Palaeontology, the biogeohistory of Victoria

The broad-scale distribution of fossils within Victoria is controlled by general global patterns in the biological evolution of life on Earth, the local development and environmental evolution of habitats, and the occurrence of geological processes conducive to the preservation of fossil floras and faunas. Early Palaeozoic fossils are mostly marine in origin because of the predominance of marine sedimentary rocks in Victoria and because life on land was not significant during most of this time interval. Middle Palaeozoic sequences have both terrestrial and marine fossil records. Within Victoria, marine rocks are only very minor components of strata deposited during the late Palaeozoic, so that few marine fossils are known from this time period. A similar situation existed during most of the Mesozoic except towards the end of this era when marine conditions began to prevail in the Bass Strait region. During long intervals in the Cainozoic, large areas of Victoria were flooded by shallow-marine seas, particularly in the southern basins of Bass Strait, as well as in the northwest of the State (Murray Basin). Cainozoic sediments contain an extraordinary range of animal and plant fossils. During the Quaternary, the landscape of Victoria became, and continues to be, dominated by continental environments including, at times, extensive freshwater lake systems. Fossil floras and faunas from sediments deposited in these lake systems and from other continental sediments, as well as from Quaternary sediments deposited in marginal marine environments, collectively record a history of rapid fluctuations in climate and sea level.<br /

Performance evaluation of reverse osmosis (RO) pre-treatment technologies for in-land brackish water treatment

Integration of renewable energy with desalination technologies has emerged as an attractive solution to augment fresh water supply sustainably. Fouling and scaling are still considered as limiting factors in membrane desalination processes. For brackish water treatment, pre-treatment of reverse osmosis (RO) feed water is a key step in designing RO plants avoiding membrane fouling. This study aims to compare at pilot scale the rejection efficiency of RO membranes with multiple pre-treatment options at different water recoveries (30, 35, 40, 45 and 50%) and TDS concentrations (3500, 4000, and 4500mg/L). Synthetic brackish water was prepared and performance evaluation were carried out using brackish water reverse osmosis (BWRO) membranes (Filmtec LC-LE-4040 and Hydranautics CPA5-LD-4040) preceded by 5 and 1μm cartridge filters, 0.02μm ultra-filtration (UF) membrane, and forward osmosis (FO) membrane using 0.25M NaCl and MgCl2 as draw solutions (DS). It was revealed that FO membrane with 0.25M MgCl2 used as a draw solution (DS) and Ultra-filtration (UF) membrane followed by Filmtec membrane gave overall 98% rejection but UF facing high fouling potential due to high applied pressure. Use of 5 and 1μm cartridge filter prior to Filmtec membrane also showed effective results with 95% salt rejection

Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events

We present a measurement of the W+W- production cross section using 184/pb of ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W+W- -> l+l-vvbar, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0+2.2-0.8 events. The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-) = 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the Standard Model expectation.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review Letter

Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Final report, September 18, 1978-December 31, 1979

The research has sought the following: to identify and characterize the basic photovoltaic mechanisms that govern the conversion efficiency of polycrystalline thin-film solar cells; to experimentally determine the electronic parameters related to these photovoltaic mechanisms; and to relate these mechanisms and parameters to the conversion efficiency through theoretical physical models developed for engineering design. These objectives are all intimately related. The emphasis of the work has been on polysilicon, although it is building a foundation of understanding useful for similar research in the future on other thin-film materials. Progress is reported. (WHK

Physical models of thin film polycrystalline solar cells based on measured grain-boundary and electronic-parameter properties. Quarterly report

Solar cells fabricated on polycrystalline silicon, either bulk or thin-film, can potentially be cost-effective when used in terrestrial photovoltaic energy-conversion systems. To achieve this goal, the polysilicon cell efficiency must be increased considerably from its present values. A severe limitation to the cell efficiency is due to the grain boundaries and their influence on carrier recombination. To remove this limitation, an understanding of the fundamental physics underlying the effects of the grain boundaries on cell performance is helpful. This fundamental physics is discussed, and models are developed for recombination currents in polysilicon pn-junction solar cells. Several analytic approximations, suggested by physical insight, are used and checked ultimately for self-consistency with the results of the analysis. The models are defined such that their parameters can be related directly to measurements, and the models are hence useful in interpreting experimental results. They also can be used to study, in a systematic way, cell-design modifications to improve the efficiency, e.g., grain-boundary passivation techniques

Structural, electrical, and optical properties of diamondlike carbon films deposited by dc magnetron sputtering

The electrical and optical properties of diamondlike carbon films deposited by direct current magnetron sputtering on Si substrates at room temperature have been measured as a function of the ion energy (Eion) and ion-to-carbon flux (Jion/JC). The results show that, in the ranges of 5 eV⩽Eion⩽85 eV and 1.1⩽Jion/JC⩽6.8, the presence of defective graphite formed by subplanted C and Ar atoms, voids, and the surface roughness, are the dominant influences on the resistivity and optical absorption. The electrical and optical properties of diamondlike carbon films deposited by direct current magnetron sputtering on Si substrates at room temperature have been measured as a function of the ion energy (Eion) \u3e(Eion)(Eion) and ion-to-carbon flux (Jion/JC). \u3e(Jion/JC).(Jion/JC). The results show that, in the ranges of 5 eV⩽Eion⩽85 eV \u3e5 eV⩽Eion⩽85 eV5 eV⩽Eion⩽85 eV and 1.1⩽Jion/JC⩽6.8, \u3e1.1⩽Jion/JC⩽6.8,1.1⩽Jion/JC⩽6.8, the presence of defective graphite formed by subplanted C and Ar atoms, voids, and the surface roughness, are the dominant influences on the resistivity and optical absorption. REFERENCE