Matching Items (39)
Filtering by
- All Subjects: Mechanical Engineering
- All Subjects: Education
- Creators: Mechanical and Aerospace Engineering Program
Description
The following is a report that will evaluate the microstructure of the nickel-based superalloy Hastelloy X and its relationship to mechanical properties in different load conditions. Hastelloy X is of interest to the company AORA because its strength and oxidation resistance at high temperatures is directly applicable to their needs in a hybrid concentrated solar module. The literature review shows that the microstructure will produce different carbides at various temperatures, which can be beneficial to the strength of the alloy. These precipitates are found along the grain boundaries and act as pins that limit dislocation flow, as well as grain boundary sliding, and improve the rupture strength of the material. Over time, harmful precipitates form which counteract the strengthening effect of the carbides and reduce rupture strength, leading to failure. A combination of indentation and microstructure mapping was used in an effort to link local mechanical behavior to microstructure variability. Electron backscatter diffraction (EBSD) and energy dispersive spectroscopy (EDS) were initially used as a means to characterize the microstructure prior to testing. Then, a series of room temperature Vickers hardness tests at 50 and 500 gram-force were used to evaluate the variation in the local response as a function of indentation size. The room temperature study concluded that both the hardness and standard deviation increased at lower loads, which is consistent with the grain size distribution seen in the microstructure scan. The material was then subjected to high temperature spherical indentation. Load-displacement curves were essential in evaluating the decrease in strength of the material with increasing temperature. Through linear regression of the unloading portion of the curve, the plastic deformation was determined and compared at different temperatures as a qualitative method to evaluate local strength.
ContributorsCelaya, Andrew Jose (Author) / Peralta, Pedro (Thesis director) / Solanki, Kiran (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
This project created a teaching curriculum resource guide for using the popular series, The Hunger Games, in 6th-8th grade classrooms to introduce cultural issues such as child soldiers and international development to students. Studies have shown that literature can cultivate empathy and encourage youth to act. This combined with the expanding phenomenon of participatory culture and fandom activism as outlined by Henry Jenkins demonstrate the potential for youth to learn and act when given the opportunity and resources to do so. The curriculum is composed of three units: The first is a three-week reading of the books with various activities for students to really understand the narrative and source text. The second and third units address the issues of child soldiers and international development using The Hunger Games as a framework and a keystone to build connections so that these complex issues are accessible to youth. This project is a first step in the development of a curriculum that spans the full trilogy and covers a variety of current event topics.
ContributorsSimpson, Rebecca (Author) / Sivak, Henry (Thesis director) / Blasingame, James (Committee member) / Nelson, Margaret (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2014-05
Description
The study of the mechanical behavior of nanocrystalline metals using microelectromechanical systems (MEMS) devices lies at the intersection of nanotechnology, mechanical engineering and material science. The extremely small grains that make up nanocrystalline metals lead to higher strength but lower ductility as compared to bulk metals. Effects of strain-rate dependence on the mechanical behavior of nanocrystalline metals are explored. Knowing the strain rate dependence of mechanical properties would enable optimization of material selection for different applications and lead to lighter structural components and enhanced sustainability.
ContributorsHall, Andrea Paulette (Author) / Rajagopalan, Jagannathan (Thesis director) / Liao, Yabin (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
DescriptionThe heat island effect has resulted in an observational increase in averave ambient as well as surface temperatures and current photovoltaic implementation do not migitate this effect. Thus, the feasibility and performance of alternative solutions are explored and determined using theoretical, computational data.
ContributorsCoyle, Aidan John (Author) / Trimble, Steven (Thesis director) / Underwood, Shane (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
Description
The purpose of this creative thesis project is to create the framework of an educational class package based off of a course offered at Arizona State University. The course chosen for this project is an honors course titled Deductive Logic: Leadership and Management Techniques and is taught by Dean Kashiwagi, PhD. The class package is designed to be published over an online platform so students and professors from various institutions can access the material. Currently the platform is in its final stages of development and is slated to go live on July of 2014. The future development of the package will be geared towards facilitating interdisciplinary collaboration between institutions based off of course concepts.
ContributorsGunnoe, Jake Alan (Author) / Kashiwagi, Dean (Thesis director) / Kashiwagi, Jacob (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Del E. Webb Construction (Contributor)
Created2014-05
Description
The focus of education in the classroom traditionally is one of fact memorization and recall. The teaching process of linear knowledge progression is not always in tune with the way that the human brain actually processes, conceptualizes, and comprehends concepts and information. In an introductory engineering class, focused on materials engineering and its related concepts, a system of lecture interventions has been put in place to increase concept comprehension by supplementing lecture units with various activities, from additional worksheets, explicit concept discussions, and most recently, YouTube videos showcasing specific concepts and situations. In an attempt to correct the lack of actual concept comprehension, these interventions seek to interact with the human mind in a way that capitalizes on its ability to process and interpret non-linear knowledge and information.
Using a concept test given prior to the lecture unit, and after, the difference in scores is used to recognize if the concepts presented have actually been comprehended. Used specifically in a lecture unit on solubility and solutions, the concept test tested student’s knowledge of supersaturated, saturated, and unsaturated solutions. With a visual identification and a written explanation, the student’s ability to identify and explain the three solutions was tested.
In order to determine the cause of the change in score from pre- to post-test, an analysis of the change in scores and the effects of question type and solution type was conducted. The significant results are as follows:
The change in score from pre- to post-test was found to be significant, with the only difference between the two tests being the lecture unit and intervention
From pre- to post-test, solution type had a significant effect on the score, with the unsaturated solution being the most easily recognized and explained solution type
Students that felt that the YouTube videos greatly increased their concept comprehension, on average, performed better than their counterparts and also saw a greater increase their score from pre- to post-test
Using a concept test given prior to the lecture unit, and after, the difference in scores is used to recognize if the concepts presented have actually been comprehended. Used specifically in a lecture unit on solubility and solutions, the concept test tested student’s knowledge of supersaturated, saturated, and unsaturated solutions. With a visual identification and a written explanation, the student’s ability to identify and explain the three solutions was tested.
In order to determine the cause of the change in score from pre- to post-test, an analysis of the change in scores and the effects of question type and solution type was conducted. The significant results are as follows:
The change in score from pre- to post-test was found to be significant, with the only difference between the two tests being the lecture unit and intervention
From pre- to post-test, solution type had a significant effect on the score, with the unsaturated solution being the most easily recognized and explained solution type
Students that felt that the YouTube videos greatly increased their concept comprehension, on average, performed better than their counterparts and also saw a greater increase their score from pre- to post-test
ContributorsLinich, Christopher Graham (Author) / Krause, Stephen (Thesis director) / Middleton, James (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-05
Description
Through interviews with student participants in Barrett Summer Scholars during 2012, I uncovered how education in Arizona is failing and succeeding in meeting the needs of its high-achieving, oftentimes academically disillusioned students. Many high-achieving students feel underserved by their education and do not receive adequate challenges or one-on-one attention. Socioeconomic, ethnic, and racial limitations further contribute to the disenchantment of students and educational inequalities in the US and Arizona in particular. The Barrett Summer Scholars program itself intends to help engage these students, but it may be failing in its stated goals. Limited resources make it difficult for schools to pay as much attention to the high-achieving students as to the low-achieving, but Barrett might be able to help bridge this gap and provide students with one-on-one attention by way of student mentorship.
ContributorsManrique, Liliana (Author) / Popova, Laura (Thesis director) / Eder, James (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2014-05
Description
Bangladesh is facing one of the largest mass poisonings in human history with over 77 million people affected by contaminated water each and every day. Over the last few years, the 33 Buckets team has come together to help fulfill this clean water need through filtration, education, and an innovative distribution system to inspire and empower people in Bangladesh and across the world. To start this process, we are working with the Rahima Hoque Girls' school in the rural area of Raipura, Bangladesh to give girls access to clean water where they spend the most time. Through our assessment trip in May 2012, we were able to acquire technical data, community input, and partnerships necessary to move our project forward. Additionally, we realized that in many cases, including the Rahima Hoque school, water problems are not caused by a lack of technology, but rather a lack of utilization and maintenance long-term. To remedy this, 33 Buckets has identified a local filter to have installed at the school, and has designed a small-scale business focused on selling clean water in bulk to the surrounding community. Our price point and association with the Rahima Hoque Girls' school makes our solution sustainable. Plus, with the success of our first site, we see the potential to scale. We already have five nearby schools interested in working to implement similar water projects, and with over 100,000 schools in Bangladesh, many of which lack access to the right water systems, we have a huge opportunity to impact millions of lives. This thesis project describes our journey through this process. First, an introduction to our work prior to the assessment trip and through the ASU EPICS program is given. Second, we include quantitative and qualitative details regarding our May 2012 assessment trip to the Rahima Hoque school and Dhaka. Third, we recount some of the experiences we were able to participate in following the trip to Bangladesh, including the Dell Social Innovation Challenge. Fourth, we examine the technical filtration methods, business model development, and educational materials that will be used to implement our solution this summer. Finally, we include an Appendix with a variety of social venture competitions and applications that we have submitted over the past two years, in addition to other supplementary materials. These are excellent examples of our diligence and provide unique insight into the growth of our project.
ContributorsStrong, Paul Andrew (Co-author) / Shah, Pankti (Co-author) / Huerta, Mark (Co-author) / Henderson, Mark (Thesis director) / El Asmar, Mounir (Committee member) / LaBelle, Jeffrey (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
The data and results presented in this paper are part of a continuing effort to innovate and pioneer the future of engineering. The purpose of the following is to demonstrate the mechanical buckling characteristics in stiff thin film and soft substrate systems, and the importance of controlling them. In today's engineering research, wrinkling in systems in beginning to be viewed as a means for engineering innovation rather than failure. This research is important to further progress the possible applications the technology proposes, such as flexible electronics and tunable adhesives. This work utilizes a cost efficient and relatively easy method for generating and analyzing buckled systems. Ultra violate oxidation at ambient temperatures is exploited to create a stiff thin surface on rubber like polydimethylsiloxane, and couple with strain induction wrinkles are generated. Wrinkle characteristics such as amplitude, wavelengths and wetting properties were investigated. In simple cases, trends were confirmed that increased oxidation relates to increased buckle wavelengths, and increase in strain corresponds to a decrease in wavelength. Hierarchical buckles were produced in one-dimensional systems treated with a multi-step method; these were the first to be generated in the ASU labs. Unique topographic changes were produced in two-dimensional systems treated with the same method. Honeycomb or dome like structures were noted to occur, important as they undergo a different energy-reliving configuration compared to traditional parallel buckles. The information provided characterizes many aspects of the buckle phenomena and will allow for further inquiry into specific functions utilizing the technology to continue advancements in engineering.
ContributorsValacich, Michael James (Author) / Jiang, Hanqing (Thesis director) / Yu, Hongyu (Committee member) / Teng, Ma (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2013-05
Description
The goal of this research is to couple a physics-based model with adaptive algorithms to develop a more accurate and robust technique for structural health monitoring (SHM) in composite structures. The purpose of SHM is to localize and detect damage in structures, which has broad applications to improvements in aerospace technology. This technique employs PZT transducers to actuate and collect guided Lamb wave signals. Matching pursuit decomposition (MPD) is used to decompose the signal into a cross-term free time-frequency relation. This decoupling of time and frequency facilitates the calculation of a signal's time-of-flight along a path between an actuator and sensor. Using the time-of-flights, comparisons can be made between similar composite structures to find damaged regions by examining differences in the time of flight for each path between PZTs, with respect to direction. Relatively large differences in time-of-flight indicate the presence of new or more significant damage, which can be verified using a physics-based approach. Wave propagation modeling is used to implement a physics based approach to this method, which is coupled with adaptive algorithms that take into account currently existing damage to a composite structure. Previous SHM techniques for composite structures rely on the assumption that the composite is initially free of all damage on both a macro and micro-scale, which is never the case due to the inherent introduction of material defects in its fabrication. This method provides a novel technique for investigating the presence and nature of damage in composite structures. Further investigation into the technique can be done by testing structures with different sizes of damage and investigating the effects of different operating temperatures on this SHM system.
ContributorsBarnes, Zachary Stephen (Author) / Chattopadhyay, Aditi (Thesis director) / Neerukatti, Rajesh Kumar (Committee member) / Barrett, The Honors College (Contributor) / Department of English (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05