Mechanical Engineering Commons^™

Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe

Honors Theses

Traditional ankle-foot prostheses often replicate the physiological change in shape of the foot during gait via compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Multi-segment rigid-body devices offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without prior accounting of the complex internal kinetics of the foot. This work focuses on applying …

Improving Electrochemical Devices Via Increased Charge Density And Ceramic Nanoparticles, George Padavick

Honors Theses

Challenges posed by climate change in conjunction with increasing global energy demand necessitate improved energy systems in both transportation and power delivery. These systems will require more advanced energy storage than current commercially available options. To enhance energy storage capabilities, supercapacitors were investigated to discover new mechanisms, materials, and fabrication techniques for developing electrochemical devices. In particular, methods for improving electrolyte performance were explored to enhance capacitance and conductivity. The results indicate that increasing charge density in the electrolyte via higher salt concentration or higher ionic charge of the solvated ions significantly increases capacitance. Specifically, a 0.1M solution of magnesium …

Design And Prototyping Of A Shape-Changing Rigid-Body Human Foot In Gait, Tanner N. Rolfe

Honors Theses

Traditional ankle-foot prostheses often replicate the physiological change in shape of the foot during gait via compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Multi-segment rigid-body devices offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without prior accounting of the complex internal kinetics of the foot. This work focuses on applying …

Next Steps For Mentoring Program, Patrick Gray

Sustainability and Connectivity

This file provides a jump-off position for students in the fall 2017 semester who want to continue work toward a mentoring program.

Biomass Cookstoves: An Empirical Study Into The Relationship Between Thermal Efficiency And Tending Practices For The Developing World, Erin Peiffer

Honors Theses

More than 2 billion people in the world use biomass stoves for cooking and heating their homes. Due to incomplete combustion, toxic byproducts such as soot, nitrous oxides and carbon monoxide gasses form. These toxic substances contribute to pollution and can lead to serious health issues over time if inhaled leading to approximately 4 million premature deaths each year. The formation of these toxic substances can be mitigated, in part, through the introduction of increased turbulence intensity allowing for the so-called “well-stirred combustion regime”. Here we will be exploring the health, environmental, and social effects of biomass combustion in the …

Design Of An Opposed-Piston, Opposed-Stroke Diesel Engine For Use In Utility Aircraft, Luke Kozal

Honors Theses

The objective of this thesis was to determine the feasibility of using an opposed-piston, opposed-stroke, diesel engine in utility aircraft. Utility aircraft are aircraft that have a maximal takeoff weight of 12,500lbs. These aircraft are often used for transportation of cargo and other goods. In order to handle that weight, many of the aircraft are powered by turboprop engines. Turboprop engines are a style of jet engine with power capabilities ranging from 500 to several thousand horsepower (hp). They are expensive engines, and in the case of the Piper Mirage, substituting the piston engine with a turboprop engine can increase …

Project Plan - Mentoring, Abigail Lisjak, Patrick Gray, Timothy Leonard, Adam Foster

Sustainability and Connectivity

A presentation that includes the ideal goal for the project as well as how the project can relate to the other projects in the class.

Mentoring Initial Research, Abigail Lisjak, Tim Leonard, Adam Foster, Patrick Gray

Sustainability and Connectivity

This document details the initial research the group gathered as the problem statement was being refined. Some of this research will be used to inform future elements of the project.

Special Issue: Selected Papers From Idetc 2015, Venkat N. Krovi, Andrew P. Murray, James Schmiedeler

Mechanical and Aerospace Engineering Faculty Publications

This second IDETC Special Issue, containing 19 papers from researchers in seven countries on three continents, seeks to cap- ture the current interest topics and latest results from the 39th ASME Mechanisms and Robotics (M&R) conference. The topics span the synthesis and analysis of novel mechanisms and robots as well as their validation in a variety of applications. The papers are organized with contributions to the core theoretical methodol- ogies of M&R (five papers) appearing first. The application areas that follow are micro air vehicles (MAVs) (two papers), modular robotics (three papers), origami applications (three papers), medi- cal robotics (three …

Simulation Model Of An Automatic Commercial Ice Machine, Haithem Murgham, David Myszka, Vijay Bahel, Rajan Rajendran, Kurt Knapke, Suresh Shivashankar, Kyaw Wynn

Mechanical and Aerospace Engineering Faculty Publications

Automatic commercial ice-making machines that produce a batch of cube ice at regular intervals are known as “cubers." Such machines are commonly used in food service, food preservation, hotel, and health service industries. The machines are typically rated for the weight of ice produced over a 24-hour period at ambient air temperatures of 90°F and water inlet temperature of 70°F.

These cubers typically utilize an air-cooled, vapor-compression cycle to freeze circulating water flowing over an evaporator grid. Once a sufficient amount ice is formed, a valve switches to enable a harvest mode, where the compressor’s discharge gas is routed into …

Phosphorus Adsorption Through Engineered Biochars Produced From Local Waste Products, Peter Ogonek

Honors Theses

Phosphorus contained in agricultural runoff is a major anthropogenic contributor to harmful algal blooms (HABs). Biochars are carbon-based materials produced from the pyrolysis of waste biomass that have the potential to amend soils and remediate inorganic and organic contaminants from water. Engineered biochars tailored to adsorb phosphorus from water could reduce the availability of the nutrient in agricultural runoff, reducing the size and frequency of HABs. This study observed the phosphorus adsorption properties of engineered biochars produced from two source materials, oak sawdust and cornstalk residue, and being unmodified, acid-rinsed, or loaded with magnesium prior to pyrolysis, creating acid-rinsed, unmodified, …

Design And Prototyping Of A Variable Geometry Extrusion Die To Exhibit Significant Alteration Of Shape, David C. Bell

Honors Theses

Extruded parts are conventionally made by forcing melted plastic through a steel die having a fixed opening that matches the shape of the part. Plastic parts made by extrusion include weather stripping, PVC pipe, and composite lumber. Variable geometry dies can change their opening shape during the extrusion process. Developing shape-changing dies technology offers the possibility of making parts with varying cross-sections that currently need to be made through injection molding. This is desirable as, compared to molding, extrusion tends to be faster and less expensive. Variable geometry extrusion dies have been designed and prototyped by the University of Dayton …

Nonlinear Analysis Of Balance Data In The Easter Seals Adult Day Services Population, Taylor Marie Schemmel

Honors Theses

81.1 million adults are expected to be affected by dementia in 2040. Individuals with dementia are twice as likely to fall as healthy individuals and three times as likely to sustain an injury during a fall. Unfortunately, current fall prevention techniques in place for cognitively healthy older adults are not as effective for those with dementia. The objective of this study was to examine balance differences between individuals of varying cognitive ability utilizing Easter Seals Adult Day Services. All study participants completed the Montreal Cognitive Assessment (MoCA). Clinical assessments were done in conjunction with static posturography data collection on a …

Evaluation Of Different Optimal Control Problem Formulations For Solving The Muscle Redundancy Problem, Friedl De Groote, Allison Kinney, Anil Rao, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

This study evaluates several possible optimal control problem formulations for solving the muscle redundancy problem with the goal of identifying the most efficient and robust formulation. One novel formulation involves the introduction of additional controls that equal the time derivative of the states, resulting in very simple dynamic equations. The nonlinear equations describing muscle dynamics are then imposed as algebraic constraints in their implicit form, simplifying their evaluation. By comparing different problem formulations for computing muscle controls that can reproduce inverse dynamic joint torques during gait, we demonstrate the efficiency and robustness of the proposed novel formulation.

Wing Tip Vortices From An Exergy-Based Perspective, Muhammad Omar Memon, Kevin Wabick, Aaron Altman, Rainer M. Buffo

Mechanical and Aerospace Engineering Faculty Publications

The lens of exergy is used to investigate a wingtip vortex in the near wake over a range of angles of attack. Exergy is the measure of thermodynamically “available” energy as determined through the more discriminating second law of thermodynamics. Experiments were conducted in a water tunnel at Institute of Aerospace Systems at Aachen.

The data were taken three chord lengths downstream in the Trefftz plane of an aspect ratio 5 Clark-Y wing with a square-edged wing tip using particle image velocimetry. Intuitively, the minimum available energy state is expected to correspond to the maximum lift-to-drag ratio angle of attack. …

Development Of A Muscle Model Parameter Calibration Method Via Passive Muscle Force Minimization, Allison Kinney, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Computational predictions of subject-specific muscle and knee joint contact forces during walking may improve individual rehabilitation treatment design. Such predictions depend directly on specified model parameter values. However, model parameters are difficult to measure non-invasively. Methods for muscle model parameter calibration have been developed previously. However, it is currently unknown how the musculoskeletal system chooses muscle model parameter values. Previous studies have hypothesized that muscles avoid injury during walking by generating little passive force and operating in the ascending region of the force-length curve. This hypothesis suggests that muscle model parameter values may be selected by the body to minimize …

Synergy-Based Two-Level Optimization For Predicting Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Josep M. Font-Llagunes, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Musculoskeletal models and optimization methods are combined to calculate muscle forces. Some model parameters cannot be experimentally measured due to the invasiveness, such as the muscle moment arms or the muscle and tendon lengths. Moreover, other parameters used in the optimization, such as the muscle synergy components, can be also unknown. The estimation of all these parameters needs to be validated to obtain physiologically consistent results. In this study, a two-step optimization problem was formulated to predict both muscle and knee contact forces of a subject wearing an instrumented knee prosthesis. In the outer level, muscle parameters were calibrated, whereas …

Hydrogen And Syngas Production From Gasification Of Lignocellulosic Biomass In Supercritical Water Media, Jun-Ki Choi, Abtin Ataei, Ahmad Tavasoli, Farid Safari

Mechanical and Aerospace Engineering Faculty Publications

Novel biomass-processing technologies have been recently used for conversion of organic wastes into valuable biofuels like bio-hydrogen. Agricultural wastes are available and renewable energy resources to supply energy demand of the future. The purpose of this study is to investigate the production of hydrogen-rich syngas from wheat straw, walnut shell, and almond shell.

The Influence Of Neuromusculoskeletal Model Calibration Method On Predicted Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

This study explored the influence of three model calibration methods on predicted knee contact and leg muscle forces during walking. Static optimization was used to calculate muscle activations for all three methods. Approach A used muscle-tendon model parameter values (i.e., optimal muscle fiber lengths and tendon slack lengths) taken directly from literature. Approach B used a simple algorithm to calibrate muscle-tendon model parameter values such that each muscle operated within the ascending region of its normalized force-length curve. Approach C used a novel two-level optimization procedure to calibrate muscle-tendon, moment arm, and neural control model parameter values while simultaneously predicting …

Intrusion Detection In Aerial Imagery For Protecting Pipeline Infrastructure, Paheding Sidike, Almabrok Essa, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

We present an automated mechanism that can detect and issue warnings of machinery threat such as the presence of construction vehicles on pipeline right-of-way. The proposed scheme models the human visual perception concepts to extract fine details of objects by utilizing the corners and gradient histogram information in pyramid levels. Two real-world aerial image datasets are used for testing and evaluation.

School-Books On Tape: The Tensile And Adhesive Strength Of Duct Tape In A College Backpack, Robin Elizabeth Ker

Honors Theses

Two categories were used to assess the strength of duct tape constructions: adhesive strength and tensile strength. Previously made duct tape backpacks frequently suffered from adhesive failure around shoulder straps. When a backpack is lifted, it experiences a force which is greater than the resting weight. The hypothesis states that there is an area of application between two pieces of duct tape such that they will behave as a uniform piece and experience tensile failure, that two sufficiently overlapped pieces can hold within 5% of the load carried by a single piece, and that there is a relationship between the …

Multi-Segment Foot Joint Kinematics With Varying Midfoot Orthotic Postings, Hilary F. Feskanin

Honors Theses

Foot orthoses are often prescribed to prevent and treat lower limb disorders. While the success of these devices is well documented, the mechanisms behind them are unclear. Due to methodological limitations, many studies have focused on the rearfoot. This is the first study to assess the effects of midfoot-targeted orthotic strategies on midfoot and rearfoot kinematics. Gait mechanics were recorded for 19 healthy females walking in four orthotic conditions: valgus midfoot post, varus midfoot post, heel lift and standard/control. The midtarsal and ankle joint 3D kinematics for the three experimental conditions were compared to the control condition. Variables of interest …

A Mechanical Regenerative Brake And Launch Assist Using An Open Differential And Elastic Energy Storage, David H. Myszka, Andrew P. Murray, Kevin Giaier, Vijay Krishna Jayaprakash, Christoph Gillum

Mechanical and Aerospace Engineering Faculty Publications

Regenerative brake and launch assist (RBLA) systems are used to capture kinetic energy while a vehicle decelerates and subsequently use that stored energy to assist propulsion. Commercially available hybrid vehicles use generators, batteries and motors to electrically implement RBLA systems. Substantial increases in vehicle efficiency have been widely cited.

This paper presents the development of a mechanical RBLA that stores energy in an elastic medium. An open differential is coupled with a variable transmission to store and release energy to an axle that principally rotates in a single direction. The concept applies regenerative braking technology to conventional automobiles equipped with …

Simulating Energy Efficient Control Of Multiple-Compressor Compressed Air Systems, Sean Murphy, J. Kelly Kissock

Mechanical and Aerospace Engineering Faculty Publications

In many industrial facilities it is common for more than one air compressor to be operating simultaneously to meet the compressed air demand. The individual compressor set-points and how these compressors interact and respond to the facility demand have a significant impact on the compressed air system total power consumption and efficiency. In the past, compressors were staged by cascading the pressure band of each compressor in the system. Modern automatic sequencers now allow more intelligent and efficient staging of air compressors.

AirSim, a compressed air simulation tool, is now able to simulate multiple-compressor systems with pressure band and automatic …

A Multi-Directional Treadmill Training Program For Improving Gait, Balance, And Mobility In Individuals With Parkinson’S Disease: A Case Series, Kimberly Smith, Kurt Jackson, Kimberly Edginton Bigelow, Lloyd L. Laubach

Mechanical and Aerospace Engineering Faculty Publications

Treadmill training is a commonly used intervention for improving gait in people with Parkinson’s disease (PD). However, little is known about how treadmill training may also influence balance and other aspects of mobility.

The purpose of this case series was to explore the feasibility and possible benefits of multi-directional treadmill training for individuals with PD. Four participants (62.3 ± 6.5 yrs, Hoehn & Yahr 2-4) performed 8 weeks of treadmill training 3 times per week. Weeks 1-4 included forward walking only, while weeks 5-8 included forward and multi-directional walking. Participants were tested every 4 weeks on 4 separate occasions. Outcome …

Leveraging Students’ Passion And Creativity: Ethos At The University Of Dayton, Margaret Pinnell, Malcolm Daniels, Kevin P. Hallinan, Gretchen Berkemeier

Mechanical and Aerospace Engineering Faculty Publications

The Engineers in Technical Humanitarian Opportunities of Service-learning (ETHOS) program was developed in the spring of 2001 by an interdisciplinary group (electrical, chemical, civil and mechanical) of undergraduate engineering students at the University of Dayton (UD). ETHOS was founded on the belief that engineers are more apt and capable to appropriately serve our world if they have an understanding of technology’s global linkage with values, culture, society, politics, and the economy. Since 2001, the ETHOS program at UD has grown and changed.

From conceptualization, to implementation, to maturation and national recognition, the program has addressed challenges of academic acceptance, programmatic …

Deltoid Moment Arms During Abduction: A Subject-Specific Musculoskeletal Modeling Study In Healthy Shoulders And Shoulders With Rtsa, David Walker, Allison Kinney, Aimee Struk, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

Reverse total shoulder arthroplasty (RTSA) is increasingly used in the United States since approval by the FDA in 2003. RTSA relieves pain and restores mobility in arthritic rotator cuff deficient shoulders. Though many advantages of RTSA have been demonstrated, there still are a variety of complications (implant loosening, shoulder impingement, infection, frozen shoulder) making apparent much still is to be learned how RTSA modifies normal shoulder function. The goal of this study was to assess how RTSA affects deltoid muscle moment generating capacity post-surgery using a subjectspecific computational model driven by in vivo kinematic data.

How Sensitive Is The Deltoid Moment Arm To Joint Center Changes With Rtsa?, David Walker, Allison Kinney, Aimee Struk, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

The goal of this study was to assess the sensitivity of the deltoid muscle moment arms as a function of joint configuration for an existing RTSA subject. High variations were found for all three deltoid components. Variation over the entire abduction arc was greatest in the anterior and lateral deltoid, while the posterior deltoid moment arm was mostly sensitive to joint center changes early in the abduction arc. Moment arm changes of 10-16mm represent a significant amount of the total deltoid moment arm. This means there is an opportunity to dramatically change the deltoid moments arms through surgical placement of …

A Novel Approach To Estimation Of Patient-Specific Muscle Strength, David Walker, Allison Kinney, Benjamin J. Fregly, Thomas Wright, Scott Banks

Mechanical and Aerospace Engineering Faculty Publications

Current modeling techniques have been used to model the Reverse Total Shoulder Arthroplasty (RTSA) to account for the geometric changes implemented after RTSA. Though these models have provided insight into the effects of geometric changes from RTSA these is still a limitation of understanding muscle function after RTSA on a patient-specific basis. The goal of this study sought to overcome this limitation by developing an approach to calibrate patient-specific muscle strength for an RTSA subject.

Transit As An Alternative Mode Of Transportation: A Case Study Of Its Usage, Availability, Patterns And Value For Non-Commuter Trips, Sara Hardman

Honors Theses

The mode of transportation a user picks impacts the environment, the social environment, and the user himself/herself. While research on alternative modes of transportation is prevalent in both the engineering and sociology fields, little attention has been given to the choices people make concerning how they run errands and other social trips, focusing instead on commuter trips. This case study examines three different shopping malls and the surrounding bus stops in order to determine the role distance plays in bus usage and the value that shopping centers place on access to local bus routes. Determination of the value and potential …