Dissertations / Theses on the topic 'Low emission vehicles'

The impact of a change in emissions abatement technology, fuel or vehicle on carbon dioxide (CO) 2 and toxic air pollutant emissions derived from road transport was investigated. Road transport emissions were calculated and non-mobile source emissions rates were compiled for the base year 2005 for the City of Leicester, which was the case study for the research. Factor and cluster analysis were applied so that roads could be classified into groups, allowing diurnal traffic profiles to be assigned to roads with similar attributes prior to air quality modelling and to enable the characteristics of typical roads in Leicester to be identified. Five road classifications were developed. The emissions inventory compiled along with meteorological data, background pollutant concentration values and the five diurnal traffic profiles were input into an air quality model. The BOOT evaluation framework (Chang and Hanna 2005) was used to statistically evaluate the performance of the air quality model through comparisons of predicted and observed pollutant concentrations. The model was found to significantly over-predict and under-predict concentrations of nitrogen dioxide (NO) and particles with a diameter of less than ten microns (PM) at seven and five 210 monitoring locations across Leicester. A discussion of the sources of error in prediction was presented. The base-case was edited to reflect a change in emissions abatement technology, fuel or vehicle and emissions were recalculated. In addition, a vehicle kilometres travelled (VKT) restriction was imposed on the vehicle fleet that did not allow any increase in VKT from the base year. The changes to the base-case were made in increments of 5% until 100% was reached. Regression analysis was used to create 13 models that allowed the impact of the road transport strategies on CO and pollutant 2 emissions to be explored. A reduction in both CO and toxic air pollutant emissions (‘win-win’) was found when the penetration 2 of zero emissions vehicles (ZEVs) and plug-in hybrid electric vehicles (PHEVs) to the car fleet was modelled. Overall, the highest reduction in toxic pollutant and CO emissions were found for ZEVs, 2 which represent electric vehicles (EVs) under current legislation. A 53% (or greater) penetration of ZEVs to the car fleet was the only strategy for which a 50% reduction in CO for a 1990 base was 2 found. Therefore, this indicates that substantial and arguably radical changes are required if air quality and climate change limit values and targets to be achieved. A win-win for air quality and climate change was found when new emissions abatement technology was introduced into the car fleet. However, greater pollutantemissions reductions were observed with the introduction of new emissions abatement technology to light goods vehicle (LGV) and heavy goods vehicle (HGV) stocks. These strategies were found to have a negligible impact on CO 2 emissions. Consequently a trade-off was found where a ‘win-win’ was achieved through changes to the car fleet but at the cost of higher pollutant emissions reductions from other strategies. The introduction of new emissions abatement technology to the bus fleet on roads predominantly on key traffic corridors within Leicester’s air quality management area (AQMA) resulted in substantial air quality benefits. The same strategy did not result in a reduction in CO emissions. However, in the 2 context of an overall sustainable transport strategy the benefits of increasing bus patronage, which in turn may reduce the number of single occupancy vehicles on the road, is likely to have a more than compensatory effect. Substantial pollutant emissions reductions were found as a result of the introduction of new emissions abatement technology into the HGV and LGV fleets. However, these strategies were found to have negligible CO emissions reductions and therefore did not provide a win-win for air quality and climate change. Similarly, a win-win from the introduction of LPG to the car fleet was not found. Therefore, the uptake of LPG or investment in the introduction of new emissions abatement technology to the LGV or HGV fleets should only be considered as a part of a sustainable policy package that comprises other measures, such as logistics optimisation or a reduction in VKT. The findings of this research were used to inform a set of policy actions for Leicester City Council.

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.

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.

[EN] The automotive industry is currently experiencing one of its most rapidly changing periods in recent decades, driven by a growing interest in reducing the negative environmental impacts caused by fossil fuels consumption and the resulting carbon dioxide (CO2) emissions generated during the operation of the internal combustion engine (ICE) which have proven to contribute significantly to Global Warming. Given the fact that a total replacement of the current fleet, dependent of fossil fuels, is unlikely to happen in the immediate future and the urgency to reducing CO2 emissions from transportation in order to tackle Global Warming, it is possible to say that optimizing current ICE technologies and conventional vehicles and engines is a first order priority. Among the technical solutions developed to improve the efficiency of ICE, low viscosity engine oils (LVEO) have emerged as an effective and low-cost method that provides reductions in fuel consumption between 0.5% and 5%. During the development of this thesis, a test plan focused on determining fuel consumption reduction when low viscosity oils are used in light duty vehicles (LDV) and heavy duty vehicles (HDV) were carried out. The test plan has been divided in three parts; the first part was focused on the study of light-duty vehicles (LDV) using one diesel engine representative of the European market. During this part three testing modes were used: comparative motored, fired stationary points and transient homologation cycle tests. All test were performed in the engine test bed. The second part of the study consisted of another comparative test, this time using a different engine oils in a HDV fleet. The study was conducted using the urban buses fleet of the city of Valencia, including 3 buses models , with 2 different powertrain technologies. The third part of the study was focused on the friction coefficient behavior within the engine tribological pairs making comparative tests in two specialized tribometers; one of reciprocating action to simulate the lubrication conditions in the piston ring-cylinder liner contact and a "ball-on-disk" tribometer to simulate the lubrication in the distribution system. The various comparative studies have served to analyze how the friction and fuel consumption responded when LVEO were used both in the ICE and the complete vehicle contexts. The fuel consumption benefit found during the test was used to calculate the carbon footprint reduction when LVEO were used.<br>[ES] Actualmente la industria de la automoción vive uno de los periodos de cambio más vertiginosos de las últimas décadas, marcado por un creciente interés en reducir los impactos medioambientales negativos generados por el consumo de combustibles fósiles y sus consecuentes emisiones nocivas de dioxido de carbono (CO2) generados durante el funcionamiento del motor de combustión interna alternativo (MCIA). Teniendo en cuenta que el proceso de sustitución de la flota actual por una totalmente independiente de los combustibles fósiles puede tomar varias décadas, y ante la urgencia inmediata de reducir las emisiones de CO2, se puede decir que actualmente es más urgente hacer una optimización de los vehículos con motorizaciones convencionales. Entre las soluciones técnicas que se han desarrollado para mejorar la eficiencia del MCIA destaca la utilización de aceites de baja viscosidad como un método efectivo y de bajo coste de implementación que brinda reducciones del consumo entre el 0.5% y el 5%. Durante el desarrollo de esta tesis se ha llevado a cabo un plan de ensayos enfocado en determinar valores concretos de ahorro de combustible esperados cuando se utilizan aceites de baja viscosidad en vehículos de trabajo ligero y pesado. El plan de estudios se dividió en tres partes; la primera se centró en el estudio de MCIA de vehículos de trabajo ligero, utilizando un motor Diesel representativo del mercado Europeo y llevando a cabo pruebas comparativas en arrastre, puntos de funcionamiento estacionarios y ciclos transitorios de homologación. La segunda parte del estudio consta de otro ensayo comparativo, esta vez utilizando una flota de vehículos de trabajo pesado. El estudio se realizó con la flota de autobuses urbanos de la ciudad de Valencia, incluyéndose 3 modelos de autobuses, con 2 tipos de motorización diferente. La tercera parte del estudio se centró en el comportamiento del coeficiente de friction en los pares tribológicos del motor haciendo ensayos comparativos con tribómetros especializados; uno de movimiento alternativo para simular las condiciones de la interfaz piston-camisa y un "bola y disco" para simular la lubricación en el sistema de distribución, específicamente en la interfaz leva-taqué. Los diversos estudios comparativos han servido para analizar como es la respuesta general de la fricción y el consumo de combustible cuando se usan aceites de baja viscosidad, tanto a nivel de motor como para la totalidad del vehículo, encontrando diferencias de par en los ensayos de arrastre, de consumo específico de combustible en los ensayos de motor en estado estacionario y diferencias totales de consumo de combustible en los ensayos en régimen transitorio y en flota, que a su vez han permitido estimar la reducción esperada en la huella de carbono.<br>[CAT] Actualment la indústria de l'automoció viu un dels períodes de canvi més vertiginoses de les últimes dècades, marcat per un creixent interès en reduir els impactes mediambientals negatius generats pel consum de combustibles fòssils i els seus conseqüents emissions nocives de diòxid de carboni (CO2) generats durant el funcionament del motor de combustió interna alternatiu (MCIA). Tenint en compte que el procés de substitució de la flota actual per una totalment independent dels combustibles fòssils pot prendre diverses dècades, i davant la urgència immediata de reduir les emissions de CO2, es pot dir que actualment és més urgent fer una optimització dels vehicles amb motoritzacions convencionals. Entre les solucions tècniques que s'han desenvolupat per millorar l'eficiència del MCIA destaca la utilització d'olis de baixa viscositat com un mètode efectiu i de baix cost d'implementació que brinda reduccions del consum entre el 0.5% i el 5%. Durant el desenvolupament d'aquesta tesi s'ha dut a terme un pla d'assajos enfocat a determinar valors concrets d'estalvi de combustible esperats quan s'utilitzen olis de baixa viscositat en vehicles de treball lleuger i pesat. El pla d'estudis es va dividir en tres parts; la primera es va centrar en l'estudi de MCIA de vehicles de treball lleuger, utilitzant un motor dièsel representatiu del mercat Europeu i portant a terme proves comparatives en arrossegament, punts de funcionament estacionaris i cicles transitoris d'homologació. la segona part de l'estudi consta d'un altre assaig comparatiu, aquest cop utilitzant una flota de vehicles de treball pesat. L'estudi es va realitzar amb la flota d'autobusos urbans de la ciutat de València, incloent-se 3 models d'autobusos, amb 2 tipus de motorització diferent. La tercera part de l'estudi es va centrar en el comportament del coeficient de friction en els parells tribològics del motor fent assajos comparatius amb tribómetros especialitzats; Un acció reciprocante per simular les condicions del piston camisa i un bola i disc per simular la lubricació en el sistema de distribució. Els diversos estudis comparatius han servit per analitzar com és la resposta general de la fricció i el consum de combustible quan es fan servir olis de baixa viscositat, tant a nivell de motor com la totalitat del vehicle, trobant diferències de bat a els assajos d'arrossegament, de consum específic de combustible en els assajos de motor en estat estacionari i diferències totals de consum de combustible en els assajos en règim transitori i en flota, que al seu torn han permès calcular la reducció en la petjada de carbono.<br>Ramírez Roa, LA. (2016). Contribution to the Assessment of the Potential of Low Viscosity Engine Oils to Reduce ICE Fuel Consumption and CO2 Emissions [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/73068<br>TESIS

Es werden Möglichkeiten untersucht, das Kaltstart- und Warmlaufverhalten von Ottomotoren mit Sekundärlufteinblasung zu optimieren. Das für die Untersuchungen eingesetzte, innovative Sekundärlufteinblasesystem mittels Sekundärluftlader weist aufgrund der Baugröße, des Gewichts, der Leistungsfähigkeit und insbesondere der einfachen, thermodynamischen Betätigung Potenziale auf, die bisher eingesetzte Sekundärluftpumpe zu ersetzen. Den experimentellen Untersuchungen wurde die Entwicklung der Abgasgesetzgebung sowie eine theoretische Betrachtung der Entstehungsmechanismen von Abgasemissionen vorangestellt. Mittels eines Simulationsmodells werden die Abhängigkeiten des Sekundärluftladers von den motorischen Randbedingungen abgebildet. Somit kann eine Vorauswahl für das Luftmassenförderverhalten des Sekundärluftladers bei unterschiedlichen Einsatzbereichen getroffen werden. Die im Start- und Warmlauf, ebenso im Lastwechsel, gemessenen Ergebnisse wurden zur Analyse der Emissionsverbesserungsmechanismen eingesetzt. Insbesondere der Einblasezeitpunkt der Sekundärluft und das Hochlaufverhalten des Sekundärluftsystems zeigen einen enormen Einfluss auf die Höhe der Rohemissionen. Eine Gegenüberstellung aller gemessenen Varianten mit Sekundärluftpumpe und Sekundärluftlader zeigt einen deutlichen Emissionsvorteil des Sekundärluftladersystems. Zusätzlich bewirkt der Sekundärluftlader, durch die Bordnetzentlastung eine Motorlastabsenkung bei verbessertem Ansprechverhalten und höherem Sekundärluftmassenstrom. Ergebnis ist eine Verringerung der HC-Rohemissionen zwischen 20% und 30%. Die Vorteile im Gewicht und Bauvolumen sowie der geringere Verkabelungsaufwand runden die deutlichen Vorteile des Sekundärluftladers gegenüber der Sekundärluftpumpe ab. Durchgeführte Untersuchungen bei Tieftemperatur (-7°C) und unter Höhenbedingungen haben ebenfalls Vorteile gegenüber der Sekundärluftpumpe ausgewiesen. Die theoretische Abschätzung des Einsatzfeldes für den Sekundärluftlader ist ab einem Hubraum von 1,2°l Hubraum durchgeführt und als positiv bewertet worden<br>The paper investigates possible ways of optimizing the cold-start and warm-up performance of gasoline engines with secondary air injection. Due to its size, weight, performance capability, and especially its simple, thermodynamic operation the innovative secondary air injection system used for the investigations and featuring a secondary air charger has the potential to replace the secondary air pump used to date. The experimental investigations are preceded by the development of exhaust emission legislation and a theoretical analysis of the process leading to exhaust emissions. A simulation model is used to illustrate the dependencies of the secondary air charger on boundary engine conditions. Consequently it is possible to make a preselection for the air mass conducting properties of the secondary air charger in various fields of application. The results obtained by measurement in starting, warm-up, and in load changes, were used to analyze the emission improvement processes. The level of raw emissions is affected enormously by the time of injection of secondary air and the acceleration performance of the secondary air system. A comparison of all the measured variants with the secondary air pump and secondary air charger indicates that the secondary air charger system has a distinct emission advantage. In addition, by relieving the vehicle power supply the secondary air charger brings about a reduction in engine load, improved response, and higher secondary air mass flow. The result is a 20% to 30% reduction in raw HC emissions. The significant advantages over the secondary air pump are rounded off by benefits in terms of weight and bulk volume and a reduction in the amount of wiring. Tests conducted at low temperature (-7°C) and under high altitude conditions have also indicated advantages over the secondary air pump

Táto diplomová práca je zameraná na preukazovanie vplyvov rôznych architektúr spätnej recirkulácie spalín na preplňované benzínové motory. Simulácie boli vytvorené v termodynamickom simulačnom programme GT-Power. Práca začína porovnávaním vplyvov spätnej recirkulácie na ustálené stavy motora, najmä z hľadiska spotreby, ktoré sú následne implementované do tranzientných modelov, simulujúc emisné testovacie cykly. Na konci práce sa venujem vplyvom spätnej recirkulácie na funkciu oxidačno-redukčného katalyzátora a na funkciu turbodúchadla.

碩士<br>大葉大學<br>工學院碩士在職專班<br>101<br>This study aims to discuss change status of exhaust smoke for diesel vehicles using three oils such as Premium Diesel, B1 biodiesel and B2 biodiesel, etc. under four driving states of no-load and rapid acceleration, full load and 100% steady acceleration, full load and 60% steady acceleration and full load and 40% steady acceleration. The test result shows exhaust smoke for vehicles is decreasing after low percentage biodiesel is used; exhaust smoke is not decreasing but increasing after adding percentage of biodiesel is increased. The study further explores it has something to do with lubricating quality of biodiesel that adding B1 biodiesel can remove carbon disposition in older engine of a vehicle to increase effectiveness of engine for complete combustion, causing vehicle to decrease exhaust smoke. However, adding B2 biodiesel will decrease lubrication effect due to sulphur content decreases to less than 10ppm, causing exhaust smoke to rise again. Additionally, the test shows adding biodiesel will improve exhaust smoke of older vehicles but deteriorate that of vehicles under 8 years old. This study also analyzes the test result for disqualified vehicles exceeding 40% exhaust smoke. B1 biodiesel used in no-load test (pressing accelerator pedal in idle speed) can decrease 8% average exhaust smoke, and B2 biodiesel added afterwards will cause exhaust smoke to rise 7% again but sill lower than that by adding PD; B1 biodiesel used in full load test (in driving state) can decrease 6~37% average exhaust smoke, and B2 biodiesel added afterwards will cause smoke exhaust to rise 2~6% again but sill lower than that by adding PD .Therefore, adding biodiesel actually can improve obvious smoke exhaust of disqualified vehicles.

碩士<br>國立交通大學<br>環境工程系所<br>100<br>For improving ambient air quality, subsidy for low emission buses is a widely adopt policy to reduce mobile source pollution. Since the cost for replacing buses with low emission vehicles is quite high, prioritizing bus routes for increasing the effectiveness of the subsidy policy is thus desired. Therefore, this study establishes indicators to evaluate the subsidy priority of a bus route according to simulated pollutant concentration and affected population along the route. Since there are too many bus routes in the studied area, Taipei City, this study excludes those routes with obviously low pollution impact first. Then, the Operational Street Pollution Model (OSPM) is applied to simulate the mobile source pollution along each route based on estimated traffic flow, buildings on both sides, and meteorological data. Two sets of indicators are established. The first set is computed according to pollutant concentration and route length, and the other is based on the estimated pollutant intake sum by affected population. Indicators for individual pollutants are established first. For comparing the results obtained for different pollutants, the Acute Reference Exposure Level (RELA) and Air Quality Standard are applied to establish the other sets of indicators. Finally, aggregate indictors are set up by adding up all indicators for individual pollutants. The applicability of each indicator for prioritizing bus routes for subsidy is then evaluated. Seventy-five routs with obviously low pollution impact are removed during the initial screening procedure. For the rest of routes, according to the trip length of each route, the top 100 routes are selected for further analyses. The results simulated by OSPM are mainly affected by street width, building height, and traffic flow. Because the impact on affected population along a route should be considered, the intake-sum indicators are thus recommended for prioritizing bus routes. Although the CO, PM10, PM2.5 indicators are highly correlated, others are not. For individual pollutant based indicators, either the PM10, as the major PSI critical pollutant, or CO indicator is suggested. However, different pollutants have varied impacts on human, and the indicator based on one individual pollutant may not represent the overall effect from all pollutants. The aggregate indicator is therefore recommended for prioritizing bus routes for low emission vehicle subsidy.

The objective of this study was to investigate and compare the brokered transport costs of road and rail transport for the independent timber growers of NCT Forestry Co-operative Limited in Kwa-Zulu-Natal. Reliability, flexibility, visibility, rates and total transport time were evaluated for each mode of transport. The impact of the carbon emissions was also considered and the option of performance based standard vehicles investigated. During the period 2000 to 2003, rail was the dominant mode of transport. However from 2004 onwards, due to the diminishing service levels and the high tariff structures of rail transport, road became the preferred mode of transport. The results of the survey conducted for the purposes of this study showed that although road transport outperformed rail transport, rail transport scored significantly higher than road transport as a cost-effective mode of transportation. Rail transport was shown to be a far less carbon intensive mode of transport than road transport, while there were substantial cost savings and benefits from performance based standard vehicles.<br>Transport Economics, Logistics and Tourism<br>M. Com. (Logistics)