1,393 research outputs found

    Soil fertility research and extension in Oregon

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    Non-Peer ReviewedThis report describes our approach to and philosophy behind development of soil fertility research and Extension programs at Oregon State University since 1980. Three examples describe how fertilizer management was used to minimize crop loss to a plant disease, protect groundwater quality, and enhance crop production efficiency. Instead of presenting data, we reference published research and management recommendations

    Importance of Vanadium-Catalyzed Oxidation of SO2 to SO3 in Two-Stroke Marine Diesel Engines

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    Low-speed marine diesel engines are mostly operated on heavy fuel oils, which have a high content of sulfur and ash, including trace amounts of vanadium, nickel, and aluminum. In particular, vanadium oxides could catalyze in-cylinder oxidation of SO2 to SO3, promoting the formation of sulfuric acid and enhancing problems of corrosion. In the present work, the kinetics of the catalyzed oxidation was studied in a fixed-bed reactor at atmospheric pressure. Vanadium oxide nanoparticles were synthesized by spray flame pyrolysis, i.e., by a mechanism similar to the mechanism leading to the formation of the catalytic species within the engine. Experiments with different particle compositions (vanadium/sodium ratio) and temperatures (300–800 °C) show that both the temperature and sodium content have a major impact on the oxidation rate. Kinetic parameters for the catalyzed reaction are determined, and the proposed kinetic model fits well with the experimental data. The impact of the catalytic reaction is studied with a phenomenological zero-dimensional (0D) engine model, where fuel oxidation and SOx formation is modeled with a comprehensive gas-phase reaction mechanism. Results indicate that the oxidation of SO2 to SO3 in the cylinder is dominated by gas-phase reactions and that the vanadium-catalyzed reaction is at most a very minor pathway

    Estudio de la oxidación de SO2 a SO3 con catalizadores basados en vanadio. Aplicación a motores marinos diésel de dos tiempos

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    Los grandes barcos utilizan generalmente motores diesel de dos tiempos, funcionan con fuelóleo pesado, que contiene grandes cantidades de azufre y vanadio. Por ello, es posible que se de lugar a la formación de ácido sulfúrico y que lleve a la llamada corrosión fría. Este trabajo pretende determinar la influencia de la presencia de vanadio sobre la conversión de SO2 y, por tanto, sobre la corrosió fría

    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

    The Certification of the Mass Concentrations of Aluminium, Selenium and Zinc in Human Serum, BCR-637, BCR-638, BCR-639.

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    Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel

    Actinomyces species: A Danish Survey on Human Infections and Microbiological Characteristics

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    This study compared phenotypic and genotypic identification of Actinomyces strains, tested susceptibility to antibiotics and evaluated their clinical importance. Thirty-four Actinomyces strains were examined; sixteen type strains, and 18 clinical strains from different hospitals in Denmark from the period 2003-2005. Partial 16S rDNA sequencing using a stretch of 526 bases was used for genotypic identification. Susceptibility testing was done by E-test. The antibiotics examined were: benzylpenicillin, piperacillin with tazobactam, ceftriaxone, meropenem, erythromycin, clindamycin, linezolid, moxifloxacin, tetracycline and tigecycline. Clinical parameters were obtained by reviewing patient records. There was poor agreement between the phenotypic and genotypic identification. Phenotypic tests were helpful in identifying strains closely related by DNA sequences. The strains were sensitive to the examined antibiotics except for moxifloxacin to which most strains were resistant, and a few strains were resistant to meropenem and tetracycline. The clinical strains were from many different types of infections and locations. None of the patients was described as having typical actinomycetic lesions, and an apparently good outcome was obtained with different treatment regimens

    The Certification of the Mass Concentrations of Lead and Cadmium in Reconstituted Human Blood. BCR-634, BCR-635, BCR-636.

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    Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel

    The relationships between early lactation energy status indicators and endocrine fertility traits in dairy cows

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    The relationships between dairy cow milk-based energy status (ES) indicators and fertility traits were studied during periods 8 to 21, 22 to 35, 36 to 49, and 50 to 63 d in milk. Commencement of luteal activity (C -LA) and interval from calving to the first heat (CFH), based on frequent measurements of progesterone by the management tool Herd Navigator (DeLaval), were used as fertility traits. Energy status indicator traits were milk beta-hydroxybutyrate (BHB) concentration provided by Herd Navigator and milk fat: protein ratio, concen-tration of C18:1 cis-9, the ratio of fatty acids (FA) C18:1 cis-9 and C10:0 in test-day milk samples, and predicted plasma concentration of nonesterified fatty acids (NEFA) on test days. Plasma NEFA predictions were based either directly on milk mid-infrared spectra (MIR) or on milk fatty acids based on MIR spectra (NEFAmir and NEFAfa, respectively). The average (standard deviation) C-LA was 39.3 (+/- 16.6) days, and the average CFH was 50.7 (+/- 17.2) days. The correlations between fertility traits and ES indicators tended to be higher for multiparous (r < 0.28) than for primiparous (r < 0.16) cows. All correlations were lower in the last period than in the other periods. In period 1, correlations of C-LA with NEFAfa and BHB, respectively, were 0.15 and 0.14 for primiparous and 0.26 and 0.22 for multiparous cows. The associations between fertility traits and ES indicators indicated that negative ES during the first weeks postpartum may delay the onset of luteal activity. Milk FPR was not as good an indicator for cow ES as other indicators. According to these findings, predictions of plasma NEFA and milk FA based on milk MIR spectra of routine test-day samples and the frequent measurement of milk BHB by Herd Navigator gave equally good predictions of cow ES during the first weeks of lactation. Our results indicate that routinely measured milk traits can be used for ES evaluation in early lactation.Peer reviewe

    Patterns of epidemiology and control of onchocerciasis in West Africa

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    This paper summarizes the work of the Onchocerciasis Control Programme (OCP) in West Africa, a programme which over a 22 year history has reduced the public health problems of blinding onchocerciasis in eleven countries of West Africa through vector control and, more recently, ivermectin distribution. The paper emphasizes the different approaches to control the programme has developed in the different parts of the programme area which have been determined by the epidemiology of the disease (savanna/forest form), the migratory characteristics of the vectors, intensity of the disease before commencement of treatment, the combined impact of vector control and ivermectin and the likelihood of infiltration of infective blackflies from outside the programme area. The programme has constantly monitored the impact of operations on the trends in prevalence, incidence, annual transmission potential, ocular morbidity and species of fly populations, and as a result, has identified areas where special interventions are required until the programme comes to an end in 2002. The paper illustrates the changes in intensity of infection as measured by community microfilarial load and annual transmission potential over the duration of the programme control activities. The paper also defines and justifies the control strategies in different areas and identifies areas for special intervention

    Tensors, non-Gaussianities, and the future of potential reconstruction

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    We present projections for reconstruction of the inflationary potential expected from ESA's upcoming Planck Surveyor CMB mission. We focus on the effects that tensor perturbations and the presence of non-Gaussianities have on reconstruction efforts in the context of non-canonical inflation models. We consider potential constraints for different combinations of detection/null-detection of tensors and non-Gaussianities. We perform Markov Chain Monte Carlo and flow analyses on a simulated Planck-precision data set to obtain constraints. We find that a failure to detect non-Gaussianities precludes a successful inversion of the primordial power spectrum, greatly affecting uncertainties, even in the presence of a tensor detection. In the absence of a tensor detection, while unable to determine the energy scale of inflation, an observable level of non-Gaussianities provides correlations between the errors of the potential parameters, suggesting that constraints might be improved for suitable combinations of parameters. Constraints are optimized for a positive detection of both tensors and non-Gaussianities.Comment: 12 pages, 5 figures, LaTeX; V2: version submitted to JCA
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