Matching Items (528)
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Description
Proton exchange membrane fuel cells (PEMFCs) run on pure hydrogen and oxygen (or air), producing electricity, water, and some heat. This makes PEMFC an attractive option for clean power generation. PEMFCs also operate at low temperature which makes them quick to start up and easy to handle. PEMFCs have several

Proton exchange membrane fuel cells (PEMFCs) run on pure hydrogen and oxygen (or air), producing electricity, water, and some heat. This makes PEMFC an attractive option for clean power generation. PEMFCs also operate at low temperature which makes them quick to start up and easy to handle. PEMFCs have several important limitations which must be overcome before commercial viability can be achieved. Active areas of research into making them commercially viable include reducing the cost, size and weight of fuel cells while also increasing their durability and performance. A growing and important part of this research involves the computer modeling of fuel cells. High quality computer modeling and simulation of fuel cells can help speed up the discovery of optimized fuel cell components. Computer modeling can also help improve fundamental understanding of the mechanisms and reactions that take place within the fuel cell. The work presented in this thesis describes a procedure for utilizing computer modeling to create high quality fuel cell simulations using Ansys Fluent 12.1. Methods for creating computer aided design (CAD) models of fuel cells are discussed. Detailed simulation parameters are described and emphasis is placed on establishing convergence criteria which are essential for producing consistent results. A mesh sensitivity study of the catalyst and membrane layers is presented showing the importance of adhering to strictly defined convergence criteria. A study of iteration sensitivity of the simulation at low and high current densities is performed which demonstrates the variance in the rate of convergence and the absolute difference between solution values derived at low numbers of iterations and high numbers of iterations.
ContributorsArvay, Adam (Author) / Madakannan, Arunachalanadar (Thesis advisor) / Peng, Xihong (Committee member) / Liang, Yong (Committee member) / Subach, James (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Dye sensitized solar cells (DSSCs) are the third generation solar cells expected to outperform the first two generations of solar cells with their advantages of comparative higher efficiency and lower manufacturing costs. The manufacturing cost of Dye sensitized solar cells is one fifth of the conventional silicon solar cell. However,

Dye sensitized solar cells (DSSCs) are the third generation solar cells expected to outperform the first two generations of solar cells with their advantages of comparative higher efficiency and lower manufacturing costs. The manufacturing cost of Dye sensitized solar cells is one fifth of the conventional silicon solar cell. However, DSSCs have problems of low conversion efficiency, stability and reliability. Some effective approaches are required to improve their performance. This paper projects the work related to assessment and verification of the repeatability of the semi-automated fabrication process. Changes were introduced in to the fabrication process to enhance the efficiency and stability. The sealant step in the fabrication process was remodeled to a newer version with an improvement in efficiency from 11% to 11.8%. Sputtering was performed on counter electrode in 30 seconds intervals. Cells were fabricated to assess the performance & time dependent characteristics from EIS experiments. Series resistance increased three times in sputtered Pt electrode as compared to standard platinum electrode. This resulted in the degradation of conductive surface on glass electrode due to heavy bombardment of ions. The second phase of the project work relates to the incorporation of SWCNT on the TiO2 electrode and its effect on the cell efficiency. Different weight loadings (0.1 wt %, 0.2 wt%, 0.4 wt %) of SWCNTs were prepared and mixed with the commercial TiO2 paste and ethanol solvent. The TiO2-SWCNT layer was coated on the electrode using screen-printing technique. Both open circuit voltage and photocurrent were found to have measurable dependence on the TiO2 layer loading. Photo voltage ranged from ~0.73 V to ~0.43 V and photocurrent from ~8 to ~33 mA depending on weight percent loading. This behavior is due to aggregation of particles and most TiO2 aggregate particles are not connected to SWCNT. Transparency loss was observed leading to saturation in the photo current and limiting the light absorption within the TiO2 film.
ContributorsKinhal, Kartik (Author) / Munukutla, Lakshmi V (Thesis advisor) / Subach, James (Committee member) / Peng, Xihong (Committee member) / Arizona State University (Publisher)
Created2011
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Description

Analyzing Incident Rates of COVID-19 Before and After Stay-At-Home Orders Throughout the Southwestern U.S. with Respect to Limited Mobility Models

ContributorsTilleman, Karl Benson (Author) / Albuquerque, Fabio Suzart de (Thesis director) / Powers, Brian (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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In 2006, the Chilean government began the implementation of a “program of integrated childhood protection” called Chile Crece Contigo. This program involves the cooperation of the public health, education, and legal systems of Chile in the support of the Rights of the Child ratified by the United Nations in 1989,

In 2006, the Chilean government began the implementation of a “program of integrated childhood protection” called Chile Crece Contigo. This program involves the cooperation of the public health, education, and legal systems of Chile in the support of the Rights of the Child ratified by the United Nations in 1989, and guarantees accessibility to the diverse historical and cultural communities of Chile. This study seeks to evaluate the cultural pertinence of Chile Crece Contigo as implemented in the public health system of the predominantly Aymaran community of Putre and recommend policy changes and further investigation for the improvement of its implementation in all Aymaran communities of Northern Chile. These objectives were pursued through three weeks of observation of program activities as well as interviews with key implementers of Chile Crece Contigo in Putre’s Rural Family Health Center, a practitioner of traditional Aymaran medicine and mothers whose children are enrolled or were enrolled in a variety of the services offered by the program. These results highlighted successful efforts by health practitioners in Putre to provide culturally relevant care through Chile Crece Contigo, but also policy failures and ongoing uncertainty considering best practices for cultural pertinence within the program. The conclusion was reached that several funding and logistical policies of Chile Crece Contigo need to be altered to better serve this rural, Aymaran community. Also, several in-depth longitudinal studies on traditional Aymaran upbringing and the common socioeconomic conditions of the Aymaran community in Chile should be carried out in order to determine further policy changes and best practices for Chile Crece Contigo.

ContributorsPickett, Annaliese (Author) / Tompkins, Cynthia (Thesis director) / Hurtado, Ana Magdalena (Committee member) / School of Human Evolution & Social Change (Contributor) / Economics Program in CLAS (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description

This thesis worked towards the development of a parameterized 3D model off a cover that could go over any specific prosthesis depending on the parameters that had been entered. It also focused on gathering user inputs, which was done with the aid of the Amputee Coalition, that could be used

This thesis worked towards the development of a parameterized 3D model off a cover that could go over any specific prosthesis depending on the parameters that had been entered. It also focused on gathering user inputs, which was done with the aid of the Amputee Coalition, that could be used to create an aesthetic design on this cover. The Amputee Coalition helped to recruit participants through its website and social media platforms. Finally, multiple methods of creating a design were developed to increase the amount of customization that a user could have for their cover.

ContributorsFusaro, Gerard Anthony (Co-author) / Riley, Nicholas (Co-author) / Sugar, Thomas (Thesis director) / Redkar, Sangram (Committee member) / College of Integrative Sciences and Arts (Contributor) / Engineering Programs (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Artificial Intelligence’s facial recognition programs are inherently racially biased. The programs are not necessarily created with the intent to disproportionately impact marginalized communities, but through their data mining process of learning, they can become biased as the data they use may train them to think in a biased manner. Biased

Artificial Intelligence’s facial recognition programs are inherently racially biased. The programs are not necessarily created with the intent to disproportionately impact marginalized communities, but through their data mining process of learning, they can become biased as the data they use may train them to think in a biased manner. Biased data is difficult to spot as the programming field is homogeneous and this issue reflects underlying societal biases. Facial recognition programs do not identify minorities at the same rate as their Caucasian counterparts leading to false positives in identifications and an increase of run-ins with the law. AI does not have the ability to role-reverse judge as a human does and therefore its use should be limited until a more equitable program is developed and thoroughly tested.

ContributorsGurtler, Charles William (Author) / Iheduru, Okechukwu (Thesis director) / Fette, Donald (Committee member) / Economics Program in CLAS (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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This survey takes information on a participant’s beliefs on privacy security, the general digital knowledge, demographics, and willingness-to-pay points on if they would delete information on their social media, to see how an information treatment affects those payment points. This information treatment is meant to make half of the participants

This survey takes information on a participant’s beliefs on privacy security, the general digital knowledge, demographics, and willingness-to-pay points on if they would delete information on their social media, to see how an information treatment affects those payment points. This information treatment is meant to make half of the participants think about the deeper ramifications of the information they reveal. The initial hypothesis is that this information will make people want to pay more to remove their information from the web, but the results find a surprising negative correlation with the treatment.

ContributorsDeitrick, Noah Sumner (Author) / Silverman, Daniel (Thesis director) / Kuminoff, Nicolai (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Economics Program in CLAS (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description

Consider Steven Cryos’ words, “When disaster strikes, the time to prepare has passed.” Witnessing domestic water insecurity in events such as Hurricane Katrina, the instability in Flint, Michigan, and most recently the winter storms affecting millions across Texas, we decided to take action. The period between a water supply’s disruption

Consider Steven Cryos’ words, “When disaster strikes, the time to prepare has passed.” Witnessing domestic water insecurity in events such as Hurricane Katrina, the instability in Flint, Michigan, and most recently the winter storms affecting millions across Texas, we decided to take action. The period between a water supply’s disruption and restoration is filled with anxiety, uncertainty, and distress -- particularly since there is no clear indication of when, exactly, restoration comes. It is for this reason that Water Works now exists. As a team of students from diverse backgrounds, what started as an honors project with the Founders Lab at Arizona State University became the seed that will continue to mature into an economically sustainable business model supporting the optimistic visions and tenants of humanitarianism. By having conversations with community members, conducting market research, competing for funding and fostering progress amid the COVID-19 pandemic, our team’s problem-solving traverses the disciplines. The purpose of this paper is to educate our readers about a unique solution to emerging issues of water insecurity that are nested across and within systems who could benefit from the introduction of a personal water reclamation system, showcase our team’s entrepreneurial journey, and propose future directions that will this once pedagogical exercise to continue fulfilling its mission: To heal, to hydrate, and to help bring safe water to everyone.

ContributorsFilipek, Marina (Co-author) / Sadiasa, Aira (Co-author) / Reitzel, Gage (Co-author) / Byrne, Jared (Thesis director) / Sebold, Brent (Committee member) / Department of Finance (Contributor) / School of International Letters and Cultures (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Economics Program in CLAS (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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This thesis explores the idea of the Natural Law by looking at the ideas of three thinkers: Aristotle, Thomas Aquinas and John Locke. It answers the question of what the Natural Law is, and further explains the derivative of this Natural Law, Natural Right. It further substantiates a relationship between

This thesis explores the idea of the Natural Law by looking at the ideas of three thinkers: Aristotle, Thomas Aquinas and John Locke. It answers the question of what the Natural Law is, and further explains the derivative of this Natural Law, Natural Right. It further substantiates a relationship between the two. Finally, the thesis observes the prevalence these terms have in the American context, both in the Declaration of Independence as well as contemporary manifestations.

ContributorsJandhyala, Nikhil Viswanath (Author) / Seagrave, Adam (Thesis director) / Perez, Luke (Committee member) / Economics Program in CLAS (Contributor) / School of Civic & Economic Thought and Leadership (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Mathematical and analytical approach at the floor and diffuser of a Formula 1 vehicle and how they produce downforce. Reaches a conclusion about how engineers and aerodynamicists creates the desired effects underneath the vehicle to produce substantial downforce.

ContributorsMarcantonio, Nicholas Joseph (Author) / Rajadas, John (Thesis director) / Hillery, Scott (Committee member) / College of Integrative Sciences and Arts (Contributor) / Engineering Programs (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05