Page 1 |
Save page Remove page | Previous | 1 of 236 | Next |
|
small (250x250 max)
medium (500x500 max)
large ( > 500x500)
Full Resolution
All (PDF)
|
This page
All
Subset |
INVESTIGATION OF PHYSICO-CHEMICAL CHARACTERISTICS OF
PARTICULATE MATTER FROM VEHICULAR SOURCES
by
Subhasis Biswas
____________________________________________________________________
A Dissertation Presented to the
FACULTY OF THE GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(ENVIRONMENTAL ENGINEERING)
May 2008
Copyright 2008 Subhasis Biswas
Object Description
| Title | Investigation of physico-chemical characteristics of particulate matter from vehicular sources |
| Author | Biswas, Subhasis |
| Author email | subhasib@usc.edu |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Civil Engineering (Environmental Engineering) |
| School | Viterbi School of Engineering |
| Date defended/completed | 2008-02-19 |
| Date submitted | 2008 |
| Restricted until | Unrestricted |
| Date published | 2008-02-26 |
| Advisor (committee chair) | Sioutas, Constantinos |
| Advisor (committee member) |
Henry, Ronald C. Phares, Denis J. |
| Abstract | Particles from vehicular sources have drawn public attention for their potential to cause health risks. Beside chemical composition of these particles, their physical attributes are considered to be critical in eliciting adverse health outcomes. This thesis provides valuable information on particle physico-chemical properties with special focus on physical parameters such as size distribution, volatility, effective density, fractal dimension, surface area etc. Particle effective density and fractal dimensions were measured near a gasoline and a mixed freeway with significant diesel fleet. Diesel vehicles emit higher fraction of low density chain agglomerates compared to gasoline vehicles. Particle density at a receptor site showed interesting diurnal trend with peaks during sunny afternoons. Overall, particles demonstrated an inverse relation between size and density. Particle volatility, an important parameter to infer exposure to commuters, was measured near a pure gasoline and diesel dominated mixed-traffic freeway. Diesel particulates were associated with higher content of non-volatiles than those generated from gasoline engines and correlated excellently with the refractory elemental carbon emissions. Particle mixing characteristics not only depend on the fleet composition but also on environmental factors. Thus, to investigate the effect of meteorological conditions on particle characteristics experimental campaigns were designed to capture seasonal and diurnal variability. Although the daytime seasonal influences on particle volatility were minimal, strong diurnal changes were observed during winter.; Finally, the physical characteristics of particles from diesel vehicles retrofitted with advanced emission control technologies were determined by controlled studies with a dynamomter set-up. These after treatment devices were efficient in removing solid particles, but were less effective in controlling volatile species which formed fresh nucleation mode particles. Particle volatility, density, surface diameter and extent of agglomeration were determined and compared with respect to a baseline vehicle. Our results indicate that vehicles with strong nucleation mode particles are associated with higher volatility and density and lower agglomeration. |
| Keyword | particle; vehicle; physical; chemical |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Type | texts |
| Legacy record ID | usctheses-m1028 |
| Rights | Biswas, Subhasis |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | http://www.usc.edu/isd/libraries/services/ask_a_librarian/email/ |
| Filename | etd-Biswas-20080226 |
| Archival file | uscthesesreloadpub_Volume40/etd-Biswas-20080226.pdf |
Description
| Title | Page 1 |
| Full text | INVESTIGATION OF PHYSICO-CHEMICAL CHARACTERISTICS OF PARTICULATE MATTER FROM VEHICULAR SOURCES by Subhasis Biswas ____________________________________________________________________ A Dissertation Presented to the FACULTY OF THE GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (ENVIRONMENTAL ENGINEERING) May 2008 Copyright 2008 Subhasis Biswas |
Comments
Post a Comment for Page 1
