1,634 research outputs found

    UK Large-scale Wind Power Programme from 1970 to 1990: the Carmarthen Bay experiments and the Musgrove Vertical-Axis Turbines

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    This article describes the development of the Musgrove Vertical Axis Wind Turbine (VAWT) concept, the UK ‘Carmarthen Bay’ wind turbine test programme, and UK government’s wind power programme to 1990. One of the most significant developments in the story of British wind power occurred during the 1970s, 1980s, and 1990s, with the development of the Musgrove vertical axis wind turbine and its inclusion within the UK Government’s wind turbine test programme. Evolving from a supervisor’s idea for an undergraduate project at Reading University, the Musgrove VAWT was once seen as an able competitor to the horizontal axis wind systems that were also being encouraged at the time by both the UK government and the Central Electricity Generating Board, the then nationalised electricity utility for England and Wales. During the 1980s and 1990s the most developed Musgrove VAWT system, along with three other commercial turbine designs was tested at Carmarthen Bay, South Wales as part of a national wind power test programme. From these developmental tests, operational data was collected and lessons learnt, which were incorporated into subsequent wind power operations.http://dx.doi.org/10.1260/03095240677860621

    Gendered play behaviours in autistic and non-autistic children: A population-based cohort study

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    Gender-typical play is observed throughout childhood for non-autistic children. However, there has been limited research into the gender typicality of autistic children’s play compared to that of non-autistic children. In a longitudinal population-based cohort, we compared gendered play behaviours in autistic and non-autistic children using standardised parent-report (30, 42 and 57 months) and child-report (8 years) data (N = 11,251). We observed no difference in gendered play behaviours between girls with or without autism at any time point. Autistic and non-autistic boys did not differ in the gender typicality of their play when aged 30 months, but the play of autistic boys appeared less masculine than that of non-autistic boys (β = −1.1, 95% confidence interval = −2.1 to −0.2; and β = −2.6, 95% confidence interval = −4.7 to −0.5) at 42 and 57 months. Autistic boys also self-reported less masculine play behaviours than non-autistic boys at 8 years of age (β = −3.4, 95% confidence interval = −6.6 to −0.2). We found that autistic boys’ play was less gender typical than that of non-autistic boys in middle and later childhood. Our findings highlight the importance of examining gendered play behaviours in a developmental context and have relevance for understanding the development of gender identity in autism. Lay abstract: Non-autistic children tend to show gendered patterns of play behaviours – boys are more likely to play with ‘masculine’ toys, and girls are more likely to play with ‘feminine’ toys. However, little is known about whether autistic children follow these patterns as well. We looked at the masculinity and femininity of autistic and non-autistic children’s play behaviours at multiple time points. Parents reported their children’s play behaviours at ages 30, 42 and 57 months, and children reported their own play behaviours at 8 years old. We found no difference between autistic and non-autistic girls, who both showed more feminine play behaviours as they got older. Autistic boys’ play behaviours were reported as less masculine than non-autistic boys at 42 and 57 months, and at 8 years old. We also found that non-autistic boys’ play tended to become more masculine as they got older, but this was not the case for autistic boys. Our findings suggest that differences in autistic and non-autistic boys’ play behaviours may develop at around 42 months old

    Chemical and mineralogical characterisation of illite-smectite: implications for episodic tectonism and associated fluid flow, central Australia

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    The Warburton-Cooper-Eromanga basins of central-eastern Australia contain a number of reactivated fracture-fault networks that relate to a complex and poorly understood thermal and tectonic evolution. Authigenic illite was sampled from two prominent features of the Warburton-Cooper basins: the Gidgealpa-Merrimelia-Innamincka Ridge, composed of anticlinal imbricate thrust fault blocks, and the synclinal Nappamerri Trough. These sample sets were investigated using a combination of clay mineralogical, trace element and stable isotope analyses to deduce the palaeofluid chemistry associated with past tectonothermal perturbations. The Nappamerri Trough hosts the highly radiogenic Big Lake Suite granite and part of one of Australia's larger on-shore oil and gas reserves. Calculated fluid stable isotope values from the trough, in conjunction with calculated palaeotemperatures, indicate an influx of evolved high-latitudinal meteoric waters under an extremely high geothermal gradient (~100°Ckm) and high water/rock ratios consistent with an extensional environment. Such high water/rock ratios resulted in intense alteration of the granite during which it underwent substantial enrichment in the heat-producing elements (HPE), particularly Th. This hydrothermal system is interpreted to result from continent-wide transmission of tensional stress originating from episodic rifting of the eastern Australian margin in the mid Cretaceous, as dated by Sm-Nd, Rb-Sr and Ar-Ar. The Gidgealpa-Merrimelia-Innamincka Ridge, by contrast, is marked by a lower, but still elevated, palaeogeothermal gradient (~42°Ckm) and calculated fluid isotopic values compatible with evolved basinal fluids of meteoric origin under low water/rock ratio conditions. Distinct trace element compositions of residue and leachate aliquots further indicate two periods of fluid flow with unique chemical compositions. In light of previous geochronology, these events are interpreted as westward extensions of widespread crustal tensional stress that affected much of central and eastern Queensland in the Carboniferous and Late Triassic. Integrated analyses of authigenic illite provide evidence for three periods of fluid flow and elevated thermal regime associated with regional tectonism during the Carboniferous, Late Triassic and Cretaceous. Our data further show that due to the extremely high geothermal gradient and water/rock ratios, Cretaceous fluid flow had profound effects on the surrounding geology, which may have formed/enhanced two of Australia's most significant energy resources

    Experimental mineral dissolution in Berea Sandstone reacted with CO2 or SO2 –CO2 in NaCl brine under CO2 sequestration conditions

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    A comparison of the geochemical changes induced in sandstone by either pure or impure CO2 at geological CO2 storage conditions was investigated. Samples of Berea Sandstone were batch reacted in 1% w/v NaCl brine saturated with pure CO2 or mixed SO2-CO2 gas for 360 h at 50 degrees C and 10 MPa. Geochemical analysis of incremental water samples showed increases in the concentrations of elements such as calcium, magnesium, iron, manganese, and silicon throughout experiments, likely being the products of carbonate and reactive silicate dissolution. Scanning electron microscope images taken of specific points of interest before and after batch reactions confirmed dissolution of carbonates, but showed no reaction for minerals such as K-feldspar. The magnitude of apparent mineral reaction was higher for the mixed gas SO2-CO2-brine experiment, with geochemical modelling also indicating greater dissolution of reactive silicates such as chlorite, and potential precipitation of amorphous silica. (C) 2014 Elsevier B.V. All rights reserved

    Approccio alla lingua italiana per allievi stranieri - ALIAS

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    Contiene, di P. E. Balboni, - "Approccio alla lingua italiana per allievi stranieri", pp. 55-71 - "Problemi interculturali nei rapporti con allievi stranieri e con le loro famiglie", pp. 73-90 - "La fomrazione dei docenti: i contenuti e gli strumenti di base", pp. 181-184

    Methane metabolism in the archaeal phylum Bathyarchaeota revealed by genome-centric metagenomics

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    Methanogenic and methanotrophic archaea play important roles in the global flux of methane. Culture-independent approaches are providing deeper insight into the diversity and evolution of methane-metabolizing microorganisms, but, until now, no compelling evidence has existed for methane metabolism in archaea outside the phylum Euryarchaeota. We performed metagenomic sequencing of a deep aquifer, recovering two near-complete genomes belonging to the archaeal phylum Bathyarchaeota (formerly known as the Miscellaneous Crenarchaeotal Group). These genomes contain divergent homologs of the genes necessary for methane metabolism, including those that encode the methyl–coenzyme M reductase (MCR) complex. Additional non-euryarchaeotal MCR-encoding genes identified in a range of environments suggest that unrecognized archaeal lineages may also contribute to global methane cycling. These findings indicate that methane metabolism arose before the last common ancestor of the Euryarchaeota and Bathyarchaeota

    Optically induced coherent intra-band dynamics in disordered semiconductors

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    On the basis of a tight-binding model for a strongly disordered semiconductor with correlated conduction- and valence band disorder a new coherent dynamical intra-band effect is analyzed. For systems that are excited by two, specially designed ultrashort light-pulse sequences delayed by tau relatively to each other echo-like phenomena are predicted to occur. In addition to the inter-band photon echo which shows up at exactly t=2*tau relative to the first pulse, the system responds with two spontaneous intra-band current pulses preceding and following the appearance of the photon echo. The temporal splitting depends on the electron-hole mass ratio. Calculating the population relaxation rate due to Coulomb scattering, it is concluded that the predicted new dynamical effect should be experimentally observable in an interacting and strongly disordered system, such as the Quantum-Coulomb-Glass.Comment: to be published in Physical Review B15 February 200

    Evidence of Electromagnetic Absorption by Collective Modes in the Heavy Fermion Superconductor UBe13

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    We present results of a microwave surface impedance study of the heavy fermion superconductor UBe13. We clearly observe an absorption peak whose frequency- and temperature-dependence scales with the BCS gap function. Resonant absorption into a collective mode, with energy approximately proportional to the superconducting gap, is proposed as a possible explantation
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