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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Electric roads as future road transport : A study of Electric Road System (ERS) to facilitate sustainable road transport for passenger cars

Nashed, Rose-Marie January 2019 (has links)
Sweden is a geographically large and sparsely populated country, with a need for road transport for individuals as well as for logistics. Domestic road transport largely contributes to air pollutions, where passenger cars account for the largest share. Looking ahead, the present rate of reduction of emissions is not enough to reach the climate targets of a fossil free transport sector.  Electric road system (ERS) has emerged to deal with drawbacks of electric vehicles. Several solutions are being evaluated at demonstration projects. Until now, ERS is mainly associated with heavy vehicles and the relation to passenger cars is not as clear, where this study explores the social advantages of ERS and passenger cars.  A case study is conducted, where an ERS implementation between Helsingborg and Malmö as part of the European route E6 in Sweden is modelled. The NPV with an economic lifespan of 20 years and an interest rate of 3.5 percent amounts to 350 MSEK, considered as high profitable. The CO2 emissions of the studied system would be reduced by 102 000 tonnes CO2, corresponding to a decrease of about 60 percent. Looking at the studied system, heavy trucks are contributing to the most impact. Nevertheless, there is great potential for passenger cars utilising ERS to decrease their emissions and fuel costs.  Several semi-structured interviews have been conducted to highlight the prevailing views of ERS and passenger cars and the impact of cost-benefit analysis (CBA) for decision-making of transport investments. Several diverse views of ERS and passenger cars exist. ERS is a large investment, where the main need is among heavy vehicles. However, the profitability would increase as the amount of vehicles utilising ERS increases. In a future road transport system, it is possible that several technologies such as ERS, fast chargers and autonomous vehicles could be utilised simultaneous, and complete each other rather than being substitutes. It is conceivable that ERS is planned out of the needs of heavy vehicles, where passenger cars might benefit of the system as well. More passenger cars would likely utilise ERS as it is implemented to a greater extent.  Further, CBA could provide a perception of the investment. However, it does not ensure that the projects are performed or chosen out of highest NPV, since several aspects besides the profitability are considered. Available information of ERS for CBA is yet limited and more data, such as effect relations is needed to facilitate well-founded decisions. In the future, it is likely that CBA of transport investments would become more complex, where several technologies would be considered. The transport sector will most likely alter, and existing assessment methods will presumably be adjusted in line with this. / Sverige är ett geografiskt stort och glesbefolkat land med ett stort behov av vägtransporter för såväl privatpersoner som för logistik. Inrikes vägtransport bidrar i stor utsträckning till luftföroreningar, där personbilar står för den största andelen av utsläppen. Den nuvarande minskningstakten av utsläpp är inte tillräcklig för att nå klimatmålen om en fossilfri transportsektor.  Elvägar (ERS) har utvecklats för att hantera utmaningar med elfordon. Flera lösningar av teknologin testas vid demonstrationsprojekt och hittills är ERS främst förknippat med tunga fordon. Dock är relationen till personbilar inte lika tydlig, där denna studie undersöker de samhälleliga fördelarna med ERS relaterat till personbilar.  En fallstudie har genomförts, där en installation av ERS mellan Helsingborg och Malmö som en del av E6 i Sverige modelleras. Nettonuvärdet med en ekonomisk livslängd på 20 år och en internränta om 3,5 procent uppgår till 350 MSEK, vilket betraktas som hög lönsam. Koldioxidutsläppen från det studerade systemet skulle minskas med 102 000 ton CO2, vilket motsvarar en minskning med drygt 60 procent. Utifrån det studerade systemet bidrar tunga lastbilar till den största inverkan. Likväl finns stor potential för personbilar att nyttja den installerade elvägen för att minska sina utsläpp och bränslekostnader.  Flera semistrukturerade intervjuer har genomförts för att lyfta fram de rådande synsätten på ERS och personbilar och effekterna av samhällsekonomiska analyser (CBA) vid beslutsfattande av transportinvesteringar. Det finns flera olika synsätt på ERS relaterat till personbilar. ERS är en stor investering, där det största behovet finns bland tunga fordon. Emellertid ökar lönsamheten med antalet fordon som använder systemet. I ett framtida vägtransportsystem är det möjligt att flera teknologier såsom ERS, snabbladdning av elbilar och autonoma fordon utnyttjas samtidigt och används som komplement istället för att ersätta varandra. Det är tänkbart att ERS planeras och installeras utifrån behoven hos tunga fordon, där även personbilar kan dra fördel av systemet. Dessutom är det sannolikt att fler personbilar skulle utnyttja ERS allteftersom det installeras i större utsträckning.  Vidare kan CBA ge en uppfattning om investeringen. Det säkerställer dock inte att projekten genomförs eller väljs utifrån högsta nettonuvärde, eftersom flera aspekter utöver lönsamheten beaktas. Tillgänglig information om ERS för CBA är ännu begränsad och mer data såsom effektsamband behövs för att säkerställa välgrundade beslut. I framtiden är det troligt att CBA av transportinvesteringar blir mer komplexa, där flera tekniker behöver beaktas. Transportsektorn kommer sannolikt att förändras, och befintliga bedömningsmetoder kommer förmodligen att anpassas i linje med detta.
22

Chemical and physical characterization of aerosols from the exhaust emissions of motor vehicles

Lim, McKenzie C. H. January 2007 (has links)
The number concentration and size distribution of particles in Brisbane have been studied extensively by the researchers at The International Laboratory for Air Quality and Health, Queensland University of Technology (Morawska et al., 1998, 1999a, 1999b). However, the comprehensive studies of chemical compositions of atmospheric particles, especially with regard to the two main classes of pollutants (polycyclic aromatic hydrocarbons and trace elements), that are usually of environmental and health interest, have not been fully undertaken. Therefore, this thesis presents detailed information on polycyclic aromatic hydrocarbons (PAHs) and elemental compositions of vehicle exhausts and of urban air in Brisbane. The levels of polycyclic aromatic hydrocarbons (PAHs) and elements in three of Brisbane's urban sites (Queensland University of Technology, Woolloongabba and ANZ stadium sites) were measured. The most common PAHs found in all sites were naphthalene, phenanthrene, anthracene, fluoranthene, pyrene and chrysene while Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Si, Sn, Sr and Zn were the most common elements detected in the total suspended particles and fine particle (PM2.5). With the aid of multivariate analysis techniques, several outcomes were obtained. For example: -- Major human activities such as vehicular and industrial sources were the most contributing pollution sources in Brisbane. However, these two sources have different influential strength on the compositions of the polycyclic aromatic hydrocarbons and trace inorganic elements found in the urban air. -- Woolloongabba bus platform was the most polluted site on the basis of the elemental and PAH compositions in its air samples while QUT site was the worst polluted site in terms of PM2.5 elemental contents. These results demonstrated that the impact of traffic related pollutants on Brisbane's urban air is significant. This led to the investigations of the direct emissions of pollutants from exhaust vehicular source in the second part of this research work. The exhaust studies included the investigations of PAHs, trace inorganic elements and particles. At the time of the study, the majority of vehicles in Brisbane used low sulfur diesel (LSD) fuel or unleaded petrol (ULP). However, the importance of vehicles using ultra low sulfur diesel (ULSD) and liquefied petroleum gas (LPG) is constantly growing. Therefore, the exhaust emission studies on chassis dynamometer from heavy duty non-catalyst-equipped buses powered by LSD and ULSD with 500 ppm and 50 ppm sulfur contents respectively as well as passenger cars powered by ULP and LPG were explored. The outcomes of such studies are summarized as follows: -- Naphthalene, acenaphthene, acenaphthylene, anthracene, phenanthrene, fluorene, fluoranthene and pyrene were frequently emitted by the buses powered by LSD and ULSD. However, buses powered by ULSD emitted 91% less PAHs than those powered by LSD. On the other hand, Mg, Ca, Cr, Fe, Cu, Zn, Ti, Ni, Pb, Be, P, Se, Ti and Ge were found in measurable quantities in the exhaust of the buses. The emissions of the elements were found to be strongly influenced by the engine driving conditions of the buses and fuel parameters such as sulfur content, fuel density and cetane index. -- Naphthalene, fluorene, phenanthrene, anthracene, pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene were predominantly emitted by ULP and LPG cars. On the average, the total emission factors of PAHs from LPG cars were generally lower than those of ULP cars, but given the large variations in the emission factors of cars powered by the same type of fuel, differences in the emission factors from both car types were statistically insignificant. In general, platinum group elements and many other elements were found in the exhausts of cars powered by both fuels. Emissions of inorganic elements from the cars were dependent on the type and the mileage of the cars. For example, ULP cars generally emitted higher levels of Cu, Mg, Al and Zn while LPG cars emitted higher level of V. In addition, cars with higher mileages were associated with higher emissions of the major elements (Zn, Al, Fe, V and Cu). -- Buses powered by ULSD usually emitted fewer particles, which were generally 31% to 59% lower than those emitted by LSD powered buses. Similarly, cars powered by LPG emitted less particles from those powered by ULP fuel. However, more nanoparticles (those with aerodynamic diameters of less than 50 nm) were emitted by LPG powered cars than their ULP counterparts. Health effect assessment of the exhaust PAHs was evaluated in terms of benzo(a)pyrene toxicity equivalent (BAPeq). The potential toxicities of PAHs emitted by ULSD powered buses were generally lower than those emitted by their LSD counterparts. A similar trend with lower emissions of PAHs from LPG cars than from ULP cars was observed when otherwise identical passenger cars were powered by LPG and ULP fuels. In summary, this thesis has shown that the majority of airborne particles found around Brisbane have anthropogenic origins, particularly vehicle emissions, and that fuel or lubricant formulations and engine operating conditions play important roles in the physical and chemical characteristics of pollutants emitted by vehicles. The implications of these results on worldwide strategies to reduce the environmental and health effects of particles emitted by motor vehicles were discussed. In this regard, direct emission measurements from vehicles powered by LSD, ULSD, ULP and LPG unveiled the relative environmental benefits associated with the use of ULSD in place of LSD to power diesel engines, and of LPG in place of ULP to power passenger cars.

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