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Mendez-Delgado, Aida. "Nitrogen transport and dynamics in grass filter strips." Diss., Virginia Tech, 1996. http://hdl.handle.net/10919/39047.
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Stenström, Ylva. "Phosphorus and Nitrogen Removalin Modified Biochar Filters." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-321915.
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Onsite wastewater treatment systems in Sweden are getting old and many of them lack sufficient phosphorus, nitrogen and organic carbon reduction. Biochar is a material that has been suggested as an alternative to the common sand or soil used in onsite wastewater treatment systems. The objective of this study was to compare the phosphorus removal capacity between three different modified biochars and one untreated biochar in a batch adsorption and column filter experiment. The modifications included impregnation of ferric chloride (FeCl3), calcium oxide (CaO) and untreated biochar mixed with the commercial phosphorus removal product Polonite. To further study nitrogen removal a filter with one vertical unsaturated section followed by one saturated horizontal flow section was installed. The batch adsorption experiment showed that CaO impregnated biochar had the highest phosphorus adsorption, i.e. of 0.30 ± 0.03 mg/g in a 3.3 mg/L phosphorus solution. However, the maximum adsorption capacity was calculated to be higher for the FeCl3 impregnated biochar (3.21 ± 0.01 mg/g) than the other biochar types. The pseudo 2nd order kinetic model proved better fit than the pseudo 1st order model for all biochars which suggest that chemical adsorption was important. Phosphorus adsorption to the untreated and FeCl3 impregnated biochar fitted the Langmuir adsorption isotherm model best. This indicates that the adsorption can be modeled as a homogenous monolayer process. The CaO impregnated and Polonite mixed biochars fitted the Freundlich adsorption model best which is an indicative of heterogenic adsorption. CaO and FeCl3 impregnated biochars had the highest total phosphorus (Tot-P) reduction of 90 ± 8 % and 92 ± 4 % respectively. The Polonite mixed biochar had a Tot-P reduction of 65 ± 14 % and the untreated biochar had a reduction of 43 ± 24 %. However, the effluent of the CaO impregnated biochar filter acquired a red-brown tint and a precipitation that might be an indication of incomplete impregnation of the biochar. The FeCl3 effluent had a very low pH. This can be a problem if the material is to be used in full-scale treatment system together with biological treatment for nitrogen that require a higher pH. The nitrogen removal filter showed a total nitrogen removal of 62 ± 16 % which is high compared to conventional onsite wastewater treatment systems. Batch adsorption and filter experiment confirms impregnated biochar as a promising replacement or addition to onsite wastewater treatment systems for phosphorus removal. However the removal of organic carbon (as chemical oxygen demand COD) in the filters was lower than expected and further investigation of organic carbon removal needs to be studied to see if these four biochars are suitable in real onsite wastewater treatment systems.Många av Sveriges små avloppssystem är gamla och saknar tillräcklig rening av fosfor, kväve och organiskt material. Följden är förorenat grundvatten samt övergödning i hav, sjöar och vattendrag. Lösningar för att förbättra fosfor- och kvävereningen finns på marknaden men många har visat brister i rening och robusthet. Biokol är ett material som har föreslagits som ersättare till jord eller sand i mark och infiltrationsbäddar. Denna studie syftade till att i skak- och kolonnfilterexperiment jämföra fosforreduktion mellan tre modifierade biokol och ett obehandlat biokol. Modifieringen av biokolet innebar impregnering med järnklorid (FeCl3), kalciumoxid (CaO) samt blandning med Polonite som är en kommersiell produkt för fosforrening. För att undersöka förbättring av kväverening installerades även ett filter med obehandlat biokol där en vertikal aerob modul kombinerades med en efterföljande horisontell anaerob modul. Skakstudien där biokolen skakades i 3.3 mg/L fosforlösning visade att adsorptionen var högst i det CaO-impregnerade biokolet, 0.3 ± 0.03 mg/g. Den maximala potentiella fosforadsorptionen beräknades dock vara högst för biokolet som impregnerats med FeCl3, 3.21 ± 0.01 mg/g. Skakförsöket visade också att fosforadsorptionen var främst kemisk då adsorptionen passade bättre med pseudo andra ordningens modell än pseudo första. Adsorption av fosfor på obehandlat biokol och FeCl3 impregnerat biokol modellerades bäst med Langmuir modellen, vilket tyder på en homogen adsorption. Det Polonite-blandade biokolet och CaO-impregnerade biokolet modellerades bäst med Freundlich modellen vilket är en indikation på en heterogen adsorptionsprocess. Biokol impregnerat med CaO och FeCl3 gav de högsta totalfosforreduktionerna på 90 ± 8 % respektive 92 ± 4 %. Biokolet som var blandat med Polonite hade en reduktion på 65 ± 14 % och det obehandlade biokolet 43 ± 24 %. Ett problem med filtratet från CaO-filtret var att det fick en rödbrun färg samt en fällning vilket kan ha berott på ofullständig pyrolysering och impregnering. Filtratet från det FeCl3 impregnerade biokolet hade mycket lågt pH vilket kan vara problematiskt om mikrobiologisk tillväxt i filtret för rening av kväve och organiskt material vill uppnås. Filtret för kväverening gav en total kvävereduktion på 62 ± 16 % vilket är högre än kommersiella system. Resultaten från skak och filterstudien visade på att impregnerade biokol kan ge en förbättrad fosforrening om de skulle användas i små avloppssystem. Rening av organiskt material, kemisk syreförbrukning (COD), var dock låg i alla filter och behöver studeras ytterligare för att avgöra om dessa biokol är lämpliga för småskalig avloppsvattenrening.
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Blanco-Canqui, Humberto. "Grass barrier and vegetative filter strip effectiveness in reducing runoff, sediment, nitrogen, and phosphorus losses /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3115525.
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Renman, Agnieszka. "On-site wastewater treatment : Polonite and other filter materials for removal of metals, nitrogen and phosphorus." Doctoral thesis, KTH, Mark- och vattenteknik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4811.
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Bed filters using reactive materials are an emerging technology for on-site wastewater treatment. Chemical reactions transfer contaminants from the aqueous to the solid phase. Phosphorus is removed from domestic wastewater by sorption to filter materials, which can then be recycled to agriculture as fertilisers and soil amendments. This thesis presents long-term column and field-scale studies of nine filter materials, particularly the novel product Polonite®. Phosphorus, nitro-gen and metals were removed by the mineral-based materials to varying degrees. Polonite and Nordkalk Filtra P demonstrated the largest phosphorus removal capacity, maintaining a PO4-P removal efficiency of >95%. Analysis of filter bed layers in columns with downward wastewater flow, showed that phosphorus, carbon and nitrogen content was vertically distributed, with de-creasing values from surface to base layer. Polonite and Filtra P accumulated 1.9-19 g P kg-1. Nitrogen in wastewater was scarcely removed by the alkaline filter materials, but transformation from NH4-N to NO3-N was >90%. Pot experiments with barley (Hordeum vulgare L.) revealed that after wastewater treatment, slags and Polonite could increase plant production. Batch experi-ments and ATR-FTIR investigations indicated that amorphous tricalcium phosphate (ATCP) was formed in the materials, so some of the accumulated PO4-P was readily available to plants. Low heavy metal contents occurred in the materials, showing that they can be applied as soil amend-ments in agriculture without contamination risks. A full-scale treatment system using Polonite as filter material showed an average PO4-P removal efficiency of 89% for a 92-week period, indicat-ing the robustness of the filter bed technology.QC 20100907
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Briers, Hannah Katherine. "The design and optimisation of a novel filter device for the removal of nitrogen form wastewater." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535109.
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Ryan, Patrick. "REDUCING EFFLUENT PHOSPHORUS AND NITROGEN CONCENTRATIONS FROM A STORMWATER DETENTION POND USING A CHAMBER UPFLOW FILTER AND SKIM." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4307.
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Stormwater runoff is a known pollutant source capable of causing surface water degradation, especially in highly populated areas such as Central Florida. Wet detention ponds manage this stormwater, but most of the ponds do not remove enough nutrients, specifically nitrogen and phosphorus, to meet TMDL regulations. This research provides a possible addition to a detention pond in Seminole County, Florida using a Chamber Upflow Filter and Skimmer (CUFS), which can increase the removal of phosphorus and nitrogen by the system. Water enters the system through the skimmer, which floats on the surface of the detention pond. It travels from the skimmer to the bottom of the chamber, where heavier particles settle out before entering the upflow filter. The upflow filter contains twenty-four inches of Black and GoldTM media to remove nitrogen and phosphorus under anoxic conditions. Water flows up through the filter and out of the system, and eventually travels to Lake Jesup, a eutrophic lake. A total of twenty-eight storm events and seven baseflows were sampled from the site in Seminole County, and ten storm events were sampled from a pilot study CUFS. The results of this research show significant reductions by the Seminole County CUFS in turbidity, orthophosphorus, total phosphorus, and total suspended solids when the means were compared at a 95% confidence interval. Reductions also occurred for total nitrogen, but could not be proved by the mean comparison. The pilot scale application of the CUFS significantly reduced total nitrogen at a 95% confidence interval.M.S.Env.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Environmental Engr MSEnvE
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Devience, Stephen J. "Nuclear Magnetic Resonance with Spin Singlet States and Nitrogen Vacancy Centers in Diamond." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11628.
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Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are techniques widely utilized by many scientific fields, but their applications are often limited by short spin relaxation times and low sensitivity. This thesis explores two novel forms of NMR addressing these issues: nuclear spin singlet states for extending spin polarization lifetime and nitrogen-vacancy centers for sensing small samples.Chemistry and Chemical Biology
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Janík, Prokop. "Redukce NOx obsažených ve spalinách." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230288.
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Research in the field of NOX abatement has grown significantly in the past two decades. The general trend has been to develop new catalysts with complex materials in order to meet the stringent environmental regulations. The master’s thesis deals with the cleaning flue gases through a filter element which is from porous ceramics. There is catalyst implemented for NOx reduction throug the method of selective catalytic reduction in the filter element. There is also description of experimental unit for flue gas cleaning. Part of the thesis is creation of prediction model which allows to predict efficiency reduction in the filtration device operating conditions with some accuracy.
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Hanák, Libor. "Zneškodňování spalin znečištěných NOx." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228697.
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There is an overview of secondary methods for NOX removal from stationary sources in the first part of master’s thesis. There are well known methods as SCR o SNCR, but also new and experimental ones. An accent is putting on catalytic filtration, especially on cloth filter, which will be used for experiments. An important part of master’s thesis is a project of new experimental unit for experiments with cloth and ceramic catalytic filters as well as with a bit of cloth filtration material. Unit has compact proportions, high-class measurement and control and wide application spectra. Other advantages of this equipment are fast and easy cleaning and installation. This unit, called INTEQ II, can be used in plants or in laboratories. There is prediction model created together with new technology. It enables calculation of efficiency at catalytic filters with variable conditions without many experiments. This model is elaborate and will be finished with dates from measuring. There in only summary of planned experiments in this thesis, because measurements at new unit have not done yet. Experiences with operations at unit INTEQ I were used for proposal of new equipment and for experiments planning.
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Rumánek, Tomáš. "Redukce NOx ve spalinách." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229280.
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My master´s thesis deals with the problems of NOx abatement that are included in flue gas. The accent is put on flue gases treatment throug cloth filter or ceramic candles, where the deposited catalyst enables NOx reduction throug the method of selective cytalytic reduction. In thesis is also describe experimental unit which current remove gaseous pollutants (dioxin, VOC and NOX) and ash on catalytic cloth filter or catalytic ceramic candles. For experimental unit has been calculated pressure drop. Pressure drop has been calculated for nominal and maximal conditions for cloth filter and ceramic candle. Last part of thesis deals with compile a experimental schemes for different concentration of NO, flow and temperature of combustion.
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Júnior, Humberto Carlos Ruggeri. "Pós-tratamento de efluente de lagoa facultativa visando à remoção de nitrogênio amoniacal." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-19072011-103911/.
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Discute o pós-tratamento de efluente de lagoas facultativas visando à remoção de nitrogênio amoniacal. Para isso, foram utilizadas unidades terciárias em escala piloto. A escolha do tipo de unidades para o pós-tratamento do efluente levou em consideração a questão do baixo custo e simplicidade de operação. Desta forma, para o estudo, fez-se opção por lagoas rasas e filtros percoladores como unidades de pós-tratamento. O objetivo principal do trabalho foi associar as taxas de aplicação superficial e volumétricas com as remoções de nitrogênio amoniacal nessas unidades. Para lagoas em escala piloto, foram adotadas profundidades de 0,5 m e 1,0 m. As lagoas rasas foram submetidas a diferentes taxas de aplicação e TDH. Para os filtros percoladores, foram escolhidos dois materiais diferentes como meio suporte, pedra britada e anel plástico. Os filtros foram submetidos a diferentes condições operacionais. Para os dois tipos de unidades complementares de tratamento, foram verificados os efeitos das condições ambientais sobre as eficiências de remoção. Na lagoa de 0,5 m foram observadas concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L para tempos de detenção de 5 dias e taxas de aplicação superficial de 50 kgDBO/ha.d. Na lagoa de 1,0 m, concentrações de nitrogênio amoniacal abaixo de 20 mg-N/L só foram possíveis com taxas de aplicação de 50 kgDBO/ha.d e TDH de 10 dias. A lagoa de 0,5 m apresentou uma eficiência maior na remoção de nitrogênio amoniacal do que a lagoa de 1,0 m. Os efluentes dos filtros apresentaram concentrações de nitrogênio amoniacal acima de 20 mg-N/L com taxas acima de 0,20 kgDBO/m³.d. Para taxas de aplicação hidráulica acima de 18 m³/m².d e 0,70 kgDBO/m².d houve o encerramento do processo de nitrificação nos filtros. Os valores de pH e as concentrações de NH3 no efluente da lagoa facultativa submeteram os filtros a operar dentro da faixa de inibição da nitratação, devido ao NH3, sendo observadas concentrações significativas de nitrito no seu efluente. Os filtros percoladores não foram adequados como unidades de pós-tratamento de efluente de lagoa. Embora as lagoas rasas não tenham atendido aos aspectos de múltiplas qualidades do efluente, elas foram mais adequadas ao pós-tratamento de efluente de lagoa facultativa do que os filtros percoladores.This study discusses the post treatment of effluent ponds aiming at removing the ammonia nitrogen. To this end, tertiary units were used in a pilot scale. The choice of units for the post treatment of the effluent took into consideration the issue of low cost and simplicity of operation. Thus, for this study, we chose shallow ponds and trickling filters as post-treatment units. The main objective of this study was to associate the superficial and the volumetric application rates with the removal of ammonia nitrogen of these units. For the ponds on a pilot scale, two depths were adopted: a pond of 0.5 m and another one of 1.0 m depth. The shallow ponds were subjected to different loading rates and HRT. For the trickling filters, two different kinds of materials were chosen as a medium support: crushed stone and plastic ring. The filters were also subjected to different operating conditions. For both types of additional treatment units it was observed the effects of the environmental conditions on the removal efficiencies. In the pond of 0.5 m depth, it was observed concentrations of ammonia nitrogen below 20 mg-N/L for detention times of 5 days and superficial application rates of 50 kgBOD/ha.d. In the pond of 1.0 m depth, concentrations of ammonia nitrogen below 20 mg-N/L were only possible with application rates of 50 kgBOD/ha.d and HRT of 10 days. The 0.5m-depth pond showed a better efficiency in the removal of ammonia nitrogen than then1.0m-depth pond. The filters had concentrations above 20mg-N/L with rates above 0.20 kgBOD/m³.d. For hydraulic application rates above 18m³/m².d and 0.70kgBOD/m².d there was the cessation of the nitrification process in the filters. The pH values and the concentrations of NH3 in the effluent of the facultative pond made the filters operate within the range of inhibition of nitration, due to the NH3, and it was observed significant concentrations of nitrite in the effluent of the filters. The trickling filters were not suitable as units of post-treatment pond effluent. Although the shallow ponds have not met the multiple aspects of quality of the effluent, they were more adequately for facultative pond effluents post-treatment than trickling filters.
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Roupec, Ladislav. "Studie rekonstrukce kořenové čistírny pro obec Dražovice." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265382.
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The constructed wetlands, which have been being created in the Czech Republic since early 90s, are designed so they do not allow successful removal of ammonia nitrogen. Almost all of these 300 registered constructed wetlands suffer from the colmatage which leads to the lowest effectiveness of treatment in nearly all parameters. The main effort of the Institute of landscape water management is to get rid of bad reputation and to clarify the reason that leads to unsatisfactory conditions of constructed wetlands. The diploma thesis focuses on the selected constructed wetland in Dražovice (850 EO), which removes ammonia nitrogen with the effect just below the limit values in the long term. The pressure of the Morava river basin and Department of environment (Building Authority in Bučovice) has led to the necessity of taking measures leading to the increase of treatment efficiency especially ammonia nitrogen. The diploma thesis includes both, actual project documentation concentrating on the adjustment of watercourse to nitrify ammonia nitrogen, and effective choice of suitable filtration material supported by testing method in situ. The practical part of the thesis deals with the implementation of the technical solution according to the project documentation. The adjustment of the constructed wetland is now nearly before completion. Last adjustments will be taking place during the spring 2017, the final inspection as well as the evaluation of the reconstruction will take place at the end of this year.
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Franz, Rudolf. "Výzkum progresivních metod snižování obsahu škodlivých látek ve výfukových plynech vznětových motorů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-418061.
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The scope of this dissertation work is a description of modern methods of reducing exhaust emission in diesel engines. The fundamental part is the application of these methods for diesel engines for off-road use that means for engines that are used in tractors and road machines. The mentioned evidence for the practical utility of the results of this dissertation thesis in practice and their verification on the actual engine are given in the conclusion.
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Chui, Peng-Cheong. "STUDY ON ORGANICS AND NITROGEN REMOVAL USING SUBMERGED FIXED-BED FILTERS." Kyoto University, 1999. http://hdl.handle.net/2433/181847.
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Millot, Yoann. "Use of alternative matrix materials and configurations for optimizing nitrogen removal in constructed wetlands." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI021/document.
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L’assainissement d’effluents résiduaires urbains par filtres plantés de roseaux (FPR) rencontre, depuis plus de trois décennies, un engouement croissant en raison de ses remarquables performances de traitement ainsi que de considérations technico-économiques et écologiques. Néanmoins, des objectifs de traitement de plus en plus contraignants, ainsi qu’un marché de plus en plus concurrentiel, amènent la nécessité d’une meilleure connaissance des processus afin d’en optimiser la conception en fonction du contexte. Une attention toute particulière a été portée au traitement de l’azote, au cours de cette étude, en raison de l’aspect particulièrement contraignant de son élimination. Ces travaux se sont articulés autour de trois axes principaux permettant l’évaluation des principaux mécanismes d’élimination de l’azote (nitrification, dénitrification et adsorption, respectivement). Un premier volet, conduit sur unités pilotes alimentées en effluents domestiques réels, s’est attaché à identifier l’impact respectif de divers critères de dimensionnement et opérationnels (profondeur de filtration, surface de filtration, charges hydrauliques et organiques) afin de proposer des consignes de conception adaptées aux objectifs de traitement sur l’azote ammoniacal ainsi que la matière organique et la pollution particulaire. Une seconde partie de l’étude, mené à échelle pilote à partir d’effluents semi-synthétiques, s’est quant à elle focalisée sur le processus de dénitrification afin de mettre en exergue les critères majeurs (composition des effluents, paramètres de conception et fonctionnement) pour l’atteinte de performances poussées sur le traitement des nitrates. Enfin, un dernier axe de recherche, effectué en laboratoire en colonne, a visé à évaluer l’effet de l’adsorption d’ammonium sur matériaux filtrants réactifs (zéolithe) en vue d’optimiser par la suite le temps de rétention de cette espèce au regard des cinétiques de dégradation biologique. Une synthèse des connaissances acquises au cours de cette étude a donné lieu à des conseils de conception ainsi qu’à des recommandations pour d’éventuelles études complémentairesThe treatment of domestic wastewater by constructed wetlands (CWs) meets, from more than three decades, an increasing interest because of its high treatment efficiency as well as technological, economic and ecological issues. However, with treatment objectives that are growing ever stricter and an increasingly competitive market, fine knowledge of removal processes is required in order to optimize design in regards with context. A particular attention was paid to nitrogen removal, through this study, because of its particularly coercive dimension in treatment process. This work is partitioned in three axes which enable the assessment of the main mechanisms ensuring nitrogen removal (nitrification, denitrification and sorption, respectively). A first part, conducted in pilot-scaled units fed in real domestic wastewater, aimed at identifying the respective effects of various design and operational parameters (filtration height, filtration area, hydraulic and organic loads) in order to provide design recommendations for an efficient removal of ammonium as well as organic matter and suspended solids. A second part of this work, carried out in pilot-scaled units fed with semi-synthetic wastewater, focused on denitrification process in order to highlight driving parameters (influent composition, design and operational parameters) of full nitrate removal. Last but not least, a third research axis, conducted in column-scaled units, assessed the ammonium adsorption onto reactive material (i.e. zeolite) in order to optimize the retention time of ammonium within the system in regards with nitrification kinetic. These results were then summarized in order to provide design guidelines as well as recommend further complementary experiments
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Kietliñska, Agnieszka. "Engineered Wetlands and Reactive Bed Filters for Treatment of Landfill Leachate." Licentiate thesis, KTH, Land and Water Resources Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1693.
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The main objectives of this study were to investigate (i) anovel wetland treatment technology and (ii) selected bed filtermedia for the removal of contaminants from landfill leachate. Areview of the literature concerning experiences of the use ofconstructed wetlands (CW) for the removal of nitrogen fromlandfill leachate, showed that at least three groups oftreatment systems are in practice: sub-surface flow wetlands,hybrid systems (a combination of vertical and horizontal flowwetlands) and, compact constructed wetland (CCW). Most of thesetypeswere generally effective in reducing nitrogen (N,e.g.NH4-N, dominant N species in leachate) down toeffluent concentrations of about 10 mg L-1. Unfortunately, very little evidence ofresponsible mechanisms for the removal of N was presented,although some data indicated denitrification. The treatmentperformance of a compact constructed wetland (CCW) applied atthe Tveta Landfill, Södertälje, Sweden, wasevaluated. Chemically purified leachate and untreated leachatewere applied in periods of 7 day submergence and 7 day drainageto different sections of the CCW. The removal efficiency variedbetween 40 and 82%, and a mass removal rate of up to 5.1 g m2d-1was achieved. The chemical pre-treatment had adecisive role for the highest removal efficiencies obtained andit was unclear whether that treatment enhanced the efficiencybecause of lower toxicity and/or content of fewer competingcations. The possible combination of bed filter media and CCWas an ecotechnological treatment method for landfill leachatewas investigated by bench-scale laboratory column experiments.Reactive filter media (sorbents) was selected from their knownor suggested capacities for removal of heavy metals, nitrogenand phosphorus. Quartz sand or natural sand from an esker wasused as reference medium. Peat was used as an additionalcomponent in mixtures with the reactive media Polonite®(product from the bedrock opoka) and blastfurnace slag (BFS). A small column study also involved zeolite.Phosphorus was efficiently removed by Polonite®and NH4-N to some extent. Concerning metal removal, thebest performance was found as well for Polonite®, especially for Mn, Fe, Zn and Cu. The BFSshowed good removal efficiency for Cu, Ni and Mo. The removalof different elements was suggested to be a combination ofseveral factors,e.g.precipitation, ion exchange and adsorption. Priorto full-scale application of reactive filters at a landfillsite, matrix selection, filter design and operationalprocedures must be developed.
Keywords:Blast furnace slag; Compact constructedwetland; Metals; Nitrogen; Polonite; Sorbents
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Hamden, Rafidah Binti. "Aerated blast furnace slag filters for enhanced nitrogen and phosphorus removal form small wastewater treatment plants." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.535097.
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Pang, Haoran. "Etude de l'hydrodynamique, de l'élimination de la DCO et de la nitrification d'un nouveau lit bactérien segmenté." Thesis, Toulouse, INSA, 2014. http://www.theses.fr/2014ISAT0003/document.
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L'objectif principal de ce travail de thèse concerne l'étude de l' élimination de la DCO et de la nitrification dans une nouveau lit bactérien Multi-Section ( MSB ) . Après une caractérisation de l’hydrodynamique et du transfert d’oxygène de ce lit bactérien, les expériences biologiques menées sous des conditions opératoires contrastées (fortes et faibles charges organiques eteaux usées contenant ou pas des matières particulairs) ont été menées. En parallèle, des simulations avec le logiciel Biowin® ont été réalisées. Les principaux résultats sont résumés en suivant :- La rétention de liquide statique est majoritaire par rapport à la rétention dynamique que ce soit en présence ou en absence de biofilm. Le biofilm joue le rôle d’une "éponge" permettant un maintien de l’humidité du lit même à faible débit. Les expériences de DTS ont montré que le biofilm accroit le temps de séjour du liquide et conduit à une diminution de l’épaisseur du film liquide permettant ainsi de promouvoir le transfert de l'oxygène.- Le réacteur MSB montre une élimination efficace de la DCO (> 95 % ) et de la nitrification ( > 60 % de l’azote entrant), mais une accumulation de DCO particulaire a lieu dans le filtre ce qui conduira à un colmatage à terme. La nitrification cohabite avecl’élimination de la DCO même dans la première section et pour une charge organique élevée ce qui implique une bonne capacité d’oxygénation du MSB par l’aération naturelle.- Un modèle dynamique de MSB a été utilisé implémenté sur le simulateur - BioWin , afin d'obtenir la répartition des biomasses au sein du réacteur et d'évaluer le processus limitant dans chaque section. Le modèle partiellement calibré peut aider à estimer les besoins minimum d'oxygène pour la nitrification et peut rendre compte de la compétition entre la croissance hétérotrophe et la nitrificationThe main objective of this PhD work focused on the study of the COD removal and nitrification in a new designed Multi-Section Bioreactor (MSB). Hydrodynamic characterization of the reactor, biological experiments under contrasted conditions and simulations by Biowin® software were carried out:- Firstly, it was found that static liquid retention is the predominant part both without and with the presence of biofilm. Biofilm acts like a "sponge". RTD experiments showed that biofilm can promote liquid residence time, decrease the liquid film andpromote the oxygen transfer consequently.- Secondly, the MSB operated at contrasted organic loading rate (OLRs) and nitrogen loading rate (NLRs) showed that COD can be effectively removed (removal efficiency > 95%) and nitrification (> 60% of the N removal) occurred in this biofilter.Nitrification is efficient even in the first section implying no drastic oxygen limitation though only natural aeration is occurring.- Thirdly, a TF dynamic model has been used from a simulator - BioWin, in order to get more insights on the biomass distribution in the pilot and to assess the limiting process in each section of the bioreactor. Calibration of the model can help us to estimate theminimum oxygen requirement for nitrification for each zone inside the pilot and it can well represent the competition between heterotrophic growth and nitrification
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Shamir, Eylon. "Nitrogen Accumulation In A Constructed Wetland For Dairy Wastewater Treatment." Thesis, The University of Arizona, 1998. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0014_m_sip1_w.pdf&type=application/pdf.
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Okubo, Hitoshi, Masahiro Hanai, Naoki Hayakawa, Hiroki Kojima, and Diaa-Eldin A. Mansour. "Physical Mechanisms of Partial Discharges at Nitrogen Filled Delamination in Epoxy Cast Resin Power Apparatus." IEEE, 2013. http://hdl.handle.net/2237/20739.
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Burkhart, John F. "Variability of nitrogen deposition and preservation over the Greenland Ice Sheet." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1069%5F1%5Fm.pdf&type=application/pdf.
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Correa, Washington Luiz Alves. "Contribuição para a sintese de diamante com dopagens de boro, nitrogenio ou enxofre." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260578.
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Orientador: Vitor BaranauskasTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Estudamos processos de dopagem do diamante crescido por deposição química a partir da fase vapor (diamante CVD) com a introdução de impurezas dopantes durante o crescimento do diamante em reatores do tipo filamento-quente. Focalizamos nossa pesquisa na dopagem do diamante com boro, ou nitrogênio, ou enxofre, visando obter diamantes com propriedades semicondutoras com condutividade eletrônica (tipo n) ou condutividade por lacunas (tipo p). Foram utilizadas contaminações intencionais utilizando: trimetil borano (B(CH3)3), ou amônia (NH3), ou dissulfeto de carbono (CS2), misturados com metano e diluídos em hidrogênio. As amostras foram caracterizadas por microscopia eletrônica de varredura (SEM), espectroscopia Raman, espectroscopia de foto-elétrons excitados por raios X (XPS), espectroscopia de emissão de raios X excitado por feixe de prótons (PIXE) e efeito Hall. As dopagens do diamante do tipo p e do tipo n foram obtidas com contaminações de boro e enxofre, respectivamente. O diamante dopado com nitrogênio não apresentou propriedades semicondutoras
Abstract: We studied the diamond doping processes with introduction of doping impurities during the diamond growth in the chemical vapor deposition (CVD) technique, using a hot-filament reactor. Our research focused the use of boron, nitrogen or sulphur atoms in order to obtain diamond films with semiconductor properties of electronic (n-type) or hole (p-type) current transport mechanisms. Trimethyl-borane (B(CH3)3), or ammonia, or carbon disulphide (CS2), mixed with methane and hydrogen were used in the feed gas mixture. The diamond samples were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Proton-induced X-ray emission (PIXE) and Hall effect. p-type and n-type diamonds have been obtained with boron and sulphur doping, respectively. However, the nitrogen doped samples do not presented semiconductor properties
Doutorado
Engenharia de Eletronica e Comunicações
Doutor em Engenharia Elétrica
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Diniz, José Alexandre 1964. "Formação de filmes finos de oxinitreto de silicio (SiOxNy) por implantação de ions de nitrogenio (N2+) e de oxido nitrico (NO+)." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260463.
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Orientador: Peter Jurgen TatschTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica
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Resumo: Este trabalho descreve a obtenção e a caracterização de filmes finos e ultra-finos de oxinitreto de silício (SiOxNy)através da implantação de íons moleculares de nitrogênio (N2) e de óxido nítrico (NO+) com baixa energia em óxidos de silício crescidos termicamente sobre substratos de silício ou em substratos de silício com posterior oxidação térmica... Observação: O resumo na integra, poderá ser visualizado no texto completo da tese digital
Abstract: This work describes the formation and the characterization of ultra-thin and thin silicon oxynitride (SiOxNy) films by low-energy molecular nitrogen (N/) or nitric oxide (NO+) ion implantation in thermal silicon oxide (SiO2) grown on silicon substrate or into silicon substrate prior to thermal oxidation... Note: The complete abstract is available with the full electronic digital thesis or dissertations
Doutorado
Doutor em Engenharia Elétrica
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Champi, Farfan Ana Melva. "Estudo das propriedades termomecânicas e estruturais de filmes finos amorfos de carbono e nitretos de carbono." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/277838.
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Orientador: Francisco das Chagas MarquesTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
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Resumo: Nesta tese estudamos a influência da incorporação de nitrogênio nas propriedades termomecânicas e estruturais em matrizes de carbono amorfo hidrogenado (a-C:H) e não hidrogenado (a-C). Duas técnicas de deposição foram utilizadas para o crescimento dos filmes. Os filmes hidrogenados foram preparados utilizando um sistema de glow discharge e as não hidrogenadas foram preparadas por IBAD. Um estudo preliminar foi feito em função do bias e a pressão do metano CH4, com o objetivo de escolher duas condições para a incorporação de nitrogênio. Deste primeiro estudo foi observado um aumento do coeficiente de dilatação térnica dos filmes de a-C:H com o aumento das ligações sp2. A partir desta série, uma segunda série de amostras com matriz tipo diamond-like e graphite-like de a-C:H foram estudadas, nas quais observamos que independente da matriz, a incorporação de nitrogênio produz um aumento no coeficiente de dilatação térnica (CTE) de até 9x10-6 C-1 para cerca de 6% de nitrogênio, próximo do valor do CTE do grafite (8x10-6C-1). A influência do nitrogênio no carbono amorfo aumenta a geração das hibridizações sp e sp2, o qual facilita a fornação de clusters grafíticos dentro dos filmes de a-C:H:Nx. O empilhamento dos clusters e a influência destes no CTE dos filmes são amplamente discutidos, para o qual técnicas espectroscópicas como Raman, infravermelho e perda de energia dos elétrons (EELS) são estudadas nesta tese. Por outro lado, para ter uma visão mais clara da influência do N, amostras com matrizes não hidrogenadas de a-C foram preparadas pela técnica de IBAD. Com nesta técnica temos filmes de a-C:Nx com altas concentrações de nitrogênio (até ~30%). Foi observado que mesmo com altas concentrações de N, o CTE dos filmes de a-C:Nx não consegue atingir valores acima de 5xl0-6 C-1. Este fato, faz pensar que o hidrogênio cumpre um papel muito importante no ernpilhamento dos clusters grafíticos. A partir das medidas feitas pela técnica de TIB (o qual foi desenvolvido em nosso laboratório e utilizado para medir o stress, CTE e módulo biaxial dos filmes) e a Nanoindentação obtivemos separadamente o módulo de Young (E) e a razão de Poisson (v), nas três séries de amostras estudadas. Os resultados são discutidos como uma função dos tipos de hibridizações dos filmes de a-C:H, a-C:H:Nx e a-C:Nx
Abstract: In this work, we studied thenno mechanical and structural properties of hydrogenated amorphous carbon (a-C: H), hydrogenated carbon nitride (a-C:H:Nx) and carbon nitride (a-C:Nx) thin films. Two techniques were used to prepare the samples: glow discharge for depositing hydrogenated amorphous carbon (a-C:H) and carbon nitride (a-C:H:Nx) and ion beam assisting deposition (IBAD) for unhydrogenated amorphous carbon nitride (a-C:Nx) films. The curvature of the film/substrate composites was measured using the thermally induced bending (TIB) technique in order to determine the stress of the films. By varying the temperature and using films deposited in several different substrates one was able to obtain the coefficient of thermal expansion (CTE) and the biaxial modulus (E/(l-v)) of the films. Complementarily to this technique, we perfonned nanohardness measurements, which also allows to obtaining the elastic constant (E/(1-v2)) as well. Using both techniques, TIB and nanohardness, we determined, for the first time, separately the Young's modulus (E) and the Poisson's ratio (v) of a-C:H, a-C:H:Nx and a-C:Nx. These thermomechanical properties were investigated as a function of sp2-bond, or graphite's cluster, concentrations, using the following techniques: EELS, infrared spectroscopy, visible and ultraviolet Raman spectroscopy. The influence of the incorporation of nitrogen in the hydrogenated and unhydrogenated matrixes is discussed. We observed that the CTE of a-C:H depends strongly on the concentration of Sp2 sites approaching the value for graphite as the concentration tends to 100 %. The nitrogen incorporation increases the cluster formation in matrixes, inducing a substantial increase of the CTE of the fi1ms. On the other hand, in the matrix free of hydrogen it was observed that the CTE is not strongly influenced by the nitrogen concentration. These observations indicate that hydrogen plays an important role on the value of the CTE in amorphous carbon nitrogen films
Doutorado
Física da Matéria Condensada
Doutor em Ciências
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Adler, Anneli. "Accumulation of elements in Salix and other species used in vegetation filters with focus on wood fuel quality /." Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200706.pdf.
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Bueno, Jomar Esteves [UNESP]. "Caracterização do diamante CVD depositado sob atmosfera com adição de baixa concentração de N2." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/97113.
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Sendo um importante e emergente ramo dentro da área dos novos materiais, a deposição de filmes de diamante CVD tem despertado cada vez mais interesse na comunidade científica internacional. O propósito principal dessa dissertação é contribuir com os trabalhos de pesquisa sobre deposição de filmes de diamante CVD, assistidos por filamento quente. O desenvolvimento dos experimentos ocorreu utilizando-se amostras com substratos de Si, sobre as quais foram depositados diamante CVD, com adição de baixa concentração de N2 à mistura gasosa precursora. Optou-se pela baixa concentração, sendo esta uma condição desafiadora, com poucas informações disponíveis. As amostras resultantes dos experimentos foram caracterizadas através do MEV, DRX e EDX revelando, respectivamente uma morfologia com mesmo tamanho e formato dos cristais, confirmando ainda a presença de filme de diamante CVD, cujos cristais apresentaram dimensões uniformes e o filme formado teve cobertura de toda amostra. Assim verificou-se que com a adição de 0,75% em volume de N2 houve a deposição de diamante CVD de alta pureza cristalina, ou seja, de alta qualidade.
As an important and emergent material the CVD diamond has got the attention of the international scientific communities. This study is aimed at continuing the research about CVD diamond using a hot-filament reactor, analyzing its potential and possibilities of its technological applications. The development of the experiments were done on Si substrate samples and the growth process was studied with the introduction of small concentration of N2 in the feed gas mixture, during the diamond growth, in the hot-filament reactor by the chemical vapor deposition technique. The decision to choose a small concentration of N2 was taken because there are few papers and published results. The diamond samples were characterized by scanning electron microscopy and X-ray to verify the properties of the sample and also its morphology. The diamond growth in the nitrogen atmosphere resulted in crystals and thin films with similar morphology and dimensions. Therefore, by the characterization techniques it was verified that the addition of 0,75% in volume of N2 has resulted in a high crystalline purity CVD diamond deposition.
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Felicio, Alexandre Gorni. "Filmes isolantes de SiOxNy formados por implantação de nitrogenio em substrato de silicio e posterior oxidação termica." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259173.
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Orientador: Jose Alexandre DinizDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e Computação
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Resumo: Este trabalho descreve a obtenção e a caracterização de filmes finos e ultra-finos de oxinitreto de silício (SiOxNy)através de implantação de íons moleculares de nitrogênio (N2+) com baixa energia em substrato de silício com posterior oxidação térmica. Os filmes foram caracterizados por elipsometria (espessura), por espectrometria de absorção do infta-vermelho (FTIR) (ligações químicas) e por espectrometria de massa do íon secundário (SIMS) (distribuição de nitrogênio). Estes filmes foram utilizados como isolantes de porta de transistores nMOSFETs e capacitores MOS. Caracteristicas elétricas como mobilidade entre 390 cm ² /Vs a 530 cm²/vs, e inclinação (slope) na região de sub-limiar entre 7OmV/dec e 15OmV/dec foram obtidas nos nMOSFETs. Nos capacitores MOS foram feitas medidas de capacitância x tensão (C-V) (espessura) e de corrente x tensão (corrente de fuga). Através das curvas C-v foram obtidas espessuras equivalentes (EOT) entre 2.9nm e 15.7nm. Os filmes de oxinitreto com EOT entre 2.9 cm 4.3 cm apresentaram densidades de corrente de fuga entre 4.5mA/cm² e 50nA/cm²
Abstract: This work describes the formation and the characterization of ultra-thin and thin silicon oxynitride (SiOxNy)films by low-energy molecular nitrogen (N21 into silicon substrate prior to thermal oxidation. The films were characterized by ellipsometry (thiclmess), infta-red absorption spectrometry (FTIR) (chemical bonds) and secondary ion mass spectrometry (SIMS) (nitrogen distribution). These films have been used as gate insulators in nMOSFETs and MOS capacitors. NMOSFET electrical characteristics, such as field effect mobility between 390 cm²/Vs and 530 cm² /Vs, and sub-threshold slope between 70 mV/decade and 150 mV/decade, were obtained. MOS capacitors were used to obtain capacitance-voltage (C-V) and current-voltage (I-V) measurements. The Equivalent Oxide Thickness (EOT) ofthe films were obtained ftom C-V curves, resulting in values between 2.9nm and 15.7nm. SiOxNygate insulators with EOT between 2.9nm and 4.3nm have presented gate leakage current densities between 4,5mA/cm² and 50nA/cm²
Mestrado
Eletrônica, Microeletrônica e Optoeletrônica
Mestre em Engenharia Elétrica
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Dickey, Juliana Sloan. "The effects of selected nitrogen and sulfur applications on soil pH, water soluble sulfate, DTPA extractable iron, manganese, copper and zinc on selected Arizona soils." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_190_sip1_w.pdf&type=application/pdf.
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Bueno, Jomar Esteves. "Caracterização do diamante CVD depositado sob atmosfera com adição de baixa concentração de N2 /." Guaratinguetá : [s.n.], 2007. http://hdl.handle.net/11449/97113.
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Orientador: Teófilo Miguel de SouzaBanca: Samuel Euzedice de Lucena
Banca: Osiris Cancigleri Júnior
Resumo: Sendo um importante e emergente ramo dentro da área dos novos materiais, a deposição de filmes de diamante CVD tem despertado cada vez mais interesse na comunidade científica internacional. O propósito principal dessa dissertação é contribuir com os trabalhos de pesquisa sobre deposição de filmes de diamante CVD, assistidos por filamento quente. O desenvolvimento dos experimentos ocorreu utilizando-se amostras com substratos de Si, sobre as quais foram depositados diamante CVD, com adição de baixa concentração de N2 à mistura gasosa precursora. Optou-se pela baixa concentração, sendo esta uma condição desafiadora, com poucas informações disponíveis. As amostras resultantes dos experimentos foram caracterizadas através do MEV, DRX e EDX revelando, respectivamente uma morfologia com mesmo tamanho e formato dos cristais, confirmando ainda a presença de filme de diamante CVD, cujos cristais apresentaram dimensões uniformes e o filme formado teve cobertura de toda amostra. Assim verificou-se que com a adição de 0,75% em volume de N2 houve a deposição de diamante CVD de alta pureza cristalina, ou seja, de alta qualidade.
Abstract: As an important and emergent material the CVD diamond has got the attention of the international scientific communities. This study is aimed at continuing the research about CVD diamond using a hot-filament reactor, analyzing its potential and possibilities of its technological applications. The development of the experiments were done on Si substrate samples and the growth process was studied with the introduction of small concentration of N2 in the feed gas mixture, during the diamond growth, in the hot-filament reactor by the chemical vapor deposition technique. The decision to choose a small concentration of N2 was taken because there are few papers and published results. The diamond samples were characterized by scanning electron microscopy and X-ray to verify the properties of the sample and also its morphology. The diamond growth in the nitrogen atmosphere resulted in crystals and thin films with similar morphology and dimensions. Therefore, by the characterization techniques it was verified that the addition of 0,75% in volume of N2 has resulted in a high crystalline purity CVD diamond deposition.
Mestre
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Chaloupka, Ondřej. "Výzkum technologie vícestupňového filtračního systému kořenové čistírny." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391889.
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The ways of purifying waste water produced by human society are nowadays a great deal. With the increasing pressure on sustainable construction, technology using principles close to natural processes are at the forefront. Treatment wetlands have been in use for almost 30 years and thanks mainly to developments abroad, they prove they are a suitable option for smaller producers of pollution. When designing a treatment wetland for municipalities with a larger amount of inhabitants, it is necessary to modify the proposal in order to eliminate all types of pollution. This thesis therefore compares three sewage treatment plants with a multistage filtration system. Comparing the achieved parameters will be beneficial for defining the rules for optimal design of these types of wastewater treatment plant.
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Copetti, Gabriela. "Estabilidade de filmes de GeOxNy crescidos termicamente sobre Ge." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/131392.
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A instabilidade térmica do óxido de germânio (GeO2) é um obstáculo à utilização de germânio (Ge) como material semicondutor em dispositivos MOSFET. Essa instabilidade é induzida por vacâncias de oxigênio originadas de uma reação interfacial entre o óxido e o substrato. Essas vacâncias são responsáveis pela dessorção de GeO da superfície do óxido e pela deterioração das propriedades elétricas do transistor. Estudos sugerem que a incorporação de nitrogênio no GeO2 aumenta a sua estabilidade. Nesta dissertação, filmes de oxinitreto de germânio (GeOxNy) foram crescidos termicamente sobre Ge, utilizando gás óxido nítrico (NO), em um forno aquecido resistivamente. Técnicas de análise por feixe de íons, como espectrometria de retroespalhamento Rutherford e análise por reações nucleares, foram utilizadas para investigar o transporte atômico durante o crescimento dos filmes e o papel do nitrogênio na estabilização do óxido. Para a determinação da espessura, da densidade e da rugosidade de alguns filmes, foram realizadas medidas de reflectometria de raios X. Os resultados mostram que a incorporação de uma pequena quantidade de nitrogênio resulta em uma diminuição substancial na dessorção de GeO e na formação de uma barreira eficiente contra a oxidação adicional do substrato. Átomos de nitrogênio incorporados na estrutura do óxido podem reduzir a difusividade das vacâncias de oxigênio, levando ao aumento da estabilidade térmica.The thermal instability of germanium oxide (GeO2) hinders the use of germanium (Ge) as the semiconductor material in MOSFET devices. This instability is induced by oxygen vacancies originated from the interfacial reaction between the oxide and the substrate. These vacancies are responsible for GeO desorption from the oxide surface and deterioration of the device’s eletrical properties. Previous studies suggest that nitrogen incorporation increases the oxide’s stability. In this dissertation, germanium oxynitride (GeOxNy) films were thermally grown on Ge using nitric oxide (NO) gas, in a conventional resistively heated furnace. Ion beam analysis tecniques, such as Rutherford backscattering spectrometry and nuclear reaction analysis, were used to investigate atomic transport during thermal growth and the role of nitrogen in the improved stability. Film thickness, density and roughness were obtained through X-ray reflectometry. Results show that the incorporation of a small amount of nitrogen yields a substantial decrease in GeO desorption and the formation of a strong barrier against further oxidation of the substrate. Nitrogen atoms incorporated into the oxide structure may decrease oxygen vacancy diffusivity, leading to enhanced thermal stability.
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Salgado, Tania Denise Miskinis. "Estudo experimental de filmes ultrafinos de oxinitretos de silício por substituição isotópica e perfilometria com resolução subnanométrica." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 1999. http://hdl.handle.net/10183/9007.
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Traçagem isotópica foi usada para investigar o transporte atômico durante o crescimento térmico de filmes de oxinitreto de silício em lâminas de silício previamente implantadas com íons de nitrogênio a energias muito baixas, na faixa de 1/30 até 1 monocamada, e durante a etapa final de fabricação de filmes ultrafinos de óxido/nitreto/óxido sobre silício. Íons 15N+ a 20 eV foram implantados em substratos previamente limpos de Si (001) e oxidações térmicas foram realizadas em 18O2 seco. Deposição de nitrogênio foi também realizada sobre uma fina camada de 29Si, obtida por implantação a energia muito baixa em silício natural. As quantidades de nitrogênio e de oxigênio nos filmes foram determinadas por Análise por Reação Nuclear e os perfis de concentração de 15N, 18O e 29Si foram determinados com resolução sub-nanométrica por Perfilometria em Profundidade por Reações Nucleares com Ressonâncias Estreitas. Uma redução progressiva da taxa de oxidação com o aumento da densidade superficial de nitrogênio implantado foi observada. A traçagem isotópica mostrou os detalhes da redistribuição do nitrogênio, revelando que, durante o crescimento do filme, nitrogênio e oxigênio são responsáveis pelo transporte atômico, enquanto o silício permanece imóvel. Foi observado um novo mecanismo de crescimento do filme, não ativo no crescimento térmico de filmes de óxido de silício puro. As mesmas técnicas de análise foram usadas para estudar uma estrutura inicialmente “empilhada” Si/Si16O2/Si3 15N4, a qual foi oxidada termicamente em 18O2 seco, de modo a se investigar a influência do tempo e da temperatura de tratamento sobre as distribuições de 16O, 18O e 15N. Foi verificado que o tratamento térmico induziu transporte atômico e que a estrutura final não era “empilhada”, mas, sim, um filme ultrafino de oxinitreto de silício, de composição variável, que apresenta concentrações moderadas de nitrogênio nas regiões próximas à superfície e à interface e concentração de nitrogênio mais elevada no volume do filme.Isotopic tracing was used to investigate atomic transport during the thermal growth of silicon oxynitride films on silicon wafers implanted with very low energy nitrogen ions in the 1/30 to 1 monolayer range and during the final fabrication step of ultrathin silicon oxide/nitride/oxide films. 15N+ ions at 20 eV were implanted into previously cleaned Si (001) substrates and thermal oxidations were performed in dry 18O2. Nitrogen deposition was also performed on a thin 29Si layer obtained by low energy ion implantation on natural Si. The amounts of nitrogen and oxygen in the films were determined by Nuclear Reaction Analysis and the 15N, 18O, and 29Si concentration profiles were determined with sub-nanometric resolution by Narrow Nuclear Resonance Depth Profiling. A progressive reduction of oxidation rate with increasing areal density of implanted nitrogen was observed. Isotopic tracing showed the details of nitrogen redistribution in the films, revealing that only nitrogen and oxygen are mobile during growth, while silicon remains immobile. A new mechanism of film growth, not active in the thermal growth of pure silicon oxide films, was observed. The same techniques of analysis were used to study an initially stacked Si/Si16O2/Si3 15N4 structure which was thermally oxidized in dry 18O2, in order to investigate the influence of time and temperature of treatment on the profiles of 16O, 18O, and 15N. It was shown that thermal treatment promoted atomic transport and that the final structure is not a stacked one, but rather a silicon oxynitride ultrathin film with variable composition, presenting moderate concentrations of nitrogen in the near-surface and near-interface regions, and a higher nitrogen concentration in the bulk.
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Miotti, Leonardo. "Transporte atômico e incorporação de oxigênio em filmes de HfSiO e HfSiON depositados sobre Si." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2004. http://hdl.handle.net/10183/3785.
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Esse trabalho estuda a estabilidade térmica e o transporte atômico em filmes dielétricos de HfSiO e HfSiON depositados por sputtering reativo sobre c-Si. Esses materiais possuem alta constante dielétrica (high- ) e são candidatos a substituir o óxido de silício como dielétrico de porta em dispositivos do tipo transistor de efeito de campo metal-óxido-semicondutor (MOSFETs). Esses filmes foram submetidos a diferentes seqüências de tratamentos térmicos em atmosferas inerte e de O2, e foram caracterizados através de análises de feixe de íons e espectroscopia de fotoelétrons induzidos por raios-X (XPS). Nesse estudo foi observado que a incorporação de oxigênio se dá através da troca com N ou O previamente existente nos filmes. Em filmes de aproximadamente 50 nm de espessura foi observado que a presença do N limita a difusão de oxigênio de forma que a frente de incorporação avança em direção ao interior do filme com o aumento do tempo de tratamento, enquanto nos filmes de HfSiO/Si o oxigênio é incorporado ao longo de todo o filme, mesmo para o tempo mais curto de tratamento. Diferentemente de outros materiais high- estudados, não foi possível observar migração de Si do substrato em direção a superfície dos filmes de HfSiON/Si com aproximadamente 2,5 nm de espessura. Os resultados obtidos nesse trabalho mostram que filmes de HfSiON/Si são mais estáveis termicamente quando comparados com outros filmes dielétricos depositados sobre Si anteriormente estudados, mas antes que ele se torne o dielético de porta é ainda necessário que se controle a difusão de N em direção ao substrato como observado nesse trabalho.
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Kaufmann, Ivan Rodrigo. "Estabilização de filmes finos de óxido de germânio por incorporação de nitrogênio visando aplicações em nanoeletrônica." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/83676.
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De maneira a melhorar o desempenho de um Transistor de Efeito de Campo Metal-Óxido-Semicondutor (MOSFET), o germânio (Ge) é um forte candidato para substituir o silício (Si) como semicondutor, devido a sua alta mobilidade dos portadores de carga. Contudo, o filme de dióxido de germânio (GeO2) sobre Ge é solúvel em água e suas propriedades elétricas inferiores. Nesse sentido, a proposta desta dissertação de Mestrado é oxinitretar termicamente filmes de GeO2 em atmosfera de óxido nítrico (15NO), de maneira a melhorar as propriedades elétricas e físico-químicas dessas estruturas. Inicialmente, as amostras foram limpas quimicamente usando uma mistura de peróxido de hidrogênio (H2O2) e ácido clorídrico + água (HCl + H2O, 4:1). Os filmes de GeO2 foram crescidos termicamente sobre Ge usando atmosfera de oxigênio enriquecido 97% no isótopo de massa 18 (18O), com parâmetros na qual geraram um filme com espessura de ~5 nm. As oxinitretações foram realizadas em um forno térmico rápido com atmosfera de 15NO, nas temperaturas variando de 400-600°C, nos tempos de 1 a 5 minutos. O objetivo da oxinitretação foi criar um filme de oxinitreto de germânio (GeOxNy) com propriedades físico-químicas satisfatórias para a indústria de microeletrônica. Também foram realizados recozimentos térmicos em atmosfera inerte com objetivo de testar a estabilidade térmicas dos filmes de GeOxNy. Análise com Reação Nuclear (NRA) e Espectrometria de Retroespalhamento Rutherford em geometria de canalização (RBS-c) foram utilizadas para quantificar a quantidade total de oxigênio 18O e 16O, respectivamente. NRP também foi utilizada de modo a determinar o perfil de concentração em função da profundidade para as espécies de 18O e 15N. De modo a investigar a composição química das amostras, Espectroscopia de Fotoelétrons induzidos por raio-X (XPS) foi utilizada. Pelas análises por RBS e NRA do 18O, podemos observar que ocorre troca entre os isótopos de 18O e 16O para todas das temperaturas de oxinitretação. Este resultado corrobora com estudos recentes da literatura. Para as amostras oxinitretadas em 5 minutos a 500°C e todas as amostras oxinitretadas a 550°C e 600°C, ocorre troca isotópica completa. Observamos ainda por NRP que o 15N é incorporado mais superficialmente para as temperaturas de oxinitretação até 550°C. Resultados de XPS indicam formação maior de GeOxNy próximos da superfície das amostras e para temperaturas e/ou tempos maiores. Testes de estabilidade térmica indicam que a incorporação de nitrogênio mais próximo das superfície da amostra inibe a dessorção das espécies de GeO. As amostras que não foram oxinitretadas acabam dessorvendo quase por completo o filme de GeO2 quando realizados os recozimentos térmicos. Este efeito do nitrogênio incorporado próximo da superfície tem grande potencial para uso em camadas interfaciais entre semicondutor e dielétricos de porta.In order to improve the performance of Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET), germanium is a good candidate to replace silicon as semiconductor due to its higher charge carrier mobility. However, the germanium dioxide (GeO2) film over Ge is water soluble and produces poor electrical characteristics. In this way, this Master dissertation proposes thermal oxinitridation of the GeO2 films in nitric oxide (15NO) atmosphere in order to improve its electrical and physico-chemical characteristics. Samples were first cleaned using a mixture of hydrogen peroxide (H2O2) and hydrogen chloride + water (HCl + H2O, 4:1). GeO2 films were thermally grown on Ge using oxygen enriched in 97% in the isotope of mass 18, which generated ~5 nm thick film. Oxinitridation was performed in a rapid thermal furnace under 15NO atmosphere, at the 400-600°C temperature range, and 1-5 minutes time range. The goal was to form a germanium oxinitride film (GeOxNy) with physico-chemical properties that are satisfactory for microelectronics industry. We also performed thermal annealing in inert atmosphere to test the thermal stability of GeOxNy films. Nuclear Reaction Analysis (NRA) and Rutherford Backscattering Spectrometry in channeled geometry (RBS-c) were used to quantify the total amount of oxygen 18O and 16O, respectively. NRP was also performed to determine the 18O and 15N depth distribution. In order to investigate the chemical composition of the samples, X-ray Photoelectron Spectroscopy (XPS) was performed. RBS and NRA analysis showed isotopic exchange between 18O and 16O for all temperatures investigated. This result corroborates previous literature studies. Samples oxynitrided in 5 minutes at 500°C and all the samples oxinitrided at 550-600°C showed complete isotopic exchange. We also observed by NRP that nitrogen incorporation occurs more superficially until 550°C. XPS results indicate more formation of GeOxNy near the surface of the samples and for higher temperatures and/or time of oxinitredation. Thermal stability results indicated that the nitrogen incorporation near the sample surface inhibit the GeO desorption. On the other hand, samples that were not oxynitrided have almost all the GeO2 desorbed when thermal annealing is performed.
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Zedník, Ondřej. "Využití stavebních recyklátů pro čištění odpadních vod." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409741.
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The constantly tightening wastewater treatment legislation require high-quality runoff from small-scale producers of pollution who are typically represented by small municipalities up to 500 inhabitants or decentralized parts of larger municipalities. Small municipalities are faced with high investment-intensity associated with the acquisition of new wastewater treatment plant. After several years of development, today natural technologies of wastewater treatment are in competition with mechanical-biological treatment plants. Natural technologies can even achieve better results than popular biological treatment plants. However, natural technology does not eliminate the main investment limit connected with the acquisition of wastewater treatment plant. If there was cheaper solution connected with using alternative filter materials (in our case recycled construction and demolition waste), small municipalities could take constructed wetland without large subsides. At the same time, the use of recycled construction and demolition wastes will lead to benefits in the field of sustainable urban development and replacement of non-renewable materials. Despite these benefits, recycled aggregates have never been considered as alternative filter materials for natural wastewater treatment plants. For that reason, the aim of diploma thesis is to assess the possibility of applying recycled aggregates for wastewater treatment which will include evaluation of real trial operation.
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Prigent, Stephane. "Optimisation du traitement de l'azote et du phosphore des eaux usées domestiques adapté aux filtres plantés de roseaux." Phd thesis, Ecole des Mines de Nantes, 2012. http://tel.archives-ouvertes.fr/tel-00809593.
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Le rejet des nutriments (phosphates et nitrates) issues des eaux usées domestiques entraînent la dégradation des écosystèmes (74 % du territoire français concerné en 2006). Compte tenu de la situation, l'Etat français a promulgué la Loi sur l'Eau et les Milieux Aquatiques le 30décembre 2006 qui vise à atteindre le " bon état écologique des eaux et des milieux aquatiques " d'ici 2015. Cette notion bien que difficilement intégrable a généré des normes plus strictes pour les stations d'épuration en termes de rejet de nutriments vers le milieu récepteur (jusque 15 mg NTOT.L-1 et 2 mg PTOT.L-1). Depuis la fin des années 1990, la technologie des filtres plantés de roseaux (FPR) est de plus en plus employée(> 2500 unités en 2012) pour le traitement des eaux usées domestiques des petites collectivités inférieures à 2000 Equivalent-Habitants. Cependant, des limites de traitement existent sur les concentrations résiduelles en azote (rejet de 70-80 mg NTOT.L-1) et en phosphore (rejet> 10 mg PTOT.L-1), en vue de répondre à la réglementation future. Ce travail a eu pour objectif de mettre en oeuvre des améliorations telles que la recirculation sur un étage de traitement pour le traitement de l'azote d'une part et l'emploi de matériaux réactifs pour piéger le phosphore d'autre part. La démarche scientifique expérimentale déployée a consisté à suivre des pilotes sur site réel et en laboratoire pendant 2 années. Le suivi des performances épuratoires et hydrauliques a été réalisé au cours du temps. Pour l'azote, 2 FPR (2,5 m²) garnis de schiste expansé (Mayennite®) ont été alimentés en effluent brut. L'effet de la hauteur de saturation en eau dans la partie drainante ainsi que l'effet de la recirculation ont été étudiés. Les résultats obtenus ont montré : une couche saturée à 38 % (rapporté à la hauteur totale) et un ratio de recirculation de 100 % permettent une meilleure élimination de la matière particulaire-carbonée (Arrêté du22 juin 2007) et de l'azote (< 20 mg NTK.L-1 ; < 45 mgNTOT.L-1). Deux laitiers de four à arc électrique ont été sélectionnés pour le traitement du phosphore. Ceux-ci ont été mis en œuvre dans 5 colonnes (6 L) en laboratoire alimentées en effluent synthétique en phosphore puis secondaire et dans 4 filtres réactifs pilote (0,3 m² ; 34 L) à flux horizontal sous surfacique alimentés en effluent secondaire. Il ressort de ces expériences: (i) des disparités existent entre les deux échelles en termes de performances (< 2 mg P.L-1 pendant 20 mois en colonne et variation saisonnière des performances en pilote) et mécanismes épuratoires (adsorption/précipitation P-Caen colonne ; P-Ca + P-Fe en pilote), (ii) l'augmentation de la température (> 15 °C) et/ou du temps de séjour (48h et plus) améliore la cinétique d'élimination du phosphore à échelle pilote et (iii) l'implantation d'un filtre réactif garni de laitier de four à arc électrique est limité par le degré de traitement souhaité et la distance du futur chantier (coût du transport).
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Barneze, Arlete Simões. "N2O emission from soil due to urine deposition by grazing cattle and potential mitigation." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-19092013-163347/.
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Grazing pasture is a major system of livestock production in many countries and it has been identified as an important source of N2O from urine deposition on soils. The aim of this study was to determinate the N2O emissions from soil after urine deposition and the emission factor, in addition, determine how temperature and water content of the soil influence these emissions. We also intended to study a potential of mitigation using nitrification inhibitors. Soil and gas samples were collected in traditional livestock areas in Brazil and UK to evaluate the N2O emission dynamics under field conditions. In addition, incubation experiments were conducted to evaluate how temperature and water content affect N2O emissions in the soil and to study the potential mitigation on N2O emission from the soil after urine application, using two distinct nitrification inhibitors. In the field experiment, the N2O emission factor for cattle urine was 0.20% of the applied urine N in Brazil and 0.66% for the UK conditions. The incubation experiments showed the N2O emissions after urine application are higher in soils with high moisture and high temperature. The nitrification inhibitor effectiveness was not statistically significant, however had shown some N2O emission absolute reductions among 6% to 33% comparing with urine only application on the soil. Various physical and biological factors can be influence the effectiveness of the products. It confirmed that urine deposition can contribute to N2O emission from the soil and the temperature and water content can markedly increase these emissions. The nitrification inhibitors have a potential mitigation effect since some decreased emissions of almost 40%. The results in this study are pioneers and can be used as a basis for more complex evaluations and to help with determining the carbon footprint of beef production worldwideConsiderado o maior sistema de produção animal em muitos países, as pastagens tem sido identificadas como uma importante fonte de emissão de N2O, devido à deposição de urina ao solo. O objetivo deste estudo foi determinar as emissões de N2O do solo após a deposição de urina e seu fator de emissão, além disso, determinar como temperatura e teor de água do solo influenciam as emissões. Pretendeu-se também estudar o potencial de mitigação das emissões de N2O usando inibidores de nitrificação. Amostras de solo e de gás foram coletadas em áreas tradicionais de pastagens do Brasil e do Reino Unido para avaliar a dinâmica das emissões de N2O. Experimentos de incubação também foram realizados para avaliar a influência de fatores como temperatura e teor de água no solo nas emissões, além de avaliar o potencial de redução das emissões de N2O do solo após a aplicação da urina, utilizando dois inibidores de nitrificação. Nos experimentos de campo realizados no Brasil e no Reino Unido, o fator de emissão do N2O para a urina foi de 0,20% e 0,66% do nitrogênio na forma de urina bovina aplicada, respectivamente. Nos experimentos de incubação, as emissões de N2O após a aplicação de urina foram maiores em solos com alta umidade e alta temperatura. A eficácia no uso dos inibidores de nitrificação não foi estatisticamente significativa, no entanto mostrou uma redução absoluta entre 6% a 33% nas emissões de N2O comparado com a aplicação de apenas urina ao solo. Vários fatores físicos e biológicos podem ter influenciado a eficácia dos produtos. Dessa forma, confirma-se que a deposição de urina pode contribuir para a emissão de N2O do solo e que a temperatura e o teor de água no solo podem aumentar consideravelmente essas emissões. Os inibidores de nitrificação podem ser usados como um potencial de mitigação, já que houve redução em termos absolutos de quase 40% nas emissões. Os resultados encontrados neste estudo são pioneiros e poderão ser utilizados como base para avaliações mais complexas e contribuir para a determinação da pegada de carbono na produção de carne mundial
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MEDEIROS, Aldair de Souza. "Cultivo de berinjela sob irrigação com água residuária, doses de nitrogênio e fósforo." Universidade Federal de Campina Grande, 2015. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/723.
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A utilização sem controle da água pelo homem para diversos fins tem promovido escassez desse recurso natural principalmente nas regiões áridas e semiáridas e consequentemente limitando o desenvolvimento social e econômico das regiões. O reúso planejado é vastamente utilizado em todo o mundo, entretanto, no Brasil, mesmo possuindo regiões com escassez hídrica, essa prática ainda é pouco difundida. A berinjela (Solanum melongena L.) é uma hortaliça que possui grande importância no mercado de olerícolas no Brasil e no mundo. Objetivou-se com esta pesquisa avaliar a viabilidade técnica do uso de nitrogênio e fósforo juntamente com a irrigação utilizando efluente doméstico pós-tratado em filtro de areia com fluxo intermitente sob o crescimento, produção de fitomassa e floração de plantas de berinjela cultivada em ambiente protegido na região semiárida paraibana. O experimento foi realizado em ambiente protegido, no Centro de Ciências e Tecnologia Agroalimentar (CCTA/UFCG), Campus de Pombal – PB, e cujos tratamentos resultaram na combinação de dois fatores: quatro doses de adubação nitrogenada (N1 - 3,55; N2 - 6,2; N3 - 8,9; N4 - 11,55 g de N/vaso) e quatro doses de adubação fosfatada (P1 - 15,28; P2 - 26,74; P3 - 38,2; P4 - 49,66 g de P/vaso) correspondendo respectivamente a 40; 70; 100; 130% conforme indicação de adubação para a cultura da berinjela quando cultivada em vasos, irrigada com água residuária pós-tratada em filtro de areia intermitente (AR). Adicionou-se um tratamento com 100% da adubação com N e P e cujas plantas eram irrigadas com água de abastecimento (AA). O delineamento experimental adotado foi o de blocos inteiramente casualizados, com os tratamentos arranjados em esquema fatorial 4 x 4 + 1, com quatro repetições. Conclui-se é possível utilizar água residuária na irrigação de plantas de berinjela, nas condições edafoclimáticas do semiárido. Doses de 3,55 g de N e 15,28 g de P por planta quando se utiliza água residuária na irrigação de plantas de berinjela são suficientes para suprir as necessidades nutricionais da cultura. A massa fresca da folha de plantas de berinjela decresceu linearmente com o incremente das doses de N aplicadas. A produção de massa fresca e seca da parte aérea de plantas de berinjela irrigadas com água residuária com 40% da adubação com N e P não diferiu das plantas que receberam 100% da indicação de N e P quando irrigadas com água de abastecimento e de reúso. A floração não foi afetada pelas doses de nitrogênio e fósforo, nem pelos diferentes tipos de águas utilizadas na irrigação. Não houve efeitos significativos da interação dos fatores estudados sobre as variáveis avaliadas em nenhuma das épocas de estudo.
The use without control of water by man for various purposes has promoted scarcity of this natural resource especially in arid and semi-arid regions and consequently limiting the social and economic development of regions. The planned reuse is widely used around the world, however, Brazil, even having regions with water scarcity, this practice is not yet widespread. The eggplant (Solanum melongena L.) is a vegetable that has great importance in vegetable crops market in Brazil and worldwide. The objective of this research was to evaluate the technical feasibility of the use of nitrogen and phosphorus along with irrigation using post- treated wastewater in sand filter with intermittent flow in growth, biomass production and flowering eggplants grown in greenhouse in Paraíba semiarid region. The experiment was conducted in a greenhouse, in the Science and Technology Center Agrifood (CCTA / UFCG), Campus de Pombal - PB, and the treatments resulted in the combination of two factors: four doses of nitrogen (N1 - 3.55; N2 - 6.2; N3 - 8.9; N4 - 11.55 g N / pot) and four doses of phosphorus fertilization (P1 - 15.28; P2 - 26.74; P3 - 38.2; P4 - 49 66 g P / pot) corresponding respectively to 40; 70; 100; 130% as fertilizer indication for eggplants when grown in pots irrigated with treated wastewater post-intermittent sand filter (AR). It was added to a treatment with 100% application of N and P and whose plants were irrigated with water supply (AA). The experimental design was a completely randomized design, with treatments arranged in a factorial 4 x 4 + 1, with four replications. We conclude It follows you can use wastewater to irrigate eggplants, at conditions of semiarid. Doses of 3.55 g of N and 15.28 g P per plant when using wastewater in irrigation eggplants are sufficient to meet the nutritional needs of the crop. The fresh weight of eggplants sheet decreased linearly with the increment of N application. The fresh mass production and shoot dry eggplant plants irrigated with wastewater with 40 % application of N and P did not differ from plants receiving 100 % of the N and P indication when irrigated with water supply and reuse. The flowering was not affected by nitrogen and phosphorus doses, or by different types of water used in irrigation. There was no significant interaction of the factors studied on the variables evaluated in any of the study periods.
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Masselot, David. "Identification et quantification des radicaux libres par spectrométrie de masse : application à l'étude et à la diminution des radicaux libres contenus dans la fumée de cigarette." Lille 1, 2004. http://www.theses.fr/2004LIL10069.
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Les radicaux libres sont capables de réagir avec pratiquement toutes les familles de molécules présentes dans les systèmes biologiques. Ainsi les radicaux libres réagissent en particulier sur l'ADN, induisant des mutations qui conduisent au développement de cancer. De même les radicaux libres réagissent avec les lipides, produisant des phénomènes inflammatoires qui peuvent entraîner le développement de maladies cardiovasculaires. La Résonance Paramagnétique Électronique est la technique classique pour l'identification et la quantification des radicaux libres. Pour la plupart des radicaux en solution une étape de piégeage du radical pour former une espèce radicalaire à longue durée de vie est indispensable. Les milieux réactionnels sièges de réaction d'oxydoréduction conduisent à une transformation de ces adduits en espèces non radicalaires qui ne sont plus détectables par Résonance paramagnétique Électronique. De plus l'identification des radicaux est difficile dans le cas de mélange complexesNous avons développé une nouvelle méthode de détection et de quantification des radicaux libres basée sur la spectrométrie de masse en utilisant l'ionisation par électronébulisation. Nous avons tout d'abord testé les principales familles de piégeurs de radicaux en spectrométrie de masse. Nous en avons optimisé les conditions d'analyse par spectrométrie de masse pour une nitrone, la 2,2,5-triméthyl-3-phényl-3,4-dihydro-2H-pyrrole-l-oxyde (TMPO), spécifique des radicaux centrés sur les hétéroélements et pour un nitroxyde, le 3-amino-2,2,5,5-tetraméthyl-pyrrolidinyloxy (AMP), spécifique des radicaux C-centrés. Nous avons constitué une bibliothèque MS/MS des différents types de radicaux libres permettant leur identification dans des mélanges complexes. Nous avons ensuite appliqué cette méthodologie pour identifier et quantifier les radicaux libres présents dans les fumées de cigarette. La quantité globale de radicaux est de l'ordre de 2. 10+17 radicaux par cigarette fumée en accord avec les études antérieures. Nous avons identifié et quantifié de nombreux radicaux originaux dans la fumée de cigarette comme les radicaux hydroxyle (OH), cyanogène (CN) et méthyle (CH3). Cette étude a également permis de déboucher sur des recherches d'optimisation de filtres permettant la diminution de la teneur en substance radicalaire de la fumée de cigarette. Nos résultats ont montré de plus que les différentes familles de radicaux présentes dans la fumée de cigarette sont éliminés avec des efficacités variables
40
Bouffaud, Marie-Lara. "Histoire évolutive des Poaceae et relations avec la communauté bactérienne rhizosphérique." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-01002644.
Full textAbstract:
Depuis l'apparition de la vie sur terre, les pressions de sélection liées aux interactions biotiques et abiotiques ont généré une forte diversité des formes de vie. Ainsi, chaque espèce eucaryote coévolue avec sa communauté microbienne associée. Dans le cas des plantes, la diversité génétique se traduit au niveau de multiples traits phénotypiques (exsudation de substrats carbonés, architecture racinaire, densité et aération du sol, acidification, etc.) susceptibles d'influer sur les interactions avec les populations microbiennes du sol, et donc sur la composition et le fonctionnement de la communauté microbienne rhizosphérique. Notre hypothèse est que les différences entre communautés bactériennes rhizosphériques sont proportionnelles aux distances évolutives entre partenaires végétaux. L'objectif de cette thèse était donc de déterminer l'importance, dans le cas des Poacées et notamment du maïs, de l'histoire évolutive de la plante dans la capacité de sélection des communautés bactériennes de la rhizosphère. Les analyses faites à l'aide d'une puce à ADN taxonomique 16S indiquent que la composition de la communauté rhizobactérienne dépend du groupe génétique de maïs mais n'est pas liée aux marqueurs microsatellites de diversité du maïs. Par contre, à l'échelle des Poacées, une corrélation a été trouvée entre la phylogénie végétale et la composition de la communauté bactérienne (voire la prévalence de taxons bactériens particuliers). Cette corrélation n'était pas significative quand l'étude était limitée à l'effectif, le niveau de transcription de nifH ou la diversité du groupe fonctionnel des bactéries fixatrices d'azote. En conclusion, l'histoire évolutive du partenaire végétal à l'échelle des Poacées (mais pas à celle du maïs) est un facteur conditionnant les interactions avec les groupes bactériens taxonomiques (mais pas nécessairement fonctionnels) de la rhizosphère
41
Coetzee, Martha Anna Aletta. "The effectivity of a biological filter for nitrogen removal in ventilated pit latrines." 2012. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000970.
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Beuthe, Birgitta M. C. "Laboratory evaluation of a peat filter for nitrogen removal in septic tank effluent." 1992. http://catalog.hathitrust.org/api/volumes/oclc/25881949.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 1992.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 119-135).
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Bushman, Jennifer L. "Transport and transformations of nitrogen compounds in effluent from sand filter-septic system draintile fields." Thesis, 1996. http://hdl.handle.net/1957/34989.
Full textAbstract:
A total of 44 intermittent sand filter-septic systems, in five counties of Western
Oregon, were sampled over a three-month period during the summer of 1995. The sand
filter systems varied in age from 36 months up to 167 months (3 to 13.9 years). Liquid
samples were taken from the septic tank and distribution box. In addition, soil samples
were taken adjacent to the disposal trench and away from the disposal field area (control).
All samples were analyzed for Total Kjeldahl Nitrogen (TKN) and nitrate and nitrite.
Nitrite was not detected in any of the samples. The average removal of total nitrogen
(TKN + nitrate) through the filter was found to be 43%. Nitrate was determined to be the
dominant form of nitrogen in the sand filter effluent making up 94% of the total nitrogen.
The age of the system was found not to be a predictor of the system's performance. Once
the effluent entered the disposal field, little if any transformation of nitrogen occurred at an
average depth of 30 inches (76.2 cm).Graduation date: 1996
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Lee, Tzung-Hsien, and 李宗憲. "Studies on the Removal of Nitrogen and Phosphorous in Domestic Wastewater by Anoxic-Aerobic Biological Filter." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/54743104388676225941.
Full textAbstract:
碩士淡江大學
水資源及環境工程學系
86
Abstract： To search the efficient way and low cost of the treatment technology of wastewater is our goal now. The purpose of this treatment is to use high-ration area biological filter to increase treatment wastewater loading with high efficiency in short time. This study, which utilized a pilot plant of anoxic- aerobic biological filter process, was an experiment of the typical municipal wastewater. The hydraulic retention time of this system was controlled between 5.92-11 hours. The other controlled conditions w1. When the hydraulic retention time is controlled between 5.92-11.84 hours，the removal rate of organic matter is 78%-87%, Further more, the nitrogen removal reaches the level of l998 when the hydraulic retention time more than 11 hours. In this case, the phosphorus removal rate is only 20%-33%. However, the removal rate of organic matter reach 9O% in 5.92 hours， which is only 1/2 -1/4 of original treatment time. In this case, the removal rate of NH4-N reaches more than 7O% and the phosphorus is 66%-34%.2. The NOx-N consistency increases not only when the aerobic-tank hydraulic retention time is more than 5 hours. Moreover, when the water temperature has a change of 1O℃, it causes a 3O% difference of the nitrification rate. 3. When the NOx-N consistency is over 3.5 mg/L in the anoxic-tank, it happens to uptake phosphorus and doesn''t release phosphorus. Moreover, the higher the NOx-N consistency gets, the lower the removal rate of phosphorus become.4. When the organic matter consistency of influent discharge increases, the P04-P of anoxic-tank also increases. When the influent wastewater SBOD5:P≧20,the effusive discharge is below 1.0 mg/L. 5. In aerobic-tank, when the ORP value becomes higher, the NOx-N consistency goes increasingly. In anoxic-tank, when the ORP value becomes lower, the PO4-P consistency goes increasingly.6. Due to the relationship of the difference of organic matter, the volume loading, area loading and removal rate of NH4-N and PO4-P, it is found that the higher the pollutant loading gets, the easier the contact falter blocks up. It causes the decrease of removal rate of each pollutant.
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Wei, Lian I., and 連奕偉. "The Studies on the Removal of Nitrogen and Phosphorus in Domestic Sewage by Aerated Submerged Filter." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/43942406572381533661.
Full textAbstract:
碩士淡江大學
水資源及環境工程所
82
To improve the deficiencies of the traditional Aerated Submerged Filters (ASF) in removing Nitrogen and Phosphorus ,a study of treating domestic sewage from the Taipei Min- Seng Domestic Sewage Treatment Plant by operating an ASF with intermettent aeration patterns of different aeration time scales(100％, 75％ and 50％ of the Hydraulic Retention Time, HRT) was conducted. The results of the studies are found as follow: 1.Under the condition of 75％ aeration time scales of an 8 hours'' HRT, a 61％ TN removal can be accomplished, and of an 12 hours'' HRT, a 77％ amonia nitrogen removal can be accomplished. 2.While the influent ratio of TBOD/TN =3.23, SBOD/TN =1.3, a 64％ TN removal can be accomplished. In the other hand, and the influent ratio of TBOD/TN=1.79, SBOD/ TN=0.38, only 1％ TN is removed. 3.Every substrate has a linear relationship between the unit area loading rates and unit area removal rates. For example, the relationship is Lr = 0.88Lo + 0.024 for TBOD under the condition of 100％ aeration time scales. 4.The unit area removal rate is 0.196 g amonia nitrogen per squared meter per day under the condition of 100％ aera- tion time scales when the unit area loading rate is 0.3g amonia nitrogen per squared meter per day. 5.Because of the low wash-out frequency of Biomass, the removals of TP were not obvious in the intermettent aeration systems. 6.When the unit area loading rates are higher than 0.256g TN/ per squared meter per day, the operation of 75％ aera- tion time scale can obtain higher unit area removal rates
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HO, CHIH CHENG, and 何志誠. "Nitrogen removal through simultaneous nitrification and denitrification in an aerated biological filter using oyster shell medium." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/17647755540524905431.
Full textAbstract:
碩士國立臺南大學
生態科學與技術學系環境生態碩士班
105
Due intensive discharge of nutrient-containing wastewater, eutrophication has become a common problem of many surface waters. Nitrogen removal from wastewaters is a primary solution for easing eutrophication of these waterbodies. Biological nitrogen removal is commonly adopted for nitrogen removal due to its low cost and environmental friendliness. The various biological nitrogen removing processes can be broadly categorized as suspended growth and attached growth systems. Although suspended growth process such as activated sludge systems has been popular among wastewater treatment facilities, attached grow systems such as biological aerated filters (BAFs) have gained a growing popularity in recent years due to their simplicity, stability, and low sludge production. In this study, a laboratory scale BAF using oyster shell medium was used to test its nitrogen removing efficiency through simultaneous nitrification and denitrification (SND). Results of lab studies show that a long term nitrogen removal efficiency of 44.7 % was achieved when the filter is completely mixed. A slightly lower efficiency of 41.2 % was also attained when the reactor is partially aerated. Best dissolved oxygen levels were 3.0 and 3.5 respectfully for the complete mixed system and the partially mixed system. The results also indicate that a carbon to nitrogen ratio of 12 provided best SND efficiency of the system. It is concluded that, a BAF system using oyster shells as growth medium provides effluents that meet current regulations. The system is also simple and easy to operate and maintain, which is especially suitable for the treatment of municipal wastewater from small communities and businesses.
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Johnson, Charles G. "Single-pass sand filter and soil dispersal unit performance in reducing pathogens and nitrogen from domestic wastewater." 2001. http://catalog.hathitrust.org/api/volumes/oclc/50118325.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 2001.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 75-77).
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Kardohely, Stephanie L. "Combining existing trickling filter treatment with nitrogen removal technology : optimizing a modified single-sludge nitrification-denitrification system /." 2000. http://emp3.hbg.psu.edu/theses/available/etd-10222001-192210/.
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LIN, SHANG-EN, and 林上恩. "Nitrogen Removal from Domestic Wastewater through Simultaneous Nitrification and Denitrification in a Polyeurathane Foam Biological Aerated Filter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/85278009222357041393.
Full textAbstract:
碩士國立臺南大學
生態科學與技術學系環境生態碩士班
104
The discharge of excessive nutrients has caused eutrophication of surface waterbodies throughout the world. Nutrient removal has become a necessary procedure for wastewater treatment. In nitrogen removal, biological processes are currently the major technology employed in wastewater treatment. Biofilm technologies has been extensive studied for use in nitrogen removal from wastewater. Simultaneous nitrification and denitrification (SND) using biofilm reactors has the advantage of small size, low sludge production, and system stability. In this study, a biological aerated filter (BAF) was designed for the study of SND in attached growth systems. Synthetic domestic wastewater was used as feeding water, with polyurethane foams used as biological carriers. The reactor was divided in to an aerobic and an anaerobic compartments to facilitate SND. The efficiency of the system and optimal operating parameters were explored. The study tested three different dissolved oxygen concentrations (1.5, 2.5, 3.5 mg / L) with three different degrees of tank separation (8, 12, and 16 connecting holes). With a factorial design, the nitrogen removing efficiency of nine operating conditions were compared. The system reached an optimum nitrogen removal under the condition of 12 holes and dissolved oxygen of 2.5 mg/L. Long-term test using the optimal conditions showed that the removal rate is 54.6 ± 4.8 % for dissolved inorganic nitrogen and 92.9 ± 2.7 % for COD. The study shows that a BAF using polyurethane foams is a simple, stable, and effective bioreactor for nitrogen removal. It is capable of simultaneously removing organic matters and nitrogen from wastewater.
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Mensing, Michael. "Mass selected low energy ion-assisted growth of epitaxial GaN thin films: Impact of the nitrogen ion species." 2020. https://ul.qucosa.de/id/qucosa%3A71752.
Full textAbstract:
In this thesis, a custom quadrupole mass filter setup was established to independently investigate the impact of the most prominent ion species that are present during ion-assisted deposition. The setup was applied to the low temperature epitaxial growth of GaN thin films on 6H-SiC substrates. Atomic nitrogen ions at higher ion kinetic energies were for the first time independently identified to be the predominant cause of deteriorating crystalline qualities during growth. Precise control of the ion beam parameters yielded the capability to vary the average GaN phase content from almost purely wurtzite to the meta-stable zinc blende GaN phase. Even in case of comparably high crystalline quality, the atomic and molecular nitrogen ions were independently determined to yield distinct thin film topographies throughout the entire observed evolution of the thin film formation.:Bibliographical Description
1 Introduction
1.1 Epitaxial Thin Film Growth
1.2 Ion-Beam Assisted Deposition
1.2.1 Influence of Energetic Particles
1.2.2 Ion-atom Arrival Ratio
1.3 Gallium Nitride
2 Methods
2.1 Setup of the Deposition System
2.1.1 Knudsen Effusion Cell
2.1.2 Reflection High-Energy Electron Diffraction
2.1.3 Auger Electron Spectroscopy
2.1.4 Ion Sources
2.2 Quadrupole Mass Filter System
2.2.1 Components
2.2.2 Working Principle of a Quadrupole Mass Filter
2.2.3 Alternative Mass Filters
2.3 X-ray Diffraction and Reflectivity
2.4 Atomic Force Microscopy
2.5 Transmission Electron Microscopy
3 Results and Discussions
3.1 Characterization of the Quadrupole Mass Filter System
3.1.1 Mass Filter Performance and Resolution
3.1.2 Ion Beam Characteristics
3.1.3 Space Charge Considerations
3.1.4 Conclusions
3.2 Influence of the I/A Ratio and Ion Kinetic Energy
3.2.1 Determination of the GaN Phase Composition
3.2.2 Film Topography and Growth Mode
3.2.3 Crystal Structure and Orientation
3.2.4 Microstructure at the Interface
3.2.5 Conclusions
3.3 Impact of the Ion Species on Growth Instabilities
3.3.1 Growth Rates and Thin Film Topography
3.3.2 Crystal Structure
3.3.3 Growth Mode and RHEED pattern evolution
3.3.4 Conclusions
4 Summary and Conclusions
Bibliography
Complete Publication List of the Author
Acknowledgments
Declaration of AuthorshipIn dieser Arbeit wurde ein maßgefertigter Quadrupol-Massenfilteraufbau etabliert, um die Auswirkungen der prominentesten Ionenspezies, die während der ionengestützten Abscheidung vorhanden sind, unabhängig voneinander zu untersuchen. Der Aufbau wurde für das epitaktische Niedertemperatur-Wachstum von GaN-Dünnschichten auf 6H-SiC-Substraten angewendet. Atomare Stickstoffionen bei höheren kinetischen Ionenenergien wurden zum ersten Mal in der Abwesenheit anderer Spezies als die dominierende Ursache für die Verschlechterung der kristallinen Qualität während des Wachstums identifiziert. Eine präzise Kontrolle der Ionenstrahlparameter ergab die Fähigkeit, den durchschnittlichen GaN-Phasengehalt von der fast reinen Wurtzit- bis zur metastabilen Zinkblende-GaN-Phase zu variieren. Selbst bei vergleichbar hoher kristalliner Qualität weisen die mit atomaren und molekularen Stickstoffionen hergestellten Schichten unabhängig voneinander verschiedene Topographien auf, die sich während der gesamten beobachteten Entwicklung der Dünnschichtbildung deutlich abzeichneten.:Bibliographical Description 1 Introduction 1.1 Epitaxial Thin Film Growth 1.2 Ion-Beam Assisted Deposition 1.2.1 Influence of Energetic Particles 1.2.2 Ion-atom Arrival Ratio 1.3 Gallium Nitride 2 Methods 2.1 Setup of the Deposition System 2.1.1 Knudsen Effusion Cell 2.1.2 Reflection High-Energy Electron Diffraction 2.1.3 Auger Electron Spectroscopy 2.1.4 Ion Sources 2.2 Quadrupole Mass Filter System 2.2.1 Components 2.2.2 Working Principle of a Quadrupole Mass Filter 2.2.3 Alternative Mass Filters 2.3 X-ray Diffraction and Reflectivity 2.4 Atomic Force Microscopy 2.5 Transmission Electron Microscopy 3 Results and Discussions 3.1 Characterization of the Quadrupole Mass Filter System 3.1.1 Mass Filter Performance and Resolution 3.1.2 Ion Beam Characteristics 3.1.3 Space Charge Considerations 3.1.4 Conclusions 3.2 Influence of the I/A Ratio and Ion Kinetic Energy 3.2.1 Determination of the GaN Phase Composition 3.2.2 Film Topography and Growth Mode 3.2.3 Crystal Structure and Orientation 3.2.4 Microstructure at the Interface 3.2.5 Conclusions 3.3 Impact of the Ion Species on Growth Instabilities 3.3.1 Growth Rates and Thin Film Topography 3.3.2 Crystal Structure 3.3.3 Growth Mode and RHEED pattern evolution 3.3.4 Conclusions 4 Summary and Conclusions Bibliography Complete Publication List of the Author Acknowledgments Declaration of Authorship