Electro-luminescence and associated two carrier effects in cadmium sulphide

The properties of cad sulphide are such that the material has some potential for use in the semiconductor industry. The potential has so far not been realised because of the difficulty of preparing crystals with controlled properties. In order to improve the material available, much work has been carried out to identify and measure the parameters of the defects in the material. The study of double injection phenomena is one tool which enables defects to be investigated. During the work which forms the basis of this thesis, a large number of double injection devices have been fabricated from crystals grown by sublimation of CdS powder in a stream of argon. The devices have been studied at temperatures in the range 90 to 300 ºk and at temperatures below about 150 ºk visible green light is emitted when currents above about 5 mA flow. The light is due to recombination in the bulk and on the surface of the crystals, A comparison of the photo-, electro-, and cathodo- luminescent spectra has been made. The electrical measurements reveal that the current flow is governed by a class IT centre located 0.98 eV above the valence band. The presence of this centre leads to a switching effect which is such that the device can be turned on when a voltage pulse or a pulse of light is applied to the device when biased below threshold. When pulsed voltages are applied, the current pulse has a step in it due to a fraction of the class II centres capturing electrons while the pulse is off. The maximum frequency of sine wave modulation of the light has been found to be less than 1 megacycle so that the CdS device is unlikely to compete with injection lasers in other materials as a source of light for optical telecommunication systems

The health and sport engagement (HASE) intervention and evaluation project: protocol for the design, outcome, process and economic evaluation of a complex community sport intervention to increase levels of physical activity.

INTRODUCTION: Sport is being promoted to raise population levels of physical activity for health. National sport participation policy focuses on complex community provision tailored to diverse local users. Few quality research studies exist that examine the role of community sport interventions in raising physical activity levels and no research to date has examined the costs and cost-effectiveness of such provision. This study is a protocol for the design, outcome, process and economic evaluation of a complex community sport intervention to increase levels of physical activity, the Health and Sport Engagement (HASE) project part of the national Get Healthy Get Active programme led by Sport England. METHODS AND ANALYSIS: The HASE study is a collaborative partnership between local community sport deliverers and sport and public health researchers. It involves designing, delivering and evaluating community sport interventions. The aim is to engage previously inactive people in sustained sporting activity for 1×30 min a week and to examine associated health and well-being outcomes. The study uses mixed methods. Outcomes (physical activity, health, well-being costs to individuals) will be measured by a series of self-report questionnaires and attendance data and evaluated using interrupted time series analysis controlling for a range of sociodemographic factors. Resource use will be identified and measured using diaries, interviews and records and presented alongside effectiveness data as incremental cost-effectiveness ratios and cost-effectiveness acceptability curves. A longitudinal process evaluation (focus groups, structured observations, in-depth interview methods) will examine the efficacy of the project for achieving its aim using the principles of thematic analysis. ETHICS AND DISSEMINATION: The results of this study will be disseminated through peer-reviewed publications, academic conference presentations, Sport England and national public health organisation policy conferences, and practice-based case studies. Ethical approval was obtained through Brunel University London's research ethics committee (reference number RE33-12)

Domestic thermal upgrades, community action and energy saving: a three-year experimental study of prosperous households

A three-year field experiment was conducted with 185 prosperous households to assess whether behavioural interventions by a community environmental group during and after thermal upgrades (cavity wall and/or loft insulation) can achieve reductions in households’ energy use, including reductions in direct and indirect rebound. The engineering interventions on the thermal efficiency of dwellings appear effective in reducing energy use in both treatment and control groups: a direct rebound effect is estimated to be at most 40 per cent from the engineering interventions. However, across a range of measures of energy use, we observe no significant effect of the community behavioural intervention across the total lifetime of the project. Qualitative data collected on similar community groups suggests substantial constraints on their capacity to realise reductions in energy use amongst households

A systematic overview of reviews of the effectiveness and cost effectiveness of interventions to promote healthy lifestyle behaviours in people living with or beyond cancer

An overview of systematic reviews synthesised evidence on the relationship between smoking, physical activity, dietary behaviours and alcohol consumption and important outcomes for people living with and beyond cancer. That review demonstrated that some lifestyle behaviours may be associated with important outcomes in people living with and beyond cancer (PLWBC). However it did not inform us of whether specifically delivering interventions aimed at modifying lifestyle behaviours effectively improve outcomes for PLWBC. How to promote and sustain healthy lifestyle behaviours in cancer populations is not well understood. A single, overarching summary of evidence from published systematic reviews of lifestyle interventions which compares and contrasts findings can provide policy and practice professionals with the evidence needed for more effective decision making. This overview of systematic reviews provides a synthesis of evidence on the effectiveness and cost-effectiveness of interventions aimed at altering lifestyle behaviours for improving outcomes for people living with and beyond cancer

Formal Verification of a Rover Anti-collision System

In this paper, we integrate inductive proof, bounded model checking, test case generation and equivalence proof techniques to verify an embedded system. This approach is implemented using Systerel Smart Solver (S3) toolset. It is applied to verify properties at system, software, and code levels. The verification process is illustrated on an anti-collision system (ARP for Automatic Rover Protection) implemented on-board a rover. Focus is placed on the verification of safety and functional properties and the proof of equivalence between the design model and the generated code

Social technologies for online learning: theoretical and contextual issues

Three exemplars are presented of social technologies deployed in educational contexts: wikis; a photo-sharing environment; and a social bookmarking tool. Students were found to engage with the technologies selectively, sometimes rejecting them, in the light of their prior conceptions of education. Some students (a minority in all the studies) were unsympathetic to the educational philosophy underpinning the technology’s adoption. The paper demonstrates, through an examination of in-context use, the importance of socio-cultural factors in relation to education, and the non-deterministic nature of educational technology. The academic study of technology has increasingly called into question the deterministic views which are so pervasive in popular discourse and among policy makers. Instead, socio-cultural factors play a crucial role in shaping and defining technology and educational technology is no exception, as the examples in the paper show. The paper concludes by drawing out some implications of the examples for the use of social technologies in education

The effectiveness and cost-effectiveness of a complex community sport intervention to increase physical activity: An interrupted time series design

© Author(s) (or their employer(s)) 2018. Objectives: An effectiveness and cost-effectiveness analyses of two-staged community sports interventions, taster sports sessions compared with portfolio of community sport sessions. Design: Quasi-experiment using an interrupted time series design. Setting: Community sports projects delivered by eight lead partners in London Borough of Hounslow, United Kingdom Participants: Inactive people aged 14 plus years (n=246) were recruited between May 2013–February 2014. Interventions: Community sports interventions delivered in two stages, 6-week programme of taster sport sessions (Stage1) and 6-week programme of portfolio of community sporting sessions delivered by trained coaches (Stage2). Primary and secondary outcome measures: Change in days with ≥30 min of self-reported vigorous intensity physical activity (PA), moderate intensity PA, walking, sport, subjective wellbeing, and EQ5D5L quality-adjusted life-years (QALYs) Methods: Interrupted time series analysis evaluated the effectiveness of the two sports programmes. Cost-effectiveness analysis compares Stage 2 with Stage 1 from a provider’s perspective, reporting outcomes of incremental cost per Quality Adjusted Life Year (QALY) (2015/16 price year). Uncertainty was assessed using deterministic and probabilistic sensitivity analyses. Results: Compared with Stage1, counterfactual change at 21 days in PA was lower for vigorous (log odds: -0.52; 95% CI -1, -0.03), moderate PA (-0.50; CI 0.94, -0.05) and sport (-0.56; CI -1.02, -0.10). Stage 2 increased walking (0.28; CI 0.3, 0.52). Effect overtime was similar. Counterfactual change at 21 days in wellbeing was positive particularly for ‘happiness’ (0.29; CI 0.06, 0.51). Stage2 was more expensive (£101 per participant) but increased QALYs (0.001; CI -0.034, 0.036). Cost per QALY for Stage2 was £50000 and has 29% chance of being cost effective (£30000 threshold). Conclusion: Community based sport interventions could increase PA among inactive people. Less intensive sports sessions may be more effective and cost-effective

Cost-effectiveness of offering an area-level financial incentive on breast feeding: a within-cluster randomised controlled trial analysis

Objective To provide the first estimate of the cost-effectiveness of financial incentive for breastfeeding intervention compared with usual care. Design Within-cluster (‘ward’-level) randomised controlled trial cost-effectiveness analysis (trial registration number ISRCTN44898617). Setting Five local authority districts in the North of England. Participants 5398 mother-infant dyads (intervention arm), 4612 mother-infant dyads (control arm). Interventions Offering a financial incentive (over a 6-month period) on breast feeding to women living in areas with low breastfeeding prevalence (<40% at 6–8 weeks). Main outcome measures Babies breast fed (receiving breastmilk) at 6–8 weeks, and cost per additional baby breast fed. Methods Costs were compared with differences in area-level data on babies’ breast fed in order to estimate a cost per additional baby breast fed and the quality-adjusted life year (QALY) gains required over the lifetime of babies to justify intervention cost. Results In the trial, the total cost of providing the intervention in 46 wards was £462 600, with an average cost per ward of £9989 and per baby of £91. At follow-up, area-level breastfeeding prevalence at 6–8 weeks was 31.7% (95% CI 29.4 to 34.0) in control areas and 37.9% (95% CI 35.0 to 40.8) in intervention areas. The adjusted difference between intervention and control was 5.7 percentage points (95% CI 2.7 to 8.6; p<0.001), resulting in 10 (95% CI 6 to 14) more additional babies breast fed in the intervention wards (39 vs 29). The cost per additional baby breast fed at 6–8 weeks was £974. At a cost per QALY threshold of £20 000 (recommended in England), an additional breastfed baby would need to show a QALY gain of 0.05 over their lifetime to justify the intervention cost. If decision makers are willing to pay £974 (or more) per additional baby breast fed at a QALY gain of 0.05, then this intervention could be cost-effective. Results were robust to sensitivity analyses. Conclusion This study provides information to help inform public health guidance on breast feeding. To make the economic case unequivocal, evidence on the varied and long-term health benefits of breast feeding to both the baby and mother and the effectiveness of financial incentives for breastfeeding beyond 6–8 weeks is require

PACE-UP (Pedometer and consultation evaluation--UP)--a pedometer-based walking intervention with and without practice nurse support in primary care patients aged 45-75 years: study protocol for a randomised controlled trial.

BACKGROUND: Most adults do not achieve the 150 minutes weekly of at least moderate intensity activity recommended for health. Adults' most common physical activity (PA) is walking, light intensity if strolling, moderate if brisker. Pedometers can increase walking; however, most trials have been short-term, have combined pedometer and support effects, and have not reported PA intensity. This trial will investigate whether pedometers, with or without nurse support, can help less active 45-75 year olds to increase their PA over 12 months. METHODS/DESIGN: DESIGN: Primary care-based 3-arm randomized controlled trial with 12-month follow-up and health economic and qualitative evaluations. PARTICIPANTS: Less active 45-75 year olds (n = 993) will be recruited by post from six South West London general practices, maximum of two per household and households randomised into three groups. Step-count and time spent at different PA intensities will be assessed for 7 days at baseline, 3 and 12 months by accelerometer. Questionnaires and anthropometric assessments will be completed. INTERVENTION: The pedometer-alone group will be posted a pedometer (Yamax Digi-Walker SW-200), handbook and diary detailing a 12-week pedometer-based walking programme, using targets from their baseline assessment. The pedometer-plus-support group will additionally receive three practice nurse PA consultations. The handbook, diary and consultations include behaviour change techniques (e.g., self-monitoring, goal-setting, relapse prevention planning). The control group will receive usual care. OUTCOMES: Changes in average daily step-count (primary outcome), time spent sedentary and in at least moderate intensity PA weekly at 12 months, measured by accelerometry. Other outcomes include change in body mass index, body fat, self-reported PA, quality of life, mood and adverse events. Cost-effectiveness will be assessed by the incremental cost of the intervention to the National Health Service and incremental cost per change in step-count and per quality adjusted life year. Qualitative evaluations will explore reasons for trial non-participation and the interventions' acceptability. DISCUSSION: The PACE-UP trial will determine the effectiveness and cost-effectiveness of a pedometer-based walking intervention delivered by post or practice nurse to less active primary care patients aged 45-75 years old. Approaches to minimise bias and challenges anticipated in delivery will be discussed