1,988 research outputs found
Metal fluorides, metal chlorides and halogenated metal oxides as Lewis acidic heterogeneous catalysts. Providing some context for nanostructured metal fluorides
Aspects of the chemistry of selected metal fluorides, which are pertinent to their real or potential use as Lewis acidic, heterogeneous catalysts, are reviewed. Particular attention is paid to β-aluminum trifluoride, aluminum chlorofluoride and aluminas γ and η, whose surfaces become partially fluorinated or chlorinated, through pre-treatment with halogenating reagents or during a catalytic reaction. In these cases, direct comparisons with nanostructured metal fluorides are possible. In the second part of the review, attention is directed to iron(III) and copper(II) metal chlorides, whose Lewis acidity and potential redox function have had important catalytic implications in large-scale chlorohydrocarbons chemistry. Recent work, which highlights the complexity of reactions that can occur in the presence of supported copper(II) chloride as an oxychlorination catalyst, is featured. Although direct comparisons with nanostructured fluorides are not currently possible, the work could be relevant to possible future catalytic developments in nanostructured materials
Politics, Culture, Urban Elites and Townscapes in Georgian England: A Case Study of Derby c.1720-1800
This study examines the political, cultural and social changes experienced by Derby in the eighteenth century and the effect these changes had on the built environment. Eighteenth-century Derby has been little analysed in national studies of urban history, partly due to a perceived lack of source material, especially the loss of the town’s corporation minute books which were destroyed by fire in 1841. This study corrects that oversight by examining the relationship between Derby’s urban renaissance and social and political culture in a national context. Utilising historical sources such as parish records, newspapers, and the minute books of improvement commissions, it builds a picture of eighteenth-century town government and social elites in political, cultural, and social contexts. This study argues that the Derbyshire rural nobility reduced their interest in the affairs of the county town during the second half of the eighteenth century concurrently as there was an increase in the political and financial power of a new elite made up of professionals, manufacturers, and urban gentry. Derby therefore did not experience a complete urban renaissance, characterised primarily by gentry cultural pursuits patronised chiefly by a visiting rural nobility but instead developed more associational middling sort cultural occupations created and supported by this new urban elite. Cultural activities such as assemblies, theatres and horse racing struggled whilst the middling sort cultures of clubs and societies thrived. This middling sort associational culture led primarily by ‘enlightenment men’ encouraged urban improvement often against considerable and numerous opposition, enlarging the town beyond its medieval footprint through enclosure of common land and paving and lighting. Politically, Derby has often been regarded as a Whig oligarchy controlled by the Dukes of Devonshire but this study shows that there were limits to this political influence. The elections of 1748 and 1775 in particular show how Derby burgesses had a large say in picking their MPs and as they mostly voted Tory, the Duke and his agents had to resort to heavy handed means to gain victory. These elections also demonstrate that the town’s politics were not always divided between Whigs and Tories but often between those willing to follow the will of the Cavendish family and their agents and those who did not. Pre-eminently, this study demonstrates that power in Derby’s eighteenth-century urban life was held by small groups of governors whether in the form of the corporation, the vestry, or improvement commissioners. This urban elite represented the economic elite of the borough and were primarily responsible for major changes in the town’s physical, cultural, and social character in the period. However, these changes were, at times, strongly contested and there was much friction between social and political groups meaning that the impact of the urban renaissance was limited
Assessment of the vendace population of Bassenthwaite Lake including observations on vendace spawning grounds. Progress Report for Period August 2007 to January 2008
Turning the Kaleidoscope: Telling Stories in Rhetorical Spaces
In this essay, I reflect on the work of Lorraine Code on Rhetorical Spaces and the work of Dorothy Smith on Institutional Ethnography to explore how stories are translated and seen as though looking through the different turns of a kaleidoscope. The stories I am referring to here are intake stories in human service agencies. The question is how do the front line human service workers translate the noise of everyday/night life of the client into the human service jargon/forms. I also explore the issues of how the front line worker with the intention of being professional. disembodies herself and the self of the client by dissociating from her life story during the translation process The ultimate purpose of my work is to develop a pedagogy for a human development program
High stakes testing policy issues in education: An analysis of litigation involving high stakes testing and the denial of diplomas
Harvest-induced disruptive selection increases variance in fitness-related traits
The form of Darwinian selection has important ecological and management implications. Negative effects of harvesting are often ascribed to size truncation (i.e. strictly directional selection against large individuals) and resultant decrease in trait variability, which depresses capacity to buffer environmental change, hinders evolutionary rebound and ultimately impairs population recovery. However, the exact form of harvest-induced selection is generally unknown and the effects of harvest on trait variability remain unexplored. Here we use unique data from the Windermere (UK) long-term ecological experiment to show in a top predator (pike, Esox lucius) that the fishery does not induce size truncation but disruptive (diversifying) selection, and does not decrease but rather increases variability in pike somatic growth rate and size at age. This result is supported by complementary modelling approaches removing the effects of catch selectivity, selection prior to the catch and environmental variation. Therefore, fishing most likely increased genetic variability for somatic growth in pike and presumably favoured an observed rapid evolutionary rebound after fishery relaxation. Inference about the mechanisms through which harvesting negatively affects population numbers and recovery should systematically be based on a measure of the exact form of selection. From a management perspective, disruptive harvesting necessitates combining a preservation of large individuals with moderate exploitation rates, and thus provides a comprehensive tool for sustainable exploitation of natural resources
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