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Description
Phosphorus (P), an essential element for life, is becoming increasingly scarce, and its global management presents a serious challenge. As urban environments dominate the landscape, we need to elucidate how P cycles in urban ecosystems to better understand how cities contribute to — and provide opportunities to solve — problems

Phosphorus (P), an essential element for life, is becoming increasingly scarce, and its global management presents a serious challenge. As urban environments dominate the landscape, we need to elucidate how P cycles in urban ecosystems to better understand how cities contribute to — and provide opportunities to solve — problems of P management. The goal of my research was to increase our understanding of urban P cycling in the context of urban resource management through analysis of existing ecological and socio-economic data supplemented with expert interviews in order to facilitate a transition to sustainable P management. Study objectives were to: I) Quantify and map P stocks and flows in the Phoenix metropolitan area and analyze the drivers of spatial distribution and dynamics of P flows; II) examine changes in P-flow dynamics at the urban agricultural interface (UAI), and the drivers of those changes, between 1978 and 2008; III) compare the UAI's average annual P budget to the global agricultural P budget; and IV) explore opportunities for more sustainable P management in Phoenix. Results showed that Phoenix is a sink for P, and that agriculture played a primary role in the dynamics of P cycling. Internal P dynamics at the UAI shifted over the 30-year study period, with alfalfa replacing cotton as the main locus of agricultural P cycling. Results also suggest that the extent of P recycling in Phoenix is proportionally larger than comparable estimates available at the global scale due to the biophysical characteristics of the region and the proximity of various land uses. Uncertainty remains about the effectiveness of current recycling strategies and about best management strategies for the future because we do not have sufficient data to use as basis for evaluation and decision-making. By working in collaboration with practitioners, researchers can overcome some of these data limitations to develop a deeper understanding of the complexities of P dynamics and the range of options available to sustainably manage P. There is also a need to better connect P management with that of other resources, notably water and other nutrients, in order to sustainably manage cities.
ContributorsMetson, Genevieve (Author) / Childers, Daniel (Thesis advisor) / Aggarwal, Rimjhim (Thesis advisor) / Redman, Charles (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Restaurants have a cumulative impact on the environment, economy, and society. The majority of restaurants are small-to-medium enterprises (SMEs). Review of sustainability and industry literature revealed that considering restaurants as businesses with sustainable development options is the most appropriate way to evaluate their sustainable practices or lack thereof. Sustainable development

Restaurants have a cumulative impact on the environment, economy, and society. The majority of restaurants are small-to-medium enterprises (SMEs). Review of sustainability and industry literature revealed that considering restaurants as businesses with sustainable development options is the most appropriate way to evaluate their sustainable practices or lack thereof. Sustainable development is the means by which a company progresses towards achieving an identified set of sustainability goals and harnesses competitive advantage. The purpose of this thesis is to identify barriers to implementing sustainable practices in restaurants, and explore ways that restaurateurs can incorporate sustainable business practices. Energy consumption, water use, waste production, and food throughput are the four sustainability indicators addressed in this thesis. Interviews were conducted with five Tempe, Arizona restaurants, two of which consider their operations to be sustainable, and three of which are traditional restaurants. Results show that for traditional restaurants, the primary barriers to implementing sustainable business practices are cost, lack of awareness, and space. For sustainability-marketed restaurants, the barriers included a lack of knowledge or legal concerns. The sustainability-marketed restaurants have energy-efficient equipment and locally source a majority of their food purchases. There is a marked difference between the two types of restaurants in perception of barriers to sustainable business practices. I created a matrix to identify whether each indicator metric was applicable and present at a particular restaurant, and the potential barriers to implementing sustainable practices in each of the four indicator areas. Restaurants can use the assessment matrix to compare their current practices with sustainable practices and find ways to implement new or enhance existing sustainable practices. Identifying the barriers from within restaurants increases our understanding of the reasons why sustainable practices are not automatically adopted by SMEs. The assessment matrix can help restaurants overcome barriers to achieving sustainability by highlighting how to incorporate sustainable business practices.
ContributorsFreeman, Emily McConnell (Author) / Eakin, Hallie (Thesis advisor) / Basile, George (Thesis advisor) / Williams, Eric D. (Committee member) / Arizona State University (Publisher)
Created2011
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Description

Laminated composites are increasingly being used in various industries including <br/>automotive and aerospace. Under a variety of extreme loading conditions such as low and <br/>high-velocity impacts and crash, laminated composites delaminate. To understand how and<br/>when delamination occurs, two types of laboratory tests are conducted - End-notched <br/>Flexure (ENF) test and

Laminated composites are increasingly being used in various industries including <br/>automotive and aerospace. Under a variety of extreme loading conditions such as low and <br/>high-velocity impacts and crash, laminated composites delaminate. To understand how and<br/>when delamination occurs, two types of laboratory tests are conducted - End-notched <br/>Flexure (ENF) test and Double Cantilever Beam (DCB) test. The ENF test is designed to <br/>find the mode II interlaminar fracture toughness, and the DCB test, the mode I interlaminar <br/>fracture toughness. In this thesis, thermopressed Honeywell Spectra Shield® 5231 <br/>composite specimens made of ultra-high molecular weight polyethylene (UHMWPE), <br/>manufactured under two different pressures (3000 psi and 6000 psi), are tested in the <br/>laboratory to find its delamination properties. The test specimen preparation, experimental <br/>procedures, and data reduction to determine the mode I and mode II interlaminar fracture <br/>properties are discussed. The ENF test results show a 15.8% increase in strain energy <br/>release rate for the 6000 psi specimens when compared to the 3000 psi specimens. <br/>Conducting the DCB tests proved to be challenging due to the low compressive strength <br/>of the material and hence required modifications to the test specimens. An estimate of the <br/>mode I interlaminar fracture toughness was found for only two of the 6000 psi specimens.

ContributorsRyder, Chandler (Author) / Rajan, Subramaniam (Thesis director) / Khaled, Bilal (Committee member) / Neithalath, Narayanan (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities

Long distance travel around the globe can potentially be revolutionized with the use of an intercontinental rocket that uses low earth orbit as its medium. This transport system can increase growth in many new businesses like tourism travel between the continents. This research evaluates the technical and non-technical possibilities of using a double-stage reusable rocket, where the second stage is also a reusable, rocket-powered passenger vehicle using a low earth orbit space journey with a stabilized re-entry method that ensures passenger comfortability. A potential network of spaceports spanning the globe is postulated within a range of 4,000 km to 8,000 km(2,160 nm to 4,320 nm) of each other, and each located within an hour by any other means of ground transport to population hubs greater than four million. This will help further connect the world as the journey from one major city to another would take at most an hour, and no point on the habited continents would be more than 4,000 km(2,160 nm) from a spaceport. It is assumed that the costs of an international first class flight ticket are in the thousands of dollars range showing how there is a potential market for this type of travel network. The reasoning and analysis, through a literature review, for an intercontinental rocket vehicle is presented along with the various aspects of the possibility of this kind of travel network coming to fruition in the near future.

ContributorsRanganathan, Anirudh (Co-author) / Karthikeyan, Sayish (Co-author) / Takahashi, Timothy (Thesis director) / Niemczyk, Mary (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

A novel concept for integration of flame-assisted fuel cells (FFC) with a gas turbine is analyzed in this paper. Six different fuels (CH4, C3H8, JP-4, JP-5, JP-10(L), and H2) are investigated for the analytical model of the FFC integrated gas turbine hybrid system. As equivalence ratio increases, the efficiency of

A novel concept for integration of flame-assisted fuel cells (FFC) with a gas turbine is analyzed in this paper. Six different fuels (CH4, C3H8, JP-4, JP-5, JP-10(L), and H2) are investigated for the analytical model of the FFC integrated gas turbine hybrid system. As equivalence ratio increases, the efficiency of the hybrid system increases initially then decreases because the decreasing flow rate of air begins to outweigh the increasing hydrogen concentration. This occurs at an equivalence ratio of 2 for CH4. The thermodynamic cycle is analyzed using a temperature entropy diagram and a pressure volume diagram. These thermodynamic diagrams show as equivalence ratio increases, the power generated by the turbine in the hybrid setup decreases. Thermodynamic analysis was performed to verify that energy is conserved and the total chemical energy going into the system was equal to the heat rejected by the system plus the power generated by the system. Of the six fuels, the hybrid system performs best with H2 as the fuel. The electrical efficiency with H2 is predicted to be 27%, CH4 is 24%, C3H8 is 22%, JP-4 is 21%, JP-5 is 20%, and JP-10(L) is 20%. When H2 fuel is used, the overall integrated system is predicted to be 24.5% more efficient than the standard gas turbine system. The integrated system is predicted to be 23.0% more efficient with CH4, 21.9% more efficient with C3H8, 22.7% more efficient with JP-4, 21.3% more efficient with JP-5, and 20.8% more efficient with JP-10(L). The sensitivity of the model is investigated using various fuel utilizations. When CH4 fuel is used, the integrated system is predicted to be 22.7% more efficient with a fuel utilization efficiency of 90% compared to that of 30%.

ContributorsRupiper, Lauren Nicole (Author) / Milcarek, Ryan (Thesis director) / Wang, Liping (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / School for Engineering of Matter,Transport & Enrgy (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

While many 3D printed structures are rigid and stationary, the potential for complex geometries offers a chance for creative and useful motion. Printing structures larger than the print bed, reducing the need for support materials, maintaining multiple states without actuation, and mimicking origami folding are some of the opportunities offered

While many 3D printed structures are rigid and stationary, the potential for complex geometries offers a chance for creative and useful motion. Printing structures larger than the print bed, reducing the need for support materials, maintaining multiple states without actuation, and mimicking origami folding are some of the opportunities offered by 3D printed hinges. Current efforts frequently employ advanced materials and equipment that are not available to all users. The purpose of this project was to develop a parametric, print-in-place, self-locking hinge that could be printed using very basic materials and equipment. Six main designs were developed, printed, and tested for their strength in maintaining a locked position. Two general design types were used: 1) sliding hinges and 2) removable pin hinges. The test results were analyzed to identify and explain the causes of observed trends. The amount of interference between the pin vertex and knuckle hole edge was identified as the main factor in hinge strength. After initial testing, the designs were modified and applied to several structures, with successful results for a collapsible hexagon and a folding table. While the initial goal was to have one CAD model as a final product, the need to evaluate tradeoffs depending on the exact application made this impossible. Instead, a set of design guidelines was created to help users make strategic decisions and create their own design. Future work could explore additional scaling effects, printing factors, or other design types.

ContributorsAndreotti, Jaimee Jeannette (Author) / Bhate, Dhruv (Thesis director) / Aukes, Daniel (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Increasing reliable produce farming and clean energy generation in the southwestern United States will be important for increasing the food supply for a growing population and reducing reliance on fossil fuels to generate energy. Combining greenhouses with photovoltaic (PV) films can allow both food and electric power to be produced

Increasing reliable produce farming and clean energy generation in the southwestern United States will be important for increasing the food supply for a growing population and reducing reliance on fossil fuels to generate energy. Combining greenhouses with photovoltaic (PV) films can allow both food and electric power to be produced simultaneously. This study tests if the combination of semi-transparent PV films and a transmission control layer can generate energy and spectrally control the transmission of light into a greenhouse. Testing the layer combinations in a variety of real-world conditions, it was shown that light can be spectrally controlled in a greenhouse. The transmission was overall able to be controlled by an average of 11.8% across the spectrum of sunlight, with each semi-transparent PV film able to spectrally select transmission of light in both the visible and near-infrared light wavelength. The combination of layers was also able to generate energy at an average efficiency of 8.71% across all panels and testing conditions. The most efficient PV film was the blue dyed, at 9.12%. This study also suggests additional improvements for this project, including the removal of the red PV film due to inefficiencies in spectral selection and additional tests with new materials to optimize plant growth and energy generation in a variety of light conditions.

ContributorsGunderson, Evan (Author) / Phelan, Patrick (Thesis director) / Villalobos, Rene (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

This project is focused on exploring the features and benefits of self-cleaning seats. The Founder's Lab team conducted research to determine the proper markets for this technology.

ContributorsYang, Tiger (Author) / Byrne, Jared (Thesis director) / Nimmagadda, Viraj (Committee member) / Jawahar, Nandita (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

In 2020, the world was swept by a global pandemic. It disrupted the lives of millions; many lost their jobs, students were forced to leave schools, and children were left with little to do while quarantined at their houses. Although the media outlets covered very little of how children were

In 2020, the world was swept by a global pandemic. It disrupted the lives of millions; many lost their jobs, students were forced to leave schools, and children were left with little to do while quarantined at their houses. Although the media outlets covered very little of how children were being affected by COVID-19, it was obvious that their group was not immune to the issues the world was facing. Being stuck at home with little to do took a mental and physical toll on many kids. That is when EVOLVE Academy became an idea; our team wanted to create a fully online platform for children to help them practice and evolve their athletics skills, or simply spend part of their day performing a physical and health activity. Our team designed a solution that would benefit children, as well as parents that were struggling to find engaging activities for their kids while out of school. We quickly encountered issues that made it difficult for us to reach our target audience and make them believe and trust our platform. However, we persisted and tried to solve and answer the questions and problems that came along the way. Sadly, the same pandemic that opened the widow for EVOLVE Academy to exist, is now the reason people are walking away from it. Children want real interaction. They want to connect with other kids through more than just a screen. Although the priority of parents remains the safety and security of their kids, parents are also searching and opting for more “human” interactions, leaving EVOLVE Academy with little room to grow and succeed.

ContributorsWhitelocke, Kailas N (Co-author) / Hernandez, Melany (Co-author) / Parmenter, Taylor (Co-author) / Byrne, Jared (Thesis director) / Lee, Christopher (Committee member) / Kunowski, Jeff (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

The research presented in this Honors Thesis provides development in machine learning models which predict future states of a system with unknown dynamics, based on observations of the system. Two case studies are presented for (1) a non-conservative pendulum and (2) a differential game dictating a two-car uncontrolled intersection scenario.

The research presented in this Honors Thesis provides development in machine learning models which predict future states of a system with unknown dynamics, based on observations of the system. Two case studies are presented for (1) a non-conservative pendulum and (2) a differential game dictating a two-car uncontrolled intersection scenario. In the paper we investigate how learning architectures can be manipulated for problem specific geometry. The result of this research provides that these problem specific models are valuable for accurate learning and predicting the dynamics of physics systems.<br/><br/>In order to properly model the physics of a real pendulum, modifications were made to a prior architecture which was sufficient in modeling an ideal pendulum. The necessary modifications to the previous network [13] were problem specific and not transferrable to all other non-conservative physics scenarios. The modified architecture successfully models real pendulum dynamics. This case study provides a basis for future research in augmenting the symplectic gradient of a Hamiltonian energy function to provide a generalized, non-conservative physics model.<br/><br/>A problem specific architecture was also utilized to create an accurate model for the two-car intersection case. The Costate Network proved to be an improvement from the previously used Value Network [17]. Note that this comparison is applied lightly due to slight implementation differences. The development of the Costate Network provides a basis for using characteristics to decompose functions and create a simplified learning problem.<br/><br/>This paper is successful in creating new opportunities to develop physics models, in which the sample cases should be used as a guide for modeling other real and pseudo physics. Although the focused models in this paper are not generalizable, it is important to note that these cases provide direction for future research.

ContributorsMerry, Tanner (Author) / Ren, Yi (Thesis director) / Zhang, Wenlong (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05