ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Creators: Doupe, Adam
- Creators: Abbaszadegan, Morteza
Description
The National Research Council 2011 report lists quantifying the extent of de facto (or unplanned) potable reuse in the U.S. as the top research need associated with assessing the potential for expanding the nations water supply through reuse of municipal wastewater. Efforts to identify the significance and potential health impacts of de facto water reuse are impeded by out dated information regarding the contribution of municipal wastewater effluent to potable water supplies. This project aims to answer this research need. The overall goal of the this project is to quantify the extent of de facto reuse by developing a model that estimates the amount of wastewater effluent that is present within drinking water treatment plants; and to use the model in conjunction with a survey to help assess public perceptions. The four-step approach to accomplish this goal includes: (1) creating a GIS-based model coupled with Python programming; (2) validating the model with field studies by analyzing sucralose as a wastewater tracer; (3) estimating the percentage of wastewater in raw drinking water sources under varying streamflow conditions; (4) and assessing through a social survey the perceptions of the general public relating to acceptance and occurrence of de facto reuse. The resulting De Facto Reuse in our Nations Consumable Supply (DRINCS) Model, estimates that treated municipal wastewater is present at nearly 50% of drinking water treatment plant intake sites serving greater than 10,000 people (N=2,056). Contrary to the high frequency of occurrence, the magnitude of occurrence is relatively low with 50% of impacted intakes yielding less than 1% de facto reuse under average streamflow conditions. Model estimates increase under low flow conditions (modeled by Q95), in several cases treated wastewater makes up 100% of the water supply. De facto reuse occurs at levels that surpass what is publically perceived in the three cities of Atlanta, GA, Philadelphia, PA, and Phoenix, AZ. Respondents with knowledge of de facto reuse occurrence are 10 times more likely to have a high acceptance (greater than 75%) of treated wastewater at their home tap.
ContributorsRice, Jacelyn (Author) / Westerhoff, Paul (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Vivoni, Enrique (Committee member) / Wutich, Amber (Committee member) / Arizona State University (Publisher)
Created2014
Description
Bacteria of the Legionella genus are a water-borne pathogen of increasing concern due to being responsible for more annual drinking water related disease outbreaks in the United States than all other microbes combined. Unfortunately, the development of public health policies concerning Legionella has impeded by several key factors, including a paucity of data on their interactions and growth requirements in water distribution networks, a poor understanding of potential transmission sources for legionellosis, and limitations in current methodology for the characterization of these pathogens. To address these issues, a variety of research approaches were taken. By measuring Legionella survival in tap water, association in pipe material biofilms, population dynamics in a model distribution system, and occurrence in drinking water distribution system biofilms, key aspects of Legionella ecology in drinking water systems were revealed. Through a series of experiments qualitatively and quantitatively examining the growth of Legionella via nutrients obtained from several water sources, environmental nutritional requirements and capability for growth in the absence of host organisms were demonstrated. An examination of automobile windshield washer fluid as a possible source of legionellosis transmission revealed Legionella survival in certain windshield washer fluids, growth within washer fluid reservoirs, high levels and frequency of contamination in washer fluid reservoirs, and the presence of viable cells in washer fluid spray, suggesting the potential for exposure to Legionella from this novel source. After performing a systematic and quantitative analysis of methodology optimization for the analysis of Legionella cells via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, several strains of this microbe isolated from separated and varied environmental water sampling sites were distinctly typed, demonstrating a potential application of this technology for the characterization of Legionella. The results from this study provide novel insight and methodology relevant to the development of programs for the monitoring and treatment of Legionella in drinking water systems.
ContributorsSchwake, David Otto (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Stout, Valerie (Committee member) / Arizona State University (Publisher)
Created2014
Description
With the increasing user demand for low latency, elastic provisioning of computing resources coupled with ubiquitous and on-demand access to real-time data, cloud computing has emerged as a popular computing paradigm to meet growing user demands. However, with the introduction and rising use of wear- able technology and evolving uses of smart-phones, the concept of Internet of Things (IoT) has become a prevailing notion in the currently growing technology industry. Cisco Inc. has projected a data creation of approximately 403 Zetabytes (ZB) by 2018. The combination of bringing benign devices and connecting them to the web has resulted in exploding service and data aggregation requirements, thus requiring a new and innovative computing platform. This platform should have the capability to provide robust real-time data analytics and resource provisioning to clients, such as IoT users, on-demand. Such a computation model would need to function at the edge-of-the-network, forming a bridge between the large cloud data centers and the distributed connected devices.
This research expands on the notion of bringing computational power to the edge- of-the-network, and then integrating it with the cloud computing paradigm whilst providing services to diverse IoT-based applications. This expansion is achieved through the establishment of a new computing model that serves as a platform for IoT-based devices to communicate with services in real-time. We name this paradigm as Gateway-Oriented Reconfigurable Ecosystem (GORE) computing. Finally, this thesis proposes and discusses the development of a policy management framework for accommodating our proposed computational paradigm. The policy framework is designed to serve both the hosted applications and the GORE paradigm by enabling them to function more efficiently. The goal of the framework is to ensure uninterrupted communication and service delivery between users and their applications.
This research expands on the notion of bringing computational power to the edge- of-the-network, and then integrating it with the cloud computing paradigm whilst providing services to diverse IoT-based applications. This expansion is achieved through the establishment of a new computing model that serves as a platform for IoT-based devices to communicate with services in real-time. We name this paradigm as Gateway-Oriented Reconfigurable Ecosystem (GORE) computing. Finally, this thesis proposes and discusses the development of a policy management framework for accommodating our proposed computational paradigm. The policy framework is designed to serve both the hosted applications and the GORE paradigm by enabling them to function more efficiently. The goal of the framework is to ensure uninterrupted communication and service delivery between users and their applications.
ContributorsDsouza, Clinton (Author) / Ahn, Gail-Joon (Thesis advisor) / Doupe, Adam (Committee member) / Dasgupta, Partha (Committee member) / Arizona State University (Publisher)
Created2015
Description
Android is currently the most widely used mobile operating system. The permission model in Android governs the resource access privileges of applications. The permission model however is amenable to various attacks, including re-delegation attacks, background snooping attacks and disclosure of private information. This thesis is aimed at understanding, analyzing and performing forensics on application behavior. This research sheds light on several security aspects, including the use of inter-process communications (IPC) to perform permission re-delegation attacks.
Android permission system is more of app-driven rather than user controlled, which means it is the applications that specify their permission requirement and the only thing which the user can do is choose not to install a particular application based on the requirements. Given the all or nothing choice, users succumb to pressures and needs to accept permissions requested. This thesis proposes a couple of ways for providing the users finer grained control of application privileges. The same methods can be used to evade the Permission Re-delegation attack.
This thesis also proposes and implements a novel methodology in Android that can be used to control the access privileges of an Android application, taking into consideration the context of the running application. This application-context based permission usage is further used to analyze a set of sample applications. We found the evidence of applications spoofing or divulging user sensitive information such as location information, contact information, phone id and numbers, in the background. Such activities can be used to track users for a variety of privacy-intrusive purposes. We have developed implementations that minimize several forms of privacy leaks that are routinely done by stock applications.
Android permission system is more of app-driven rather than user controlled, which means it is the applications that specify their permission requirement and the only thing which the user can do is choose not to install a particular application based on the requirements. Given the all or nothing choice, users succumb to pressures and needs to accept permissions requested. This thesis proposes a couple of ways for providing the users finer grained control of application privileges. The same methods can be used to evade the Permission Re-delegation attack.
This thesis also proposes and implements a novel methodology in Android that can be used to control the access privileges of an Android application, taking into consideration the context of the running application. This application-context based permission usage is further used to analyze a set of sample applications. We found the evidence of applications spoofing or divulging user sensitive information such as location information, contact information, phone id and numbers, in the background. Such activities can be used to track users for a variety of privacy-intrusive purposes. We have developed implementations that minimize several forms of privacy leaks that are routinely done by stock applications.
ContributorsGollapudi, Narasimha Aditya (Author) / Dasgupta, Partha (Thesis advisor) / Xue, Guoliang (Committee member) / Doupe, Adam (Committee member) / Arizona State University (Publisher)
Created2014
Description
The increasing number of continually connected mobile persons has created an environment conducive to real time user data gathering for many uses both public and private in nature. Publicly, one can envision no longer requiring a census to determine the demographic composition of the country and its sub regions. The information provided is vastly more up to date than that of a census and allows civil authorities to be more agile and preemptive with planning. Privately, advertisers take advantage of a persons stated opinions, demographics, and contextual (where and when) information in order to formulate and present pertinent offers.
Regardless of its use this information can be sensitive in nature and should therefore be under the control of the user. Currently, a user has little say in the manner that their information is processed once it has been released. An ad-hoc approach is currently in use, where the location based service providers each maintain their own policy over personal information usage.
In order to allow more user control over their personal information while still providing for targeted advertising, a systematic approach to the release of the information is needed. It is for that reason we propose a User-Centric Context Aware Spatiotemporal Anonymization framework. At its core the framework will unify the current spatiotemporal anonymization with that of traditional anonymization so that user specified anonymization requirement is met or exceeded while allowing for more demographic information to be released.
Regardless of its use this information can be sensitive in nature and should therefore be under the control of the user. Currently, a user has little say in the manner that their information is processed once it has been released. An ad-hoc approach is currently in use, where the location based service providers each maintain their own policy over personal information usage.
In order to allow more user control over their personal information while still providing for targeted advertising, a systematic approach to the release of the information is needed. It is for that reason we propose a User-Centric Context Aware Spatiotemporal Anonymization framework. At its core the framework will unify the current spatiotemporal anonymization with that of traditional anonymization so that user specified anonymization requirement is met or exceeded while allowing for more demographic information to be released.
ContributorsSanchez, Michael Andrew (Author) / Ahn, Gail-Joon (Thesis advisor) / Doupe, Adam (Committee member) / Dasgupta, Partha (Committee member) / Arizona State University (Publisher)
Created2014
Description
The rate at which new malicious software (Malware) is created is consistently increasing each year. These new malwares are designed to bypass the current anti-virus countermeasures employed to protect computer systems. Security Analysts must understand the nature and intent of the malware sample in order to protect computer systems from these attacks. The large number of new malware samples received daily by computer security companies require Security Analysts to quickly determine the type, threat, and countermeasure for newly identied samples. Our approach provides for a visualization tool to assist the Security Analyst in these tasks that allows the Analyst to visually identify relationships between malware samples.
This approach consists of three steps. First, the received samples are processed by a sandbox environment to perform a dynamic behavior analysis. Second, the reports of the dynamic behavior analysis are parsed to extract identifying features which are matched against other known and analyzed samples. Lastly, those matches that are determined to express a relationship are visualized as an edge connected pair of nodes in an undirected graph.
This approach consists of three steps. First, the received samples are processed by a sandbox environment to perform a dynamic behavior analysis. Second, the reports of the dynamic behavior analysis are parsed to extract identifying features which are matched against other known and analyzed samples. Lastly, those matches that are determined to express a relationship are visualized as an edge connected pair of nodes in an undirected graph.
ContributorsHolmes, James Edward (Author) / Ahn, Gail-Joon (Thesis advisor) / Dasgupta, Partha (Committee member) / Doupe, Adam (Committee member) / Arizona State University (Publisher)
Created2014
Description
Since its first report in 1976, many outbreaks of Legionella have been reported in the world. These outbreaks are a public health concern because of legionellosis, which cause Pontiac fever and Legionnaires disease. Legionnaires disease is a type of pneumonia responsible for the majority of the illness in the reported outbreaks. This study consists of an extensive literature review and experimental work on the aerosolization of Legionella and a bacterial surrogate under laboratory conditions. The literature review summarizes Legionella characteristics, legionellosis, potential sources of Legionella, disease outbreaks, collection and detection methodologies, environmental conditions for growth and survival of Legionella, Gaussian plume dispersion modeling, and recommendations for reducing potential Legionella outbreaks. The aerosolization and airborne dispersion of Legionella and E. coli was conducted separately inside of a closed environment. First, the bacterial cells were sprayed inside of an airtight box and then samples were collected using a microbial air sampler to measure the number of bacterial cells aerosolized and transported in air. Furthermore, a Gaussian plume dispersion model was used to estimate the dispersion under the experimental conditions and parameters. The concentration of Legionella was estimated for a person inhaling the air at three different distances away from the spray. The concentration of Legionella at distances of 0.1 km, 1 km, and 10 km away from the source was predicted to be 1.7x10-1, 2.2x10-3, and 2.6x10-5 CFU/m3, respectively.
ContributorsTaghdiri, Sepideh (Author) / Abbaszadegan, Morteza (Thesis advisor) / Fox, Peter (Committee member) / Estes, Robert (Committee member) / Arizona State University (Publisher)
Created2014
Description
Granular activated carbon (GAC) filters are final polishing step in the drinking water treatment systems for removal of dissolved organic carbon fractions. Generally filters are colonized by bacterial communities and their activity reduces biodegradable solutes allowing partial regeneration of GAC's adsorptive capacity. When the bacteria pass into the filtrate due to increased growth, microbiological quality of drinking water is compromised and regrowth in the distribution system occurs. Bacteria attached to carbon particles as biofilms or in conjugation with other bacteria were observed to be highly resistant to post filtration microbial mitigation techniques. Some of these bacteria were identified as pathogenic.
This study focuses on one such pathogen Legionella pneumophila which is resistant to environmental stressors and treatment conditions. It is also responsible for Legionnaires' disease outbreak through drinking water thus attracting attention of regulatory agencies. The work assessed the attachment and colonization of Legionella and heterotrophic bacteria in lab scale GAC media column filters. Quantification of Legionella and HPC in the influent, effluent, column's biofilms and on the GAC particles was performed over time using fluorescent microscopy and culture based techniques.
The results indicated gradual increase in the colonization of the GAC particles with HPC bacteria. Initially high number of Legionella cells were detected in the column effluent and were not detected on GAC suggesting low attachment of the cells to the particles potentially due to lack of any previous biofilms. With the initial colonization of the filter media by other bacteria the number of Legionella cells on the GAC particles and biofilms also increased. Presence of Legionella was confirmed in all the samples collected from the columns spiked with Legionella. Significant increase in the Legionella was observed in column's inner surface biofilm (0.25 logs up to 0.52 logs) and on GAC particles (0.42 logs up to 0.63 logs) after 2 months. Legionella and HPC attached to column's biofilm were higher than that on GAC particles indicating the strong association with biofilms. The bacterial concentration slowly increased in the effluent. This may be due to column's wall effect decreasing filter efficiency, possible exhaustion of GAC capacity over time and potential bacterial growth.
This study focuses on one such pathogen Legionella pneumophila which is resistant to environmental stressors and treatment conditions. It is also responsible for Legionnaires' disease outbreak through drinking water thus attracting attention of regulatory agencies. The work assessed the attachment and colonization of Legionella and heterotrophic bacteria in lab scale GAC media column filters. Quantification of Legionella and HPC in the influent, effluent, column's biofilms and on the GAC particles was performed over time using fluorescent microscopy and culture based techniques.
The results indicated gradual increase in the colonization of the GAC particles with HPC bacteria. Initially high number of Legionella cells were detected in the column effluent and were not detected on GAC suggesting low attachment of the cells to the particles potentially due to lack of any previous biofilms. With the initial colonization of the filter media by other bacteria the number of Legionella cells on the GAC particles and biofilms also increased. Presence of Legionella was confirmed in all the samples collected from the columns spiked with Legionella. Significant increase in the Legionella was observed in column's inner surface biofilm (0.25 logs up to 0.52 logs) and on GAC particles (0.42 logs up to 0.63 logs) after 2 months. Legionella and HPC attached to column's biofilm were higher than that on GAC particles indicating the strong association with biofilms. The bacterial concentration slowly increased in the effluent. This may be due to column's wall effect decreasing filter efficiency, possible exhaustion of GAC capacity over time and potential bacterial growth.
ContributorsSharma, Harsha (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2014
Description
Research in microbial biofuels has dramatically increased over the last decade. The bulk of this research has focused on increasing the production yields of cyanobacteria and algal cells and improving extraction processes. However, there has been little to no research on the potential impact of viruses on the yields of these phototrophic microbes for biofuel production. Viruses have the potential to significantly reduce microbial populations and limit their growth rates. It is therefore important to understand how viruses affect phototrophic microbes and the prevalence of these viruses in the environment. For this study, phototrophic microbes were grown in glass bioreactors, under continuous light and aeration. Detection and quantification of viruses of both environmental and laboratory microbial strains were measured through the use of a plaque assay. Plates were incubated at 25º C under continuous direct florescent light. Several environmental samples were taken from Tempe Town Lake (Tempe, AZ) and all the samples tested positive for viruses. Virus free phototrophic microbes were obtained from plaque assay plates by using a sterile loop to scoop up a virus free portion of the microbial lawn and transferred into a new bioreactor. Isolated cells were confirmed virus free through subsequent plaque assays. Viruses were detected from the bench scale bioreactors of Cyanobacteria Synechocystis PCC 6803 and the environmental samples. Viruses were consistently present through subsequent passage in fresh cultures; demonstrating viral contamination can be a chronic problem. In addition TEM was performed to examine presence or viral attachment to cyanobacterial cells and to characterize viral particles morphology. Electron micrographs obtained confirmed viral attachment and that the viruses detected were all of a similar size and shape. Particle sizes were measured to be approximately 50-60 nm. Cell reduction was observed as a decrease in optical density, with a transition from a dark green to a yellow green color for the cultures. Phototrophic microbial viruses were demonstrated to persist in the natural environment and to cause a reduction in algal populations in the bioreactors. Therefore it is likely that viruses could have a significant impact on microbial biofuel production by limiting the yields of production ponds.
ContributorsKraft, Kyle (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2014
Description
This study was devised to elucidate key information concerning the potential risk posed by Legionella in reclaimed water. A series of biological experiments and a recharge basin soil column study were conducted to examine the survival, growth, and transport of L. pneumophila through engineered reclaimed water systems. A pilot-scale, column study was set up to measure Legionella transport in the columns under Arizona recharge basin conditions. Two columns, A and B, were packed to a depth of 122 cm with a loamy sand media collected from a recharge basin in Mesa, Arizona. The grain size distribution of Column A differed from that of Column B by the removal of fines passing the #200 sieve. The different soil profiles represented by column A and B allowed for further investigation of soil attributes which influence the microbial transport mechanism. Both clear PVC columns stand at a height of 1.83 m with an inner diameter of 6.35 cm. Sampling ports were drilled into the column at the soil depths 15, 30, 60, 92, 122 cm. Both columns were acclimated with tertiary treated waste water and set to a flow rate of approximately 1.5 m/d. The columns were used to assess the transport of a bacterial indicator, E. coli, in addition to assessing the study's primary pathogen of concern, Legionella. Approximately, 〖10〗^7 to 〖10〗^9 E. coli cells or 〖10〗^6 to 〖10〗^7Legionella cells were spiked into the columns' head waters for each experiment. Periodically, samples were collected from each column's sampling ports, until a minimum of three pore volume passed through the columns.
The pilot-scale, column study produced novel results which demonstrated the mechanism for Legionella to be transported through recharge basin soil. E. coli was transported, through 122 cm of the media in under 6 hours, whereas, Legionella was transported, through the same distance, in under 30 hours. Legionella has been shown to survive in low nutrient conditions for over a year. Given the novel results of this proof of concept study, a claim can be made for the transport of Legionella into groundwater aquifers through engineering recharge basin conditions, in Central Arizona.
The pilot-scale, column study produced novel results which demonstrated the mechanism for Legionella to be transported through recharge basin soil. E. coli was transported, through 122 cm of the media in under 6 hours, whereas, Legionella was transported, through the same distance, in under 30 hours. Legionella has been shown to survive in low nutrient conditions for over a year. Given the novel results of this proof of concept study, a claim can be made for the transport of Legionella into groundwater aquifers through engineering recharge basin conditions, in Central Arizona.
ContributorsMcBurnett, Lauren Rae (Author) / Abbaszadegan, Morteza (Thesis advisor) / Alum, Absar (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2014