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Exploring denitrifying communities in the environment /Noredal Throbäck, Ingela, January 2006 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2006. / Härtill 3 uppsatser.
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Gas-phase chemistry of ICP atomic ions with selected molecules /Lavrov, Vitali. January 2006 (has links)
Thesis (Ph.D.)--York University, 2006. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references. Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NR19763
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The isotopic signature of nitrous oxide emitted from agricultural soils measured by FTIR spectroscopyParkes, Stephen. January 2008 (has links)
Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references.
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Evaluation of success in pediatric dental treatment using nitrous oxide from 2000 to 2005 a.d. at the Geneva Community Children's Dental Clinic /Leonhardt Amar, Juliane. January 2008 (has links)
Diss. med. dent. Zürich. / Literaturverz.
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Continuous measurement of soil surface carbon dioxide, nitrous oxide and methane fluxes to estimate global warming potentials in Great Plains maize-based agroecosystemsShen, Hui. January 2008 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Jan. 15, 2009). PDF text: 147 p. : col. ill. ; 9 Mb. UMI publication number: AAT 3316416. Includes bibliographical references. Also available in microfilm and microfiche formats.
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MANEJO DO SOLO NA ENTRESSAFRA DO ARROZ E SUA INFLUÊNCIA NA EMISSÃO DE GASES DE EFEITO ESTUFA E NA PRODUTIVIDADE DA CULTURA DA SOJA / SOIL MANAGEMENT IN RICE INTER-CROPPING AND ITS INFLUENCE ON GREENHOUSE GASES EMISSION AND SOYBEAN CROP PRODUCTIVITYRosalino, Pedro Krauspenhar 12 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The soybean (Glycine max) cultivation in rotation with rice (Oryza sativa) in paddy soils is a growing practice in the state of Rio Grande do Sul. However, there is little information on the emission of methane (CH4) and nitrous oxide (N2O) during soybean growing season in lowland and the contribution of biological nitrogen fixation (BNF) for crops in this environment. The study was aimed to evaluate the emissions of CH4 and N2O, BNF and soybean productivity in lowland managed for three years with different systems of soil tillage/straw after the rice harvest. The experiment was conducted during the growing season of 2012/2013 on a Plano soil. The treatments consisted of different systems of soil management/straw applied for three years after the rice harvest: ryegrass (RY), disc harrow (DH), knife-roller (KR), fallow + disc harrow (F + DH), disc harrow + disc harrow (DH + DH), knife-roller + disc harrow (KR + DH), removal of straw (RS) and fallow (F). Besides these, a natural lowland (NL) was used as control. The NL had the lowest N2O emissions; however CH4-C (161 kg ha-1) emissions were higher when compared to soybean cultivated in lowland. The highest N2O emissions occurred from soybean cultivation, being observed in the treatment RY where the highest cumulative emission was 7.9 kg N2O-N ha-1. The management of soil/straw performed with DH, compared to systems with KR and F, caused increased density by up to 10% and reduction in macro-porosity and total porosity in the topsoil. Changes in soil physical properties caused by different soil/straw tillage systems did not result in a decreased N accumulation, BNF contribution (mean 67%) and productivity of soybean. / O cultivo da soja (Glycine Max) em rotação com o arroz (Oryza sativa) em solos de várzea é uma prática crescente no estado do Rio Grande do Sul (RS). No entanto, existem poucas informações sobre a emissão de metano (CH4) e óxido nitroso (N2O) durante o cultivo da soja em várzea e a contribuição da fixação biológica (FBN) para a cultura nesse ambiente. O estudo teve por objetivo avaliar as emissões de CH4 e N2O, a FBN e a produtividade da soja em várzea manejada durante três anos com diferentes sistemas de manejo do solo/palha após a colheita do arroz. O experimento foi conduzido no ano agrícola 2012/2013 em um Planossolo Hidromórfico Eutrófico arênico. Os tratamentos foram compostos por diferentes sistemas de manejo do solo/palha aplicados durante três anos após a colheita do arroz: azevém (AZ), grade (G), rolo-faca (RF), pousio + grade (P+G), grade + grade (G+G), rolo-faca + grade (RF+G), retirada da palha (RP) e pousio (P). Além desses, foi avaliada uma área natural de banhado (AN) que serviu como testemunha. A AN apresentou as menores emissões de N2O, porém elevada emissão de C-CH4 (161 kg ha-1) quando comparada ao cultivo da soja em várzea. As maiores emissões de N2O ocorreram no período de cultivo da soja, sendo observada no tratamento AZ a maior emissão acumulada desse gás (7,9 kg de N-N2O ha-1). O manejo do solo/palha realizado com G, comparado aos sistemas com RF e P, provocam aumento da densidade em até 10% e redução na macroporosidade e porosidade total na camada superficial do solo. As modificações causadas nos atributos físicos do solo pelos diferentes sistemas de manejo do solo/palha, não resultaram em diminuição no acúmulo de N, contribuição da FBN (média de 67%) e produtividade de grãos de soja.
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Lustgasbehandling vid smärtsamma procedurer : En utvärdering av lustgasbehandling på barnBerggren, Johanna, Lohus, Frida January 2018 (has links)
Bakgrund: Barn som besöker vården upplever rädsla och oro inför att vårdåtgärder kan tänkas göra ont. Adekvat smärtlindring är viktig för att lindra barns fysiska och psykiska smärta samt främja god hälsa. Det finns olika sätt att lindra barns smärta, en metod är lustgasbehandling. Syfte: Syftet var att i form av ett förbättringsarbete utvärdera lustgasbehandling i samband med att barn genomgår en smärtsam procedur på en barn- och ungdomsmedicinsk klinik på ett medelstort sjukhus i södra Sverige. Metod: Förbättringsarbetet genomfördes med en kvantitativ design. Deskriptiv statistik har använts för att utvärdera lustgasens effekter och bieffekter, vidare har andra faktorer som kan påverka behandlingen utvärderats. Resultat: Lustgas har varit användbart i samband med smärtsamma procedurer, behandlingen har fungerat smärtlindrande samt varit till hjälp för barn som varit rädda. Lustgasbehandling uppskattas av både barn och deras vårdnadshavare. Slutsatser: För att lindra barns lidande och utföra god omvårdnad måste barnsjuksköterskan ha kunskap om hur barn upplever smärtsamma situationer samt hur smärta bäst lindras. Det aktuella förbättringsarbetet har bekräftat att lustgas är en metod som kan hjälpa barn i samband med flera typer av smärtsamma procedurer. Genom att kunna välja lustgas som smärtlindrande och lugnande metod kan barnets delaktighet och hälsa främjas. / Background: Children receiving health care experience fear and anxiety related to possible painful procedures. Adequate pain relief is important to ease children’s physical and psychological pain and further to promote good health. There are various ways of relieving children’s pain, one method is nitrous oxide. Aim: The aim was to through an improvement work evaluate the usage of nitrous oxide in connection to children undergoing a painful procedure on a children’s and youth’s medicine ward at a medium sized hospital in south of Sweden. Method: The improvement work was conducted through a quantitative design. Descriptive statistics was used to evaluate the effects and adverse events of nitrous oxide, furthermore has other variables that may affect the treatment been evaluated. Results: Nitrous oxide has been useful when utilized in painful procedures, the treatment has served pain relieving and eased children who experienced fear. Both children and legal guardians appreciated the usage of nitrous oxide. Conclusion: A children’s nurse must possess knowledge related to children’s experience of pain and adequate pain relief in order to ease children’s suffering and administer good care. The current improvement work has confirmed nitrous oxide to be a tool that might help children in connection to several painful procedures. Through the choice of using nitrous oxide as a pain relieving and sedative method the child’s empowerment and health can be improved.
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Denitrification and Greenhouse Gas Dynamics in Lakes Receiving Atmospheric Nitrogen DepositionJanuary 2010 (has links)
abstract: The global transport and deposition of anthropogenic nitrogen (N) to downwind ecosystems are significant and continue to increase. Indeed, atmospheric deposition can be a significant source of N to many watersheds, including those in remote, unpopulated areas. Bacterial denitrification in lake sediments may ameliorate the effects of N loading by converting nitrate (NO3-) to N2 gas. Denitrification also produces nitrous oxide (N2O), a potent greenhouse gas. The ecological effects of atmospheric N inputs in terrestrial ecosystems and the pelagic zone of lakes have been well documented; however, similar research in lake sediments is lacking. This project investigates the effects N of deposition on denitrification and N2O production in lakes. Atmospheric N inputs might alter the availability of NO3- and other key resources to denitrifiers. Such altered resources could influence denitrification, N2O production, and the abundance of denitrifying bacteria in sediments. The research contrasts these responses in lakes at the ends of gradients of N deposition in Colorado and Norway. Rates of denitrification and N2O production were elevated in the sediments of lakes subject to anthropogenic N inputs. There was no evidence, however, that N deposition has altered sediment resources or the abundance of denitrifiers. Further investigation into the dynamics of nitric oxide, N2O, and N2 during denitrification found no difference between deposition regions. Regardless of atmospheric N inputs, sediments from lakes in both Norway and Colorado possess considerable capacity to remove NO3- by denitrification. Catchment-specific properties may influence the denitrifying community more strongly than the rate of atmospheric N loading. In this regard, sediments appear to be insulated from the effects of N deposition compared to the water column. Lastly, surface water N2O concentrations were greater in high-deposition lakes compared to low-deposition lakes. To understand the potential magnitude of deposition-induced N2O production, the greenhouse gas inventory methodology of Intergovernmental Panel on Climate Change was applied to available datasets. Estimated emissions from lakes are 7-371 Gg N y-1, suggesting that lakes could be an important source of N2O. / Dissertation/Thesis / Ph.D. Biology 2010
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Carbon and nitrogen cycling in Scottish upland grassland soils and the influence of excretal returnsStack, Philip Eugene January 2018 (has links)
Upland grasslands comprise a large proportion of the UK’s land area and are primarily used to graze sheep. These grasslands store large quantities of carbon (C). Changes in land use or climate could affect the ability of these soils to store C and the fluxes of other greenhouse gases associated with agricultural soils, nitrous oxide (N2O) and methane (CH4). Grazing substantially changes the cycling of C and nitrogen in grassland ecosystems, particularly through the deposition of rapidly degrading excreta, both dung and urine, on the soil. The major non-enteric greenhouse gas emissions associated with this type of extensive farming of ruminants are the emission of N2O and CH4 from soils affected by the animal’s excreta. This PhD project has investigated the cycling of sheep dung in two upland soils of different management regimes to investigate the effects imposed by the plant community. Dung incorporation was measured by capitalising on the natural difference in natural 13C abundance (δ13C ratios) between maize and native British vegetation, which permitted maize-derived sheep dung to be used as a 13C tracer of dung incorporation into soil. A physical and chemical soil fractionation methodology was used to isolate the distinct soil organic carbon (SOC) pools and ascertain the location of the dung C. There were differences between soils in dung C cycling, with more dung C being measured in semi-improved soils at experiment’s end. Throughout the one year timeframe of this experiment, most of the dung C was recovered in the particulate organic matter fraction. Changing the plant community did not have a measurable effect on dung C cycling within the experimental period. Urine patches in grazed pastures represent a major source of agriculture’s N2O emissions. The N2O, CH4 and CO2 fluxes from chambers treated with synthetic urine, synthetic urine and dung, or dung, and an untreated control in randomised block design at two sites were measured over one year. Relevant soil parameters were also measured at each sampling point. From this data N2O emission factors for sheep excreta at these sites were calculated. N2O emission factors were significantly different between sites, were different for dung and urine, and in all cases were less than the current default value used by countries utilising a Tier 1 methodology, according to the IPCC, to inventory N2O emissions derived from grazing livestock. Dietary manipulation has been proposed to increase certain components in urine that are thought to inhibit N2O emission with the aim of reducing livestock greenhouse gas emissions. One such urinary component is hippuric acid. Soil to which synthetic urine with incrementally increased quantities of hippuric acid were added were incubated, as were soils to which dung only and dung and synthetic urine had been added, as well as an untreated control. No significant effect of hippuric acid concentration was observed. N2O emissions from the dung only and dung and urine treatments were unusually high and surpassed those of the urine only treatments. This has been hypothesised to be due to fungal denitrification in the dung treatments or suppression of microbial activity due to ammonia toxicity in the urine-treated soils. The key conclusions from this PhD work are that the effect of dung deposition on SOC cycling may be quite small and appears to result in substitution of native SOC with dung C, rather than an increase in SOC; N2O emissions from sheep dung and urine deposition in semi-improved grasslands is likely to be very low and much lower than the current IPCC default value; and that in our incubation experiment there was no discernible impact of hippuric acid on N2O emissions, but it is possible that this is an experimental artefact.
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Assessment of nutrient emission factors for different manure and digestate management systemsRyding, Caroline January 2018 (has links)
An efficient management of organic fertilizers (here animal manure and digestate) is of large concern in today´s agriculture. When evaluating the efficiency of alternative management systems, differences in nutrient losses (emissions) must be taken into consideration. Those can be rather specific for e.g. a geographical region and agricultural system. This literature study aimed at identifying emission factors and uncertainty ranges, that are relevant to use in comparative system studies of different organic fertilizer management systems in South Swedish climate. Emissions from manure and digestate storage, application and field losses were considered. For carbon, the sequestration of organic carbon in the soil was considered instead of the carbon dioxide emissions from manure/digestate decomposition in soils. The values were very variable, and the median value was used as the selected emission factor. From storage of liquid cow manure, the ammonia emission for storage with cover was 3 % of the ammonium content, and 10 % without cover. It was about the same for both liquid pig manure (8 %) and solid cattle manure (10 %). The methane emissions during storage were 10 % of the maximum methane potential. Ammonia emissions during application ranged from 10-20 % of ammonium-nitrogen. Two studies of manure carbon sequestration were found that was applicable for the Swedish climate. They indicated that about 8-11 % of the carbon applied as solid manure was sequestered, compared to about 4 % for liquid manure.
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