Mechanical Engineering Commons^™

A Distance Based Multisample Test For High-Dimensional Compositional Data With Applications To The Human Microbiome, Qingyang Zhang, Thy Dao

Mathematical Sciences Faculty Publications and Presentations

Background

Compositional data refer to the data that lie on a simplex, which are common in many scientific domains such as genomics, geology and economics. As the components in a composition must sum to one, traditional tests based on unconstrained data become inappropriate, and new statistical methods are needed to analyze this special type of data.

Results

In this paper, we consider a general problem of testing for the compositional difference between K populations. Motivated by microbiome and metagenomics studies, where the data are often over-dispersed and high-dimensional, we formulate a well-posed hypothesis from a Bayesian point of view and …

Nondestructive Evaluation (Nde) Of Additively Manufactured Metal (Amm) Parts Using Ultrasonic Testing (Ut), Austin M. Thomas

Master's Theses

Additive manufacturing is a category of emerging manufacturing processes that have applications in creating metal components with high value and complexity. The adoption of these parts is limited by the lack of fully developed nondestructive techniques for identifying internal defects. The use of ultrasonic testing for detecting and measuring internal features in additively manufactured metal parts is investigated. A low-cost ultrasonic immersion testing system was designed, constructed, and validated for the inspection of an additively manufactured titanium specimen with artificial defects as well as other metal artifacts. An ultrasound calibration block was additively manufactured from stainless steel type 316L and …

The Varied Thermal Response Of Magnetic Iron-Oxide Nanoparticles During Induction Heating In Liquid And Solid-Liquid Phase Change Mediums, Joshua Tompkins

Graduate Theses and Dissertations

This study investigates the induction heating response of uncapped iron oxide nanoparticles sonically dispersed as a nanofluid and mechanically distributed in solid phase change materials. The nanoparticles examined have a mean diameter of 14.42 nm and are magnetically heated in an alternating magnetic field at an amplitude of 72.6 kA/m at frequencies of 217, 303, and 397 kHz. Nanoparticle characterization was undertaken through transition electron microscopy, x-ray diffraction, and dynamic light scattering when in suspension. Carrier fluids were characterized through viscosity, heat capacity, and density measurements which were used in the calorimetric calculation of the specific absorption rate (SAR) of …

Adhesion And Deformation Mechanisms Of Polydopamine And Polytetrafluoroethylene: A Multiscale Computational Study, Matthew Brownell

Graduate Theses and Dissertations

Polydopamine (PDA) has been shown to bond via covalent bonding, van der Waals forces, and hydrogen bonding and is known to adhere strongly to almost any material. The application of PDA between a substrate and a PTFE surface coating has resulted in low friction and a greatly reduced wear rate. Previous research probing the capabilities and limitations of PDA/PTFE films have studied the wear and mechanical properties of the film, but the overall adhesive and deformation mechanisms remain unclear.

In this research, we investigate the tribological properties of PDA and PTFE molecules and composites from the atomic to the microscale …

Design, Fabrication, And Reliability Effects Of Additively Manufactured First Level Compliant Interconnects For Microelectronics Application, Tumininu David Olatunji

Graduate Theses and Dissertations

Semiconductor packaging and development is greatly dependent on the magnitude of interconnect and on-chip stress that ultimately limits the reliability of electronic components. Thermomechanical related strains occur because of the coefficient of thermal expansion mismatch from different conjoined materials being assembled to manufacture a device. To curb the effect of thermal expansion mismatch between conjoined parts, studies have been done in integrating compliant structures between dies, solder balls, and substrates. Initial studies have enabled the design and manufacturing of these structures using a photolithography approach which involves a high number of fabrication steps depending on the complexity of the structures …

Mechanical And Frictional Behavior Of Textured And Non-Textured Surfaces, Raghuram R. Santhapuram

Graduate Theses and Dissertations

Tribology is the study of surfaces where two objects are sliding against another. Significant energy is lost due to friction between the sliding surfaces. Therefore, developing or designing surfaces to minimize friction is critical for the durability and reliability of the mechanical components. Several researchers have identified that surface texturing at the nanoscale (nanotexture) would reduce the friction between the contacting surfaces. The nanotextured surfaces have several applications in microelectromechanical systems and nanoelectromechanical systems. This dissertation employs molecular dynamics simulations to investigate the frictional and mechanical response of nanotextured aluminum (Al) and Al/amorphous silicon (a-Si) composite surfaces.

This study determines …

Numerical Simulations Of Directed Self-Assembly Methods In Di-Block Copolymer Films For Efficient Manufacturing Of Nanoscale Patterns With Long-Range Order, Joseph Hill

Graduate Theses and Dissertations

Directed self-assembly (DSA) of block copolymers (BCPs) has been shown as a viable method to achieve bulk fabrication of surface patterns with feature sizes smaller than those available through traditional photolithography. Under appropriate thermodynamic conditions, BCPs will self-assemble into ordered micro-domain morphologies, a desirable feature for many applications. One of the primary interests in this field of research is the application of thin-film BCPs to existing photolithography techniques. This “bottom-up” approach utilizes the self-assembled BCP nanostructures as a sacrificial templating layer in the lithographic process.

While self-assembly occurs spontaneously, extending orientational uniformity over centimeter-length scales remains a critical challenge. A …

Nanoscale Mechanics Of Disordered Biomolecules In Brain, Md Ishak Khan

Mechanical and Aerospace Engineering Dissertations - Archive

The long-term objective of this dissertation is to link blast-induced traumatic brain injury (TBI) with multiscale, multiphysics damage evolution in the brain using experimentally verifiable computations and simulations. The short-term goal is to conduct modeling and simulation to correlate dynamic mechanical loading to damage in sub-axonal components. It is known that the interior of the brain at the macroscale (10^-1 m) is composed of two distinct components, the grey matter, and the white matter. Within the cortex, the grey matter primarily takes the form of cortical columns (mesoscale: 10^-3 m), which are six layered structures, each composed of 8-10 thousand …

Analytical And Experimental Studies On Mixing In Supersonic Flows, Vijay Gopal

Mechanical and Aerospace Engineering Dissertations - Archive

Mixing enhancement in supersonic flow is an important domain of research for enabling the realization of efficient and scalable high speed air-breathing engines (scramjet). Introducing streamwise vorticies in supersonic flow and tailoring their interactions for mixing enhancement is the primary motivation for the present research study. Leveraging the research performed in the group at the Aerodynamics Research Center (ARC), systematic experimental studies on mixing enhancement is carried out in supersonic flows by tailoring the selected modes of streamwise vortex interactions with the aid of in-house developed reduced order method VorTX. This method utilizes the lifting line-vortex theory in supersonic flow …

Automating Aerospace Synthesis Code Generation A Tool For Generic Vehicle Design And Technology Forecasting, Thomas Peter Mccall

Mechanical and Aerospace Engineering Dissertations - Archive

The principal development and deliverable of this research is a generic synthesis assembling decision support environment for early conceptual design that automates the assembly of synthesis architectures for enhanced product exploration and technology forecasting. The objective of this research is to develop a baseline environment to assess complex vehicle automated synthesis architecture synthetization procedures for adaptation into a greater cognitive system. This tool has been developed as a precursory and developmental task in an initiative towards an artificial intelligence design and research assistant peer. The artificial intelligence peer is a perceived course for future design system evolution in the continued …

Using Numerical Modeling To Determine Viscous Losses Within Helium Turbomachinery, Benjamin Uhlig

Mechanical and Aerospace Engineering Theses - Archive

As the consumption of energy has increased relentlessly over the last few decades, the need for reliable clean energy generation has increased as well. Currently, nuclear power is the only method capable of providing a stable supply of clean energy, although the nuclear energy generation process still requires improvement. Specifically, there is a need to increase efficiencies while reducing the risks of radioactive contamination. It is possible that both these issues may be mitigated using helium as the working fluid. However, the performance of turbomachinery using helium must be evaluated before its use can be implemented. To do this, Balaji …

Determination Of Landing Zones Of Quadrotors Experiencing In-Flight Failures, Ahmet Tolcu

Mechanical and Aerospace Engineering Theses - Archive

In recent years, unmanned aerial vehicles (UAVs), commonly known as drones, have attained considerable prominence in a wide range of areas ranging from military operations, including surveillance, intelligence, and reconnaissance, to nonmilitary sectors such as delivery, entertainment, and agriculture. The low cost, small size, and ease of use of quadrotors provide significant advantages for such missions. At the same time however, the occurrence of physical failures in such vehicles, particularly if these failures occur while flying over highly populated areas, can pose considerable risk to people and premises on the ground. This thesis investigates scenarios of power loss due to …

Experimental Assessment Of Rack-Level Dynamic Direct To Chip Liquid Cooling For Data Center And It Equipment Reliability, Amith Mathew

Mechanical and Aerospace Engineering Theses - Archive

Data centers are used by organizations for storing, processing and distribution of data. These data centers are run through-out the year due to which their thermal management is a growing concern. A popular way of eliminating such thermal cooling issues is Liquid cooling. Conventionally Liquid cooling involves the supply of constant liquid flow (water or refrigerant) through the IT rack irrespective of the IT load, which in a Multi-chip module causes hotspots and temperature gradients across the module due to non-uniform heating. A dynamic cold-plate and a regulatory flow control device (FCD) is incorporated in this experimental set-up to assist …

Attitude Determination And Control Of Arksat-1, Jared Gilliam

Mechanical Engineering Undergraduate Honors Theses

ARKSAT-1 is a nanosatellite developed at the University of Arkansas as part of NASA’s CubeSat Launch Initiative (CSLI). The goal of ARKSAT-1 is to utilize an LED emitter paired with a ground-based tracking system to perform measurements of the composition of the atmosphere using spectroscopy. As part of its function, it is imperative that the satellite is able to control its orientation so that the emitter is aligned as closely as possible with the ground tracker. To do this, the attitude control system of ARKSAT-1 uses magnetic actuators to create a torque on the satellite by interacting with Earth’s magnetic …

Coin Recovery Ii, Carly Lofthouse

Undergraduate Honors Capstone Projects

Western Metals Recycling (WMR), a subsidiary of NUCOR Steel, is a metals recycling company with a location in Plymouth, Utah. At Plymouth, a 50 NT/hr. non-ferrous recovery plant uses eddy current technology to generate a non-ferrous product called zorba. Zorba is a mix of aluminum, copper, brass, zinc, printed circuit boards, coins, lead, and the like. (Figure 1) The market value of zorba varies but generally ranges from $0.30 to $0.50 per pound. The value of the coins (not including pennies) is much higher than zorba price. The team's objective is to upgrade and optimize the existing trommel equipment to …

Heat Transfer Modeling And Optimization Of A Carbonized Microvascular Solar Receiver, Taylor Brown

Boise State University Theses and Dissertations

Concentrating solar power is an emerging renewable energy source. The technology can collect and store thermal energy from the sun over long durations, generating electricity as needed at a later time. Current CSP systems are limited to a maximum operational temperature due to constraints of the working fluid, which limits the maximum possible efficiency of the system. One proposed pathway forward is to utilize a gas phase for the working fluid in the system such as supercritical carbon dioxide.

A composite gas phase modular receiver is being developed by researchers at Boise State University and the University of Tulsa. The …

Understanding The Effects Of Long-Duration Spaceflight On Fracture Risk In The Human Femur Using Finite Element Analysis, Keyanna Brielle Henderson

Master's Theses

Long-duration spaceflight has been shown to have significant, lasting effects on the bone strength of astronauts and to contribute to age-related complications later in life. The microgravity environment of space causes a decrease in daily mechanical loading, which signals a state of disuse to bone cells. This affects the bone remodeling process, which is responsible for maintaining bone mass, causing an increase in damage and a decrease in density. This leads to bone fragility and decreases overall strength, posing a risk for fracture. However, there is little information pertaining to the timeline of bone loss and subsequent fracture risk.

This …

Field Testing The Effects Of Low Reynolds Number On The Power Performance Of The Cal Poly Wind Power Research Center Small Wind Turbine, John B. Cunningham

Master's Theses

This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, C­_p, vs. tip speed ratio, λ, characteristics. A description of both the wind turbine and test setup are provided. Data filtration and processing techniques were developed to ensure a valid method to analyze and characterize wind power measurements taken in a highly variable environment. The test results demonstrated a significant drop in the …

Radio Frequency Emissions From Dark-Matter-Candidate Magnetized Quark Nuggets Interacting With Matter, J. Pace Vandevender, C. Jerald Buchenauer, Chunpei Cai, Aaron P. Vandevender, Benjamin A. Ulmen

Michigan Tech Publications, Part 1

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks. They are also called strangelets, nuclearites, AQNs, slets, Macros, and MQNs. Quark nuggets are a candidate for dark matter, which has been a mystery for decades despite constituting ~ 85% of the universe’s mass. Most previous models of quark nuggets have assumed no intrinsic magnetic field; however, Tatsumi found that quark nuggets may exist in magnetars as a ferromagnetic liquid with a magnetic field BS = 1012±1 T. We apply that result to quark nuggets, a dark-matter candidate consistent with the Standard Model, and …

A Low-Cost Secure Iot Mechanism For Monitoring And Controlling Polygeneration Microgrids, Josué Martínez-Martínez, Diego Aponte-Roa, Idalides Vergara-Laurens, Wayne Weaver

Michigan Tech Publications, Part 1

The use of Internet-connected devices at homes has increased to monitor energy consumption. Furthermore, renewable energy sources have also increased, reducing electricity bills. However, the high cost of the equipment limits the use of these technologies. This paper presents a low-cost secured-distributed Internet of Things (IoT) system to monitor and control devices connected in a polygeneration microgrid, as a combined power system for local loads with renewable sources. The proposed mechanism includes a Wireless Sensor Actuator Networked Control System that links network nodes using the IEEE 802.15.4 standard. The Internet communication enables the monitor and control of devices using a …

Material Model Characterization Of A Ti/Sic Metal Matrix Nanocomposite Coating Subjected To Hypervelocity Impact, Pouya Shojaei, Riccardo Scazzosi, Mohamed Trabia, Brendan Otoole, Marco Giglio, Xing Zhang, Yiliang Liao, Andrea Manes

Mechanical Engineering Faculty Research

Titanium alloys have been extensively used in the aerospace industry because of their outstanding properties, such as high strength-to-weight ratios, high corrosion resistances, and high melting points. However, it is hypothesized that the performance of titanium alloys can be further enhanced to be more resistant to hypervelocity impact by coating them. Earlier experimental investigations showed that coating a Ti-6Al-4V substrate by Ti/SiC Metal Matrix Nanocomposite (MMNC) improved hypervelocity impact resistance of the composite. The coating had 7% SiC by volume. These experiments were simulated using the Smoothed Particle Hydrodynamics (SPH) modeling approach. Johnson-Cook material models were used for the Ti-6Al-4V …

Lead To Can Abrasion (Ltca) Test, Scott Mangin, Karthik Padmanabhan, Craig Icban

Mechanical Engineering

Pacemakers are medical devices which regulate a person’s heartbeat through electric pulses delivered via an endocardial lead attached to the heart. When a pacemaker is implanted in a patient, there is usually excess length left on the lead. Surgeons will typically wrap the excess lead length around the pacemaker device and close the wound. However, wrapping the lead around the pacemaker outer surface can open the lead to abrasion and cause the lead’s vital electrical insulation to be compromised. This is currently tested using an existing abrasion fixture at Abbott. However, the current tester does not yield consistent data results …

A.C. Moyer Eye-Cap Manufacturing, Thais Bertolus, Alexa Steidl, Hana Welsh, Jarod Kinney, Maya Willis

Mechanical Engineering

A.C. Moyer company has been making eye caps as a family business since 1947. Eye caps are a product used during the embalming process. Currently the machines being used to produce the eye caps are outdated and unsafe. We are a team of 5 mechanical engineering students tasked with either designing new machines or updating the existing machines to make the manufacturing process more efficient, automated, and safer. This document describes the design process, provides background, relevant research, establishes project objectives, and defines plans for project implementation.

Low-Intensity Vibration Restores Nuclear Yap Levels And Acute Yap Nuclear Shuttling In Mesenchymal Stem Cells Subjected To Simulated Microgravity, Matthew Thompson, Kali Woods, Joshua Newberg, Julia Thom Oxford, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Reducing the musculoskeletal deterioration that astronauts experience in microgravity requires countermeasures that can improve the effectiveness of otherwise rigorous and time-expensive exercise regimens in space. The ability of low-intensity vibrations (LIV) to activate force-responsive signaling pathways in cells suggests LIV as a potential countermeasure to improve cell responsiveness to subsequent mechanical challenge. Mechanoresponse of mesenchymal stem cells (MSC), which maintain bone-making osteoblasts, is in part controlled by the “mechanotransducer” protein YAP (Yes-associated protein), which is shuttled into the nucleus in response to cyto-mechanical forces. Here, using YAP nuclear shuttling as a measurement outcome, we tested the effect of 72 h …

Toward Understanding Underlying Mechanisms Of Drag Reduction In Turbulent Flow Control, Alex Rogge

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

The underlying mechanisms of three different flow-control strategies on drag reduction in a turbulent channel flow are investigated by direct numerical simulations. These strategies include the addition of a small concentration of long-chain polymers into a fluid, the incorporation of slip surfaces, and the application of an external body force. While it has been believed that such methods lead to a skin-friction reduction by controlling near-wall flow structures, the underlying mechanisms at play are still not as clear. In this study, a temporal analysis is employed to elucidate underlying drag-reduction mechanisms among these methods. The analysis is based on the …

Fluid Modeling And Analysis Of A Mash Tl-6 Vehicle Model, Elisa Vasquez

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

The objective of this research project was to replicate the dynamic behavior of a truck-tank trailer combination vehicle using representative dimensions, properties, and inertias of the trailer/fluid ballast combination. A literature review was completed describing techniques for modeling fluids and fluid-container interactions using finite element analysis. Various fluid modeling techniques were identified, and parameters associated with those models were archived. Next, researchers utilized the tank geometry of the elliptical straight-frame 5949 trailer produced by LBT Inc. to generate a finite element mesh using finite element analysis preprocessors HyperMesh and LS PrePost. Material properties were taken from reference guides, research papers, …

Development Of A Tiny House Design Tool To Increase Safety, Efficiency, And Cost-Effectiveness, Michael Joseph Stratton Ii

Masters Theses

A growing number of people are choosing to live more sustainably, and this is commonly done through living in an extremely small house, also called a “tiny house”. There is no set definition for a tiny house, but it typically refers to a structure less than 500 ft2, sometimes built by the homeowner, and frequently built on a travel trailer.

The popularity of tiny houses has increased over the years due to different television shows, internet videos, and photo sharing websites, but the technical details are rarely covered, which is why this study examines the structural, stability, weight, and thermal …

Analysis Of Glass Transition Temperature Of Pcb & Substrate Using Dynamic Mechanical Analysis & Thermomechanical Analysis, Shristi Yadav

Mechanical and Aerospace Engineering Theses - Archive

Electronic Packaging materials and their properties examines the array of packaging architecture, outlining the classification of materials and their use for various tasks requiring performance over time. Glass transition temperature plays a vital role in the field of Electronic Packaging. It is the temperature range where the material changes from a rigid glassy material to a soft (not melted) material and is usually measured in terms of the stiffness or modulus. The commonly used component in today’s electronics world are PCBs and substrate which are an integral part of it. There are few known ways of finding out the Glass …

Globally Optimal Passive Compliance Control For Tasks Having Multiple Homotopy Classes, Jacob J. Rice, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

Redundant serial manipulators with variable stiffness actuators (VSAs) are capable of passive compliance control, in which the elastic behavior of the end-effector is controlled for robust interaction with a stiff environment. This paper addresses the problem of finding the globally optimal joint manipulation path (sequence of joint positions and compliances) that yields a desired task manipulation path (sequence of end-effector positions and compliances) when there is one degree of redundancy. The space of admissible joint paths can be very complex, with multiple bifurcations resulting in multiple homotopy classes of joint paths. Bifurcations due to singularities in the combined kinematic and …

Coalescence Speed Of Two Equal-Sized Nanobubbles, Eric Bird, Jun Zhou, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In This Work, We Use Molecular Dynamics (MD) Simulations Coupled with Continuum-Based Theoretical Analysis to Study the Coalescence Dynamics of Two Equal-Sized Nanobubbles (NBs). We First Derive a Governing Equation for the Evolution of the Capillary Bridge Radius between Two Coalescing NBs from the Axisymmetric Navier-Stokes Equation. to Verify the Prediction from the Governing Equation, We Carry Out MD Simulations of the Coalescence of Two NBs in a Lennard-Jones Fluid System and Directly Measure the Bridge Radius, Rb, as a Function of Time, T. by Varying the Bubble Diameter, We Change the NB Ohnesorge Number from 0.46 to 0.33. in …