Spelling suggestions: "subject:"ehicle emissions"" "subject:"aehicle emissions""
11 |
Activation of epithelial signal transduction pathways, cytokine production and airway inflammation following diesel exhaust exposure /Pourazar, Jamshid, January 2006 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 5 uppsatser.
|
12 |
Particularly harmful particles? : a study of airborne particles with a focus on genotoxicity and oxidative stress /Karlsson, Hanna, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 6 uppsatser.
|
13 |
Effect of diesel exhaust particles on allergic reactions and airway responsiveness in ovalbumin-sensitized brown Norway ratsDong, Caroline. January 2007 (has links)
Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xi, 118 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-118).
|
14 |
Unconventional Monetary Policy in a Modern Paradigm of Money and Two Other EssaysJanuary 2017 (has links)
abstract: This dissertation contains a portfolio of papers in economics. The first paper, ``Vehicle Emissions Inspection Programs: Equality and Impact," presents the results of a study of the Arizona Vehicle Emissions Inspection Program. Using a unique data set, I find that the Arizona Vehicle Emissions Inspection Program is regressive in that it constrains the vehicle repair decisions of people on the low end of the income distribution more than those on the high end. I also find that the social cost of the program in Arizona is more than twice the social benefit, assuming a \$7 million value of statistical life. The second paper is ``Fiat Value in the Theory of Value." Because of advances in information processing technology, it is now technically feasible to have a currency-less monetary system. This paper explores one such system. In the model, prices are in units currency-less fiat money called fiat value, fiat value is a form of government debt, and the services of the stock of fiat value are a factor of production. In this system, the National accounts must be revised to account for money as a production factor, Friedman satiation is possible even with positive inflation, and various monetary policy regimes are explored. The third paper, ``Unconventional Monetary Policy in a Modern Paradigm of Money," uses the model developed in ``Fiat Value in the Theory of Value" to evaluate quantitative easing and interest on reserves policies as a response to liquidity shocks. I find that quantitative easing is an effective response to liquidity crises because it drives the marginal product of money to zero. When the marginal product of money is zero, the business sector does not have to pay to rent the services of money, a production factor that is free to create. I also show that a positive interest on reserve policy hampers the effectiveness of quantitative easing, and that quantitative easing does not cause a high inflation rate. / Dissertation/Thesis / Doctoral Dissertation Economics 2017
|
15 |
Efeito das diferentes frações do material particulado proveniente da emissão de motores movidos a óleo diesel sobre o epitélio do palato da rã / Effects of different fractions from diesel engines exhaust particles on the frog ciliated epitheliumSergio Henrique Kiemle Trindade 30 March 2011 (has links)
INTRODUÇÃO: A poluição atmosférica é reconhecida como fonte de possíveis agravos à saúde. Estudos tem demonstrado uma clara associação entre aumento da concentração dos poluentes atmosféricos, especialmente o material particulado proveniente de resíduos de exaustão de motores movidos a diesel, com morbidade e mortalidade respiratória e cardíaca na população geral. Até o presente momento, sabe-se que o material particulado possui ações deletérias sobre as vias aéreas superiores e inferiores; contudo, ainda não são completamente conhecidas as ações tóxicas isoladas das diferentes frações do material particulado do diesel. OBJETIVO: O presente estudo teve por finalidade avaliar o grau de toxicidade das frações orgânicas de baixa, média e alta polaridade e da fração inorgânica do material particulado proveniente da emissão de motores movidos a óleo diesel sobre o epitélio mucociliar. MÉTODOS: Para tanto, utilizou-se como modelo experimental a preparação do palato da rã, que possui um epitélio similar ao das vias aéreas de mamíferos. O estudo foi dividido em duas etapas: Fase I - Quarenta palatos foram utilizados com intuito de titular a concentração de material particulado bruto capaz de promover um aumento significante no tempo relativo de transporte mucociliar. Fase II - Uma vez definida a concentração efetiva, cinqüenta palatos foram expostos aos seguintes tratamentos: material particulado bruto do diesel (sem nenhum tipo de tratamento), material particulado do diesel tratado com hexano (solvente que reduz a quantidade dos compostos orgânicos de baixa polaridade), material particulado do diesel tratado metanol (solvente que reduz a quantidade de compostos orgânicos de polaridade intermediária, gerando aumento relativo da concentração de orgânicos de baixa e alta polaridade) e material particulado do diesel tratado ácido nítrico (solvente que reduz a concentração de compostos inorgânicos, gerando aumento relativo da fração orgânica como um todo). Para fins de controle utilizou-se um grupo com ringer-rã. As variáveis analisadas foram: tempo relativo de transporte mucociliar, freqüência de batimento ciliar e análise histológica, na qual foram avaliados o volume proporcional de muco ácido, muco neutro, muco misto, de cílios, vacúolos, dos núcleos celulares e interstício e espessura epitelial. RESULTADOS: Fase I: A concentração de material particulado bruto capaz de promover um aumento significativo no tempo relativo de transporte mucociliar, e também do volume proporcional de muco ácido (p<0,05), correspondeu a 12mg/L. Fase II: Observou-se: a) aumento significativo no tempo relativo de transporte mucociliar e redução significativa do volume proporcional de muco neutro no grupo ácido nítrico; b) maior volume proporcional de muco ácido no grupo metanol (p<0,05); c) ausência de diferenças entre o grupo controle e o grupo hexano, tanto na análise histológica quanto no tempo relativo de transporte mucociliar. CONCLUSÃO: Os dados obtidos sugerem que os compostos orgânicos de baixa polaridade do material particulado proveniente da emissão de motores movidos a óleo diesel desempenham um importante papel na toxicidade aguda ao epitélio ciliado / INTRODUCTION: Air pollution is recognized as a source of potential health problems. Studies have shown a clear association between increasing concentration of atmospheric pollutants, especially particulate matter from waste exhaust of diesel engines, and respiratory and cardiac morbidity and mortality in the general population. To date, it is well known that particulate matter from diesel exhaust has deleterious actions on upper and lower airways; however, the isolated toxic actions of different fractions of the particulate matter are not yet fully understood. OBJECTIVE: This study aimed at evaluating the degree of toxicity of the organic fractions of low, intermediate and high polarity and of the inorganic fraction of particulate matter from diesel engines on the ciliated epithelium. METHODS: The experimental model used was the frog palate preparation, which has a similar epithelium to that found in mammalian airways. The study was divided into two phases: Phase I - Forty palates were used in order to titrate the concentration of intact diesel particulate matter able to elicit a significant increase in the relative time of mucociliary transport. Phase II Once defined the optimal concentration, fifty palates were exposed to dilutions with the following treatments: intact diesel particulate material (without any treatment), particulate matter from diesel exhaust treated with hexane (solvent which reduces the amount of organic compounds of low polarity), particulate matter from diesel exhaust treated with methanol (solvent which reduces the amount of organic compounds with intermediate polarity, generating a relative increase in concentration of organic compounds with low and high polarity) and particulate matter from diesel exhaust treated with nitric acid (solvent which removes inorganic compounds, eliciting a relative increase of the organic fraction as a whole). For control purposes, a group of frog-ringer was used. The following variables were analyzed: relative time of mucociliary transport, ciliary beating frequency and histological analysis, which evaluated proportional volume of acid mucus, neutral and mixed mucus, cilia, vacuoles, cell nuclei and interstice, and epithelial thickness. RESULTS: Phase I: The effective concentration of intact diesel particulate matter in eliciting a significant increase in the relative time of mucociliary transport, and a proportional increase of acid mucus volume (p<0.05), corresponded to 12mg/L. Phase II: a) The nitric acid treatment caused a significant increase in the relative time of mucociliary transport, and decrease in the proportional volume of neutral mucus. b) A higher proportional volume of acid mucus was found in the methanol group (p<0.05). c) There were no differences between control and hexane groups regarding histological findings and relative time of mucociliary transport. CONCLUSION: The results suggest that organic compounds of low polarity from diesel engines exhaust particles play an important role in the acute toxicity on the ciliated epithelium
|
16 |
Characterization of Air Pollutant and Greenhouse Gas Emissions from Energy Use and Energy Production Processes in United StatesLi, Xiang 01 September 2017 (has links)
Air pollutants and greenhouse gases are two groups of important trace components in the earth’s atmosphere that can affect local air quality, be detrimental to the human health and ecosystem, and cause climate change. Human activities, especially the energy use and energy production processes, are responsible for a significant share of air pollutants and greenhouse gases in the atmosphere. In this work, I specifically focused on characterizing air pollutants and greenhouse gas emissions from the on-road gasoline and diesel vehicles, which is an important energy use process that largely contributes to the urban air pollutions, and from the natural gas production systems, which is a major energy production process that has increased dramatically in recent years and is expected to have a long-lasting impact in the future. We conducted multi-seasonal measurements in the Fort Pitt Tunnel in Pittsburgh, PA to update the on-road vehicle emission factors, to measure the size distribution of vehicle emitted particulate matter (PM), and to quantify the volatility distributions of the vehicle emitter primary organic aerosol (POA). We also conducted mobile measurements in the Denver-Julesburg Basin, the Uintah Basin, and the Marcellus Shale to quantify facility-level VOC emission from natural gas production facilities, and I constructed a gridded (0.1° × 0.1°) methane emission inventory of natural gas production and distribution over the contiguous US. I found that the stricter emission standards were effective on regulating NOx and PM emissions of diesel vehicles and the NOx, CO and organic carbon (OC) emissions of gasoline vehicles, while the elemental carbon (EC) emissions of gasoline vehicles did not change too much over the past three decades. Vehicle-emitted particles may be largely externally mixed, and a large fraction of vehicle-emitted particles may be purely composed of volatile component. Vehicle-emitted smaller particles (10– 60 nm) are dominantly (over 75%) composed of volatile component. The size-resolved particles and particles emission factors for both gasoline and diesel vehicles are also reported in this work. I also found that the POA volatility distribution measured in the dynamometer studies can be applied to describe gas-particle partitioning of ambient POA emissions. The POA volatility distribution measured in the tunnel does not have significant diurnal or seasonal variations, which indicate that a single volatility distribution is adequate to describe the gas-particle partitioning of vehicle emitted POA in the urban environment. The facility-level VOC emission rates measured at gas production facilities in all three gas production fields are highly variable and cross a range of ~2-3 order of magnitudes. It suggests that a single VOC emission profile may not be able to characterize VOC emissions from all natural gas production facilities. My gridded methane emission inventory over the contiguous US show higher methane emissions over major natural gas production fields compared with the Environmental Protection Agency Inventory of US Greenhouse Gas Emission and Sinks (EPA GHGI) and the Emission Database for Global Atmospheric Research, version 4.2 (Edgar v4.2). The total methane emissions of the natural gas production and distribution sector estimated by my inventory are 74% and 20% higher than the Edgar v4.2 and EPA GHGI, respectively. I also run the GEOS-Chem methane simulation with my inventory and EPA GHGI and compare with the GOSAT satellite data, and results show that my inventory can improve the model and satellite comparison, but the improvement is very limited. The size-resolved emission factors of vehicle emitted particles and POA volatility distribution reported in this work can be applied by the chemical transport models to better quantify the contribution of vehicle emissions to the PM in the atmosphere. Since our measurement of VOC emissions of natural gas production facilities were conducted before EPA started to regulate VOC emissions from the O&NG production facilities in 2016, the facility-level VOC emission rates reported in this work can serve as the basis for future studies to test the effectiveness of the regulatory policies. The spatially resolved methane emission inventory of natural gas production and distribution constructed in this work can be applied to update the current default methane emission inventory of GEOS-Chem, and the updated methane emission inventory can be used as a better a priori emission field for top-down studies that inversely estimate methane emissions from atmospheric methane observation.
|
17 |
Investigation of Probable Pollution from Automobile Exhaust Gases in Kampala City, Uganda : To Assess the current automobile exhaust gas emission levels and characterize the emissions from different automobile typesBateebe, Irene January 2011 (has links)
It is estimated that transport sources in developing countries contribute about 4% of the global fossil carbon dioxide versus 18% by industrialized countries. The cost of urban air pollution is estimated to be 2% of GDP in developed countries and more than 5% in developing countries. With an annual vehicle registration growth of over 30% in 2008 and a population growth rate of 6%, the number of automobiles in Kampala city of Uganda is expected to continue growing exponentially. Most of the vehicles used are imported into the country when quite old with worn out engines and low energy efficiencies. As a result, such vehicles profusely emit exhaust gases which may be harmful to both human health and the environment. Controlling pollution from the transport sector is vital to improving the quality of air and protecting public health. The objective of this dissertation was to determine the level of pollution from automobile exhaust gases in Kampala City and its impacts on human health and the environment. The study involved the analysis of tail pipe emissions using a gas analyser. It covered mini buses, motorcycles and personal vehicles which constitute 92% of the Kampala vehicle parc. It was established that the main types of exhaust gases from the automobiles were CO2, NOx, CO, NO and HC. The findings estimated the highest level of NOx tail pipe emissions at 0.15 mg/m3, HC emissions at 2.59 mg/m3, CO at 110 mg/m3 and 286.6 mg/m3 for CO2. The reported ambient air emissions were estimated at 0.18 ppm, 14000 ppm and 1.3 ppm corresponding to NO2, CO2 and CO, respectively. The study further investigated the impact of four mitigation methods on emission levels using the LEAP model. The impact of increasing penetration of city buses, introduction of tail pipe emission standards and hybrid cars and improvement of vehicle fuel economy were investigated. It was found that if left unabated, the emissions will continue to grow with the increasing number of motor vehicles. Implementation of the proposed mitigation methods resulted in a reduction in the GWP reduced by 52%, 51%, 17% and 8.5%, respectively. It is recommended that a comprehensive motor vehicle pollution control program be designed to implement the proposed NEMA vehicle emission standards. Establishment of an integrated transport system promoting the growth in number of city buses should be made a priority to reduce on emission levels and enable the decongestion of Kampala city.
|
18 |
Assessing Different Freeway Interchange Design Impacts On Traffic Emission And Fuel Consumption Through Microsimulation.Samandi, Fayezeh 18 May 2021 (has links)
No description available.
|
19 |
VERTUS: VEHICLE EMISSIONS RELATED TO URBAN SPRAWLDolney, Timothy J. 29 June 2007 (has links)
No description available.
|
20 |
Emissões veiculares em São Paulo: quantificação de fontes com modelos receptores e caracterização do material carbonáceo / Vehicle emissions in São Paulo: quantification of sources with receptor models and characterization of carbonaceous matterSantos Junior, Djacinto Aparecido Monteiro dos 12 May 2015 (has links)
A significativa emissão veicular na Região Metropolitana de São Paulo (RMSP), com mais de 7 milhões de veículos e uma população da ordem de 18 milhões de habitantes, fazem desta uma área crítica do ponto de vista de níveis de poluentes atmosféricos. Neste trabalho foi obtida a determinação quantitativa de fontes de poluentes atmosféricos na RMSP, em particular do material carbonáceo na fração fina (PM2.5) do aerossol atmosférico, focando na componente veicular. Como parte do projeto FONTES, coordenado pela Petrobrás, PUC-Rio e IFUSP, foram operadas por 1 ano quatro estações de amostragem localizadas em Congonhas (CGH), Ibirapuera (IBP), Cerqueira César (FSP) e Instituto de Física da USP (IFP), no período entre agosto de 2011 e janeiro de 2014. A concentração em massa de material particulado fino (PM2.5), grosso (PM2.5-10), e inalável (PM10) foi determinada através de análise gravimétrica. Íons solúveis foram determinados por cromatografia iônica (IC), elementos traços por fluorescência de raios-X (XRF) e as concentrações de black carbon equivalente por refletância ótica. As componentes de carbono orgânico (OC) e carbono elementar (EC), bem como as diversas frações carbonáceas foram determinadas por análises termo-ópticas em equipamento da Sunset Inc., seguindo vários protocolos analíticos. As concentrações de gases tais como CO, NOx, e O3 foram fornecidas por estações de monitoramento da CETESB. Modelos receptores tais como APFA (Absolute Principal Factor Analysis) foram usados na determinação quantitativa de fontes de poluentes. Observou-se uma grande similaridade nas concentrações medidas nas estações, indicando uma homogeneidade nas concentrações e composição de aerossóis da moda fina (PM2.5) na RMSP. Nas estações amostradoras IFP, FSP e IBP foram observadas concentrações entre 10 e 12g m-3 na fração fina e na faixa de 16 a 18 g m-3 na fração grossa. Em CGH, observou-se uma concentração média de 34 g m-3, para PM10. O balanço químico de massa mostrou, na fração fina, impacto predominante de aerossóis orgânicos (~50%), EC (~20%) e sulfato (~20%). Na fração grossa verificaram-se concentrações dominantes de aerossóis de poeira do solo (~40%). A APFA identificou e quantificou o impacto das componentes veicular (~60%), ressuspensão de solo (~10%), emissões industriais e de sulfato (~20%), aerossol marinho (~5%) e aerossol secundário (~5%). O impacto da componente veicular é dominante na RMSP. A aplicação dos modelos receptores forneceu a caracterização do material carbonáceo de acordo com as fontes de emissões e um perfil de volatilidade do material carbonáceo. / The large vehicle fleet in the Metropolitan Region of São Paulo (RMSP), with more than 7 million vehicles and a population of about 18 million people, make this a critical area from the point of view of atmospheric pollutants levels. This work focused on the quantitative determination of air pollutant sources, focusing at the vehicular component and the carbonaceous material in the fine fraction (PM2.5) of the atmospheric aerosol of RMSP. As part of the FONTES research project, coordinated by Petrobrás, PUC-Rio and IFUSP, it was operated for 1 year four sampling stations located in Congonhas (CGH), Ibirapuera (IBP), Cerqueira César (FSP) and the Institute of Physics at USP (IFP) during the period from August 2011 to January 2014. The mass concentrations of fine (PM2.5), coarse (PM2.5-10) and inhalable (PM10) particulate matter was determined by gravimetric analysis. Soluble ions were determined by ion chromatography (IC), trace elements by X-ray fluorescence (XRF) and equivalent black carbon (EBC) concentration by optical reflectance. The organic carbon (OC) and elemental carbon (EC) components, as well as several carbonaceous fractions were determined by thermo-optical analysis using a Sunset Inc. equipment, following various analytical protocols. The concentration of gases such as CO, NOx, and O3 were obtained from CETESB air pollution monitoring stations. Receptors models such APFA (Absolute Principal Factor Analysis) were used for the quantification of the impacts of polluting sources. It was observed similar concentrations in the several sampling stations, showing uniformity in the concentrations and aerosol composition of PM2.5 in the RMSP. For the sites IFP, FSP and IBP were observed concentrations between 10 and 12 g m-3 in the fine fraction and in the range from 16 to 18 g m-3 in the coarse fraction. In the CGH site, there was an average concentration of 34 g m-3 of PM10. The chemical mass balance showed large presence of organic aerosols (~50%), EC (~20%) and sulfate (~20%) in the fine mode fraction. In the coarse fraction soil dust aerosols (~40%) dominates. The APFA identified and quantified the impact of vehicular components (~60%), soil dust (~10%), industrial emissions and sulfate (~20%), marine aerosol (~5%) and secondary aerosol (~5%). Vehicular emissions is the major air pollution component at the RMSP. The application of receptor models has provided the source characterization of carbonaceous material according to their volatility profile.
|
Page generated in 0.0924 seconds