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Graduate Theses and Dissertations

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Full-Text Articles in Mechanical Engineering

Investigation Of Navigation Systems For Size, Cost, And Mass Constrained Satellites, Omar Awad Apr 2020

Investigation Of Navigation Systems For Size, Cost, And Mass Constrained Satellites, Omar Awad

Graduate Theses and Dissertations

The feasibility of using radically inexpensive micro-electromechanical system (MEMS) technology for navigation of a nanosatellite is investigated with a focus on attitude estimation. Typically, larger satellites are equipped with star cameras, sun sensors, or Earth horizon sensors for attitude estimation. These sensors can provide very accurate attitude measurements. A nanosatellite is highly size, power, and cost constrained and cannot readily accommodate these sensors. Our mission is to design, build, and operate a radically inexpensive nanosatellite system. While there is no consensus on what constitutes a "radically inexpensive" satellite, our goal is a maximum cost of $10,000 per unit. This ...


Laser Micropatterning Effects On Corrosion Resistance Of Pure Magnesium Surfaces, Yahya Efe Yayoglu Apr 2020

Laser Micropatterning Effects On Corrosion Resistance Of Pure Magnesium Surfaces, Yahya Efe Yayoglu

Graduate Theses and Dissertations

Magnesium and its alloys are good candidates to manufacture medical implants. They have excellent biocompatibility and because they biodegrade secondary surgical operation to remove the implant could be eliminated. However, in aqueous environments, magnesium alloys rapidly corrode, resulting in premature degradation of the implant along with biologically intolerable hydrogen gas generation. In literature, there are multiple studies focused on creating water repelling hydrophobic magnesium surfaces in order to decrease corrosion rates. Hydrophobic properties can be achieved by creation of a roughness profile on an initially smooth surface combined with a treatment that reduces the free surface energy. In theory, hydrophobic ...


Manipulation And Patterning Of Mammalian Cells Using Vibrations And Acoustic Forces, Joel Cooper Apr 2020

Manipulation And Patterning Of Mammalian Cells Using Vibrations And Acoustic Forces, Joel Cooper

Graduate Theses and Dissertations

Recently, there has been a surge in researchers and scientists investigating different methods which move, manipulate, and pattern biological cells. Multiple different mechanisms can be used for cellular manipulation, microfluidics, biochemical queues, and even optics, just to name a few. However, all techniques have their downsides. A majority of these methods require expensive equipment or reagents and can only manipulate a small number of cells at a time.

Some of the most common cell manipulation devices utilize acoustic pressure waves to move the cells to desired locations. Currently, it is unknown what level of force from these types of devices ...


Shallow Water Seafloor Geodesy: Gps On An Anchored Spar Buoy, Surui Xie Feb 2020

Shallow Water Seafloor Geodesy: Gps On An Anchored Spar Buoy, Surui Xie

Graduate Theses and Dissertations

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near-shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in marine shelves and submerged volcanoes, and certain fresh water applications, such as volcano deformation in caldera-hosted lakes. I participated in a project to develop a seafloor geodetic system for this environment based on an anchored spar buoy topped by high precision GPS. Orientation of the buoy is measured using a digital compass that provides heading, pitch, and roll information. The combined orientation and ...


Modeling Of Buildings With Electrochromic Windows And Thermochromic Roofs, Hua-Ting Kao Oct 2019

Modeling Of Buildings With Electrochromic Windows And Thermochromic Roofs, Hua-Ting Kao

Graduate Theses and Dissertations

Air conditioning and heating have increased substantially during the past two decades. According to a survey, buildings consume about 73% of the total electricity in the United States, accounting for 41% of all other energy in the world. At the same time, building skin technologies are constantly improving. Electrochromic and thermochromic are two exciting new technologies that can help reduce the energy consumption of a building. The purpose of this work is to increase our understanding of how much the use of electrochromic (EC) and thermochromic (TC) technologies can reduce the energy consumption of residential and commercial buildings in two ...


Experimental Results Of A Model Reference Adaptive Control Approach On An Interconnected Uncertain Dynamical System, Kemberly Cespedes Oct 2019

Experimental Results Of A Model Reference Adaptive Control Approach On An Interconnected Uncertain Dynamical System, Kemberly Cespedes

Graduate Theses and Dissertations

The objective of this thesis is to show the experimental validation of recently proposed adaptive control architecture for uncertain dynamical systems. The experimental validation is conducted on a benchmark mechanical system setup composed of two carts, one actuated and one unactuated, physically interconnected through a spring.

Specifically, an approach has been recently proposed to stabilize an overall interconnected system in the presence of unknown physical interconnections as well as system uncertainties in the context of model reference adaptive control. This uncertain dynamical system consists of actuated and unactuated portions physically interconnected to each other. In addition, the previous work enforces ...


Design Of Variable Wall Thickness Geometry And Performance Mapping Of Scroll Expanders For Distributed Power Generation, Arun Kumar Narasimhan Jul 2019

Design Of Variable Wall Thickness Geometry And Performance Mapping Of Scroll Expanders For Distributed Power Generation, Arun Kumar Narasimhan

Graduate Theses and Dissertations

Low-temperature heat sources such as industrial waste heat, solar, and geothermal are more suitable for small-scale power generation rather than utility scale. In order to maximize the electricity generated from low-temperature heat sources, an efficient expansion device for small-scale power output is necessary. This research work has focused on evaluating the use of a scroll expander and improving its geometrical design for the power output range of 1-25 kWe.

The first part of the work focusses on modeling the performance of a scroll expander using two non-dimensionless parameters, namely, specific speed and specific diameter. Performance of a scroll expander ...


On Distributed Control Of Multiagent Systems Under Adverse Conditions, Emre Yildirim Jun 2019

On Distributed Control Of Multiagent Systems Under Adverse Conditions, Emre Yildirim

Graduate Theses and Dissertations

The objective of this thesis is (1) to show the experimental validation of recently proposed distributed adaptive control architecture for a class of heterogeneous uncertain multiagent systems as well as (2) to theoretically propose a proportional integral controller for multiagent systems having limited resources in the presence of a disturbance with stability analyses.

With regard to (1), the distributed adaptive control architecture used in the experiment utilizes a control input having a nominal part and an adaptive augmentation part for each agent to suppress the effect of uncertainties and disturbances effectively. This architecture is capable to provide uniform ultimate boundedness ...


Design And Testing Of Experimental Langmuir Turbulence Facilities, Zongze Li Jun 2019

Design And Testing Of Experimental Langmuir Turbulence Facilities, Zongze Li

Graduate Theses and Dissertations

Langmuir Circulation is a common phenomenon driven by wind in oceans and lakes and was first studied by Langmuir in 1927. According to various ocean observations, this kind of phenomenon plays an important role in many phenomena such as the aggregation of bubbles, the distribution of plankton as well as the mixing of spilled oil and sediment in the ocean. To study this, an experimental facility has been developed in the lab which creates a small scale version of Langmuir Circulation.

This thesis is about the design and testing of this tank and surrounding aluminum frame, as well as the ...


Quantifying The Friedreich Ataxia Rating Scale And The Functional Performance Measures, Chelsea Rene Davis Jun 2019

Quantifying The Friedreich Ataxia Rating Scale And The Functional Performance Measures, Chelsea Rene Davis

Graduate Theses and Dissertations

Friedreich Ataxia (FA) is a debilitating autosomal-recessive neurodegenerative disorder which is characterized by ataxia of all four limbs, difficulty walking, areflexia, and dysarthria. Further complications of FA include diabetes, scoliosis, and hypertrophic cardiomyopathy. Approximately three-quarters of people with FA have onset before the age of 25 and in most instances, affected individuals will require the use of a wheelchair within ten years after symptoms emerge.

The current advancements in clinical trials have escalated the developmental demand for a scale which validates adjustments in FA. The Friedreich Ataxia Rating Scale (FARS) is a disease-specific semi-qualitative assessment which includes three subscales (functional ...


Synthesis And Characterization Of Molybdenum Disulfide/Conducting Polymer Nanocomposite Materials For Supercapacitor Applications, Turki S. Alamro Apr 2019

Synthesis And Characterization Of Molybdenum Disulfide/Conducting Polymer Nanocomposite Materials For Supercapacitor Applications, Turki S. Alamro

Graduate Theses and Dissertations

The needs for energy storage devices have kindled researchers desire to explore and synthesize nanocomposite materials. Storing energy efficiently, effectively and sustainably are the science and engineering communities’ highest priorities to develop electrochemical energy storage devices. Supercapacitors have become power solution not only because supercapacitors can bridge the gap between the traditional capacitors and rechargeable batteries but also because of many other advantages which include extraordinary electrochemical properties, wide working-temperature range, cost effective, safe operation and long/stable cycle life. They have higher current pules than batteries due to the mechanism of charging and discharging. Batteries charging and discharging via ...


Design Of Shape-Morphing Structures Consisting Of Bistable Compliant Mechanisms, Rami Alfattani Mar 2019

Design Of Shape-Morphing Structures Consisting Of Bistable Compliant Mechanisms, Rami Alfattani

Graduate Theses and Dissertations

This dissertation presents a design concept for shape-morphing structures that have two stable configurations. The design concept defines the methodology of transforming a planar structural shape into spatial structural shape using bistable compliant mechanisms. Bistable complaint mechanisms are used to achieve structural stable configurations. The dissertation incorporating geometrical relationships for the mechanisms that form the primary structure described in step-by-step process. This dissertation implements the design layouts for designer to creating shape-morphing structures including origami. The novel contribution of the work is classified in three models. The first model presents a methodology to induce bistability behavior into an origami reverse ...


Low Temperature Multi Effects Desalination-Mechanical Vapor Compression Powered By Supercritical Organic Rankine Cycle, Eydhah Almatrafi Jan 2019

Low Temperature Multi Effects Desalination-Mechanical Vapor Compression Powered By Supercritical Organic Rankine Cycle, Eydhah Almatrafi

Graduate Theses and Dissertations

Utilizing low grade heat sources such as geothermal, solar or waste heat has received a high attention in recent years. A lot of research has discussed using Organic Rankine Cycle (ORC) as subcritical or supercritical in power generation. However, very few studies extend their research in utilizing ORC in other applications such as desalination. For reverse osmosis (RO) desalination, which is considered a membrane technology, the use of supercritical-ORC in low grade heat sources is more favorable than subcritical-ORC. Thus, studies of utilizing either subcritical-ORC or supercritical-ORC for thermal desalination that use power and heat from Rankine cycle are rare ...


Evaluating Boom Height Control Performance With Variable Boom Roll Damping In A Suspended Boom System On Self-Propelled Sprayers, Evan Mellott Jan 2019

Evaluating Boom Height Control Performance With Variable Boom Roll Damping In A Suspended Boom System On Self-Propelled Sprayers, Evan Mellott

Graduate Theses and Dissertations

In this research, a method for improving spray boom height stability was developed and tested. Self-propelled sprayers played a critical role in agriculture by applying chemicals to crops to control the presence of weeds and pests. The spraying process needed to be controlled in a manner such that the spray boom maintained the necessary target height for uniform coverage. Deviation from target height allowed outside factors such as wind to become more prevalent during chemical application which generated opportunities for spray drift to occur and potentially harm neighboring crops and environment.

On a suspended spray boom system, terrain influences on ...


Overcoming The Limitations Of Commodity Augmented Reality Head Mounted Displays For Use In Product Assembly, Jack Miller Jan 2019

Overcoming The Limitations Of Commodity Augmented Reality Head Mounted Displays For Use In Product Assembly, Jack Miller

Graduate Theses and Dissertations

Numerous studies have shown the effectiveness of utilizing Augmented Reality (AR) to deliver work instructions for complex assemblies. Traditionally, this research has been performed using hand-held displays, such as smartphones and tablets, or custom-built Head Mounted Displays (HMDs). AR HMDs have been shown to be especially effective for assembly tasks as they allow the user to remain hands-free while receiving work instructions. Furthermore, in recent years a wave of commodity AR HMDs have come to market including the Microsoft HoloLens, Magic Leap One, Meta 2, and DAQRI Smart Glasses. These devices present a unique opportunity for delivering assembly instructions due ...


Collaborative Product Review Using Virtual Reality Interface Devices Performance Studying, Mihir Radia Jan 2019

Collaborative Product Review Using Virtual Reality Interface Devices Performance Studying, Mihir Radia

Graduate Theses and Dissertations

The study presents two research questions: 1) Can stereoscopic 3-D visualization (like Virtual Reality) improve a design reviewer’s ability to detect errors when reviewing a product model over a traditional CAD system in which 3D product models are viewed on a flat 2D computer screen? 2) Can two collaborating individuals be more effective (faster time or detect more errors) during a product design review than one individual operating alone? The answer to the first question will help provide product design reviewers, managers, and software designers in product design firms decide what features to include, and whether it is worthwhile ...


Calibration Of Structured Light System Using Unidirectional Fringe Patterns, Vignesh Suresh Jan 2019

Calibration Of Structured Light System Using Unidirectional Fringe Patterns, Vignesh Suresh

Graduate Theses and Dissertations

3D shape measurement has a variety of applications in many areas, such as manufacturing, design, medicine and entertainment. There are many technologies that were successfully implemented in the past decades to measure three dimensional information of an object. The measurement techniques can be broadly classified into contact and non-contact measurement methods. One of the most widely used contact method is Coordinate Measuring Machine (CMM) which dates back to late 1950s. The method by far is one of the most accurate method as it can have sub-micrometer accuracy. But it becomes difficult to use this technique for soft objects as the ...


Design And Rapid Prototyping Of Printed Graphene Electrochemical Biosensors For Sensitive Monitoring Of Pesticide Levels For Agricultural Use, John Hondred Jan 2019

Design And Rapid Prototyping Of Printed Graphene Electrochemical Biosensors For Sensitive Monitoring Of Pesticide Levels For Agricultural Use, John Hondred

Graduate Theses and Dissertations

While the use of pesticides (herbicides and insecticides) are critically important to meet the current and future food demands (increases crop yield by up to 40%), their overuse has shown long-term detrimental impacts on the environment from polluting watersheds used for drinking water to eutrophic “dead zones”. Current pesticide soil measurement methods (chromatography) are costly, require trained technicians, and take days to analyze; thus, farmers are taking an “over-application approach” which is pollution the environment and waterways. A disposable pesticide soil sensor would provide farmers the opportunity of precisely regulating the application of pesticides in an independent and economical fashion ...


Interdisciplinary Research Into Architecture And Music: An Evaluation Of Acoustic Performance Of A Selection Of Spaces And Of Materials, Boram Kim Jan 2019

Interdisciplinary Research Into Architecture And Music: An Evaluation Of Acoustic Performance Of A Selection Of Spaces And Of Materials, Boram Kim

Graduate Theses and Dissertations

This research examines the acoustic comforts of different occupational building types and investigates the combination of building elements, especially focusing on building layout and materials that are considered significant sources of unwanted sound. A major part of the thesis relies on a series of sound pressure (decibel) measurements in three distinctive occupational types: residential, educational, and theater buildings on the Iowa State University campus, and evaluates them with the current standard of allowable sound levels. In addition, this thesis analyzes the existing spatial and material strategies of the three types. The selected materials and their acoustic qualities will be investigated ...


Study Of Combustion Performance Of Al/Ptfe B/Ptfe And B/Al/Ptfe Composites, Liyun Feng Jan 2019

Study Of Combustion Performance Of Al/Ptfe B/Ptfe And B/Al/Ptfe Composites, Liyun Feng

Graduate Theses and Dissertations

Metal particles like aluminum and boron are of great interest as additives to energetic materials due to their high gravimetric and volumetric heat of combustion. However, the ignition temperatures of metals are quite high and their burning rates which depend upon the surface area of the burning metal agglomerates are quite slow. The naturally formed oxide layer on the surface of metal particles can further inhibit their ignition and combustion by limiting fuel/oxidizer transport. The boron oxide layer on boron particles is of particular interest due to the strong diffusion barrier formed by its presence. However, the ignition temperature ...


Process Intensification Of Biomass Fast Pyrolysis Via Autothermal Operation, Joseph Patrick Polin Jan 2019

Process Intensification Of Biomass Fast Pyrolysis Via Autothermal Operation, Joseph Patrick Polin

Graduate Theses and Dissertations

Heat transfer is the bottleneck to fast pyrolysis of biomass. Although the enthalpy for pyrolysis of biomass is relatively small, operation at temperatures around 500°C constrains heat carrier selection to inert gases and granular media that can sustain only modest thermal fluxes in practical pyrolysis systems. With heat transfer controlling the rate of pyrolysis, reactor capacity only scales as the square of reactor diameter and does not benefit from economies of scale in building larger reactors. We have eliminated this heat transfer bottleneck by replacing it with partial oxidation of pyrolysis products to provide the enthalpy for pyrolysis in ...


Experiments On Fluid Displacement In Porous Media: Convection And Wettability Effects, Tejaswi Soori Jan 2019

Experiments On Fluid Displacement In Porous Media: Convection And Wettability Effects, Tejaswi Soori

Graduate Theses and Dissertations

Immiscible and miscible two-phase fluid flow in a porous media are important problems encountered in petroleum, manufacturing, pharmaceutical, and food industries. Enhanced oil recovery process used in the petroleum industry involves driving the viscous crude oil trapped in porous reservoir rocks using low-cost fluid cocktails of surfactants-chemicals-polymers that modify the surface tension and create a favorable viscosity profile, thereby increasing the production efficiency. Such flows in porous media can be studied in laboratory conditions by considering the porous media as a bundle of interconnected capillaries which can be further simplified by modeling them in a single capillary tube.\\

In the ...


Controlled Cavitation Design And Investigation Of Its Effect In Traumatic-Brain Injuries, Alex Wrede Jan 2019

Controlled Cavitation Design And Investigation Of Its Effect In Traumatic-Brain Injuries, Alex Wrede

Graduate Theses and Dissertations

Traumatic brain injuries (TBIs) are a highly complex injury that is heavily studied in modern research. An aspect of TBIs that has been almost entirely overlooked is the existence of cavitation in the brain during a high impact injury. The presence of cavitation in the brain is a recent theory and is feared to cause detrimental damages on brain tissue. The following chapters aim to investigate this phenomena by first engineering an apparats that simulates controlled cavitation for TBI applications. The apparatus that is used in this study involves acoustical techniques to cause microbubbles (MBs) to oscillate and fragment under ...


Advanced Manufacturing And Nanotechnology For Non-Noble Metal-Based Oxygen Evolution Electrocatalysts, Bowei Zhang Jan 2019

Advanced Manufacturing And Nanotechnology For Non-Noble Metal-Based Oxygen Evolution Electrocatalysts, Bowei Zhang

Graduate Theses and Dissertations

The oxygen evolution reaction (OER) plays vital roles in electrochemical energy conversion and storage applications, including water-splitting systems, fuel cells, metal-air batteries, and CO2 reduction devices, but the development of highly active and robust OER catalysts based on non-noble metals by simple methods is challenging. In this dissertation, three major strategies are proposed for developing advanced OER electrocatalysts at low cost by simple and versatile methods. In the first work, a bimetallic Ni-Fe-P nanosheet arrays were designed and fabricated as a pre-catalyst to catalyzing super high OER current densities under alkaline and neutral media. To catalyze a 10 mA/cm2 ...


Deep Learning For Monitoring Cyber-Physical Systems, Tryambak Gangopadhyay Jan 2019

Deep Learning For Monitoring Cyber-Physical Systems, Tryambak Gangopadhyay

Graduate Theses and Dissertations

Different cyber-physical systems involving sequential data require accurate frameworks for predicting the state of the system leading to effective monitoring. If the framework is explanatory, the insights provided by the explanations can improve scientific understanding of the system. Detecting the transition to an impending instability is important to initiate effective control in a combustion system. Building robust frameworks is important in this context.

As one of the early applications of characterizing instability in a combustion system using Deep Neural Networks, we train our proposed deep convolutional neural network (CNN) model on sequential image frames extracted from hi-speed flame videos by ...


Applying Computer Vision For Detection Of Diseases In Plants, Xuan Truong Tran Jan 2019

Applying Computer Vision For Detection Of Diseases In Plants, Xuan Truong Tran

Graduate Theses and Dissertations

Early detection and quantification of diseases in food plants are critical to agriculture industry and national food security. However, limitation in technology and cost has limited the success of applying Computer Vision in Plant Science. This research builds on the recent advance of Machine Learning, GPU and smartphones to tackle the problem of fast and low cost diagnosis of plant disease. In particular, we choose soybean as the subject for applying automatic disease detection. The reason is because soybean is an important crop for the state of Iowa and an important source of food for America. The plant is however ...


Physical Characterization, Calibration, And Validation Methodology For Modeling Of Grains Using Discrete Element Method (Dem), Mohammad Mousaviraad Jan 2019

Physical Characterization, Calibration, And Validation Methodology For Modeling Of Grains Using Discrete Element Method (Dem), Mohammad Mousaviraad

Graduate Theses and Dissertations

Discrete element method (DEM) as a numerical technique for modeling granular materials has been developed for predicting the dynamic behavior of bulk particulate systems. Simulation of bulk grain handling in crop harvesting machine using the DEM technique have been challenging owing to the variability of corn conditions (e.g., grain moisture content) and limitation of robust DEM calibration procedures. Although DEM has provided an invaluable qualitative understanding of the particle flow inside or in contact with equipment, quantitatively accurate DEM simulation of particle flow and particle-machine interaction for engineering design and analysis has been generally limited. The objective of this ...


Acoustofluidic Self-Assembly Of Colloidal Materials For Additive Manufacturing, Meghana Akella Jan 2019

Acoustofluidic Self-Assembly Of Colloidal Materials For Additive Manufacturing, Meghana Akella

Graduate Theses and Dissertations

Additive manufacturing techniques like 3D printing are being used extensively to produce custom-designed products in all walks of life- from household items to human organs to space shuttle parts. However, most additive manufacturing platforms use single materials or use extremely complicated processes to print multi-material products. Also, the microstructure of the materials cannot be controlled in many cases. The 3D printing sector is a USD 7 Billion market and is expected to grow at a rate of 25% per annum. At this rate of development, the use of printing multi-material components and creating programmable material structures will be crucial for ...


Data-Driven Approaches For Improving Failure Resilience Of Engineered Systems, Mohammadkazem Sadoughi Jan 2019

Data-Driven Approaches For Improving Failure Resilience Of Engineered Systems, Mohammadkazem Sadoughi

Graduate Theses and Dissertations

Since the 1980s, major industries and government agencies worldwide have faced increasing challenges in ensuring the reliability and resilience of engineered systems. The goal of this dissertation is to create novel probabilistic analysis and design methodologies that enable engineered systems to achieve and sustain near-zero breakdown performance. Specifically, this dissertation is focused on developing new methods for simulation-based design and sensor-based diagnostics and prognostics that can be used to design engineered systems for failure resilience. The research contributions are in the areas of engineering design under uncertainty and post-design fault diagnostics which focuses on applications within wind turbines (energy generation ...


Thermal Decomposition Of Chemical Warfare Agent Simulants Diisopropyl Methylphosphonate And Tributyl Phosphate, Patrick Sanderson Jan 2019

Thermal Decomposition Of Chemical Warfare Agent Simulants Diisopropyl Methylphosphonate And Tributyl Phosphate, Patrick Sanderson

Graduate Theses and Dissertations

The pyrolysis of chemical warfare agent simulants, diisopropyl methylphosphonate

(DIMP) and tributyl phosphate (TBP), were studied in a constant volume heated cell

using infrared spectroscopy (9:35 μm to 10:55 μm) over a temperature range of 50 C to

550 C. DIMP began decomposing at 130 C and was undetectable by 280 C. The ex-

pected decomposition products observed were propene, 2-propanol and methylphospho-

nic acid. One unexpected species, methanol, was observed, and isopropyl methylphospho-

nate was not observed. Tributyl phosphate began decomposing as low as 130 C and was

undetectable by 270 C. The pyrolysis of TBP had ...