Effect of mutual coupling on torque production in switched reluctance motors

In many cases, the normal operation of switched reluctance machines requires excitation of two or more phases simultaneously. When multiple phases are conducting simultaneously, the flux paths from each phase will overlap, which may lead to localized saturation. In such cases, the flux linkage must be considered a function not just of the current in the test winding but of all excited windings. The degree of mutual coupling between phases influences the per-phase magnetization curves and torque characteristics. In machines with even phase numbers, the degree of mutual coupling between phases varies due to discontinuities in the phase polarity arrangement. From nonlinear finite element simulations, it is possible to compare the i - loop diagrams under single-phase and multiphase excitations, and hence the torque produced. The mutual flux linkage from each phase can be calculated separately for each rotor position using the frozen permeability method, to further analyze the mutual coupling effects. For a given excitation current profile, the torque can be maximized by careful arrangement of the phase polarities

Learning as an outcome of involvement in research : what are the implications for practice, reporting and evaluation?

Abstract Public involvement in research has evolved over the last two decades in a culture dominated by the principles of evidence-based medicine. It is therefore unsurprising that some researchers have applied the same thinking to involvement, particularly to involvement in research projects. This may explain why they tend to conceptualise involvement as an intervention, seek to evaluate its impact in the same way that treatments are tested, highlight the need for an evidence-base for involvement, and use the language of research to describe its practice and report its outcomes. In this article we explore why this thinking may be unhelpful. We suggest an alternative approach that conceptualises involvement as ‘conversations that support two-way learning’. With this framing, there is no ‘method’ for involvement, but a wide range of approaches that need to be tailored to the context and the needs of the individuals involved. The quality of the interaction between researchers and the public becomes more important than the process. All parties need to be better prepared to offer and receive constructive criticism and to engage in constructive conflict that leads to the best ideas and decisions. The immediate outcomes of involvement in terms of what researchers learn are subjective (specific to the researcher) and unpredictable (because researchers don’t know what they don’t know at the start). This makes it challenging to quantify such outcomes, and to carry out comparisons of different approaches. On this basis, we believe obtaining ‘robust evidence’ of the outcomes of involvement in ways that are consistent with the values of evidence-based medicine, may not be possible or appropriate. We argue that researchers’ subjective accounts of what they learnt through involvement represent an equally valid way of knowing whether involvement has made a difference. Different approaches to evaluating and reporting involvement need to be adopted, which describe the details of what was said and learnt by whom (short term outcomes), what changes were made as a result (medium term outcomes), and the long-term, wider impacts on the research culture and agenda. Sharing researchers’ personal accounts may support wider learning about how involvement works, for whom and when

Electives in undergraduate medical education: AMEE Guide No. 88

This Guide outlines the scope and potential roles an elective can contribute to undergraduate medical training and identifies ways to maximize learning opportunities, including within global health. The types of educational activity available for electives range from meeting individual educational need through to exploration of potential career pathways, with many factors influencing choice. Key areas of organization underpinning a successful elective before, during and after the placement include developing clarity of the intended educational outcomes as well as addressing practicalities such as travel and accommodation. Risk management including the implications for the participating schools as well as the student and their elective supervisors is crucial. This Guide would not be complete without some discussion around ethics and professional conduct during an elective, with consideration of the impact of elective placements, particularly in low-middle income countries

Health and Crime Outcomes During and Following Prison Release Among a Prospective Cohort of Men With a History of Injecting Drug Use

People with a history of substance use, particularly injecting drug use, are overrepresented among people in prison. The aim of this thesis was to examine the health outcomes during periods of imprisonment and the health and crime outcomes within 12 months following release from prison among a prospective cohort of men with a history of injecting drug use in Victoria, Australia. This thesis shows there is a need to increase resources and reallocate those current available toward an evidence-based and health-oriented response for people engaging in non-violent and drug-related crime