935 research outputs found
The atomisation of detergent slurries
A study was made to determine the conditions under which the optimum droplet size distribution (ie., narrowest size range with a minimum of fines and over-sized agglomerates), is generated in sprays from centrifugal pressure nozzles. A range of non-Newtonian detergent slurries were tested but the results are of wider application and parallel work was undertaken with water, ionic solutions and chalk slurries. Six centrifugal pressure nozzles were used and the drop-size distributions correlated as a function of fluid properties, pressure, fiowrate, feed temperature, and nozzle characteristics. Measurements were made using a Malvern Particle Size Anayser slung across a specially-designed transparent tower section of approximately 1.2m diameter in order to reduce obscuration caused by the spray and improve existing droplet sizing techniques. The results obtained were based upon the Rosin-Rammler distribution model and the Size Analyser provided a direct print-out of size distribution and the parameters characterising it. A Spraying System nozzle, AAASSTC8-8, produced the optimum spray distribution with the detergent slurry at a temperature of 60°C whilst operating at 1200 psi. With other fluids the Delevan 2.2SJ nozzle produced the optimum spray distribution operating at 1200 psi but with the Spraying Systems nozzles there was no clear-cut optimum set of conditions, ie. the nozzle and pressure varied depending upon the fluid being sprayed. The mechanisms of liquid sheet break-up and droplet dispersion were investigated in specially-constructed, scaled-up, transparent nozzles. A mathematical model of centrifugal pressure nozzle atomisation was developed based upon fundamental operating parameters rather than resorting to empirical correlations. This enabled theoretical predictions to be made over a wide range of operating conditions and nozzle types. The model predictions for volumetric fiowrate, liquid sheet length and air core diameter showed good agreement with the experimentally determined results. However, the model predicted smaller droplet sizes than were produced experimentally due to inaccuracies identified in the initial assumptions
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UK Research Information Shared Service (UKRISS) Final Report, July 2014
The reporting of research information is a complex and expensive activity for research organisations (ROs). There is little alignment between funders of the reporting requests made to institutions and requests made to individual researchers about their research outputs and outcomes. This inevitably results in duplication and increased costs across the sector, whilst limiting the potential sharing and reuse of the information. The UK Research Information Shared Service (UKRISS) project conducted a feasibility and scoping study for the reporting of research information at a national level based on CERIF (Common European Research Information Format), with the objective of increasing efficiency, productivity and quality across the sector. The aim was to define and prototype solutions which are compelling, easy to use, have a low entry barrier, and support innovative information sharing and benchmarking. CERIF has emerged as the preferred format for expressing research information across Europe. To date, CERIF has been piloted for specific applications, but not as a format for reporting requirements across all UK ROs. The final report presents the work carried out by the UKRISS project, including requirements gathering, modelling and prototyping, as well as recommendation for sustainability. UKRISS was divided into two phases. Phase 1, mapping the reporting landscape, ran from March 2012 to December 2012. Phase 2, exploring delivery of potential solutions, began in February 2013 and ended in December 2013
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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
Drug prescriptions and dementia incidence: a medication-wide association study of 17000 dementia cases among half a million participants
Previous studies have suggested that some medications may influence dementia risk. We conducted a hypothesis-generating medication-wide association study to investigate systematically the association between all prescription medications and incident dementia. We used a population-based cohort within the Secure Anonymised Information Linkage (SAIL) databank, comprising routinely-collected primary care, hospital admissions and mortality data from Wales, UK. We included all participants born after 1910 and registered with a SAIL general practice at ≤60 years old. Follow-up was from each participant's 60th birthday to the earliest of dementia diagnosis, deregistration from a SAIL general practice, death or the end of 2018. We considered participants exposed to a medication if they received ≥1 prescription for any of 744 medications before or during follow-up. We adjusted for sex, smoking and socioeconomic status. The outcome was any all-cause dementia code in primary care, hospital or mortality data during follow-up. We used Cox regression to calculate hazard ratios and Bonferroni-corrected p values. Of 551 344 participants, 16 998 (3%) developed dementia (median follow-up was 17 years for people who developed dementia, 10 years for those without dementia). Of 744 medications, 221 (30%) were associated with dementia. Of these, 217 (98%) were associated with increased dementia incidence, many clustering around certain indications. Four medications (all vaccines) were associated with a lower dementia incidence. Almost a third of medications were associated with dementia. The clustering of many drugs around certain indications may provide insights into early manifestations of dementia. We encourage further investigation of hypotheses generated by these results. [Abstract copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.
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