A poluição atmosférica já é considerada um caso de saúde pública nos grandes centros urbanos. Freqüentemente as emissões veiculares são as principais causas dessa poluição, principalmente as provenientes dos motores diesel, os quais, além da produção de material particulado (MP), em cuja superfície são adsorvidas substâncias carcinogênicas e mutagênicas, produzem poluentes como os hidrocarbonetos policíclicos aromáticos (HPAs). Contudo não existe uma avaliação direta dos riscos dessas emissões nos seres vivos. Plantas bioindicadoras podem dar idéia desses riscos. Este trabalho teve como objetivo avaliar o potencial de risco mutagênico da exaustão proveniente de um motor diesel, utilizando o bioensaio Trad-SH (clone KU-20) como bioindicador da poluição do ar. Nos experimentos, a exaustão do motor diesel aspirado de 2.0 L de deslocamento volumétrico foi diluído com ar atmosférico de modo a atingir concentrações de uma atmosfera pesadamente poluída (aproximadamente 50, 100 e 150 ppm de CO). Obtidos estes níveis de diluição, as inflorescências foram expostas a esta mistura de poluentes por duas horas (doses agudas). A concentração de CO foi monitorada continuamente por meio de um analisador de gases Horiba Enda utilizando o princípio de absorção seletiva no infravermelho. Para se avaliar o efeito mutagênico foi feita uma comparação entre as inflorescências não expostas aos poluentes (grupo 1) e as inflorescências expostas (grupos 2, 3 e 4) com aproximadamente 50, 100 e 150 ppm de CO respectivamente. Os dados obtidos foram analisados estatisticamente observando-se que, a freqüência média das mutações no grupo 1 (controle), foi significativamente mais baixa do que aquela dos grupos 3 e 4, porém foi similar à do grupo 2. Por sua vez, não houve diferenças significativas nas freqüências de mutações entre os grupos 3 e 4. Os resultados indicam que a exaustão do motor a diesel teve um papel significativo no desenvolvimento de mutações, mas somente quando diluída para concentrações de CO acima de 100 ppm. / Air pollution caused by vehicle emission has been considered as a major public health concern in the urban centers. Emission from diesel engine powered vehicles, in particular, are highly toxic, since carcinogenic and mutagenic compounds can adsorb on the expelled particles leading to the formation of the so-called polycyclic aromatic hydrocarbons (PAH\'s). A detailed investigation on the risks of those compounds on the living beings using the methodology applied in the work has not been carried out so far. This work is aimed at evaluating the mutagenic potential of the emission from a diesel engine using the Tradescantia stamen hair assay (TSH), by monitoring the stamen hair mutation in the clone KU-20. Experimentally, the inflorescence of the KU-20 clones was kept for 2 h under a simulated urban heavily polluted atmosphere, obtained by mixing the emission from a diesel engine and atmospheric air. The CO concentration in the atmosphere was monitored using a Horiba-Enda gas analyzer. The mutagenic effects of the atmosphere were analyzed by comparing a group of non-exposed control inflorescence (group 1) to inflorescences kept under polluted atmospheres containing 50, 100 and 150 ppm of CO, assigned to as groups 2, 3 and 4. The experimental data were analyzed using statistical methods. The frequency of mutations observed in the inflorescences from group 2 was slightly higher than that observed in the group 1. In the groups 3 and 4, however, the frequency of mutations was significantly higher than that exhibited by the control group. The latter suggests that the emission from a diesel engine plays an important role in the development of plants mutation, specially for atmospheres containing more than 100 ppm of CO.

O presente trabalho buscou estudar experimentalmente os efeitos do deslocamento da posição final dos dutos de admissão de um cabeçote no número de swirl e as possíveis consequências nos parâmetros de desempenho do motor diesel (torque, emissão de poluentes e consumo de combustível). Foram construídos protótipos de cabeçotes divididos em quatro grupos de deslocamentos com diferentes direções e sentidos. O valor nominal desses deslocamentos foi de 1 mm. Em seguida os cabeçotes passaram por medição de geometria para verificação da posição real dos dutos de admissão; posteriormente os cabeçotes foram ensaiados em uma máquina de medição do número de swirl. A partir dos dados de posição dos dutos de admissão e do número de swirl de cada cabeçote, foi feita uma regressão linear múltipla para se obter uma equação que correlaciona o número de swirl com os deslocamentos em X e Y dos dois dutos de admissão. Na última parte do trabalho, os cabeçotes de cada grupo de deslocamento foram montados sucessivamente em um motor diesel instalado em dinamômetro para medição dos seus parâmetros de desempenho, a saber: curva de torque; consumo específico e emissão de poluentes. / This work aimed to study experimentally the effects of intake ports displacement of a cylinder head in its swirl number and the possible consequences in the diesel engine performance parameters (torque, emissions and fuel consumption). Cylinder head prototypes were divided into four groups with different displacement directions. The nominal value of these displacements was 1 mm. The cylinder heads were measured to check the real position of their intake ports; then the cylinder heads were tested in a machine to measure the swirl number. From the intake ports position data and swirl number of each cylinder head, a multiple linear regression was performed to obtain an equation that correlates the swirl number with intake ports displacement in X and Y directions. As last step of this work, the cylinder heads of each displacement group were mounted in a diesel engine installed on a dynamometer to measure its performance parameters: torque curve; specific fuel consumption and emissions.

Existem motivações de ordem ambiental e energética para que combustíveis renováveis sejam cada vez mais utilizados. O biodiesel é uma das alternativas renováveis à utilização de óleo diesel de origem fóssil, e sua utilização tem crescido no mundo. No Brasil, existe uma propensão muito positiva para o cultivo de oleaginosas, e o biodiesel aparece como proposta de solução ambiental, energética e social. A utilização de biodiesel no Brasil tem sido crescente desde 2004 e torna-se-á compulsória a partir de 2008. Nas lavouras não é diferente, e a utilização do biodiesel no maquinário agrícola já é realidade em diversas fazendas do país. A fim de se conhecer as consequências em termos de desempenho, devido a utilização de biodiesel em motores do ciclo diesel, estudos se fazem necessários. O presente trabalho teve por objetivo comparar desempenho, consumo específico e emissão de gases de um motor originalmente concebido para funcionar com óleo diesel de origem mineral, utilizando-se misturas de biodiesel de soja e de nabo forrageiro em proporções de até 20 % em seu volume. Os ensaios foram realizados no laboratório de motores da Delphi, em Piracicaba, SP, em dinamômetro de motor assíncrono, em célula de medição automatizada. Não foram observadas diferenças significativas no desempenho do motor ao funcionar com misturas de biodiesel comparativamente ao diesel padrão. O HC foi maior para misturas de biodiesel em toda a faixa de operação do motor. O NOx mostrou-se maior apenas na faixa inicial de operação. Para o CO não se pôde atribuir uma tendência de emissões de gases relacionada ao biodiesel. Para os gases não poluentes, o biodiesel produziu menor oxigênio que o diesel padrão e mesmo nível de CO2. O consumo específico de combustível mostrou-se sensível à adição de biodiesel, sendo maior proporcionalmente às taxas de biodiesel utilizadas. A taxa de biodiesel adicionada nem sempre resultou em tendência proporcional de alteração nos resultados. / There are environmental and energetic motivations that lead to a higher usage of renewable fuels. Biodiesel is one of the renewable alternatives to the fossil diesel fuel and its usage has been growing worldwide. In Brazil there are positive conditions for the oil energetic agriculture and biodiesel emerges as a proposal for environemental, energetic and social solution. Utilization of biodiesel has been increasing since 2004 and will become obligatory starting 2008. Agricultural utilization of biodiesel on machines is already a reality in several farms in Brazil. In order to better understand the consequences in terms of engine performance due to biodiesel utilization in diesel engines, research is necessary. This work had the objective of comparing performance, specific fuel consumption and gas emissions of an engine originally designed to burn fossil diesel, using soy and forage turnip biodiesel / diesel blends in proportions up to 20 % in volume. Tests were performed at Delphi engine laboratories in Piracicaba, SP, in assincronous dynamometers, in a computer controlled test cell. No significative performance differences were found when running with biodiesel blends if compared to standard diesel. HC was higher with biodiesel blends for all engine operation range. NOx was higher only at initial engine operation range. It was not possible to attribute a tendence to CO emission related to biodiesel usage. For non-pollutant gases, biodiesel blends resulted in less oxigen and same level of CO2. Specific fuel consumption was sensitive to biodiesel and was found to be higher proportionally to the biodiesel amount in every blend. Amount of biodiesel did not produce always proportional results.

Existem motivações de ordem ambiental e energética para que combustíveis renováveis sejam cada vez mais utilizados. O biodiesel é uma das alternativas renováveis à utilização de óleo diesel de origem fóssil, e sua utilização tem crescido no mundo. No Brasil, existe uma propensão muito positiva para o cultivo de oleaginosas, e o biodiesel aparece como proposta de solução ambiental, energética e social. A utilização de biodiesel no Brasil tem sido crescente desde 2004 e torna-se-á compulsória a partir de 2008. Nas lavouras não é diferente, e a utilização do biodiesel no maquinário agrícola já é realidade em diversas fazendas do país. A fim de se conhecer as consequências em termos de desempenho, devido a utilização de biodiesel em motores do ciclo diesel, estudos se fazem necessários. O presente trabalho teve por objetivo comparar desempenho, consumo específico e emissão de gases de um motor originalmente concebido para funcionar com óleo diesel de origem mineral, utilizando-se misturas de biodiesel de soja e de nabo forrageiro em proporções de até 20 % em seu volume. Os ensaios foram realizados no laboratório de motores da Delphi, em Piracicaba, SP, em dinamômetro de motor assíncrono, em célula de medição automatizada. Não foram observadas diferenças significativas no desempenho do motor ao funcionar com misturas de biodiesel comparativamente ao diesel padrão. O HC foi maior para misturas de biodiesel em toda a faixa de operação do motor. O NOx mostrou-se maior apenas na faixa inicial de operação. Para o CO não se pôde atribuir uma tendência de emissões de gases relacionada ao biodiesel. Para os gases não poluentes, o biodiesel produziu menor oxigênio que o diesel padrão e mesmo nível de CO2. O consumo específico de combustível mostrou-se sensível à adição de biodiesel, sendo maior proporcionalmente às taxas de biodiesel utilizadas. A taxa de biodiesel adicionada nem sempre resultou em tendência proporcional de alteração nos resultados. / There are environmental and energetic motivations that lead to a higher usage of renewable fuels. Biodiesel is one of the renewable alternatives to the fossil diesel fuel and its usage has been growing worldwide. In Brazil there are positive conditions for the oil energetic agriculture and biodiesel emerges as a proposal for environemental, energetic and social solution. Utilization of biodiesel has been increasing since 2004 and will become obligatory starting 2008. Agricultural utilization of biodiesel on machines is already a reality in several farms in Brazil. In order to better understand the consequences in terms of engine performance due to biodiesel utilization in diesel engines, research is necessary. This work had the objective of comparing performance, specific fuel consumption and gas emissions of an engine originally designed to burn fossil diesel, using soy and forage turnip biodiesel / diesel blends in proportions up to 20 % in volume. Tests were performed at Delphi engine laboratories in Piracicaba, SP, in assincronous dynamometers, in a computer controlled test cell. No significative performance differences were found when running with biodiesel blends if compared to standard diesel. HC was higher with biodiesel blends for all engine operation range. NOx was higher only at initial engine operation range. It was not possible to attribute a tendence to CO emission related to biodiesel usage. For non-pollutant gases, biodiesel blends resulted in less oxigen and same level of CO2. Specific fuel consumption was sensitive to biodiesel and was found to be higher proportionally to the biodiesel amount in every blend. Amount of biodiesel did not produce always proportional results.

<p>Continuously throughout the process of developing Engine Control Units (ECU), the ECU and its control functions need to be dimensioned and tested for the engine itself. Since interaction between an ECU and a physical engine is both expensive and inflexible, software models of the engine are often used instead. One such test system, where an ECU interacts with software models, is called Hardware-in-the-Loop (HiL). This thesis describes a model constructed to facilitate implementation on a HiL testbed. </p><p>The model, derived in Matlab/Simulink, is a Cylinder-by-Cylinder Engine Model (CCEM) reconstructing the angle synchronous torque of a diesel engine. To validate the model, it has been parameterised for the DaimlerChrysler engine OM646, a straight turbocharged four cylinder diesel engine, and tested towards measured data from a Mercedes-Benz C220 test vehicle. Due to hardware related problems, validation could only be performed for low engine speeds where the model shows good results. Future work around this theme ought to include further validation of the model as well as implementation on HiL.</p>

<p>Stricter emission legislation for heavy trucks in combination with the customers demand on low fuel consumption has resulted in intensive technical development of engines and their control systems. To control all these new solutions it is desirable to have reliable models for important control variables. One of them is the air mass-flow, which is important when controlling the amount of recirculated exhaust gases in the EGR system and to make sure that the air to fuel ratio is correct in the cylinders. The purpose with this thesis was to use system identification theory to develop a model for the air mass-flow through the compressor. First linear black-box models were developed without any knowledge of the physics behind. The collected data was preprocessed to work in the modeling procedure and then models with one or more inputs where built according to the ARX model structure. To further improve the models performance, non-linear regressors was developed from physical relations for the air mass-flow and used to form grey-box models of the air mass-flow.In conclusion, the performance was evaluated through comparing the estimated air mass-flow from the best model with the estimate that an extended Kalman filter together with a physical model produced.</p> / <p>Hårdare utsläppskrav för tunga lastbilar i kombination med kundernas efterfrågan på låg bränsleförbrukning har resulterat i en intensiv utveckling av motorer och deras kontrollsystem. För att kunna styra alla dessa nya lösningar är det nödvändigt att ha tillförlitliga modeller över viktiga kontrollvariabler. En av dessa är luftmassflödet som är viktig när man ska kontrollera den mängd avgaser som återcirkuleras i EGR-systemet och för att se till att kvoten mellan luft och bränsle är korrekt i motorns cylindrar. Syftet med det här examensarbetet var att använda systemidentifiering för att ta fram en modell över luftmassflödet förbi kompressorn. Först togs linjära svartboxmodeller fram utan att ta med någon kunskap om den bakomliggande fysiken. Insamlade data förbehandlades för att passa in i modelleringsproceduren och efter det skapades i enlighet med ARX-modellstrukturen modeller med en eller flera insignaler. För att ytterligare förbättra modellernas prestanda togs icke-linjära regressorer fram med hjälp av fysikaliska relationer för luftmassflödet. Dessa användes sedan för att skapa gråboxmodeller av luftmassflödet. Avslutningsvis utvärderades prestandan genom att det estimerade luftmassflödet från den bästa modellen jämfördes med det estimat som ett utökat kalmanfilter tillsammans med fysikaliska ekvationer genererade.</p>

In this Masters Thesis emissions to water from diesel engines in pleasure boats when driven with alternative fuels have been investigated. Two alternative fuels, Fischer-Tropsch-diesel (FT-diesel) and a blend of FT-diesel and rapeseed methyl ester (RME) have been compared with diesel of Swedish environmental class 1 (diesel EC1). The alternative fuels have been compared using two older marine diesel engines, and water samples have been taken from the water in the exhaust system before the exhaust compounds reaches the recipient. The water samples have been analysed with gas chromatography (GC) and mass spectrometry (GC/MS), to analyse volatile and semi volatile compounds including aldehydes and ketons. To investigate the acute toxicity of the exhaust water a 24 h ecotoxicological test was preformed with the crustacean Artemia fransiscana. The results showed considerable differences in emissions of poly aromatic hydrocarbons (PAHs) and alkylated benzenes. From diesel EC1, the amounts of PAHs and alkylated benzenes were significantly higher than from pure FT-diesel and FT-diesel containing 20 % of RME. Pure FT-diesel generated the lowest amounts of PAH and alkylated benzenes. The FT-diesel containing 20 % RME generated higher amounts of benzene than diesel EC1. FT-diesel and FT-diesel with a 20 % blend of RME generated the same amount of acetone, which in turn was higher than the concentration of acetone in the exhaust water, using diesel EC1. Based on the analysis, FT-diesel is the best alternative from an exhaust emission point-of-view, concerning both the amounts and the difference in chemical composition of the combustion products released into the water. The ecotoxicological test showed no effect on the test organism using either of the samples. / Fritidsbåtsintresset är stort i Sverige och båtlivet betyder mycket för många svenskar. Tyvärr är användningen av fritidsbåtar förknippad med en rad miljöproblem. Avgasutsläpp till vatten och luft från fritidsbåtsmotorer påverkar den lokala miljön avsevärt. Gammal teknik med dålig förbränning används fortfarande i stor utsträckning. På kort sikt, innan den gamla tekniken är utbytt, är det viktigt att den äldre motorparken använder miljöanpassade bränslen för att utsläppen till sjöar och hav ska bli så skonsamma som möjligt. Det är dock viktigt att utvärdera miljöpåverkan av dessa alternativa bränslen, så att det verkligen är ett bättre alternativ ur miljösynpunkt. I detta examensarbete har utsläpp till vatten från dieselinombordsmotorer vid drift med olika bränslen undersökts. Två miljöanpassade dieselbränslen; FT-diesel (Fischer-Tropsch) och en procentinblandning av rapsmetylester (RME) i FT-diesel, har jämförts med diesel av svensk miljöklass 1 (MK1). Bränslena har testkörts i två äldre, marina dieselmotorer och prover har tagits på det avgasblandade kylvattnet innan det når recipienten. Det avgasblandade kylvattnet har analyserats med avseende på delvis flyktiga och flyktiga föreningar, aldehyder samt ketoner. Analyserna har skett med gaskromatografi och masspektormetri (GC/MS-screening) på externt laboratorium. För att testa avgasvattnets akuta giftighet har även ett akut (24h) ekotoxikologiskt test utförts på kräftdjuret Artemia fransiscana. Analysresultatet visade skillnad i utsläpp av polyaromatiska kolväten (PAH) och alkylbensener. Vid körning med diesel MK1 genererades betydligt högre halter av PAH:er och alkylbensener, än vid körning med FT-diesel och FT-diesel med 20 % inblandning av RME. Ren FT-diesel gav de lägsta halterna av PAH:er och alkylbensener. Utsläppshalterna av bensen uppvisade inte lika stor skillnad mellan de olika bränslena. Blandningen FT-diesel med 20 % RME gav lite högre halter bensen än vad diesel MK1 gjorde. Ren FT-diesel uppvisade lägst halt bensen. Utsläpp av aceton visade sig vara lika för FT-diesel och FT-diesel med 20 % RME och gav högre halter än vad diesel MK1 gjorde. Baserat på analysresultaten är FT-diesel det bästa bränslet ur emissionssynpunkt med avseende på vilka ämnen som hamnar i vattenfasen. Det ekotoxikologiska testet visade ingen skillnad mellan de olika bränslena. Avgasvatten från bränslena hade inte någon akut toxisk effekt på testdjuret.

Continuously throughout the process of developing Engine Control Units (ECU), the ECU and its control functions need to be dimensioned and tested for the engine itself. Since interaction between an ECU and a physical engine is both expensive and inflexible, software models of the engine are often used instead. One such test system, where an ECU interacts with software models, is called Hardware-in-the-Loop (HiL). This thesis describes a model constructed to facilitate implementation on a HiL testbed. The model, derived in Matlab/Simulink, is a Cylinder-by-Cylinder Engine Model (CCEM) reconstructing the angle synchronous torque of a diesel engine. To validate the model, it has been parameterised for the DaimlerChrysler engine OM646, a straight turbocharged four cylinder diesel engine, and tested towards measured data from a Mercedes-Benz C220 test vehicle. Due to hardware related problems, validation could only be performed for low engine speeds where the model shows good results. Future work around this theme ought to include further validation of the model as well as implementation on HiL.

Mit dieser wissenschaftlichen Arbeit wurde eine geschlossene Kette von Versuchsträger und Messtechniken geschaffen, die eine detaillierte und grundlegende Analyse der dieselmotorischen Gemischbildung und Verbrennung von der Ausbildung des Sprays in der kalten Einspritzkammer über die Detektion der Kraftstoffverdampfung in der heißen Einspritzkammer und der spektralen Analyse der Verbrennung des Kraftstoffes in den verschiedenen Wellenlängenbereichen im Transparentmotor ermöglichen. Für eine richtige Interpretation der optischen Messungen ist die quantitative Analyse des Verbrennungsprozesses im Einzylinder-Forschungsmotor hinsichtlich der Abgasemissionen und des Wirkungsgrades der Verbrennung unentbehrlich. So zeigte die optische Grundvermessung der Einspritzdüsen mit den unterschiedlichen Spritzlochgeometrien in der kalten Einspritzkammer unter der Anwendung der Streulichtmesstechnik eine sehr gute Strahlsymmetrie des Sprays während des Einspritzvorganges und eine sehr gute Reproduzierbarkeit der Einspritzvorgänge. Dies liegt unter anderem in der Bauform der Einspritzdüse mit Sackloch begründet. Weiterhin wurde festgestellt, dass eine Erhöhung des Durchflusskoeffizienten des Spritzloches ein kompakteres Spray mit einer höheren Eindringgeschwindigkeit und düsenfernerem Strahlaufbruch generiert. Die Versuche zum Verdampfungsverhalten des Kraftstoffsprays in der heißen Einspritzkammer unter Einsatz der kombinierten Streulicht- und Schattenmesstechnik zeigten für die Spritzlochgeometrien mit erhöhtem Durchflusskoeffizienten eine Verlagerung des verdampften Kraftstoffvolumens in düsenferne Gebiete und eine Erhöhung der Eindringtiefe des flüssigen Kraftstoffes. Die Anwendung der Streulichtmesstechnik zur Detektion des flüssigen Kraftstoffes und der Einsatz von Kamerasystemen zur Erfassung des Eigenleuchtens im ultravioletten Spektralbereich und im sichtbaren Spektralbereich der Verbrennung im Transparentmotor belegen eine deutliche Intensivierung des Strahlaufbruchs in düsenfernen Bereichen für die Einspritzdüsen mit steigendem Durchflusskoeffizienten. Das führt zu einer verbesserten Gemischaufbereitung unter der Ausnutzung des in diesen Gebieten vermehrt zur Verfügung stehenden Sauerstoffes. Im Emissionspunkt mit hohem Einspritzdruck wird die Brennraumwand intensiv in die Gemischaufbereitung und die Verteilung des Kraftstoffdampf-Luft-Gemisches eingebunden. Die Einführung zusätzlicher motorrelevanter Parameter wie Voreinspritzung und Abgasrückführung im Emissionspunkt verdeutlichen die Möglichkeit der Absenkung der Rußemissionen beim Einsatz von Spritzlöchern mit erhöhtem Durchflusskoeffizienten. In diesen Betriebspunkten mit geringer Motorlast wird mit der weiteren Optimierung der Strömungsverhältnisse im Spritzloch durch den Einsatz der ks-Spritzlochgeometrie die Gemischbildung und Verbrennung so intensiviert, dass eine nochmalige Senkung der Rußemissionen erzielt werden konnte. Durch den Einsatz von Einspritzdüsen mit ks-Spritzlochgeometrie kann gegenüber Einspritzdüsen mit konischen Spritzlöchern eine positive Beeinflussung der dieselmotorischen Gemischbildung und Verbrennung in allen untersuchten Lastpunkten nachgewiesen werden. So erzielt man im Schwärzungspunkt mit der Erhöhung des Durchflusskoeffizienten sinkende Rußemissionen und eine Erhöhung des Wirkungsgrades der Verbrennung. Im Leistungspunkt konnte ein Abnehmen der Rußemissionen bei einem vergleichbaren Wirkungsgrad der Verbrennung festgestellt werden. Die durchgeführten Untersuchungen zeigten, dass die Spritzlochgeometrie der Einspritzdüse einen wichtigen Parameter darstellt, die Wechselwirkung des Sprayaufbruchs und die Ausnutzung der Ladungsbewegung im Brennraum mit der Interaktion des aufbereiteten Kraftstoffes an der Brennraumwand so zu steuern, dass die Abgasemissionen schon innermotorisch gesenkt und der Aufwand an Abgasnachbehandlungssystemen auf ein Minimum reduziert werden kann.

Um die beiden Hypothesen, dass (1) die Anzahl der Doppelbindungen der veresterten Fettsäuren einen Einfluss auf die Mutagenität der DME hat, und (2) dass die Oxidation (künstliche Alterung) verschiedener FAME und Blends höhere Mutagenität der DME bewirkt, zu untersuchen, wurden Abgasproben der folgenden Kraftstoffe verwendet: DK, PME, RME, LME, B20, B20alt, B20E2, B20altE2, RMEalt. Die Abgasproben wurden über Testläufe mit einem Mercedes-Benz OM 906 Euro-IIIMotor, der im ESC Testzyklus betrieben wurde, gewonnen. Die Mutagenität der Abgasproben wurde mittels des Ames-Tests untersucht. Sowohl die Positiv- als auch die Negativkontrollen bestätigten, dass die Reagenzien und Teststämme für die Versuche geeignet waren. Die Ergebnisse zeigten, dass sich die unter Punkt 1.5.1 (S. 17) beschriebene Hypothese, dass die Anzahl der Doppelbindungen der veresterten Fettsäuren einen Einfluss auf die Mutagenität der DME hat, bestätigte. Sowohl bei den Kondensaten, als auch den Partikulaten konnte gezeigt werden, dass die DME der FAME mit der geringeren Anzahl an mehrfach ungesättigten Fettsäuren signifikant geringer mutagen waren, als die DME der FAME mit der höheren Anzahl an mehrfach ungesättigten Fettsäuren. So ergab sich eine Reihenfolge der FAME mit aufsteigender Mutagenität ihrer DME: PME < RME < LME. Dieses Ergebnis war vor allem bei den Kondensaten in beiden Teststämmen (TA98, TA100) mit als auch ohne metabolische Aktivierung und bei den Partikulaten im Stamm TA98 ohne metabolische Aktivierung zu sehen. Die zweite Hypothese, dass die Oxidation (künstliche Alterung) verschiedener FAME und Blends höhere Mutagenität der DME bewirkt, wurde widerlegt. Zur Untersuchung dieser Hypothese wurden neben FAME (RME, RMEalt) folgende Blends verwendet: B20, B20alt, B20E2, B20altE2. Es konnten zwei signifikante Unterschiede erzielt werden, die jedoch für einen Beweis nicht ausreichten. Zusätzlich traten die signifikanten Unterschiede nicht im selben Teststamm auf und die Abgase der gealterten Form waren nicht durchgängig mutagener als die Abgase der nicht gealterten Form. Der Beweis eines signifikanten Unterschiedes, dass die Oxidation von FAME höhere Mutagenität der DME der dadurch gealterten FAME hervorruft, war daher nicht möglich. Weiterhin wurde ein Blend mit 2% Ethanol und 2% Butanol verschnitten. Der erhoffte Effekt der Alkoholadditivierung, eine Homogenisierung des FAME-Anteils durch Sedimentauflösung von oxidativen Abbauprodukten von FAME-Blends zu bewirken, blieb ebenso aus. Bei der Betrachtung der GPM zeigte sich, dass die FAME nicht die höchste GPM, aber die größte LOF besitzen. Dies spiegelte sich in der Mutagenität der DME der FAME verglichen mit denen des DK wieder. DK hatte zwar einen höheren Wert der GPM, aber einen kleineren Anteil der LOF. Die Abgase der FAME zeigten sich tendenziell mutagener als die des DK, jedoch ohne signifikante Ergebnisse. Dieser Effekt war v.a. bei den Kondensaten zu sehen. Die erhöhte Mutagenität der FAME-Abgase gegenüber den DK-Abgasen lässt sich anhand verschiedener Hypothesen erklären, die aber noch nicht ausreichend untersucht oder bewiesen sind.