A comparison has been made of plasma-catalysis with thermal-catalysis and plasma alone for the removal of low concentrations of propane and propene from synthetic air using a one-stage, catalyst-in discharge configuration. In all cases, plasma-catalysis produces better hydrocarbon destructions (*40%) than thermal catalysis at low temperatures. At higher temperatures, little difference is observed between plasma-catalytic and thermal-catalytic operation. Plasma operation by itself had a similar effectiveness to plasma-catalysis at low temperatures but was significantly lower (up to 50%) as the temperature was raised. By examining the form of the temperature dependence for the plasma-catalytic destruction processes, it is possible to phenomenologically distinguish two contributions to the destruction; one that is specifically plasma-induced and another (at higher temperatures) in which both plasma and thermal activation have similar mechanisms.

Purpose -In the context of changes in the priority given to ensuring that health care is evidence-based, and that service quality should be maximised, there is a new emphasis on quality improvement programmes in the UK National Health Service (NHS). It is not clear how far these programmes can be categorised using the paradigms of research and audit. Making a distinction between what constitutes audit, quality improvement and research is important in the context of enhanced clinical and research governance requirements and in an environment of both sensitivity in relation to the ethics of research and concern about the efficacy of ethics committees. This study aims to address this issue. Design/methodology/approach -This article reviews the literature on how quality improvement differs from audit and research. It considers different ways of considering ethics in research and questions how far one can rely on professional judgement as an alternative to formal ethics committee procedures. The factors that characterise different sorts of activity are reworked to enable a template to be devised. The template, presented in the form of a flow-chart, enables health care workers to better categorise a variety of activities and highlights the necessary procedural requirements that follow. Findings -Key factors are identified in the existing literature that help differentiate between quality improvement, audit and research. These factors range from intent in undertaking the activity, through sample/site selection, choice of methodology, analysis, patterns and speed of dissemination. Originality/value -If quality improvement is to continue to be a central theme in the NHS agenda, it is important that both the Central Office for Ethical Review and NHS organisations review the categorisation system to include quality improvement in their clinical effectiveness structures.

A dielectric packed‐bed plasma reactor was used for the destruction of propane in air and was successfully created and maintained at higher than atmospheric pressure (3 bar). The effects of pressure, REF and SED on propane removal and NOx production are discussed. An increase in SED enhances propane destruction and increases NOx production. Increasing the pressure to 3 bar produces a more efficient removal process with an energy of 877 and 600 eV per molecule at 1 and 3 bar, respectively. The pressure increase also altered the ratio of NO2 to NO produced from ≈1 to >3, showing that substantially more NO2 than NO is produced in a 3 bar air discharge. magnified image

Surface discharge plasma reactors (SDRs) have been shown to be effective in removing a wide range of pollutants. In this study, the effectiveness of a SDR for the removal of propane and propene from an atmospheric pressure air stream was investigated. For an input energy of 100 J L-1, the conversions were found to be 16% and 68% for propane and propene, respectively. The total carbon recovery was found to increase with increasing specific input energy (SIE) for both hydrocarbons. FTIR analysis showed that CO and CO2 are the major end-products, and GC-MS identified formic acid as a significant byproduct. The effect of initial propane concentration was also investigated. The reaction chemistry involved in the oxidative plasma conversion of propane and propene is discussed.