DUCTILITY OF 304 STAINLESS STEEL UNDER PULSED UNIAXIAL LOADING

The enhanced ductility that 304 stainless steel is exhibited under pulsed loading (Zhang, 2009) is investigated here using a combination of experiments and analysis. The simplest loading case, i.e., uniaxial tension, was selected to avoid the complicating effects of multiaxial stress states and/or contact and friction with a rigid die. Three types of tensile tests were performed: monotonic, pulsed and hold. For a range of strain rates, the pulsed and the hold tests exhibited different elongation-to-fracture from the monotonic tests. Digital image correlation and infrared thermography were employed to further probe this behavior. It was discovered that since the pulsed tests lasted longer than the corresponding monotonic ones (i.e., those with the same loading speed) but the total plastic work expended was comparable, milder deformation-induced heating developed in the pulsed tests. Since the resulting temperature gradients act as imperfections that trigger the localization of deformation, the enhanced elongation-to-fracture in the pulsed tests was attributed to the milder gradients that developed. Subsequently, a special isothermal tension test was used to de-couple the mechanical from the thermal behavior of the material and was repeated at various strain rates and temperatures. The material properties determined from these tests were used as input to coupled, thermomechanical finite element simulations of the experiments. Despite numerous simplifications, such as constant thermal properties with temperature, the simulations captured the essential physics of the problem and yielded very close predictions of the elongation-to-fracture observed in the experiments

Recyclable structural composites for marine renewable energy

The InterReg SeaBioComp project will develop and deliver demonstrators using innovative bio-based thermoplastic composite materials with mechanical properties comparable to conventional oil-based composites, durability tailored to the specific application (2 to >20 years), recycling potential, reduced CO2 emissions and reduced microplastic and ecotoxic impact in the marine environment. The University of Plymouth is investigating to use of manufacture by monomer infusion under flexible tooling (MIFT) with in situ polymerisation to produce natural, or glass, fibre reinforced structural composites. Following an extensive literature survey, the monomer selection has suggested two potential matrix materials: poly(methyl methacrylate) (PMMA) and poly(L-lactide) (PLA). The conference paper will present the progress in measurement of the composite mechanical properties and correlation to models predicting the material performance

Who Wears the MAGA Hat? Racial Beliefs and Faith in Trump

On the basis of a 2019 YouGov survey of white respondents (n = 734), the impact of racial beliefs on support for Donald Trump was explored. The analysis revealed that in addition to racial resentment, white nationalism—a desire to keep the United States white demographically and culturally—was strongly related to faith in Trump. Analyses based on a 2019 Amazon Mechanical Turk survey yielded similar results and also showed that white nationalism increased willingness to wear a MAGA hat. Future research on the political consequences of racial beliefs should focus on what whites think not only of blacks but also of themselves

Living alone, loneliness and lack of emotional support as predictors of suicide and self-harm: A nine-year follow up of the UK Biobank cohort

Background: The association between loneliness and suicide is poorly understood. We investigated how living alone, loneliness and emotional support were related to suicide and self-harm in a longitudinal design. Methods: Between 2006 and 2010 UK Biobank recruited and assessed in detail over 0.5 million people in middle age. Data were linked to prospective hospital admission and mortality records. Adjusted Cox regression models were used to investigate relationships between living arrangements, loneliness and emotional support, and both suicide and self-harm as outcomes. Results: For men, both living alone (Hazard Ratio (HR) 2.16, 95%CI 1.51-3.09) and living with non-partners (HR 1.80, 95%CI 1.08-3.00) were associated with death by suicide, independently of loneliness, which had a modest relationship with suicide (HR 1.43, 95%CI 0.1.01-2.03). For women, there was no evidence that living arrangements, loneliness or emotional support were associated with death by suicide. Associations between living alone and self-harm were explained by health for women, and by health, loneliness and emotional support for men. In fully adjusted models, loneliness was associated with hospital admissions for self-harm in both women (HR 1.89, 95%CI 1.57-2.28) and men (HR 1.74, 95%CI 1.40-2.16). Limitations: Loneliness and emotional support were operationalized using single item measures. Conclusions: For men - but not for women - living alone or living with a non-partner increased the risk of suicide, a finding not explained by subjective loneliness. Overall, loneliness may be more important as a risk factor for self-harm than for suicide. Loneliness also appears to lessen the protective associations of cohabitation

Mental health in UK Biobank: development, implementation and results from an online questionnaire completed by 157 366 participants

Background UK Biobank is a well-characterised cohort of over 500 000 participants that offers unique opportunities to investigate multiple diseases and risk factors. Aims An online mental health questionnaire completed by UK Biobank participants was expected to expand the potential for research into mental disorders. Method An expert working group designed the questionnaire, using established measures where possible, and consulting with a patient group regarding acceptability. Case definitions were defined using operational criteria for lifetime depression, mania, anxiety disorder, psychotic-like experiences and self-harm, as well as current post-traumatic stress and alcohol use disorders. Results 157 366 completed online questionnaires were available by August 2017. Comparison of self-reported diagnosed mental disorder with a contemporary study shows a similar prevalence, despite respondents being of higher average socioeconomic status than the general population across a range of indicators. Thirty-five per cent (55 750) of participants had at least one defined syndrome, of which lifetime depression was the most common at 24% (37 434). There was extensive comorbidity among the syndromes. Mental disorders were associated with high neuroticism score, adverse life events and long-term illness; addiction and bipolar affective disorder in particular were associated with measures of deprivation. Conclusions The questionnaire represents a very large mental health survey in itself, and the results presented here show high face validity, although caution is needed owing to selection bias. Built into UK Biobank, these data intersect with other health data to offer unparalleled potential for crosscutting biomedical research involving mental health

Mental health in UK Biobank - development, implementation and results from an online questionnaire completed by 157 366 participants: a reanalysis

Background UK Biobank is a well-characterised cohort of over 500 000 participants including genetics, environmental data and imaging. An online mental health questionnaire was designed for UK Biobank participants to expand its potential. Aims Describe the development, implementation and results of this questionnaire. Method An expert working group designed the questionnaire, using established measures where possible, and consulting a patient group. Operational criteria were agreed for defining likely disorder and risk states, including lifetime depression, mania/hypomania, generalised anxiety disorder, unusual experiences and self-harm, and current post-traumatic stress and hazardous/harmful alcohol use. Results A total of 157 366 completed online questionnaires were available by August 2017. Participants were aged 45–82 (53% were ≥65 years) and 57% women. Comparison of self-reported diagnosed mental disorder with a contemporary study shows a similar prevalence, despite respondents being of higher average socioeconomic status. Lifetime depression was a common finding, with 24% (37 434) of participants meeting criteria and current hazardous/harmful alcohol use criteria were met by 21% (32 602), whereas other criteria were met by less than 8% of the participants. There was extensive comorbidity among the syndromes. Mental disorders were associated with a high neuroticism score, adverse life events and long-term illness; addiction and bipolar affective disorder in particular were associated with measures of deprivation. Conclusions The UK Biobank questionnaire represents a very large mental health survey in itself, and the results presented here show high face validity, although caution is needed because of selection bias. Built into UK Biobank, these data intersect with other health data to offer unparalleled potential for crosscutting biomedical research involving mental health

Thermoplastic matrix systems for large marine structures

Almost all large fibre composite structures used in the marine environment use a thermoset resin matrix. These materials have excellent durability in the sea, but are difficult to dispose of at end-of-life. After a rigorous selection process, methyl methacrylate and lactide monomers have been identified as potential thermoplastic matrix systems which can be manufactured using in situ polymerisation during monomer infusion under flexible tooling. The presentation will address manufacturing issues (acrylic is a “drop in” for polyester resin, but lactide requires heating systems), and end of life (acrylic is lower in the recycling hierarchy). This work was conducted within the SeaBioComp project which has received funding from Interreg 2 Seas Mers Zeeën programme 2014–2020 co-funded by the European Regional Development Fund under subsidy contract No. 2S06-006

Genetic Variation in the ASTN2 Locus in Cardiovascular, Metabolic and Psychiatric Traits: Evidence for Pleiotropy Rather Than Shared Biology

Background: The link between cardiometabolic and psychiatric illness has long been attributed to human behaviour, however recent research highlights shared biological mechanisms. The ASTN2 locus has been previously implicated in psychiatric and cardiometabolic traits, therefore this study aimed to systematically investigate the genetic architecture of ASTN2 in relation to a wide range of relevant traits. Methods: Baseline questionnaire, assessment and genetic data of 402111 unrelated white British ancestry individuals from the UK Biobank was analysed. Genetic association analyses were conducted using PLINK 1.07, assuming an additive genetic model and adjusting for age, sex, genotyping chip, and population structure. Conditional analyses and linkage disequilibrium assessment were used to determine whether cardiometabolic and psychiatric signals were independent. Results: Associations between genetic variants in the ASTN2 locus and blood pressure, total and central obesity, neuroticism, anhedonia and mood instability were identified. All analyses support the independence of the cardiometabolic traits from the psychiatric traits. In silico analyses provide support for the central obesity signal acting through ASTN2, however most of the other signals are likely acting through other genes in the locus. Conclusions: Our systematic analysis demonstrates that ASTN2 has pleiotropic effects on cardiometabolic and psychiatric traits, rather than contributing to shared pathology