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Description
Current prosthetic designs have limitations with properly representing the full range of motion that a human elbow provides. The structure of the biological elbow was analyzed to assess how it produces the flexion/extension and pronation/supination movement. The humerus and ulna have a hinge joint relationship, the humerus acts as a concave cylinder and the ulna acts as a convex cylinder, and the radius and ulna have a pivot joint relationship, the radius rotates around the ulna on a single axis. The joint cavity is responsible for flexion/extension and pronation/supination and also provides lubrication and strength of the elbow joint. A new design of a prosthetic elbow joint was created to mimic human elbow movements. The design uses a ball-and-socket socket joint that allows for flexion/extension and pronation/supination movement while incorporating a hydrogel lining to provide lubrication and restriction of pronation/supination to not go beyond human capacity. This joint was designed to be assembled from the back to the front; the socket has a cap on the outside that would allow for the ball to be inserted inside the socket and the cap be placed onto the socket. Once the final design and assembly process was completed, analysis of the design was performed to determine whether the design would be functional and reliable. The analysis concluded that the design and the material chosen for the design would not result in fracture and would also result in a large factor of safety, thus indicating that the prosthetic joint would not be easily damaged. Further research and development of this prosthetic elbow joint could be performed to allow it to be interchangeable with hinge joints that are currently used. Future work will include further research on the hydrogel lubricant, further analysis of the design and possible design modifications to allow for use in current practices and to account for the weak points in the current design. In summary, a successful redesign of the elbow joint prosthetic that provides low friction flexion/extension as well as pronation/supination movement will better serve the needs of individuals with amputation.
ContributorsHuffman, Randee Lee (Author) / James, Abbas (Thesis director) / David, Vowels (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The overall goal of this paper is to promote wellness, exercise and positive mental health. To encourage this goal, insight on the benefits of worksite wellness programs will be provided. Current worksite wellness programs focus minimally on the mental health benefits of exercise. Instead they focus on physiological results that come with worksite wellness programs. Exercise can provide both physiological and psychological health benefits (Ramirez & Wipfli, 2012). There should be more emphasis on mental health benefits of worksite wellness programs to provide positive mental health benefits in the workplace.
There are many different types of worksite wellness programs such as group fitness, on-site facilities and health allowances. It is important to vary wellness activities due to individuals having different fitness and health motivation. This implementation can become costly and require resources and support that many companies do not want to provide without successful results. Focusing on the psychological health benefits to such programs will allow companies to recognize the increase in productivity and positive work environment that result in worksite wellness programs. This will allow not only employees to benefit from the implementation of such programs but also the succession of the company.
This paper will explore ways to seek future enhancements within worksite wellness programs. Individuals will be given ways to positively contribute to work environments while maintaining healthy lifestyles. Companies will also better understand the importance that top recruits in the industry see within these types of programs. Through worksite wellness programs, employees will be provided with the tools necessary to improve their physical and mental health, while companies will have a more positive work environment as a result.
There are many different types of worksite wellness programs such as group fitness, on-site facilities and health allowances. It is important to vary wellness activities due to individuals having different fitness and health motivation. This implementation can become costly and require resources and support that many companies do not want to provide without successful results. Focusing on the psychological health benefits to such programs will allow companies to recognize the increase in productivity and positive work environment that result in worksite wellness programs. This will allow not only employees to benefit from the implementation of such programs but also the succession of the company.
This paper will explore ways to seek future enhancements within worksite wellness programs. Individuals will be given ways to positively contribute to work environments while maintaining healthy lifestyles. Companies will also better understand the importance that top recruits in the industry see within these types of programs. Through worksite wellness programs, employees will be provided with the tools necessary to improve their physical and mental health, while companies will have a more positive work environment as a result.
ContributorsJohnson, Sydney Rae (Author) / Hoffner, Kristin (Thesis director) / Marsit, Joseph (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This honors thesis explores and models the flow of air around a cylindrical arrow that is rotating as it moves through the air. This model represents the airflow around an archery arrow after it is released from the bow and rotates while it flies through the air. This situation is important in archery because an understanding of the airflow allows archers to predict the flight of the arrow. As a result, archers can improve their accuracy and ability to hit targets. However, not many computational fluid dynamic simulations modeling the airflow around a rotating archery arrow exist. This thesis attempts to further the understanding of the airflow around a rotating archery arrow by creating a mathematical model to numerically simulate the airflow around the arrow in the presence of this rotation. This thesis uses a linearized approximation of the Navier Stokes equations to model the airflow around the arrow and explains the reasoning for using this simplification of the fully nonlinear Navier Stokes equations. This thesis continues to describe the discretization of these linearized equations using the finite difference method and the boundary conditions used for these equations. A MATLAB code solves the resulting system of equations in order to obtain a numerical simulation of this airflow around the rotating arrow. The results of the simulation for each velocity component and the pressure distribution are displayed. This thesis then discusses the results of the simulation, and the MATLAB code is analyzed to verify the convergence of the solution. Appendix A includes the full MATLAB code used for the flow simulation. Finally, this thesis explains potential future research topics, ideas, and improvements to the code that can help further the understanding and create more realistic simulations of the airflow around a flying archery arrow.
ContributorsCholinski, Christopher John (Author) / Tang, Wenbo (Thesis director) / Herrmann, Marcus (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This experiment analyzed the degradation mechanisms in polymer matrix composite (PMC) samples after more than 50 years of simulated exposure to hygrothermal conditioning. This strong, form-adaptive, lightweight material is suitable for use on critical structures including nuclear powerplants and spacecrafts as primary reinforcers to improve fracture toughness. Current literature regarding PMC material has a poor understanding of its delamination trends and varying interphase properties that determine its overall reliability under extreme weather conditions. This paper will evaluate the long-term impact from exposure to heat and humidity regarding the material’s stiffness and degradation to confirm PMC’s reliability for use in structures that undergo these conditions. To study this phenomenon, aged and unaged PMC samples were analyzed on the nanoscale using PeakForce Quantitative Nanomechanical mode (PF-QNM) of Atomic Force Microscopy with an indentation tip no greater than 10nm in radius. This paper compares this testing method to the results from recent research on other microscopy modes to discuss the validity of the PF-QNM model as it is used for this analysis. The data obtained allowed for analysis of crack propagation and quantification of strength in interphase between the composite’s constituents. This research verifies the testing method for which a comprehensive understanding of the environmental influences on PMC mechanical properties could be achieved.
ContributorsTotillo, Anita (Co-author, Co-author) / Yekani Fard, Masoud (Thesis director) / Patel, Jay (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This paper discusses the possibility of utilizing 2D molybdenum disulfide (MoS2) as a nanozyme to detect dopamine colorimetric assays, first by detecting color change in liquid solutions due to oxidation and then second on paper-based assays. MoS2 samples dispersed in methylcellulose (MC) solution were prepared using liquid-phase exfoliation through sonication. The dopamine (DOPA) and hydrogen peroxide (H¬¬2O2) solutions were prepared separately in specific concentrations. The solutions were mixed in a well plate and colorimetric results were analyzed by a plate reader, revealing a quantitative relationship between dopamine concentration and absorbance. Subsequent testing was conducted using paper assays, where combined solutions of DOPA and H2O2 were dropped onto paper with printed wax wells that contained dried MoS2. An analysis of the color change was conducted using a smartphone application called Color Grab to detect the red, green, and blue (RGB) values. Plotting the RGB results across the dopamine concentrations revealed a positively correlated relationship between the two factors, suggesting that a predictive model could be developed to predict dopamine concentrations based on measured colorimetric values.
ContributorsNalla, Akshay (Co-author, Co-author) / Wang, Qing Hua (Thesis director) / Green, Alexander (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Smallsats such as CubeSats have a variety of growing applications in low Earth orbit (LEO), near Earth orbit (NEO), and deep space environments across communications, imaging, and more. Such applications have tight pointing requirements and thus an accompanying need for attitude control systems (ACS) with finer pointing capabilities and longer lifetimes. Current systems such as magnetorquers and reaction wheels have notable limitations. Magnetorquers lose applicability for many deep space applications while the latter is dependent on moving components and cannot be operated independently due to momentum saturation among other limitations. Micro-Pulsed Plasma Thrusters (μPPTs) can be designed for multi-axis control in space. The use of solid Teflon (PTFE) propellant to produce a controllably small impulse within the thrusters can enable increased fine pointing accuracy and precision. In this paper, a preliminary design of an 8-thruster set of breech-fed μPPTs is analyzed through mechanical simulation tools to address challenges posed by miniaturization into a 1U module. Mechanical challenges of miniaturizing a μPPT module are particularly driven by the volume constraint and the associated appropriate mass. Thermal analysis performed using C&R Thermal Desktop, addresses the thermal environment for various use cases, individual component heating, as well as heat transfer through the module. This directly informs component layout recommendations and thermal controls based upon maintaining operational temperature ranges for various use cases. This model as well as fabrication considerations inform material selections for various structures in the preliminary μPPT design. In this paper I will discuss the overall design of the PPT model that has been configured here at Arizona State University by the Sun Devil Satellite Laboratory. I will then discuss the findings of my thermal analysis that was performed using Thermal Desktop.
ContributorsArnest, Dylan (Author) / Benson, David (Thesis director) / Acuna, Antonio (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Wastewater treatment plant (WWTP) utilization of combined heat and power (CHP) systems allows for the efficient use of on-site biogas production, as well as increased annual savings in utility costs. In this thesis, a literature review of six CHP prime mover technologies is presented. Even though there are different prime mover technologies, the main ones currently being implemented in WWTPs are micro turbines, fuel cells and reciprocating engines. These prime mover technologies offer varying efficiencies, installation costs and maintenance requirements. The prime movers are also all in different stages of development, leading some to be more currently-in-use than others in WWTPs. Currently reciprocating engines and micro turbines occupy the largest shares of the CHP in WWTP sector.
This thesis will also go in detail into equations and calculations created for a techno-economic assessment for installation and maintenance of a CHP system at a WWTP. The equations and calculations created here were then utilized with data from a typical WWTP in the Southwestern United States to create an accurate case study. In this case study, a payback of 5.7 years and a net present value of $709,000 can be achieved when the WWTP generates over 2,000,000 m3 of biogas per year and utilizes over 36,000 GJ of natural gas per year.
This thesis will also go in detail into equations and calculations created for a techno-economic assessment for installation and maintenance of a CHP system at a WWTP. The equations and calculations created here were then utilized with data from a typical WWTP in the Southwestern United States to create an accurate case study. In this case study, a payback of 5.7 years and a net present value of $709,000 can be achieved when the WWTP generates over 2,000,000 m3 of biogas per year and utilizes over 36,000 GJ of natural gas per year.
ContributorsRiley, Derall (Author) / Milcarek, Ryan (Thesis director) / Villalobos, Rene (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
The dynamics of friction as they relate to automobile behavior have been heavily analyzed under conditions that are favorable and predictable in the realm of daily driving. The scope of this project is to investigate behavior of slip in unfavorable conditions and develop a mathematical solution that allows users to predict behavior of oversteer and excessive sideslip. I am fascinated by the topic as I have developed a background in the sport of drifting (controlled oversteer) and would like to contribute to the understanding of this lesser appreciated science. Highly valued components of the project such as velocities, forces, coefficients of friction, steering angles, slip angles, and multi-wheel analysis will all lead to a deeper understanding of relationships between aspects of a vehicle undergoing oversteer.
ContributorsRoden, Michael (Author) / Takahashi, Timothy (Thesis director) / Murthy, Raghavendra (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The dynamics of friction as they relate to automobile behavior have been heavily analyzed under conditions that are favorable and predictable in the realm of daily driving. The scope of this project is to investigate behavior of slip in unfavorable conditions and develop a mathematical solution that allows users to predict behavior of oversteer and excessive sideslip. I am fascinated by the topic as I have developed a background in the sport of drifting (controlled oversteer) and would like to contribute to the understanding of this lesser appreciated science. Highly valued components of the project such as velocities, forces, coefficients of friction, steering angles, slip angles, and multi-wheel analysis will all lead to a deeper understanding of relationships between aspects of a vehicle undergoing oversteer.
ContributorsRoden, Michael Joseph (Author) / Takahashi, Timothy (Thesis director) / Murthy, Raghavendra (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
Due to the Human foot constantly growing at a rapid pace, typical gel and mold orthotics quickly become ineffective as they no longer fit the foot properly. In pediatric patients, this situation is even more pronounced as their feet change geometry at an even more rapid rate. This project consists of designing an adjustable sizing Pediatric Orthotic for use in children as well as adult patient’s shoes to provide better foot support than not using one at all, or for that matter an inappropriately sized orthotic. This idea incorporates multiple air bladders that can hold pressure and adjust shape as is necessary to best accommodate the patient’s foot geometry to reduce the deformation and average stress presented within the foot. Results will be obtained by running simulation models of these phenomena in MATLAB as well as Ansys softwares. From the results, by incorporating two bladders into the middle arch of a ‘control’ patient who has a perfectly symmetric arch, maximum deformation of the foot was reduced by approximately 17%. Under this same scenario, average stress in the foot dropped by approximately 13%. In a more abnormal ‘experimental’ case, of a largely asymmetric arch, it was found that max deformation and average stress in the foot dropped by 21% and 17% respectively. This leads to the conclusion that incorporating this design will indeed lower the stress and fulfill the requirement of an orthotic while also being a removable and adjustable air bladder to fulfill the adjustability constraint.
ContributorsNaqvi, Abbas Ali (Author) / Benson, David (Thesis director) / Murthy, Raghavendra (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12