Dissertations / Theses on the topic 'NO and SO2 elimination'
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Salem, Ibtissam. "Elimination des NOx issus de sources fixes : réduction par les hydrocarbures en C3 en présence de SO2." Poitiers, 2005. http://www.theses.fr/2005POIT2275.
Full textIn the present work the NOx reduction with C3 hydrocarbons has been examined. The objective is to study the influence of SO2 on metal based catalysts with an oxygen excess in the presence of CO2 and H2O, in a temperature range from 200 to 400 °C. The NOx are totally converted under stoechiometric conditions in the absence of sulfur dioxide and the most sulfur resistant catalyst is Pt/ZrAl. A series of different metals (Pt, Pd, Rh, Ag, Ir, Sn ) supported on several oxides (Al, , K-Al, Ce-Al, Ti-Al, Zr-Al, Ce-Zr, Si, C) were tested for NOx reduction with 1000 ppm propylene and the Pt/ZrAl was found to be the most active catalyst. The sulfation of the catalysts, generally leads to an increase of their activity in the presence of SO2, and conversely to a decrease of the N2O selectivity. Finally, the NO consumption has been observed in both the presence and the absence of propane. This phenomenon has been associated with the nitric acid formation via NO oxidation and not with NOx reduction
Chippaux, Jean-Philippe. "La dracunculose en savane arboree au benin. Etudes systematique, epidemiologique et moyens a mettre en oeuvre pour son elimination." Paris 6, 1991. http://www.theses.fr/1991PA066443.
Full textYan, Yige. "TiO2 photocatalysts prepared via a sol-gel route assisted by P- and F- containing additives : applications to the degradation of MEK and to the elimination of bacteria on surfaces." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF063/document.
Full textThe objective of this work consists in synthesizing TiO2 nanomaterials designed for the degradation of VOCs and for the elimination of bacteria on surface. Firstly, based on a synthesis of a BmimPF6-ionic liquid-derived TiO2 material through a modified sol-gel route, the roles of two constituent elements of BmimPF6 (P and F) have been investigated by replacing BmimPF6 with P- and F- contained additives. Comparing to the reference P25 and additive-free-derived TiO2 materials, P-derived TiO2 showed already well crystallized anatase phase before calcination and a high surface area along with a small mean crystal size even after calcinations. Those properties were similar to that synthesized with the presence of BmimPF6; while F-derived TiO2 crystals showed anisotropic shape during the aging step of the synthesis. Evaluation of the photocatalytic activity of the photocatalysts has been performed then. Compared to additive-free derived TiO2 and the TiO2 P25, P- and F- derived TiO2 materials with low P and F content (“PANaF”) showed higher activity under UVA in terms of gas-phase degradation of a model VOC, Methl Ethyl Ketone (MEK). The same material also showed higher surface anti-bacterial activity under UVA in liquid against several strains of different bacterial species over that of P25. A correlation between the high photocatalytic performances with the material properties for “PANaF” TiO2 materials was finally proposed. The influences of the presence of bulk or surface PO43-, dissolved O2 concentration and surface topology on photocatalytic activity were also discussed. The cheap replacement additives used and the resulted high activity of “PANaF” TiO2 nanomaterials presents interest for industrial elaboration
Ould, Mohamdi El Khalil. "Elimination réduite." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13182.
Full textOuld, Mohamdi El Khalil. "Elimination réduite." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376172344.
Full textAnton, Peter, and André Laschewsky. "Polysoaps via alternating olefin/SO2 copolymers." Universität Potsdam, 1991. http://opus.kobv.de/ubp/volltexte/2008/1721/.
Full textSouza, Ana Carolina Bello de. "Estudo te?rico das rea??es de SN2 em fase gasosa: RCI+OH??ROH+CI? (R = Metil, Etil, n-Propil, i-Propil, n- Butil, s-Butil e t-Butil)." Universidade Federal Rural do Rio de Janeiro, 2012. https://tede.ufrrj.br/jspui/handle/jspui/1547.
Full textMade available in DSpace on 2017-04-24T14:13:26Z (GMT). No. of bitstreams: 1 2012 - Ana Carolina Bello de Souza.pdf: 1911170 bytes, checksum: 62c70571aeb2100b8313dc1ef44eac2b (MD5) Previous issue date: 2012-10-03
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
In this work, the theoretical study of the gas-phase bimolecular nucleophilic substitution reaction, CH3Cl + OH- CH3OH + Cl-, is introduced, aiming the description of the potential energy surface, the calculation of rate constants and the investigation of the effect of increasing the side chain (changing the CH3 radical in the reaction cited above by the radicals ethyl, n-propyl, i-propyl, n-butyl, s-butyl e t-butyl). The theoretical calculations have been first performed at the MP2/6-31+G(d) level for the geometry optimizations and vibrational frequencies calculations. Single point calculations at the CCSD(T)/6-31+G(d) level have also been performed in order to improve the total energies for the stationary points. However, the relative energies of these stationary points at both MP2 and CCSD(T) level shown close results, so that the single point calculations at the CCSD(T) level have not been proved strictly necessary and have therefore not been performed for all the points along the potential energy surface. The minimum energy path has been described by the intrinsic reaction coordinate method, calculated at the MP2/6-31+G(d) by performing sequential geometry optimizations starting from the saddle point. The calculated enthalpy difference at 298K for the reaction has been determined as -49.5 kcal/mol, in good agreement with the literature value: -50.5 kcal/mol. The calculated rate constant has been obtained as 1.41 x 10-9 cm3.molecule-1.s-1, at 298,15K, in excellent agreement with the experimental data: 1.3 ? 1.6 x 10-9 cm3.molecule-1.s-1.Moreover, the rate constants show non-Arrhenius behavior, decreasing as the temperature increases, which is consistent with the experimental expectation. In this way, the performance of the variational transition state theory for this reaction can be considered satisfactory. By increasing the side chain of the reactant, other reaction channels have been observed: the bimolecular elimination E2 channel and the attack of the nucleophile from the same plane of the exit group (the front-SN2).For these reactions of the alkyl chlorides on n carbon atoms (1 < n ? 4), the B3LYP/6-31+G(d,p) level has been adopted for geometry optimizations and vibrational frequencies. Then, single point calculations at the CCSD(T)/6-31+G(d,p)//B3LYP/6- 31+G(d,p) level have been performed. A comparison of the reaction channels, back- SN2 and E2, shows that the E2 channel is kinetically favored, whereas the SN2 products are thermodynamically more stable. As expected, high values for the potential height have been observed for the front-SN2, being these channels disfavored in all cases. In general, the energy of the saddle points in respect to the isolated reactants slightly depend upon the size of the side chain.
Este trabalho trata do estudo te?rico das rea??es de substitui??o nucleof?lica de segunda ordem, CH3Cl + OH- CH3OH + Cl-, em fase gasosa, visando estudar a superf?cie de energia potencial, obter as constantes de velocidade e ainda verificando o efeito do aumento da cadeia lateral (trocando o radical CH3 na rea??o descrita acima por radicais etil, n-propil, i-propil, n-butil, s-butil e t-butil). Primeiramente, c?lculos te?ricos para otimiza??es de geometria e frequ?ncia foram realizados em n?vel MP2/6-31+G(d) para a rea??o CH3Cl + OH- CH3OH + Cl- e, em seguida, c?lculos single-point em n?vel CCSD(T)/6-31+G(d) foram realizados para corrigir os valores da energia eletr?nica dos pontos estacion?rios obtidos no caminho de rea??o. Entretanto, os valores obtidos para as energias relativas em n?veis MP2 e CCSD(T) foram muito pr?ximos, n?o sendo estritamente necess?rio refinar,atrav?s de c?lculos single-point em n?vel CCSD(T)/6- 31+G(d),os valores de energia de todos os pontos obtidos na superf?cie de energia potencial. O caminho de rea??o menor energia foi descrito pela coordenada de rea??o intr?nseca, calculada por otimiza??es de geometrias de uma sequ?ncia de configura??es ao redor do ponto de sela em n?vel MP2/6-31+G(d). A diferen?a de entalpia a 298K calculada para a rea??o foi de -49,5 kcal/mol, em bom acordo com o dado da literatura, -50,5 kcal/mol. A constante de velocidade da rea??o obtida foi de 1,41 x 10-9 cm3.mol?cula-1.s-1, a 298,15K, em excelente acordo com o dado experimental: 1,3 ? 1,6 x 10-9 cm3.mol?cula-1.s-1. Al?m disso, as constantes de velocidade globais apresentam comportamento n?o-Arrhenius, diminuindo conforme a temperatura aumenta, em um perfil consistente com a observa??o experimental. Dessa forma, a aplica??o da teoria de estado de transi??o se mostra satisfat?ria para essa rea??o. A partir do aumento da cadeia lateral, outros canais de rea??o foram observados, em prov?vel competi??o ? substitui??o nucleof?lica de ordem 2: a elimina??o de segunda ordem, E2. O ataque do nucle?filo pela frente da cadeia tamb?m foi obtido e investigado. Para as rea??es dos cloretos de alquila com cadeia lateral de n carbonos (1 < n ? 4), o n?vel B3LYP/6- 31+G(d,p) foi adotado para c?lculos de otimiza??es e frequ?ncias. Posteriormente, c?lculos em n?vel CCSD(T)/6-31+G(d,p)//B3LYP/6-31+G(d,p) foram realizados. Comparando os canais de rea??o de substitui??o nucleof?lica back e de elimina??o, o canal cineticamente favorecido foi o de elimina??o, por?m os produtos termodinamicamente mais est?veis s?o os de substitui??o nucleof?lica. Como esperado, observa-se uma barreira de potencial muito alta para as rea??es substitui??o pela frente, sendo esses canais desfavorecidos em todos os casos.Em geral, a diferen?a de energia dos pontos de sela em rela??o aos reagentes isolados mostra pequena depend?ncia com o aumento da cadeia lateral linear
Fernández, Gómez Manuel. "Binary Redundancy Elimination." Doctoral thesis, Universitat Politècnica de Catalunya, 2005. http://hdl.handle.net/10803/5985.
Full textPor otro lado, las optimizaciones aplicadas en tiempo de enlace o directamente al programa ejecutable final han recibido una atención creciente en los últimos años, debido a limitaciones existentes en el modelo de compilación tradicional. Incluso aplicando sofisticados análisis y transformaciones interprocedurales, un compilador tradicional no es capaz de optimizar un programa como una entidad completa. Un problema similar aparece aplicando técnicas de compilación dirigidas por profiling: grandes proyectos se ven forzados a recompilar todos y cada uno de sus módulos para aprovechar dicha información. Por el contrario, seria más conveniente construir la aplicación completa, instrumentarla para obtener información de profiling y optimizar entonces el binario final sin recompilar ni un solo fichero fuente.
En esta tesis presentamos nuevas técnicas de compilación dirigidas por profiling para eliminar la redundancia encontrada en programas ejecutables a nivel binario (esto es, redundancia binaria), incluso aunque estos programas hayan sido compilados agresivamente con un novísimo compilador comercial. Nuestras técnicas de eliminación de redundancia están diseñadas para eliminar operaciones de memoria y de salto redundantes, que son las más importantes para mitigar los problemas de rendimiento que hemos mencionado. Estas propuestas están basadas en técnicas de eliminación de redundancia parcial sensibles al camino de ejecución. Los resultados muestran que aplicando nuestras optimizaciones, somos capaces de alcanzar una reducción del 14% en el tiempo de ejecución de nuestro conjunto de programas.
En este trabajo también revisamos el problemas del análisis de alias en programas ejecutables, identificando el por qué la desambiguación de memoria es uno de los puntos débiles en la modificación de código objeto. Proponemos varios análisis para ser aplicados en el contexto de optimizadores binarios. Primero un análisis de alias estricto para descubrir dependencias de memoria sensibles al camino de ejecución, el cual es usado en nuestras optimizaciones para la eliminación de redundancias de memoria.
Seguidamente, dos análisis especulativos de posibles alias para detección de independencias de memoria. Estos análisis están basados en introducir información especulativa en tiempo de análisis, lo que incrementa la precisión en partes importantes de código manteniendo el análisis eficiente. Los resultados muestran que nuestras propuestas son altamente útiles para incrementar la desambiguación de memoria de código binario, lo que se traduce en oportunidades para aplicar optimizaciones.
Todos nuestros algoritmos, tanto de análisis como de optimización, han sido implementados en un optimizador binario, enfatizando los problemas más relevantes en la aplicaciones de nuestros algoritmos en código ejecutable, sin la ayuda de gran parte de la información de alto nivel presente en compiladores tradicionales.
Two of the most important performance limiters in today's processor families comes from solving the memory wall and handling control dependencies. In order to address these issues, cache memories and branch predictors are well-known hardware proposals that take advantage of, among other things, exploiting both temporal memory reuse and branch correlation. In other words, they try to exploit the dynamic redundancy existing in programs. This redundancy comes partly from the way that programmers write source code, but also from limitations in the compilation model of traditional compilers, which introduces unnecessary memory and conditional branch instructions. We believe that today's optimizing compilers should be very aggressive in optimizing programs, and then they should be expected to optimize a significant part of this redundancy away.
On the other hand, optimizations performed at link-time or directly applied to final program executables have received increased attention in recent years, due to limitations in the traditional compilation model. First, even though performing sophisticated interprocedural analyses and transformations, traditional compilers do not have the opportunity to optimize the program as a whole. A similar problem arises when applying profile-directe compilation techniques: large projects will be forced to re-build every source file to take advantage of profile information. By contrast, it would be more convenient to build the full application, instrument it to obtain profile data and then re-optimize the final binary without recompiling a single source file.
In this thesis we present new profile-guided compiler optimizations for eliminating the redundancy encountered on executable programs at binary level (i.e.: binary redundancy), even though these programs have been compiled with full optimizations using a state-ofthe- art commercial compiler. In particular, our Binary Redundancy Elimination (BRE) techniques are targeted at eliminating both redundant memory operations and redundant conditional branches, which are the most important ones for addressing the performance issues that we mentioned above in today's microprocessors. These new proposals are mainly based on Partial Redundancy Elimination (PRE) techniques for eliminating partial redundancies in a path-sensitive fashion. Our results show that, by applying our optimizations, we are able to achieve a 14% execution time reduction in our benchmark suite.
In this work we also review the problem of alias analysis at the executable program level, identifying why memory disambiguation is one of the weak points of object code modification. We then propose several alias analyses to be applied in the context of linktime or executable code optimizers. First, we present a must-alias analysis to recognize memory dependencies in a path- sensitive fashion, which is used in our optimization for eliminating redundant memory operations. Next, we propose two speculative may-alias data-flow algorithms to recognize memory independencies. These may-alias analyses are based on introducing unsafe speculation at analysis time, which increases alias precision on important portions of code while keeping the analysis reasonably cost-efficient. Our results show that our analyses prove to be very useful for increasing memory disambiguation accuracy of binary code, which turns out into opportunities for applying optimizations.
All our algorithms, both for the analyses and the optimizations, have been implemented within a binary optimizer, which overcomes most of the existing limitations of traditional source-code compilers. Therefore, our work also points out the most relevant issues of applying our algorithms at the executable code level, since most of the high-level information available in traditional compilers is lost.
Seidler, Torsten. "Minderung rohmaterialbedingter SO2-Emissionen in der Zementindustrie /." Düsseldorf : Verl. Bau und Technik, 2006. http://www.agi-imc.de/intelligentSEARCH.nsf/alldocs/6884DFF6B3D69539C12571E0003774AD/$File/000000016401889.PDF?OpenElement.
Full textZhang, Wensheng. "SO2/O2 as an oxidant in hydrometallurgy." Thesis, Zhang, Wensheng (2000) SO2/O2 as an oxidant in hydrometallurgy. PhD thesis, Murdoch University, 2000. https://researchrepository.murdoch.edu.au/id/eprint/458/.
Full textZhang, Wensheng. "SO2/O2 as an oxidant in hydrometallurgy." Murdoch University, 2000. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20080115.141151.
Full textCai, Qiong Computer Science & Engineering Faculty of Engineering UNSW. "Profile-guided redundancy elimination." Awarded by:University of New South Wales. School of Computer Science and Engineering, 2006. http://handle.unsw.edu.au/1959.4/25156.
Full textHerold, F. W., and J. A. Kaiser. "ELIMINATION OF SIDELOBE RESPONSE." International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607377.
Full textConventional phased arrays nominally sum the signals received by the elements prior to detection. By multiplying rather than summing signals received from pairs of elements, i.e., interferometer pairs, a set of Spatial Frequencies (SFs) is obtained. Obtaining the SFs requires employment of a multiple local oscillator technique. When summed, these spatial frequencies produce a single lobed (voltage) radiation pattern which, when passed through a biased detector, removes all sidelobes from the response at a small loss of desired signal power.
Ramírez, Torres Dulce María. "Interfase líquido-vapor del óxido de azufre (SO2)." Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2017. http://hdl.handle.net/20.500.11799/68451.
Full textEl dioxido de azufre es una molécula compuesta por un atomo de azufre y dos atomos de oxígeno con formula molecular SO2 es un gas incoloro con un olor irritante característico que generalmente se percibe entre 0.3-1.4 ppm (partes por millón). Esta molécula no es inflamable tampoco explosivo y es relativamente estable. Su densidad es más del doble que la del aire ambiental, y es altamente soluble en agua formando disoluciones acidas. En contacto con membranas húmedas el SO2 forma acido sulfúrico H2 SO4 , que es responsable de fuertes irritaciones en los ojos, membranas mucosas y piel.
Ribeiro, Catarina da Silva Espada. "Redimensionamento de uma torre de absorção de SO2." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11644.
Full textEste trabalho consiste no estudo da Torre de Absorção de SO2 da empresa Soporcel, a qual se encontra com um funcionamento irregular. Com este estudo pretende-se que a coluna passe a funcionar corretamente, garantindo que as emissões deste soluto se encontram dentro dos limites exigidos pela legislação ambiental em vigor. A análise preliminar do processo foi fundamentada pelos dados facultados pela empresa, tendo-se verificado que apresenta problemas ao nível do humedecimento, os quais justificam o mau funcionamento desta. Além do estudo da torre real, o trabalho apresenta sugestões para superar o problema aproveitando o mesmo equipamento, assim como projeta uma nova torre de absorção.
This work comprises a study of a SO2 absorption tower that has not been working properly at Soporcel factory. The study aims at correcting the tower irregular operation and assuring that the solute emissions are within the limits imposed by current environmental laws. The preliminary analysis of the process based on data from Soporcel revealed problems at wetting level, which can justify the inefficient separation detected on the equipment. In addition to the evaluation of the existing tower, this work presents suggestions to overcome the current problems whether by maintaining the same equipment structure or through a project of a new tower.
Gonçalves, Catarina Salvador. "Remoção de SO2 por cinzas volantes de biomassa." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/15584.
Full textOs óxidos de enxofre (SOx) são conhecidos por constituírem uma importante fonte de poluição atmosférica, sendo precursores da formação de nevoeiro ácido e chuvas ácidas. Esta categoria de poluentes afeta também a saúde humana, estando associada ao aumento de doenças respiratórias, de morbidez e de mortalidade. Por estes motivos, a União Europeia e muitos países têm aprovado regulamentação cada vez mais restrita para as emissões atmosféricas dos referidos compostos. Dependendo do tipo de combustível e de instalação de combustão, o controlo das emissões de SOx pode ser feito numa das três etapas: na pré-combustão, na combustão (chama) e na pós-combustão. Sendo que a maioria das tecnologias de controlo destas emissões têm aplicação na etapa pós-combustão, i.e. no tratamento de gases de combustão. O método mais usado para remover SOx dos gases de combustão é através da sua adsorção por óxidos metálicos. Este tipo de processo de dessulfurização possui duas vias: a seca e a húmida. Apesar do relativo baixo custo de operação e da elevada eficiência, qualquer uma destas vias convencionais apresenta desvantagens (elevados consumo de água com o consequente elevado volume de efluentes líquidos a tratar, elevada produção de gesso como subproduto, etc.). Este facto tem motivado a comunidade científica, desde há quase duas décadas, a investigar métodos alternativos que ultrapassem as desvantagens dos convencionais. Neste contexto, este trabalho surge com o principal objetivo de desenvolver sorventes, à base de cinzas volantes da queima de biomassa, com vista à remoção de SO2 de efluentes gasosos. Deste modo, valoriza-se também um resíduo sólido com crescente produção em Portugal. Na componente experimental do trabalho foram usados duas variedades de cinzas volantes de biomassa (“B” e “C”) para a preparação de sorventes com água e várias razões mássicas de hidróxido de cálcio. De todos os sorventes foram preparados grânulos tendo em vista uma posterior aplicação industrial e facilidade de manuseamento. Os sorventes foram caracterizados em termos do teor em metais alcalino e alcalino-terrosos (sendo o metal mais abundante o cálcio), valor neutralizante, pH e composição mineralógica por difração de raios-X (DRX). Os sorventes em pó e em grânulos foram testados em ensaios de dessulfurização, num reator contínuo de leito fixo, de um efluente gasoso sintético, à temperatura ambiente com uma mistura de 1000ppm SO2 e árgon. Destes ensaios selecionou-se o sorvente que apresentou maior capacidade de remoção de SO2, um à base de cinza “C”. Com este sorvente foram realizados mais ensaios com vista a avaliar o efeito da temperatura (150º C, 220º C e 300º C) e da concentração de SO2 (500ppm e 1000ppm) na eficiência de remoção do SO2. Conclui-se que a temperatura tem um efeito negativo dos 25º C para os 150º C (como era expectável, porque os processos de adsorção são exotérmicos); no entanto dos 150º C para os 220º C dá-se um ligeiro aumento e desta para os 300º C um aumento ainda maior, e o da concentração de SO2 é positivo, i.e. com o aumento da concentração de SO2 no gás há um favorecimento da cinética de adsorção.Este sorvente com melhor desempenho na remoção de SO2 foi analisado por DRX antes e depois de ter sido testado no reator de leito fixo, onde os elementos quartzo (syn-SiO2), calcite (syn-CaCO3) e portlandite (syn-Ca(OH)2) se enalteceram por estarem presentes em quantidades superiores nas 2 amostras. Também se determinou o pH e valor neutralizante de todos os sorventes depois dos ensaios de dessulfurização, registando-se uma diminuição de ambos os parâmetros relativamente aos valores iniciais. Porém, qualquer um destes parâmetros revelou-se inadequado para a monitorização (de forma indireta) do grau de dessulfurização conseguido num ensaio.
Sulfur oxides (SOx) are known to constitute a major source of air pollution, acid precursors to the formation of fog and acid rain. This category of pollutants also affects human health and is associated with increases in respiratory diseases, morbidity and mortality. For these reasons, the European Union and many countries have adopted regulations increasingly restricted for air emissions of these compounds. Depending on the type of fuel and combustion plant, the control of SOx emissions can be done in one of three stages: pre-combustion, combustion (flame) and post-combustion. Most of these emissions control technologies have application in the post-combustion step, corresponding to the the flue gases treatment. The method most commonly used to remove SOx from the flue gas is through adsorption by metallic oxides. This type of desulfurization process has two routes: the dry and the wet. Despite of the relatively low cost of operation and high efficiency, any of these conventional routes have disadvantages (high water consumption with consequent high volume of wastewater to be treated, high production of gypsum as a byproduct, etc.). This has motivated the scientific community, for almost two decades, to investigate alternative methods to overcome the drawbacks of conventional. In this context, this work arises with the main goal to develop sorbents, based on fly ash from biomass combustion, for the removal of SO2 from gaseous effluents. By this wayone also recover a solid waste with growing production in Portugal. For the experimental work component it was used two types of fly ash from biomass ("B" and "C") for the preparation of sorbents in water and various weight ratios of calcium hydroxide. It was prepared granules from all sorbent with foreseeing a later industrial application and ease of handling. The sorbents were characterized in terms of the content of alkali and terrous-alkalin metals (being the calcium the most abundant metal) neutralizing value, pH and mineral composition by X-ray diffraction (XRD). The sorbent powder and granules were tested in desulfurization essays in a continuous fixed bed reactor, of a synthetic flue gas at room temperature with a mixture of 1000 ppm of SO2 and argon. From these trials was selected the sorbent that showed the highest SO2 removal performance, a "C" fly ash based. With this sorbent it was carried out more essays in order to assess the effect of temperature (150° C, 220° C and 300° C) and SO2 concentration (500ppm and 1000ppm) on the SO2 removal efficiency. It was conclude that temperature has a negative effect from 25° C to 150° C (as expected, because the adsorption processes are exothermic); however from 150º C to 220º C it happens a slight increase and to 300º C a bigger increase, and the SO2 concentration is positive, this is with increasing concentration of SO2 in the gas there is a favoring favoring kinetic adsorption. This sorbent with better performance in SO2 removal was analyzed by XRD before and after being tested in a fixed bed reactor, where the elements quartz (syn-SiO2), calcite (syn-CaCO3) and portlandite (syn-Ca(OH)2) were highlighted for being present in higher amounts in the two samples. It was also determined the pH and neutralizing value of all sorbents after the desulfurization tests, registering a decrease of both parameters compared to the initial values. However, any of these parameters were proved inadequate for monitoring (indirectly) the degree of desulfurization achieved in a test.
Tesař, Jan. "Snížení emisí SO2 ve spalinách z fluidního kotle." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241676.
Full textWernhard, Christoph. "Automated deduction for projection elimination /." Heidelberg : AKA, 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?u20=9783898383240.
Full textSankar, Arvind 1976. "Smoothed analysis of Gaussian elimination." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28311.
Full textIncludes bibliographical references (p. 59-60).
We present a smoothed analysis of Gaussian elimination, both with partial pivoting and without pivoting. Let A be any matrix and let A be a slight random perturbation of A. We prove that it is unlikely that A has large condition number. Using this result, we prove it is unlikely that A has large growth factor under Gaussian elimination without pivoting. By combining these results, we bound the smoothed precision needed to perform Gaussian elimination without pivoting. Our results improve the average-case analysis of Gaussian elimination without pivoting performed by Yeung and Chan (SIAM J. Matrix Anal. Appl., 1997). We then extend the result on the growth factor to the case of partial pivoting, and present the first analysis of partial pivoting that gives a sub-exponential bound on the growth factor. In particular, we show that if the random perturbation is Gaussian with variance [sigma]², then the growth factor is bounded by (n/[sigma])[to the power of] (o log n) with very high probability.
by Arvind Sankar.
Ph.D.
Budd, Chris. "Data Protection and Data Elimination." International Foundation for Telemetering, 2015. http://hdl.handle.net/10150/596395.
Full textData security is becoming increasingly important in all areas of storage. The news services frequently have stories about lost or stolen storage devices and the panic it causes. Data security in an SSD usually involves two components: data protection and data elimination. Data protection includes passwords to protect against unauthorized access and encryption to protect against recovering data from the flash chips. Data elimination includes erasing the encryption key and erasing the flash. Telemetry applications frequently add requirements such as write protection, external erase triggers, and overwriting the flash after the erase. This presentation will review these data security features.
Arnaudiès, Jean-Marie. "Elimination et theorie de galois." Toulouse 3, 1989. http://www.theses.fr/1989TOU30090.
Full textVizcaíno, Pedro Francisco Valencia. "Some uses of cut elimination." Thesis, University of Leeds, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.713880.
Full textYang, Shuo. "Ammonia elimination from protonated nucleobases." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/4977.
Full textThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on May 27, 2009) Typescript. Includes bibliographical references.
Liu, Yanping. "Elimination de nanoparticules d'effluents liquides." Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0030/document.
Full textThe objective of this work is to develop a technique for separating nanoparticles from liquid media. The literature has shown the potential hazard of nanoparticules and a large quantity of the nanosilica release has been entering in water resources. Tests flotation separations are carried out without additive, in the presence of AlCl3, CTAB, and trying to change the surface charge of the bubbles. These tests are not very conclusive. Flotation has been observed, but only when the additive has led to the formation of flocs which have themselves been floated. The results of tests with additives showed that the interaction between heterocoagulation (flotation) and homocoagulation is very important, leading to the study of coagulation under the effect of AlCl3 and CTAB. The results revealed complex mechanisms of coagulation, because the particle size plays an important role. For each observed phenomenon, a mechanism has been proposed, trying to link the observations to modeling mechanisms of aggregation. From the standpoint of the separation process, coagulation followed by sedimentation to separate the silica nanoparticles with remarkable efficiency (decrease of 99% of the turbidity)
Jung, Sebastian. "Erzeugung kalter SO2-Moleküle zur Untersuchung ihrer schwellnahen Photodissoziation." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981930190.
Full textBär, Jaciara. "Absorção de SO2 por líquidos iônicos: efeito do ânion." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-18082016-085659/.
Full textSulfur dioxide (SO2) is one of the main atmospheric pollutants and the search for systems capable of absorbing detect and/or quantify such gas has been of great interest. In this context, ionic liquids (IL) have shown potential application in capture methodologies and gas storage. In this study, our interest consists in the understanding of the main factors that govern the interactions between SO2 and diferents ions of ionic liquids. In particular, the charge transfer specific interaction was explored between anions (Lewis base) and SO2 (Lewis acid). The approach of this study was based on a systematic investigation of LI formed by 1-butyl cation, 3-methylimidazolium (BMI) and different anions, using vibrational spectroscopy (Raman and IR), especially resonance Raman spectroscopy, allied with theoretical calculations based on density functional theory (DFT). The vibrational spectroscopic results (Raman and IR) showed changes in the position and shape of the band assigned to the symmetric stretching mode vs(SO2) depending on the anion and SO2 concentration in LI. There were significant shifts to lower wavenumbers with respect to pure liquid SO2 (1145 cm-1) at lower SO2 concentrations in IL. In the series of halides, Cl-, Br- and I-, the bigger the anion, the larger the displacement (1138, 1133 and 1123 cm-1, respectively at 0.5 mole fraction). In the case of thiocyanate, regarded as a pseudo-halide, the band vs(SO2) appears at about 1130 cm-1 at the same molar fraction, i.e. at an intermediate value between the Br- and I-. The observed displacement can be interpreted accordingly to the specific interaction of charge transfer from the anion to SO2. A result that is worth mentioning is the dependence of the wavenumber of the Raman band vs(SO2) with the energy of the exciting radiation, which is called Raman scattering. This phenomenon could be explained using the model of \"solvation state selective excitation\" in which was possible to characterize the diferente solvation states of the SO2 in ionic liquids
Zhang, Ping. "SO2 Adsorption an Aktivkohle mit geringer Konzentration in Luft." Aachen Shaker, 2008. http://d-nb.info/992012538/04.
Full textKurenko, Landin Roman, and Balwan Rana. "The Atmospheric SO2 Distribution and Volcanic Activity on Io." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254261.
Full textBruggeman, Karla E. "The effects of elimination and non-elimination games on physical activity and psychosocial responses in children." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/747.
Full textSchwöbel, Frank. "Execution and elimination of apoptotic cells." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965885003.
Full textLakhal, Anen [Verfasser]. "Elimination in Operator Algebras / Anen Lakhal." Kassel : Universitätsbibliothek Kassel, 2014. http://d-nb.info/1059428962/34.
Full textBlack, John Adrian. "Incorrigibility and elimination : a mentalist response." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26960.
Full textArts, Faculty of
Philosophy, Department of
Graduate
Amyes, T. L. "Mechanisms of carboxyl-activated elimination reactions." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383698.
Full textBell, Kathryn Emma. "Advances in the retro-Cope elimination." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307744.
Full textCleator, Edward. "Applications of the reverse Cope elimination." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250235.
Full textBento, Inês Fernandes. "Centriole elimination in Drosophila melanogaster oogenesis." Doctoral thesis, Universidade Nova de Lisboa. Instituto de Tecnologia Química e Biológica, 2012. http://hdl.handle.net/10362/10588.
Full textThe centriole is a Eukaryotic organelle involved in a variety of processes. Within the cytoplasm the centriole is part of the centrosome, the major microtubule (MT) organizing center in animal cells. The centrosome is involved in the regulation of cell motility and polarity in interphase and the organization of the mitotic spindle in mitosis. Each centrosome is composed of two centrioles surrounded by a protein-rich matrix, the pericentriolar material (PCM) (reviewed by Bettencourt-Dias and Glover, 2007) .(...)
Chambrin, Hélène. "Elimination des déchets d'activités de soins." Paris 5, 1994. http://www.theses.fr/1994PA05P123.
Full textHong, Hoon. "Improvements in CAD-based quantifier elimination /." The Ohio State University, 1990. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487684245468432.
Full textIvashechkin, Pavel. "Elimination organischer Spurenstoffe aus kommunalem Abwasser." Aachen : Ges. zur Förderung der Siedlungswasserwirtschaft an der RWTH Aachen, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015644505&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full textEmiris, Ioannis Z. "Sparse elimination and applications in kinematics /." Berkeley, CA US : Univ. of California at Berkeley, 1994. http://www-sop.inria.fr/saga/personnel/Ioannis.Emiris/index.html.
Full textAzouit, Rémi. "Elimination adiabatique pour systèmes quantiques ouverts." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM008/document.
Full textThis thesis addresses the model reduction problem for open quantum systems with differenttime-scales, also called adiabatic elimination. The objective is to derive a generic adiabaticelimination technique preserving the quantum structure for the reduced model.We consider an open quantum system, described by a Lindblad master equation withtwo time-scales, where the fast time-scale drives the system towards an equilibrium state.The cases of a unique steady state and a manifold of steady states (decoherence-free space)are considered. The slow dynamics is treated as a perturbation. Using the time-scaleseparation, we developed a new adiabatic elimination technique to derive at any orderthe reduced model describing the slow variables. The method, based on an asymptoticexpansion and geometric singular perturbation theory, ensures the physical interpretationof the reduced second-order model by giving the reduced dynamics in a Lindblad formand the mapping defining the slow manifold as a completely positive trace-preserving map(Kraus map) form. We give explicit second-order formulas, to compute the reduced model,for composite systems with weak - Hamiltonian or cascade - coupling between the twosubsystems and preliminary results on the third order. For systems with decoherence-freespace, explicit second order formulas are as well derived
Jin, Hailiang. "Development of Polymeric SO2 Resistant Coating for Solid Amine Sorbent." University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1428180854.
Full textWu, Wai Man. "Statistical analysis on SO2, O3 and PM10 in Hong Kong /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?MATH%202003%20WU.
Full textIncludes bibliographical references (leaves 76-77). Also available in electronic version. Access restricted to campus users.
Ma, Jianqiang. "Photodissociation Dynamics and Collision Energy Transfer of Highly Excited SO2." Diss., Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/213110.
Full textPh.D.
As one of the simplest tri-atomic molecules, SO2 is extremely important in various fields in chemistry. SO2 is released by volcanoes and various industrial processes including combustion of sulfur containing fuel, and is well known to be the key chemical that causes the acid rain on earth. Therefore, SO2 has been studied intensively in both atmospheric chemistry as well as combustion chemistry. SO2 has also been discovered in extraterrestrial environment. For example, it is reported to be the most abundant gas observed in the atmosphere of Jupiter's moon, Io[1]. It has therefore generated great interests in the planetary chemistry as well. Even though understanding the structure, spectroscopy and reaction dynamics of SO2 has been of great and fundamental interests for more than 50 years, there are yet some very interesting topics, particularly those related to highly excited SO2, that require further investigations. In this thesis, we combine time-resolved Fourier transform infrared emission spectroscopy with theoretical modeling to study selected interesting problems relevant to highly excited SO2. First, the photodissociation of SO2 molecule by 193 nm photons is investigated. The role of different predissociation channels of electronically excited SO2 is carefully defined. Secondly, the excitation of SO2 by hot H atoms, a topic important in combustion and atmospheric chemistry, is examined. The energy transfer mechanism is identified and discussed. This newly discovered energy transfer mechanism involves the formation of the reactive intermediate species, which will greatly enhance the energy transfer efficiency on top of the classical impulsive type of collision mechanisms. In addition, the collision quenching of highly vibrationally excited SO2 with about 32,000 cm-1 energy is studied. It is found that the long range interactions contribute significantly to vibration to vibration (V-V) energy transfer. The contributions from both long range and impulsive mechanisms are discussed in detail. The studies presented in this thesis have provided important insight on the collision energy transfer and reaction dynamics of highly excited SO2 that would be useful in assessing the behavior of this important molecule in atmospheric, planetary, and combustive environments.
Temple University--Theses
Exner, Karsten. "Bewitterung von Kalk- und Zementmörteln mit CO2, SO2 und NO x." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960940944.
Full textCampion, Robin. "Imaging measurements of volcanic SO2 using space and ground based sensors." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209886.
Full textthird most abundant constituent after water vapor and carbon dioxide. SO2 flux measurements
are used to characterized and monitor volcanic degassing. This thesis presents advanced
methods for measuring the SO2 emitted in the troposphere by passive degassing volcanoes.
These methods are based on the absorption of infrared (IR) and ultraviolet (UV) light by SO2
molecules. They make use of the data acquired by satellite borne sensors (ASTER, OMI and
MODIS), and collected in the field using a UV camera equipped with filters
ASTER is a multispectral sensor observing the Earth in the thermal IR with a 90 m
ground resolution. The developed retrieval algorithm works with band ratios
(B10+B12)/2B11 and B14/B11, to avoid spectral interference from other variables than SO2.
With this algorithm, the impact of interferers such as atmospheric water vapor, sulfate
aerosols and ground emissivity is minimal, as demonstrated by radiative transfer simulations
by applying of the algorithm to real ASTER images and by comparing the results with ground
based data. ASTER is a kind of unifying thread for this thesis because its high ground
resolution fills the gap existing between highly localized ground based SO2 measurements and
the global coverage of other satellites with coarser pixels such as OMI and MODIS.
OMI is an imaging spectrometer operating in the UV, with a daily global coverage, a
high sensitivity to SO2 and a ground resolution of 13x24km. The OMI-ASTER comparison
shows that the SO2 columns measured on OMI pixels are two orders of magnitude smaller
than those of ASTER, because of the huge difference in the pixel size of the two satellites.
The flux measurements however are generally in good agreement. The analysis of a large
number of images shows that ASTER is better for cloud free scenes while OMI has an
optimal signal to noise ratio when the plume is lying above a low cloud cover. A practical
detection limit for SO2 flux measurements in tropospheric plumes has also been established:
5kg/s.
The comparison between ASTER measurements of SO2 column amounts with those of
MODIS (a multispectral IR imager with 1km ground resolution) shed light on systematic
errors in MODIS measurements. These errors were quantified and their origins were separated
and identified. This work demonstrates the limitations of MODIS for SO2 measurements.
A UV camera equipped with filters has also been developed to achieve 2D SO2 from the
ground at a high spatial and temporal resolution. The potential provided by this new type of
instruments has been demonstrated during a field campaign on Turrialba Volcano (Costa
Rica). The integration of measurements obtained using the camera, ASTER and OMI revealed
a high and sustained SO2 flux, which can be explained only by the degassing of a recently
intruded magma body. The slow decrease of SO2 flux since January 2010 suggests a
progressive exhaustion of the volatile content of the magma.
Finally, we applied the band ratio algorithm to a series of ASTER images of the recent
eruption of Eyjafjallajökull in April-May 2010. The SO2 measurements provide interesting
insights into the complex eruptive dynamics and into the control of hydromagmatic
interactions on eruptive gas release into the atmosphere. /
Le dioxyde de soufre (SO2) est un gaz typique du dégazage magmatique de haute
température, dont il est le troisième composant le plus abondant derrière H2O et CO2. Le flux
de SO2 est un excellent paramètre pour caractériser le dégazage volcanique et surveiller son
évolution dans le temps. Cette thèse présente de nouvelles méthodes de mesures des flux de
SO2 émis par l’activité volcanique. Ces méthodes se basent sur l’absorption de la molécule de
SO2 dans l’infrarouge (IR) et l’ultraviolet (UV). Elles utilisent les données prises par des
senseurs embarqués sur des satellites (ASTER, OMI et MODIS) ou opérés depuis le sol
(caméra UV munie de filtres).
Le senseur ASTER opère dans l’IR thermique avec une résolution spatiale de 90 m par
pixel. L’algorithme de mesure développé pour ce satellite n’est sensible qu’à la concentration
en SO2 et pratiquement pas aux paramètres interférents qui posaient problèmes aux méthodes
existantes :la vapeur d’eau atmosphérique, les aérosols de sulfate dans le panache et
l’émissivité de la surface sous-jacente. ASTER est un peu le fil conducteur de cette thèse, car
sa haute résolution spatiale lui permet de faire le lien entre des mesures au sol et les mesures
faites par d’autres satellites comme OMI et MODIS.
Le satellite OMI est un spectromètre imageant qui opère dans l’UV, avec une
couverture globale journalière, une haute sensitivité au SO2 et une résolution spatiale de
13x24km. La comparaison OMI-ASTER montre que les colonnes mesurées sur les pixels
d’OMI sont de deux ordres de grandeur inférieurs à celles d’ASTER, à cause de la différence
de résolution spatiale entre les deux satellites. Les mesures de flux, par contre, montrent une
très bonne concordance. L’analyse d’un grand nombre d’images a permis d’établir qu’ASTER
est meilleur pour des scènes sans nuages tandis qu’OMI est meilleur quand une couverture
nuageuse présente sous le panache augmente son rapport signal sur bruit. Une limite de
détection pratique a aussi été établie pour les flux de SO2 dans les panaches volcaniques dans
la basse troposphère :5kg/s.
La comparaison des mesures d’ASTER avec celle de MODIS a permis de démontrer les
limites de MODIS pour la mesure du SO2. Des erreurs systématiques sur les mesures de
MODIS on été mises en évidence et quantifiées. Ces erreurs sont dues aux interférents
spectraux que sont la vapeur d’eau atmosphérique et les aérosols sulfatés. L’émissivité est
aussi un important facteur d’erreur pour MODIS.
Une caméra UV équipée d’un système de filtres a également été développée pour
mesurer le SO2 en 2D, à haute résolution spatiale et temporelle. Le potentiel offert par ce
nouveau type d’instrument a été démontré lors d’une campagne de mesures sur le volcan
Turrialba (Costa Rica). La combinaison de mesures de SO2 réalisée avec la caméra, ASTER
et OMI a permis de mettre en évidence des flux très élevés (30-50kg/s) qui ne peuvent
s’expliquer que par une intrusion récente de magma juvénile en cours de dégazage.
Enfin, les mesures de SO2 ont réalisées à partir des images ASTER pendant l’éruption
du volcan Eyjafjallajökull en avril-mai 2010. Ces mesures fournissent des informations
intéressantes sur les dynamismes éruptifs qui se sont succédé et sur le contrôle des émissions
de SO2 dans l’atmosphère par les interactions magma-eau.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Lowe, Miranda Jeanne. "Sources of ambient Sulfur Dioxide (SO2) in the metro Atlanta area." Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-04082007-231954/.
Full textDr. James Mulholland, Committee Chair ; Dr. Armistead Russell, Committee Member ; Dr. Michael Bergin, Committee Member.
Schoeman, Johannes Gerhardus. "H2SO4 stability of PBI–blend membranes for SO2 electrolysis Schoeman / H." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7567.
Full textThesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.
Rabie, Samuel Liversage. "SO2 and O2 separation by using ionic liquid absorption / S.L. Rabie." Thesis, North-West University, 2012. http://hdl.handle.net/10394/9100.
Full textThesis (MIng (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013
Hlabano-Moyo, Bongibethu Msekeli. "Separation of SO2/O2 using membrane technology / Bongibethu Msekeli Hlabano-Moyo." Thesis, North-West University, 2013. http://hdl.handle.net/10394/9447.
Full textThesis (MIng (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013