This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students. 

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The Magnetoplasmadynamic (MPD) thruster is an electromagnetic thruster that produces a higher specific impulse than conventional chemical rockets and greater thrust densities than electrostatic thrusters, but the well-known operational limit---referred to as ``onset"---imposes a severe limitation efficiency and lifetime. This phenomenon is associated with large fluctuations in operating voltage, high

The Magnetoplasmadynamic (MPD) thruster is an electromagnetic thruster that produces a higher specific impulse than conventional chemical rockets and greater thrust densities than electrostatic thrusters, but the well-known operational limit---referred to as ``onset"---imposes a severe limitation efficiency and lifetime. This phenomenon is associated with large fluctuations in operating voltage, high rates of electrode erosion, and three-dimensional instabilities in the plasma flow-field which cannot be adequately represented by two-dimensional, axisymmetric models. Simulations of the Princeton Benchmark Thruster (PBT) were conducted using the three-dimensional version of the magnetohydrodynamic (MHD) code, MACH. Validation of the numerical model is partially achieved by comparison to equivalent simulations conducted using the well-established two-dimensional, axisymmetric version of MACH. Comparisons with available experimental data was subsequently performed to further validate the model and gain insights into the physical processes of MPD acceleration. Thrust, plasma voltage, and plasma flow-field predictions were calculated for the PBT operating with applied currents in the range $6.5kA < J < 23.25kA$ and mass-flow rates of $1g/s$, $3g/s$, and $6g/s$. Comparisons of performance characteristics between the two versions of the code show excellent agreement, indicating that MACH3 can be expected to be as predictive as MACH2 has demonstrated over multiple applications to MPD thrusters. Predicted thrust for operating conditions within the range which exhibited no symptoms of the onset phenomenon experimentally also showed agreement between MACH3 and experiment well within the experimental uncertainty. At operating conditions beyond such values , however, there is a discrepancy---up to $\sim20\%$---which implies that certain significant physical processes associated with onset are not currently being modeled. Such processes are also evident in the experimental total voltage data, as is evident by the characteristic ``voltage hash", but not present in predicted plasma voltage. Additionally, analysis of the predicted plasma flow-field shows no breakdown in azimuthal symmetry, which is expected to be associated with onset. This implies that perhaps certain physical processes are modeled by neither MACH2 nor MACH3; the latter indicating that such phenomenon may not be inherently three dimensional and related to the plasma---as suggested by other efforts---but rather a consequence of electrode material processes which have not been incorporated into the current models.
ContributorsParma, Brian (Author) / Mikellides, Pavlos G (Thesis advisor) / Squires, Kyle (Committee member) / Herrmann, Marcus (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Microchannel heat sinks can possess heat transfer characteristics unavailable in conventional heat exchangers; such sinks offer compact solutions to otherwise intractable thermal management problems, notably in small-scale electronics cooling. Flow boiling in microchannels allows a very high heat transfer rate, but is bounded by the critical heat flux (CHF). This

Microchannel heat sinks can possess heat transfer characteristics unavailable in conventional heat exchangers; such sinks offer compact solutions to otherwise intractable thermal management problems, notably in small-scale electronics cooling. Flow boiling in microchannels allows a very high heat transfer rate, but is bounded by the critical heat flux (CHF). This thesis presents a theoretical-numerical study of a method to improve the heat rejection capability of a microchannel heat sink via expansion of the channel cross-section along the flow direction. The thermodynamic quality of the refrigerant increases during flow boiling, decreasing the density of the bulk coolant as it flows. This may effect pressure fluctuations in the channels, leading to nonuniform heat transfer and local dryout in regions exceeding CHF. This undesirable phenomenon is counteracted by permitting the cross-section of the microchannel to increase along the direction of flow, allowing more volume for the vapor. Governing equations are derived from a control-volume analysis of a single heated rectangular microchannel; the cross-section is allowed to expand in width and height. The resulting differential equations are solved numerically for a variety of channel expansion profiles and numbers of channels. The refrigerant is R-134a and channel parameters are based on a physical test bed in a related experiment. Significant improvement in CHF is possible with moderate area expansion. Minimal additional manufacturing costs could yield major gains in the utility of microchannel heat sinks. An optimum expansion rate occurred in certain cases, and alterations in the channel width are, in general, more effective at improving CHF than alterations in the channel height. Modest expansion in height enables small width expansions to be very effective.
ContributorsMiner, Mark (Author) / Phelan, Patrick E (Thesis advisor) / Herrmann, Marcus (Committee member) / Chen, Kangping (Committee member) / Arizona State University (Publisher)
Created2011
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Description
A numerical study of incremental spin-up and spin-up from rest of a thermally- stratified fluid enclosed within a right circular cylinder with rigid bottom and side walls and stress-free upper surface is presented. Thermally stratified spin-up is a typical example of baroclinity, which is initiated by a sudden increase in

A numerical study of incremental spin-up and spin-up from rest of a thermally- stratified fluid enclosed within a right circular cylinder with rigid bottom and side walls and stress-free upper surface is presented. Thermally stratified spin-up is a typical example of baroclinity, which is initiated by a sudden increase in rotation rate and the tilting of isotherms gives rise to baroclinic source of vorticity. Research by (Smirnov et al. [2010a]) showed the differences in evolution of instabilities when Dirichlet and Neumann thermal boundary conditions were applied at top and bottom walls. Study of parametric variations carried out in this dissertation confirmed the instability patterns observed by them for given aspect ratio and Rossby number values greater than 0.5. Also results reveal that flow maintained axisymmetry and stability for short aspect ratio containers independent of amount of rotational increment imparted. Investigation on vorticity components provides framework for baroclinic vorticity feedback mechanism which plays important role in delayed rise of instabilities when Dirichlet thermal Boundary Conditions are applied.
ContributorsKher, Aditya Deepak (Author) / Chen, Kangping (Thesis advisor) / Huang, Huei-Ping (Committee member) / Herrmann, Marcus (Committee member) / Arizona State University (Publisher)
Created2011
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Description

Within the last decade, it has become increasingly apparent that the effects of climate change are getting harder and harder to ignore. This fact has led to increased interest in sustainability and an increased pressure from consumers to have these ideals implemented into a variety of global industries. The fashion

Within the last decade, it has become increasingly apparent that the effects of climate change are getting harder and harder to ignore. This fact has led to increased interest in sustainability and an increased pressure from consumers to have these ideals implemented into a variety of global industries. The fashion industry, in particular, has been facing this pressure toward the desire for sustainable products is the fashion industry. Over the last five years, sustainability has become a main focus within the fashion industry. Countless brands now include sustainability within their marketing tactics and a variety of fashion organizations release reports on the unsustainable practices that currently dominate fashion production. These misleading marketing tactics and enigmatic intensive reports lead to confusion on what sustainable fashion actually looks like for both consumers and suppliers alike.<br/> This report attempts to help tackle this problem by using sustainable fashion certifications as a tactic to prove sustainability within business procedures. To compare eight of the most common fashion certifications, this paper assumes a systems thinking approach to creating an assessment framework, which is then applied to said certifications. To back up the importance of the topic, this paper presents key points of the current issues related to this case, which then contribute to the integration of basic sustainability assessment criteria and case-specific factors into overarching core criteria. The application of this framework is utilized to determine which certifications cover certain aspects of the curated core criteria. This is then used to present consumers and manufacturers with a more accurate understanding of each of these certifications. This information is then followed up with a recommendation of certifications that align most within researched-based consumer and supplier desires.

ContributorsReid, Christopher Patrick (Author) / Sewell, Dennita (Thesis director) / Kosak, Jessica (Committee member) / Department of Management and Entrepreneurship (Contributor, Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The aim of this creative project was to explore the ideas of impermanence and transience through the lens of different, largely non-western cultural backgrounds, and to incorporate what I learned into my own work as a painter. As part of this, I focused on the materials, techniques, visual strategies, and

The aim of this creative project was to explore the ideas of impermanence and transience through the lens of different, largely non-western cultural backgrounds, and to incorporate what I learned into my own work as a painter. As part of this, I focused on the materials, techniques, visual strategies, and philosophies that guided the creation of these works. The project consisted of a discrete research phase, during which time I gathered information and materials related to my topic, and a creation phase, when I focused largely on the production of oil paintings and ink paintings whose technique and/or subject matter pertained to impermanence. Research for the most part was conducted by utilizing online and physical collections of work to analyze the formal elements of the work along with the cultural context in which it was created. Ultimately the creative project resulted in a product of three oil paintings and five ink paintings.

ContributorsLewis, Evan G (Author) / Button, Melissa (Thesis director) / Schoebel, Henry (Committee member) / School of Art (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The purpose of this study is to examine the social and communicative barriers LGBTQIA+ students face when seeking healthcare at campus health and counseling services at Arizona State University. Social barriers relate to experiences and internalizations of societal stigma experienced by sexual and gender minority individuals as well as the

The purpose of this study is to examine the social and communicative barriers LGBTQIA+ students face when seeking healthcare at campus health and counseling services at Arizona State University. Social barriers relate to experiences and internalizations of societal stigma experienced by sexual and gender minority individuals as well as the anticipation of such events. Communication between patient and provider was assessed as a potential barrier with respect to perceived provider LGBTQIA+ competency. This study applies the minority stress model, considering experiences of everyday stigma and minority stress as a predictor of healthcare utilization among sexual and gender minority students. The findings suggest a small but substantial correlation between minority stress and healthcare use with 23.7% of respondents delaying or not receiving one or more types of care due to fear of stigma or discrimination. Additionally, communication findings indicate a lack of standardization of LGBTQIA+ competent care with experiences varying greatly between respondents.

ContributorsZahn, Jennica (Author) / Davis, Olga (Thesis director) / LeMaster, Benny (Committee member) / Watts College of Public Service & Community Solut (Contributor) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Though about 75 percent of American waste is recyclable, only 30 percent of it is actually recycled and less than ten percent of plastics disposed of in the United States in 2015 were recycled. A statistic like this demonstrates the immense need to increase recycling rates in order to move

Though about 75 percent of American waste is recyclable, only 30 percent of it is actually recycled and less than ten percent of plastics disposed of in the United States in 2015 were recycled. A statistic like this demonstrates the immense need to increase recycling rates in order to move towards cultivating a circular economy and benefiting the environment. With Arizona State University’s (ASU) extensive population of on-campus students and faculty, our team was determined to create a solution that would increase recycling rates. After conducting initial market research, our team incentives or education. We conducted market research through student surveys to determine the level of knowledge of our target audience and barriers to entry for local recycling and composting resources. Further, we gained insight into the medium of recycling and sustainability programs they would be interested in participating in. Overall, the results of our surveys demonstrated that a majority of students were interested in participating in these programs, if they were not already involved, and most students on-campus already had access to these resources. Despite having access to these sustainable practices, we identified a knowledge gap between students and their information on how to properly execute sustainable practices such as composting and recycling. In order to address this audience, our team created Circulearning, an educational program that aims to bridge the gap of knowledge and address immediate concerns regarding circular economy topics. By engaging audiences through our quick, accessible educational modules and teaching them about circular practices, we aim to inspire everyone to implement these practices into their own lives. Though our team began the initiative with a focus on implementing these practices solely to ASU campus, we decided to expand our target audience to implement educational programs at all levels after discovering the interest and need for this resource in our community. Our team is extremely excited that our Circulearning educational modules have been shared with a broad audience including students at Mesa Skyline High School, ASU students, and additional connections outside of ASU. With Circulearning, we will educate and inspire people of all ages to live more sustainably and better the environment in which we live.

ContributorsChakravarti, Renuka (Co-author) / Tam, Monet (Co-author) / Carr-Taylor, Kathleen (Co-author) / Byrne, Jared (Thesis director) / Marseille, Alicia (Committee member) / Jordan, Amanda (Committee member) / School of Art (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

The market for searching for food online is exploding. According to one expert at Google, “there are over 1 billion restaurant searches on Google every month” (Kelso, 2020). To capture this market and ride the general digital trend of internet personalization (as evidenced by Google search results, ads, YouTube and

The market for searching for food online is exploding. According to one expert at Google, “there are over 1 billion restaurant searches on Google every month” (Kelso, 2020). To capture this market and ride the general digital trend of internet personalization (as evidenced by Google search results, ads, YouTube and social media algorithms, etc), we created Munch to be an algorithm meant to help people find food they’ll love. <br/>Munch offers the ability to search for food by the restaurant or even as specific as a menu item (ex: search for the best Pad Thai). The best part? It is customized to your preferences based on a quiz you take when you open the app and from that point continuously learns from your behavior. This thesis documents the journey of the team who founded Munch, what progress we made and the reasoning behind our decisions, where this idea fits in a competitive marketplace, how much it could be worth, branding, and our recommendations for a successful app in the future.

ContributorsRajan, Megha (Co-author) / Krug, Hayden (Co-author) / Inocencio, Phillippe (Co-author) / Byrne, Jared (Thesis director) / Sebold, Brent (Committee member) / School of Art (Contributor) / Department of Supply Chain Management (Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

A collection of storyboards for a graphic novel adaptation of Edgar Allan Poe's "The Oval Portrait." These are drawn in a horror comic style and explore the gothic themes present in "The Oval Portrait" in a visual manner.

ContributorsRea, Sara Mateo (Author) / Fette, Donald (Thesis director) / Davis, Turner (Committee member) / School of Art (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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My project is designed to provide art education to incarcerated youth in Arizona. This project will address two current issues in Arizona; the underfunding of art programs and high rates of incarceration. As of 2021, there are no state-funded art programs in Arizona. Arizona is tied with Texas for the

My project is designed to provide art education to incarcerated youth in Arizona. This project will address two current issues in Arizona; the underfunding of art programs and high rates of incarceration. As of 2021, there are no state-funded art programs in Arizona. Arizona is tied with Texas for the eighth highest rate of incarceration in the country. In Arizona, 750 out of every 100,000 people are incarcerated. This project is an art course for incarcerated youth. The project includes a packet detailing the course content and assignment details, a class syllabus, a course flyer, and a certificate of completion. The course is intended to be taught at the Adobe Mountain School facility. The course is designed so that it can be implemented in other facilities in the future. The class will be taught by volunteers with a background in studio art, design, or art education. Each student will receive a course packet that they can use to keep track of information and assignments. Instructors will use the course packet to teach the class. The course focuses on drawing with charcoal and oil pastel, which will build a foundation in drawing skills. The course covers a twelve-week semester. The course content packet includes a week-by-week breakdown of the teaching material and project descriptions. The course consists of two main projects and preparatory work. The preparatory work includes vocabulary terms, art concepts, drawing guides, brainstorming activities, and drawing activities. The two main prompts are designed for students to explore the materials and to encourage self-reflection. The class is curated so that students can create art in a low-risk, non-judgemental environment. The course will also focus on establishing problem-solving and critical thinking skills through engaging activities.

ContributorsSheppard, Eve (Author) / Cornelia, Wells (Thesis director) / Jennifer, Nelson (Committee member) / School of Art (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05