 using PubMed, Medline, Excerpta Medica database (EMBASE), Education Resources Information Center (ERIC), and Google Scholar, and Best Evidence Medical Education (BEME) data bases. Results: Fourteen studies met the inclusion criteria. Evaluation of pain medicine curricula has been undertaken at 383 medical schools in Australia, New Zealand, the United States of America (USA), Canada, the United Kingdom (UK), and Europe. Pain medicine was mostly incorporated into medical courses such as anaesthesia or pharmacology, rather than presented as a dedicated pain medicine module. Ninety-six percent of medical schools in the UK and USA, and nearly 80% of medical schools in Europe had no compulsory dedicated teaching in pain medicine. On average, the median number of hours of pain content in the entire curriculum was 20 in Canada (2009), 20 in Australia and New Zealand (2018), 13 in the UK (2011), 12 in Europe (2012/2013), and 11 in the USA (2009). Neurophysiology and pharmacology pain topics were given priority by medical schools in all countries. Lectures, seminars, and case-based instruction were the teaching methods most commonly employed. When it was undertaken, medical schools mostly assessed student competency in pain medicine using written examinations rather than clinical assessments. Conclusions: This systematic review has revealed that pain medicine education at medical schools internationally does not adequately respond to societal needs in terms of the prevalence and public health impact of inadequately managed pain

Compatible finite element spaces for geophysical fluid dynamics

Compatible finite elements provide a framework for preserving important structures in equations of geophysical uid dynamics, and are becoming important in their use for building atmosphere and ocean models. We survey the application of compatible finite element spaces to geophysical uid dynamics, including the application to the nonlinear rotating shallow water equations, and the three-dimensional compressible Euler equations. We summarise analytic results about dispersion relations and conservation properties, and present new results on approximation properties in three dimensions on the sphere, and on hydrostatic balance properties

Alcohol-related mortality in deprived UK cities: worrying trends in young women challenge recent national downward trends

Background: Glasgow, the largest city in Scotland, has high levels of deprivation and a poor-health profile compared with other parts of Europe, which cannot be fully explained by the high levels of deprivation. The ‘excess’ premature mortality in Glasgow is now largely attributable to deaths from alcohol, drugs, suicide and violence. Methods: Alcohol-related mortality in Glasgow from 1980 to 2011 was examined relative to the equally deprived UK cities of Manchester and Liverpool with the aim of identifying differences across the cities, with respect to gender, age and birth cohort, that could help explain the ‘excess’ mortality in Glasgow. Results: In the 1980s, alcohol-related mortality in Glasgow was three times higher than in Manchester and Liverpool. Alcohol-related mortality increased in all three cities over the subsequent three decades, but a sharp rise in deaths in the early 1990s was unique to Glasgow. The increase in numbers of deaths in Glasgow was greater than in Manchester and Liverpool, but there was little difference in the pattern of alcohol-related deaths, by sex or birth cohort that could explain the excess mortality in Glasgow. The recent modest decrease in alcohol-related mortality was largely experienced by all birth cohorts, with the notable exception of the younger cohort (born between 1970 and 1979): women in this cohort across all three cities experienced disproportionate increases in alcohol-related mortality. Conclusions: It is imperative that this early warning sign in young women in the UK is acted on if deaths from alcohol are to reduce in the long term

Is there a global model of learning organizations? An empirical, cross-nation study

This paper develops and tests a learning organization model derived from HRM and dynamic capability literatures in order to ascertain the model’s applicability across divergent global contexts. We define a learning organization as one capable of achieving on-going strategic renewal, arguing based on dynamic capability theory that the model has three necessary antecedents: HRM focus, developmental orientation and customer-facing remit. Drawing on a sample comprising nearly 6000 organizations across 15 countries, we show that learning organizations exhibit higher performance than their less learning-inclined counterparts. We also demonstrate that innovation fully mediates the relationship between our conceptualization of the learning organization and organizational performance in 11 of the 15 countries we examined. It is the first time in our knowledge that these questions have been tested in a major, cross- global study, and our work contributes to both HRM and dynamic capability literatures, especially where the focus is the applicability of best practice parameters across national boundaries

The missing sinks: slip localization in faults, damage zones, and the seismic energy budget

No abstract available

Higher-order compatible finite element schemes for the nonlinear rotating shallow water equations on the sphere

We describe a compatible finite element discretisation for the shallow water equations on the rotating sphere, concentrating on integrating consistent upwind stabilisation into the framework. Although the prognostic variables are velocity and layer depth, the discretisation has a diagnostic potential vorticity that satisfies a stable upwinded advection equation through a Taylor-Galerkin scheme; this provides a mechanism for dissipating enstrophy at the gridscale whilst retaining optimal order consistency. We also use upwind discontinuous Galerkin schemes for the transport of layer depth. These transport schemes are incorporated into a semi-implicit formulation that is facilitated by a hybridisation method for solving the resulting mixed Helmholtz equation. We illustrate our discretisation with some standard rotating sphere test problems.Comment: accepted versio

Teamwork and organizational innovation: the moderating role of the HRM context

Evidence is accumulating on the role of teams in shaping a variety of business outcomes, but our knowledge on the effect of teamwork on organizational innovation is still evolving. This study examines whether the extent to which two staff groups are organized in teams (production staff and management/administrative staff) affects organizational innovation and whether human resource management (HRM) systems, which can be of facilitating or con- straining nature, enhance the teamwork/innovation relationships. Hypotheses were tested with lagged and longitudinal data derived from 18 to 45 organizations from the UK manufacturing sector. Results suggest that the more widespread the use of teamwork in organizations, the higher the level of organizational innovation. Furthermore, this effect depends, particularly for production teams, on the overall quality of the HRM systems that exist in their organizations. Teamwork/innovation relationships are further moderated (for management and administrative teams) by an HRM practice that provides teams with time for thoughtful reflection. Thus, HRM systems can be of more or less facilitating or constraining nature for teams in organizations