63 research outputs found

    Experimental and modelling investigation of the deformation, drag and break-up of drizzle droplets subjected to strong aerodynamics forces in relation to SLD aircraft icing

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    The distortion, drag and break-up of drizzle droplets subjected to strong aerodynamic forces was investigated to understand the pre-impact behaviour of droplets in aircraft icing from supercooled freezing drizzle. The objective was to obtain a formulation and data for the drag properties of droplets distorted by the aerodynamic forces, which were beyond the scope of available experimental and modelling methods. A practical and efficient semi-empirical computer model was developed for small water droplets in air, 100ĂŽÂŒm < D < 500ĂŽÂŒm, at moderate Reynolds numbers, 350 < Re < 1500, and high Weber numbers 3 < We < 20. This used available experimental terminal velocity data for free-falling droplets, extrapolated to higher Weber numbers, and the numerical solution for sessile droplets on a horizontal unwettable surface, with corrections for the Reynolds number. A theory for bag break-up was developed based on the Rayleigh-Taylor instability of the windward droplet surface. The critical Bond number was 13.7, with a critical diameter of 10.1mm for free-falling water droplets, compared to the experimental value of 10mm diameter. The equivalent Weber number was 14.2 for free falling water droplets. Aerodynamic interaction between the closely-spaced droplets from a vibrating nozzle droplet generator resulted in irregular spacing and coalescence of droplets. In an alternative design a laminar jet impinged on a rotating slotted disk to achieve the necessary droplet spacing, but the significant size variability of the droplets degraded the experimental measurements. High-speed videos, to 50,000pps, and photographs were obtained of droplet distortion, break-up, coalescence and splashes using a high-intensity LED strobe flash. A specially-designed convergent wind tunnel was developed for experimental measurements, to validated the drag model and provide data for droplets distorted by aerodynamic forces. The convergent profile produced a rapidly-increasing Weber number at a sufficiently slow rate to avoid transients or droplet vibrations. A special instrument was developed, with three equispaced parallel laser beams and photo detectors, to determine the droplet velocity and acceleration. Droplet drag characteristics were measured up to Weber numbers of 16. Good agreement was obtained between droplet drag model and experimental results. The greatest discrepancy was about 20% at a Weber number of about 8.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Evaluation of an Australian Health Literacy Program Delivered in Adult Education Settings.

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    BACKGROUND: Adult education targeting health literacy (HL) may bring added value in the form of improved health. OBJECTIVE: This study evaluated the effects of a HL program as part of an adult education curriculum for adults with low literacy and numeracy. METHODS: This was a partial-cluster randomized controlled trial among 308 adults enrolled in basic education programs in Australia. Of the 308 participants, 141 (46%) were randomized to either the standard program (language, literacy, and numeracy [LLN]), or the HL intervention (LLN with embedded health content); the remainder (n = 167) were allocated to standard intervention programs by the education provider at the class level. The main outcomes were functional HL, self-reported confidence, patient activation, generic HL (ie, HLQ, health knowledge, and self-reported health behavior). Data were collected at baseline, immediately after, and at 6 months post-intervention. KEY RESULTS: Of the 308 participants, 71% had limited literacy and 60% spoke a language other than English at home. Both interventions benefited participants, with improvements from baseline to immediate follow up on individual-level functional HL (e.g., reading a thermometer; HL group 18.4% vs. standard group 7.2%; p = .001), confidence (HL group 0.34 vs. standard group 0.06; p = .014) and health literacy questionnaire (HLQ) subscales. At 6 months, improvements in confidence (p < .001) and some HLQ measures were retained. A consistent pattern of increased improvement in the HL program was observed compared to the standard program, although only some measures reached statistical significance: reading a food label (HL group 6.03/10 correct vs. standard group 5.49/10 correct; p = .022); confidence (p = .008); ability to actively manage health (HLQ) (p = .017), and health knowledge at 6 months (HL group 68% vs. standard group 60% correct, p = .052). HL participants reported being more likely to share course information and rated the program more useful to understand their health. CONCLUSIONS: Improving language, literacy, and numeracy generally has potential public health benefits that are retained at 6 months. Integrating health content adds further value to adult basic learning, is feasible, and potentially scalable. [HLRP: Health Literacy Research and Practice. 2019;3(Suppl.):S42-S57.]. PLAIN LANGUAGE SUMMARY: We compared the effect of an adult education-based health literacy (HL) program versus a standard language, literacy, and numeracy program on students' HL skills and psychosocial outcomes. Although students in both trial arms improved their skills, students in the HL program had better outcomes with higher HL, greater confidence, and higher health knowledge scores at 6 months

    Learners' experience and perceived impact of a health literacy program in adult basic education: a qualitative study.

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    Objectives and importance of the study: Adult literacy programs aim to empower learners to participate more effectively in everyday life. This includes programs with health content embedded in curricula to target health literacy. Adult learners who attend these programs represent a heterogeneous population, but include a high proportion of hard-to-reach or socially disadvantaged groups in terms of age, ethnicity, educational background, language and prevalence of learning disabilities. In 2014, we conducted a cluster-randomised controlled trial of a health literacy program in adult basic education classes across New South Wales, Australia. This paper reports findings from a qualitative study exploring learners' experience of the course and its perceived impact on their lives, as well as their understanding and confidence about health. STUDY TYPE:Qualitative interview study. METHOD:We conducted semistructured interviews as part of the evaluation of the 18-week health literacy program, with participants purposively recruited from six health literacy classes (n = 22). Researchers trained in qualitative methods interviewed adult learners either face to face or over the phone using a topic guide. Data was analysed using the Framework method, a matrix-based approach to thematic analysis. RESULTS:The majority of interviewees were female, lived in metropolitan areas and were from non-English-speaking backgrounds. Most had existing self-reported health problems and inadequate functional health literacy. Most participants described positive impacts of the health literacy course on their language, literacy and numeracy skills, functional health literacy skills, and health knowledge. They also reported being able to translate this into health actions including interacting with providers, accessing and using healthcare, and managing health and illness (e.g. making healthier food choices). Learners also described positive social outcomes of the course, including feelings of connectedness and interpersonal trust within a new network of learners, and reported sharing new knowledge with others in their communities. CONCLUSIONS:The findings add value to existing limited evidence that has demonstrated the untapped potential of adult basic education to develop health literacy skills among socially disadvantaged groups. Learners valued the opportunity to share experiences in structured group learning, and reported confidence to transfer new knowledge into their home and wider social network

    Identifying important breast cancer control strategies in Asia, Latin America and the Middle East/North Africa

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    Background: Breast cancer is the most frequent cause of cancer death in women worldwide, but global disparities in breast cancer control persist, due to a lack of a comprehensive breast cancer control strategy in many countries. Objectives: To identify and compare the need for breast cancer control strategies in Asia, Latin America and the Middle East/North Africa and to develop a common framework to guide the development of national breast cancer control strategies. Methods: Data were derived from open-ended, semi-structured interviews conducted in 2007 with 221 clinicians, policy makers, and patient advocates; stratified across Asia (n = 97), Latin America (n = 46), the Middle East/North Africa (ME/NA) (n = 39) and Australia and Canada (n = 39). Respondents were identified using purposive and snowballing sampling. Interpretation of the data utilized interpretive phenomenological analysis where transcripts and field notes were coded and analyzed and common themes were identified. Analysis of regional variation was conducted based on the frequency of discussion and the writing of the manuscript followed the RATS guidelines. Results: Analysis revealed four major themes that form the foundation for developing national breast cancer control strategies: 1) building capacity; 2) developing evidence; 3) removing barriers; and 4) promoting advocacy - each specified across five sub-ordinate dimensions. The propensity to discuss most dimensions was similar across regions, but managing advocacy was discussed more frequently (p = 0.004) and organized advocacy was discussed less frequently (p \u3c 0.001) in Australia and Canada. Conclusions: This unique research identified common themes for the development of breast cancer control strategies, grounded in the experience of local practitioners, policy makers and advocacy leaders across diverse regions. Future research should be aimed at gathering a wider array of experiences, including those of patients
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