903 resultados para Heavy duty vehicles
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Includes indexes.
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Mode of access: Internet.
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Estimating un-measurable states is an important component for onboard diagnostics (OBD) and control strategy development in diesel exhaust aftertreatment systems. This research focuses on the development of an Extended Kalman Filter (EKF) based state estimator for two of the main components in a diesel engine aftertreatment system: the Diesel Oxidation Catalyst (DOC) and the Selective Catalytic Reduction (SCR) catalyst. One of the key areas of interest is the performance of these estimators when the catalyzed particulate filter (CPF) is being actively regenerated. In this study, model reduction techniques were developed and used to develop reduced order models from the 1D models used to simulate the DOC and SCR. As a result of order reduction, the number of states in the estimator is reduced from 12 to 1 per element for the DOC and 12 to 2 per element for the SCR. The reduced order models were simulated on the experimental data and compared to the high fidelity model and the experimental data. The results show that the effect of eliminating the heat transfer and mass transfer coefficients are not significant on the performance of the reduced order models. This is shown by an insignificant change in the kinetic parameters between the reduced order and 1D model for simulating the experimental data. An EKF based estimator to estimate the internal states of the DOC and SCR was developed. The DOC and SCR estimators were simulated on the experimental data to show that the estimator provides improved estimation of states compared to a reduced order model. The results showed that using the temperature measurement at the DOC outlet improved the estimates of the CO , NO , NO2 and HC concentrations from the DOC. The SCR estimator was used to evaluate the effect of NH3 and NOX sensors on state estimation quality. Three sensor combinations of NOX sensor only, NH3 sensor only and both NOX and NH3 sensors were evaluated. The NOX only configuration had the worst performance, the NH3 sensor only configuration was in the middle and both the NOX and NH3 sensor combination provided the best performance.
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The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Maré Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.
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Raskaankaluston ajoneuvojen aerodynaaminen kehitys on kulkenut väärään suuntaan jo vuosisadan verran ja niiden muodon määräävä tekijä on kuljetustilan maksimointi ja toi-minnallisuus. Lähiaikoina on astumassa EU:ssa uusi direktiivi voimaan, joka sallii lisämas-san käyttämisen aerodynaamisiin lisäosiin. Työn tarkoituksena on tutkia mahdollisuuksia parantaa hakeperävaunun aerodynamiikkaa yksinkertaisilla lisäosilla. Työ on rajattu koskemaan perävaununetuosaan, -sivuosaan ja -pohjaan. Lisäksi rajoitteita asettaa Suomenlainsäädäntö ja EU:n direktiivit. Työssä perehdytään ilmanvastusvoiman syntymekanismeihin raskaankaluston ajoneuvojen kannalta ja käydään läpi merkittävimmät vaikuttavat tekijät ilmanvastusvoimiin sekä kuorma-auton perävaunun eri muotojen ja osien vaikutus. Perävaunuun asetettavien il-manohjaimien vaikutukset ja toiminta selvitetään. Avainasemassa hakeperävaunun aerodynamiikan parantamisessa on ilmavirtauksen estä-minen perävaunun alle sekä etupuolelta. Lisäksi virtausten muuttamien perävaunun takana on hyödyllistä. Merkittävimmät hyödyt saadaan niistä ratkaisuista, jotka estävät ilman virtausta perävau-nun alle sekä renkaisiin. Näitä ratkaisuja olivat sivuhelmat ja pohjan sekä renkaiden kote-lointi. Lisäksi ilmavirtauksen estäminen perävaunun edestä tuotti merkittävää hyötyä. Levy perävaunun välissä tai koko välin peittämällä saadaan aikaan huomattavaa vähenemistä ilmanvastuksessa.
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Ante el crecimiento económico y la transformación del país. Con el incremento de los flujos de comercio y el transporte, Bogotá, buscando reducir el impacto ambiental por la cantidad de vehículos y reducir la congestión, ha decidido implementar políticas públicas que restringen el ingreso de vehículos de carga pesada por la ciudad. Esto crea una necesidad de espacios a las afueras de la ciudad, cerca de las zonas logísticas y con la capacidad de ofrecer a los transportadores los servicios de alimentación, parqueadero, alojamiento y reabastecimiento de combustible. Atendiendo estas necesidades, Stop And Go surge como proyecto de inversión que pretende constituir un espacio eficazmente equipado, con altos estándares de calidad y de bajo costo. En el presente documento se desarrolla el plan de negocios y de viabilidad, recorriendo la estructura de la organización, las características de los servicios ofrecidos, la propuesta de mercadeo y la viabilidad estratégica y financiera.
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Ambient concentrations of trace elements with 2 h time resolution were measured in PM10–2.5, PM2.5–1.0 and PM1.0–0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3–6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6–3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10–2.5 mass fraction, roughly twice that of the PM1.0–0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4–5.4 for SW, 1.7–2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10–2.5 sea salt (factor of up to 2), which may be influenced by traffic-induced resuspension of sea and/or road salt. Heavy-duty vehicles appeared to have a larger effect than passenger vehicles on the concentrations of all elements influenced by resuspension (including sea salt) and wearing processes. Trace element concentrations in London were influenced by both local and regional sources, with coarse and intermediate fractions dominated by traffic-induced resuspension and wearing processes and fine particles influenced by regional transport.
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In the metropolitan area of Sao Paulo, Brazil, ozone and particulate matter ( PM) are the air pollutants that pose the greatest threat to air quality, since the PM and the ozone precursors ( nitrogen oxides and volatile organic compounds) are the main source of air pollution from vehicular emissions. Vehicular emissions can be measured inside road tunnels, and those measurements can provide information about emission factors of in-use vehicles. Emission factors are used to estimate vehicular emissions and are described as the amount of species emitted per vehicle distance driven or per volume of fuel consumed. This study presents emission factor data for fine particles, coarse particles, inhalable particulate matter and black carbon, as well as size distribution data for inhalable particulate matter, as measured in March and May of 2004, respectively, in the Janio Quadros and Maria Maluf road tunnels, both located in Sao Paulo. The Janio Quadros tunnel carries mainly light-duty vehicles, whereas the Maria Maluf tunnel carries light-duty and heavy-duty vehicles. In the Janio Quadros tunnel, the estimated light-duty vehicle emission factors for the trace elements copper and bromine were 261 and 220 mu g km(-1), respectively, and 16, 197, 127 and 92 mg km(-1), respectively, for black carbon, inhalable particulate matter, coarse particles and fine particles. The mean contribution of heavy-duty vehicles to the emissions of black carbon, inhalable particulate matter, coarse particles and fine particles was, respectively 29, 4, 6 and 6 times higher than that of light-duty vehicles. The inhalable particulate matter emission factor for heavy-duty vehicles was 1.2 times higher than that found during dynamometer testing. In general, the particle emissions in Sao Paulo tunnels are higher than those found in other cities of the world.
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During sugar cane harvesting season, which occurs from May to November of each year, the crops are burnt, cut, and transported to the mills. There are reports showing that mutagenic activity and PAH content increase during harvesting season in some areas of Sao Paulo State in comparison with nonharvesting periods. The objective of this work was to preliminarily characterize the mutagenic activity of the total organic extracts as well as corresponding organic fractions of airborne particulate matter (PM) collected twice from two cities, Araraquara (ARQ) and Piracicaba (PRB), during sugar cane harvesting season using the Salmonella/microsome microssuspension assay. One sample collected in Sao Paulo metropolitan area was also included. The mutagenicity of the total extracts ranged from 55 to 320 revertants per cubic meter without the addition of S9 and from not detected to 57 revertants per cubic meter in the presence of S9 in areas with sugar cane plantations. Of the three fractions analyzed, the most polar ones (nitro and oxy) were the most potent. A comparison of the response of TA98 with YG1041 and the increased potencies without S9 indicated that nitro compounds are causing the observed effect. More studies are necessary to verify the sources of the mutagenic activity such as burning of vegetal biomass and combustion of heavy duty vehicles used to transport the sugar cane to the mills. The Salmonella/microsome assay can be an important tool to monitor the atmosphere for mutagenicity during sugar cane harvesting season.
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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The intended purpose of this paper is to present the main aspects of natural gas applied to the public transportation as well as the environmental, economical and technical impacts in this sector. Also it is given specific information to be considered when comparing natural gas to other fuels, specially the diesel. At this point is presented the types of internal combustion engines (Otto and Diesel cycle) and which type is used in each vehicle. Moreover, it is presented the main standards pollutant emission (Euro, US and Proconve) with a brief explanation of the tests made in order to approve the engines. This paper is focused on heavy duty vehicles. Also in this paper is exposed the economic impact due to the natural gas use in the public transportation fleet. In addition is presented a real case (of Berlin) and an estimative to a Brazilian city, presenting the potential of natural gas as vehicular fuel in Brazil, as well as financial and environmental aspects of the substitution
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The intended purpose of this paper is to present the main aspects of natural gas applied to the public transportation as well as the environmental, economical and technical impacts in this sector. Also it is given specific information to be considered when comparing natural gas to other fuels, specially the diesel. At this point is presented the types of internal combustion engines (Otto and Diesel cycle) and which type is used in each vehicle. Moreover, it is presented the main standards pollutant emission (Euro, US and Proconve) with a brief explanation of the tests made in order to approve the engines. This paper is focused on heavy duty vehicles. Also in this paper is exposed the economic impact due to the natural gas use in the public transportation fleet. In addition is presented a real case (of Berlin) and an estimative to a Brazilian city, presenting the potential of natural gas as vehicular fuel in Brazil, as well as financial and environmental aspects of the substitution
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The main aim of this study was to evaluate the impact of the urban pollution plume from the city of Manaus by emissions from mobile and stationary sources in the atmospheric pollutants concentrations of the Amazon region, by using The Weather Research and Forecasting with Chemistry (WRF-Chem) model. The air pollutants analyzed were CO, NOx, SO2, O3, PM2.5, PM10 and VOCs. The model simulations have been configured with a grid spacing of 3 km, with 190 x and 136 y grid points in horizontal spacing, centered in the city of Manaus during the period of 17 and 18 of March 2014. The anthropogenic emissions inventories have gathered from mobile sources that were estimated the emissions of light and heavy-duty vehicles classes. In addition, the stationary sources have considered the thermal power plants by the type of energy sources used in the region as well as the emissions from the refinery located in Manaus. Various scenarios have been defined with numerical experiments that considered only emissions by biogenic, mobile and stationary sources, and replacement fuel from thermal power plant, along with a future scenario consisting with twice as much anthropogenic emissions. A qualitative assessment of simulation with base scenario has also been carried out, which represents the conditions of the region in its current state, where several statistical methods were used in order to compare the results of air pollutants and meteorological fields with observed ground-based data located in various points in the study grid. The qualitative analysis showed that the model represents satisfactorily the variables analyzed from the point of view of the adopted parameters. Regarding the simulations, defined from the base scenarios, the numerical experiments indicate relevant results such as: it was found that the stationary sources scenario, where the thermal power plants are predominant, resulted in the highest concentrations, for all air pollutants evaluated, except for carbon monoxide when compared to the vehicle emissions scenario; The replacement of the energy matrix of current thermal power plants for natural gas have showed significant reductions in pollutants analyzed, for instance, 63% reductions of NOx in the contribution of average concentration in the study grid; A significant increase in the concentrations of chemical species was observed in a futuristic scenario, reaching up to a 81% increase in peak concentrations of SO2 in the study area. The spatial distributions of the scenarios have showed that the air pollution plume from Manaus is predominantly west and southwest, where it can reach hundreds of kilometers to areas dominated by original soil covering.
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Diesel trucks and buses account for approximately 50 percent of the particulate matter (PM) and oxides of nitrogen (NOx) air pollution from on-road vehicles in Illinois. PM and NOx may contribute to a variety of health effects, including nausea, headaches, increased risk of asthma attacks, lung cancer, and premature death. Children and people with lung and heart conditions, are generally the most sensitive to diesel exhaust. Millions of tons of air pollution are emitted every year in the U.S. by trucks and buses that idle while parked.
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Dissertação de mestrado em Engenharia Mecânica