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- Genre: Doctoral Dissertation
Description
Engineering higher education is growing rapidly across the world, especially in the Global South. For many of these countries, the dominant engineering university models were imported and established by colonial European empires. These imported systems of higher education and engineering evolved to meet the local contexts of Europe and the United States in response to political and technological change. Today, engineers are being seen by national and international policymakers as key for innovation and technological development. Given that these models are exogenous to these countries and may carry embedded design values that correspond to the needs of the Global North, this study explores how engineering universities are aligned with societal values in Cameroon, a country with three colonial legacies, a highly diverse institutional landscape, and an engineering university system that is rapidly expanding.To assess the alignment of the Cameroonian engineering education system with Cameroonian perceptions of the common good, this dissertation employs a modified public value mapping method, comparing exogenous public values with endogenous perceptions of public value success or failure. Exogenous values embedded in global engineering education are determined using historical analysis of the evolution of engineering and higher education models in Europe and the United States. Endogenous perceptions of public value success or failure associated with Cameroonian engineering education are determined using a grounded analysis of 49 semi-structured interviews and focus groups. These two sets of values are mapped using historical narrative analysis to illuminate the social impacts of exogenous educational models.
This study finds that the engineering curriculum, institutional models of innovation, and methods of academic advancement are all perceived by Cameroonians to be misaligned with the public good. While a grassroots technology start-up culture, inspired by Silicon Valley, has been modified to meet the perceived common good. Furthermore, there is evidence that private grassroots engineering universities may hold stronger ties with their surrounding community than state supported institutions, thus addressing a societal value that would otherwise be neglected. This study suggests that both endogenous and modified exogenous models are more likely to meet perceptions of the common good, while models which are developed outside of a culture are more likely to be perceived as misaligned with societal goals.
ContributorsStribling, Eric (Author) / Parmentier, Mary Jane (Thesis advisor) / Dabars, William B. (Committee member) / Karwat, Darshan M. A. (Committee member) / Arizona State University (Publisher)
Created2022
Description
Adaptability has emerged as an essential skill in the engineering workforce due to constant technological and social change, engineering grand challenges, and the recent global pandemic. Although engineering employers and national reports have called for increased adaptability among engineers, what adaptability means in the engineering workplace has not been investigated. This dissertation uses qualitative semi-structured critical incident interviews with engineering managers from four corporations to better understand their perceptions of adaptability and then incorporates these findings into a scenario-based intervention for the engineering classroom. Thematic analysis of the interviews with engineering managers expanded existing frameworks for workplace adaptability to provide an engineering-specific understanding of adaptability as a construct. Managers’ perceptions of adaptability span six dimensions, each important when teaching this competency to engineering students: Creative Problem Solving; Interpersonal Adaptability; Handling Work Stress; Dealing with Uncertain and Unpredictable Situations; Learning New Technologies, Tasks, and Procedures; and Cultural Adaptability. Managers’ beliefs about the importance of a balanced approach to being adaptable in different work contexts, and the influence of personal characteristics such as self-awareness and having had specific experiences related to being adaptable, emerged from the findings as well. Composite narratives reflecting real-life situations encountered by engineers in the workplace were developed based on findings from the engineering manager interviews to provide greater texture to the data. Six of the narratives mapped to the six dimensions of adaptability identified in the thematic analysis, while the seventh narrative illustrated the importance of balance and context when deciding whether and how to be adaptable. They revealed how multiple dimensions of adaptability work together and that contextual factors like support from managers and coworkers are integral to an engineer’s adaptability. The narratives were condensed into two scenarios for use in a classroom-based intervention with first-year engineering students at a large public university. After the intervention, many students’ definitions of adaptability became more multi-dimensional and reflective of adaptability context and balance. Students also reported a better understanding of engineering work, an expanded definition of adaptability, greater delineation of adaptability, increased self-awareness, greater appreciation for the importance of adaptability balance, and enhanced feelings of job preparedness.
ContributorsSajadi, Susan (Author) / Brunhaver, Samantha R (Thesis advisor) / Kellam, Nadia N (Committee member) / Mckenna, Ann F (Committee member) / Arizona State University (Publisher)
Created2022
Description
Thermal susceptibility is one of the biggest challenges that asphalt pavements must overcome. Asphalt mixture’s thermal susceptibility can increase problems related to permanent deformation, and the expansion-contraction phenomenon triggers thermal cracking. Furthermore, there is a common worldwide interest in environmental impacts and pavements. Saving energy and mitigating the urban heat island (UHI) effect have been drawing the attention of researchers, governments, and industrial organizations. Pavements have been shown to play an important role in the UHI effect. Globally, about 90% of roadways are made of asphalt mixtures. The main objective of this research study involves the development and testing of an innovative aerogel-based product in the modification of asphalt mixtures to function as a material with unique thermal resistance properties, and potentially providing an urban cooling mechanism for the UHI. Other accomplishments included the development of test procedures to estimate the thermal conductivity of asphalt binders, the expansion-contraction of asphalt mixtures, and a computational tool to better understand the pavement’s thermal profile and stresses. Barriers related to the manufacturing and field implementation of the aerogel-based product were overcome. Unmodified and modified asphalt mixtures were manufactured at an asphalt plant to build pavement slabs. Thermocouples installed at top and bottom collected data daily. This data was valuable in understanding the temperature fluctuation of the pavement. Also, the mechanical properties of asphalt binders and mixtures with and without the novel product were evaluated in the laboratory. Fourier transform infrared (FTIR) and scanning electron microscope (SEM) analyses were also used to understand the interaction of the developed product with bituminous materials.
The modified pavements showed desirable results in reducing overall pavement temperatures and suppressing the temperature gradient, a key to minimize thermal cracking. The comprehensive laboratory tests showed favorable outcomes for pavement performance. The use of a pavement design software, and life cycle/cost assessment studies supported the use of this newly developed technology. Modified pavements would perform better than control in distresses related to permanent deformation and thermal cracking; they reduce tire/pavement noise, require less raw material usage during their life cycle, and have lower life cycle cost compared to conventional pavements.
ContributorsObando Gamboa, Carlos Javier (Author) / Kaloush, Kamil (Thesis advisor) / Mamlouk, Michael (Committee member) / Ozer, Hasan (Committee member) / Fini, Elham (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2022
Description
Achieving a viable process for advanced manufacturing of ceramics and metal-ceramic composites is a sought-after goal in a wide range of fields including electronics and sensors for harsh environments, microelectromechanical devices, energy storage materials, and structural materials, among others. In this dissertation, the processing, and manufacturing of ceramics and ceramic composites are addressed, specifically, a process for three-dimensional (3D) printing of polymer-derived ceramics (PDC), and a process for low-cost manufacturing as well as healing of metal-ceramic composites is demonstrated.Three-dimensional printing of ceramics is enabled by dispensing the preceramic polymer at the tip of a moving nozzle into a gel that can reversibly switch between fluid and solid states, and subsequently thermally cross-linking the entire printed part “at once” while still inside the same gel was demonstrated. The solid gel converts to fluid at the tip of the moving nozzle, allowing the polymer solution to be dispensed and quickly returns to a solid state to maintain the geometry of the printed polymer both during printing and the subsequent high-temperature (160 °C) cross-linking. After retrieving the cross-linked part from the gel, the green body is converted to ceramic by high-temperature pyrolysis. This scalable process opens new opportunities for low-cost and high-speed production of complex three-dimensional ceramic parts and will be widely used for high-temperature and corrosive environment applications, including electronics and sensors, microelectromechanical systems, energy, and structural applications.
Metal-ceramic composites are technologically significant as structural and functional materials and are among the most expensive materials to manufacture and repair. Hence, technologies for self-healing metal-ceramic composites are important. Here, a concept to fabricate and heal co-continuous metal-ceramic composites at room temperature were demonstrated. The composites were fabricated by infiltration of metal (here Copper) into a porous alumina preform (fabricated by freeze-casting) through electroplating; a low-temperature and low-cost process for the fabrication of such composites. Additionally, the same electroplating process was demonstrated for healing damages such as grooves and cracks in the original composite, such that the healed composite recovered its strength by more than 80%. Such technology may be expanded toward fully autonomous self-healing structures.
ContributorsMahmoudi, Mohammadreza (Author) / Minary-Jolandan, Majid (Thesis advisor) / Rajagopalan, Jagannathan (Committee member) / Cramer, Corson (Committee member) / Kang, Wonmo (Committee member) / Bhate, Dhruv (Committee member) / Arizona State University (Publisher)
Created2022
Description
Engineering leadership is an emerging research area in engineering education that aligns well with recent attention to the production of leaders and diverse engineers. While engineering leadership studies have highlighted elements such as the skills, traits, and behaviors required in pursuing and executing leadership, there is a narrow focus on the current work that also considers marginalized engineers' leadership experiences. Currently, studies that explore engineering leadership as investigations have occurred without consideration of the ways identity also factors into leadership experiences. This work considers the experiences and perspectives of early-career Black engineers engaged in leadership. The research questions that guided this study were: What are the experiences of early-career Black engineers that influence their leadership development? Through the stories of early career Black engineers, what conceptualizations of leadership are illuminated because of explicit and intentional consideration of racial identity in engineering leadership performance and development? How do early-career Black engineers navigate leadership in their professional journeys? The following frameworks guided this work: Komives' Leadership Identity Development Model, Esteban-Guitart's Funds of Identity, McGee's Stereotype Management Theory, and Campbell's Theory of the Monomyth. This qualitative study uses narrative inquiry and semi-structured interviews and captures the stories from six early-career Black engineers. The findings from these stories illuminated the following elements of engineering leadership: a sense of duty and agency to lead, the power of mentorship, and the complex role of managing identity in leadership. This work illustrates strategies encouraging engineering institutions, organizations, and enterprises to consider how leadership is conceptualized and actualized for Black engineers. This study intentionally centers on the authentic voices of Black engineers and considers how personal identity impacts the pursuit and execution of leadership and leadership development. Such considerations have the potential to influence engineering leadership development programs and initiatives that incorporate the unique perspectives of Black engineers.
ContributorsThomas, Katreena (Author) / Coley, Brooke (Thesis advisor) / Bekki, Jennifer (Committee member) / London, Jeremi (Committee member) / Arizona State University (Publisher)
Created2022
Description
To date, there is not a standardized method for consistently quantifying the performance of an automated driving system (ADS)-equipped vehicle (AV). The purpose of this dissertation is to contribute to a framework for such an approach referred to throughout as the operational safety assessment (OSA) methodology. Through this research, safety metrics are identified, researched, and analyzed to capture aspects of the operational safety of AVs, interacting with other salient objects. This dissertation outlines the approach for developing this methodology through a series of key steps including: (1) comprehensive literature review; (2) research and refinement of OSA metrics; (3) generation of MATLAB script for metric calculations; (4) generation of simulated events for analysis; (5) collection of real-world data for analysis; (6) review of OSA methodology results; and (7) discussion of future work to expand complexity, fidelity, and relevance aspects of the OSA methodology. The detailed literature review includes the identification of metrics historically used in both traditional and more recent evaluations of vehicle performance. Subsequently, the metric formulations are refined, and robust severity evaluations are proposed. A MATLAB script is then presented which was generated to calculate the metrics from any given source assuming proper formatting of the data. To further refine the formulations and the MATLAB script, a variety of simulated scenarios are discussed including car-following, intersection, and lane change situations. Additionally, a data collection activity is presented, leveraging the SMARTDRIVE testbed operated by Maricopa County Department of Transportation in Anthem, AZ to collect real-world data from an active intersection. Lastly, the efficacy of the OSA methodology with respect to the evaluation of vehicle performance for a set of scenarios is evaluated utilizing both simulated and real-world data. This assessment provides a demonstration of the ability and robustness of this methodology to evaluate vehicle performance for a given scenario. At the conclusion of this dissertation, additional factors including fidelity, complexity, and relevance are explored to contribute to a more comprehensive evaluation.
ContributorsComo, Steven Gerard (Author) / Wishart, Jeffrey (Thesis advisor) / Yang, Yezhou (Thesis advisor) / Chen, Yan (Committee member) / Favaro, Francesca (Committee member) / Arizona State University (Publisher)
Created2022
Description
District heating plays an important role in improving energy efficiency and providing thermal heat to buildings. Instead of using water as an energy carrier to transport sensible heat, this dissertation explores the use of liquid-phase thermochemical reactions for district heating as well as thermal storage. Chapters 2 and 3 present thermodynamic and design analyses for the proposed district heating system. Chapter 4 models the use of liquid-phase thermochemical reactions for on-site solar thermal storage. In brief, the proposed district heating system uses liquid-phase thermochemical reactions to transport thermal energy from a heat source to a heat sink. The separation ensures that the stored thermochemical heat can be stored indefinitely and/or transported long distances. The reactant molecules are then pumped over long distances to the heat sink, where they are combined in an exothermic reaction to provide heat. The product of the exothermic reaction is then pumped back to the heat source for re-use. The key evaluation parameter is the system efficiency.
The results demonstrate that with heat recovery, the system efficiency can be up to 77% when the sink temperature equals 25 C. The results also indicate that the appropriate chemical reaction candidates should have large reaction enthalpy and small reaction entropy. Further, the design analyses of two district heating systems, Direct District Heating (DDH) system and Indirect District Heating (IDH) system using the solvated case shows that the critical distance is 106m. When the distance is shorter than 1000,000m, the factors related to the chemical reaction at the user side and factors related to the separation process are important for the DDH system. When the distance is longer than 106m, the factors related to the fluid mechanic become more important. Because the substation of the IDH system degrades the quality of the energy, when the distance is shorter than 106m, the efficiency of the substation is significant. Lastly, I create models for on-site solar thermal storage systems using liquid-phase thermochemical reactions and hot water. The analysis shows that the thermochemical reaction is more competitive for long-duration storage applications. However, the heat recovery added to the thermochemical thermal storage system cannot help improving solar radiation absorption with high inlet temperature of the solar panel.
ContributorsZhang, Yanan (Author) / Wang, Robert (Thesis advisor) / Milcarek, Ryan (Committee member) / Parrish, Kristen (Committee member) / Phelan, Patrick (Committee member) / Rykaczewski, Konrad (Committee member) / Arizona State University (Publisher)
Created2022
Description
This dissertation focused on the development and application of state-of-the-art monitoring tools and analysis methods for tracking the fate of trace level contaminants in the natural and built water environments, using fipronil as a model; fipronil and its primary degradates (known collectively as fiproles) are among a group of trace level emerging environmental contaminants that are extremely potent arthropodic neurotoxins. The work further aimed to fill in data gaps regarding the presence and fate of fipronil in engineered water systems, specifically in a wastewater treatment plant (WWTP), and in an engineered wetland. A review of manual and automated “active” water sampling technologies motivated the development of two new automated samplers capable of in situ biphasic extraction of water samples across the bulk water/sediment interface of surface water systems. Combined with an optimized method for the quantification of fiproles, the newly developed In Situ Sampler for Biphasic water monitoring (IS2B) was deployed along with conventional automated water samplers, to study the fate and occurrence of fiproles in engineered water environments; continuous sampling over two days and subsequent analysis yielded average total fiprole concentrations in wetland surface water (9.9 ± 4.6 to 18.1 ± 4.6 ng/L) and wetland sediment pore water (9.1 ± 3.0 to 12.6 ± 2.1 ng/L). A mass balance of the WWTP located immediately upstream demonstrated unattenuated breakthrough of total fiproles through the WWTP with 25 ± 3 % of fipronil conversion to degradates, and only limited removal of total fiproles in the wetland (47 ± 13%). Extrapolation of local emissions (5–7 g/d) suggests nationwide annual fiprole loadings from WWTPs to U.S. surface waters on the order of about one half to three quarters of a metric tonne. The qualitative and quantitative data collected in this work have regulatory implications, and the sampling tools and analysis strategies described in this thesis have broad applicability in the assessment of risks posed by trace level environmental contaminants.
ContributorsSupowit, Samuel (Author) / Halden, Rolf U. (Thesis advisor) / Westerhoff, Paul (Committee member) / Johnson, Paul C (Committee member) / Arizona State University (Publisher)
Created2015
Description
Three dilemmas plague governance of scientific research and technological
innovation: the dilemma of orientation, the dilemma of legitimacy, and the dilemma of control. The dilemma of orientation risks innovation heedless of long-term implications. The dilemma of legitimacy grapples with delegation of authority in democracies, often at the expense of broader public interest. The dilemma of control poses that the undesirable implications of new technologies are hard to grasp, yet once grasped, all too difficult to remedy. That humanity has innovated itself into the sustainability crisis is a prime manifestation of these dilemmas.
Responsible innovation (RI), with foci on anticipation, inclusion, reflection, coordination, and adaptation, aims to mitigate dilemmas of orientation, legitimacy, and control. The aspiration of RI is to bend the processes of technology development toward more just, sustainable, and societally desirable outcomes. Despite the potential for fruitful interaction across RI’s constitutive domains—sustainability science and social studies of science and technology—most sustainability scientists under-theorize the sociopolitical dimensions of technological systems and most science and technology scholars hesitate to take a normative, solutions-oriented stance. Efforts to advance RI, although notable, entail one-off projects that do not lend themselves to comparative analysis for learning.
In this dissertation, I offer an intervention research framework to aid systematic study of intentional programs of change to advance responsible innovation. Two empirical studies demonstrate the framework in application. An evaluation of Science Outside the Lab presents a program to help early-career scientists and engineers understand the complexities of science policy. An evaluation of a Community Engagement Workshop presents a program to help engineers better look beyond technology, listen to and learn from people, and empower communities. Each program is efficacious in helping scientists and engineers more thoughtfully engage with mediators of science and technology governance dilemmas: Science Outside the Lab in revealing the dilemmas of orientation and legitimacy; Community Engagement Workshop in offering reflexive and inclusive approaches to control. As part of a larger intervention research portfolio, these and other projects hold promise for aiding governance of science and technology through responsible innovation.
ContributorsBernstein, Michael J. (Author) / Wiek, Arnim (Thesis advisor) / Wetmore, Jameson M. (Thesis advisor) / Grimm, Nancy (Committee member) / Anderies, John M (Committee member) / Arizona State University (Publisher)
Created2016
Description
A roofing manufacturer wants to differentiate themselves from other roofing manufacturers based on performance information. However, construction industry has revealed poor performance documentation in the last couple of decades. With no current developed performance measurement model in the industry, two roofing manufacturers approached the research group to implement a warranty program that measures the performance information of their systems and applicators. Moreover, the success of any project in the construction industry heavily relies upon the capability of the contractor(s) executing the project. Low-performing contractors are correlated with increased cost and delayed schedules, resulting in end-user dissatisfaction with the final product. Hence, the identification and differentiation of the high performing contractors from their competitors is also crucial. The purpose of this study is to identify and describe a new model for measuring manufacturer performance and differentiating contractor performance and capability for two roofing manufacturers (Manufacturer 1 and Manufacturer 2) in the roofing industry. The research uses multiple years of project data and customer satisfaction data collected for two roofing manufacturers for over 1,000 roofing contractors. The performance and end-user satisfaction was obtained for over 7,000 manufacturers' projects and each contractor associated with that project for cost, schedule, and quality metrics. The measurement process was successfully able to provide a performance measurement for the manufacturer based on the customer satisfaction and able to identify low performing contractors. This study presents the research method, the developed measurement model, and proposes a new performance measurement process that entities in the construction industry can use to measure performance.
ContributorsGajjar, Dhaval (Author) / Kashiwagi, Dean (Thesis advisor) / Sullivan, Kenneth (Thesis advisor) / Kashiwagi, Jacob (Committee member) / Arizona State University (Publisher)
Created2016