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This paper explores the consequences of cleaning rescue ropes with common disinfectants and cleansers in order to assess their usability in cleaning ropes contaminated with blood borne pathogens. Using a modified version of an industry-standard testing procedure and in-depth statistical analysis, it characterizes the effect each chemical has on the mechanical properties of the rope. The experiment measured the strength and elastic properties of rope core fibers soaked in different chemicals and at different concentration levels. The data show that certain common solutions for cleaning equipment are, in fact, damaging to the equipment and thus dangerous to the users. Even products marketed for climbing ropes were found to be potentially hazardous. The results also demonstrate a curious phenomenon occurring within the washing process that causes a shift in the elastic properties of the fibers, prompting additional research. Further work is needed to expand the breadth and depth of these results and to make effective recommendations to the rope industry and rescue professionals regarding rope care and maintenance.
ContributorsDenike, Andrew Nicholas (Author) / Middleton, James (Thesis director) / Liao, Yabin (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of this paper is to discover what geometric characteristics of a wing and airfoil help to maximize leading edge suction through experimental testing. Three different stages of testing were conducted: a Proof of Concept, a Primary Experiment, and a Secondary Experiment. The Proof of Concept shows the effects of leading edge suction and the benefits it can posses. The Primary Experiment provided inconclusive data due to inaccuracies in the equipment. As a result, the Secondary Experiment was conducted in order to reduce the error effect as much as possible on the data. Unfortunately the Secondary Experiment provided inaccurate data as well. However, this paper does provide enough evidence to begin to question some of the long held beliefs regarding theoretical induced drag and whether it is true under all circumstances, or if it is only a good approximation for airfoils with full leading-edge suction effects.
ContributorsMorrow, Martin (Author) / Takahashi, Timothy (Thesis director) / Middleton, James (Committee member) / School for the Engineering of Matter, Transport, and Energy (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The purpose of this investigation is to computationally investigate instabilities appearing in the wake of a simulated helicopter rotor. Existing data suggests further understanding of these instabilities may yield design changes to the rotor blades to reduce the acoustic signature and improve the aerodynamic efficiencies of the aircraft. Test cases of a double-bladed and single-bladed rotor have been run to investigate the causes and types of wake instabilities, as well as compare them to the short wave, long wave, and mutual inductance modes proposed by Widnall[2]. Evaluation of results revealed several perturbations appearing in both single and double-bladed wakes, the origin of which was unknown and difficult to trace. This made the computations not directly comparable to theoretical results, and drawing into question the physical flight conditions being modeled. Nonetheless, they displayed a wake structure highly sensitive to both computational and physical disturbances; thus extreme care must be taken in constructing grids and applying boundary conditions when doing wake computations to ensure results relevant to the complex and dynamic flight conditions of physical aircraft are generated.
ContributorsDrake, Nicholas Spencer (Author) / Wells, Valana (Thesis director) / Squires, Kyle (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2014-12
Description
Mathematics is an increasingly critical subject and the achievement of students in mathematics has been the focus of many recent reports and studies. However, few studies exist that both observe and discuss the specific teaching and assessment techniques employed in the classrooms across multiple countries. The focus of this study is to look at classrooms and educators across six high achieving countries to identify and compare teaching strategies being used. In Finland, Hong Kong, Japan, New Zealand, Singapore, and Switzerland, twenty educators were interviewed and fourteen educators were observed teaching. Themes were first identified by comparing individual teacher responses within each country. These themes were then grouped together across countries and eight emerging patterns were identified. These strategies include students active involvement in the classroom, students given written feedback on assessments, students involvement in thoughtful discussion about mathematical concepts, students solving and explaining mathematics problems at the board, students exploring mathematical concepts either before or after being taught the material, students engagement in practical applications, students making connections between concepts, and students having confidence in their ability to understand mathematics. The strategies identified across these six high achieving countries can inform educators in their efforts of increasing student understanding of mathematical concepts and lead to an improvement in mathematics performance.
ContributorsAnglin, Julia Mae (Author) / Middleton, James (Thesis director) / Vicich, James (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor)
Created2014-12
Description
This thesis focused on the development of a system that can sense light intensity and then control a smart film to provide the optimal light intensity for cyanobacteria. The overarching goal of this project is to further the study of biofuels as an alternative energy source by increasing growth rates. If more algae or cyanobacteria can be grown per day, then the cost to produce the biofuel will decrease. To achieve this goal, PDLC (polymer dispersed liquid crystal) film was selected to be controlled due to its unique properties. It can be controlled with electricity and has variable states, in other words, not restricted to simply on or off. It also blocks 80% ultraviolet light and reduces thermal heat gain by 40% which is an important consideration for outdoor growing situations. To control the film, a simple control system was created using an Arduino Uno, SainSmart 8 channel relay board, an inverter, and a power supply. A relay board was utilized to manage the 40 volts required by the PDLC film and protected the electronics on the Arduino Uno. To sense the light intensity, the Arduino Uno was connected to a photoresistor, which changes resistance with light intensity. A 15 day test of two flasks of Cyanobacteria Synechocycstis sp. 6803, one shaded by the PDLC film, and the other unshaded, yielded 65% difference in optical densities. Overall, the experiment showed promise for controlling light intensity for photobioreactors. Ideally, this research will help to optimize light intensities when growing cyanobacteria or algae outdoors or it will help to discover what an ideal light intensity is by allowing a researcher unprecedented control.
ContributorsRoney, Kitt Alicia (Author) / Nielsen, David (Thesis director) / Middleton, James (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
The purpose of my Honors Thesis was to generate a tool that could be implemented by Aerospace students at Arizona State University. This tool was created using MatLab which is the current program students are using. The modeling system that was generated goes step-by-step through the flow of a two spool gas turbine engine. The code was then compared to an ideal case engine with predictable values. It was found to have less than a 3 percent error for these parameters, which included optimal net work produced, optimal overall pressure ratio, and maximum pressure ratio. The modeling system was then run through a parametric analysis. In the first case, the bypass ratio was set to 0 and the freestream Mach number was set to 0. The second case was with a bypass ratio of 0 and fresstream Mach number of 0.85. The third case was with a bypass ratio of 5 and freestream Mach number of 0. The fourth case was with a bypass ratio of 5 and fresstream Mach number of 0.85. Each of these cases was run at various overall pressure ratios and maximum Temperatures of 1500 K, 1600 K and 1700 K. The results modeled the behavior that was expected. As the freestream Mach number was increased, the thrust decreased and the thrust specific fuel consumption increased, corresponding to an increase in total pressure at the combustor inlet. It was also found that the thrust was increased and the thrust specific fuel consumption decreased as the bypass ratio was increased. These results also make sense as there is less airflow passing through the engine core. Finally the engine was compared to two real engines. Both of which are General Electric G6 series engines. For the 80C2A3 engine, the percent difference between thrust and thrust specific fuel consumption was less than five percent. For the 50B, the thrust was below a two percent difference, but the thrust specific fuel consumption clearly provided inaccurate results. This could be caused by the lack of inputs provided by General Electric. The amount of fuel injected is largely dependent on the maximum temperature which is not available to the public. Overall, the code produces comparable results to real engines and can display how isolating and modifying a certain parameter effects engine performance.
ContributorsCook, Rachel Nicole (Author) / Dahm, Werner (Thesis director) / Lee, Taewoo (Committee member) / Wells, Valana (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
The flipped classroom is a teaching method that flips the activities done in and out of class, i.e., concepts are learned out of class and problems are worked in class under the supervision of the instructor. Studies have indicated several benefits of the FC, including improved performance and engagement. In the past years, further studies have investigated the benefits of FC in statics, dynamics, and mechanics of materials courses and indicate similar performance benefits. However, these studies address a need for additional studies to validate their results due to the short length of their research or small classroom size. In addition, many of these studies do not measure student attitudes, such as self-efficacy, or the difference in time spent out of class on coursework. The objective of this research is to determine the effectiveness of the flipped classroom system (FC) in comparison to the traditional classroom system (TC) in a large mechanics of materials course. Specifically, it aims to measure student performance, student self-efficacy, student attitudes on lecture quality, motivation, attendance, hours spent out of class, practice, and support, and difference in impact between high, middle, and low achieving students. In order to accomplish this, three undergraduate mechanics of materials courses were analyzed during the spring 2015 semester. One FC section served as the experimental group (92 students), while the two TC sections served as the control group (125 students). To analyze student self-efficacy and attitudes, a survey instrument was designed to measure 18 variables and was administered at the end of the semester. Standardized core outcomes were compared between groups to analyze performance. This paper presents the specific course framework used in this FC, detailed results of the quantitative and qualitative analysis, and discussion of strengths and weaknesses. Overall, an overwhelming majority of students were satisfied with FC and would like more of their classes taught using FC. Strengths of this teaching method include greater confidence, better focus, higher satisfaction with practice in class and assistance received from instructors and peers, more freedom to express ideas and questions in class, and less time required outside of class for coursework. Results also suggest that this method has a greater positive impact on high and low achieving students and leads to higher performance. The criticisms made by students focused on lecture videos to have more worked examples. Overall, results suggest that FC is more effective than TC in a large mechanics of materials course.
ContributorsLee, Andrew Ryan (Author) / Zhu, Haolin (Thesis director) / Middleton, James (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of this paper is to provide a new and improved design method for the Formula Society of Automotive Engineering (FSAE) team. There are five tasks that I accomplish in this paper: 1. I describe how the FSAE team is currently designing their car. This allows the reader to understand where the flaws might arise in their design method. 2. I then describe the key aspects of systems engineering design. This is the backbone of the method I am proposing, and it is important to understand the key concepts so that they can be applied to the FSAE design method. 3. I discuss what is available in the literature about race car design and optimization. I describe what other FSAE teams are doing and how that differs from systems engineering design. 4. I describe what the FSAE team at Arizona State University (ASU) should do to improve their approach to race car design. I go into detail about how the systems engineering method works and how it can and should be applied to the way they design their car. 5. I then describe how the team should implement this method because the method is useless if they do not implement it into their design process. I include an interview from their brakes team leader, Colin Twist, to give an example of their current method of design and show how it can be improved with the new method. This paper provides a framework for the FSAE team to develop their new method of design that will help them accomplish their overall goal of succeeding at the national competition.
ContributorsPickrell, Trevor Charles (Author) / Trimble, Steven (Thesis director) / Middleton, James (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
This paper considers the state of desalination today and explores improvement of the reverse osmosis process via exergy analysis. Various methods of desalination in place today were explored, along with the proportion of each of those methods in use today. From literature reviews, it was found the reverse osmosis (RO) and multi-stage flash (MSF) desalination were the main methods of desalination in use today. Desalination is an energy intensive process and so this paper aimed to address this issue in three ways: by exploring various coupling with renewable energy sources, carrying out an exergy analysis on the MSF and RO processes, and finally exploring conceptual methods of interest. It was found that concentrated solar power was best suited for the MSF process, since the MSF process require direct heat. Wind energy was best suited for the RO process, since RO was less energy intensive and so could account for wind variability. The exergy analysis demonstrated very low second law efficiency for both desalination processes (~4%), with most of the exergy being destroyed in the separation process (~75%). The RO process also demonstrated a higher efficiency and lower exergy destruction, reinforcing the conlcusion that RO is the less energy intensive of the two. Based on the analysis, it was found throttling valves account for the next highest exergy destruction after the separation process. An alternate plant design was proposed to fully utilize wasted pressure, which resulted in less energy consumption. Finally, two conceptual methods, a mobile desalination plant and the Hybrid process, were explored that could potentially make the RO process a more valuable asset to society and more economically viable with a higher yield
ContributorsKotagama, Praveen Budhijith Bandara (Author) / Wells, Valana (Thesis director) / Miner, Mark (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05
Description
This thesis investigates the viability of a solar still for desalination of a personal water supply. The end goal of the project is to create a design that meets the output requirement while tailoring the components to focus on low cost so it would be feasible in the impoverished areas of the world. The primary requirement is an output of 3 liters of potable water per day, the minimum necessary for an adult human. The study examines the effect of several design parameters, such as the basin material, basin thickness, starting water depth, basin dimensions, cover material, cover angle, and cover thickness. A model for the performance of a solar still was created in MATLAB to simulate the system's behavior and sensitivity to these parameters. An instrumented prototype solar still demonstrated viability of the concept and provided data for validation of the MATLAB model.
ContributorsRasmussen, Dylan James (Author) / Wells, Valana (Thesis director) / Trimble, Steven (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor)
Created2015-05