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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.
41

Simulation of heat conduction and soot combustion in diesel particulate filter

Nakamura, Masamichi, Yamamoto, Kazuhiro January 2012 (has links)
No description available.
42

Efeitos biológicos e avaliação dose-resposta das partículas de exaustão do diesel sobre o desenvolvimento embrionário inicial de camundongos / Biological effects and dose-response assessment of diesel exhaust particles on in vitro early embryo development in mice

Daniela Aparecida Nicolosi Foltran Januário 12 March 2010 (has links)
Experimentos anteriores realizados em nosso laboratório indicam que o sucesso gestacional é afetado pela poluição atmosférica. O presente estudo teve como objetivo avaliar os efeitos biológicos associados a uma curva dose resposta das partículas de exaustão do diesel (PED) sobre o desenvolvimento embrionário inicial e o potencial de implantação, utilizando-se como modelo a fertilização in vitro e o cultivo embrionário de camundongos. No Experimento 1, encontrou-se um efeito negativo dose-dependente sobre o desenvolvimento embrionário inicial, o processo de eclosão, a alocação das células e a morfologia da massa celular interna (MCI) dos blastocistos. A análise post-hoc revelou que o desenvolvimento precoce do embrião não foi afetado pelas concentrações de 0,2 µg/cm2 ou 2 µg/cm2, mas foi significativamente afetado pela concentração de 20 µg/cm2 de PED. O processo de eclosão foi prejudicado pelas concentrações de 2 µg/cm2 e 20 µg/cm2. A alocação das células da MCI e a relação entre as células da MCI e do trofectoderma foram significativamente afetadas por todas as concentrações. Adicionalmente, observou-se um efeito negativo sobre a morfologia da MCI para as concentrações de 2 µg/cm2 e 20 µg/cm2. O Experimento 2, apesar de não mostrar efeito significativo sobre o potencial de implantação, evidenciado pela capacidade de adesão dos blastocistos e crescimento trofoblástico, revelou que a morfologia da MCI no dia 8 de cultivo, as taxas de viabilidade e de apoptose celular e a expressão de Oct4 e Cdx2 foram significativamente afetadas. O teste HSD-Tukey demonstrou que a presença de PED (0,2 µg/cm2 e 2 µg/cm2) durante o desenvolvimento embrionário aumentou significativamente a taxa de células em apoptose dos embriões tanto no dia 5 quanto no dia 8 de cultivo e, embora a proporção de células viáveis no dia 8 tenha sido prejudicada por ambas as concentrações, apenas a exposição a 2 µg/cm2 de PED diminuiu a viabilidade celular no dia 5. Por outro lado, tanto a concentração de 0,2 µg/cm2 como a de 2 µg/cm2 tiveram um efeito negativo significativo sobre a qualidade da MCI no dia 8 e a taxa de expressão de Oct4 nos blastocistos e aumentaram a porcentagem de células desses blastocistos expressando Cdx2, adicionalmente, a razão Oct4/Cdx2 dos embriões expostos a 0,2 µg/cm2 e 2 µg/cm2 foi significativamente menor. Frente a esses resultados, presumi-se que as PED poderiam estar envolvidas nos mecanismos que levariam à diminuição do sucesso reprodutivo observado em camundongos expostos à poluição atmosférica ambiental / Previous experiments conducted in our laboratory demonstrate that successful pregnancy is affected by air pollution. The aim of this study was to evaluate the biological effects associated with a dose-response curve of the diesel exhaust particles (DEP) on early embryonic development and implantation potential, using mice in vitro fertilization and culture embryo as model. In Experiment 1, we found a negative dose-dependent effect on the embryonic development, hatching process, cell allocation and morphology of inner cell mass (ICM) of blastocysts. A post-hoc analysis revealed that the early development of the embryo was not affected by concentrations of 0.2 g/cm2 or 2g/cm2, but was significantly affected by the concentration of 20 g/cm2 of DEP. The hatching process was impaired by concentrations of 2 g/cm2 and 20 g/cm2. Cell allocation of ICM and the ratio between cells of ICM and trophectoderm were significantly affected by all concentrations. Addicionaly, we observed a negative effect on ICM morphology was observed for the 2 µg/cm2 and the 20 µg/cm2 concentrations. Experiment 2, despite showing no significant effect on implantation potential, as evidenced by the adhesion ability and trophoblast outgrowth, revealed that ICM morphology on day 8 of culture, rates of cell viability and apoptosis, and expression of Oct4 and Cdx2 were significantly affected. The Tukey HSD test showed that presence of DEP (0.2 g/cm2 and 2 g/cm2) during embryonic development increased significantly the rate of apoptotic cells in embryos as on day 5 as on day 8 of culture, although the proportion of viable cells on day 8 was impaired by both concentrations, only exposure to 2 g/cm2 PED decreased cell viability on day 5. On the other hand, both the concentration of 0.2 g/cm2 such as 2 g/cm2 had a significant negative effect on the quality of ICM on the day 8 and the rate of expression of Oct4 on blastocysts, and increased the percentage of cells from these embryos expressing Cdx2, also, Oct4/Cdx2 ratio were significantly lower in the blastocysts derived from embryos exposed to 0.2 g/cm2 and 2 g/cm2¬ concentrations. Given these results, the suggestion is that DEP could be involved in the mechanisms that lead to decreased reproductive success observed in mice exposed to environmental pollution
43

Pro-atherothrombotic effects of acute diesel exhaust exposure: vascular and hemostatic insights

Wauters, Aurélien 21 February 2018 (has links)
Résumé Responsable de près de 7 millions de décès prématurés par an à travers le monde, la pollution atmosphérique représente un problème sanitaire mondial majeur. L’exposition humaine à la pollution particulaire dont les émissions de diesel représentent la principale source, est responsable d’une élévation de la mortalité et de l’incidence d’événements cardiovasculaires. Les mécanismes physiopathologiques sous-tendant cette toxicité aigue restent à ce jour largement méconnus. A l’aide d’une méthodologie d’exposition standardisée aux émissions de diesel, nous avons exploré les effets vasculaires périphériques et pulmonaires ainsi que les effets hémostatiques et plaquettaires secondaires à l’inhalation particulaire chez des sujets sains. L’étude dynamique de la microcirculation périphérique par Laser Doppler Imager nous a permis de démontrer une altération de la vasomotricité endothélium-dépendante induite par l’exposition aux émissions de diesel. La dysfonction observée est associée à une diminution de la biodisponibilité locale du NO ainsi qu’à une production radicalaire accrue au sein de la cellule endothéliale. Au cours d’une épreuve dynamique d’élévation du débit cardiaque par infusion de dobutamine, l’exposition aiguë aux émissions de diesel entraîne une élévation de la résistance vasculaire pulmonaire et une diminution de la distensibilité vasculaire pulmonaire mesurées par échocardiographie. Enfin, l’expression de surface des marqueurs d’activation plaquettaire CD62p (P-selectine) et CD63 est augmentée après exposition aux émissions de diesel, en corrélation avec la quantité de particules inhalées et constitue ainsi un état d’activation plaquettaire accru sans toutefois de modification de l’agrégation plaquettaire. A travers ces effets vasculaires systémiques et pulmonaires ainsi que ces effets hémostatiques, l’exposition aux émissions de diesel entraîne une toxicité cardiovasculaire aiguë, agissant en synergie, capable de déclencher la survenue d’événements cardiovasculaires.Abstract Responsible for up to 7 million deaths/year, air pollution is a major worldwide health burden. Particulate human exposure mainly originates from diesel exhaust and is associated with an increased cardiovascular mortality and an increased onset of cardiovascular events. Physiopathologic mechanisms underlying this acute toxicity remain largely unknown. We used a standardized diesel exhaust exposure protocol to explore not only the peripheral and pulmonary vascular effects, but also the hemostatic and platelet modifications in healthy subjects after particulate inhalation. Diesel exhaust exposure impairs the endothelium-dependant vasodilation during a dynamic evaluation of the peripheral microcirculation assessed by Laser Doppler Imager, whilst the endothelial independent vasodilatation remains unaffected. Vascular dysfunction is associated to a decreased local NO bioavailability and an increased endothelial reactive oxygen species production. During a dynamic cardiac stress test using continuous dobutamine infusion, acute diesel exhaust exposure induces an increased pulmonary vascular resistance associated to a decreased pulmonary vascular distensibility, both evaluated by echocardiography. Finally, platelet activation is modified after diesel exhaust exposure with an increased CD62p (P-selectin) and CD63 platelet surface expression, correlated with the total amount of inhaled particles. We observed a state of platelet activation without change in platelet aggregation. Through these multiples effects, combining systemic and pulmonary vascular impairment with platelet prothrombotic modifications, diesel exhaust exposure induces an acute cardiovascular toxicity, which can synergistically trigger acute events. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished
44

Dielectric Barrier Discharge Initiated NOx Abatement In Diesel Engine Exhaust : Towards Achieving Higher Removal Efficiency

Mohapatro, Sankarsan 07 1900 (has links) (PDF)
In the last few decades India has advanced socioeconomically due to the rapid growth of industries and automobile sector. This in turn increases the use of fossil fuel and diesel. The atmosphere gets polluted due to the harmful substances, which comes from the burning of fuel. These pollutants can be in the form of gaseous, liquid or solid particulate. Diesel engines, the major source of power in industries and automobiles, play a significant part in causing air pollution. The major pollutants in diesel exhaust are oxides of nitrogen (NOX), sulphur dioxide (SO2), carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), volatile organic compounds (VOC), aldehydes and alcohols. Due to the heavy consumption of diesel as a fuel there is an urgent need to control diesel exhaust. Diesel exhaust is a complex mixture of several gases and fine particles (commonly known as soot) that contains more than 40 toxic air contaminants. Amongst the gaseous pollutants in diesel exhaust, the major concern and a challenging task is to control oxides of nitrogen, commonly referred to as NOX as it is the major contributor for acid rain, photochemical smog etc. Successful control of emissions from diesel engines is yet to be achieved. The conventional techniques which are available to control emission now are either difficult to operate or does not satisfy the stringent emission standards. This has made the researchers throughout the world to find an alternative and effective non-conventional after treatment technique to reduce diesel engine emission. The failure of conventional techniques lead to the development of non-conventional techniques such as high voltage electric discharge based plasma which has already been proved to be economical and highly efficient in industrial electrostatic precipitators. Electric discharge plasma or non-thermal plasma produce energetic electrons which react with background molecules in flue gas leading to active species such as radicals. These radicals being chemically active selectively react with the harmful pollutants facilitating their removal/reduction. The present thesis work is an attempt to provide a technical solution to achieve higher removal efficiencies of oxides of nitrogen in the backdrop of shortcomings that exist in conventional technologies to do so. The current thesis describes the research in four stages: (i) studies on NOX removal from diesel exhaust by cross-flow DBD reactor, where design and fabrication of cross-flow DBD reactor, exhaust treatment using cross-flow DBD reactor and exhaust treatment with cascaded plasma-adsorbent technique is described (ii) studies on NOX removal from diesel exhaust by compact discharge plasma sources, where design and fabrication of high frequency high voltage AC (HVAC) using old television flyback transformer, Design and fabrication of high voltage pulse (HVPulse) using automobile ignition coil, exhaust treatment with both HVPulse and HVAC and exhaust treatment with cascaded plasma-adsorbent technique is described (iii) studies on NOX removal from diesel exhaust using solar powered discharge plasma source is described (iv) studies on the NOX removal from diesel exhaust using red mud, where exhaust treatment with red mud and Exhaust treatment cascaded plasma-red mud is covered. The results have been discussed in light of enhancing the NOX removal efficiency for stationary and automobile engine exhausts.
45

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS

SZYMKOWICZ, PATRICK 03 November 2017 (has links)
Diesel fuel is composed of a complex mixture of hundreds of hydrocarbons that vary globally depending on crude oil sources, refining processes, legislative requirements and other factors. In order to simplify the study of this fuel, researchers create surrogate fuels with a much simpler composition, in an attempt to mimic and control the physical and chemical properties of Diesel fuel. The first surrogates were single-component fuels such as n-heptane and n-dodecane. Recent advancements have provided researchers the ability to develop multi-component surrogate fuels and apply them to both analytical and experimental studies. The systematic application of precisely controlled surrogate fuels promises to further enhance our understanding of Diesel combustion, efficiency, emissions and particulates and provide tools for investigating new and alternative engine combustion systems. This thesis employed analytical and experimental methods to develop, validate and study a library of multi-component surrogate Diesel fuels. The first step was to design a surrogate fuel to precisely match the physical and chemical properties of a full-range petroleum Diesel fuel with 50 cetane number and a typical threshold soot index value of 31. The next step was to create a Surrogate Fuel Library with 18 fuels that independently varied two key fuel properties: cetane number and threshold soot index. Within the fuel library cetane number ranged from 35 to 60 at three threshold soot index levels of 17, 31 and 48 (low, mid-range and high). Extensive ASTM fuel property tests showed that good agreement with important physical and chemical properties of petroleum Diesel fuel such as density, viscosity, heating value and distillation curve. An experimental investigation was conducted to evaluate the combustion, emissions, soot and exhaust particles from the petroleum Diesel fuel and the matching surrogate fuel. A fully-instrumented single-cylinder Diesel engine was operated with combustion strategies including Premixed Charge Compression Ignition (PCCI), Low-Temperature Combustion (LTC) and Conventional Diesel Combustion (CDC). For combustion, the ignition delay, low-temperature (first stage) and high temperature (second stage) heat-release matched very well. Gaseous emissions, soot and exhaust particles maintained good agreement as exhaust gas recirculation and combustion phasing were varied. This thesis demonstrated that fully representative Diesel surrogate fuels could be tailored with the proper blending of the following hydrocarbon components: n-hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, decahydronaphthalene and 1-methylnaphthalene. It was also established that the volumetric blending fractions of these four components could be varied to independently control the fuel cetane number and threshold soot index while retaining the combustion, physical and chemical properties of full-range petroleum Diesel fuel. The Surrogate Fuel Library provided by this thesis supplies Diesel engine researchers and designers the ability to analytically and experimentally vary fuel cetane number and threshold soot index. This new capability to independently vary two key fuel properties provides a means to further enhance the understanding of Diesel combustion and design future combustion systems that improve efficiency and emissions. / El combustible diésel está compuesto por cientos de hidrocarburos cuya presencia y proporción varía dependiendo del origen del crudo, del proceso de refinado, de los requerimientos legislativos, y de muchos otros factores. Para evitar las dificultades que produce esta variabilidad y complejidad en su composición, en los estudios sistemáticos, los investigadores suelen trabajar con combustibles de sustitución, mucho más sencillos, pero que reproducen las propiedades químicas y físicas del gasóleo. Los primeros combustibles de sustitución estuvieron formados por un solo componente, como el n-heptano y el n-dodecano. Recientemente se han desarrollado combustibles de sustitución multi-componentes, que se aplican tanto a estudios experimentales como de modelado. La aplicación sistemática de combustibles de sustitución controlados con precisión es una vía prometedora para mejorar la comprensión de la combustión Diesel, su eficiencia, y sus emisiones y proporciona herramientas para la investigación de sistemas de combustión nuevos y alternativos. En esta tesis se han empleado métodos experimentales y de cálculo para desarrollar, estudiar y validar una librería de combustibles de sustitución multi-componentes. El primer combustible de sustitución se diseñó para reproducir con precisión las propiedades físicas y químicas de un gasóleo con número de cetano 50 y un índice de hollín umbral (TSI) de 31.El siguiente paso fue crear una biblioteca de combustibles de sustitución con 18 combustibles que pueden modificar independientemente dos propiedades clave del combustible: índice de cetano y TSI. En la biblioteca de combustibles el número de cetano osciló entre 35 y 60 con tres niveles de TSI iguales a 17, 31 y 48 (bajo, medio y alto rango). Los ensayos según la normativa ASTM demostraron una buena coincidencia con las propiedades del gasóleo como densidad, viscosidad, poder calorífico y curvas de destilación. Para comprobar la validez de la librería, se realizó un estudio experimental comparativo sobre el proceso de combustión, las emisiones gaseosas, hollín y partículas de un gasóleo y de su combustible de sustitución ajustado. El estudio se realizó con un motor monocilíndrico Diesel completamente instrumentado y operando con estrategias de combustión en premezcla parcial (PPCI) y de baja temperatura (LTC), además de la combustión Diesel convencional (CDC). Los parámetros de la combustión como el retraso al encendido y la liberación de calor tanto de baja como de alta temperatura se aproximaron muy bien. Las emisiones de gases, hollín y partículas también fueron similares al variar el nivel de EGR y la fase de la combustión. La tesis demuestra que se pueden encontrar combustibles de sustitución perfectamente representativos de un gasóleo corriente, en base a mezclas apropiadas de n-hexadecano, 2,2,4,4,6,8,8-heptamethylnonano, decahidronaftaleno y 1-metilnaftaleno. Asimismo, se concluye que variando la proporción de estos cuatro componentes se puede controlar independientemente el número de cetano y el índice de hollín umbral, a la vez que se mantienen las propiedades físico-químicas y de combustión del gasóleo. La librería de combustibles de sustitución definida en esta tesis es una herramienta a disposición de los investigadores para profundizar en el conocimiento de la combustión diésel y avanzar en el diseño de sistemas futuros de combustión con mejor rendimiento y menores emisiones. / El combustible Diesel està compost per centenars d'hidrocarburs, la presència i proporció dels quals varia depenent de l'origen del cru, del procés de refinat, dels requeriments legislatius, i de molts altres factors. Per a evitar les dificultats que produeix aquesta variabilitat i complexitat en la seua composició, en els estudis sistemàtics, els investigadors solen treballar amb combustibles de substitució, molt més senzills, però que reprodueixen les propietats químiques i físiques del gasoil. Els primers combustibles de substitució van estar formats per un sol component, com el n-heptà i el n-dodecà. Recentment s'han desenvolupat combustibles de substitució multi-components, que s'apliquen tant a estudis experimentals com de modelatge. L'aplicació sistemàtica de combustibles de substitució controlats amb precisió és una via prometedora per a millorar la comprensió de la combustió Dièsel, la seua eficiència, i les seues emissions i proporciona eines per a la recerca de sistemes de combustió nous i alternatius. En aquesta tesi s'han emprat mètodes experimentals i de càlcul per a desenvolupar, estudiar i validar una llibreria de combustibles de substitució multi-components. El primer combustible de substitució es va dissenyar per a reproduir amb precisió les propietats físiques i químiques d'un gasoil amb índex de cetà 50 i un índex de sutge límit (TSI) de 31. El següent pas va ser crear una biblioteca de combustibles de substitució amb 18 combustibles que poden modificar independentment dues propietats clau del combustible: índex de cetà i TSI. En la biblioteca de combustibles l'índex de cetá va oscil·lar entre 35 i 60 amb tres nivells de TSI iguals a 17, 31 i 48 (baix, mitjà i alt rang). Els assajos segons la normativa ASTM van demostrar una bona coincidència amb les propietats del gasoil com a densitat, viscositat, poder calorífic i corbes de destil·lació. Per a comprovar la validesa de la llibreria, es va realitzar un estudi experimental comparatiu sobre el procés de combustió, les emissions gasoses, sutge i partícules d'un gasoil i del seu combustible de substitució ajustat. L'estudi es va realitzar amb un motor monocilíndric Dièsel completament instrumentat i operant amb estratègies de combustió en premescla parcial (PPCI) i de baixa temperatura (LTC), a més de la combustió Dièsel convencional (CDC). Els paràmetres de la combustió com el retard a l'encès i l'alliberament de calor tant de baixa com d'alta temperatura es van aproximar molt bé. Les emissions de gasos, sutge i partícules també van ser similars en variar el nivell d'EGR i la fase de la combustió. La tesi demostra que es poden trobar combustibles de substitució perfectament representatius d'un gasoil corrent, sobre la base de mescles apropiades de n-hexadecà, 2,2,4,4,6,8,8-heptamethylnonà, decahidronaftalé i 1-metilnaftaleno. Així mateix, es conclou que variant la proporció d'aquests quatre components es pot controlar independentment l'índex de cetà i l'índex de sutge límit, alhora que es mantenen les propietats físic-químiques i de combustió del gasoil. La llibreria de combustibles de substitució definida en aquesta tesi és una eina a la disposició dels investigadors per a aprofundir en el coneixement de la combustió Diesel i avançar en el disseny de sistemes futurs de combustió amb millor rendiment i menors emissions. / Szymkowicz, P. (2017). ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90406 / TESIS
46

Struktur und Aktivität von Al2O3-geträgerten Eisenoxid-Katalysatoren zur Reinigung von Dieselabgas

Roppertz, Andreas 07 September 2016 (has links)
In der vorliegenden Arbeit werden Al2O3-geträgerte Eisenoxid-Katalysatoren auf ihre Eignung in der Nachbehandlung von Dieselabgasen getestet. Hierbei werden die Oxidationsreaktionen von Kohlenmonoxid, Propen, Stickstoffmonoxid sowie Ammoniak getestet. Weiterhin wird die Katalysatoraktivität bei der Stickoxidminderung nach dem SCR-Verfahren untersucht. Basierend auf einer detaillierten Charakterisierung wird eine Struktur-Aktivitäts-Korrelation entwickelt, auf deren Basis ein Verständnis für die Art der aktiven Zentren solcher Katalysatoren generiert wird. Zudem wird ein Modell entwickelt, mit Hilfe dessen die spezifische Aktivität der verschiedenen Typen an aktiven Zentren bewertet werden kann. Darüber hinaus wird in dieser Arbeit auf die Stickoxidminderung nach dem SCR-Verfahren fokussiert, was die Untersuchungen des Reaktionsmechanismus sowie die Struktur-Aktivitäts-Korrelation an hydrothermal gealterten Katalysatoren beinhaltet.:Inhalt 1. Einleitung 2. Aufgabenstellung 3. Grundlagen 3.1 Schadstoffbildung bei der Verbrennung fossiler Energieträger 3.2 Verfahren zur Schadstoffminderung bei Kraftfahrzeugen 3.3 Aktueller Stand der Entwicklung edelmetallfreier Katalysatoren für die dieselmotorische Abgasnachbehandlung 4. Verwendete Analysemethoden und Aufbau der Laborapparaturen 4.1 Untersuchungen zur Struktur der Katalysatoren 4.1.1 Stickstoff-Physisorption 4.1.2 Temperaturprogrammierte Experimente 4.1.3 Röntgendiffraktometrie 4.1.4 DRUV/VIS-Spektroskopie 4.1.5 Diffuse Reflexions-Infrarot-Fourier-Transformations-Spektroskopie 4.1.6 Transmissionselektronenmikroskopie 4.1.7 Mößbauer-Spektroskopie 4.1.8 Raman-Spektroskopie 4.2 Untersuchungen zur Analyse von Gasen 4.2.1 Fourier-Transform-Infrarotspektroskopie (FTIR) 4.2.2 Massenspektrometrie 4.3 Aufbau der Laborapparaturen 4.3.1 Laborapparatur für Aktivitätsmessungen sowie für temperaturprogrammierte Experimente 4.3.2 Laborapparatur zur Durchführung von DRIFTS-Experimenten 5 Experimentelle Ergebnisse 5.1 Katalysatorpräparation 5.2 Charakterisierung der frischen Katalysatoren 5.3 Charakterisierung der hydrothermal gealterten Katalysatoren 5.4 Aktivitätsmessungen 5.4.1 Oxidation von Kohlenmonoxid 5.4.2 Oxidation von Propen 5.4.3 Oxidation von Stickstoffmonoxid 5.4.4 Oxidation von Ammoniak 5.5 Untersuchungen zur Standard-SCR-Reaktion 5.5.1 Aktivitätsuntersuchung an frischen Katalysatoren 5.5.2 Aktivitätsuntersuchung an hydrothermal gealterten Katalysatoren 5.5.3 Untersuchungen zum Mechanismus der SCR-Reaktion 6. Diskussion der Ergebnisse 6.1 Struktur-Aktivitäts-Beziehung der FexO/Al2O3-Katalysatoren 6.1.1 Struktur der Eisenoxidspezies 6.1.2 Quantifizierung der Eisenoxidspezies 6.1.3 Modell zur Berechnung der spezifischen Aktivität der Katalysatoren 6.1.4 Sensitivitätsanalyse des entwickelten Modells 6.1.5 Anwendung des Modells bei der Oxidation von CO, C3H6, NO und NH3 6.1.6 Struktur-Aktivitäts-Beziehung der FeOx/Al2O3-Katalysatoren bei der Oxidation von CO, C3H6, NO und NH3 6.2 Evaluation der SCR-Aktivität der FeOx/Al2O3-Katalysatoren 6.2.1 Untersuchungen an frischen Katalysatoren 6.2.2 Einfluss der hydrothermalen Alterung auf die Katalysatorstruktur und -aktivität bei der Standard-SCR-Reaktion 6.3 Mechanismus der Standard-SCR-Reaktion an FeOx/Al2O3-Katalysatoren 7. Ausblick 8. Literaturverzeichnis 9. Anhang
47

Exponering av luftföroreningar : -vid arbete i hamnmagasin / Occupational exposure to air pollution : -at port warehouse

Nordgren, Susanne January 2015 (has links)
Syftet med examensarbetet var att översiktligt undersöka vilka hälsofarliga luftföroreningarsom medarbetarna vid hamnmagasinen eventuellt exponeras föroch huruvida något hygieniskt gränsvärde riskerade att överskridas samt att seom de skyddsåtgärder som vidtagits kan förbättras. Resultatet från studien visaratt det finns vissa exponeringsrisker för de som arbetar vid hamnen både frångods, dieselavgaser samt rester av gasbehandlingsmedel i containrar.Arbetsmomenten där truckföraren befinner sig inne i trucken bedöms somrelativt skyddat både från partiklar och gaser, men det finns andra arbetsuppgifterdär arbetaren inte är lika skyddad. Mätningarna av kvävedioxid visadeatt exponeringen av dieselavgaser för den medarbetare som öppnadecontainrarna inte översteg några hygieniska gränsvärden, under de dagar sommätningarna genomfördes, men var något högre än för truckföraren som satt ihytten. Huruvida exponeringen av damm från gods riskerar att utvecklas tillhälsoproblem är omöjligt att avgöra utan en grundlig riskbedömning, därdammätningar kan ge en fingervisning om hur riskfylld situationen är för desom eventuellt exponeras.Organisationen bör implementera säkrare rutiner och genomföra åtgärder sommotiverar medarbetarna att använda befintlig skyddsutrustning. Det gäller intebara för exponering av dieselavgaser och damm från lossning och lastning avgods utan även vid öppnandet av containrar där rester av gasbehandlingsmedelkan finnas kvar i containern och där några ämnen misstänkts varacancerframkallande.Slutsatser: Genomföra en grundlig riskbedömning och kartlägga möjliga hälsoriskerkring luftföroreningar. Upprätta skriftliga arbetsbeskrivningar där eventuella risker föreligger. Installera ventilation i magasinen som styrs av halten kvävedioxid för attsäkerställa att höga halter av dieselavgaser inte uppstår. Behov av motivationshöjande insatser kring säkerhetskultur ochanvändningen av skyddsutrustning. Implementera fungerande rutiner som följer lagstiftningen förhanteringen av damm och gaser som gäller för cancerframkallandeämnen. / The purpose of this thesis was to examine the risk of hazardous air pollutantsthat employees at the harbor may be exposed to and assess whether anyexposure limits might be exceeded, and to review if the security measures taken,can be improved. The results of the study show that there is some risk ofexposure for those working in the harbor from both the cargo, diesel exhaustand residues from fumigants in the containers. The operations when the truckdriver is inside the forklift is considered relatively protected from both particlesand gases, but there are other tasks where the worker is not as protected.Measurements of nitrogen dioxide showed that exposure to diesel exhaust forthe employee who opened the containers during the days that the measurementswere performed did not exceed some critical values, but was slightly higherthan for the driver who was sitting in the forklift. Whether the exposure to dust,from the cargo, constitutes a risk for health effects is impossible to determinewithout a thorough risk assessment, where measurements of dust can give anindication of how risky the situation is for the exposed workers.The organization should implement safer practices and implementing measuresthat motivates employees to use existing protective equipment. This applies notonly for exposure to diesel exhaust and dust from loading and unloading ofgoods, but also at the opening the doors on the containers in which residues offumigants, in which some are suspected to be carcinogenic, can remain in thecontainer.Conclusions: Conduct a thorough risk assessment and identify potential health riskswith air pollution. Establish written work instructions where potential hazards exist. Install ventilation in the warehouses, which is controlled by the levels ofnitrogen dioxide, to ensure that high levels of diesel exhaust does notoccur. Need to increase motivation for safety and the use of protectiveequipment. Implement procedures to comply with the legislation for the managementof dust and gases that applies to carcinogens substances.
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Avaliação das funções erétil e vascular de ratos com inflamação pulmonar decorrente da exposição ao material particulado ambiental liberado na exaustão do diesel. / Evaluation of erectile and vascular functions in rat with lung inflammation evoked by exposure to diesel exhaust particles.

Oliveira, Juliano Fernandes de 30 September 2010 (has links)
Este estudo se propôs a avaliar o potencial inflamatório das partículas eliminadas na exaustão do diesel (PED) e 1,2-naftoquinona (1,2-NQ) sobre outros compartimentos, como o músculo liso vascular (aorta torácica; RTA) e do corpo cavernoso isolados de ratos (RCC) e os mecanismos envolvidos via ensaios funcionais e bioquímicos. A injeção i.tr. das PED e 1,2-NQ em ratos Wistar causou inflamação e hiporreatividade das vias aéreas associados ao aumento significativo do relaxamento evocado pela ACh na RTA. No RCC desses mesmos animais, tanto o GTN quanto o estímulo elétrico (EFS) causou maior relaxamento. O conteúdo basal de TBARs na RTA e pulmão foi reduzido, embora outros testes indicadores de estresse oxidativo e / ou atividade antioxidante não mostraram diferenças entre os grupos. As taxas de expressão gênica / protéica da nNOS no RCC de ratos não diferiram do grupo controle, mas a expressão da eNOS e iNOS foi reduzida na RTA e RCC. Não foram quantificadas concentrações séricas do TNF<font face=\"Symbol\">&#945 ou IL-1<font face=\"Symbol\">b, sugerindo que os efeitos sistêmicos ocorrem independentemente destas citocinas. Conclui-se que o tratamento agudo de ratos com a mistura de poluentes induziu inflamação das vias aéreas (e hiporreatividade), capaz de afetar outros compartimentos, como a musculatura lisa vascular (RTA) e do RCC. / We tested the hypothesis that local inflammation in the airways evoked by intra-tracheal instillation of the environmental chemical 1,2-naphthoquinone (1,2-NQ) and diesel exhaust particles (DEP) is capable of targeting other systemic compartments, such as vessels (rat thoracic aorta; RTA) and corpus cavernosum (RCC), and possible involved mechanisms. After 3h, this treatment induced airways hyporresponsiveness to ACh and local inflammation. This effect was associated with decreased numbers of leukocyte in the blood and spleen and increased number of leukocytes in the bone marrow. Pollutant treatment also markedly increased ACh-induced relaxation in RTA and by both GTN- and electrical stimulation-induced relaxation in RCC. Exposure to pollutants did not affect FE-induced contraction in RTA. Neither serum levels of cytokines (TNF<font face=\"Symbol\">&#945 e IL-1<font face=\"Symbol\">b) nor basal concentration of total nitrate were different amongst groups. No evidence of increased catalase activity in RTA, RCC and lung was found. The treatment reduced the eNOS e iNOS gene expression in RTA e RCC, without significantly affecting the nNOS gene expression in RCC. Our results are consistent with the hypothesis that DEP-induced airways hiporresponsiveness and inflammation can account to produce systemic changes, such as structural and functional changes in the RTA and RCC by means of substances derived from endothelium or due to the ability of these pollutants to act to stimulate the production of scavenger of free radical.
49

Avaliação das funções erétil e vascular de ratos com inflamação pulmonar decorrente da exposição ao material particulado ambiental liberado na exaustão do diesel. / Evaluation of erectile and vascular functions in rat with lung inflammation evoked by exposure to diesel exhaust particles.

Juliano Fernandes de Oliveira 30 September 2010 (has links)
Este estudo se propôs a avaliar o potencial inflamatório das partículas eliminadas na exaustão do diesel (PED) e 1,2-naftoquinona (1,2-NQ) sobre outros compartimentos, como o músculo liso vascular (aorta torácica; RTA) e do corpo cavernoso isolados de ratos (RCC) e os mecanismos envolvidos via ensaios funcionais e bioquímicos. A injeção i.tr. das PED e 1,2-NQ em ratos Wistar causou inflamação e hiporreatividade das vias aéreas associados ao aumento significativo do relaxamento evocado pela ACh na RTA. No RCC desses mesmos animais, tanto o GTN quanto o estímulo elétrico (EFS) causou maior relaxamento. O conteúdo basal de TBARs na RTA e pulmão foi reduzido, embora outros testes indicadores de estresse oxidativo e / ou atividade antioxidante não mostraram diferenças entre os grupos. As taxas de expressão gênica / protéica da nNOS no RCC de ratos não diferiram do grupo controle, mas a expressão da eNOS e iNOS foi reduzida na RTA e RCC. Não foram quantificadas concentrações séricas do TNF<font face=\"Symbol\">&#945 ou IL-1<font face=\"Symbol\">b, sugerindo que os efeitos sistêmicos ocorrem independentemente destas citocinas. Conclui-se que o tratamento agudo de ratos com a mistura de poluentes induziu inflamação das vias aéreas (e hiporreatividade), capaz de afetar outros compartimentos, como a musculatura lisa vascular (RTA) e do RCC. / We tested the hypothesis that local inflammation in the airways evoked by intra-tracheal instillation of the environmental chemical 1,2-naphthoquinone (1,2-NQ) and diesel exhaust particles (DEP) is capable of targeting other systemic compartments, such as vessels (rat thoracic aorta; RTA) and corpus cavernosum (RCC), and possible involved mechanisms. After 3h, this treatment induced airways hyporresponsiveness to ACh and local inflammation. This effect was associated with decreased numbers of leukocyte in the blood and spleen and increased number of leukocytes in the bone marrow. Pollutant treatment also markedly increased ACh-induced relaxation in RTA and by both GTN- and electrical stimulation-induced relaxation in RCC. Exposure to pollutants did not affect FE-induced contraction in RTA. Neither serum levels of cytokines (TNF<font face=\"Symbol\">&#945 e IL-1<font face=\"Symbol\">b) nor basal concentration of total nitrate were different amongst groups. No evidence of increased catalase activity in RTA, RCC and lung was found. The treatment reduced the eNOS e iNOS gene expression in RTA e RCC, without significantly affecting the nNOS gene expression in RCC. Our results are consistent with the hypothesis that DEP-induced airways hiporresponsiveness and inflammation can account to produce systemic changes, such as structural and functional changes in the RTA and RCC by means of substances derived from endothelium or due to the ability of these pollutants to act to stimulate the production of scavenger of free radical.

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