Mechanical Engineering Commons^™

Structure-Property Relationships Of Magnesium Alloys, Pouya Sharifi

Electronic Thesis and Dissertation Repository

First, I would like to acknowledge Meridian Technologies Inc., for their contributions in the materials, equipment and facilities that made this work possible.

Second, this project was also partly funded By AUTO21 Network of Centers of Excellence, an automotive research and development program focusing on issues relating to the automobile in the 21^st century. AUTO21, member of the Networks of Centers of Excellence of Canada program is funded by the Natrual Science and Engineering Research Council (NSERCT), the Social Science and Humanities Research Council (SSHRC) and multiple industries.

Third, I would like to thank the invaluable inputs and guidance …

Toxicity Assessment And Analgesic Activity Investigation Of Aqueous Acetone Extracts Of Sida Acuta Burn F. And Sida Cordifolia L. (Malvaceae), Medicinal Plants Of Burkina Faso, Kiessoum Konate, Adama Hilou, Raïssa Rr Aworet-Samseny, Alain Souza, Nicolas Barro, Mamoudou H. Dicko Prof., Jacques Datté, Bertrand M’Batchi

Pr. Mamoudou H. DICKO, PhD

Background Sida acuta Burn f. and Sida cordifolia L. (Malvaceae) are traditionally used in Burkina Faso to treat several ailments, mainly pains, including abdominal infections and associated diseases. Despite the extensive use of these plants in traditional health care, literature provides little information regarding their toxicity and the pharmacology. This work was therefore designed to investigate the toxicological effects of aqueous acetone extracts of Sida acuta Burn f. and Sida cordifolia L. Furthermore, their analgesic capacity was assessed, in order to assess the efficiency of the traditional use of these two medicinal plants from Burkina Faso. Method For acute toxicity …

Thermoelectric Module-Variable Conductance Heat Pipe Assemblies For Reduced Power Temperature Control, Corey Melnick, Marc Hodes, Gennady Ziskind, Martin Cleary, Vincent Manno

Vincent P. Manno

Thermoelectric modules (TEMs) are used to precisely maintain the setpoint temperature of photonic components generating variable heat loads under varying ambient conditions. The non-component side of TEMs is mounted onto conventional heat sinks (CHSs). At any combination of setpoint temperature, heat load and ambient temperature, there is a unique thermal resistance between the non-component side of a TEM and the ambient corresponding to minimal TEM power consumption. Indeed, a zero thermal resistance heat sink minimizes power consumption when a TEM operates in refrigeration mode, but when it operates in heating mode a relatively high thermal resistance one is optimal. This …

Simulated Effects Of Measurement Noise On Contact Measurements Between Rough And Smooth Surfaces, Caprice Gray, Robert White, Vincent Manno, Chris Rogers

Vincent P. Manno

To test the accuracy of optically measuring contact, we examined the height distribution histogram of a simulated rough surface contacting a smooth surface. We qualified the technique sensitivity as a function of the inverse signal-to-noise ratio having values ranging from 0 to 0.3. An explanation of how the analysis technique can be applied to Dual Emission Laser-Induced Fluorescence (DELIF) measurements is provided.

Modeling Of Dual Emission Laser Induced Fluorescence For Slurry Thickness Measurements In Chemical Mechanical Polishing, Caprice Gray, Chris Rogers, Vincent Manno, Robert White

Vincent P. Manno

Dual emission laser induced fluorescence (DELIF) is a technique for measuring the instantaneous thin fluid film thickness in dynamic systems. Two fluorophores within the system produce laser induced emissions that are filtered and captured by two cameras. The ratio of the images from these cameras is used to cancel the effect of the laser beam profile on the image intensity. The resultant intensity ratio can be calibrated to a fluid film thickness. The utilization of a 2-dye system when applied to Chemical Mechanical Polishing (CMP) is complicated by the fluorescence of the polymeric polishing pad and the light scattering particles …

Modeling, Analysis And Simulation Of Paste Freezing In Freeze-Form Extrusion Fabrication, Mingyang Li, Robert G. Landers, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During the freeze-form extrusion fabrication process for aqueous-based pastes, the sub-zero temperature environment aids the part in maintaining its shape by freezing the water present in the paste. The paste freezes very quickly when deposited on a substrate in a freezing environment. However, as the part’s height increases, the freezing time increases as the heat conduction rate to the substrate decreases. The freezing time can exceed the time required to extrude one layer of paste due to water’s high latent heat, thus leaving the extruded paste in its semi-liquid state and causing the part to deform or even collapse. Therefore, …

Comparison Of Compression Molding And Selective Laser Sintering Processes In The Development Of Composite Bipolar Plates For Proton Exchange Membrane Fuel Cells, Ehsan Taghipour, Ming-Chuan Leu, Nannan Guo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Bipolar plates are key components of Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In order to attain these goals, we have manufactured graphite-carbon- polymer composite plates using Compression Molding (CM), which is suitable for mass production, and Selective Laser Sintering (SLS), which is suitable for making prototypes. In this paper, the electrical …

The Applications Of Additive Manufacturing Technologies In Cyber-Enabled Manufacturing Systems, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The application of networked sensors and control in various areas, such as smart grids and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing systems to handle a significantly greater magnitude of manufacturing data. Additive manufacturing techniques print or place material layer by layer to form a part, thus have a great potential to help accelerate CEM process by printing or embedding sensors and actuators in the proper locations. This paper summarizes the roles of additive manufacturing technologies to help establish a CEM environment.

Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive Manufacturing (AM) has shown considerable promise for the future but also proposes some challenges. Many AM barriers tend to be non-technical and instead are human-centric issues such as lack of education of practitioners in AM capabilities, cultural differences, vested interests, and potentially lack of imagination. It is highly desirable for all research and educational institutions to help address these issues. This paper summarizes the additive manufacturing research and education program at the Missouri University of Science and Technology (Missouri S&T) and its interactions with various constituents, including K-12 students, undergraduate and graduate students, distance students, and industry.

The Effect Of Friction Stir Welding Process Parameters On Charpy V-Notch Impact Toughness In Hsla-65, Samuel C. Sanderson

Theses and Dissertations

HSLA-65 steel (6.4 mm thick) was friction stir welded at various welding speeds and spindle speeds. Varying weld parameters provided a range of heat inputs. Impact toughness was evaluated as a function of the different weld parameters and corresponding weld heat inputs. Charpy V-Notch (CVN) tests were conducted in parent material and at both the weld nugget centerline and heat-affected zone (HAZ) locations. The upper shelf CVN impact energy of the weld nugget was above that of the base metal for all weld parameters. The upper shelf impact toughness in the HAZ was largely unaffected by changing weld parameters. The …

Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers

Materials Science and Engineering Faculty Research & Creative Works

Ultra-high-temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as their oxidation resistance, at temperatures above 2000⁰C. However, their brittleness makes them susceptible to thermal shock failure. As graded composites, components fabricated as functionally-graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were developed …

Experimental Study Of Polymer Electrolyte Membrane Fuel Cells Using A Graphite Composite Bipolar Plate Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Selective Laser Sintering (SLS) can be used to fabricate graphite composite bipolar plates with complex flow fields for Polymer Electrolyte Membrane (PEM) fuel cells. The additive manufacturing process can significantly reduce the time and cost associated with the research and development of bipolar plates as compared to other fabrication methods such as compression molding. In this study, bipolar plates with three different designs, i.e., parallel in series, interdigitated, and bio-inspired, were fabricated using the SLS process. The performance of these SLS-fabricated bipolar plates was studied experimentally within a fuel cell assembly under various operating conditions. The effect of temperature, relative …

Multi-Color Cavity Ringdown Based Detection Method And Apparatus, Scott W. Reeve, Susan Davis Allen

Mechanical Engineering - Daytona Beach

A multi-color cavity ringdown based spectrometer system is housed in a light tight enclosure to detect the presence of trace quantities of gas phase molecules emanating from a subject, explosives, drugs, or hazardous materials. A method is also disclosed for simultaneous real time detection of gas phase molecules emanating from explosives, drugs, hazardous materials, a subject's breath skin or bodily fluid.

Efficient Characterization Of Structural Dynamic Responses Under Uncertainties: From Order-Reduced Simulation To Data-Driven Emulation, Zeping Xia

Master's Theses

The efficiency of sampling remains as one of the major challenges for uncertainty analysis in structural dynamics. In the context of numerical experiments, this difficulty primarily lies in the fact that every single run of a numerical model, which usually is of large scale in modern engineering practice, would be expensive in terms of CPU times and memories. Nonetheless, understanding and predicting dynamic characteristics of structural systems with uncertainties is important for structural design, assessment and control. In order to develop fast and economical sampling techniques for characterizing structural dynamics, we explored two categories of methods from two opposite direction: …

The Extraction Of Shock Waves And Separation And Attachment Lines From Computational Fluid Dynamics Simulations Using Subjective Logic, Matthew C. Lively

Theses and Dissertations

The advancement of computational fluid dynamics to simulate highly complex fluid flow situations have allowed for simulations that require weeks of computation using expensive high performance clusters. These simulations often generate terabytes of data and hinder the design process by greatly increasing the post-processing time. This research discusses a method to extract shock waves and separation and attachment lines as the simulation is calculating and as a post-processing step. Software agents governed by subjective logic were used to make decisions about extracted features in converging and converged data sets. Two different extraction algorithms were incorporated for shock waves and separation …

Study On The Fracture Toughness Of Friction Stir Welded Api X80, Allan M. Tribe

Theses and Dissertations

High strength low alloy (HSLA) steels have been developed to simultaneously have high yield strength and high fracture toughness. However, in practical applications steel must be welded. Traditional arc welding has proven detrimental to the fracture toughness of HSLA steels. Friction stir welding has recently shown mixed results in welding HSLA steels. The range of welding parameters used in these recent studies however has been very limited. With only a few welding parameters tested, the effect of spindle speed, travel speed, and heat input on the fracture toughness of friction stir welded HSLA steel remains unknown. To understand how the …

Visor Scratch Repair And Prevention, Andrew Heafitz, Benjamin Linder, Marta Luczynska, Mark Scott

Benjamin Linder

Severe eye injuries occur in 30 percent of demining accidents. Visors are known to be effective personal protective equipment when worn properly, but deminers often lift or remove their visors because scratches, glare or fog make them hard to see through, or because they are hot, heavy and uncomfortable to wear. Addressing each of these specific design problems could increase visor use and prevent a significant number of debilitating injuries. This paper presents methods for preventing and eliminating scratches on demining visors.

Locking Centrifuge Rotor Cover Assembly, Benjamin Linder, Don Lee, Amy Battles, David Otten

Benjamin Linder

A centrifuge rotor cover assembly for use with a centrifuge having a rotor and a housing enclosing the rotor and including a lid movable between a closed position overlying the rotor and an open position providing access to the rotor. The cover assembly includes a rotor cover removably coupled to the lid. Means are provided for engaging the rotor cover with the rotor for rotation therewith and for uncoupling the cover from the lid in response to the lid being moved to the closed position. Means are also provided for disengaging the rotor cover from the rotor and for coupling …

The Design And Manufacturing Of The Solar Furnace Reactor Table, Chris Baum, Zach Saylor, Andrew Schiller

Symposium on Undergraduate Research and Creative Expression (SOURCE)

The James S. Markiewicz Solar Energy Research Facility at Valparaiso University will concentrate energy from the sun into a reactor containing unprocessed materials. The concentrated light causes a reaction to occur, turning unprocessed materials into alternative energy products. Accurate placement of the reactor at the focal point of the concentrator is necessary to allow the maximum amount of solar energy to enter the reactor. The Reactor Table was designed and built by Valparaiso University students and faculty. The table controls the placement of the reactor at the focal point of the concentrator quickly and easily by using a computer located …

Designing A Calorimeter To Calibrate An Optical Radiative Flux Measurement System To Find The Power Entering A Solar Reactor, Jesse Fosheim, Melissa Meyer, Jonathan Ogland-Hand

Symposium on Undergraduate Research and Creative Expression (SOURCE)

A solar furnace has been constructed at Valparaiso University to test the performance of various solar chemical reactors. A primary performance index of a solar chemical reactor is the efficiency, or the fraction of the energy that enters the reactor that is utilized in the chemical reaction. To calculate this efficiency, we must first know how much solar power is entering the reactor. An optical radiative flux measurement system has been developed that gives the solar flux distribution over the aperture of the reactor, but must be calibrated to provide the actual power level. Therefore, a calorimeter was designed and …

Electrical Control And Safety System For Solar Furnace, Parisa Nasserifar, Jason Toberman

Symposium on Undergraduate Research and Creative Expression (SOURCE)

The Valparaiso University College of Engineering has recently received a donor gift and a federal earmark to design and manufacture a solar furnace facility. In the solar facility, a heliostat will reflect sunlight straight into the concentrator at every instant. However, due to manufacturing tolerances and inaccuracy in sun’s position model a sun sensor is added in the heliostat sun tracking system. The sun sensor fine adjusts the heliostat’s position so the reflected sunlight is normal to the concentrator. Our goal is to develop a sun sensor that provides an unbalanced output signal when the sensors receive an unbalanced light …

Vu Solar Furnace: Final Design And Construction Of Louver System, Chris Baum, Zach Saylor, Andrew Schiller, Gretchen Vanheeren

Symposium on Undergraduate Research and Creative Expression (SOURCE)

Solar energy is an environmentally clean and abundant alternative to the use of fossil fuels. One method of harnessing solar energy, solar thermal electrochemistry, uses a solar furnace to concentrate sunlight and heat a reactor to temperatures around 2000 K. At such high temperatures, metallic oxides can be decomposed into metals and oxygen with minimal electrical work. The solar furnace used for this process consists of a heliostat, which tracks the sun; a concentrator, which focuses the light to a single point; and a reactor in which the chemical reaction takes place. To control the amount of sunlight entering the …

Computational Scheme Guided Design Of A Hybrid Mild Gasifier, You Lu

University of New Orleans Theses and Dissertations

A mild gasification method has been developed to provide an innovative clean coal technology. The objectives of this study are to (a) incorporate a fixed rate devolatilization model into the existing 2D multiphase reaction model, (b) expand the 2D model to 3D and (c) utilize the improved model to investigate the mild-gasification process and guide modification of the mild-gasifier design. The Eulerain-Eulerian method is employed to calculate both the primary phase (air) and secondary phase (coal particles). The improved 3D simulation model, incorporated with a devolatilization model, has been successfully developed and employed to determine the appropriate draft tube dimensions, …

Passive Control Architectures For Collaborative Virtual Haptic Interaction And Bilateral Teleoperation Over Unreliable Packet-Switched Digital Network, Ke Huang

Doctoral Dissertations

This PhD dissertation consists of two major parts: collaborative haptic interaction (CHI) and bilateral teleoperation over the Internet. For the CHI, we propose a novel hybrid peer-to-peer (P2P) architecture including the shared virtual environment (SVE) simulation, coupling between the haptic device and VE, and P2P synchronization control among all VE copies. This framework guarantees the interaction stability for all users with general unreliable packet-switched communication network which is the most challenging problem for CHI control framework design. This is achieved by enforcing our novel \emph{passivity condition} which fully considers time-varying non-uniform communication delays, random packet loss/swapping/duplication for each communication channel. …

Parametric Instability Investigation And Stability Based Design For Transmission Systems Containing Face-Gear Drives, Meng Peng

Doctoral Dissertations

The objective of this dissertation is to provide a novel design methodology for face-gear transmissions based on system stability - a dynamics viewpoint. The structural dynamics models of transverse and torsional vibrations are developed for face-gear drives with spur pinions to investigate the parametric instability behavior in great depth. The unique face-gear meshing kinematics and the fluctuation of mesh stiffness due to a nonunity contact-ratio are considered in these models. Since the system is periodically timevarying, Floquet theory is utilized to solve the Mathieu-Hill system equations and determine the system stability numerically. To avoid complex numerical computations, Treglod’s approximation is …

Measurement Of Power-Law Creep Parameters By Instrumented Indentation Methods, Caijun Su

Doctoral Dissertations

New experimental methods have been developed to measure the uniaxial power-law creep parameters α [alpha] and n in the relation έ[epsilon dot]=α[alpha]σⁿ[sigma] (έ [epsilon dot] is the creep strain rate and σ [sigma] is the creep stress) from the load, time, displacement and stiffness data recorded during an instrumented indentation experiment performed with a conical or pyramidal indenter. The methods are based on an analysis of Bower et al., which relates the indentation creep rate to the uniaxial creep parameters based on simple assumptions about the constitutive behavior (Bower et al., 1993 …

Nonlinear Vibration Control And Limit-Cycle Analysis Of Rotor/Autobalancer Systems Equipped With Hydrodynamic And Active Magnetic Bearing Supports, Daeyi Jung

Doctoral Dissertations

In recent years, there has been much interest in the use of automatic balancing devices (ABDs) in rotating machinery. Autobalancers consists of several freely moving eccentric balancing masses mounted on the rotor, which, at certain operating speeds, act to cancel rotor imbalance. This “automatic balancing” phenomena occurs as a result of nonlinear dynamic interactions between the balancer and rotor wherein the balancer masses naturally synchronize with the rotor with appropriate phase to cancel the imbalance. However, due to inherent nonlinearity of the autobalancer, the potential for other undesirable non-synchronous limit-cycle behavior exists. In such situations, the balancer masses do not …

Vision-Based Robot Control In The Context Of Human-Machine Interactions, Andrzej Nycz

Doctoral Dissertations

This research has explored motion control based on visual servoing – in the context of complex human-machine interactions and operations in realistic environments. Two classes of intelligent robotic systems were studied in this context: operator assistance with a high dexterity telerobotic manipulator performing remote tooling-centric tasks, and a bio-robot for X-ray imaging of lower extremity human skeletal joints during natural walking. The combination of human-machine interactions and practical application scenarios has led to the following fundamental contributions: 1) exploration and evaluation of a new concept of acquiring fluoroscope images of musculoskeletal features of interest during natural human motion, 2) creation …

Technology Portal For Energy Efficient Buildings, Larry D. Hermanson, Daniel Studer, Annie Mroz

STAR Program Research Presentations

Project: Technology Portal for Energy Efficient Buildings

Date: August 2, 2012

Author: Larry Hermanson

Mentor: Daniel Studer

Cohort: Annie Mroz

Lab site: National Renewable Energy Laboratory (NREL)

Buildings account for 71% of the electricity demand and 39% of the primary energy consumption in the United States. The Commercial Buildings Group at NREL provides builders, designers and building owners accurate information to significantly improve the energy efficiency of new and existing buildings. The Technology Portal for Energy Efficient Buildings will increase the accessibility of standardized and credible energy performance data for all building systems, thereby allowing building owners to better evaluate …

Sound Absorption Properties Of Functionally Graded Polyurethane Foams, Olivier Doutres Ph.D., Noureddine Atalla Pr.

Olivier Doutres Ph.D.

Noise control over a wide frequency band is an increasingly important design criterion in the building and transport industries. Examples of well known broadband passive concepts for optimal sound absorption are multi-layering with graded properties across the thickness and optimization of the material shape (e.g., wedges). However, for typical applications, the material thickness is limited and shaping or use of different material costly. Thus, there is growing interest for developing acoustical materials having microstructure properties gradient at the micro- or meso-scale; also known as Functionally Graded Materials (FGM). Even if sophisticated models are available to predict the acoustic behavior of …