Thesis (Ph. D.)--University of Sydney, 2008. / Includes tables. Includes list of publications: p. 9. Title from title screen (viewed September 19, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Chemical and Biomolecular Engineering, Faculty of Engineering and Information Technologies. Includes bibliographical references. Also available in print form.

Thesis (PH.D.) -- Syracuse University, 2004. / "Publication number AAT 3160395."

Thesis (Ph. D.)--Syracuse University, 2005. / "Publication number AAT 3193849."

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3963. Adviser: Christopher P. L. Barkan. Includes bibliographical references (leaves 266-275) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 4029. Advisers: Vernon Snoeyink; Benito Marinas. Includes bibliographical references (leaves 100-105) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6268. Adviser: Praveen Kumar. Includes bibliographical references (leaves 172-183) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6653. Adviser: Barbara Minsker. Includes bibliographical references (leaves 161-170) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6654. Adviser: Charles J. Werth. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

This dissertation presents an innovative methodology in the form of two papers for the feasibility assessment and optimization of Vacuum Enhanced Recovery (VER) to remediate non aqueous phase liquids (NAPLs) in the vadose zone. The first paper demonstrates the use of a pilot-scale two-dimensional laboratory soil cell and an automated dual-energy gamma ray attenuation system for the feasibility assessment of VER to remediate free-product NAPL spills. The investigations were conducted in a 1.5 x 1 x 0.08 meter cell filled with heterogeneous soils for the simultaneous and continuous measurement of NAPL and water saturations at 96 programmed locations. The dynamic laboratory method determines the spatial distributions of three-phase fluid saturations of an oil spill simulation from the surface as it migrates through the vadose zone during the sequential stages of infiltration, redistribution and VER. Contour plots of observed NAPL and water saturations identify the distribution of NAPL as entrapped liquid in heterogeneous soils unavailable for free-product recovery by VER. The accuracy of the methodology used for the measurement of NAPL retention in soil was illustrated by a NAPL retention measurement precision analysis. A mean difference of 0.97% was achieved by comparing gamma system measured NAPL retention volumes in the soil with that derived by the VER system. The second paper utilizes the pilot-scale laboratory results for a comparative analysis with model simulations to calibrate a three-phase model and optimize the design of VER systems for free-product NAPL remediation in heterogeneous soils.

<p> Low-cost air quality sensor systems have the potential to provide entirely new information about our air quality given (1) the increase in temporal and spatial resolution that they facilitate, (2) their capacity to utilize many different sensor types in a single system, and (3) their accessibility that enables citizens to measure air quality for themselves. However, there are still many challenges associated with sensor use, including issues of sensor performance quantification and a need for best practices to guide the use of this technology, particularly for community-based research. This thesis addresses these challenges. This thesis includes the quantification of volatile organic compound using sensors to provide methane and non-methane hydrocarbon concentration estimates in complex environments. To support the development of best practices, multiple deployments allowed for the exploration of questions related to the influence the building-scale variability of pollutants on sensor system siting, choices in sensor data processing, and field calibration procedures. Additionally, education and outreach work utilizing sensors and involving partnerships with local communities are described with the focus on resources and lessons that could support future community-based air quality research. </p><p> This thesis also demonstrated the potential for sensor data. For example, sensor estimates of methane levels from a network deployed in rural Colorado revealed trends similar to those noted by other researchers using high-quality instrumentation and methods. In another example, sensor estimates of methane and total non-methane hydrocarbons levels, analyzed along with other sensor signals (i.e., from carbon monoxide and carbon dioxide sensors), helped to identify distinct pollutant sources on a fine temporal and spatial scale in a South Los Angeles neighborhood. The results and conclusions of this work support the continued development of this technology with the goal of collecting preliminary and supplementary information that may contribute to improved public and environmental health.</p><p>