448 research outputs found

    The structure of aliphatic amine adducts of uranyl acetylacetonate. II. Dioxobis(2,4-pentanedionato)mono (2-N,N-dimethylaminopentan-4-one)uranium(VI)

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    Introduction: In a previous analysis of a compound of this type, we have established that the adduct molecule is bonded through O and that the geometry about U is pentagonal bipyramidal (Haigh, Nassimbeni, Pauptit, Rodgers & Sheldrick, 1976). We have carried out the present analysis to study the conformational effects on the ligand brought about by substitution at N

    The structure of aliphatic amine adducts of uranyl acetylacetonate. IV. Dioxobis(2,4-pentanedionato) mono(2-aminopentan-4-one)uranium(VI)

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    Introduction: We have shown in three earlier determinations of aliphatic amine adducts of U02(AA)2 (part I: Haigh, Nassimbeni, Pauptit, Rodgers & Sheldrick, 1976; part II: Nassimbeni, Orpen, Pauptit, Rodgers & Haigh, 1977; part III: Rodgers, Nassimbeni & Haigh, 1977) that the conformation of the adduct is dependent on its ability to form hydrogen bonds. The present compound has two H atoms available for hydrogen bonding and may be regarded as the parent of the series

    Expansion of the ligand knowledge base for chelating P,P-donor ligands (LKB-PP)

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    [Image: see text] We have expanded the ligand knowledge base for bidentate P,P- and P,N-donor ligands (LKB-PP, Organometallics2008, 27, 1372–1383) by 208 ligands and introduced an additional steric descriptor (nHe(8)). This expanded knowledge base now captures information on 334 bidentate ligands and has been processed with principal component analysis (PCA) of the descriptors to produce a detailed map of bidentate ligand space, which better captures ligand variation and has been used for the analysis of ligand properties

    Bis(1,3-dibenzyl­imidazolium) μ-oxido-bis­[trichloridoferrate(III)]

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    In the title compound (C17H17N2)2[Fe2Cl6O], obtained from the solid-state reaction of FeCl2 and N,N′-dibenzyl­imidazolium chloride, the complex anion has approximate D 3d symmetry with crystallographically imposed inversion symmetry coincident with the bridging μ-O atom. The stereochemistry about each FeCl3O centre is distorted tetra­hedral [Fe—Cl = 2.2176 (5)–2.2427 (5) Å and Fe—O = 1.7545 (2) Å]. The Cl atoms are involved in weak anion–cation C—H⋯Cl inter­actions, giving a network structure

    Vulnerability analysis of satellite-based synchronized smart grids monitoring systems

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    The large-scale deployment of wide-area monitoring systems could play a strategic role in supporting the evolution of traditional power systems toward smarter and self-healing grids. The correct operation of these synchronized monitoring systems requires a common and accurate timing reference usually provided by a satellite-based global positioning system. Although these satellites signals provide timing accuracy that easily exceeds the needs of the power industry, they are extremely vulnerable to radio frequency interference. Consequently, a comprehensive analysis aimed at identifying their potential vulnerabilities is of paramount importance for correct and safe wide-area monitoring system operation. Armed with such a vision, this article presents and discusses the results of an experimental analysis aimed at characterizing the vulnerability of global positioning system based wide-area monitoring systems to external interferences. The article outlines the potential strategies that could be adopted to protect global positioning system receivers from external cyber-attacks and proposes decentralized defense strategies based on self-organizing sensor networks aimed at assuring correct time synchronization in the presence of external attacks

    Orientalising deafness: race and disability in imperial Britain

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    This article explores the conflations and connections that postcolonial and disability scholars have drawn between ‘race’, ‘colonialism’ and ‘disability’ from a historical perspective. By looking at the connections drawn between ‘race’ and ‘disability’ in the context of nineteenth-century imperial Britain, I hope to probe beyond them to examine the origins and implications of their interplay. I do so by focusing on ideas about deafness, an impairment radically reconfigured in the colonial period, and inflected with concerns about degeneration, belonging, heredity and difference. Disability, I argue, not only operated as an additional ‘category of difference’ alongside ‘race’ as a way of categorising and subjugating the various ‘others’ of Empire, but intersected with it. The ‘colonisation’ of disabled people in Britain and the ‘racial other’ by the British were not simply simultaneous processes or even analogous ones, but were part and parcel of the same cultural and discursive system. The colonising context of the nineteenth century, a period when British political, economic and cultural expansion over areas of South Asia, Australasia and Africa increased markedly, structured the way in which all forms of difference were recognised and expressed, including the difference of deafness. So too did the shifts in the raced and gendered thinking that accompanied it, as new forms of knowledge were developed to justify, explain and contest Britain's global position and new languages were developed through which to articulate otherness. Such developments reconfigured the meaning of disability. Disability was, in effect, ‘orientalised’. ‘Race’ I argue was formative in shaping what we have come to understand as ‘disability’ and vice versa; they were related fantasies of difference

    An exploratory analysis of planning characteristics in Australian visitor attractions

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    This paper provides an exploratory analysis of the planning practices of 408 Australian attraction operators. The results indicate that attraction managers can be divided into four categories: those that do not engage in any formal planning, those that adopt a short-term planning approach, those that develop long-term plans, and those that use both short-term and long-term planning approaches. An evaluation of the sophistication of attraction planning showed a bipolar distribution. Attraction managers favored a planning horizon of three or five years, and were inclined to involve their employees in the planning process. Managers relied strongly on their own research and tourism industry intelligence when formulating business plans. The content of plans tended to focus on operational activities, financial planning and marketing. The study provides a benchmark for the comparison of attraction planning efforts in various contexts. © 2006 Asia Pacific Tourism Association
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