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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 ...


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 ...


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 ...


A Locally-Implicit Lax-Wendroff Discontinuous Galerkin Scheme With Limiters That Guarantees Moment-Realizability For Quadrature-Based Moment Closures, Christine Wiersma Jan 2019

A Locally-Implicit Lax-Wendroff Discontinuous Galerkin Scheme With Limiters That Guarantees Moment-Realizability For Quadrature-Based Moment Closures, Christine Wiersma

Graduate Theses and Dissertations

A polydisperse multiphase flow is one in which one of the thermodynamic phases can be considered discrete while the other is assumed to be continuous. Examples include sprays and bubbly flows. Such flows can be modeled by kinetic models that describe the evolution of a probability density function (PDF) in phase space. Moments of this PDF describe physical observable quantities such as the mass, momentum, and energy in

the flow. From a computational perspective, kinetic models are expensive to solve since they require the resolution of a very high-dimensional phase space. In many polydisperse multiphase flow applications, the phase space ...


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 ...


Graphene Humidity Sensor With Gold Nanoparticles, Jiawei Bao Jan 2019

Graphene Humidity Sensor With Gold Nanoparticles, Jiawei Bao

Graduate Theses and Dissertations

Humidity sensors can be used to monitor body sweat. Here, we studied a humidity sensor that comprised of a graphene layer between two electrodes. The operating principle is that the humidity sensor will respond when vapor reaches the graphene layer from the top. Based on the humidity diffusion, the sensor measures the relative humidity (RH) with different response times. Graphene is a material with high diffusivity and small thickness that can increase the sensitivity of a sensor. Based on the Micro Electro Mechanical Systems (MEMS) method, we modeled the humidity sensor using COMSOL Multiphysics transport of diluted species software. Finally ...


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 ...


An Investigation Of An Ionic Liquid Analog To The Conventional Metal-Oxide-Semiconductor Field-Effect Transistor, Richard Effler Jan 2019

An Investigation Of An Ionic Liquid Analog To The Conventional Metal-Oxide-Semiconductor Field-Effect Transistor, Richard Effler

Graduate Theses and Dissertations

An ionic circuit analogous to a traditional metal-oxide semiconductor was investigated, using 1-ethyl-3-methylimidazolium trifluoromethanesulfonate as the ionic liquid in the gating element. The circuit was observed to perform with comparatively high threshold and overdrive voltages in a region below the saturation current of the transistor. The concept of the design was successfully verified, although further improvements in electrode positioning and manufacturing precision are warranted.


Optimizing Bioprosthetic Heart Valves Using Isogeometric Analysis And Surrogate Modeling, Jung Hyun Ha Jan 2019

Optimizing Bioprosthetic Heart Valves Using Isogeometric Analysis And Surrogate Modeling, Jung Hyun Ha

Graduate Theses and Dissertations

Various studies in the biomechanics field have been conducted to analyze the aortic valvular disease and develop prosthetic heart valves. Optimization is an efficient solution to improve prosthetic heart valve performance. This thesis aims to optimize the bioprosthetic heart valve design to increase the coaptation area during the diastole and the orifice area during the systole. Large coaptation area prevents some possibilities of aortic regurgitation, and large orifice area increases the blood flow efficiency from the left ventricle to the aorta. The proposed solution for optimizing aortic heart valve design includes the surrogate management framework, which is a derivative-free pattern ...


Optimization Of Multi-Injection Diesel Combustion Through Direct Application Of Abc And Pso Variant Algorithms, Ryan Michael Ogren Jan 2019

Optimization Of Multi-Injection Diesel Combustion Through Direct Application Of Abc And Pso Variant Algorithms, Ryan Michael Ogren

Graduate Theses and Dissertations

In this study a modified artificial bee colony algorithm and the cooperative-swarm variant of particle swarm optimization were applied to minimize diesel engine emissions and fuel consumption in the laboratory at medium load conditions. Tests were conducted using No. 2 diesel fuel in a four-cylinder, production diesel engine with series turbochargers and a high-pressure exhaust gas recirculation loop. Emissions were recorded at steady-state conditions and input into custom scripts in Matlab.

Both triple-injection strategies, consisting of a pilot-main-post injection scheme, and quadruple-injection strategies, using two pilots, were investigated for a high exhaust gas recirculation rate of 38%. A two-factor design ...


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 ...


Head Impact Simulation Using Coupled Eulerian-Lagrangian Approach, Miao Na Jan 2019

Head Impact Simulation Using Coupled Eulerian-Lagrangian Approach, Miao Na

Graduate Theses and Dissertations

As a major cause of death and disability, traumatic brain injury (TBI) creates considerable burdens to society due to high economic costs. Accordingly, investigation into the common causes of TBI such as dynamic head impact problems is of great importance in order to further understand the injury mechanisms, precisely diagnose the level of the injuries, and develop effective prevention methods. Finite element (FE) method has been widely used for gaining insights into the mechanical response of brain tissue during impacts, yet there are still computational challenges to be addressed and severe mesh distortion effect in the cerebrospinal fluid (CSF) is ...


Computational Analysis And Design Of The Morphology Of Organic Solar Cells, Ramin Noruzi Jan 2019

Computational Analysis And Design Of The Morphology Of Organic Solar Cells, Ramin Noruzi

Graduate Theses and Dissertations

Projected increases in energy demand and increasing global concern regarding climate change

have focused research attention on renewable, clean energy sources, such as organic solar cells

(OSCs). OSCs based on blend of electron donating conjugate polymers and electron accepting

fullerene materials have potential to be a disruptive technology within the solar cell market. OSCs

have several advantages over their inorganic counterparts. The materials used in most OSCs are

flexible, allowing for easier transport and installation of such devices. However, because of

OSCs main deficiency of significantly low photocurrent generation, they have not yet seen mass

adoption in industry. The problem ...


Placenta-On-A-Chip: A Microfluidic Platform To Study The Drug Transport Across The Human Placental Barrier, Rajeendra Lakruwan Pemathilaka Jan 2019

Placenta-On-A-Chip: A Microfluidic Platform To Study The Drug Transport Across The Human Placental Barrier, Rajeendra Lakruwan Pemathilaka

Graduate Theses and Dissertations

The human placenta is a gender-specific, interim endocrine organ that grows in the uterus during pregnancy, with the placenta attaching the evolving fetus to the uterine wall through the umbilical cord to supply oxygen and nutrients. The placenta is also responsible for facilitating removal of waste products and carbon dioxide from the fetus, and with protecting the fetus from infectious agents and foreign substances that can be introduced across the placental barrier. Until the revelation of thalidomide-induced birth defects in the late 1960s, the human placenta was assumed to be an impenetrable barrier shielding the fetus from xenobiotics transfused from ...


Machine Learning Assisted Optimization With Applications To Diesel Engine Optimization With The Particle Swarm Optimization Algorithm, Aaron M. Bertram Jan 2019

Machine Learning Assisted Optimization With Applications To Diesel Engine Optimization With The Particle Swarm Optimization Algorithm, Aaron M. Bertram

Graduate Theses and Dissertations

A novel approach to incorporating Machine Learning into optimization routines is presented. An approach which combines the benefits of ML, optimization, and meta-model searching is developed and tested on a multi-modal test problem; a modified Rastragin's function. An enhanced Particle Swarm Optimization method was derived from the initial testing. Optimization of a diesel engine was carried out using the modified algorithm demonstrating an improvement of 83% compared with the unmodified PSO algorithm. Additionally, an approach to enhancing the training of ML models by leveraging Virtual Sensing as an alternative to standard multi-layer neural networks is presented. Substantial gains were ...


Animated Rendering Of Cardiac Model Simulations, Xin Huang Jan 2019

Animated Rendering Of Cardiac Model Simulations, Xin Huang

Graduate Theses and Dissertations

Heart disease has been the leading cause of death both in the world and the United States

in the past decade. Computational cardiac modeling and simulation, especially patient-specific

cardiac modeling has been recognized as one of the best ways to improve diagnosis of heart

disease by providing insights in individual disease characteristics that cannot be obtained by

other means. However presenting the results of cardiac simulations to cardiologists in an

interactive manner can considerably improve the utility of cardiac models in understanding

the heart function. In this work, we have developed virtual reality and animated volume

rendering techniques to render ...


Automated Approaches For The Construction Of Image Based Phase Diagrams, Badrinath Balasubramaniam Jan 2019

Automated Approaches For The Construction Of Image Based Phase Diagrams, Badrinath Balasubramaniam

Graduate Theses and Dissertations

In the field of materials science, phase diagram construction is often a laborious process because of the time taken for a human to sift through a large number of images. To mitigate this, machine learning approaches have been used by researchers to automate the construction of these phase diagrams using both supervised and unsupervised learning. In this dissertation, I have outlined a step-wise lego-like approach using both unsupervised learning and image processing approaches to automate the construction of image based phase diagrams and have illustrated that with the construction of three polymer phase diagrams.