1,264 research outputs found

    Nitrogen removal and ammonia-oxidising bacteria in a vertical flow constructed wetland treating inorganic wastewater

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    Nitrogen removal performance and the ammonia-oxidising bacterial (AOB) community were assessed in the batch loaded 1.3ha saturated surface vertical flow wetland at CSBP Ltd, a fertiliser and chemical manufacturer located in Kwinana, Western Australia. From September 2008 to October 2009 water quality was monitored and sediment samples collected for bacterial analyses. During the period of study the wetland received an average inflow of 1109m3/day with NH3-N = 40mg/L and NO3-N=23mg/L. Effluent NH3-N and NO3-N were on average 31mg/L and 25mg/L respectively. The overall NH3-N removal rate for the period was 1.2g/m2/d indicating the nitrifying capacity of the wetland. The structure of the AOB community was analysed using group specific primers for the ammonia monooxygenase gene (amoA) by terminal restriction fragment length polymorphism (T-RFLP) and by clone libraries to identify key members. The majority of sequences obtained were most similar to Nitrosomonas sp. while Nitrosospira sp. was less frequent. Another two vertical flow wetlands, 0.8ha each, were commissioned at CSBP in July 2009, since then the wetland in this study has received nitrified effluent from these two new cells

    Manufacturing of 100mm diameter GaSb substrates for advanced space based applications

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    Engineered substrates such as large diameter (100mm) GaSb wafers need to be ready years in advance of any major shift in DoD and commercial technology, and typically before much of the rest of the materials and equipment for fabricating next generation devices. Antimony based III-V semiconductors are of significant interest for advanced applications in optoelectronics, high speed transistors, microwave devices, and photovoltaics. GaSb demand is increasing due to its lattice parameter matching of various ternary and quaternary III-V compounds, as their bandgaps can be engineered to cover a wide spectral range. For these stealth and spaced based applications, larger format IRFPAs benefit clearly from next generation starting substrates. In this study, we have manufactured and tested 100mm GaSb substrates. This paper describes the characterization process that provides the best possible GaSb material for advanced IRFPA and SLS epi growth. The analysis of substrate by AFM surface roughness, particles, haze, GaSb oxide character and desorption using XPS, flatness measurements, and SLS based epitaxy quality are shown. By implementing subtle changes in our substrate processing, we show that a Sb-oxide rich surface is routinely provided for rapid desorption. Post-MBE CBIRD structures on the 100mm ULD GaSb were examined and reveals a high intensity, 6.6nm periodicity, low (15.48 arcsec) FWHM peak distribution that suggests low surface strain and excellent lattice matching. The Ra for GaSb is a consistent ~0.2-4nm, with average batch wafer warp of ~4 μm to provide a clean, flat GaSb template critical for next generation epi growth

    Dallas Bower: a producer for television's early years, 1936-39

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    Having worked in the film industry as a sound technician and then director, Dallas Bower (1907-99) was appointed in 1936 as one of two senior producers at the start of the BBC Television service. Over the next three years Bower produced as well as directed many ground-breaking live programmes, including the opening-day broadcast on 2 November 1936; the BBC Television Demonstration Film (1937, his only surviving pre-war production); a modern-dress Julius Caesar (1938), in uniforms suggestive of a Fascist disctatorship; Act II of Tristan and Isolde (1938); Patrick Hamilton’s play Rope (1939), utilising extended single camera-shots camera-shots; numerous ballets, among them Checkmate (1938); and ambitious outside broadcasts from the film studios at Denham and Pinewood. Developing the working practices of producing for the theatre, film industry and radio, Bower was a key figure in defining the role of the creative television producer at the start of the medium. Among his innovations, according to his unpublished autobiographical fragment ‘Playback’ (written 1995), was the introduction of a drawn studio plan for the four cameras employed in all live broadcasts from Alexandra Palace. Using Bower’s writings (among them his 1936 book Plan for Cinema), his BECTU History Project interview, the BBC Written Archives and contemporary industry coverage, this article reconstructs the early development of the role of staff television producer in order to consider the questions of autonomy, agency and institutional constraints at the BBC in the pre-war years

    A New Limit on the Antiproton Lifetime

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    Measurements of the cosmic ray pbar/p ratio are compared to predictions from an inhomogeneous disk-diffusion model of pbar production and propagation within the Galaxy, combined with a calculation of the modulation of the interstellar cosmic ray spectra as the particles propagate through the heliosphere to the Earth. The predictions agree with the observed pbar/p spectrum. Adding a finite pbar lifetime to the model, we obtain the limit tau_pbar > 0.8 Myr (90 % C.L.).Comment: 13 pages, 3 encapsulated Postscript figures, uses AASTeX; accepted by Astrophysical Journal; minor change

    Improvement of the Staggered Fermion Operators

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    We present a complete and detailed derivation of the finite lattice spacing corrections to staggered fermion matrix elements. Expanding upon arguments of Sharpe, we explicitly implement the Symanzik improvement program demonstrating the absence of order aa terms in the Symanzik improved action. We propose a general program to improve fermion operators to remove O(a)O(a) corrections from their matrix elements, and demonstrate this program for the examples of matrix elements of fermion bilinears and BKB_K. We find the former does have O(a)O(a) corrections while the latter does not.Comment: 16 pages, latex, 1 figur

    Finishing Beef Cattle on Grass with Self-Fed By-Products

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    There has been increasing interest by consumers in beef from cattle that are finished or fattened “on grass” rather than in a conventional feedlot. Also recently, Iowa has had a proliferation of plants that produce ethanol from corn. The byproduct of this process is distillers dried grains with solubles (DDGS). The objective of this study was to feed beef cattle to market weight by grazing cool-season grass supplemented with self-fed by-product pellets

    Performance and Carcass Traits of Market Beef Cattle Supplemented Self-Fed Byproducts on Pasture: Final Report

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    Over a two year period (2007 and 2008), 162 head of beef steers were finished with self-fed byproducts on cool season grass pastures. Yearling steers were continuously grazed at the Neely-Kinyon Farm in southwest Iowa on cool season grasses that were predominantly fescue at a stocking density of 2.25 head/acre. Half of the cattle were implanted (with Synovex®-S) or half were not. Cattle received a diet of either soyhulls-dried distillers grain with solubles (DDGS) or ground corn-dried distillers grains with solubles that was offered through self-feeders. The rations were mixed at a 1:1 ratio with a mineral balancer added which included Rumensin®. Live cattle performance and carcass traits were not affected by diet. Implanted cattle outgained non-implanted over the entire finishing period (3.52 lbs/d vs. 3.17 lbs/d). This led to implanted cattle coming off test heavier (1324 lbs vs. 1277 lbs) and railing with heavier carcasses (826 lbs vs. 800 lbs). Ribeye areas were greater (13.1 in2 vs. 12.7 in2) for implanted cattle; which was probably due to the heavier carcass weights. Non-implanted cattle had superior quality grades (55% vs. 40%) of low choice or better. Fatty acid profiles from the first year were analyzed and showed that raw beef samples from cattle on the soyhulls diet had significantly higher C18:2 In conclusion, pasture rearing cattle, when given access to self-fed by-products, provides for excellent performance on both live performance and carcass traits. Some considerations should be made by the feeder in regards to time of year when marketing cattle and the cattle’s genetics. This system is an alternative to high-grain conventional beef finishing production in feedlots

    Performance and Carcass Traits of Market Beef Cattle Supplemented Self-Fed Byproducts on Pasture: A Progress Report

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    Over a two year period (2007 and 2008), 162 head of beef steers were finished with self-fed byproducts on cool season grass pastures. Yearling steers were continuously grazed at the Neely-Kinyon Farm in southwest Iowa on cool season grasses that were predominantly fescue at a stocking density of 2.25 head/acre. Half of the cattle were implanted (with Synovex®-S) or and half were not. Cattle received a diet of either soyhulls-dried distillers grain with solubles or corn-dried distillers grains with solubles (DDGS) that was offered as a meal through self-feeders. The rations were mixed in at 1:1 with a mineral balancer that included Rumensin®. Live cattle performance and carcass traits were not affected by diet. Implanted cattle outgained non-implanted over the entire finishing period (3.52 lbs/d vs. 3.17 lbs/d). This led to implanted cattle coming off test heavier (1324 lbs vs. 1277 lbs) and railing with heavier carcasses (826 lbs vs. 800 lbs). Ribeye areas were greater (13.1 in 2 vs. 12.7 in 2 ) for implanted cattle; which was probably due to the heavier carcass weights. Non-implanted cattle had superior quality grades (55% vs. 40%) of low choice or better. Year differences in quality grade (1023 vs. 985 in 2007 and 2008, respectively) were observed. This difference was attributed to factors that include genetic makeup of cattle, initial weights of cattle, time of year when cattle were harvested and grading technology. In conclusion, pasture rearing cattle, when given access to self-fed by-products, provides for excellent performance on both live performance and carcass traits. Some considerations should be made by the feeder in regards to time of year when marketing cattle and the cattle’s genetics. This system is an alternative to high-grain conventional beef finishing production in feedlots
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