Systematic study of effect of cross-drafts and nozzle diameter on shield gas coverage

A shield gas flow rate of 15–20 L min21 is typically specified in metal inert gas welding, but is often adjusted to as high as 36 L min21 by welders in practice. Not only is this overuse of shield gas wasteful, but uncontrolled high gas flows can lead to significant turbulence induced porosity in the final weld. There is therefore a need to understand and control the minimum shield gas flow rate used in practical welding where cross-drafts may affect the coverage. Very low gas coverage or no shielding leads to porosity and spatter development in the weld region. A systematic study is reported of the weld quality achieved for a range of shield gas flow rates, cross-draft speeds and nozzle diameters using optical visualisation and numerical modelling to determine the shield gas coverage. As a consequence of the study, the shield gas flow has been reduced to 12 L min21 in production welding, representing a significant process cost saving and reduced environmental impact with no compromise to the final weld quality

The Role of Domestic Heat Pumps in Providing Flexibility to the UK Electricity System

Widespread adoption of residential heat pumps is predicted to create challenges for national and local electricity systems. Flexible operation of heat pumps could help smooth peak demand and better utilise renewables. Achieving these benefits involves many stakeholders from the heat pump and electricity sectors with different perspectives and expectations. This work brought together 52 experts from different parts of the UK system to discuss and debate the role of heat pump flexibility in a decarbonised electricity system in 2035. A co-production research model was adopted, designed to integrate diverse forms of knowledge and perspectives in the co-production of knowledge on heat pump flexibility. A series of participatory activities were undertaken including a one-day workshop. Elements of a common vision emerged, such as the anticipated widespread flexible operation of heat pumps as the cheapest way of running a heat pump and the likelihood of a highly automated and remote-controlled manner of operation. Disagreements and unknowns also emerged. This work aims to support stakeholders in planning for the social, technical and economic aspects of flexible heat pump operation in their own organisations

The Role of Domestic Heat Pumps in Providing Flexibility to the UK Electricity System

Widespread adoption of residential heat pumps is predicted to create challenges for national and local electricity systems. Flexible operation of heat pumps could help smooth peak demand and better utilise renewables. Achieving these benefits involves many stakeholders from the heat pump and electricity sectors with different perspectives and expectations. This work brought together 52 experts from different parts of the UK system to discuss and debate the role of heat pump flexibility in a decarbonised electricity system in 2035. A co-production research model was adopted, designed to integrate diverse forms of knowledge and perspectives in the co-production of knowledge on heat pump flexibility. A series of participatory activities were undertaken including a one-day workshop. Elements of a common vision emerged, such as the anticipated widespread flexible operation of heat pumps as the cheapest way of running a heat pump and the likelihood of a highly automated and remote-controlled manner of operation. Disagreements and unknowns also emerged. This work aims to support stakeholders in planning for the social, technical and economic aspects of flexible heat pump operation in their own organisations

Co-designing Infrastructures

Co-designing Infrastructures tells the story of a research programme designed to bring the power of engineering and technology into the hands of grassroots community groups, to create bottom-up solutions to global crises. Four projects in London are described in detail, exemplifying community collaboration with engineers, designers and scientists to enact urban change. The projects co-designed solutions to air pollution, housing, the water-energy-food nexus, and water management. Rich case-study accounts are underpinned by theories of participation, environmental politics and socio-technical systems. The projects at the heart of the book are grounded in specific settings facing challenges familiar to urban communities throughout the world. This place-based approach to infrastructure is of international relevance as a foundation for urban resilience and sustainability. The authors document the tools used to deliver this work, providing guidance for others who are working to deliver local technical solutions to complex social and environmental problems around the world. This is a book for engineers, designers, community organisers and researchers. Co-authored by researchers, it includes voices of community collaborators, their experiences, frustrations and aspirations. It explores useful theories about infrastructure, engineering and resilience from international academic research, and situates them in community-based co-design experience, to explain why bottom-up approaches are needed and how they might succeed

Clinical factors associated with relapse in depression in a sample of UK primary care patients who have been on long-term antidepressant treatment

BACKGROUND: This paper investigates whether age of onset of depression, duration of the last episode, number of episodes, and residual symptoms of depression and anxiety are associated with depression relapse in primary care patients who have been on long-term maintenance antidepressant treatment and no longer meet ICD10 criteria for depression. METHODS: An observational cohort using data from ANTLER (N = 478), a double-blind placebo-controlled trial. The primary outcome was time to relapse using the retrospective CIS-R. Participants were followed for 12 months. RESULTS: Primary outcome was available for 468 participants. Time to relapse in those with more than five previous episodes of depression was shorter, hazard ratio (HR) 1.84 (95% confidence interval [CI] 1.23-2.75) compared to people with two episodes; HR 1.57 (95% CI 1.01-2.43) after adjustment. The residual symptoms of depression at baseline were also associated with increased relapse: HR 1.05 (95% CI 1.01-1.09) and HR 1.06 (95% CI 1.01-1.12) in the adjusted model. There was evidence of reduced rate of relapse in older age of onset group: HR 0.86 (95% CI 0.78-0.95); HR attenuated after adjustment HR 0.91 (95% CI 0.81-1.02). There was no evidence of an association between duration of the current episode and residual anxiety symptoms with relapse. CONCLUSIONS: The number of previous episodes and residual symptoms of depression were associated with increased likelihood of relapse. These factors could inform joint decision making when patients are considering tapering off maintenance antidepressant treatment or considering other treatments to prevent relapse

Health improvement and educational attainment in secondary schools: complementary or competing priorities? Exploratory analyses from the School Health Research Network in Wales

Background. Implementing health improvement is often perceived as diverting resource away from schools’ core business, reflecting an assumption of a “zero-sum game” between health and education. There is some evidence that health behaviors may affect young people’s educational outcomes. However, associations between implementation of school health improvement and educational outcomes remains underinvestigated. Methods. The study linked school-level data on free school meal (FSM) entitlement, educational outcomes, and school attendance, obtained from government websites, with data from the School Environment Questionnaire (SEQ) on health improvement activity collected in Wales (2015/2016). Spearman’s rank correlation coefficients and linear regression models tested the extent of association between health improvement activity and attendance and educational outcomes. Results. SEQ data were provided by 100/115 network schools (87%), of whom data on educational performance were obtained from 97. The percentage of pupils entitled to FSM predicted most of the between-school variance in achievement and attendance. Linear regression models demonstrated significant positive associations of all measures of health improvement activity with attainment at Key Stage (KS) 3, apart from mental health education in the curriculum and organizational commitment to health. Student and parent involvement in planning health activities were associated with improved school attendance. There were no significant associations between health improvement and KS4 attainment. Conclusion. Implementing health improvement activity does not have a detrimental effect on schools’ educational performance. There is tentative evidence of the reverse, with better educational outcomes in schools with more extensive health improvement policies and practices. Further research should investigate processes by which this occurs and variations by socioeconomic status

Testing the ‘zero-sum game’ hypothesis: An examination of school health policies and practices and inequalities in educational outcomes

Background There is recognition that health and education are intrinsically linked through, for example, WHO's Health Promoting Schools (HPS) framework. Nevertheless, promoting health via schools is seen by some as a zero-sum game—ie, schools have nothing to gain, and may experience detriments to the core business of academic attainment because of focusing resources on health. Crucially, there is a paucity of evidence around the impacts of health and wellbeing policy and practice on attainment, with recent Cochrane reviews highlighting this gap. This study explored the zero-sum game hypothesis among schools with varying levels of deprivation—ie, the role of health and wellbeing interventions in schools in reducing or widening socioeconomic inequality in educational attainment. Methods Wales-wide, school-level survey data on health policies and practices, reflective of the HPS framework, were captured in 2016 using the School Environment Questionnaire. Questionnaire data were linked with routinely collected data on academic attainment. Primary outcomes included attendance and attainment at Key stages 3 (children aged 12–14 years) and 4 (15–16). Interaction terms were fitted to test whether there was an interaction between free school meals, overall HPS activity, and outcomes. Linear regression models were constructed separately for schools with high uptake of free school meals (>15% of pupils) and low uptake (<15%), adjusting for confounders. Findings The final analyses included 48 schools with low uptake of free school meals and 49 with high uptake. Significant interactions were observed between free school meals and overall HPS activity for Key stage 3 attainment (β=0·28, 95% CI 0·09–0·47) and attendance (0·05, 0·02–0·09), reflecting an association between health improvement activities and education outcomes among high, but not low, free school meal schools. There was no significant interaction for Key stage 4 attainment (0·18, −0·22 to 0·57). Interpretation Our findings did not support the zero-sum game hypothesis; in fact, among more deprived schools, there was a tendency for better attendance and attainment at Key stage 3. Schools must equip students with the skills required for good physical and mental health and wellbeing in addition to academic and cognitive skills. The study included a large, nationally representative sample of secondary schools; however, the cross-sectional nature has implications for causality