Engineering Commons^™

A Study Of Inkjet Printed Line Morphology Using Volatile Ink With Non-Zero Receding Contact Angle For Conductive Trace Fabrication, Chenchao Shou

Open Access Theses

Inkjet printed lines on a homogeneous solid substrate are studied under the condition that ink evaporation is not negligible and the contact angle exhibits hysteresis with non-zero receding contact angle (NRCA). A new family of line instability is discovered, featured by formation of agglomerations within a line. The agglomeration is explained by a hydrodynamic flow that consistently drives a bead on the substrate towards fresh deposited droplets due to concentration-induced surface tension gradient. Morphologies of lines printed with multiple layers are also explored for the purpose of conductive trace fabrication. A non-uniform morphology is observed across a multi-layer line when …

Modeling The Dynamics Of Household-Level Hurricane Evacuation Timing Decisions, Md. Tawfiq Sarwar

Open Access Theses

Frequent occurrences of hurricanes in the coastal areas of the United States in recent times have indicated the necessity of comprehensive evacuation planning. Failure to ensure efficient and timely evacuation causes devastating impacts including loss of lives and property damages. In order to ensure efficient evacuation, emergency officials need to understand how households make evacuation decisions and how their decisions can be influenced. Households' decisions to evacuate/stay, time of departure, route choice and destination choice are four fundamental behavioral issues in the evacuation process. In this thesis, we develop a joint modeling approach for both household-level evacuation decision and departure …

Investor Sentiment In The Stock Market, Bayram Veli Salur

Open Access Theses

Classical finance theories neglect the impact of investor sentiment on stock returns. These theories assume that investors are rational and make decisions in a way that maximizes their wealth. However, a vast amount of research shows that investors' decisions are affected by their psychological biases and feelings. These findings suggest that investor sentiment may have an impact on stock returns. This hypothesis is the main motivation of this study. First, this study examines whether there is correlation among investor sentiment indicators, and whether sentiment indicators have an impact on stock returns in the US and other countries. Second, this study …

Finfet Device Optimization At 15nm For Near-Threshold Operation, Jolene Singh

Open Access Theses

Much of the current research in the electronic industry focuses on reducing power consumption of digital circuits. Towards the same many attempts are being made to reduce the operating voltage of the circuits. It has been shown through device and circuit analysis that a circuit consumes minimum energy when operated near threshold voltage. In this thesis I vary device parameters and study their effects on energy consumption and delay of the device for the two regions of operation - superthreshold and near-threshold, using LUTs of IV and CV characteristics, verilogA and hSpice. Finally, device parameters are obtained for an optimum …

Modulation Of Cell-Matrix Interaction For Cryopreservation Of Engineered Tissue, Angela Christine Seawright

Open Access Theses

Long term preservation of functional engineered tissues can significantly advance tissue engineering industry and regenerative medicine. Several preservation techniques have been proposed and investigated for this purpose, and cryopreservation is a leading candidate. While tissues are cryopreserved, ice forms in both the extracellular and intracellular spaces and causes freezing-induced spatiotemporal deformation of the tissue. During this process the cells undergo dehydration by the freezing-induced osmotic pressure difference and mechanical deformation, transmitted through cell-extracellular matrix adhesions. However, the significance and interaction of these cellular level transport and mechanics processes are not well understood. Therefore, this study aims to establish mechanistic understanding …

Combining Multiple, Inexpensive Gps Receivers To Increase Accuracy And Reliability, Daniel Kenneth Schrader

Open Access Theses

GPS is a technology that allows for accurate tracking of various parameters, namely speed and location. Many modern systems and tools require a rapidly-refreshing report of their speed and/or location, but the GPS technology available to most users may not be accurate enough for some applications. Methods currently

exist to improve GPS accuracy, but many or all of these methods are expensive, difficult, or simply not available without special technology and permission.

The research presented in this thesis describes an attempt to improve the accuracy and/or reliability of GPS, without using any expensive or restricted methods. The ability for any …

Operational Modal Analysis And Force Characterization Of An Unstable Liquid Rocket Engine, Kevin Charles Buechele

Open Access Theses

Combustion instability has plagued the rocket industry since its beginnings. It is characterized by sustained pressure oscillations in the combustion chamber due to the coupling of natural pressure fluctuations with unsteady heat release. Typically, combustion instabilities are identified and mitigated during ground testing. Occasionally combustion instabilities do not present themselves until after a system is fielded and may only occur in a flight environment. While ground tests are heavily instrumented, operational flight data may not contain any direct measurement of the combustion forcing function. Post-event efforts to characterize anomalous combustion instabilities with existing instrumentation have had little success.

Accelerometers, which …

Development And Benefit Analysis Of A Sector Design Algorithm For Terminal Dynamic Airspace Configuration, Vincent Joseph Sciandra

Open Access Theses

The National Airspace System (NAS) is the vast network of systems enabling safe and efficient air travel in the United States. It consists of a set of static sectors, each controlled by one or more air traffic controllers. Air traffic control is tasked with ensuring that all flights can depart and arrive on time and in a safe and efficient matter. However, skyrocketing demand will only increase the stress on an already inefficient system, causing massive delays. The current, static configuration of the NAS cannot possibly handle the future demand on the system safely and efficiently, especially since it is …

Analysis Of Cyberattacks On Unmanned Aerial Systems, Andrew Morris Shull

Open Access Theses

With the increasing power and convenience offered by the use of embedded systems in control applications, such systems will undoubtedly continue to be developed and deployed. Recently, however, a focus on data-centric systems and developing network-enabled control systems has emerged, allowing for greater performance, safety, and resource allocation in systems such as smart power grids and unmanned military aircraft. However, this increase in connectivity also introduces vulnerabilities into these systems, potentially providing access to malicious parties seeking to disrupt the operation of those systems or to cause damage. Given the high potential cost of a failure in these systems in …

Interactive Multivariate Data Exploration For Risk-Based Decision Making, Silvia Oliveros Torres

Open Access Theses

Risk-based decision making is a data-driven process used to gather data about outcomes, analyze different scenarios, and deliver informed decisions to mitigate risk.

An interactive visual analytics system can help derive insights from large amounts of data and facilitate the risk management process thereby providing a suitable solution to examine different decision factors. This work introduces two separate systems that

incorporate visual analytics techniques to help the users in the tasks of identifying patterns, finding correlations, designing mitigation strategies, and assisting in the long term planning and assessment process. The first system looks at the National Health

and Nutrition Examination …

Examining The Effects Of Computational Tools On Students' Conceptual Understanding Of Thermodynamics Of Material Concepts And Representations, Oyindamola Oluwatimi

Open Access Theses

Technology is becoming a more critical agent for supporting learning as well as research in science and engineering. In particular, technology-based tools in the form of simulations and virtual environments support learning using mathematical models and computational methods. The purpose of this research is to: (a) measure the value added in conveying Thermodynamics of materials concepts with a blended learning environment using computational simulation tools with lectures; and (b) characterize students' use of representational forms to convey their conceptual understanding of core concepts within a learning environment that blended Gibbs computational resource and traditional lectures.

A mix-method approach was implemented …

Flow And Heat Transfer In An L-Shaped Cooling Passage With Ribs And Pin Fins For The Trailing Edge Of A Gas-Turbine Vane And Blade, Irsha Ashok Pardeshi

Open Access Theses

Efficient and effective cooling of the trailing edges of gas-turbine vanes and blades is challenging because there is very little space to work with. In this study, CFD simulations based on steady RANS closed by the shear-stress transport turbulence model were performed to study the flow and heat transfer in an L-shaped duct for the trailing edge under two operating conditions. One operating condition, referred to as the laboratory condition, where experimental measurements were made, has a Reynolds number at the duct inlet of Re_D = 15,000, coolant inlet temperature of T_inlet = 300 K, wall temperature of …

An Evaluation Of Spatial Variability Of Water Stress Index Across The United States: Implications Of Supply And Demand In The East Vs The West, Jennifer Ann Roath

Open Access Theses

In order to support both human and environmental needs, high quality fresh water must be available when and where it is required. As a metric for indicating unsustainable water usage, WSI is only useful when the values reflect accurate interactions between supply and demand; however, the complexity of temporal and spatial variability of available fresh water complicates the analysis of water stress.

The overall goal of this project was to investigate the spatial variability of water stress across the United States and the appropriate spatial scale for management decisions. To accomplish this, a national dataset describing spatial distribution and breakdown …

Performance-On-Demand Mems (Podmems): Electrical Control Of Effective Mass, Damping, And Stiffness, Shehrin Sayed

Open Access Theses

We propose the use of electrostatic force feedback to control the stiffness, damping, or mass of MEMS. If feedback forces are proportional to sensed displacement, velocity, or acceleration of a MEMS proof mass, then feedback can be used to increase or decrease the apparent stiffness, damping, and or mass of the MEMS. Such feedback can be used to compensate for process variations, packaging stress, thermal drift, viscous damping, etc. Prior efforts by others include position or velocity based feedback for modifying frequency, bandwidth, quality factor, or sensitivity of resonators. We present a means of quantitative control of stiffness, damping, and …

Laboratory Testing Of Railroad Flatcars For Use As Highway Bridges On Low-Volume Roads To Determine Ultimate Strength And Redundancy, Teresa Lynn Washeleski

Open Access Theses

Railroad flatcars (RRFCs) are a convenient option to replace existing deteriorating bridge structures on low-volume roads. They are typically used as the bridge superstructure by placing two or more flatcars side-by-side to achieve the desired bridge width. Utilizing RRFCs as a bridge allows for rapid construction and greater cost savings compared to traditional practices. These benefits make them an attractive solution for rural communities in Indiana, as well as other states.

Uncertainty remains about the response under higher loads than could be easily achieved in the field and the level of redundancy of railroad flatcar bridges. Using RRFCs as bridges …

Quantum Computing With Steady State Spin Currents, Brian Matthew Sutton

Open Access Theses

Many approaches to quantum computing use spatially confined qubits in the presence of dynamic fields to perform computation. These approaches are contrasted with proposals using mobile qubits in the presence of static fields. In this thesis, steady state quantum computing using mobile electrons is explored using numerical modeling. Firstly, a foundational introduction to the case of spatially confined qubits embodied via quantum dots is provided. A collection of universal gates implemented with dynamic fields is described using simulations. These gates are combined to implement a five-qubit Grover search to provide further insight on the time-dependent field approach. Secondly, the quantum …

The Design And Evaluation Of A 5.8 Ghz Laptop-Based Radar System, Kevin Chi-Ming Teng

Open Access Theses

This project involves design and analysis of a 5.8 GHz laptop-based radar system. The radar system measures Doppler, ranging and forming Synthetic Aperture Radar (SAR) images utilizing Matlab software provided from MIT Open Courseware and performs data acquisition and signal processing. The main purpose of this work is to bring new perspective to the existing radar project by increasing the ISM band frequency from 2.4 GHz to 5.8 GHz and to carry out a series of experiments on the implementation of the radar kit. Demonstrating the radar at higher operating frequency is capable of providing accurate data results in Doppler, …

Rheological Properties Of Gluten Free Dough Systems, Stephany Aurea Tandazo

Open Access Theses

Bread is the one of the oldest processed foods and a major wheat based product. The basic process involves mixing of ingredients until the flour is converted into dough, followed by baking the dough into a loaf. A very important step in breadmaking is to know how to make good quality dough. However, the increasing knowledge of people being diagnosed with celiac disease (gluten intolerance) has encouraged scientists to develop healthier and better quality gluten-free products that would greatly improve the quality of life of celiac patients. The main objective of this study was to create a dough system composed …

Strategy For Health Monitoring And Fault Detection In Heavy-Duty Diesel Engines, Aniketjayant Vagha

Open Access Theses

Performance tuning, health monitoring, fault diagnosis, etc. are important aspects of testing a pre-production engine out in the field. To fulfill these tasks, a robust data-based strategy for detecting anomalies in diesel engines is proposed in this work. Such a strategy separates the healthy data from outlying, anomalous trends of faulty data. The data classifier used here is based on fundamental principles of statistical learning and derived from linear discriminant analysis.

Further efforts to improve the classification performance led to the finding that steady state data makes for a more accurate classification of the working conditions of individual trucks. Hence …

Evaluating Different Bridge Management Strategies Using The Bridge Management Research System (Bmrs), Timothy Paul Stroshine

Open Access Theses

This project investigated the effects of varying two different elements of bridge management strategies. The first element was a trigger value (an NBI condition rating for a bridge component) at which a maintenance treatment can be performed. The second element was the budget.

A new software program, the Bridge Management Research System (BMRS), was created to test these elements of bridge management strategies for Indiana's bridge network. BMRS is a simplified version of a previous bridge management software package developed by Purdue University, the Indiana Bridge Management System (IBMS). To test variations in the trigger values, three different bridge management …

Health Diagnosis Of Lithium-Ion Battery Cell Using Vibration-Based Test And Analysis, Huan Le Pham

Open Access Theses

With their superior advantages of high capacity and low percentage of self-discharge, lithium-ion batteries, which are most commonly used as power sources for hand-held electronic devices, have become the most popular choice for power storage in electric vehicles. Due to the increased potential for long life of lithium-ion batteries in vehicle applications, manufacturers are pursuing methodologies to increase the reliability of their batteries. Methods are now being developed to monitor the health of lithium-ion batteries throughout their life cycle. The work in this thesis is focused on utilizing non-destructive vibration diagnostic testing methods to monitor changes in the physical properties …

Modeling Of Legged Locomotion With A Suspended Load In The Sagittal Plane, Karna P. Potwar

Open Access Theses

Walking or running while carrying loads has always been a tedious task, more so when the loads are heavy. Such a task of carrying loads not only requires extra effort but also leads to physical pain and in some cases injury. Prior studies on human locomotion with a suspended load have used models that are restricted in their DOFs and so are not able to take into account the fore aft movement in human beings. The objective of this thesis is to model the dynamics of sagittal plane center-of-mass locomotion with a suspended load and apply findings to carrying loads …

Chemical Consequences Of Chicxulub Impact Ejecta Reentry, Devon Donald Parkos

Open Access Theses

The Chicxulub impact 66.0 million years ago initiated the second biggest extinction in the Phanerozoic Eon. The global reentry of material ejected by the impact generated a strong pulse of thermal radiation that wiped out much of the terrestrial biota. The cause of the marine extinction, however, has remained elusive. This report shows that reentering ejecta produces enough NOx to acidify the upper ocean and cause a massive marine extinction. Using non-equilibrium chemically reacting flow simulations coupled with atmospheric transport modeling, it is determined that enough NOx reached the stratosphere and precipitated to overpower the carbonate buffer and acidify the …

Evaluation Of Vertical Profiles To Design Continuous Descent Approach Procedure, Pradeep Priyank

Open Access Theses

The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics …

Development Of A Counter Rotating Vortex Pair (Cvp) Mixer For Aerospace Applications, Jeongmoon Park

Open Access Theses

Swirling motions induced by a counter-rotating vortex pair (CVP) provides a mechanism to entrain fluid from the periphery of this structure and mix surrounding fluids with those within the vortex structure. Eventually, the vortices act upon each other transporting molecularly mixed fluid into the core flow. This mechanism has potential to increase efficiency with more complete mixing. Therefore, a mixer is proposed which directly induces counter rotating vortices by a three dimensional geometry. The proposed swirl mixer is designed to induce counter rotating vortices based on the potential flow theory, Milne-Thomson's Circle Theorem and Rankine vortex. Twelve test models are …

Nutrient Recovery From Anaerobically-Digested Dairy Manure By Struvite Formation And Its Effect On Gas Releases, Zhong Qiao

Open Access Theses

Manure management practices such as anaerobic digestion and lagoon storage have become important issues for large dairy farms partially due to water quality and air quality concerns caused by excess nitrogen and phosphorus. Prior research efforts have proven that struvite formation is an effective method for nutrients recovery from both municipal and agricultural wastewaters. However, little is known about nutrient recovery through struvite formation from anaerobically-digested dairy manure effluents.The effects of struvite precipitation on the releases of gases such as NH3, H2S, and CO2 are also unclear.

In this thesis, both bench-scale tests and pilot-scale storage tests were conducted to …

Analysis Of An Actuated Two Segment Leg Model Of Locomotion, Nikhil Vinayak Rao

Open Access Theses

Research studies on dynamic models of legged locomotion have generally focused on telescoping-type leg models. Such telescoping spring loaded inverted pendulum (SLIP) models have been able to accurately predict observed center of mass (CoM) trajectories. There have been comparatively fewer studies on dynamics of locomotion

with segmented legs. Some earlier studies on the dynamics due to leg segmentation appear straightforward. For example, a simple model with the only joint moment being due to a passive springy knee has been shown to behave similarly to a telescoping spring-mass model. However, in real-life animal locomotion, there are multiple joint-moments acting at the …

A Mechanism Design Approach To Bandwidth Allocation In Tactical Data Networks, Ankur Mour

Open Access Theses

The defense sector is undergoing a phase of rapid technological advancement, in the pursuit of its goal of information superiority. This goal depends on a large network of complex interconnected systems - sensors, weapons, soldiers - linked through a maze of heterogeneous networks. The sheer scale and size of these networks prompt behaviors that go beyond conglomerations of systems or `system-of-systems'. The lack of a central locus and disjointed, competing interests among large clusters of systems makes this characteristic of an Ultra Large Scale (ULS) system. These traits of ULS systems challenge and undermine the fundamental assumptions of today's software …

Rotor Blade Operational Data Analysis Methods And Applications For Health Monitoring Of Wind Turbines Using Integrated Blade Sensing, Noah Jacob Myrent

Open Access Theses

Wind energy is one of the fastest growing sources of power production in the world today. In order to extract the maximum potential amount of energy from the wind, a wind turbine's reliability must be a top priority. As utility scale wind turbines increase in size and initial capital investment cost, there also comes an increasing need to monitor the health of the turbine. Currently, most wind turbines do not incorporate blade mounted inertial sensing in addition to blade strain measurements. This approach has the potential to detect inevitable blade damage types early on so that a maintenance schedule can …

Simulating Land Use Land Cover Change Using Data Mining And Machine Learning Algorithms, Amin Tayyebi

Open Access Dissertations

The objectives of this dissertation are to: (1) review the breadth and depth of land use land cover (LUCC) issues that are being addressed by the land change science community by discussing how an existing model, Purdue's Land Transformation Model (LTM), has been used to better understand these very important issues; (2) summarize the current state-of-the-art in LUCC modeling in an attempt to provide a context for the advances in LUCC modeling presented here; (3) use a variety of statistical, data mining and machine learning algorithms to model single LUCC transitions in diverse regions of the world (e.g. United States …