Made available in DSpace on 2014-12-17T15:01:52Z (GMT). No. of bitstreams: 1 ManoelRF_TESE_PARCIAL.pdf: 3699462 bytes, checksum: 4db868ae1dcdf8497e51d1aa5771684c (MD5) Previous issue date: 2011-05-16 / The industry, over the years, has been working to improve the efficiency of diesel engines. More recently, it was observed the need to reduce pollutant emissions to conform to the stringent environmental regulations. This has attached a great interest to develop researches in order to replace the petroleum-based fuels by several types of less polluting fuels, such as blends of diesel oil with vegetable oil esters and diesel fuel with vegetable oils and alcohol, emulsions, and also microemulsions. The main objective of this work was the development of microemulsion systems using nonionic surfactants that belong to the Nonylphenols ethoxylated group and Lauric ethoxylated alcohol group, ethanol/diesel blends, and diesel/biodiesel blends for use in diesel engines. First, in order to select the microemulsion systems, ternary phase diagrams of the used blends were obtained. The systems were composed by: nonionic surfactants, water as polar phase, and diesel fuel or diesel/biodiesel blends as apolar phase. The microemulsion systems and blends, which represent the studied fuels, were characterized by density, viscosity, cetane number and flash point. It was also evaluated the effect of temperature in the stability of microemulsion systems, the performance of the engine, and the emissions of carbon monoxide, nitrogen oxides, unburned hydrocarbons, and smoke for all studied blends. Tests of specific fuel consumption as a function of engine power were accomplished in a cycle diesel engine on a dynamometer bench and the emissions were evaluated using a GreenLine 8000 analyzer. The obtained results showed a slight increase in fuel consumption when microemulsion systems and diesel/biodiesel blends were burned, but it was observed a reduction in the emission of nitrogen oxides, unburned hydrocarbons, smoke index and f sulfur oxides / A ind?stria, ao longo dos anos, vem trabalhando no sentido de melhorar a efici?ncia dos motores. Mais recentemente surgiu, tamb?m, a necessidade de reduzir as emiss?es de poluentes para se adequar ?s severas leis ambientais. Isto tem despertado o interesse de desenvolver pesquisas no sentido de substituir os combust?veis derivados do petr?leo por diversos tipos de combust?veis menos poluentes, tais como: misturas de ?leo diesel com ?steres de ?leos vegetais e ?leo diesel com ?leos vegetais e ?lcool, emuls?es e microemuls?es. Este trabalho tem como objetivo desenvolver sistemas microemulsionados a partir de tensoativos n?o i?nicos dos grupos nonilfenois etoxilados e ?lcoois l?uricos etoxilados, misturas com etanol/diesel e misturas diesel/biodiesel para uso em motores diesel. Em uma primeira fase, visando selecionar os sistemas microemulsionados, foram obtidos diagramas tern?rios das misturas, sendo os sistemas compostos por: tensoativos n?o-i?nicos, ?gua como fase polar e como fase apolar o diesel e/ou misturas diesel/biodiesel. Os sistemas microemulsionados e as misturas, que representam os combust?veis estudados, foram caracterizados quanto ? massa espec?fica, a viscosidade, o ?ndice de cetano e o ponto de fulgor. Tamb?m foram avaliados o efeito da temperatura nos sistemas microemulsionados, o desempenho do motor, e as emiss?es de mon?xido de carbono, ?xidos de nitrog?nio, hidrocarbonetos n?o queimados e fuma?a de todos os sistemas. Os ensaios de consumo espec?fico e das emiss?es em fun??o da pot?ncia foram realizados em um motor de ciclo diesel em uma bancada dinamom?trica e o analisador de emiss?es GreenLine 8000. Os resultados mostraram um pequeno aumento no consumo espec?fico para os combust?veis microemulsionados, nas misturas diesel/biodiesel em rela??o ao diesel puro, por?m com uma redu??o nas emiss?es de ?xidos de nitrog?nio, hidrocarbonetos n?o queimados, ?ndice de fuma?a e ?xidos de enxofre

The goal of this master thesis is to analyse the potential of LNG for the Central European region with the emphasis on the strategic role of LNG imports in strengthening the energy security of the region and its possible role in replacing the traditional fuels in the transport sector of the Visegrad Group countries. The increasing availability of LNG, together with the predictions of its rapidly growing global supply in the following years, offers a window of opportunity for the Central European states. Particularly when it comes to their energy security, as the growing access to LNG supplies translates into a growing competition for the existing pipeline supplies from Russia. Furthermore, the thesis also focuses on the potential of LNG as an alternative fuel in the inland waterway and heavy duty road transportation of the Visegrad Group countries and the steps that these countries take to integrate LNG fuel in their transport sector.

This thesis analyses stated preferences for 4 different types of passenger ve- hicles (conventional, hybrid electric, plug-in hybrid, and battery electric vehi- cles). The discrete choice experiment survey was conducted in Poland in 2014. With the use of latent class model it was possible to identify and describe dis- tinct segments in the population with varying preferences for the propulsion technologies: groups with strong and weak preferences for conventional vehi- cles, segments preferring pure hybrid and plug-in hybrid electric vehicles, and a class in favour of battery electric vehicles. Even though it was found that on average consumers would require compensation up to 22,200zł (e5,311) to switch to using an electric vehicle, respective segments in the population would be willing to pay around 10,100zł (e2,417) for this change in case of pure hy- brid, around 21,400zł (e5,128) in case of plug-in hybrid, and around 92,800zł (e22,199) in case of battery electric vehicles.

My thesis is engaged in business development of company Iveco Czech Republic, s.r.o. I would like to review current situation and then work up plan how to improve this situation.

Shipping is the world’s largest mode of transportation, considering mass moved a distance: it is the most e˙effective way to carry large volumes far. In order for the shipping industry to keep its position and develop even further, efforts are made to increase efficiency and reduce the environmental footprint from the industry. More efficient ships, reduced fuel consumption, use of alternative fuels and exhaust gas treatment are some of the choices to reduce shipping’s environmental footprint and achieve the sustainability goal established by EU and enforced by the International Maritime Organization.Throughout the thesis, en evaluation of 18 energy efficiency measures and 4 alternative fuels is performed. Energy efficiency measures reduce a ship’s fuel consumption and alternative fuels substitutes fossil fuels with higher content of environmentally harmful content. The measures and fuels, covered in the study, are evaluated for nine representative container ship´s. Data from year 2016 are used for the nine container ships. The current procedure followed for new investments is analyzed for all measures and fuels for each ship, focused on the financial study of each measure and fuel. The results are then included in a risk and benefit analysis that introduces external aspects, not included in the traditional financial evaluation, that include: those that influence the ship and the ship’s environment and those affected by the ship’s operations.The main goal is to evaluate the possibilities to reduce emissions by considering these aspects and involve more stakeholders in the investment of measures and fuels for shipping to keep its position as the most efficient mode of transportation.

[pt] Esta dissertação explora os processos de decisão que envolvem a transição para combustíveis de baixo carbono no setor marítimo, uma indústria vital para o comércio global, mas também uma significativa fonte de emissões de gases de efeito estufa. A investigação é guiada pela Teoria Institucional e pela Perspectiva Multinível (MLP) sobre transições para a sustentabilidade, oferecendo uma análise abrangente de como pressões institucionais e a necessidade de sustentabilidade influenciam as práticas organizacionais e as decisões estratégicas na adoção de novas tecnologias energéticas. Este estudo destaca-se por aplicar e ampliar teorias estabelecidas no contexto específico das transições de combustíveis no setor marítimo, contribuindo tanto para a teoria quanto para a prática ao fornecer um modelo de tomada de decisão aprimorado para o uso de combustíveis alternativos. O estudo adota uma abordagem de métodos mistos, integrando uma revisão sistemática de literatura e uma pesquisa detalhada com stakeholders da indústria marítima. A revisão de literatura foca na identificação de lacunas existentes e na compreensão das dinâmicas institucionais e de mercado que impactam a adoção de tecnologias de baixo carbono. A pesquisa, por outro lado, coleta dados primários sobre as percepções, barreiras e facilitadores percebidos por profissionais do setor, utilizando tanto análises quantitativas quanto qualitativas para uma compreensão mais profunda das atitudes em relação à transição energética. Os resultados revelam que inovações tecnológicas e incentivos econômicos emergem como facilitadores críticos, enquanto barreiras significativas incluem custos iniciais elevados, limitações de infraestrutura e desafios regulatórios complexos. Mais importante ainda, o estudo identifica e discute o papel das pressões institucionais - coercitivas, normativas e miméticas - e como elas moldam comportamentos organizacionais em direção a práticas sustentáveis. A dissertação propõe um framework de tomada de decisão que integra essas pressões com considerações práticas, ajudando as empresas a alinhar suas estratégias operacionais com objetivos de sustentabilidade ambiental. O trabalho expande a aplicação da Teoria Institucional e MLP ao examinar como essas teorias podem ser inter-relacionadas e aplicadas para explicar a complexidade das transições para combustíveis mais limpos na indústria marítima. A pesquisa oferece às empresas marítimas um modelo estratégico para orientar a transição para combustíveis alternativos, enfatizando a importância de um ambiente regulatório de suporte, cooperação internacional e colaboração entre stakeholders para facilitar essa mudança. O estudo conclui que a transição para combustíveis alternativos no setor marítimo é profundamente influenciada por uma complexa interação de fatores tecnológicos, econômicos e institucionais. O framework de tomada de decisão proposto ajuda as empresas marítimas a compreender essas dinâmicas existentes e também tráz à tona o papel crucial da inovação tecnológica, avaliações de impacto abrangentes e o desenvolvimento de políticas e frameworks regulatórios eficazes. Por fim, a dissertação sugere uma agenda de pesquisa futura focada na análise de transições tecnológicas específicas e na evolução dos comportamentos institucionais em resposta a desafios ambientais globais. / [en] This dissertation, titled The Adoption of Alternative Fuels in the Maritime Sector, critically examines the decision-making processes in the maritime industry under the lens of Institutional Theory and the Multi-Level Perspective (MLP) on sustainability transitions. Employing a mixed-method approach, which integrates a comprehensive literature review with a detailed survey, the study explores how institutional pressures and sustainability transitions influence the shift toward low-carbon fuels in maritime operations. The research identifies key enablers such as technological innovations and economic incentives, and addresses barriers including high initial costs, infrastructural limitations, and regulatory challenges. It also highlights the significant influence of coercive, normative, and mimetic pressures in shaping organizational behaviours towards sustainable practices. A novel decision-making framework that synthesizes insights from Institutional Theory and MLP is proposed to facilitate the adoption of alternative fuels, supporting maritime companies in navigating the complexities of sustainability transitions. A research agenda is also put forward. The practical relevance of this study lies in its strategic framework, which provides actionable insights for maritime companies pursuing environmental sustainability. Academically, the dissertation makes a significant theoretical contribution by applying and extending Institutional Theory and MLP within the context of maritime fuel transitions, enhancing our understanding of the interplay between institutional dynamics and sustainability practices in the maritime industry.

Desenvolveu-se um sistema de alimentação misto para motores de ignição por compressão turboalimentados, o qual utiliza diesel injetado normalmente na câmara de combustão e etanol pós-vaporizado, injetado líquido no coletor de admissão e vaporizado pela grande disponibilidade de energia contida no ar comprimido. Foram possíveis substituições de até 55% da massa de diesel por etanol; funcionamento regular e repetitivo foi verificado, resultado da admissão de álcool na forma de vapor. Constatou-se que o rendimento térmico e as emissões de gases poluentes eram bastante influenciados pelo sistema de alimentação desenvolvido: ganhos de até 25,6% no rendimento térmico foram possíveis com reduções máximas de 81% na emissão de material particulado e 80% em NOx, pela queima mais eficiente do diesel na presença do vapor de etanol. Reduções notáveis na temperatura do ar comprimido foram atingidas, possibilitando a substituição dos \"intercoolers\". A análise teórica da implantação do sistema desenvolvido, numa frota de veículos de transporte coletivo da região metropolitana de São Paulo, indicou viabilidade econômica e ambiental. / It was developed a supplementary fueling system for turbocharged compression ignition, which uses diesel injected usually in the combustion chamber and post-vaporized ethanol, that is injected in the liquid state inside the intake manifold and vaporized by the energy in the compressed air. It was possible to replace up to 55% of the diesel mass by ethanol; regular and repetitive operation was verified, result of the alcohol induction in the vapor state. It was verified that engine\'s efficiency and pollutant gases emissions were quite influenced by the fueling system developed: improvements of up to 25,6% in the efficiency were possible, with maximum reductions of 81% in particulate matter and 80% in NOx, as a result of a more efficient diesel oxidation in presence of ethanol vapor. Notable reductions in the compressed air temperature were reached, making possible the substitution of the \"intercoolers\". The theoretical analysis to implantation of the developed system, on vehicles of public transportation in the metropolitan area of São Paulo, indicated economical and environmental viability.

Desenvolveu-se um sistema de alimentação misto para motores de ignição por compressão turboalimentados, o qual utiliza diesel injetado normalmente na câmara de combustão e etanol pós-vaporizado, injetado líquido no coletor de admissão e vaporizado pela grande disponibilidade de energia contida no ar comprimido. Foram possíveis substituições de até 55% da massa de diesel por etanol; funcionamento regular e repetitivo foi verificado, resultado da admissão de álcool na forma de vapor. Constatou-se que o rendimento térmico e as emissões de gases poluentes eram bastante influenciados pelo sistema de alimentação desenvolvido: ganhos de até 25,6% no rendimento térmico foram possíveis com reduções máximas de 81% na emissão de material particulado e 80% em NOx, pela queima mais eficiente do diesel na presença do vapor de etanol. Reduções notáveis na temperatura do ar comprimido foram atingidas, possibilitando a substituição dos \"intercoolers\". A análise teórica da implantação do sistema desenvolvido, numa frota de veículos de transporte coletivo da região metropolitana de São Paulo, indicou viabilidade econômica e ambiental. / It was developed a supplementary fueling system for turbocharged compression ignition, which uses diesel injected usually in the combustion chamber and post-vaporized ethanol, that is injected in the liquid state inside the intake manifold and vaporized by the energy in the compressed air. It was possible to replace up to 55% of the diesel mass by ethanol; regular and repetitive operation was verified, result of the alcohol induction in the vapor state. It was verified that engine\'s efficiency and pollutant gases emissions were quite influenced by the fueling system developed: improvements of up to 25,6% in the efficiency were possible, with maximum reductions of 81% in particulate matter and 80% in NOx, as a result of a more efficient diesel oxidation in presence of ethanol vapor. Notable reductions in the compressed air temperature were reached, making possible the substitution of the \"intercoolers\". The theoretical analysis to implantation of the developed system, on vehicles of public transportation in the metropolitan area of São Paulo, indicated economical and environmental viability.

The purpose of this study was to determine consumers' attitudes toward and perceptions of global warming and hybrid cars and examine the car purchasing behavior in Singapore. The benefits of the study will provide marketers with insight of consumers' demand for cars in Singapore. Findings will help automakers develop more effective, consumer-oriented advertising plans for cars in Asia as Singapore consists of diverse Asian ethnic backgrounds- Chinese, Indian, and Malaysain.

Atomization of fuel is an important pre-requisite for efficient combustion in devices such as gas turbines, liquid propellant rocket engines, internal combustion engines and incinerators. The overall objective of the present work is to explore air-assisted atomization strategies for high viscosity fuels and liquids. Air-assisted atomization is a twin-fluid atomization method in which energy of the gas is used to assist the atomization of liquids. Broadly, three categories of air-assisted injection, i.e., effervescent, impinging jet and pre-filming air-blast are studied. Laser-based diagnostics are used to characterize the spray structure in terms of cone angle, penetration and drop size distribution. A backlit direct imaging method is used to study the macroscopic spray characteristics such as spray structure and spray cone angle while the microscopic characteristics are measured using the Particle/droplet imaging analysis (PDIA) technique. Effervescent atomization is a technique in which a small amount of gas is injected into the liquid at high pressure in the form of bubbles. Upon injection, the two-phase mixture expands rapidly and shatters the liquid into droplets and ligaments. Effervescent spray characteristics of viscous fuels such as Jatropha and Pongamia pure plant oils and diesel are studied. Measurements are made at various gas-to-liquid ratios (GLRs) and injection pressures. A Sauter Mean Diameter (SMD) of the order of 20 µm is achieved at an injection pressure of 10 bar and GLR of 0.2 with viscous fuels. An image-based method is proposed and applied to evaluate the unsteadiness in the spray. A map indicating steady/unsteady regime of operation has been generated. An optically accessible injector tip is developed which has enabled visualization of the two-phase flow structure inside the exit orifice of the atomizer. An important contribution of the present work is the correlation of the two-phase flow regime in the orifice with the external spray structure. For viscous fuels, the spray is observed to be steady only in the annular two-phase flow regime. Unexpanded gas bubbles observed in the liquid core even at an injection pressure of 10 bar indicate that the bubbly flow regime may not be beneficial for high viscosity oils. A novel method of external mixing twin-fluid atomization is developed. In this method, two identical liquid jets impinging at an angle are atomized using a gas jet. The effect of liquid viscosity (1 cP to 39 cP) and surface tension (22 mN/m to 72 mN/m) on this mode of atomization is studied by using water-glycerol and water-ethanol mixtures, respectively. An SMD of the order of 40 µm is achieved for a viscosity of 39 cP at a GLR of 0.13 at a liquid pressure of 8 bar and gas pressure of 5 bar. It is observed that the effect of liquid properties is minimal at high GLRs where the liquid jets are broken before the impingement as in the prompt atomization mode. Finally, a pre-filming air-blast technique is explored for transient spray applications. An SMD of 22 µm is obtained with diesel at liquid and gas pressures as low as 10 bar and 8.5 bar, respectively. With this technique, an SMD of 44 µm is achieved for Jatropha oil having a viscosity 10 times higher than that of diesel.