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1
Thore, Petra. ""Wer bist du hier in dieser Stadt, in diesem Land, in dieser Welt" : die Identitätsbalance in der Fremde in ausgewählten Werken der deutschsprachigen Migrantenliteratur /." Uppsala : Uppsala Universitet, 2004. http://catalogue.bnf.fr/ark:/12148/cb40051779z.
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Thore, Petra. ""wer bist du hier in dieser stadt, in diesem land, in dieser neuen welt" : Die Identitätsbalance in der Fremde in ausgewählten Werken der deutschsprachigen Migrantenliteratur." Doctoral thesis, Uppsala University, Department of German, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4232.
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The central concern of this thesis is to investigate the development of the personal identity of the main characters in four novels, a novella, and a short-story, written in German by authors from different countries who have immigrated to post World War II Germany and Switzerland. Earlier research concerning these identity processes is reviewed with emphasis on the relevance of the different theoretical models of development of personal identity used. A model called “identity-balance”, first described by the German sociologist Lothar Krappmann, is used in analysing the changes in personal identity. This model is preferred because of Krappmann’s strong emphasis on interaction, process, and openness. Based upon the results of the interpretations a modification of Krappmann’s model is suggested in order to better shed light upon identity processes following migration. As languages are shown to play a great role in these processes, aspects concerned with multilingualism and the part languages play in the “identity-balance” are discussed throughout the thesis. The textual interpretations reveal the connection between three lines of change: changes in personal identity, changes in society following migration, and changes in the field of literature.
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Dieser, Markus. "Ecosystem dynamics and temporal variations in a microbially dominated, coastal antarctic lake." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/dieser/DieserM1209.pdf.
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This study investigated the microbial ecology of Pony Lake, Antarctica. The main objectives of this research were to 1) characterize physicochemical parameters in Pony Lake during the transition from ice covered to ice free, 2) highlight seasonal and inter-seasonal alterations in lake parameters, 3) relate the physicochemical conditions in the ice and water column to microbial processes and community structure, 4) characterize the effects of phototransformation of dissolved organic matter (DOM) on its bioavailability to bacteria, and 5) demonstrate the role of carotenoid pigments in protecting cells against environmental stresses. Also included are results from three McMurdo Dry Valley lakes on the survivability of microbes encapsulated within the lake ice covers. The results of this study highlight the sensitivity of Antarctic environments and the close coupling of environmental conditions and biological processes. Inter-seasonal differences in weather conditions and snow accumulation strongly affected the physicochemistry of this lacustrine system. Biological processes were closely tied to the physicochemical lake conditions. As a consequence planktonic abundances, production rates, and community structure evolved distinctly in each year. Bacterial production was regulated by the quality of DOM. Whereas nutrient availability appeared to play a minor role in eutrophic Pony Lake water, it became more critical for microbial communities found within the ice column of Antarctic lakes. Especially in the ice cover of the McMurdo Dry Valley lakes, enhanced microbial diversity and survivability was associated with particles (nutrient enriched micro-zones) within an otherwise ultra-oligotrophic habitat. In Pony Lake ice, microbial activity and community structure differed with respect to different strata within the ice column, induced by freeze-concentration of solutes, bioavailability of DOM, and oxygen gradients. A comparison of carotenoid pigmented and non-pigmented heterotrophic bacteria indicated that pigmentation provides enhanced resistance to environmental stresses such as freeze-thaw cycles or solar radiation. Collectively, the Pony Lake data demonstrated that microorganisms that persist throughout the year were able to survive much more severe conditions while entrapped within the ice compared to those observed in the lake water during summer months. Further, this study contributes to a better understanding of the biogeochemical carbon cycle in a microbially dominated system.
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Sayatz, Ulrike. "Von Denkmälern und Denkmalen, Balkons und Balkonen, Anfängen dieses Jahres und diesen Jahres: Die Vermittlung von System, Norm und Variation in der Schule am Beispiel der Nominalflexion." Universität Potsdam, 2009. http://opus.kobv.de/ubp/volltexte/2009/3705/.
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Erastova, Valentina. "Molecular simulation studies of diesel and diesel additives." Thesis, Durham University, 2012. http://etheses.dur.ac.uk/6361/.
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As diesel fuel is cooled down, waxes are deposited, which are made up from crystals of long chain n-alkanes. Wax depositions are undesirable, since they can block anything from filters in diesel engines to pipelines. It is already known that wax formation can be inhibited by the addition of wax crystal modifiers to diesel fuel. This thesis em- ploys computational models at atomistic and coarse-grained levels to investigate the crystallisation of diesel fuel and the effect of additives upon the crystallisation process. In the first results section, a model for diesel fuel is introduced and a strategy for investigating its crystallisation is developed. Crystallisation was observed from pure n-tricosane, binary and tertiary mixtures of paraffins of similar chain lengths. These systems were found to crystallise into hexagonally arranged lamellae. The presence of different length alkanes was found to create gauche disorders, leading to the formation of lamellar layers with softer edges. It was also found that crystal growth could be simulated more efficiently in the presence of a positionally restrained crystal, acting as a nucleation centre. Subsequently, crystallisation of paraffins, and the solvent effect upon it, was studied. This allowed to establish behavioural trends characteristic for aromatic and aliphatic solvents. Finally, paraffin crystallisation in the presence of four common additives was investigated. A common mode of action for these additives was identified, based upon partial co-crystallisation of additive alkyl chains and paraffin molecules. The main drawback of atomistic simulation is the computational cost, which limits both the time and length scales accessible on modern computers. In order to overcome these inherent limitations, a coarse grained model was developed for a range of n-alkanes. Remarkably, the model shows transferability over 120 K, preserving thermodynamic and structural properties of both melt and crystal. In summary, this thesis provides a detailed picture of diesel crystallisation at a molecular level, and provides new insights into the mechanism of action of a number of common diesel additives.
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EGUSQUIZA, JULIO CESAR CUISANO. "EXPERIMENTAL INVESTIGATION OF A DIESEL CYCLE ENGINE OPERATING ON DUAL-FUEL MODE: DIESEL / ETHANOL AND DIESEL / GAS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=17103@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRONo presente trabalho, ensaios experimentais de um motor do ciclo Diesel consumindo etanol hidratado ou gás natural em substituição parcial ao óleo diesel, foram realizados. Os objetivos principais foram verificar as influências dos combustíveis alternativos e avaliar as técnicas do avanço da injeção do diesel e da restrição parcial do ar de admissão, em relação aos parâmetros característicos da combustão, desempenho e emissões. Com base nos dados do diagrama pressão-ângulo de virabrequim, foi possível analisar alguns parâmetros característicos da combustão, tais como o início da combustão, a máxima taxa de elevação de pressão e o pico de pressão. Os parâmetros do desempenho e emissões do motor foram analisados através do rendimento térmico e as concentrações de monóxido de carbono, hidrocarbonetos, material particulado e óxidos de nitrogênio. Os resultados obtidos mostraram que as técnicas avaliadas no modo bicombustível junto com as elevadas taxas de substituição do óleo diesel favoreceram a melhor queima dos combustíveis alternativos, refletindo-se favoravelmente em menores emissões de CO e MP, além de um pequeno aumento no rendimento térmico do motor. No entanto, houve também um acréscimo nas emissões de NOX e, no caso específico do avanço da injeção, foi notado um maior ruído gerado pelo motor.
In this report, experimental tests of a Diesel cycle engine running with hydrous ethanol or natural gas with partial substitution for diesel fuel were performed. The main objectives were to verify the influence of alternative fuels and evaluate the advancing of diesel injection timing and the air partial restriction, regarding the characteristic parameters of combustion, performance and emissions. Based on data from the pressure-crank angle diagram, it was possible to analyze some characteristic parameters of combustion, such as the start of combustion, the maximum rate of pressure rise and peak pressure. The parameters of the engine performance and emissions were analyzed through the thermal efficiency and the concentrations of carbon monoxide, hydrocarbons, particulate matter and nitrogen oxides. The results showed that the techniques evaluated in dual fuel mode with higher rates of substitution of diesel fuel favored a better burning of the alternative fuels, reflecting favorably in lower emissions of CO and PM, and also in a small increase in the engine thermal efficiency. However, there was also an increase in NOX emissions and, in the specific case of the advanced injection timing, it was noted a louder noise generated by the engine.
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Mirmohammadsadeghi, Mahmoudreza. "Investigation of diesel-ethanol and diesel-gasoline dual fuel combustion in a single cylinder optical diesel engine." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17436.
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Ever growing population and increased energy consumption across all industries has resulted in higher atmospheric concentration of the greenhouse gases (GHG) and therefore an increase in the planet's average temperature, which has led to increasingly demanding and more strict legislations on pollutant sources, and more specifically, the automotive industry. As a consequence of all this, the demand for research into alternative energy sources has greatly increased. In this study combustion characteristics, engine performance, and exhaust emission of diesel-ethanol and diesel-gasoline are investigated in an optical direct injection diesel engine. In particular, effects of different substitution ratios and diesel injection strategies are studied when the total fuel energy is kept constant. The three main substitution ratios used in this study include 45% (45% of fuel energy from port-injected ethanol/gasoline and 55% from direct injection diesel), 60%, and 75%. The engine used for this investigation is a Ricardo Hydra single cylinder optical engine running at 1200 rpm. In-cylinder pressure measurement is used for calculating all engine parameters, heat release rate, and efficiency. In addition to the thermodynamic analysis of the combustion parameters, high speed camera was used alongside with a copper vapor laser or the high speed image intensifier in the high speed video imaging for the optical analysis of the effect of the above-mentioned parameters on autoignition and combustion processes, while Horiba particulate analyser and AVL smoke meter were utilized in monitoring and recording emissions for every tested condition. Depending on the testing conditions, such as injection strategy and intake conditions, both dual-fuel operations were able to deliver high efficiency and improved emissions compared to that of a pure diesel engine operation, with the diesel-gasoline operation offering more consistency in improved thermal efficiency, and the diesel-ethanol operation delivering lower emission output. The optical analysis of the combustion represents the main difference in the flame propagation, distribution and quality for each substitute fuel and its substitution percentage, as well as the condition under examination.
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Renman, Emil. "Diesel Dubbelbränsle Teknologi." Thesis, KTH, Maskinkonstruktion (Inst.), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-100202.
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The work covered in this report includes a literature study of the diesel dual fuel technology (hereinafter referred to as DDF). The literature study covers earlier work that has been done regarding the use of compressed natural gas (CNG) and diesel in a DDF system. Moreover a one cylinder research diesel engine was fitted with a CNG fuel system for experimental testing. The installation of the engine and the test cell is described. Results from the tests are presented covering emissions, heat release and pressure traces from the DDF-concept. During the literature study it was found that most research was related to heavy duty diesel engines. The research papers covered in this report describes the main areas of interests in DDF engines including injection strategies, amount of diesel fuel ratio, low load performance, knocking, emission levels and the effect of the injector geometry. When looking at the concept of DDF engines, the main problems are poor low load characteristics and proneness to knock at high loads and emission levels. A major concern is the ability to handle the high levels of hydrocarbon emissions especially at low loads associated with low exhaust gas temperatures. The main focus of the work presented in this report has been on completing the installation of a CNG system and making it work. Although, experimental testing was performed and an injection sweep and an attempt to increase load was tested. Results from the injection sweep showed that the choice of SOI (start of injection) and the injection strategy could most likely be improved at low loads. Looking at a single injection strategy moving from SOI at 5 oBTDC to 55o BTDC lowered the nitrous oxide emissions by more than 90 % and at the same time increasing net torque. However, this is just an example of what influence the SOI has on one emission. It is believed that a multi-injection strategy could reduce the engine out emissions and at the same time improving combustion efficiency at low loads. For further work recommendations and theories of the author are presented at the end of the report.Denna rapport inkluderar en litteraturstudie inom området ”Diesel Dual Fuel”-motorer (hädanefter kallat DDF-motorer). Rapporterna som redovisas i litteraturstudien behandlar DDFmotorer med CNG (naturgas) som huvudbränsle och diesel som tändkälla. Utöver litteraturstudien så byggdes en CNG bränsleanläggning. Bränsleanläggningen och provcellen där testerna utfördes är beskrivna i rapporten tillsammans med resultat från körningarna. Redovisade resultat visar emissioner, värmefrigörelse och cylindertryckskurvor vid körning med DDF. Litteraturstudien visade att den mesta forskningen gjorts med tunga dieselmotorer. Forskningsrapporterna som redovisas beskriver de huvudsakliga intresseområdena inom DDFteknologin. Dessa inkluderar; insprutningsstrategier, diesel/naturgas-förhållande, låglastegenskaper, knack, emissionsnivåer och dieselinsprutarens utförandes påverkan på förbränningen. DDF-motorer lider generellt av dåliga låglastegenskaper och begränsningar vid högre laster p.g.a. knack och problem med emissionsnivåer. En stor utmaning är att kunna hantera de ökade utsläppen av kolväten, speciellt vid låga laster kombinerat med låga avgastemperaturer. Det huvudsakliga arbetet har varit att slutföra och validera installationen av bränsleanläggningen. Utöver installationen och valideringen utav den så utfördes ett insprutningsvinkelsvep med dieselinsprutningen och ett försök att öka lasten med ökad mängd CNG. Resultat från insprutningsvinkelsvepet visade att valet av insprutningsvinkel och insprutningsstrategi kan förbättras. Vid en låglastpunkt som utvärderades gav insprutningsvinkelns förändring från 5 o FÖD till 55oFÖD en minskning av NOx med mer än 90 % och samtidigt en momentökning. Detta är endast ett exempel på hur valet av insprutningsvinkel påverkar ett emissionsämne. Det anses dock troligt att en flerinsprutningsstrategi skulle kunna minska råemissionerna och samtidigt minska specifika bränsleförbrukningen vid låga laster. För fortsatt arbete så presenteras rekommendationer och teorier gällande DDF-motorer och CNG-bränsleanläggningen i slutet av rapporten.
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Rigoni, Barbara <1993>. "Provocative advertising : Diesel." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/11774.
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The object of this work is to improve the knowledge about the advertising strategies of one of the most well-known, innovative and worldwide distributed Italian brand in the fashion industry: Diesel. I choose Diesel because this brand, founded by Renzo Rosso, has been under the spotlight for its attitude to make the most controversial and provocative advertising campaigns.
Since the beginning, Diesel represented an upstream and innovative brand, following the leading of the owner Renzo Rosso who has always pointed out his belief in freedom and the willingness to do whatever he wanted without any filter. It is exactly this rebellious halo that is directly reflected on the way the brand advertises itself.
Indeed, through the reconstruction of Diesel history I will examine its advertising characteristics and evolution in the years in order to figure it out whether those has a positive or negative response on the success of the brand.
First, I will introduce all the general characteristics proper of the Italian fashion industry, in order to present the scenario in which the firm was born. Significant attention will be put on the marketing and advertising field, explaining how fashion publicity evolved and changed in the last decades. In particular, I focused on the advertising flow made by provocative and dumb images that can find its starting point in Benetton Campaigns by Oliviero Toscani at the beginning of the 80s.
After this background introduction, I will present the history of Diesel, focusing on its international evolution from a local small firm to a multinational one. Stressing the values, actions and development of the firm has been useful to highlight and understand the winning moves that made Diesel such a successful worldwide case.
Of course a key role in the growth of the company has been played by the founder himself. Renzo Rosso has been able to position Diesel exactly where it wanted it to be: a young and international brand addressed to young and bold people. Recently, Rosso added a crucial component to the Diesel team, the creative director: Nicola Formichetti. I decided to focus my attention on these two characters because they represent, at the best, the brand identity and vision. After the presentation of ”these two”, I will give a general description of the brand and, in particular of its Identity and beliefs. These are, as a matter of fact, core factors that made this brand grow till where it is nowadays, reaching the target that best suits it.
What is even more important of this brand is that it does not simply sell denim products, but it suggests a lifestyle, someone you can be when wearing Diesel clothes.
This lifestyle is the one proposed in the advertising campaigns. I will explain the deep philosophy behind the way Diesel advertises and how this philosophy has been maintained along all the history of the brand. Of course, the advertising campaigns changed through the years: I decided to divide them into macro historical section in order to clearly show Diesel reactions and moves toward the years.
Eventually I decided to carry out an empirical research to see whether if Darren Dahl's theory about the effectiveness of provocative advertising in attracting people's attention was founded. Therefore, I submitted a questionnaire, created ad hoc for the purpose, and I submitted it to a sample. From this I have collected and analyzed the data that, even though they were not obtained from a statistically selected sample, they resulted as being very interesting.
It has been interesting to see the different publicities changing and evolving according to the different historical contexts, world streams and circumstances.
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Wallace, Scott J. "Diesel Engine Energy Balance Study Operating on Diesel and Biodiesel Fuels." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1212586902.
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Canfield, C. Alan. "Effects of diesel-water emulsion combustion on diesel engine NOx emissions." [Florida] : State University System of Florida, 1999. http://etd.fcla.edu/etd/uf/1999/amg2169/canfield%5Fc.pdf.
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Thesis (M.S.)--University of Florida, 1999.Title from first page of PDF file. "X" in "NOx" in title is subscript. Document formatted into pages; contains vii, 85 p.; also includes graphics. Vita. Includes bibliographical references (p. 79-84).
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Silveira, MÃrcia Bezerra. "Estudo do sistema Ãlcool + biodiesel + diesel (AB-Diesel): equilÃbrio e propriedades termofluidodinÃmicas." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=10003.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorA reduÃÃo das emissÃes nos motores a diesel à estudada por muitos autores e a modificaÃÃo da composiÃÃo do combustÃvel à uma das alternativas mais abordadas. Neste contexto, o estudo da mistura ab-diesel (Ãlcool + biodiesel + diesel) tem atraÃdo atenÃÃo devido algumas de suas caracterÃsticas, tais como, calor de combustÃo semelhante ao do diesel âpuroâ e reduÃÃo da emissÃo de material particulado e gases tÃxicos. O Ãleo diesel à definido como um combustÃvel derivado do petrÃleo, constituÃdo basicamente por hidrocarbonetos e em baixas concentraÃÃes por compostos sulfurados, nitrogenados e oxigenados. A presenÃa dos compostos parafÃnicos na composiÃÃo do diesel dificulta a solubilidade de compostos polares, como os Ãlcoois, dessa forma o biodiesel foi estudado como um agente capaz de solubilizar o Ãlcool no diesel garantindo a formulaÃÃo de misturas mais estÃveis. A inserÃÃo desse combustÃvel derivado de biomassa renovÃvel constituÃdo por uma mistura de mono-alquil Ãsteres de Ãcidos graxos de origem vegetal, animal e Ãleos residuais contribui tambÃm para a melhora de algumas outras caracterÃsticas fÃsico-quÃmicas importantes na utilizaÃÃo dessa mistura como fonte de energia. A solubilidade dos sistemas pseudoternÃrios constituÃdos de diesel + biodiesel metÃlico de soja + metanol e diesel + biodiesel etÃlico de soja + etanol foi estudada atravÃs da construÃÃo de curvas de equilÃbrio lÃquido-lÃquido para duas temperaturas e observou-se que aumento da temperatura favoreceu a solubilidade dos componentes nos dois sistemas, contribuindo para formaÃÃo de uma maior regiÃo homogÃnea. Assim como jà era esperado, o sistema contendo etanol apresentou uma regiÃo homogÃnea bem maior que o sistema com metanol, uma vez que a solubilidade do primeiro no diesel à maior. As linhas de amarraÃÃo nÃo foram bem representadas pelos modelos termodinÃmicos NRTL e UNIQUAC. Dados de densidade e viscosidade foram determinados para os componentes puros/pseudopuros e para misturas pseudobinÃrias e pseudoternÃrias em vÃrias temperaturas e composiÃÃes, uma vez que o conhecimento dessas propriedades fÃsico-quÃmicas à essencial para a formulaÃÃo de uma mistura combustÃvel com caracterÃsticas dentro das especificaÃÃes. Os dados experimentais de densidade e viscosidade foram ajustados atravÃs de modelos de regressÃo para determinaÃÃo do seu comportamento em funÃÃo da temperatura e composiÃÃo e obteve-se um desvio padrÃo mÃximo de 0,0087 e 0,1962, respectivamente, ambos para o sistema de biodiesel metÃlico de soja + metanol. Densidade e viscosidade apresentaram comportamento linear e exponencial, respectivamente, com a temperatura. Como esperado, um aumento na temperatura diminuiu os valores de densidade e viscosidade para todos os sistemas estudados. Uma vez que nÃo à factÃvel obter experimentalmente dados de densidade e viscosidade em todas as condiÃÃes de interesse, mÃtodos para sua prediÃÃo/estimaÃÃo sÃo de grande interesse prÃtico e foram utilizados no presente trabalho. AlÃm da obtenÃÃo dos dados experimentais de densidade e viscosidade, foram realizados tambÃm, ensaios de estabilidade fÃsica de fases e ponto de fulgor para as misturas pseudoternÃrias. Observou-se que a estabilidade fÃsica foi influenciada principalmente pela temperatura e teor de Ãlcool e que para misturas do tipo Ãlcool + biodiesel + diesel o ponto de fulgor à dominado principalmente pela concentraÃÃo do Ãlcool.
The reduction of emissions from diesel engines has been studied by many authors and the modification of the fuel composition is one of the most discussed alternatives. In this context, the study of ab-diesel mixture (alcohol + biodiesel + diesel) has attracted attention due to some of its features, such as combustion heat similar to that of "pure" diesel and reducing the emission of particulates and toxic gases. Diesel oil is defined as a petroleum-derived fuel, constituted basically by hydrocarbons and at low concentrations for sulfur, nitrogen and oxygen. The presence of the paraffin compounds in diesel hamper the solubility of polar compounds, such as alcohols, thus biodiesel has been studied as an agent to solubilize the alcohol in diesel ensuring the formulation of stable mixtures. The insertion of this fuel derived from renewable biomass made up of a mix of mono-alkyl esters of fatty acids from vegetable, animal and residual oils contributes also to the improvement of some important physical-chemical characteristics in the use of this mixture as a source of energy. The solubility of the systems made up of diesel + methylic soybean biodiesel + methanol and diesel + ethylic soybean biodiesel + ethanol was studied through the construction of liquid-liquid equilibrium curves for two temperatures and it was observed that increased temperature favored the solubility of the components in the two systems, contributing to formation of a greater region homogeneously. As expected, the system containing ethanol showed a homogeneous region much larger than the system with methanol, since the solubility of the first diesel is increased. Tie-lines were not well represented by the NRTL and UNIQUAC. Density and viscosity data were determined for the pure/pseudo-pures components and pseudo-binary and pseudo-ternary mixtures at several temperatures and compositions, since the knowledge of physical-chemical properties is essential for the formulation of a mixture fuel with characteristics within specifications. Experimental data density and viscosity were adjusted through regression models for determining the behavior as a function of temperature and composition and obtained a maximum standard deviation of 0.0087 and 0.1962, respectively, both for the system of methylic soybean biodiesel + methanol. Density and viscosity showed linear and exponential behavior, respectively, with temperature. As expected, an increase in temperature decrease density and viscosity for all systems studied. Since it is not feasible to obtain experimentally density and viscosity data in all conditions of interest, methods for their prediction are of great practical interest and were used in this work. In addition to obtaining the experimental data of density and viscosity also were realized physics stability tests and flash point for pseudo-ternary mixtures. It was observed that the physics stability has been influenced mainly by the temperature and alcohol content and to blends of alcohol + biodiesel + diesel the flash point is mainly dominated by the alcohol concentration.
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Ting, Kui Lun. "Simulation of Wind-Diesel systems with differing diesel generators and energy storage." Thesis, Ting, Kui Lun (2015) Simulation of Wind-Diesel systems with differing diesel generators and energy storage. Other thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/27079/.
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This project was concerned about simulating wind-diesel systems with differing diesel generators, wind generation and energy storage. The simulating tool that was used in this project was Microsoft EXCEL.
A basic EXCEL ‘one hour’ energy flow model with one type of diesel generator was provided at the start of the project. The ‘one hour’ model contains average wind and load data recorded at each hour of the year.
This basic model was further developed to include:
Three types of diesel generator and,
Energy storage
Other than the basic ‘one hour’ model, different versions of the EXCEL model were also developed, which include:
‘Half hour’ model and,
‘Ten minute’ model
The only difference between the ‘half hour’ model and the ‘one hour’ model is that the average wind and load data are different. Therefore, there were not many changes in programming the ‘half hour’ model from the ‘one hour’ model. However, for the ‘ten minute’ model, the operation time of the diesel generators must be considered. Diesel generators do not turn on and off every 10 minutes and hence, the model must be programmed so that the diesel generators operate every 30 minutes or an hour. However, this was not done in the project due to time constraints. A ‘time step’ model was created instead to allow average wind and load data for any time step i.e. 2 hours data, 45 minutes data, 15 minutes data etc., to be pasted into the model.
The user-friendliness of the program was also improved to give better understanding by including simple instructions for users to use the program more conveniently.
The final enhanced one hour model with one type of diesel generator was then compared with HOMER to see how the results differ. The two programs are very different to each other in terms of both input details and simulation results.
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Silveira, Márcia Bezerra. "Estudo do sistema álcool + biodiesel + diesel (AB-Diesel): equilíbrio e propriedades termofluidodinâmicas." reponame:Repositório Institucional da UFC, 2013. http://www.repositorio.ufc.br/handle/riufc/5462.
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SILVEIRA, M. B. Estudo do sistema álcool + biodiesel + diesel (AB-Diesel): equilíbrio e propriedades termofluidodinâmicas. 2013. 124 f. Dissertação (Mestrado em Engenharia Química) - Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2013.Submitted by Marlene Sousa (mmarlene@ufc.br) on 2013-07-03T14:14:48Z No. of bitstreams: 1 2013_dis_mbsilveira.pdf: 4269872 bytes, checksum: ffd1bfcabd6d9d6e78f0fad0926c7ec3 (MD5)
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The reduction of emissions from diesel engines has been studied by many authors and the modification of the fuel composition is one of the most discussed alternatives. In this context, the study of ab-diesel mixture (alcohol + biodiesel + diesel) has attracted attention due to some of its features, such as combustion heat similar to that of "pure" diesel and reducing the emission of particulates and toxic gases. Diesel oil is defined as a petroleum-derived fuel, constituted basically by hydrocarbons and at low concentrations for sulfur, nitrogen and oxygen. The presence of the paraffin compounds in diesel hamper the solubility of polar compounds, such as alcohols, thus biodiesel has been studied as an agent to solubilize the alcohol in diesel ensuring the formulation of stable mixtures. The insertion of this fuel derived from renewable biomass made up of a mix of mono-alkyl esters of fatty acids from vegetable, animal and residual oils contributes also to the improvement of some important physical-chemical characteristics in the use of this mixture as a source of energy. The solubility of the systems made up of diesel + methylic soybean biodiesel + methanol and diesel + ethylic soybean biodiesel + ethanol was studied through the construction of liquid-liquid equilibrium curves for two temperatures and it was observed that increased temperature favored the solubility of the components in the two systems, contributing to formation of a greater region homogeneously. As expected, the system containing ethanol showed a homogeneous region much larger than the system with methanol, since the solubility of the first diesel is increased. Tie-lines were not well represented by the NRTL and UNIQUAC. Density and viscosity data were determined for the pure/pseudo-pures components and pseudo-binary and pseudo-ternary mixtures at several temperatures and compositions, since the knowledge of physical-chemical properties is essential for the formulation of a mixture fuel with characteristics within specifications. Experimental data density and viscosity were adjusted through regression models for determining the behavior as a function of temperature and composition and obtained a maximum standard deviation of 0.0087 and 0.1962, respectively, both for the system of methylic soybean biodiesel + methanol. Density and viscosity showed linear and exponential behavior, respectively, with temperature. As expected, an increase in temperature decrease density and viscosity for all systems studied. Since it is not feasible to obtain experimentally density and viscosity data in all conditions of interest, methods for their prediction are of great practical interest and were used in this work. In addition to obtaining the experimental data of density and viscosity also were realized physics stability tests and flash point for pseudo-ternary mixtures. It was observed that the physics stability has been influenced mainly by the temperature and alcohol content and to blends of alcohol + biodiesel + diesel the flash point is mainly dominated by the alcohol concentration.
A redução das emissões nos motores a diesel é estudada por muitos autores e a modificação da composição do combustível é uma das alternativas mais abordadas. Neste contexto, o estudo da mistura ab-diesel (álcool + biodiesel + diesel) tem atraído atenção devido algumas de suas características, tais como, calor de combustão semelhante ao do diesel “puro” e redução da emissão de material particulado e gases tóxicos. O óleo diesel é definido como um combustível derivado do petróleo, constituído basicamente por hidrocarbonetos e em baixas concentrações por compostos sulfurados, nitrogenados e oxigenados. A presença dos compostos parafínicos na composição do diesel dificulta a solubilidade de compostos polares, como os álcoois, dessa forma o biodiesel foi estudado como um agente capaz de solubilizar o álcool no diesel garantindo a formulação de misturas mais estáveis. A inserção desse combustível derivado de biomassa renovável constituído por uma mistura de mono-alquil ésteres de ácidos graxos de origem vegetal, animal e óleos residuais contribui também para a melhora de algumas outras características físico-químicas importantes na utilização dessa mistura como fonte de energia. A solubilidade dos sistemas pseudoternários constituídos de diesel + biodiesel metílico de soja + metanol e diesel + biodiesel etílico de soja + etanol foi estudada através da construção de curvas de equilíbrio líquido-líquido para duas temperaturas e observou-se que aumento da temperatura favoreceu a solubilidade dos componentes nos dois sistemas, contribuindo para formação de uma maior região homogênea. Assim como já era esperado, o sistema contendo etanol apresentou uma região homogênea bem maior que o sistema com metanol, uma vez que a solubilidade do primeiro no diesel é maior. As linhas de amarração não foram bem representadas pelos modelos termodinâmicos NRTL e UNIQUAC. Dados de densidade e viscosidade foram determinados para os componentes puros/pseudopuros e para misturas pseudobinárias e pseudoternárias em várias temperaturas e composições, uma vez que o conhecimento dessas propriedades físico-químicas é essencial para a formulação de uma mistura combustível com características dentro das especificações. Os dados experimentais de densidade e viscosidade foram ajustados através de modelos de regressão para determinação do seu comportamento em função da temperatura e composição e obteve-se um desvio padrão máximo de 0,0087 e 0,1962, respectivamente, ambos para o sistema de biodiesel metílico de soja + metanol. Densidade e viscosidade apresentaram comportamento linear e exponencial, respectivamente, com a temperatura. Como esperado, um aumento na temperatura diminuiu os valores de densidade e viscosidade para todos os sistemas estudados. Uma vez que não é factível obter experimentalmente dados de densidade e viscosidade em todas as condições de interesse, métodos para sua predição/estimação são de grande interesse prático e foram utilizados no presente trabalho. Além da obtenção dos dados experimentais de densidade e viscosidade, foram realizados também, ensaios de estabilidade física de fases e ponto de fulgor para as misturas pseudoternárias. Observou-se que a estabilidade física foi influenciada principalmente pela temperatura e teor de álcool e que para misturas do tipo álcool + biodiesel + diesel o ponto de fulgor é dominado principalmente pela concentração do álcool.
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Amandus, Nicholas P. "Locomotive emissions effects due to engine configuration." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3072.
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Thesis (M.S.)--West Virginia University, 2003.Title from document title page. Document formatted into pages; contains xiii, 164 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-87).
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Hernandes, Marcelo Rocha. "Estudo dos componentes auxiliares de partida a frio de motores movidos a Diesel." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264377.
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Orientador: Sergio Santos MühlenDissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A questão da partida a frio de motores movidos a Diesel ainda é um problema que não foi apropriadamente resolvido e se torna particularmente crítico em face da tendência de redução de níveis de emissões de poluentes a baixas temperaturas e da taxa de compressão do motor visando redução do consumo de combustível. Embora esteja claro que existem alguns fatores-chave que levam a um apropriado processo de partida a frio, sua relevância e relações não são claramente compreendidas. Assim, os esforços para a otimização do processo de partida a frio são principalmente baseados em procedimentos de tentativa e erro em câmaras climáticas a baixas temperaturas, com sérias limitações em termos de confiabilidade da medição em algumas condições, baixa repetibilidade e altos custos com experimentos. O objetivo deste trabalho é estudar os componentes auxiliares de partida a frio dos motores a Diesel com o intuito de adquirir conhecimento sobre este tema para aplicação em propulsores, de maneira que estes possam ser utilizados em regiões com temperaturas negativas com desempenho confiável. Os componentes estudados serão apresentados, bem como sua aplicação e importância na tarefa de proporcionar as condições adequadas à partida a frio do motor. Além disso, uma visão geral será dada em relação à contribuição que estes componentes trazem na redução de emissões de poluentes e consumo de combustível
Abstract: Cold start in Diesel engines is a problem which has not yet been properly solved and becomes particularly critical with the current trend to reduce the emission levels at low temperatures and engine compression ratio addressed to fuel consumption decrease. Although it is clear that there are some key factors whose control leads to a proper cold start process, their individual relevance and relations are not clearly understood. Thereby, the efforts on optimization of the cold start process are mainly based on a trial-and-error procedure in climatic chambers at low ambient temperature, with serious limitations in terms of measurement reliability, low repeatability and high experiments costs. The objective of this work is to study cold start auxiliary components of Diesel engines in order to acquire knowledge on this topic for application in engines in a way that they can be used in regions with low temperatures with reliable performance. The components studied will be presented, as well as its application and importance of providing appropriate conditions to engine cold start. In addition, an overview will be given on the contribution that these components are going to bring in the reduction of emissions and fuel consumption
Mestrado
Eletrônica
Mestre em Engenharia Automobilistica
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Collura, Salvatore Weber Jean-Victor Zambre Bruno. "Réactivité des suies diesel en atmosphères oxydantes." Metz : Université Metz, 2008. ftp://ftp.scd.univ-metz.fr/pub/Theses/2004/Collura.Salvatore.SMZ0410.pdf.
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Thormann, Janina. "Diesel-Dampfreformierung in Mikrostrukturreaktoren." Karlsruhe : Forschungszentrum Karlsruhe, 2009. http://d-nb.info/99396785X/34.
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Alfieri, Ezio. "Emissions-controlled diesel engine /." Zürich : ETH, 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18214.
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Tan, Yiping. "Automotive diesel turbocharger investigation." Thesis, University of Bath, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437605.
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Thormann, Janina. "Diesel-Dampfreformierung in Mikrostrukturreaktoren." Karlsruhe Forschungszentrum Karlsruhe, 2008. http://d-nb.info/994365071/34.
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Ebert, Tim. "Stille Gesellschaft, Genussrecht und partiarisches Darlehen als mezzanine Kapitaltitel zur Finanzierung einer GmbH : eine Analyse der historischen Entwicklung und Abgrenzung dieser Finanzierungsinstrumente sowie der mit diesen verbundenen Kompetenz- und Eigenkapitalersatzfragen im GmbH-Recht /." Frankfurt am Main [u.a.] : Lang, 2010. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=018920215&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Schönfuß-Krause, Renate. "Weihnachten und das Westpaket - diesen Duft konnte keine Grenze aufhalten." Teamwork Schönfuß, 2021. https://slub.qucosa.de/id/qucosa%3A75191.
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Die Erinnerung an „Westpakete“, die jahrzehntelang für viele Menschen die fast einzige Kommunikation über Grenzen hinweg zwischen West- und Ostdeutschland ermöglichten, haben sich tief in unser kollektives Gedächtnis eingeprägt. Mit diesen, besonders in der Weihnachtszeit erhaltenen Liebesgaben, verbinden sich bei vielen heute noch angenehmste Erinnerungen. Dabei hat sich etwas besonders tief eingeprägt und lebt in den Erzählungen weiter: Der einst so unvergleichliche Duft der Westpakete…
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Diesse, Marc [Verfasser]. "On Local Algebraic Geometry and Applications to Kinematics / Marc Diesse." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1216104964/34.
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Tompkins, Brandon T. "Emissions comparison between petroleum diesel and biodiesel in a medium-duty diesel engine." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2350.
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Hu, Jianrong. "Experimental studies of diesel combustion and emission in an optically-accessed diesel engine." Thesis, Brunel University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266649.
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Hanaki, Yasunari, and Kazuhiro Yamamoto. "Microfluidic Simulation of Diesel Exhaust Gas and Soot Oxidation in Diesel Particulate Filter." SAE International, 2013. http://hdl.handle.net/2237/20341.
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FILHO, FERNANDO FERRARI. "EVALUATION OF DIESEL CYCLE ENGINE OPERATING IN THE DUAL FUEL MODE: DIESEL / ETHANOL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19636@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROEste trabalho avaliou o comportamento de um motor do ciclo Diesel, operando no modo original (Diesel puro) e no modo bicombustível (Diesel / etanol), em dois modos de hidratação do álcool (70 e 93 graus INPM). A rotação foi mantida fixa em 1800 rpm. A finalidade foi estudar os parâmetros de desempenho do motor e analisar a liberação de calor pela combustão, como também, o calor trocado com as paredes. Avaliou-se como parâmetros de desempenho, o rendimento térmico, consumo específico de combustível e emissão de poluentes. A fase inicial do trabalho constou de ensaios experimentais realizados no conjunto motor / dinamômetro nos modos mencionados acima. O objetivo foi coletar a variação de pressão no interior do cilindro, consumo de combustível, emissão de gases, temperaturas em pontos estratégicos, entre outros. Em uma segunda etapa foi realizada uma análise dos parâmetros de desempenho e da liberação de calor. Para emissões de poluentes, observou-se uma diminuição de MP em altas taxas de substituição. No entanto, notou-se um aumento elevado de HC. Em baixas cargas e taxas de substituição elevadas houve redução de emissão de NOx. O rendimento térmico apresentou comportamentos similares em 70 e 93 graus INPM. Em altas cargas e altas taxas de substituição houve um sensível aumento do rendimento quando comparado ao modo original. O rendimento foi menor para baixas cargas com altas taxas de substituição, em relação ao modo original. O início da combustão no modo bicombustível foi antecipado em relação ao modo original, nas condições de altas cargas e máximas taxas de substituição. Isto foi devido à liberação de calor que ocorreu mais cedo no modo bicombustível. Ressalta-se que, nas mesmas condições, houve a ocorrência de um maior calor trocado com as paredes do cilindro, em ambos os modos de hidratação (70 – 93 graus INPM), quando comparado ao modo original.
This work aimed to evaluate a Diesel cycle engine operating in the original (only Diesel) and dual-fuel modes (Diesel / ethanol) in two levels of hydration of alcohol (70 and 93 degrees INPM). Speed was kept fixed at 1800 rpm. The purpose was to study the parameters of engine performance and analyze the heat release by combustion and heat exchanged to the cylinder’s walls. For parameters of performance, evaluation of thermal efficiency, specific fuel consumption and emissions were conducted. Initial activities consisted in trial tests on the engine / dynamometer in the two modes as mentioned above. The goal was to collect the variation of indicated cylinder pressure data, as well as fuel consumption, emissions and temperatures at strategic points. Secondly, performance parameters and heat release analysis was performed. For emissions, a decrease in PM was found at higher replacement rates; however, in the same condition a large increase in HC was obtained. At low loads and at higher replacement rates, NOx emissions were reduced. Thermal efficiency showed similar behavior at 70 and 93 degrees INPM. At high loads and at higher replacement rates a significant increase in thermal efficiency compared to the original mode and for low loads with higher replacement rates thermal efficiency was decreased. In high loads and at higher replacement rates conditions, the process of combustion occurred before in the dual fuel mode, due to earlier heat release compared to original mode (only Diesel). In the same conditions an increase of heat exchanged to the cylinder’s wall in both modes of hydration of alcohol (70 and 93 degrees INPM) compared to the original mode was obtained.
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Júnior, Roberto Freitas Britto. "Experimental analysis of a diesel engine operating in diesel-ethanol dual-fuel mode." Instituto Tecnológico de Aeronáutica, 2014. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3043.
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A significant part of the world economy depends on stationary or vehicular Diesel engines. Such engines are fed mainly by fossil fuels, among these, the standard diesel. The growing interest in renewable energy sources makes the use of ethanol in these engines a real technological demand. From the existing concepts to meet this goal the Diesel-Ethanol in the Dual-Fuel mode has demand for published experimental data. Such concept brings a greater degree of freedom, but implications in technological challenges. It works through a PFI (Port Fuel Injection) system to prepare a pre-mixture of air and ethanol in the intake port which is compressed in the combustion chamber and ignited by pilot injection of diesel. In this work a single cylinder research engine with 100% electronically controlled calibration was used. The engine control parameters were set to maximize diesel substitution rate by ethanol with a limited indicated efficiency loss. Comparisons were made among different working conditions. Initially, the flow structure in the combustion chamber was tested in both quiescent and high swirl modes. Compression ratios were adjusted at 3 different levels: 14:1, 16:1 and 17:1. Two injectors were tested, the first one with mass flow of 35 g/s and another of 45 g/s. Regarding pressure diesel injection, 4 levels were investigated namely 800, 1000, 1200 and 1400 bar. The experiments discussed in this work were able to achieve up to 65% of diesel energy substituted by hydrated ethanol energy with an indicated efficiency of 49%. In comparison with the diesel only running condition, the NOx emissions was improved by up to 60%. But the HC, CO and aldehydes emissions had a penalty, showing a trade-off that shall be further investigated with a final design engine in the beginning of product development process.
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Andrade, Rômulo Davi Albuquerque. "Calor de combustão de Blendas do tipo diesel/biodiesel e diesel/bio-óleo." reponame:Repositório Institucional da UnB, 2009. http://repositorio.unb.br/handle/10482/4960.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, 2009.Submitted by Allan Wanick Motta (allan_wanick@hotmail.com) on 2010-05-31T17:37:34Z No. of bitstreams: 1 dissertacao romulo.pdf: 1361167 bytes, checksum: 8c6656e1955de8c9825ecbacd9cb89fb (MD5)
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O programa brasileiro de biocombustíveis prevê a adição de 2% de biocombustíveis em diesel até 2008 e 5% até 2013. Assim, o estudo do calor de combustão das blendas biocombustível/diesel é um gargalo tecnológico que necessita ser solucionado. O biodiesel foi obtido a partir da reação de transesterificação de óleo de soja, com um rendimento de 87% o bio-óleo foi obtido pelo craqueamento térmico do óleo de soja e tiveram a maioria os parâmetros de acordo com as normas da ANP. Os resultados calorimétricos mostraram que os valores de calor de combustão foram 41,36 ± 0,17; 38,70 ± 0,16; e 36,71 ± 0,17 MJ/kg para o diesel, bio-óleo e biodiesel, respectivamente. Os resultados mostraram que o calor de combustão dos biocombustíveis são aproximadamente 17 % inferiores aos valores do calor de combustão do diesel de petróleo. Mais ainda, os dados mostraram que os valores de calor de combustão dos biocombustíveis dependem do método de produção do biocombustível. Os valores de calor de combustão das blendas biocombustível/diesel fóssil diminui linearmente com a adição do biocombustível nas blendas. Os valores do calor de combustão encontrados na amostra B5 mostraram resultados muito semelhantes com os valores do calor de combustão do diesel de petróleo, justificando seu uso de acordo com a lei n° 11.097/2005 que determina a adição de 5% de biodiesel no diesel de petróleo. __________________________________________________________________________________________ ABSTRACT
The Brazilian government has also present biofuel program, which it has the main to add 2 % of biofuel in fossil diesel in 2008 and 5 % up to 2013. Thus, the knowledge of heat of combustion of biofuel/diesel blends is necessary. The biodiesel was produced by transesterification of soybean oil with yield of 87%. The diesel-like was obtained by pyrolysis of soybean oil; this biofuel presented all parameters in according to ANP. The obtained heats of combustion were 41.36 ± 0.17; 38.70 ± 0.16; e 36.71 ± 0.17 MJ/kg for diesel, diesel-like and biodiesel, respectively. The results show the heats of combustion of biofuels are approximately 17 % smaller than fossil diesel. The data also show the heats of combustion depend on the methodology used for the biofuel production. Addition of biofuels to traditional diesel fuel results in a linear decreasing of the heat of combustion with the amount of the alternative fuel added to the diesel.
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Hassan, Mohamad. "Conversion en diesel-gaz d'un moteur diesel à injection directe de faible puissance." Valenciennes, 1992. https://ged.uphf.fr/nuxeo/site/esupversions/be2998f3-db38-4ee2-a7bd-e9ed853663aa.
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Nous étudions le problème de la conversion en diesel-gaz naturel d'un moteur diesel standard à injection directe de 55 kw et l'influence des principaux paramètres de fonctionnement. Les limites imposées pour les charges thermiques et les contraintes mécaniques sont celles du diesel. Il faut refroidir les injecteurs pour éviter leur grippage et pouvoir effectuer à tout moment la commutation diesel-gaz-diesel. Le taux d'injection pilote minimum acceptable pour un fonctionnement stable du moteur qui est de 7% avec les injecteurs d'origine peut être ramené à 2,5% avec des injecteurs monotrous.
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Bertacchi, D., and Andreas Cap@esi ac at. "Random Walks on Diestel--Leader Graphs." ESI preprints, 2001. ftp://ftp.esi.ac.at/pub/Preprints/esi1004.ps.
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Tirel, Emmanuel. "Zinc complexes for phosphate diester hydrolysis." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/7788/.
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This work focuses on catalysing the hydrolysis of DNA-like substrate with mononuclear zinc complexes. Particular attention is given to find new ways of activating the nucleophile of the reaction and to study the impact of organic groups that affect the microenvironment of the metal ion.
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Park, Talus. "Dual fuel conversion of a direct injection diesel engine." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=460.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains x, 96 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).
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Squaiella, Lucas Lázaro Ferreira. "Efeitos do sistema de recirculação dos gases de escape no controle de emissões de NOx em motores a diesel." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263698.
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Orientadores: Cristiane Aparecida Martins, Pedro Teixeira LacavaDissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Veículos automotores são responsáveis pela maior parte da locomoção no mundo moderno. A principal forma de energia propulsora utilizada baseia-se na queima de combustíveis fósseis. Em sistemas reais de combustão o processo químico envolvido apresenta alto grau de complexidade que se traduz, na emissão de cinco principais espécies de poluentes atmosféricos, a saber, monóxido de carbono, compostos orgânicos (hidrocarbonetos não queimados ou apenas parcialmente queimados), particulados, óxidos sulfurosos e óxidos nitrogenados. Graças a crescente e necessária preocupação ambiental as normas relativas a emissões têm sido periodicamente revistas, sendo uma das principais o Padrão Europeu definido como Euro que disciplina veículos que circulam na Europa e demais países que como o Brasil que a adotam como modelo. Motores a diesel têm como emissão crítica os óxidos nitrogenados, NOx (NO + NO2) e as emissões de material particulado. As diferentes técnicas utilizadas para reduzir a formação destes poluentes podem ser divididas entre aquelas aplicadas durante o processo de combustão e as outras aplicadas somente após a combustão, ou seja, nos gases de exaustão. O presente trabalho utilizou-se de uma técnica que atua no processo de combustão conhecida como EGR, Recirculação Parcial dos Gases de Exaustão. O objeto de estudo é um motor diesel de quatro cilindros em linha, equipado com EGR que atende a Euro III, com limite de NOx igual a 5,0 g/kWh. A premissa do trabalho é a avaliação do potencial deste motor em atingir os níveis de emissões da norma Euro VI, com limite de NOx igual a 0,4 g/kWh. Para tal, serão mantidas as configurações originais do motor, alterando-se somente os componentes que fazem parte do sistema de EGR. O estudo foi realizado em diferentes etapas, I, II e III, durante as quais foram identificados os componentes de EGR que mais influenciam para a redução do NOx. Os resultados obtidos são satisfatórios, alcançando valores próximos ao objetivo, mostrando desta forma que o estudo é de grande aplicabilidade para os motores atuais e futuros
Abstract: Automotive vehicles are responsible for the most of locomotion in the modern world. The mainly propulsive energy used is based on burning of fossil fuels. In real combustion systems the chemical process involved a high complexity which results mainly in five types of air pollutants, that are, carbon monoxide, organic compounds as hydrocarbons unburned or partially burned, ashes, oxides sulfur and nitrogen oxides. Due to growing of necessity to care the environment concern, emissions standards have been reviewed periodically and one of the main is European Standard defined as Euro that discipline European vehicles and other countries like Brazil that concern it as a model. The most critical diesel engine emission are nitrogen oxides, NOx (NO + NO2) and particulate matter. The different techniques used to reduce the formation of these pollutants can be divided into those applied during the combustion process and other applied only after combustion, in the exhaust gases. This study used a technique that operates in the combustion process known as EGR, Exhaust Gas Recirculation. The object of study is a fourcylinder diesel engine, in line, equipped with EGR that meets the ,Euro III emission standards with NOx limit as 5,0 g / kWh. The premise work was evaluated the potential of this engine to achieve the Euro VI emission levels, with NOx limit as 0,4 g / kWh. To do this the original basic engine parts will be kept, to changing only the components that are part of the EGR system. The study was conducted at different stages I, II and III, to identify which EGR components have more influence to reduce NOx. The results are consider satisfactory, reaching values close to the goal, thus demonstrating that the study is of great applicability to current and future engines
Mestrado
Motores
Mestre em Engenharia Automobilistica
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Wei, Fang. "A study on the improvement of marine diesel engine transient performance by means of air injection." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B36834841.
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Leite, Danilo. "Desempenho e emissões de motor gerador operando com blendas de diesel/óleo de soja, diesel/óleo de linhaça e diesel/óleo de crambe." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3779.
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In Brazil, rural communities away from the big centers, away from transmission and distribution electric grid, doesn´t have electric power hindering local economic progress. So, an alternative to a solution of the problem is a source of energy through fuels a base of vegetable oil, local raw material, renewable and of less environmental impact, justifying this work. The production service and the performance and emissions of a diesel generator set operating with fuels a vegetable oil base of soybean, linseed and crambe. The fuels were tested from a 5kVA generator set, without mechanical adaptation and connected to a electrical charges bank manufactured to dissipate the generated electric energy. Biofuels were obtained from the mixture of conventional diesel oil with soybean oil, linseed and crambe at incremental levels of 10%, 30%, 50% and 70% of vegetable oil in the composition of the fuel mixture and submitted to physicochemical viscosity analysis and density. In the evaluation of the performance of the generator was measured voltage (V), electric current (A), frequency of electric current (Hz), electrical power (W), wight (g), generator set noise (dB) and measured the exhaust gas concentration. The results of the studies show us that mixtures of conventional diesel (B8) with vegetable oil of soybean, linseed and crambe, in concentrations of up to 30%, presented with an effective technical alternative for a partial replacement of conventional diesel in the production of electric power, with reduction in emission levels and maintenance of the performance of the generator set.
No Brasil, comunidades rurais afastadas dos grandes centros, distantes das redes de transmissão e distribuição de energia, carecem de energia elétrica dificultando o progresso econômico local. Assim, uma alternativa para a solução do problema é a própria geração de energia através de combustíveis a base de óleo vegetal, matéria prima local, renovável e de menor impacto ambiental, justificando este trabalho. Avaliou-se o desempenho e emissões de um conjunto motor gerador diesel operando com combustíveis a base de óleo vegetal de soja, linhaça e crambe. Os combustíveis foram ensaiados a partir de um conjunto motor gerador de 5kVA, sem adaptação mecânica e ligado a um banco de cargas resistivas fabricado para dissipação da energia elétrica gerada. Os biocombustíveis foram obtidos da mistura do óleo diesel convencional com óleo de soja, linhaça e crambe em níveis incrementais de 10%, 30%, 50% e 70% de óleo vegetal na composição da mistura combustível e submetidos a análise físico-química de viscosidade e densidade. Na avaliação de desempenho do conjunto motor gerador foram realizadas medições de tensão (V), corrente elétrica (A), frequência da corrente elétrica (Hz), potência elétrica (W), consumo mássico (g), ruído do conjunto motor gerador (dB) e realizado a medição da concentração dos gases de exaustão. Os resultados dos estudos realizados apontam que misturas do diesel convencional (B8) com óleo vegetal de soja, linhaça e crambe, em concentrações de até 30%, apresentam-se como uma alternativa técnica eficaz na substituição parcial do diesel convencional na produção de energia elétrica, com redução nos níveis de emissões e manutenção de desempenho do conjunto motor gerador.
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Dovifaaz, Xavier. "Modélisation et commande d'un moteur Diesel en vue de la réduction de ses émissions." Amiens, 2001. http://www.theses.fr/2001AMIE0003.
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Batista, Matheus Maciel 1980. "Determinação dos parâmetros de solubilidade de óleos vegetais, biodieseis, diesel e blendas biodiesel-diesel." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266089.
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Orientador: Maria Alvina KrähenbühlTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: A busca por combustíveis alternativos vem ganhando destaque nas últimas décadas. A substituição de combustíveis fósseis tem sido impulsionada por fatores ambientais, econômicos e sociais, uma vez que toda a sociedade depende de seu uso. Neste contexto, uma alternativa que tem se destacado é o do biodiesel. O biodiesel representa uma alternativa renovável, biodegradável, não inflamável e de baixa toxicidade para o diesel. Os parâmetros de solubilidade tridimensional definidos por Hansen são baseados em forças de dispersão entre as unidades estruturais, interações entre os grupos polares e de ligação de hidrogênio. Estes parâmetros de solubilidade são propriedades importantes de várias substâncias e ferramentas muito úteis para a seleção de seus solventes ou a previsão de seu comportamento em diferentes aplicações. A sua concepção e avaliação baseia-se na regra básica de "similaridade" para solubilidade. Neste trabalho foram determinados os parâmetros de solubilidade de Hansen (?D, ?P e ?H) e raio da esfera de solubilidade do soluto (R0) para os óleos de soja, fritura, palma, coco e mamona; para os biodieseis provenientes desses óleos, diesel e blendas biodiesel-diesel (B10 e B20), usando 45 solventes e misturas de solventes. Os valores dos parâmetros de solubilidade obtidos para os óleos de soja e fritura foram idênticos e similares àqueles obtidos para os óleos de coco e palma. O óleo de mamona apresentou maiores valores ?P e ?H, devido à presença de uma hidroxila em sua estrutura carbônica. O mesmo comportamento foi observado para os biodieseis, ou seja, biodieseis de soja e fritura, com parâmetros de solubilidade idênticos, e similares aos biodieseis de palma e coco; o biodiesel de mamona exibindo valores de ?P e ?H mais elevados entre os biocombustíveis produzidos. Os parâmetros de solubilidade de Hansen de quatro biocombustíveis (soja, palma, coco e mamona) foram obtidos a partir dos valores da média dos parâmetros de solubilidade dos ésteres graxos metílicos, proveniente de cada óleo vegetal, utilizando os métodos de contribuição de grupos. Posteriormente, as solubilidades dos biocombustíveis foram preditas usando abordagens de van Krevelen, Greenhalgh e Bagley. O óleo diesel apresentou menores valores de ?D, ?P e ?H se comparado com os valores obtidos para os biodieseis. Os valores dos parâmetros de solubilidade do diesel, B10 e B20 foram semelhantes, aumentando os valores de acordo com a quantidade (em volume) de biodiesel adicionado ao combustível diesel
Abstract: The search for alternative fuels has been gaining attention in recent decades. The replacement of fossil fuels has been driven by environmental, economic and social factors, since the whole of society is dependent on their usage. In this context, one alternative that has been highlighted is that of biodiesel. Biodiesel represents a renewable, biodegradable, non-inflammable and low toxicity alternative to diesel. The three dimensional solubility parameters defined by Hansen are based on dispersion forces between structural units, interaction between polar groups and hydrogen bonding. These solubility parameters are important properties of the various substances and very useful tools in the selection of their solvents or the prediction of their behavior in different applications. Their design and evaluation are based on the basic rule of "similarity" for solubility. In this work the Hansen solubility parameters (?D, ?P and ?H) and the radii of the solubility spheres of the solutes (R0) were determined for soybean, frying, palm, coconut and castor oils, for the biodiesels obtained from these oils and diesel and the biodiesel-diesel blends (B10 and B20), using 45 solvents and solvent mixtures. The values obtained for the solubility parameters of the soybean and frying oils were identical and similar to those obtained for the coconut and palm oils. Castor oil showed higher ?P and ?H values due to the presence of a hydroxyl in its carbon structure. The same behavior was observed for the biodiesels, i.e. identical solubility parameters for the soybean and frying biodiesels which were similar to the palm and coconut biodiesels, the castor biodiesel showing the highest values for ?P and ?H of the biofuels produced. The Hansen solubility parameters for four biofuels (soybean, palm, coconut and castor) were obtained from the values of the average solubility parameter for the fatty acid methyl esters derived from any vegetable oil, using the group contribution methods. Subsequently, the values for the solubility of the biofuels were predicted using the van Krevelen, Greenhalgh, and Bagley approaches. Diesel presented lower values for ?D, ?P and ?H when compared to the values obtained for the biodiesels. The values of the solubility parameters of diesel, B10 and B20 were similar, the values increasing according to the amount (by volume) of biodiesel added to the diesel fuel
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química
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Brunale, Patrícia Portela de Medeiros. "Identificação molecular de micro-organismos cultiváveis contaminantes de Diesel A e Diesel B s500." reponame:Repositório Institucional da UnB, 2017. http://repositorio.unb.br/handle/10482/23521.
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Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Tecnologias Química e Biológica, 2017.Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2017-05-12T20:35:03Z No. of bitstreams: 1 2017_PatríciaPorteladeMedeirosBrunale.pdf: 2286800 bytes, checksum: e9fab1a536ad697ef8cd47ef54b81a75 (MD5)
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Com a crescente demanda mundial de combustíveis e materiais oriundos do petróleo, são necessárias alternativas sustentáveis a fim de minimizar o impacto ambiental. Assim sendo, o biodiesel é uma alternativa para substituição do óleo de diesel fóssil. Biofilmes microbianos são formados nas interfaces óleo/água em tanques de armazenamento contendo a mistura de biodiesel e diesel, diminuindo a qualidade dos combustíveis, o que leva a perdas econômicas e ambientais, pois a combustão não eficiente acarreta na perda de potencia do veiculo e pode aumentar a emissão de gases do efeito estufa (BÜCKER et al., 2014). A contaminação microbiana de combustível pode ocorrer em vários pontos do sistema de distribuição deste, mas é particularmente evidente durante a armazenagem, especialmente se há água livre no reservatório (BÜCKER et al., 2014). É fundamental conhecer os principais contaminantes desses combustíveis para que sejam propostas medidas que possam aliviar esse problema. Atualmente, o monitoramento da qualidade é feito apenas na usina e nos postos de combustiveis. Portanto, a contaminação destes combustiveis pode ocorrer durante o transporte e/ou armazenamento, que é um problema a ser estudado. Neste trabalho, amostras de diesel S 500 foram obtidas em uma distribuidora e uma amostra de diesel S500 + B7 no posto de gasolina. As amostras foram acondicionadas em frascos e transportadas para o laboratório onde foram armazenadas em tanques de 10L para realização do estudo microbiano em condições que mimetizam o armazenamento nos postos de combustiveis. Para a determinação da dinâmica populacional das comunidades microbianas contaminantes por técnicas dependentes de cultivo, as amostras armazenadas em tanque por diferentes tempos foram filtradas e os microrganismos isolados pelo método de isolamento total de bactérias, leveduras e fungos filamentosos. Após cultivo, os microrganismos foram purificados e armazenados, formando um banco de microrganismos contaminantes dos combustíveis. A identificação destes microrganismos foi realizada por abordagem polifásica, baseada na sequencias de genes codificadores de RNA ribossomal (rDNA). Foram encontradas as seguintes espécies prováveis de bactérias: Paenibacillus taichungensis (T), Lysinibacillus macroides (T), Bacillus subtilis, Bacillus safensis, Bacillus toyonensis (T), Bacillus pumilus, Bacillus cereus, Janibacter melonis (T), Bacillus anthracis (T), Bacillus amyloliquefaciens (T), Bacillus tequilensis (T) e Bacillus licheniformis (T). E, foram encontrados os gêneros de fungos: Paecilomyces, Byssochlamys e Aspergillus e as prováveis espécies de Aspergillus fumigatus e tamarii.
Given the growing world demand for fuels and materials derived from petroleum which cause great environmental impact, renewable and more environmentaly friendly alternatives are needed. Therefore, biodiesel is a substitute alternative for fossil diesel oil. Microbial biofilms are formed at the oil / water interfaces in storage tanks containing the blend of biodiesel and diesel, reducing fuel quality and increasing economic and environmental losses, because inefficient combustion can causes loss of vehicle power and can increase greenhouse gas emissions (BÜCKER et al., 2014). Microbial fuel contamination can occur at various points in the fuel distribution system, but is particularly evident during storage, especially if there is free water in the reservoir (BÜCKER et al., 2014). It is essential to identify the main microbial contaminants of this biofuel so that effective measures can proposed to alleviate this problem. Currently, this fuel quality is monitored only at the distributor plant and in the fuel stations. Therefore, contamination of this fuel during transportation and storage is a problem that needs to be studied. The S 500 Diesel samples were obtained from the distributor and the S500 + B7 diesel samples were obtained at a gas station. The samples were transported to the lab in flasks, and then stored in 10L tanks that mimicked storage conditions in the gas station to perform the study of microbial contaminants. For the determination of the population dynamics of microbial communities by culture-dependent techniques, the samples from fuel stored for different legths of time were filtered and bacteria, yeasts and filamentous fungi were isolated. After culturing, the microorganisms obtained were purified and stored, forming a bank of microbial contaminants found in fuel. The identification of microoraganisms was performed using a polyphasic approach, based on sequences for ribosomal RNA genes and biochemical. The probable species of bacteria that were found: Paenibacillus taichungensis (T), Lysinibacillus macroides (T), Bacillus subtilis, Bacillus safensis, Bacillus toyonensis (T), Bacillus pumilus, Bacillus cereus, Janibacter melonis (T), Bacillus anthracis (T), Bacillus amyloliquefaciens (T), Bacillus tequilensis (T) e Bacillus licheniformis (T). And, the probable genera of fungi that were found: Paecilomyces, Byssochlamys e Aspergillus, and probables species are Aspergillus fumigates e tamarii.
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Kaminuza, Irénée. "Thermal and chemical analysis of carbonaceous materials: diesel soot and diesel fuel reactor deposits." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/16911.
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Methods for the characterisation of fuel-derived carbonaceous materials were assessed. These methods were applied to two such materials, viz. diesel soot and diesel fuel deposits. Diesel soot: Diesel soot, sampled from a commuter bus, was characterised using an array of analytical techniques. Physical and chemical characterisation of diesel soot was conducted with particular interest in the component of soot known as the soluble organic fraction (SOF). The SOF represents adsorbed chemical species and is traditionally obtained via Soxhlet extraction of soot using an organic solvent. Chemical speciation of the SOF was performed using GC-MS analysis. Five solvents (hexane, cyclohexane, toluene, methanol and acetone) were compared with dichloromethane, the most extensively used solvent for the extraction of soot with respect to their ability to extract a variety of species, including polyaromatic hydrocarbons (PAHs) and potential endocrine disrupting molecules, e.g. phthalates. Extraction results suggest that the SOF quantity depends significantly on the extraction solvent. For the soots analysed, SOF ranged between 1.0 and 4. 8 wt %, depending on the solvent used. Moreover, it was shown that polar solvents extracted a greater SOF than non- polar solvents. For PAH extraction the order of efficiency was acetone > methanol > > toluene > hexane > cyclohexane while for esters, including endocrine disrupting phthalates, the order in efficiency was methanol > dichloromethane >acetone > toluene > > hexane > cyclohexane > n-hexane. A suggestion is made that to maximise SOF, sequential extraction should be made. Thermogravimetric analysis revealed a discrepancy between VOF and SOF which was ascribed to the presence of sulfurous and sulfuric acid which were not extracted by the organic solvents investigated Fuel deposits: Fuel was degraded in three reaction vessels, viz. a continuous flow reactor, open glass flask s and closed metal reactors (bombs) in an attempt to synthesise carbonaceous deposits, analogous to those found in diesel injectors. The degradation of four diesel fuels, viz. an EN590 reference diesel, a commercial diesel and two B20 biodiesel blends (rapeseed and soybean methyl esters blended with EN590 diesel), was investigated in the thermo-oxidative temperature regime, i.e. below 300° C.
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Bacha, Kenza. "Interaction entre les carburants diesel et biodiesel et les composants du système d'injection diesel." Thesis, Mulhouse, 2016. http://www.theses.fr/2016MULH4471.
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Le système d’injection Diesel doit résister à des conditions opératoires (pression, température) de plus en plus sévères, et être compatible avec les évolutions du carburant diesel, telles que l’introduction des Esters Méthyliques d’Acide Gras (EMAG) et l’utilisation de différents additifs, qui peuvent affecter la durabilité des véhicules, suite à la formation de dépôts. L’objectif des travaux de cette thèse est la compréhension des mécanismes de formation des dépôts issus de l’oxydation des carburants et la détermination des paramètres majeurs participant aux interactions dépôts-substrats (état de surface, matériaux, géométrie, thermique…). Deux études ont été abordées dans cette thèse. La première étude porte sur l’oxydation accélérée des carburants Diesel, des EMAG et des mélanges Diesel/EMAG en phase liquide en utilisant le moyen d’essai PetroOxy, la cinétique d’oxydation a été déterminée pour les différents carburants et la caractérisation des produits d’oxydation a été effectuée utilisant les moyens d’analyse (FTIR-ATR, ATG/DTG et GC/MS). La seconde étude est dédiée à la reproduction du dépôt sur les substrats en (aluminium, acier inoxydable, PEEK, revêtement or sur aluminium, revêtement silcoklean sur acier inoxydable) en utilisant le moyen d’essai Micro Cokage et la caractérisation du dépôt obtenu dans chaque cas en utilisant les moyens d’analyse (FTIR-ATR, ATG/DTG, FEG et XPS). Les résultats de ces travaux ont permis de déterminer l’impact de la nature et du taux d’EMAG ajouté au Diesel sur la stabilité à l’oxydation des carburants ; de mettre en place une hypothèse de formation de dépôt à partir de l’oxydation des carburants en phase liquide jusqu’à la formation de nanoparticules de dépôt sphériques ; et déterminer l’impact du substrat sur la formation et l’adhésion du dépôt à la surface du matériauDiesel injection system must withstand more severe operating conditions (pressure, temperature), and be compatible with the evolution of diesel fuel, such as the introduction of Fatty Acid Methyl Esters (FAME) and use of different additives, which may affect the durability of the vehicle, following the formation of deposits. The objective of this work is to understand the mechanisms of deposit formation from fuel oxidation and determine the major parameters involved in deposit-substrate interactions (surface condition, materials, geometry, temperature...). Two studies were discussed. The first study focuses on the liquid phase accelerated oxidation of Diesel fuel, FAME and mixtures (Diesel / FAME) using PetroOxy device, the oxidation kinetic was determined for the different fuels and characterization of oxidation products was carried out using the (FTIR-ATR, ATG / DTG and GC / MS). The second study was dedicated to the reproduction of deposit on different substrates (aluminum, stainless steel, PEEK, aluminum coating on gold, silcoklean coating on stainless steel) using the Micro Coking device, and characterization of the deposit obtained in each case using (FTIR-ATR, ATG / DTG, XPS and FEG). The results of this work permit to determine the impact of FAME nature and FAME concentration on fuel oxidation stability; an hypothesis was proposed to explain deposit formation
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Reifarth, Simon. "EGR-Systems for Diesel Engines." Licentiate thesis, KTH, Machine Design (Div.), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12205.
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Alshahrani, Farhan M. "Oxidative desulfurization of diesel fuels." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491293.
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This thesis describes the development of a simplified catalytic system for the deep removal of sulfur from hydrocarbon-based transportation fuel. The work is divided into four main parts, a literature review of different desulfurization technologies, oxidative desulfurization, the newly developed ODS process and its results, a quantitative and kinetic study of the ODS process. The principal aims of this research were to (i) explore and develop a new oxidative desulfurization process, (ii) measure the efficiency of the process on desulfurization of model solution representing hydrocarbon-based fuels, (iii) explore further the feasibility of applying the ODS process on a commercial diesel samples (iv) make comparison of the effect of the ODS process on different sulfur containing compounds (v) quantitative analysis of the biphasic system ~s a result of the oxidative desulfurization reaction and (vi) kinetic study of the ODS process to determine the reaction constants and activation energy at different reaction temperatures. This thesis is composed of six chapters as the following: CHAPTER l: The thesis commences with comprehensive introduction divided into two parts: Part I discusses the origin of petroleum and its hydrocarbon derivatives and describes the major components of crude oil and their refining processes. In addition, the hydrotreating process was given more attention since it has been for long the conventional hydrodesulfurizaion (HDS) unit in most refineries. Moreover, .the sulfur recovery after refining is also included. Part II describes the major oil contaminates with emphasis on the nature of sulfur compounds present and their removal. It also includes the different hydrotreating, e.g HDS, and non-hydrotreating routes for sulfur removal such as adsorption, photocatalysis, ultrasonic technique, ~ j1IIIIIII extraction, ionic liquids, biodesulfurization and oxidation. CHAPTER 2: With showing the pros and cons of using HDS for deep removal of sulfur compounds, this chapter covers a general overview of the catalytic oxidation desulfurization of transportation fuel. This chapter sheds some light on the history and development of the oxidative processes over the last sixty years or so. The main components of oxidative catalytic processes such as oxidizing agent, catalyst, phase transfer agent and solvents were also explained with mentioning previous publications in this regard. CHAPTER 3: This chapter is focusing comprehensively on the chemical materials and feedstock like diesel that was used in this research. This chapter describes step supervision of Prof. Malcolm L. H. Green, FRS. The experimental procedures covers the Inorganic Chemistry Laboratory of the University of Oxford under the by step the overall experimental procedures carried out over the last three years in· I I ___J III about pervious very relevant oxidative catalytic processes and the rational behind all the lab work carried out to develop a simplified ODS process for diesel. A section selecting the sodium tungstate system is also included. CHAPTER 4: As a result, this chapter explains the results of discovered ODS process compose of 30% hydrogen peroxide, sodium tungstate and acetic acid. The effects of the ODS catalytic system .on model solutions of selected sulfur compounds is also included in this chapter. The result of applying the ODS catalytic system on a commercial hydrotreated diesel obtained from Saudi Aramco is thoroughly explained .with supportive' analytical results from the ICL and the Royal Institute of Great Britain, RIGB. Comments on the mechanism of the ODS reaction is also included in this chapter. CHAPTER 5: After establishing the ODS catalytic system, an in depth study of the optimum material quantities and reaction conditions is included in this chapter. In fact, it starts with quantitative calculations of the two layers as a result of having a biphasic solution. A comprehensive kinetic study of the effect of ODS catalytic system on nine different sulfur containing compounds is also included in this chapter. The reaction rate constants and activation energy at different reaction temperature of the said sulfur compounds have also been explored. Based on their reaction rate, this concludes by shown the trend of desulfurization of the selected different sulfur compounds. CHAPTER 6: The aim of this chapter is to give a final comprehensive conclusion of tllis thesis, Based on the ODS bench scale discovery, this chapter proposed as well the necessity of taking this research further for scale up if possible.
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Nwafor, Onwuzurigbo Martin I. "Alternative fuels in diesel engines." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239031.
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Barr, William Gerald. "Low heat rejection diesel engines." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254429.
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Bari, Saiful. "Alternative fuels in diesel engine." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303788.
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Brito, Lopes Alisson Vinicius 1989. "Simulação fenomenológica de motores diesel." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265916.
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Orientador: Waldyr Luiz Ribeiro GalloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: Um modelo de simulação fenomenológico de motores Diesel foi desenvolvido. O modelo permite a simulação das fases aberta e fechada do ciclo. A combustão é modelada utilizando um modelo de liberação de energia finita. É levado em conta um modelo unidimensional para escoamento sobre as válvulas e um modelo para a transmissão de calor instantânea entre os gases e a parede do cilindro. Por se tratar de um modelo paramétrico, uma série de estudos pode ser feita no sentido de avaliar as influências dos diversos parâmetros sobre os valores finais de eficiência global do motor. As curvas características e as eficiências do motor correspondem aos resultados finais obtidos após o processo iterativo. Um motor é comparado quando simulado em duas situações: com e sem cruzamento de válvulas. Ao simular o caso base (sem cruzamento de válvulas) foi possível comparar a potência efetiva de eixo declarada pelo fabricante (49 kW) e constatar que a potência calculada pelo modelo foi de 51.3 kW indicando assim que as hipóteses adotadas foram bastante razoáveis. Além disso, o modelo forneceu valores para eficiência volumétrica, consumo específico e eficiência térmica condizentes com os valores usualmente encontrados nas referências bibliográficas. Constatou-se que ao gozar de um curto cruzamento de válvulas o motor teve seus parâmetros de eficiência aumentada em 3%, além de uma redução de 3.3% no consumo específico de combustível, valores esses quando comparados ao caso base. O algoritmo desenvolvido permitiu também analisar a influência do ponto de injeção na curva de pressão de combustão, a influência da rotação na curva de taxas mássicas na admissão/escape e a influência da quantidade de combustível injetada sobre as potências de atrito, efetiva e indicada
Abstract: A phenomenological simulation model of Diesel engine was developed. The model is able to simulate the open and closed phase of the cycle. The combustion process is modeled by using a finite heat release model. A one-dimensional model is applied for the flow through the valves and the instantaneous heat transfer between gases and cylinder wall. As the model is parameterized, a series of studies can be done to evaluate the influence of several parameters on the final values of the overall engine efficiency. Typical engine curves and the engine efficiencies are obtained as a result of the interactive process. An engine is compared when simulated in two situations: with and without valve overlapping. By simulating the baseline case (without valve overlapping) it was possible to compare the brake power informed by the engine manufacturer (49 kW) and that obtained by model was (51.3 kW), showing that the hypothesis adopted was reasonable. Furthermore, the model provides values for the volumetric efficiency, specific fuel consumption and thermal efficiency in agreement with values usually found in both the bibliographic references and manufacturer¿s data. It was found that when the engine operated with a short valve overlapping, the engine achieved 3% of improvement in the efficiency parameters and 3.3% of reduction in specific fuel consumption, these values are compared with the base case. The algorithm developed also allowed to analyze the influence of the injection start point in the combustion pressure curve, the influence of engine rotation in the mass rate in intake and exhaust process and the influence of equivalence ratio on the friction, effective and indicated power
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica
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Fitz, Leonardo. "A obra de Eladio Dieste." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/126466.
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Este trabalho propõe estudar a obra de Eladio Dieste, engenheiro uruguaio que desenvolveu a técnica da Cerâmica Armada ao longo de sua trajetória profissional, entre meados dos anos 40 até o final da década de 90 do século passado. O texto procura estabelecer uma aproximação ao seu trabalho focando em aspectos intrínsecos ao seu pensamento e sua obra construída. Para tanto, estabelece o tijolo, por se tratar do material onipresente em todas suas obras, como pivô da crítica arquitetônica, e o pensamento estrutural, como fio condutor. Nessa abordagem, que entende esses elementos como os constituintes de um núcleo de princípios projetuais do engenheiro, regras operativas baseadas em tipos estruturais se articulam para formar obras dos mais variados portes e usos. Para tanto o texto foi organizado da seguinte forma: nas Considerações Inicias são apresentados o estado da questão, a metodologia utilizada e a forma com que o trabalho foi organizado. A seguir, em Gênese, buscou-se resgatar a formação do profissional e o ambiente que propiciou o seu de desenvolvimento, parte das influências recebidas no desenvolvimento das coberturas em abóbada e a obra inaugural da técnica referida. Em Discurso Disciplinar é examinado, à luz da metodologia proposta, o uso do tijolo e o pensamento estrutural, bem como são descritos os tipos estruturais que compõe o repertório do projetista. Estudos de Caso, ao final do texto, é a unidade em que se faz o exame de obras singulares. São apresentadas situações concretas, em que é feita uma descrição e análise de aspectos formais, programáticos e conceituais da obra de Eladio Dieste. Estudos de Caso se apresentada, ainda, como verificação material das questões metodológicas desenvolvidas ao longo do trabalho.This dissertation aim to study the work of Eladio Dieste, Uruguayan engineer who developed the technique of Cerâmica Armada throughout his career, from the mid- 40s to the late 90s of the last century. It seeks to establish an investigative approach of Dieste’s production focusing on inherent aspects of his ideas and works. Therefore, establishes the brick, considering its ubiquity in all of his work, as an architectural criticism pivot, and Dieste’s structural thinking as a guideline. According to this approach, which considers these elements as parts of Dieste’s design principles hardcore, operational rules based on structural types are linked to create work pieces of different scales and uses. The dissertation was this way organized: at Considerações Iniciais it is introduced the state of the art, the methodology used and the way the work was organized. Then, at Gênese, was attempted to recue Dieste’s professional formation and its background, influences taken on the development of the vaults and this technique in his very first work. At Discurso disciplinar, describing structural types repertorie, Dieste’s brick use and structural thinking are examined throughout the methodology proposed. At Estudos de Caso, verifying the methodology question used, singular works by Eladio Dieste are described and analyzed regarding formal, programmatic and conceptual aspects.
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MEIN, MIREILLE. "Surveillance acoustique de moteurs diesel." Le Mans, 1997. http://www.theses.fr/1997LEMA1008.
Full textAbstract:
L'objectif de ce travail est de determiner la faisabilite d'une surveillance acoustique des diesels de secours des centrales nucleaires. Les principales difficultes de cette etude proviennent de la non-stationnarite des signaux acoustiques a traiter, et de la forte reverberation des locaux. Le choix d'une approche acoustique, a caractere novateur, est justifie par le retour d'experience de ces materiels et par l'attrait d'un systeme base sur une instrumentation simple. En effet, un certain nombre de defauts types sont detectes de facon auditive par le personnel de service, ce qui laisse presager de l'efficacite d'un systeme de surveillance acoustique base sur une instrumentation restreinte et non intrusive. Le recensement des defauts rencontres sur ces materiels a permis de degager trois systemes interessant la surveillance acoustique : la distribution (culbuterie, soupapes), l'injection (injecteurs, pompes a injection) et la suralimentation (turbo-compresseurs, collecteurs d'echappement). La caracterisation de defauts a ete entreprise par analyse de signaux acoustiques enregistres sur des moteurs : des campagnes de mesures ont ete menees sur des diesels en exploitation sur site nucleaire ou sur banc d'essai constructeur. L'analyse des signaux acoustiques enregistres a proximite des sources defaillantes a permis la caracterisation partielle de dereglage de jeux aux culbuteurs. Un systeme de detection automatique base sur une demarche de type reconnaissance des formes a ete mis au point pour la detection de quatre dereglages differents des jeux aux culbuteurs ; il presente de bonnes performances de reconnaissance independamment du cylindre affecte, et on montre qu'il est transposable sur un autre moteur. On peut envisager a partir de ce systeme, l'implantation sur site d'une maquette de surveillance temps reel utilisant un microphone mobile sur chaque rangee de cylindres. D'autres perspectives sont proposees pour la surveillance acoustique, avec en particulier la simulation en conditions reelles de defauts de type additifs tels que ceux pouvant affecter le systeme de suralimentation (detonation, fuite). Cette possibilite pourra etre exploitee pour l'elaboration d'un systeme de surveillance complementaire utilisant des capteurs fixes places au dessus du moteur.