Mechanical Engineering Commons^™

Exploring A Platinum Nanocatalytic Microcombustion-Thermoelectric Coupled Device, Dylan Moore Mcnally

Theses and Dissertations

This work aimed to create a first-generation power device for eventual application to portable electronics. A platinum nanoparticle catalytic substrate was employed in a microcombustion-thermoelectric coupled (MTC) device for the purpose of chemical-to-electrical energy conversion. Multiple microcombustion reactors were designed, fabricated, and investigated. Most importantly, the reactor configuration was designed to accommodate thermoelectric generators (TEGs) for power production. Temperature studies with catalytic combustion of methanol-air fuel mixtures were used to evaluate the thermal power generation performance of each reactor. The final reactor design enabled ignition at room temperature with the ability to achieve repeat catalytic cycles upon subsequent exposure to …

Intelligent Therapeutic Robot: Design, Development, And Control, Asif Al Zubayer Swapnil

Theses and Dissertations

This research contributes to developing an Intelligent Therapeutic Robot (iTbot) designed to provide therapy to patients with upper limb impairment due to stroke, injury, and other trauma. This robot aims to implement robotic rehabilitation based on principles of motor rehabilitation and Neuroplasticity. The iTbot, as developed in this research, can provide end-effector type rehabilitation exercises in various configurations, including motion in the vertical and horizontal plane. It can provide passive, active, and active-assisted rehabilitation therapies to patients with limited upper limb mobility.

The iTbot has been designed with simplicity in mind with a minimum viability approach. With a minimum amount …

The Implementation And Comparison Of Fuzzy Logic Control Systems To Modern Control Methods On Low-Cost Hardware, Cristian A. Barron

Theses and Dissertations

Modern control engineering provides many options to automate systems for which a mathematical model is required. Another control does not rely on the mathematical model of the system and is known as fuzzy logic control. In this study, a literature review is conducted on existing control systems strategies such as proportional integral and derivative (PID), linear quadratic regulator (LQR), and fuzzy logic controller (FLC), the complexity of the systems they control, and their strengths and weaknesses. In addition, a series of experiments are conducted, both through simulations in MATLAB Simulink and using their implementation using the actual physical hardware to …

Optimizing A Railroad Bearing Condition-Monitoring Algorithm For Use With An Onboard Wireless Low-Power Sensor Module, Jonas Regan Leano Cuanang

Theses and Dissertations

An algorithm that utilizes vibration measurements was developed by the UTRGV Center for Railway Safety to monitor the condition of railroad bearings. This algorithm uses the data collected from accelerometers on the bearing adapters to determine if there is a defect, where the defect is within the bearing, and the approximate size of the defect. Laboratory testing was performed on the UTCRS single bearing test rig. A four-second sample window of the recorded vibration data is used by the algorithm to reliably identify the defective component inside the bearing with up to a 100% confidence level. However, considerable computational power …

The Optimization Of Efficiency And Infrastructure For Modern Potable Water Treatment Plants, Brent A. Dekock

Theses and Dissertations

The USDOE Industrial Assessment Centers (IACs) is a program that is designed to help small and medium-sized manufacturing facilities reduce their overall costs and improve energy efficiency. This includes improving potable water treatment plants which supply water throughout the country. This thesis covers the process of how IAC branches and water treatment facilities generally operate, as well as several assessment recommendations that have been developed by a branch of the IAC for several water treatment plants based in the Rio Grande Valley of Texas. The steps of the assessment and water treatment process are described, and several cost saving measures …

Effect Of Adding Palm Fiber To Thermal Conductivity Of Quick Set Concrete, Monica Garcia

Theses and Dissertations

As climate change becomes a more dire issue and more readily accepted by those in power, the demand for local and systemic solutions grows louder. In urban environments, one issue of concern is the contribution of anthropogenic heat from buildings which contributes to localized warming of the environment. A method that can reduce anthropogenic heat is decreasing the thermal conductivity of building materials. The objective of this study is to examine the possibility of using palm fibers to reduce the thermal conductivity of quick-set concrete samples. The data gathered in this study are used to determine the thermal conductivity value …

The Design, Fabrication, And Testing Of A Cooling Garment, Richard James Garza

Theses and Dissertations

The aim of this research is to design a device or technology capable of cooling the user – such as a college student walking to class, for example – in a manner as convenient as putting on a jacket. The idea is to use the peltier effect – a phenomenon in which two dissimilar semi-conductors heat up and cool down with the application of an electric current – as the source of heat absorption used to cool the user. In this research it will be determined whether or not it is feasible to use such a phenomenon to keep the …

Assessing The Performance Of Reconditioned Railroad Tapered-Roller Bearings Used In Freight Rail Service, Veronica Valeria Hernandez

Theses and Dissertations

The rail industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). Bearings that are removed from service are sent to specialized facilities where they undergo a reconditioning process before the bearings can be returned to rail service. The reconditioning process has been used for decades although there has been no previous study on the effectiveness of the reconditioning process on defective bearings that were removed from service. This persuaded the researchers from the University Transportation Center for Railway Safety (UTRCS) …

Optimizing Energy Power Consumption Of Freight Railroad Bearings Using Experimental Data, Carlos Eliasar Lopez Iii

Theses and Dissertations

Throughout the railway industry, trains use systems that record total energy efficiency of a train but not energy efficiency or consumption by components. Monitoring freight bearing power consumption can support the railroad industry efforts to maintain the railroad economic competitiveness and minimize the environmental impact.

For more than a decade now, the University Transportation Center for Railway Safety (UTCRS) at the University of Texas Rio Grande Valley (UTRGV) has been collecting power consumption data for railroad bearings under various loads, speeds, ambient temperatures, bearing condition, and bearing classes. Specifically, data such as temperatures, voltages, speed, and load were collected to …

Electromagnetic Interference Shielding Effectiveness Of Interlayered Systems Containing Metal-Oxide, Conducting Polymer And Carbon Nanotube Reinforced Polymeric Composites, Shaik Merkatur Hakim Marjuban

Theses and Dissertations

The Electromagnetic Interference (EMI) Shielding Effectiveness (SE) has become one of the important requirements for the devices associated with telecommunication systems consisting of large frequency bands. The degradation of the quality of transmitting signal influenced by frequencies emitting from external sources can be reduced by covering the circuits of the devices by EMI Shielding materials like polymer composites, metal-based nanofiber mats, the metal of oxide films, etc. The investigation strives for the attenuation of EMI by introducing two composite mats from conducting polymer-based, multiwalled carbon nanotubes (MWCNTs) coated Nylon 6 nanofiber composites. Two other composite mats are also developed by …

Water-Soluble Polymers With Ceramic/Metal Nanoparticles For Use As Anode Materials In Lithium-Ion And Sodium-Ion Batteries, Roberto Orrostieta Chavez

Theses and Dissertations

Aqueous solutions of poly(vinylpyrrolidone) (PVP) with 20, 25, and 28 wt.% concentrations were successfully spun into fibers by centrifugal spinning. The pristine PVP fibers were annealed and carbonized to produce flexible carbon fibers for use as binder-free anodes in lithium-ion and sodium-ion batteries. These flexible carbon fibers were prepared by developing a novel three-step heat treatment to reduce the residual stresses in the pristine PVP precursor fibers and to prevent fiber degradation during carbonization. The average diameters of the pristine, annealed, and carbonized fibers were obtained using scanning electron microscopy (SEM), which showed that the average diameter of the carbon …

Mono And Multi-Objective Optimization And Modeling Of Machining Performance In Face Milling Of Ti6al4v Alloy, Al Mazedur Rahman

Theses and Dissertations

Titanium alloys are extensively used in numerous industries like aerospace, automotive, military, etc., due to their exclusive characteristics. But machining these alloys has always been challenging for manufacturers. This research investigates the effect of radial depth of cut on cutting forces, tool life, surface roughness (Ra), and material removal rate (MRR) during face milling of Ti6Al4V alloy. It also aims to perform mono and multi-objective optimization of response characteristics to determine the optimal input parameters, namely cutting speed, feed rate, and radial depth of cut. Taguchi method and analysis of variance (ANOVA) have been used for mono-objective optimization, whereas Taguchi-based …

The Instability Of Verge-Foliot Clocks In Contrast With The Isochronicity Of Pendulum Clocks: A Study Of Verge-Foliot Kinematics, Aaron Seth Blumenthal

Theses and Dissertations

The tower clocks of Europe starting in the 13th century CE employed a verge-foliot mechanism, which was low in both precision and accuracy due to the sensitivity of frictional losses in the system. The pendulum and Huygens’ introduction of the Theory of Involutes is shown to be a mechanism with a linear relationship to frictional losses in the system, instead of the non-linear relationship between frictional losses in verge-foliot mechanisms. The isochrone nature of vibrations of the pendulum are discussed in contrast to the variance in oscillation seen in verge-foliots. The introduction of the pendulum resulted in an improvement of …

A Modified Peng-Robinson Cubic Equation Of State Based On Bayesian Framework, Wei Chen

Theses and Dissertations

Peng-Robinson cubic equations of state (PR-EoSs) as one of the most popular two-parameter cubic equations of state (2P-EoSs) are widely used to calculate thermodynamic properties of pure substances and their mixtures. However, the prediction accuracy of 2P-EoSs varies significantly among different substances due to its intrinsic limitation. To this end, many modifications have focused on changing the dependence structure of 𝛼 function with temperature for PR-EoS to enhance prediction accuracy. In this paper, we propose a Bayesian framework to calibrate a new 𝛼 function, which is a bias-corrected parametrized model form for the PR-EoS. The developed PR-EoS with the calibrated …

Development Of Nirs Based Noninvasive Cerebrovascular Regulation Assessment, Stephanie Marie Miller

Theses and Dissertations

Alterations to cerebral blood flow (CBF) have been implicated in diverse neurological conditions, including mild traumatic brain injury, microgravity induced intracranial pressure (ICP) and intraocular pressure (IOP) increases, and mild cognitive impairment. Near infrared spectroscopy (NIRS)-measured regional cerebral tissue oxygen saturation (rSO2) provides an estimate of oxygenation of the interrogated cerebral volume that is useful in identifying trends and changes in oxygen supply to cerebral tissue and has been used to monitor cerebrovascular function during surgery and ventilation. In this study, CO2-inhalation-based hypercapnic breathing challenges were used as a tool to simulate CBF dysregulation, and NIRS was used to monitor …

Optimal Onboard Renewable Energy Charging Method To Improve Micro-Autonomous Underwater Vehicle Deployment Life, Brooklynn Dawn Byford

Theses and Dissertations

This study is an investigation of various methods for recharging a micro autonomous underwater vehicle (μAUV) onboard using renewable energy sources while deployed at sea. The goal of this project is to determine the optimal onboard renewable energy design method to be used to prolong the deployment life of a μAUV. This project specifically targeted vehicles specifications and designs similar to the Riptide Autonomous Solutions’ μAUV[1], which was used for this study. Concluding results are based on the following factors: power generation versus time, structural integrity, and design complexity. The three design method categories investigated are as follows: solar energy, …

Finite Element Method For Assessment Of Air Cushion Skirt Performance, Thomas Arthur Lipscomb

Theses and Dissertations

The objective of this thesis is to create a method of simulating the performance of new materials for use in air cushion vehicle skirts. These systems currently exhibit unacceptable design lifetimes to be considered for widespread adoption, except in specific applications such a military or rapid transport, where high cost is not an obstacle. This project also focuses on using a new high strain to failure resin system that has recently been developed, in combination with high performance reinforcing fibers, to increase the lifespan of the skirt systems. Using industry-standard finite element modelling (FEM) software, a 3d model of the …

A Finite State Automata-Based Description Of Device States For Function Modeling Of Multi-State Technical Devices, Ahmed Mohammed Sobhan Chowdhury

Theses and Dissertations

Many modern and innovative design problems require multi-modal, reconfigurable solutions. Function modeling (FM) is a common tool used to explore solutions in early stages of mechanical engineering design. Currently, function structure representations do not abet the modeling of formally-defined reconfigurable function models as graph-based function models used in early-stage systems design usually represent only one operational mode of the system. Currently there is a need, but no rigorous formalism to model multiple possible modes in the model and logically predict the behavior of the system as it transitions between the modes. Additionally, function modeling representations will benefit from dynamically capturing …

Extreme Response Analysis Of A Site-Specific Offshore Wind Turbine And Offshore Wind Farm Layout Optimization, Xiaosen Xu

Theses and Dissertations

Offshore floating wind turbines have been developed in deep water where bottom-fixed offshore wind turbines are cost-prohibitive. Gulf of Maine has one of the greatest potential wind energy on the east coast. A detailed analysis of metocean data is essential for the dynamic simulation of the floating offshore wind turbine and the offshore wind farm layout optimization. Wave scatter diagram represents the joint probability of significant wave height and peak periods. In the wind energy industry, turbulence intensity is defined as the standard deviation of the horizontal wind speed divided by the average wind speed over certain time period. Uniform …

Numerical And Experimental Investigation Of Aeration Self Mixing By Using Pulsating And Continuous Air Flow, Ahmed Ali Alkhafaji

Theses and Dissertations

Wastewater treatment is considered one of the most common forms of pollution control in the united states. Considered as an integral part of the wastewater treatment, the aeration process is the most energy-consuming process among all the processes that take place in any wastewater treatment plant. According to the United States Environmental Protection Agency (EPA), a wastewater treatment plant is expected to remove at least 85% of the suspended solids and dissolved organic compounds from the wastewater before discharging it to a river or a lake. The normal operation of the aeration process is by compressing air continuously to basin …

Design And Development Of A 7 Dof Robot With Ergonomic Shoulder For Upper Limb Rehabilitation, Md Rasedul Islam

Theses and Dissertations

With the increase of stroke patients, the number of upper limb dysfunction is increasing day by day. Robotic intervention in upper limb (UL) rehabilitation of post-stroke patients has gained much traction in recent years. Though many research groups have developed exoskeletons, existing exoskeletons have limitations in both hardware design and control approaches. In most cases, rehabilitative robotic devices have not considered the movement of the shoulder joint’s center (center of glenohumeral joint); however, this movement leads to misalignment between human joints and robot joints, which is undesirable in any circumstances. To ensure better human-robot interaction (HRI), allowing mobility of shoulder …

Designing And Investigating A Novel Biodegradable-Nontoxic Mg-Mn-Zn-Na-K Alloying System, Murtatha Mohammed Jamel

Theses and Dissertations

Magnesium has been studied extensively due to the promising potential of using magnesium alloys in different applications, especially for biomedical implantation devices and other medical applications. This growing interest is due to the abundance of magnesium metal in the Earth's crust, as well as the fact that magnesium is 37% less dense than aluminum, has good mechanical properties, and is a nontoxic element with good biocompatibility. However, most Mg-based alloys contain alloying elements that are added to improve the mechanical properties but have toxic characteristics. At the same time a number of these alloys are still used in medical applications. …

Scaling And Entropic Approaches To Clusters In Materials Science And In Network, Prosun Roy

Theses and Dissertations

The thesis we have studied, is about scaling and entropic content in various networks related to the material science, colloids and biological systems. The thesis is based on two papers:⦁ Nosonovsky M.; Roy P. Allometric scaling law and ergodicity breaking in the vascular system. Microfluidics and Nanofluidic-Springer. 2020 [Chapter 2 and 3] ⦁ Nosonovsky M.; Roy P. Scaling and Entropy in colloidal and neural networks. Entropy-MPDI. 2020 [Chapter 5 to 7] In chapter 2, we investigate scaling properties of vascular networks with fractal topology. Computational fluid dynamic (CFD) simulation of blood flow through one bifurcating vessel has been illustrated to …

An Empirical Investigation Of The Dimensions Of Product Similarity Used In Design By Analogy Of Electromechanical Products, Arnold Nkoane Tsoka

Theses and Dissertations

Analogical reasoning is known to be a core cognitive mechanism behind creative human tasks including the creativity in engineering design. Research shows that during product ideation, designers use analogy to transfer information from prior designs stored in their memory (the source of the analogy) to the task in hand (target of analogy). However, similar to any search process, the source product must be first identified as a potential candidate for analogy before this information transfer can take place. Two products can be similar along multiple dimensions such as their form, function, etc. The dimensions of similarity between two products that …

Steady-State And Transient Study Of Flow Boiling In Microchannels With Microgrooves/Micronozzles, Congcong Ren

Theses and Dissertations

Microchannel flow boiling is one of the most desired cooling solutions for high power electronics. Owing to the high latent heat of vaporization, high heat fluxes can be achieved through phase-change heat transfer. However, the enhancements of (critical heat flux) CHF and heat transfer coefficient (HTC) are usually inhibited by the transitional flow patterns, which highly influence the liquid rewetting. In the past two decades, many techniques have been explored to enhance the liquid rewetting in microscale.

In this dissertation, four parallel micro-grooves fabricated on the bottom of five microchannels (W=200 μm, H=250 μm, L=10 mm) were designed to promote …

Local Eigenvalue Modification Procedure For Real-Time Model Updating Of Structures Experiencing High-Rate Dynamic Events, Claire Rae Drnek

Theses and Dissertations

Estimating the state of structures that experience high-rate dynamics requires real-time model updating capabilities. In this work, high-rate dynamic events are characterized by 1) large uncertainties in the external loads, 2) high levels of non-stationarities and heavy disturbances, and 3) unmodeled dynamics generated from changes in system configurations. To achieve real-time model updating, an algorithm must circumvent any pre-calculations and be able to update the structure’s state on the timescale of 2 ms or less. This can be accomplished in one of two ways: either by creating a simplified model of a complex structure or by simplifying the calculations needed …

Artificial Intelligence Approaches For Structural Health Monitoring Of Aerospace Structures, Kimberly A. Cardillo

Theses and Dissertations

Structural health monitoring (SHM) and non-destructive evaluation (NDE) have been a significant research topic to help with damage detection in aerospace structures. SHM and NDE techniques are based on extracting damage sensitive features to determine the criticality of damage and lifetime of a structure. Acoustic emission (AE) signal detection is an important technique in SHM and NDE especially for fatigue crack growth. AE signals for thin aerospace structures consist of ultrasonic guided Lamb waves that propagate through the structure. This thesis focuses on AE signal repeatability, load at which AE signals occur, feature extraction, artificial intelligence and electro-mechanical impedance of …

Lamb Wave Nondestructive Evaluation And Imaging On Plate-Like Structures, Zhaoyun Ma

Theses and Dissertations

Structure components are designed with a certain service life and damage may occur, or they may come with manufacture defects. Such damage and defects may lead to structural failure if not detected in time. To ensure the structural safety and prevent catastrophic failure, effective inspection is critical for in-time maintenance. Nondestructive evaluation (NDE) and structural health monitoring (SHM) have been widely applied for damage inspection and evaluation in various industries due to their noninvasive nature. Lamb wave based NDE/SHM has become the most popular ultrasonic methods that has been proved effective in different engineering applications that can be used to …

Autonomous Drone-Based Sensor Package Deployment To The Underside Of Structures, Sabrina Rose Carroll

Theses and Dissertations

The objective of this project is to design, develop and experimentally test an Unmanned Aircraft System (UAS, commonly known as a drone) for the deployment of sensor packages to the underside of structures. This work begins with an in-depth review of existing automation techniques for various drone applications focusing on applications requiring interaction with the environment. Further reviewed is the impact of structures above the UAS during flight on the behavior of the aircraft.

Considering these topics, the development of a custom drone is presented to address the difficulties of delivering a package to the underside of a structure. Starting …

Development Of A Cfd Model For The Drying Of Aluminum-Clad Spent Nuclear Fuel, Nathaniel Cooper

Theses and Dissertations

The United States Department of Energy (DOE) currently manages approxi- mately 2500 metric tons of heavy metal (MTHM) of spent nuclear fuel (SNF), pri- marily from naval sources and domestic research reactors, and has agreements in place to accept 10,000 MTHM of aluminum-clad SNF from foreign reactors by 2029. However, due to the closure and the Yucca Mountain site and difficulties in the vitrification process, the majority of this fuel is expected to be placed in intermediate dry storage.

Before being placed in interim storage, all assemblies must be subjected to a drying process, either by forced gas recirculation (FGR) …