414 research outputs found

    Atmospheric reactions of ethers and ketones

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    The atmospheric lifetimes of a series of ethers and ketones was established, with respect to reaction with O H radicals and Cl atoms, using a relative rate smog chamber technique. Reactivity of these compounds was affected by , their C - H bond dissociation energies, the oxygen atom in their structure, steric effects, and polarity contributions. From the rate constant data calculated in this work it was concluded that the tropospheric lifetimes of these compounds is primarily determined by their reactivity with O H radicals. Only four of the compounds analysed (2- chloro,1,1 ,1-trifluoro ethyl ethyl ether, Isoflurane, enflurane and acetone) had sufficiently long tropospheric lifetimes which will allow transportation of these species to the stratosphere. Three of these compounds were chlorinated ethers. These species may release their chlorine atoms in the stratosphere , ultimately resulting In ozone depletion . Release figures for the two halogenated an aesthetic ethers, isoflurane and enflurane , were calculated in our laboratory and combined with atmospheric lifetime data to establish the possible contribution of the anaesthetics to ozone depletion. It was estimated that only a fraction of the released species will be effective in causing ozone depletion. To establish the ulitlmate atmospheric fate of the anaesthetics , stratospheric photooxidation reaction mechanisms were investigated for these species. Result data indicated that the anaesthetics will undergo reaction processes initiated by chlorine atoms produced from the photodecomposition of the parent species. These chlorine-sensitised photooxidation reaction mechanisms ultimately lead to the formation of CF 20 and C02 , both greenhouse gases. Although the anaesthetics isoflurane and enflurane are released to the troposphere, their effect on stratospheric ozone and on world climate was estimated to be minimal compared with other CFCs. This work serves as a quick guide to the type of reaction processes which are important in environmental assessment of volatile anthropogenic species and also illustrates the significance of secondary factors such as emission figures, reaction products, etc., in atmospheric quality assessment

    Exploring natural resources for dealing with waste: The Estuarine Research Group at WIT

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    The Estuarine Research Group (ERG) has a range of scientific expertise from molecular biology and bioremediation to inorganic chemistry and biological separations. Development of this research team was facilitated through funding under the Technological Sector Research Strand III (Core research strengths enhancement 2000-2006) initiative. Phase I projects of the research team are focused on novel, fundamental investigations into the chemical and biological mechanisms involved in heavy metal sequestration and binding to a range of seaweeds (Phaeophyceae, Rhodophyceae, and Chlorophyceae) commonly found in the South-East of Ireland. Such research, although fundamental in nature, has positive economic implications for society through the potential development of our natural resources as bioremediation products for metal-laden wastewater streams. A number of parallel research strands involving genetic, bioremediation, ecological and chemical studies are currently ongoing in the group. The combined output from these research elements is aimed at gaining a better understanding of the dynamics of metal uptake by seaweed species

    The case for research in game engine architecture.

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    Exploring the Origins of EU Peacebuilding in Northern Ireland through the Role of John Hume and the European Parliament

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    This article explores the origins of the European Union (EU) peacebuilding approach in Northern Ireland through the role of the long-serving MEP and Nobel Laureate, John Hume. It gives particular emphasis to the part played by the European Parliament (EP) in this endeavour, which has been neglected in existing studies of the EU influence on Northern Ireland. The article shows how Hume helped to create better understanding, interest and ultimately engagement by the EU to support peacebuilding efforts in Northern Ireland. Local political shifts would prove decisive in creating the peace process that emerged in the region in the 1990s, but the article argues that Hume's efforts, stretching as far back as the 1970s, both encouraged these shifts and then provided the basis for much greater EU engagement in support of the peace process. This deepens our understanding of the EU role in aiding political change in Northern Ireland
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