170,885 research outputs found
The heliotrope mazurka [music] /
No full textFor piano.; Cover title.; "Dedicated to Miss C. Joseph" -- Caption.; Lithographer: Allan & Wigley.; Cover illustration of Sydney from northshore by E. Thomas.; Published in: Australian music.; Also available online http://nla.gov.au/nla.mus-an5396834
Mechanisms for accumulation and migration of technetium-99 in saltmarsh sediments
No full textThis thesis describes the development of analytical methods for both the bulk determination of 99Tc, and determination of 99Tc in sequential extracts from sediments. These methods have been used to collect data, which, along with trace and major element data have been used to interpret the mechanisms for 99Tc input, migration and accumulation in saltmarshes. The inventory of 99Tc stored in the Thornflatt Saltmarsh, Esk Estuary has also been determined. The routine determination of 99Tc in bulk samples uses 99mTc as a yield monitor. Samples are ignited stepwise to 550°C and the 99Tc is extracted using 8M nitric acid. Many contaminants are precipitated with Fe(OH)3 and the Tc in the supernant is pre-concentrated and further purified using anion-exchange chromatography. Final separation of Tc from Ru is achieved by extraction of Tc into 5% TnOA in xylene from 2M sulphuric acid. The yield is determined by γ-spectrometric analysis of 99mTc. Determination of 99Tc is made by liquid scintillation counting. Typical recoveries are in the order of 70-95% and the method has a detection limit of 1.7 Bq/kg for a sample size of 10g. Determination of Tc in sequential extracts uses operationally defined procedures to extract: exchangeable Tc, reducible Tc and oxidisable Tc. An initial water wash is used to extract any occluded Tc and a final leach in 8 M nitric acid is used to dissolve any residual Tc. The isolation of 99Tc uses TEVA resin for Extracts 1-4 and the decontamination procedure developed for bulk analysis for Extract 5. 99mTc was used as a yield monitor, and determination of 99Tc is by liquid scintillation counting. Limits of detection were dependent on the amount of 99mTc tracer used but were found to be as low as 2.4 Bq/kg for a sample size of 2g. A study was made of the mechanisms responsible for the accumulation and migration of Tc in estuarine sediments using sediments collected from saltmarshes at Thornflatt, Carlaverock and the Ribble Estuary. 99Tc was present at determinable activities in all the sediment cores taken from these sites. Good correlations between Tc and CaO as well as CO3 concentrations and poor correlation between Tc and radionuclides adsorbed to inorganic detritus infer a direct input of 99Tc to marsh sediments. Determination of 99Tc in biota living on the marsh also showed that this was not a significant pathway for input of Tc to the sediments. Sequential extraction data imply sorption to an organic fraction of the sediment. Stable element and sequential extraction data indicates that Tc is readily oxidised and remobilised before reprecipitation where redox conditions are favourable. Data indicate a reduction potential between those of the MnIV to MnII reaction and the FeIII to FeII reaction is necessary for re-accumulation to occur, as suggested by published thermodynamic data. Data collected from reducing sediments imply that similar mechanisms are responsible for the accumulation of Mn (e.g. reduction by sulphate reducing bacteria) and the accumulation of Tc. The inventory of 99Tc held within the Thornflatt saltmarsh is proportionally less than that of 137Cs or 241Am when compared to discharges from Sellafield. However a higher proportion of 99Tc is transferred from Seliafield and incorporated into saltmarsh sediments than is suggested by previously published standard distribution coefficient data. Saltmarsh sediments are therefore a more important sink of 99Tc than extrapolations made from inventories of other radionuclides would suggest
The Oneida polka [music] /
No full textFor piano.; Cover title.; Engraved.; "Dedicated to the G & ARM Company & to the Commander & Officers of the S.S. Onrieda".; "Played by Winterbottom's unrivalled band"--Caption.; Cover illustration: SS Oneida / by E. Thomas.; Lithographer: Allan & Wigley.; Published in: Australian music.; Publication date from G. Skinner (2011), 'Toward a general history of Australian musical composition: first national music, 1788-c.1860', Sydney Conservatorium of Music, p. 525 http://trove.nla.gov.au/work/81022028; Also available online http://nla.gov.au/nla.mus-an5397125
Molly Asthore valse [music] /
No full textFor piano.; Cover title.; "Founded on M. Lavenu's favourite ballads. Composed expressly for Her Majesty's birthday ball held at Governemnt House, Sydney, May 25th 1858, and most respectfully inscribed to Lady Denison".; Cover illustration of young woman.; Lithographer: Allan & Wigley.; Publication date from G. Skinner (2011), 'Toward a general history of Australian musical composition: first national music, 1788-c.1860', Sydney Conservatorium of Music, p. 538 http://trove.nla.gov.au/work/81022028; Published in: Australian music.; Also available online http://nla.gov.au/nla.mus-an5397123
Plan of Dunblane, part of the Camperdown estate [cartographic material] /
No full textInset: Locality sketch.; Map 321 from Ferguson Collection.; Sales plan of estate in Camperdown, N.S.W.; Also available in an electronic version via the Internet at: http://nla.gov.au/nla.map-f321
The Australian Masonic waltzes [music] /
No full textCover title.; "Composed and dedicated with fraternal regard to Sir Saml. Osbourne Gibbes, Bart ...".; "In this waltz are introduced the entered Apprentice song and the very popular airs "While we have missed you" and "Ever of thee".; Cover illustration by E. Thomas.; Lithographer: Allan & Wigley.; Published in: Australian music.; Publication date from G. Skinner (2011), 'Toward a general history of Australian musical composition: first national music, 1788-c.1860', Sydney Conservatorium of Music, p. 546 http://trove.nla.gov.au/work/81022028; Also available online http://nla.gov.au/nla.mus-an5397181. 1. Ever of thee -- 2. The enter'd apprentices song -- 3. Willie, we have missed you
Dangerous assumptions
No full textHow big is the energy challenge of climate change? The technological advances needed to stabilize carbon-dioxide emissions may be greater than we think, argue Roger Pielke Jr, Tom Wigley and Christopher Green.Roger Pielke, Tom Wigley & Christopher Gree
Burden of proof: a comprehensive review of the feasibility of 100% renewable-electricity systems
No full textAbstract not availableB.P. Heard, B.W. Brook, T.M.L. Wigley, C.J.A. Bradsha
Morphological and physiological interactions of NG2-glia with astrocytes and neurons
No full textModels of central nervous system (CNS) function have historically been based on neurons and their synaptic contacts - the neuronal doctrine. This doctrine envisages glia as passive supportive cells. However, electrophysiological and imaging studies in brain slices show us that astrocytes, the most numerous cells in the brain, express a wide range of neurotransmitter receptors that are activated in response to synaptic activity. Furthermore, astrocytes communicate via calcium signals that are propagated over long distances by the release of 'gliotransmitters', the most abundant being adenosine triphosphate (ATP). This has led to the concept of the neuron-astroglial functional unit as the substrate of integration in the CNS. Recently, a novel glial cell type has been characterized by expression of the proteoglycan NG2. These NG2-glia receive presynaptic input from neurons and responds to neurotransmitters released at synapses. Now, studies on transgenic mice in which fluorescent proteins are specifically expressed by subclasses of glia are helping to address the question of where NG2-glia fit in the neuron-astroglial model of integrated brain function. NG2-glia, as well as astrocytes, have been shown to respond to neuronal and astroglial signals by raised intracellular calcium, which is a potential communications mechanism by which NG2-glia may be active partners in neuron-glial circuits. Moreover, a current concept of NG2-glia considers them to be 'neural stem cells' and an exciting prospect is that neuron-glial signalling may regulate the differentiation capacity of NG2-glia and their response to injury.</p
- …
