Computational fluid dynamics modelling of an entire synchronous generator for improved thermal management

This study is the first in a series dedicated to investigating the airflow and thermal management of electrical machines. Owing to the temperature dependent resistive losses in the machine's windings, any improvement in cooling provides a direct reduction in losses and an increase in efficiency. This study focuses on the airflow which is intrinsically linked to the thermal behaviour of the machine as well as the windage power consumed to drive the air through the machine. A full computational fluid dynamics (CFD) model has been used to analyse the airflow around all major components of the machine. Results have been experimentally validated and investigated. At synchronous speed the experimentally tested mass flow rate and windage torque were under predicted by 4% and 7%, respectively, by the CFD. A break-down of torque by component shows that the fan consumes approximately 87% of the windage torque

Bullying and sexual abuse and their association with harmful behaviours, antidepressant use and health-related quality of life in adulthood: a population-based study in South Australia

BACKGROUND:Few representative sample studies have reported estimates of bullying and sexual abuse in Australia. By using face-to-face interviews and self-labelling questions, we investigated the prevalence of these forms of abuse and their relationship with current harmful behaviours (smoking dependence, excessive alcohol intake, binge eating), antidepressant use, and the physical (PCS) and mental (MCS) components of health-related quality of life. METHODS:This study was a population-based survey that investigated 2873 South Australians in 2015 (48.8 ± 18.1 years; 49.3% males). Bullying and sexual abuse (age of onset and duration) and their outcomes were investigated through household interviews. Associations were adjusted for sociodemographic variables by using regression models. RESULTS:45.6% (95% CI 43.3-47.9) of the participants were bullied, and 10.4% (95% CI 9.1-11.9) sexually abused; 7.3% (95% CI 6.2-8.5) reported experiencing both forms of abuse. Moreover, 15.8% of those bullied and 15.0% of those sexually abused suffered from these forms of abuse for > 24 months. Smoking dependence (7.8%) was twice as frequent among those who experienced bullying for > 24 months or when sexual abuse occurred in childhood ( 24 months. Binge eating (8.1%) was more frequent among those bullied or sexually abused in adulthood, but duration did not show a clear pattern. Antidepressant use was up to four times more likely, and PCS or MCS lower among those who were bullied or sexually abused, independent of when these forms of abuse started or their duration. The cumulative adverse relationship of bullying and sexual abuse with the investigated outcomes was more evident for smoking dependence, binge eating, PCS, and MCS than for antidepressant use, but no association was observed with alcohol intake. CONCLUSIONS:The use of self-labelling questions to investigate sensitive areas such as bullying and sexual abuse in a survey is feasible. Such questions provided estimates that are consistent with findings from studies using more detailed instruments. Bullying and sexual abuse have an additive adverse association with various outcomes. Identifying survivors of both forms of abuse is important to avoid more serious consequences.David Alejandro González-Chica, Julio Licinio, Michael Musker, Mali Wong, Jacqueline Bowden, Phillipa Hay, Catherine Chittleborough and Nigel Stock

The transformative potential of international service-learning at a university with a Christian foundation in the UK

This article draws upon the findings of a study at Liverpool Hope University (LHU) into the transformative nature of International Service-Learning (ISL) experiences for student participants. This research is concerned with the implications of these findings for professional practice, in particular how ISL is constructed in Higher Education policy and practice. Recognising the problematic nature of this endeavor, this article responds to a call for discussion around pedagogical approaches underpinning counter-cultural and critical service programmes aligned with the radical principles of the Catholic social teaching. This study is grounded in a holistic conceptualisation of transformative learning that demands looking beyond an epistemological process that involves shifts in worldview and habits of mind to an ontological process that accounts for changes to our being in the world. It investigated how LHU students describe their ongoing experience of ISL and explored the conditions for learning and the associated transformative processes and outcomes in this context. Data analysis involved phenomenological description, constant comparative thematic analysis followed by a critical, hermeneutical analysis. This article will explicate the themes of moral and spiritual learning that emerged as part of a broader framework. In particular, it was found that the development of authentic relationships between travelling companions, accompanying tutors and partners overseas is central to learning that is reciprocated and provides a model of the transformative process in this context. This article concludes that this presents a pedagogical approach grounded in social justice that enables ISL to reach its transformative potential

Long term intrinsic cycling in human life course antibody responses to influenza A(H3N2): an observational and modeling study

Background: Over a life course, human adaptive immunity to antigenically mutable pathogens exhibits competitive and facilitative interactions. We hypothesize that such interactions may lead to cyclic dynamics in immune responses over a lifetime. Methods: To investigate the cyclic behavior, we analyzed hemagglutination inhibition titers against 21 historical influenza A(H3N2) strains spanning 47 years from a cohort in Guangzhou, China, and applied Fourier spectrum analysis. To investigate possible biological mechanisms, we simulated individual antibody profiles encompassing known feedbacks and interactions due to generally recognized immunological mechanisms. Results: We demonstrated a long-term periodicity (about 24 years) in individual antibody responses. The reported cycles were robust to analytic and sampling approaches. Simulations suggested that individual-level cross-reaction between antigenically similar strains likely explains the reported cycle. We showed that the reported cycles are predictable at both individual and birth cohort level and that cohorts show a diversity of phases of these cycles. Phase of cycle was associated with the risk of seroconversion to circulating strains, after accounting for age and pre-existing titers of the circulating strains. Conclusions: Our findings reveal the existence of long-term periodicities in individual antibody responses to A(H3N2). We hypothesize that these cycles are driven by preexisting antibody responses blunting responses to antigenically similar pathogens (by preventing infection and/or robust antibody responses upon infection), leading to reductions in antigen-specific responses over time until individual's increasing risk leads to an infection with an antigenically distant enough virus to generate a robust immune response. These findings could help disentangle cohort effects from individual-level exposure histories, improve our understanding of observed heterogeneous antibody responses to immunizations, and inform targeted vaccine strategy

Professionalism, Golf Coaching and a Master of Science Degree: A commentary

As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues

The impact of a residential camp on grandchildren raised by grandparents: Grandparents’ perspectives

This research aimed to investigate grandparents’ perspectives on the impact of Leadership and Respite Camps, designed for children being raised by their grandparents, on their grandchildren. In-depth interviews were conducted with 34 grandparents whose grandchildren had participated in 1 of 3 camps held between September 2018 and January 2019, in Perth and the south-west of Western Australia. Findings highlighted how grandcarers’ perceived the camps created unique opportunities for grandchildren to share their experiences in a safe and supportive environment. Grandparents reported significant psychosocial benefits to their grandchild, including feeling they fitted in with their peers and were not alone in experiencing a difficult childhood and adolescence; gaining perspective on their situation and developing a new appreciation for their grandparents; being able to emotionally ‘unblock’ traumatic memories through the sharing of experiences in a safe and supportive camp environment; developing resilience, confidence and self-esteem through participation in challenging activities; and making new friendships. This research provides strong evidence that Leadership and Respite Camps designed for grandchildren being raised by their grandparents deliver significant psychosocial benefits to grandchildren, and offers a solid foundation to advocate for regular camps to address the needs of grandparent-led families

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017

Background Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health