19 research outputs found

    Life cycle modelling of environmental impacts of application of processed organic municipal solid waste on agricultural land (EASEWASTE)

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    A model capable of quantifying the potential environmental impacts of agricultural application of composted or anaerobically digested source-separated organic municipal solid waste (MSW) is presented. In addition to the direct impacts, the model accounts for savings by avoiding the production and use of commercial fertilizers. The model is part of a larger model, Environmental Assessment of Solid Waste Systems and Technology (EASEWASTE), developed as a decisionsupport model, focusing on assessment of alternative waste management options. The environmental impacts of the land application of processed organic waste are quantified by emission coefficients referring to the composition of the processed waste and related to specific crop rotation as well as soil type. The model contains several default parameters based on literature data, field experiments and modelling by the agro-ecosystem model, Daisy. All data can be modified by the user allowing application of the model to other situations. A case study including four scenarios was performed to illustrate the use of the model. One tonne of nitrogen in composted and anaerobically digested MSW was applied as fertilizer to loamy and sandy soil at a plant farm in western Denmark. Application of the processed organic waste mainly affected the environmental impact categories global warming (0.4–0.7 PE), acidification (–0.06 (saving)–1.6 PE), nutrient enrichment (–1.0 (saving)–3.1 PE), and toxicity. The main contributors to these categories were nitrous oxide formation (global warming), ammonia volatilization (acidification and nutrient enrichment), nitrate losses (nutrient enrichment and groundwater contamination), and heavy metal input to soil (toxicity potentials). The local agricultural conditions as well as the composition of the processed MSW showed large influence on the environmental impacts. A range of benefits, mainly related to improved soil quality from long-term application of the processed organic waste, could not be generally quantified with respect to the chosen life cycle assessment impact categories and were therefore not included in the model. These effects should be considered in conjunction with the results of the life cycle assessment

    Physical Processes in Star Formation

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    © 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00693-8.Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to high-redshift galaxies. From a theoretical perspective, star formation and feedback processes (radiation, winds, and supernovae) play a pivotal role in advancing our understanding of the physical processes at work, both individually and of their interactions. In this review we will give an overview of the main processes that are important for the understanding of star formation. We start with an observationally motivated view on star formation from a global perspective and outline the general paradigm of the life-cycle of molecular clouds, in which star formation is the key process to close the cycle. After that we focus on the thermal and chemical aspects in star forming regions, discuss turbulence and magnetic fields as well as gravitational forces. Finally, we review the most important stellar feedback mechanisms.Peer reviewedFinal Accepted Versio

    Laboratory handling of Helicobacter pylori critically influences the results of in-vitro metronidazole resistance determination

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    ABSTRACTIn-vitro metronidazole resistance rates of Helicobacter pylori determined by Etest are high, and the predictive value of metronidazole resistance is low. It was hypothesised that altered laboratory methods could reduce the overestimation of resistance and improve the predictive value of the Etest. Pre-treatment isolates (n = 150) of H. pylori from 150 patients were investigated by Etest with incubation for 72 h. Treatment with metronidazole, tetracycline and bismuth for 10 days failed to eradicate H. pylori in 23 patients. After isolate storage for 3 years, resistance determination results by agar dilution and Etest, with incubation for 72 and 31 h, were compared. The rate of metronidazole resistance was reduced significantly during storage, and instability of resistance was associated significantly with treatment outcome. Isolates that retained in-vitro resistance had significantly (p 0.008) higher treatment failure rates (n = 13; 42%) than isolates that lost resistance (n = 3; 9%). The reproducibility achieved by dual testing with agar dilution and Etest was 41% and 70% for ±1 and ±2 log2 dilutions, respectively, after incubation for 72 h, and 85% and 92%, respectively, after incubation for 31 h. Thus, the predictive value was improved from 25% to 50% by the altered laboratory conditions (p 0.04). MIC values of 2–8 mg/L signified an intermediate risk of treatment failure
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