7,720 research outputs found

    Energy storage in the UK electrical network : estimation of the scale and review of technology options

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    This paper aims to clarify the difference between stores of energy in the form of non-rechargeable stores of energy such as fossil-fuels, and the storage of electricity by devices that are rechargeable. The existing scale of these two distinct types of storage is considered in the UK context, followed by a review of rechargeable technology options. The storage is found to be overwhelmingly contained within the fossil-fuel stores of conventional generators, but their scale is thought to be determined by the risks associated with long supply chains and price variability. The paper also aims to add to the debate regarding the need to have more flexible supply and demand available within the UK electrical network in order to balance the expected increase of wind derived generation. We conclude that the decarbonisation challenge facing the UK electricity sector should be seen not only as a supply and demand challenge but also as a storage challenge. (c) 2010 Elsevier Ltd. All rights reserved

    Grid-connected renewables, storage and the UK electricity market

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    This article is a critical counterpoint to an article by published by Swift-Hook in the journal of Renewable Energy entitled "Grid-connected intermittent renewables are the last to be stored". In contrast to Swift-Hook we found evidence that "grid-connected intermittent renewables" have been, and will continue to be stored when it suits the "UK market" to do so.  This article is important to policy makers as energy storage (through EV battery demand side management for example) may well have an important role to play in facilitating the integration of high wind penetrations

    Further notes on the typification of some species in Indigofera (Fabaceae)

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    The typification of the names of three non-endemic species of Indigofera in Australia is revisited. Firstly, the uncertain typification of an introduced species, I. hochstetteri Baker, is considered; a previous, imprecise lectotypification is recognised and a second step lectotype is designated. Secondly, an earlier error in the citation of the type of another introduced species, I. sessiliflora DC., is corrected and specific details of the holotype are provided. Thirdly, a lectotype is designated for I. seticulosa Harv., a synonym of the widespread native species, I. colutea (Burm.f.) Merr

    Additional species in the Indigofera haplophylla group (Fabaceae: Faboideae)

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    Two additional species in the Indigofera haplophylla are described. Indigofera brennanii Peter G. Wilson, is a recently discovered taxon that occurs on Groote Eylandt and in Limmen National Park on the adjacent mainland. Indigofera fimbriolata Peter G. Wilson is a geographically isolated species that occurs in Bulleringa National Park, Queensland; it was formerly included in I. rupicola. Although both taxa are found in national parks, their conservation status has not been assessed

    Progress towards resolution of the Indigofera monophylla complex (Fabaceae: Faboideae)

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    The application of the name Indigofera monophylla is clarified by reference to the type held in the Geneva herbarium and an revised description provided. The name has been widely applied to plants with rounded, unifoliolate leaves and some workers have suggested that there are multiple species within this broadly defined group. One of these has previously been given the phrase name Indigofera sp. Bungaroo Creek (S. van Leeuwen 4301) and this is formally named here as Indigofera rivularis Peter G. Wilson. Two additional species in this complex are also described: Indigofera deserticola Peter G. Wilson & Rowe, is a species of sandplains occurring within the Great Sandy Desert and Dampierland Bioregions, and Indigofera rotula Peter G. Wilson, which is a species with smaller leaves and flowers that occurs primarily in areas south of the Pilbara. A key to these species is provided

    Insights into antibody catalysis: Structure of an oxygenation catalyst at 1.9-Å resolution

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    The x-ray crystal structures of the sulfide oxidase antibody 28B4 and of antibody 28B4 complexed with hapten have been solved at 2.2-Å and 1.9-Å resolution, respectively. To our knowledge, these structures are the highest resolution catalytic antibody structures to date and provide insight into the molecular mechanism of this antibody-catalyzed monooxygenation reaction. Specifically, the data suggest that entropic restriction plays a fundamental role in catalysis through the precise alignment of the thioether substrate and oxidant. The antibody active site also stabilizes developing charge on both sulfur and periodate in the transition state via cation-pi and electrostatic interactions, respectively. In addition to demonstrating that the active site of antibody 28B4 does indeed reflect the mechanistic information programmed in the aminophosphonic acid hapten, these high-resolution structures provide a basis for enhancing turnover rates through mutagenesis and improved hapten design

    A new species of Indigofera (Fabaceae: Faboideae) from Central Australia

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    A new species, Indigofera centralis Peter G. Wilson & Rowe, is described from Central Australia, west of the Finke Gorge National Park in the Northern Territory; it resembles some other inland species (I. fractiflexa, I. gilesii, I. warburtonensis and I. helmsii) but differs most conspicuously by the relatively larger flowers

    Theoretical studies of the phase transition in the anisotropic 2-D square spin lattice

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    The phase transition occurring in a square 2-D spin lattice governed by an anisotropic Heisenberg Hamiltonian has been studied according to two recently proposed methods. The first one, the Dressed Cluster Method, provides excellent evaluations of the cohesive energy, the discontinuity of its derivative around the critical (isotropic) value of the anisotropy parameter confirms the first-order character of the phase transition. Nevertheless the method introduces two distinct reference functions (either N\'eel or XY) which may in principle force the discontinuity. The Real Space Renormalization Group with Effective Interactions does not reach the same numerical accuracy but it does not introduce a reference function and the phase transition appears qualitatively as due to the existence of two domains, with specific fixed points. The method confirms the dependence of the spin gap on the anisotropy parameter occurring in the Heisenberg-Ising domain
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