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 …

Rapid Characterization Of Local Shape Memory Properties Through Indentation, Peizhen Li, Haluk E. Karaca, Yang-Tse Cheng

Mechanical Engineering Faculty Publications

Shape memory alloys (SMAs) have the ability to show large recoverable shape changes upon temperature, stress or magnetic field cycling. Their shape memory, material and magnetic properties (e.g. transformation temperatures, strain, saturation magnetization and strength) determine their prospects for applications from small-scale microelectromechanical systems to large scale aerospace and biomedical systems. It should be noted that properties of SMAs are highly temperature dependent. Generally, the conventional mechanical characterization methods (e.g, tension, compression, and torsion) are used on bulk samples of SMAs to determine those properties. In this article, it will be shown that indentation technique can be used as an …

Optical Properties Of Organic Carbon And Soot Produced In An Inverse Diffusion Flame, C. Russo, B. Apicella, J. S. Lighty, A. Ciajolo, A. Tregrossi

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The carbonaceous matter (soot plus organic carbon) sampled downstream of an ethylene inverse diffusion flame (IDF) was chemically and spectroscopically analyzed in detail. In particular, the H/C ratio, the UV-Visible absorption coefficient and Raman parameters were measured and found to be representative of a highly disordered sp² -rich carbon as the early soot sampled in a premixed flame. In contrast, the optical band gap was found to be relatively low (0.7eV), closer to the optical band gap of graphite than to that of medium-sized polycyclic aromatic hydrocarbons (>2eV) which are widely considered to be soot precursors and are …

Highly Compressible Origami Bellows For Harsh Environments, Jared J. Butler

Theses and Dissertations

The use of origami-based bellows is of interest in fields where traditional metal bellows are incapable of meeting compression, mass, or flexibility constraints. Metal bellows are often used in space applications but frequently complicate spacecraft design. Origami-based bellows capable of meeting design constraints while adequately shielding sensitive spacecraft parts may be advantageous to space mechanism design. The design and testing of a highly compressible origami bellows for harsh environments is described. Several origami patterns were evaluated and the Kresling fold pattern was designed to meet constraints and selected for use in the bellows design. Origami bellows were prototyped in five …

Animated Otto-Langen Atmospheric Engine, Keiran M. Hansen, Lance Hodgson, Rachel A. Jakob, Chris J. Splees

Mechanical Engineering

Based on an existing relationship between Dr. Owen and the Deutsches Museum, Otto-Mated was given the opportunity to collaborate with the two in a year-long senior design project. Otto-Mated was tasked with modeling and simulating the Otto-Langen Atmospheric Engine as a form of preservation and education. The model was created in SolidWorks and animated in Blender, effectively providing the museum with accurate and educational videos demonstrating the engine’s function. Within this document are the plans, decisions, and processes used to create our final product for Deutsches Museum.

Experimental Investigations Of Techniques To Enhance The Cooling Rate Of Hot Fluids By Utilizing Gallium As A Heat Sink Material, Abdallah M. S. Ghazal

Mechanical Engineering Theses

No abstract provided.

Developing New Classes Of Thick-Origami-Based Mechanisms: Conceal-And-Reveal Motion And Folding Printed Circuit Boards, Bryce Parker De Figueiredo

Theses and Dissertations

Origami-adapted mechanisms form the basis of an increasing number of engineered systems. As most of these systems require the use of non-paper materials, various methods for accommodating thickness have been developed. These methods have opened new avenues for origami-based design. This work introduces approaches for the design of two new classes of thick-origami systems and demonstrates the approaches in hardware. One type of system, called "conceal-and-reveal,'' is introduced, and a method of designing these mechanisms is developed. Techniques are also developed for designing folding printed circuit boards which are fabricated from a single sheet of material. This enables areas of …

Polyethylene Oxide—Fullerene Nanocomposites, Nasar Ali, Dorina M. Chipara, Karen Lozano, James R. Hinthorne, Mircea Chipara

Mechanical Engineering Faculty Publications

Polyethylene oxide – fullerene nanocomposites have been prepared by using the solution path with water as solvent (only for the polymer). The dispersion of C60 within the polymer solution was achieved by high power sonication. The study aims to a better understanding on the effect of C60 nanoparticles on the macromolecular chains. Raman Wide Angle X Ray spectroscopy, Differential Scanning Calorimetry, and Thermogravimetric Analysis were used to inspect the interactions between the nanofiller and macromolecular chains. The experimental results revealed a completely different behavior of fullerene dispersed within polymeric matrices than using carbon nanotubes or nanofibers as nanofiller. …

Distributed Manufacturing Of Flexible Products: Technical Feasibility And Economic Viability, Aubrey Woern, Joshua M. Pearce

Department of Materials Science and Engineering Publications

Distributed manufacturing even at the household level is now well established with the combined use of open source designs and self-replicating rapid prototyper (RepRap) 3-D printers. Previous work has shown substantial economic consumer benefits for producing their own polymer products. Now flexible filaments are available at roughly 3-times the cost of more conventional 3-D printing materials. To provide some insight into the potential for flexible filament to be both technically feasible and economically viable for distributed digital manufacturing at the consumer level this study investigates 20 common flexible household products. The 3-D printed products were quantified by print time, electrical …

Application Of Surface Treatments To Improve Fuel Efficiency Of Internal Combustion Engines, Amirabbas Akbarzadeh

LSU Master's Theses

To improve the tribological performance of contacting surfaces, different surface modification methods can be employed. Surface texturing and surface coating are examples of viable techniques developed for this purpose. Surface texturing involves creating micropatterns on the contacting surfaces while surface coating requires depositing a thin layer of a suitable material on the surface(s) to improve the component’s friction and wear characteristics. The performance of textured surfaces is affected by the geometric characteristic of textures.When dealing with surface coating parameters, the parameters of interests are the type of coating materials and their thicknesses.

The current study aims to experimentally study the …

Measurement Of Speed Of Sound Profile Using Laaces Balloon, Zhuang Li, Brett Schaefer, Brian Schaefer, William Dever, Tyler Morgan, Matthew Foltz

2017 Academic High Altitude Conference

The goal of this mission is to test the speed of sound at different altitudes and ultimately at a maximum height of 100,000 feet (30 km). In conjunction with this testing, environmental parameters including temperature, pressure, and humidity are measured and used to calculate the speed of sound to compare to the measured results. The team constructed the payload “Dorothy” using polystyrene foam due to its lightweight and thermal isolation property. An ultrasonic sensor with a reflection mirror were installed outside payload box to measure speed of sound. All the sensors were calibrated. Software for the project was developed in …

Electric Charge Capacity And Breakdown Voltage Of Martian Simulant By Using Electro Dynamic Balance, Sakurako Kuba

Von Braun Symposium Student Posters

No abstract provided.

Predicting Mechanical Properties Of Lattice Structures, Behzad Bahrami Babamiri

Von Braun Symposium Student Posters

No abstract provided.

How Spaceflight Affects The Detachment Of Zinc Whiskers, Kayla Capitan

Von Braun Symposium Student Posters

No abstract provided.

A Vertical Axis Rotor For Wave Energy Conversion, Yingchen Yang, Joab Soto, Francisco Salazar

Mechanical Engineering Faculty Publications

The present work augments vertical-axis unidirectional wave energy converter (WEC) designs with a new approach. The enabling technique is the hydrodynamic design of a special rotor, which consists of a series of uniquely shaped blades in a certain formation. Specifically, individual blades are realized by revolving a two-dimensional symmetric hydrofoil about its chord line. Then the blades are arranged around a vertical shaft in a desired formation to form the rotor. When driven by an approaching flow through interaction, the rotor naturally rotates about the vertical shaft in a predefined direction. The approaching flow could be from any spatial direction, …

Semi-Annual Program Progress Performance Report For University Transportation Systems Pppr#8, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

The major activity of the past reporting period has been the completing of the final project research reports. During the period, twelve projects (numbers 3, 7, 10, 14, 17, 9, 22, 4, 5, 13, 20 and 18) were completed and the final project reports forwarded to DOT and the required associated organizations. Two additional final reports (numbers 12 and 21) are close to being completed. Final reports for the other 4 remaining projects (numbers 2, 8, 11 and 15) are in various stages of completion. For this reporting period, EVTC researchers concluded 12 project final reports, authored one publication, made …

Answering Food Insecurity: Serving The Community With Food And Knowledge Using Technology, Courtney Simpson

Purdue Journal of Service-Learning and International Engagement

The courses of Tech120, CGT110, and ENGT 180/181 and Red Gold at Purdue collaborated to design a robot that would plant and water a garden for a local community charter school. The students centered the project on the users’ needs for fresh food, nutrition education, and early exposure to STEM for children. The school, Anderson Preparatory Academy (APA), is comprised of many children who come from low-income families and are in the free or reduced lunch program. Inspired from “Farm Bot,” a similar system that allows for almost hands-free gardening, the “Boiler Bot” is designed to be scalable so children …

Cam-Based Pose-Independent Counterweighting For Partial Body-Weight Support In Rehabilitation, Ashish Shinde

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This thesis presents the design and testing of a body weight support system for gait training in a two-dimensional workspace. Extension of the system to a three-dimensional workspace is not within the scope of this thesis.

Gait dysfunctions are changes in normal walking patterns, often related to a disease or abnormality in different areas of the body. There are numerous body weight support (BWS) systems present in the market which are applied to rehabilitation scenarios in mobility recovery like in gait training. But most of these BWE systems are costly and generally are stationary devices. A major drawback of such …

Additional Data Via Autonomous Systems To Supplement Traditional Sparse Sources For Weather Forecasting And Atmospheric Science, Suzanne Weaver Smith

Commonwealth Computational Summit

No abstract provided.

The Effect Of Inlet Pulsations On Primary Atomization Of Liquid Jets, Kyle Windland, Prashant Khare

Commonwealth Computational Summit

Objectives

• Elucidate the physics underlying the primary atomization of liquid jets.
• Investigate the effect of inlet pulsations on the atomization process.
• Identify the reliability of numerical predictions using uncertainty quantification techniques (UQ) and sensitivity analyses.

High-Fidelity Simulations Of Water Jet In Air Crossflow, Austin Johnston, Prashant Khare

Commonwealth Computational Summit

Objectives

• Investigate detailed physics underlying liquid jets in crossflow configurations applicable to various applications such as, gas-turbine, scramjet, and afterburner fuel injection.
• Develop models to predict the statistical behaviors of resulting droplets.

Long-Term Cell Testing Of Interlayer-Free Lanthanum Strontium Cobalt Ferrite Cathodes For Solid Oxide Fuel Cells, Gianfranco Digiuseppe, Venkatesh Boddapati, Hiten Mothikhana

Mechanical Engineering Publications

Sub-stoichiometric LSCF nanopowders with composition of (La0.6Sr0.40)0.95Co0.2Fe0.80O3-d were prepared using a nitrate-glycine process. The particle size is estimated to be 28.8 nm using the Scherrer equation. A sintering study and pull test was done to determine the quality of LSCF adhesion to the YSZ electrolyte. It was found that firing the cathode at 850oC does not provide the best adhesion, but button cell testing data indicate that the performance is stable over relatively long-term tests. The cell performance is not up to par to state-of-the-art Ni-YSZ/YSZ/SDC/LSCF where a barrier layer is used and the cathode is fired at high temperatures. …

The Aspergillus Flavus Homeobox Gene, Hbx1, Is Required For Development And Aflatoxin Production, Jeffrey W. Cary, Pamela Y. Harris-Coward, Leslie Scharfenstein, Brian M. Mack, Perng-Kuang Chang, Qijian Wei, Matthew Lebar, Carol Carter-Wientjes, Rajtilak Majumdar, Chandrani Mitra, Sourav Banerjee, Anindya Chanda

Faculty Publications

Homeobox proteins, a class of well conserved transcription factors, regulate the expression of targeted genes, especially those involved in development. In filamentous fungi, homeobox genes are required for normal conidiogenesis and fruiting body formation. In the present study, we identified eight homeobox (hbx) genes in the aflatoxin-producing ascomycete, Aspergillus flavus, and determined their respective role in growth, conidiation and sclerotial production. Disruption of seven of the eight genes had little to no effect on fungal growth and development. However, disruption of the homeobox gene AFLA_069100, designated as hbx1, in two morphologically different A. flavus strains, CA14 and AF70, resulted in …

Multiple Scattering Theory For Polycrystalline Materials With Strong Grain Anisotropy: Theoretical Fundamentals And Applications, Huijing He

Department of Mechanical and Materials Engineering: Faculty Publications

This work is a natural extension of the author’s previous work: “Multiple scattering theory for heterogeneous elastic continua with strong property fluctuation: theoretical fundamentals and applications” (arXiv:1706.09137 [physics.geo-ph]), which established the foundation for developing multiple scattering model for heterogeneous elastic continua with either weak or strong fluctuations in mass density and elastic stiffness. Polycrystalline material is another type of heterogeneous materials that widely exists in nature and extensively used in industry. In this work, the corresponding multiple scattering theory for polycrystalline materials with randomly oriented anisotropic crystallites is developed. To validate the theory, the theoretical results for a series of …

Floating-Gate Transistor Photodetector, Jinsong Huang, Yongbo Yuan

Department of Mechanical and Materials Engineering: Faculty Publications

A field effect transistor photodetector that can operate in room temperature includes a source electrode , a drain electrode , a channel to allow an electric current to flow between the drain and source electrodes , and a gate electrode to receive a bias voltage for controlling the current in the channel . The photodetector includes a light - absorbing mate rial that absorbs light and traps electric charges . The light absorbing material is configured to generate one or more charges upon absorbing light having a wavelength within a specified range and to hold the one or more charges …

Note On The Rate And Energy Efficiency Limits For Additive Manufacturing, Timothy Gutowski, Sheng Jiang, Daniel Cooper, Gero Corman, Michael Hausmann, Jan-Anders Manson, Timo Schudeleit, Konrad Wegener, Matias Sabelle, Jorge Ramos-Grez, Dusan P. Sekulic

Mechanical Engineering Faculty Publications

We review the process rates and energy intensities of various additive processing technologies and focus on recent progress in improving these metrics for laser powder bed fusion processing of metals, and filament and pellet extrusion processing of polymers and composites. Over the last decade, observed progress in raw build rates has been quite substantial, with laser metal processes improving by about 1 order of magnitude, and polymer extrusion processes by more than 2 orders of magnitude. We develop simple heat transfer models that explain these improvements, point to other possible strategies for improvement, and highlight rate limits. We observe a …

Incorporating Student Reflection Into Engineering Courses, Nancy Barr

TechTalks

Critical reflection as students move through their disciplinary curriculum is one way to cultivate capacity for critical thinking. By embedding opportunities for critical reflection in disciplinary courses, educators can combine aspects of writing theory, metacognitive learning, and critical pedagogy to help students begin to frame how they will apply their skills and talents to problems effecting diverse populations. The new undergraduate ME curriculum combines applied learning and project-based learning methods in a series of four ME Practice courses. Technical communication instruction is also embedded in these courses, and the “capstone” of each course is a reflective essay. By responding to …

Space Mining Is Almost Here!, Paul Van Susant

TechTalks

When going to the Moon and Mars for extended stays with humans it is required to minimize mass by "living off the land" as soon as possible. Mining local resources and using them to produce consumables and construct simple structures can leverage launch mass to the surface of those bodies. In addition, asteroid mining will be able to provide rocket fuel to further spur economic development in CIS-Lunar space and further open up solar system activities. I am working on mining on Mars and the Moon as well as construction using local rocks.