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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Total nutrient uptake and partitioning in midsouthern U.S. irrigated soybean

Pieralisi, Brian Kimbrell 01 May 2020 (has links)
Soybean [Glycine max (L.) Merr.] biomass and yield has increased over the past several decades in the midsouthern United States; therefore, a better understanding of the nutrient requirements of the crop is needed. Nutrient uptake and partitioning in soybean is fundamental to understanding the physiology of nutrient accumulation relative to crop yield. Technological advances and improved management strategies in soybean production have contributed to significant yield increases. Research was established in 2017 and 2018 in Stoneville, MS, to evaluate soybean nutrient uptake and partitioning across multiple soybean cultivars and two planting dates. Coarse- and fine-textured soils commonly cropped in Mississippi under furrow irrigation were utilized. Soybean total aboveground biomass was collected at multiple growth stages, including V4, R2, R5.5, R6.5, and R8. At reproductive stages R5.5 to R8, soybean aboveground biomass was partitioned into senesced leaves, pods, and seeds. All biomass components were analyzed for content of primary macronutrients. Two soybean cultivars for each of four herbicide-resistant technologies were selected to represent subplot treatments. The greatest yield was produced by dicamba- and glyphosate-tolerant HT, followed by glufosinate tolerant, followed by conventional HT. Soybean planted in April produced grain yield greater than May planted soybean. Averaged across four site years, field removal of total N, P2O5, and K2O partitioned into the seed at physiological maturity was approximately 175 kg N ha-1, 33 kg P2O5 ha-1, and 120 kg K2O ha-1.
2

Crescimento do lúpulo influenciado por calagem e fornecimento de fósforo / Growth hollow influenced by calage and supply of phosphorus

Oliveira, Marcus Vinícius Ribeiro de 20 December 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-03-07T16:19:03Z No. of bitstreams: 1 PGCS16MA157.pdf: 1361715 bytes, checksum: 2c336e09922581d425e029f59bc55512 (MD5) / Made available in DSpace on 2018-03-07T16:19:03Z (GMT). No. of bitstreams: 1 PGCS16MA157.pdf: 1361715 bytes, checksum: 2c336e09922581d425e029f59bc55512 (MD5) Previous issue date: 2016-12-20 / Capes / Hops (Humulus lupulus L.) is a perennial climbing vine belonging to the family Cannabaceae. It is important in the manufacture of medicines, cosmetic products and mainly in brewing production. The objective of this research was to evaluate the growth of hops (Humulus lupulus L.) as a function of 4 different levels of acidity and 4 different levels of phosphate fertilization. The experiment was carried out in a greenhouse on UDESC - Lages (SC), between December 2015 and March 2016. Hop seedlings were collected from a rural property at São Mateus do Sul (PR). The soil used was an Alumínic Humic Cambisol from Lages (SC) and it were limed, incubated and mixed until they achieved the chosen pH (5.2, 6.0 and 6.5). Following this treatment, 1.5 kg of soil were placed in plastic pots and fertilized with phosphate (90, 180, 360 kg.ha-1). The phosphorous source used was the mono-ammonium phosphate (MAP). The seedlings were transplanted to the plastic pots with soil and left for 120 days until their harvest. The root, stem and shoot were analyzed separately, being determined the dry mass, total nitrogen, phosphorus, potassium, calcium, magnesium and plant height. Calcium, magnesium, potassium, organic matter, aluminum, aluminum plus hydrogen, pH-water, pH-CaCl2 and pH SMP were analyzed using the methodology indicated by Tedesco et al. (1995). In relation to the pH, the dry masses of the aerial part, root and total were also significant, they also had the P, the Ca and the K in the root and in the aerial part were Ca and N. In relation to the P2O5 doses they obtained differences dry mass In the aerial part, root and total, the P in the stem, root and the Mg in the aerial part. The variables: plant height, P and K in aerial part, Mg and N in root and N in stem were interacted with liming and phosphate fertilization. There were no significant differences in dry matter, Ca, Mg and K in the stem. For the conditions performed in the experiment, the analyzed variables that obtained the best results were pH 5,2 and the dose of 180 kg.ha-1 of P2O5 / O lúpulo (Humulus lupulus L.) é uma trepadeira, perene e pertencente à família Cannabaceae. Tendo sua importância na fabricação de remédios, produtos cosméticos e principalmente na produção cervejeira. O objetivo desta pesquisa foi avaliar o crescimento da cultura do lúpulo (Humulus lupulus L.), em relação a 4 diferentes níveis de acidez e 4 diferentes níveis de adubação fosfatada. O experimento foi realizado em casa de vegetação da UDESC - Lages (SC), entre dezembro de 2015 até março de 2016. As mudas de lúpulo foram coletadas de uma propriedade rural da cidade de São Mateus do Sul (PR). O solo utilizado foi um Cambissolo Húmico Alumínico do município de Lages (SC), os solos foram calcareados, incubados e misturados até ficarem no pH (pH natural; pH 5,2; pH 6,0 e pH 6,5). Logo após esse período foram postos 1,5 kg de solo em vasos plásticos e adubados níveis de adubação fosfatada (0 ; 90 ; 180 ; 360 kg.ha-1), sendo a fonte utilizada a solução de mono - amônio fosfato (MAP). As mudas foram transplantadas para os vasos plásticos com solo e deixadas por 120 dias até a sua colheita. Foram analisadas separadamente a raiz, o caule e a parte aérea, sendo determinadas a massa seca, nitrogênio total, fósforo, potássio, cálcio, magnésio e altura de planta. No solo foram analisados os teores de cálcio, magnésio, potássio, matéria orgânica, alumínio, alumínio mais hidrogênio, pH-água, pH-CaCl2 e pH SMP utilizando a metodologia indicada por Tedesco et al (1995). Em relação ao pH tiveram diferenças significativas as massas secas da parte aérea, raiz e total, também tiveram o P, o Ca e o K na raiz e na parte aérea foram Ca e N. Já em relação às doses de P2O5 Obtiveram diferenças massa seca na parte aérea, raiz e total, o P no caule, raiz e o Mg na parte aérea. Tiveram interação calagem e adubação fosfatada as variáveis: altura de planta, P e K na parte aérea, Mg e N na raiz e o N no caule. Não obtiveram diferenças significativas a massa seca, o Ca,o Mg e o K no caule. Para as condições realizadas no experimento, as variáveis analisadas que obtiveram melhores resultados foram no pH 5,2 e a dose de 180 kg.ha-1 de P2O5
3

Morphologie und Degradation von O2, Pt│YSZ-Elektrodensystemen / Morphology and Degradation of O2, Pt│YSZ-Electrodes

Vonau, Corinna 22 October 2015 (has links) (PDF)
In der vorliegenden Arbeit wird erstmals systematisch der Einfluss von gasförmigen und festen Verunreinigungen auf das O2, Pt│YSZ- Elektrodensystem am praxisnahen Beispiel der Lambdasonde untersucht. Dazu wurden Festelektrolyt- und Elektrodenmaterialien unterschiedlicher Zusammensetzung und Morphologie den realen Abgasbedingungen nachempfundenen, chemischen und physikalischen Einflüssen ausgesetzt und in Bezug auf Langzeitstabilität, Sensitivität und Wirkmechanismen untersucht. Im Einzelnen lag der Fokus der Untersuchungen auf zwei Ausführungsformen von Elektroden, die sich vor allem durch mikro- bzw. nanoskalige Partikelgrößenverteilungen sowie der Platin/YSZ-Zusammensetzung unterschieden und als Mikro- bzw. Nano-Elektrode bezeichnet wurden. Der Einfluss von Siliciumdioxid als gezielt dem Festelektrolyten beigemischte intrinsische Vergiftung sollte in Wechselwirkung zu den extrinsischen Verunreinigungen wie Natriumionen, Wasserdampf und Phosphorpentoxid untersucht werden. Im Unterschied zu den in der Literatur betrachteten, vereinfachten Modellsystemen konnten damit erstmals Wechselwirkungen beschrieben werden, die zu einem tieferen Verständnis des realen Sensorverhaltens, vor allem der Degradation beitragen. Insbesondere ist es gelungen, ein Modell für die Sauerstoffreaktion an geschädigten Elektroden aufzustellen. Neben der bekannten elektrochemischen Reduktion von Sauerstoff spielen die Transportvorgänge an der Elektrodenoberfläche eine entscheidende Rolle, über die in der Literatur bisher nur wenig bekannt war.
4

Caracterização das propriedades físicas e termoelétricas de filmes Cu-Ni-P obtidos por deposição química sobre silício. / Characterization of the physical and thermoelectric properties of Cu-Ni-P films obtained by chemical deposition on silicon.

Siqueira, Felipe Tomachevski 04 September 2017 (has links)
Superfícies de silício (100) foram inicialmente pré-ativadas em uma solução diluída de ácido fluorídrico contendo PdCl2. Após essa etapa, filmes finos de Cu-Ni-P foram quimicamente depositados utilizando-se um banho químico contendo 15g/l NiSO4.6H2O; 0.2 g/l CuSO4.5H2O; 15 g/l Na2HPO2.H2O e 60 g/l Na3C6H5O7.2H2O na temperatura de 80ºC onde foi adicionado NH4OH até que o pH da solução atingisse 8,0. Foi observado que as porcentagens estequiométricas de Ni e Cu variaram substancialmente no intervalo de 1 a 3min, e se tornaram praticamente estáveis em 50% e 35%, respectivamente, quando o tempo de deposição foi superior a 3min. Além disso, a porcentagem de P permaneceu quase constante em torno de 17-18% para todos os tempos de deposição. A distribuição de alturas nas imagens FE-SEM resultou bimodal para tempos na faixa de 1 e 3min onde a predominância do modo de maior altura aumentou substancialmente para o tempo de 3min. Tal fato serviu para corroborar a evolução da morfologia superficial de grãos menores com diâmetros na faixa de 0,02 a 0,1µm, predominantemente compostos de Ni, para grãos maiores, na faixa de 0,1 a 0,3µm e predominantemente compostos de Cu. Após um recozimento a 100oC durante 10min em ambiente 20%O2+80%N2, observou-se uma mudança na morfologia superficial em que os aglomerados de fósforo (Po) desapareceram enquanto que os grãos que compunham a imagem não mudaram substancialmente de tamanho após o recozimento. Apesar do desaparecimento dos aglomerados, a concentração de fósforo ainda apresentou valor semelhante ao valor de antes do recozimento (~17-18%). As análises de difração de raios X (XRD) indicaram o aparecimento de um pico de difração alargado ao redor de 22,6º característico de óxido de fósforo (P2O5) com estrutura vítrea amorfa significando que o fósforo em estado puro foi transformado na sua forma oxidada. Por outro lado, picos substancialmente menos intensos de NiO, Ni3P e Si5P6O25 foram observados. Verificou-se também para os filmes recozidos em N2+O2 que a resistividade aumentou para todos os tempos de deposição e o poder termoelétrico medido resultou quase independente do tempo de deposição e, portanto, foi quase independente da espessura do filme para as diferentes temperaturas medidas na faixa de 40 a 120ºC. / Silicon surfaces (100) were initially pre-activated in a diluted hydrofluoric acid solution containing PdCl2. After this step, Cu-Ni-P thin films were chemically deposited using a chemical bath containing 15g/l NiSO4.6H2O; 0.2 g/l CuSO4.5H2O; 15 g/l Na2HPO2.H2O e 60 g/l Na3C6H5O7.2H2O at the temperature of 80°C where NH4OH was added until the pH of the solution reached 8.0. It was observed that the stoichiometric percentages of Ni and Cu varied substantially for deposition time in the range of 1 to 3min, and became practically invariant at 50% and 35%, respectively, when the deposition time was greater than 3min. In addition, the percentage of P remained almost constant at around 17-18% for all the deposition times. The distribution of heights in the FE-SEM images resulted bimodal for times in the range of 1 and 3min where the predominance of the higher average height mode increased substantially for the time of 3min. This fact allowed one to corroborate the superficial morphology passing from smaller grains with diameters in the range of 0.02 to 0.1µm, predominantly composed of Ni to larger grains in the range of 0.1 to 0.3µm with Cu predominant composition. After an annealing at 100°C for 10min in a 20%O2+80%N2 environment, the phosphorus (Po) agglomerates disappeared while the size of the grains did not change substantially after the annealing. Despite the disappearance of the agglomerates, the phosphorus concentration still remained unchanged (~ 17-18%). X-ray diffraction (XRD) analysis showed a broad diffraction peak around 22.6º, which is characteristic of an amorphous vitreous structure (P2O5). In addition, substantially less intense peaks showing small amounts of NiO, Ni3P and Si5P6O25 were observed. It was also verified for the N2+O2 annealed films that the resistivity increased for practically all the deposition times and the measured thermoelectric power was almost independent of the deposition time and, therefore, was also independent of the film thickness for the various temperatures in the range from 40 to 120ºC.
5

Total Synthesis of the Putative Structure of Tridachiahydropyrone

Jeffery, David William, david.jeffery@awri.com.au January 2005 (has links)
Polypropionate marine natural products have emerged as a class of compounds that display a high degree of structural diversity. Specifically, metabolites such as that reported as tridachiahydropyrone (7), isolated from sacoglossan molluscs, display novel ring systems. The introductory chapter gives some background on tridachione marine natural products and outlines the isolation of metabolites from several species of sacoglossan mollusc. Chapter One also gives examples of the utility of the tandem conjugate addition-Dieckmann condensation approach being applied to the synthesis of these compounds. Chapter Two describes the development of the tandem conjugate addition-Dieckmann condensation and subsequent trans methylation approach to cyclohexenone rings. The synthetic strategy utilised chiral, functionalised cyclohexenone rings as synthons in the formation of bicyclic ring systems, so development of the carbocyclic ring formation was of vital importance to the overall strategy. Examples are given which confirm the viability of the proposed synthetic route to cyclohexenones such as 91, 92 and 104 from the reaction of [alpha,beta]-unsaturated carbonyl compounds 39 and 59 with dialkyl and dialkenyl Gilman cuprates. Chapter Three describes the incorporation of chiral cyclohexenone 117 into the bicyclic framework of model compound 105, analogous to the marine natural product reported as tridachiahydropyrone (7). The chapter explores the use of cyclohexenone precursor 43 that contained the total carbon framework of the bicyclic core of the desired pyrone. Once again, a tandem conjugate addition-cyclisation reaction was employed using a dialkyl Gilman cuprate, followed by trans methylation to give the requisite cyclohexenone synthon 117. A novel Eaton’s reagent-promoted intramolecular cyclisation of acid 122 to pyrone 123 was then effected. Subsequent O-methylation afforded [alpha]-methoxy-[beta]-methyl-[gamma]-pyrone 105 as a single enantiomer, which had the identical core structure to the natural product. The structure, including relative stereochemistry of 105, was confirmed by single crystal X-ray analysis. Chapter Four builds on the previous two chapters and describes the conjugate addition-cyclisation with a higher order Gilman cuprate derived from vinyl bromide 44, which would deliver the vinyl side-chain required for the synthesis of reported natural product 7. The same acyclic precursor 43 as used in Chapter Three was cyclised and methylated to yield yet another cyclohexenone synthon 41. A single crystal X-ray analysis of related alcohol 162 confirmed the relative stereochemistry and structure. Another novel P2O5-mediated intramolecular cyclisation was achieved to give pyrone 168 and O-methylation provided a compound with the reported structure of natural product 7 as a single enantiomer. The structure of synthetic 7 was established unequivocally through extensive NMR studies. Comparisons of spectral data confirmed that natural tridachiahydropyrone was not the same as synthetic compound 7, so revision of the assigned natural product structure is warranted. Several other analogues were also synthesised using this methodology, highlighting the versatility of the method under development.
6

Caracterização das propriedades físicas e termoelétricas de filmes Cu-Ni-P obtidos por deposição química sobre silício. / Characterization of the physical and thermoelectric properties of Cu-Ni-P films obtained by chemical deposition on silicon.

Felipe Tomachevski Siqueira 04 September 2017 (has links)
Superfícies de silício (100) foram inicialmente pré-ativadas em uma solução diluída de ácido fluorídrico contendo PdCl2. Após essa etapa, filmes finos de Cu-Ni-P foram quimicamente depositados utilizando-se um banho químico contendo 15g/l NiSO4.6H2O; 0.2 g/l CuSO4.5H2O; 15 g/l Na2HPO2.H2O e 60 g/l Na3C6H5O7.2H2O na temperatura de 80ºC onde foi adicionado NH4OH até que o pH da solução atingisse 8,0. Foi observado que as porcentagens estequiométricas de Ni e Cu variaram substancialmente no intervalo de 1 a 3min, e se tornaram praticamente estáveis em 50% e 35%, respectivamente, quando o tempo de deposição foi superior a 3min. Além disso, a porcentagem de P permaneceu quase constante em torno de 17-18% para todos os tempos de deposição. A distribuição de alturas nas imagens FE-SEM resultou bimodal para tempos na faixa de 1 e 3min onde a predominância do modo de maior altura aumentou substancialmente para o tempo de 3min. Tal fato serviu para corroborar a evolução da morfologia superficial de grãos menores com diâmetros na faixa de 0,02 a 0,1µm, predominantemente compostos de Ni, para grãos maiores, na faixa de 0,1 a 0,3µm e predominantemente compostos de Cu. Após um recozimento a 100oC durante 10min em ambiente 20%O2+80%N2, observou-se uma mudança na morfologia superficial em que os aglomerados de fósforo (Po) desapareceram enquanto que os grãos que compunham a imagem não mudaram substancialmente de tamanho após o recozimento. Apesar do desaparecimento dos aglomerados, a concentração de fósforo ainda apresentou valor semelhante ao valor de antes do recozimento (~17-18%). As análises de difração de raios X (XRD) indicaram o aparecimento de um pico de difração alargado ao redor de 22,6º característico de óxido de fósforo (P2O5) com estrutura vítrea amorfa significando que o fósforo em estado puro foi transformado na sua forma oxidada. Por outro lado, picos substancialmente menos intensos de NiO, Ni3P e Si5P6O25 foram observados. Verificou-se também para os filmes recozidos em N2+O2 que a resistividade aumentou para todos os tempos de deposição e o poder termoelétrico medido resultou quase independente do tempo de deposição e, portanto, foi quase independente da espessura do filme para as diferentes temperaturas medidas na faixa de 40 a 120ºC. / Silicon surfaces (100) were initially pre-activated in a diluted hydrofluoric acid solution containing PdCl2. After this step, Cu-Ni-P thin films were chemically deposited using a chemical bath containing 15g/l NiSO4.6H2O; 0.2 g/l CuSO4.5H2O; 15 g/l Na2HPO2.H2O e 60 g/l Na3C6H5O7.2H2O at the temperature of 80°C where NH4OH was added until the pH of the solution reached 8.0. It was observed that the stoichiometric percentages of Ni and Cu varied substantially for deposition time in the range of 1 to 3min, and became practically invariant at 50% and 35%, respectively, when the deposition time was greater than 3min. In addition, the percentage of P remained almost constant at around 17-18% for all the deposition times. The distribution of heights in the FE-SEM images resulted bimodal for times in the range of 1 and 3min where the predominance of the higher average height mode increased substantially for the time of 3min. This fact allowed one to corroborate the superficial morphology passing from smaller grains with diameters in the range of 0.02 to 0.1µm, predominantly composed of Ni to larger grains in the range of 0.1 to 0.3µm with Cu predominant composition. After an annealing at 100°C for 10min in a 20%O2+80%N2 environment, the phosphorus (Po) agglomerates disappeared while the size of the grains did not change substantially after the annealing. Despite the disappearance of the agglomerates, the phosphorus concentration still remained unchanged (~ 17-18%). X-ray diffraction (XRD) analysis showed a broad diffraction peak around 22.6º, which is characteristic of an amorphous vitreous structure (P2O5). In addition, substantially less intense peaks showing small amounts of NiO, Ni3P and Si5P6O25 were observed. It was also verified for the N2+O2 annealed films that the resistivity increased for practically all the deposition times and the measured thermoelectric power was almost independent of the deposition time and, therefore, was also independent of the film thickness for the various temperatures in the range from 40 to 120ºC.
7

Morphologie und Degradation von O2, Pt│YSZ-Elektrodensystemen

Vonau, Corinna 02 October 2015 (has links)
In der vorliegenden Arbeit wird erstmals systematisch der Einfluss von gasförmigen und festen Verunreinigungen auf das O2, Pt│YSZ- Elektrodensystem am praxisnahen Beispiel der Lambdasonde untersucht. Dazu wurden Festelektrolyt- und Elektrodenmaterialien unterschiedlicher Zusammensetzung und Morphologie den realen Abgasbedingungen nachempfundenen, chemischen und physikalischen Einflüssen ausgesetzt und in Bezug auf Langzeitstabilität, Sensitivität und Wirkmechanismen untersucht. Im Einzelnen lag der Fokus der Untersuchungen auf zwei Ausführungsformen von Elektroden, die sich vor allem durch mikro- bzw. nanoskalige Partikelgrößenverteilungen sowie der Platin/YSZ-Zusammensetzung unterschieden und als Mikro- bzw. Nano-Elektrode bezeichnet wurden. Der Einfluss von Siliciumdioxid als gezielt dem Festelektrolyten beigemischte intrinsische Vergiftung sollte in Wechselwirkung zu den extrinsischen Verunreinigungen wie Natriumionen, Wasserdampf und Phosphorpentoxid untersucht werden. Im Unterschied zu den in der Literatur betrachteten, vereinfachten Modellsystemen konnten damit erstmals Wechselwirkungen beschrieben werden, die zu einem tieferen Verständnis des realen Sensorverhaltens, vor allem der Degradation beitragen. Insbesondere ist es gelungen, ein Modell für die Sauerstoffreaktion an geschädigten Elektroden aufzustellen. Neben der bekannten elektrochemischen Reduktion von Sauerstoff spielen die Transportvorgänge an der Elektrodenoberfläche eine entscheidende Rolle, über die in der Literatur bisher nur wenig bekannt war.:1 Einleitung 1.1 Motivation 1.2 Zielsetzung 1.3 Methodisches Vorgehen und struktureller Aufbau der Arbeit 2 Theoretische Grundlagen 2.1 Festelektrolyt Yttriumoxid stabilisiertes ZrO2 (YSZ) 2.1.1 Strukturelle Aspekte 2.1.2 Elektronen- und Ionenleitung 2.2 Elektroden im Gleichgewicht und unter Stromfluss 2.2.1 Gleichgewichtselektrode 2.2.2 Elektroden unter Stromfluss 2.2.2.1 Ladungsdurchtritt und Transportprozesse 2.2.2.2 Co-limitierte Prozesse 2.2.2.3 Konzentrationslimitierendes Verhalten 2.3 Stabilität von Elektrodensystemen 2.3.1.1 Unterschiede von dichten und porösen Metall/ Cermet- Elektroden (morphologische Parameter) 2.3.1.2 Ursachen der Degradation 2.4 Elektrochemische Methodik zur Charakterisierung des Elektrodensystems 2.4.1 Zyklovoltammetrie 2.4.2 Elektrochemische Impedanzuntersuchung 3 Messtechnik und Experimentelles 3.1 Probenherstellung 3.1.1 Präparation und Zusammensetzung 3.1.2 Funktion 3.2 Messplätze für Elektroden- und Sensoruntersuchungen 3.2.1 Standardmessplatz 3.2.2 Messplatz zur Phosphorvergiftung 3.3 Vorbehandlung des Elektrodensystems 3.4 Degradation und Bewertung 3.4.1 Degradation durch SiO2 3.4.2 YSZ-Degradation durch Wasser 3.4.3 YSZ-Degradation durch Natriumionen 3.4.4 Elektrodendegradation durch Wasserdampf 3.4.5 Elektrodendegradation durch Phosphor 3.4.6 Regeneration 3.5 Charakterisierung des Elektrodenystems & Grenzen der Methodik 3.5.1 Analytische und bildgebende Verfahren 3.5.2 Elektrochemische Verfahren 4 Experimentelle Ergebnisse und Diskussion 4.1 Morphologie der Elektrodensysteme 4.1.1 Festelektrolyt 4.1.1.1 Einfluss von Siliciumdioxid 4.1.1.2 Einfluss von Natriumionen 4.1.1.3 Zusammenfassung Festelektrolyt 4.1.2 Poröse Cermet-Elektrode 4.1.2.1 Elektrodenstruktur 4.1.2.2 Elementare Elektrodenprozesse 4.1.2.3 Niedertemperaturverhalten 4.1.2.4 Zusammenfassung der Resultate, gewonnen an der porösen Cermet-Elektrode 4.2 Degradation der Elektrodensysteme 4.2.1 Einfluss von Siliziumdioxid 4.2.2 Einfluss von Wasserdampf 4.2.2.1 Motivation 4.2.2.2 Festelektrolyt 4.2.2.3 Alterung von Cermet-Elektroden in Wasserdampfhaltigen Gasen 4.2.2.4 Elektrochemisch provozierte Reaktionen 4.2.2.5 Degradationsmechanismen 4.2.2.6 Zusammenfassung H2O 4.2.3 Einfluss von Phosphorpentoxid 4.2.3.1 Elektrochemisch provozierte Reaktion 4.2.3.2 Degradationsmechanismen 4.2.3.3 Zusammenfassung P2O5 5 Zusammenfassung und Ausblick
8

On the effect of secondary phases on gasifier slag behavior

Schwitalla, Daniel 09 March 2022 (has links)
By analyzing process samples full and pilot scale gasifiers, the main influences affecting their slag are identified. Based on this knowledge as well as the current literature, the effect of crystallization was identified as crucial for understanding slag behavior and is analyzed during cooldown. Finally, the emerging interest in sewage sludge upcycling via gasification necessitated an investigation on the influence of adding P2O5 as slag constituent. All conclusions concerning the full scale gasifier slags were based on XRF, XRD, and SEM-EDX analyses coupled with thermodynamic equilibrium calculations via FactSage. The subsequently presented research on crystallization and the effect of P2O5 was centered on conducting slag viscosity measurements, recreating the conditions of said measurement in a quench oven, and analyzing the resulting quench samples via the mentioned analysis methods. Special focus was put on the phase evolution, its governing factors, and the effect on slag viscosity.:1. INTRODUCTION 1 2. FUNDAMENTALS IN SLAG BEHAVIOR CHARACTERIZATION 3 2.1. BASE TO ACID RATIO AS KEY FIGURE FOR SLAG CHARACTERIZATION 7 2.2. VISCOSITY ALTERING SECONDARY PHASES IN SLAGS 9 2.2.1. The effect of crystallization on slag flow 10 2.2.2. Modelling and measuring crystallization in slags 11 2.3. CRITICAL VISCOSITY 13 2.4. PHOSPHOROUS OXIDE IN SLAGS 15 2.4.1. Behavior of P2O5 within slags 16 2.4.2. Phase separation in melts containing P2O5 17 2.4.3. Effect on slag viscosity 22 3. ANALYTICAL METHODS 26 3.1. SAMPLE PRETREATMENT 26 3.2. ASH FUSION TEMPERATURE 28 3.3. X-RAY FLUORESCENCE MEASUREMENT (XRF) 30 3.4. X-RAY DIFFRACTION 31 3.5. VISCOSITY MEASUREMENT 32 3.6. DIFFERENTIAL THERMAL ANALYSIS (DTA) 36 3.7. QUENCH APPARATUS 37 3.8. SEM-EDX 39 3.9. THERMODYNAMIC EQUILIBRIUM CALCULATIONS 40 4. CHARACTERIZATION OF SLAGS FROM FULL OR PILOT SCALE GASIFIERS 42 4.1. SLAG FROM GENERAL ELECTRICS GASIFIER IN TAMPA 43 4.1.1. Analysis of the suspending main phase 45 4.1.2. Analysis of the silica phase 50 4.1.3. Analysis of the metal enclosures 51 4.1.4. Analysis of the vanadium-rich particles 53 4.1.5. Summary of the analysis of the General Electrics gasifier slag 55 4.2. SLAG FROM GSP GASIFIER 57 4.2.1. NCPP slag 57 4.2.2. Huainan Anhui slag 64 4.2.3. Genesee slag 70 4.2.4. Hambach-Garzweiler 50:50 slag 75 4.2.5. Summary of the analysis of the GSP slags 86 4.3. SLAG FROM BRITISH GAS/LURGI (BGL) GASIFIER 88 4.3.1. Summary and conclusions of the analysis of the BGL slag 99 5. CHARACTERIZING CRYSTALLIZATION DURING SLAG VISCOSITY MEASUREMENTS 102 5.1. EXPERIMENTAL PROCEDURE 103 5.1.1. Sample preparation 107 5.1.2. Viscosity measurement 108 5.1.3. Differential thermal analysis (DTA) 108 5.1.4. Quench oven 108 5.1.5. XRD, XRF, SEM-EDX, and FactSage calculations 109 5.2. RESULTS AND DISCUSSION 109 5.2.1. Slag 1 (CO/CO2 atmosphere) 110 5.2.2. Slag 2 (CO/CO2 atmosphere) 112 5.2.3. Slag 3 (air atmosphere) 116 5.2.4. Slag 3 (CO/CO2 atmosphere) 119 5.3. CONCLUSION AND SUMMARY OF THE STUDY OF CRYSTALLIZATION IN SLAGS DURING COOLDOWN 122 6. THE EFFECT OF PHOSPHOROUS OXIDE ON SLAGS 125 6.1. PRELIMINARY SEWAGE SLUDGE SLAG INVESTIGATION 126 6.1.1. Conclusion and summary sewage slag investigation 136 6.2. EXPERIMENTAL PROCEDURE FOR PARAMETRIC STUDY 139 6.3. PARAMETRIC STUDY 141 6.3.1. HKN with 15% sand (HKNS) 142 6.3.2. HKNS with low P2O5 addition (HKNS5P) 147 6.3.3. HKNS with medium low P2O5 addition (HKNS10P) 153 6.3.4. HKNS with medium high P2O5 addition (HKNS15P) 158 6.3.5. HKNS with high P2O5 addition (HKNS20P) 163 6.3.6. P2O5 distribution 169 6.3.7. Effect of P2O5 on viscosity 174 6.4. SUMMARY ON THE INVESTIGATION OF P2O5 IN SLAGS 179 7. CONCLUSION AND OUTLOOK 185 8. REFERENCES 190 9. APPENDIX A: DIFFERENCE IN PREDICTION OF SEWAGE SLUDGE ELEMENTAL DISTRIBUTION 213 10. APPENDIX B COMPARISON OF XRF ANALYSES OF HKNS-P2O5 MIXTURES 215 11. APPENDIX C EDX MAPS OF THE QUENCH SAMPLES IN THE PARAMETRIC PHOSPHORUS ADDITION STUDY 218 12. APPENDIX D SUMMARY OF PHASE COMPOSITION OF THE EDX MAPS 239 13. APPENDIX E ENRICHMENT FACTORS FOR THE QUENCH SAMPLES IN THE PARAMETRIC PHOSPHORUS ADDITION STUDY 242
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Structure And Electrical Transport Studies Of Lithium Ion Conducting Glasses

Ganguli, Munia 11 1900 (has links) (PDF)
No description available.
10

Unmixing of Phosphorus-bearing Melts on Earth and Mars

Busche, Tamara Miranda 26 March 2019 (has links)
No description available.

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