357 research outputs found

    Health Impacts of Ultrafine Particles

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    This document captures proceedings from a workshop on the health impacts of ultrafine particles held on 15 September 2020, under the Aviator, Raptor and Tube projects

    Regulation of nitrogen uptake and assimilation: Effects of nitrogen source and root-zone and aerial environment on growth and productivity of soybean

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    The interdependence of root and shoot growth produces a functional equilibrium as described in quantitative terms by numerous authors. It was noted that bean seedlings grown in a constant environment tended to have a constant distribution pattern of dry matter between roots and leaves characteristic of the set of environmental conditions. Disturbing equilibrium resulted in a change in relative growth of roots and leaves until the original ratio was restored. To define a physiological basis for regulation of nitrogen uptake within the balance between root and shoot activities, the authors combined a partioning scheme and a utilization priority assumption in which: (1) all carbon enters the plant through photosynthesis in leaves and all nitrogen enters the plant through active uptake by roots, (2) nitrogen uptake by roots and secretion into the xylem for transport to the shoots are active processes, (3) availability of exogenous nitrogen determines concentration of soluble carbohydrates within the roots, (4) leaves are a source and a sink for carbohydrates, and (5) the requirement for nitrogen by leaf growth is proportionally greater during initiation and early expansion than during later expansion

    ADOPTION OF BEST MANAGEMENT PRACTICES IN STOCKER CATTLE PRODUCTION

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    This study identifies current production and management practices of Oklahoma stocker cattle producers and analyzes factors affecting the adoption of best management practices (BMPs) using chi-square analysis. Results reveal that factors influencing the adoption of BMPs are operation size, dependency upon income from the operation, and specialization in stocker production.cattle, stockers, management, production, Livestock Production/Industries,

    Aviator - assessing aviation emissions impact on local air quality at airports towards regulation

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    Emissions from aircraft have adverse effects on the air quality in and around airports, contributing to public health concerns within neighbouring communities. A VIA TOR will adopt a multi-level measurement, modelling and assessment approach to develop an improved description and quantification of the relevant aircraft engine emissions, and their impact on air quality under different climatic conditions. Particulate and gaseous emissions in a test cell and on-wing from an in-service aircraft will be measured to determine pollutant plume evolution from the engine and APU exhaust. This will provide an enhanced understanding of primary emitted pollutants, specifically the nvPM and vPM (down to 10nm), and the scalability between the regulatory test cell and real environments. AVIATOR will develop and deploy a proof-of-concept low cost sensor network for monitoring UFP, PM and gaseous species across multiple airports and surrounding communities. Campaigns will be complemented by high-fidelity modelling of aircraft exhaust dynamics, microphysical and chemical processes within the plume. CFD, box, and airport air quality models will be applied, providing validated parameterisations of the relevant processes, applicable to standard dispersion modelling on the local scale. Working with the regulatory community, AVIATOR will develop improved guidance on measuring and modelling the impact of aircraft emissions, and will provide airports and regulators with tools and guidance to improve the assessment of air quality in and around airports

    Demographic Factors Affecting the Adoption of Multiple Value-Added Practices by Oklahoma Cow-Calf Producers

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    The utilization of marketing programs to enhance feeder calf value has been met with modest success in Oklahoma. Value-added programs are continually promoted as avenues for improving cow-calf profitability, but producer adoption of value-added practices lags in spite of research showing the value of these practices. Identifying producer characteristics that increase their likelihood to adopt value-added practices is critical to developing successful outreach efforts. Results from a survey of Oklahoma producers on value-added practice adoption indicate that multiple demographic variables influence a producer’s likelihood of practice adoption. For Extension specialists, results can help in targeting likely adopters and developing methods to overcome barriers to adoption by producers less likely to adopt.Beef producers, value-added practices, practice adoption, negative binomial regression, Poisson regression, Farm Management, Livestock Production/Industries, Q12, Q16,

    Enhancing the removal of pollutants from coke wastewater by bioaugmentation: a scoping study

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    BACKGROUND Bioaugmentation and biostimulation were investigated for their ability to improve the removal of thiocyanate (SCN-), polycyclic aromatic hydrocarbons (PAHs), phenol and trace metals in coke wastewater. Additionally, the ability of the microorganisms supplemented with the bioaugmentation product to survive in a simulated river water discharge was evaluated. RESULTS A commercially available bioaugmentation product composed mainly of Bacillus sp. was mixed with activated sludge biomass. A dose of 0.5 g/L increased the removal of Æ©6PAHs (sum of fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene) by 51% and reduced SCN- below 4 mg/L enabling compliance with the EU Industrial Emissions Directive (IED). Biostimulation (supplementing micronutrients and alkalinity) allowed compliance for both SCN- and phenol (<0.5 mg/L). Bacillus sp. accounted for 4.4% of the microbial population after 25 hours (1.5 g/L dose) which declined to 0.06% after exposure to river water (24 hours). Exposure of the activated sludge biomass to river water resulted in a 98.6% decline in viable cell counts. CONCLUSION To comply with the IED, bioaugmentation and biostimulation are recommended for the treatment of coke wastewater to enable an effluent Æ©6PAHs of 6.6 ÎŒg/L, 0.3 mg/L phenol and 1.2 mg/L SCN-. Such techniques are not anticipated to impact on downstream river water quality

    Cyclic Variations in Nitrogen Uptake Rate of Soybean Plants

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    The application of AEM to mapping the aquifer and groundwater characteristics of the La Grange groundwater area, WA

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    This report describes the interpretation of a large airborne electromagnetic data survey that was designed to aid characterisation of groundwater systems in the La Grange groundwater allocation area which lies south of Broome, Western Australia. Characterisation of these systems is critical to developing policy around water use in the region, especially for the development of agriculture. This report is the second of two reports and it is designed to refine surfaces which are used as inputs to groundwater models. The volume defined by these surfaces viz. the seawater intrusion in the west, the top of the Jarlemai siltstone and the top of the Broome sandstone describes the portion of the Broome sandstone aquifer that is able to store water that can be used for human purposes, agriculture and mining. With the identification of palaeochannels in the La Grange groundwater allocation area and an improved analysis of geological structure from AEM results, most objectives of the survey have been realised. Palaeochannels were identified in the north of the La Grange groundwater allocation area, around La Grange Bay, and also in the south. Also in the south, faults were identified. It is hypothesised that these faults permit groundwater movement between the Broome sandstone, which is the important aquifer in the La Grange groundwater allocation area, and the Wallal sandstone which is the important aquifer south of the allocation area. Objectives relating to delineation of freshwater zones, and of water quality were not addressed. Although the top of the seawater intrusion was mapped, as was the top of the Broome sandstone near the coast, because freshwater and the sandstone matrix have similar electrical resistivities, it is difficult to map freshwater specifically

    Characterisation of thiocyanate degradation in a mixed culture activated sludge process treating coke wastewater

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    Microbial degradation of thiocyanate (SCN−) has been reported to suffer from instability highlighting the need for improved understanding of underlying mechanisms and boundaries. Respirometry, batch tests and DNA sequencing analysis were used to improve understanding of a mixed culture treating coke wastewater rich in SCN−. An uncultured species of Thiobacillus was the most abundant species (26%) and displayed similar metabolic capabilities to Thiobacillus denitrificans and Thiobacillus thioparus. Thiocyanate was hydrolysed/oxidised to NH4+-N, HCO3− and SO42−. Nevertheless, at 360–2100 mg SCN−/L a breakdown in the degradation pathway was observed. Respirometry tests demonstrated that NH4+-N was inhibitory to SCN− degradation (IC50: 316 mg/L). Likewise, phenol (180 mg/L) and hydroxylamine (0.25–16 mg/L) reduced SCN− degradation by 41% and ca. 7%, respectively. The understanding of the SCN− degradation pathways can enable stable treatment efficiencies and compliance with effluent of <4 mg SCN/L, required by the Industrial Emissions Directive
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