Engineering Commons^™

Utilizing Tunable Signal Interference Control Topologies With Electromechanical Resonators, Bryce A. Geesey

Open Access Theses

Exploiting knowledge gained from previous investigations of channelized and trans-versal filters, signal interference filters use transmission line differences to generate transmission zeros through phase-shifted combinations of signals at the output of a device. The transmission lines used in these circuits are straightforward to design, but are limited to high-frequency signals (on the order of a few gigahertz) due to the necessity for spatial compactness and low loss. More recent studies have used electromechanical resonators to achieve phase shifting and quality factor improvements at slightly-lower frequencies. These concepts may prove useful if extended to micro- and nanoscale resonators.

To explore signal …

The Effect Of Confinement On The Development Of An Axisymmetric Wall Jet In Confined Jet Impingement, Tianqi Guo

Open Access Theses

Impinging jets have been widely used in the industry for cooling, heating, drying and many other purposes due to their excellent level of mass and heat transfer capacities. When issued into a confinement gap fully filled with working liquid, which is a typical configuration for the compact cooling devices designed to handle the extremely high heat fluxes generated by continuously working electronic components, they are classified as submerged confined impingement jets. Though the complicated flow field induced by the jet has attracted enormous amount of research efforts from heat transfer as well as fluid dynamics points of view, many key …

Phase Of Flight Identification In General Aviation Operations, Valentine Pascale Goblet

Open Access Theses

Identifying phases of flight in General Aviation can help in identifying safety events, which are events which may result in the aircraft being in a hazardous state. Unlike commercial operations that have well-defined phases of flight such as taxi, takeoff, climb, cruise, descent, approach, and landing, GA missions have more hard-to-identify phases of flight. For example, pilot training missions can involve multiple “touch-and-go” maneuvers, which make it difficult to define a distinct cruise phase during the patterns. Here, we present an algorithm to automatically identifying phases of flight in GA. The method includes an algorithm to tailor the phase of …

Mixed Mesh/Nodal Magnetic Equivalent Circuit Modeling Of A Six-Phase Claw-Pole Automotive Alternator, Daniel C. Horvath

Open Access Theses

Magnetic equivalent circuits (MECs) have been employed by many researchers to model the relationship between magnetic flux and current in electromagnetic systems such as electric machines, transformers and inductors [1] ,[2]. Magnetic circuits are analogous to electric circuits where voltage, current, resistance and conductance are the respective counterparts of magneto-motive force (MMF), magnetic flux, reluctance and permeance. The solution of MECs can be accomplished with the plethora of techniques developed for electrical circuit analysis. Specifically, mesh analysis, based on Kirchoff’s Voltage Law (KVL), and nodal analysis, based on Kirchoffs Current Law (KCL), are two very common solution techniques. Once an …

User-Centric Workload Analytics: Towards Better Cluster Management, Suhas Raveesh Javagal

Open Access Theses

Effective management of computing clusters and providing a high quality customer support is not a trivial task. Due to rise of community clusters there is an increase in the diversity of workloads and the user demographic. Owing to this and privacy concerns of the user, it is difficult to identify performance issues, reduce resource wastage and understand implicit user demands. In this thesis, we perform in-depth analysis of user behavior, performance issues, resource usage patterns and failures in the workloads collected from a university-wide community cluster and two clusters maintained by a government lab. We also introduce a set of …

Dynamic Green Split Optimization In Intersection Signal Design For Urban Street Network, Peng Jiao

Open Access Theses

In the past few decades, auto travel demand in the United States has significantly increased, but roadway capacity unfortunately has not expanded as quickly, which has led to severe levels of highway traffic congestion in many areas. In theory, the problem of congestion addressed through demand management and roadway expansion. However, system expansion in urban areas is difficult due to the extremely high cost of land; therefore, maximizing the existing capacity therefore often is considered the most realistic option. In urban areas, most of the traffic congestion and delays typically occur at signalized intersections. This thesis aims to prove the …

Modifications To Johanson's Roll Compaction Model For Improved Relative Density Predictions, Yu Liu

Open Access Theses

Johanson’s roll compaction model [J.R. Johanson, A rolling theory for granular solids, ASME Journal of Applied Mechanics E32 (1965) 842–848] is modified to improve its predictions of a compacted ribbon’s relative density. Previous work has shown that the maximum roll pressure and ribbon relative density predicted by the Johanson model are not only larger than those predicted from finite element method (FEM) simulations, but also unphysical in some cases. This over-prediction is due to a one-dimensional flow assumption in the Johanson model. Real powder velocity profiles within a roll compactor are non-uniform.

Johanson’s analysis is modified in this work to …

Dynamic Sensor Tasking And Imm Ekf Estimation For Tracking Impulsively Maneuvering Satellites, Arthur A. Lace

Open Access Theses

In order to efficiently maintain space situational awareness, care must be taken to optimally allocate expensive observation resources. In most situations the available sensors capable of tracking spacecraft have their time split between many different monitoring responsibilities. Tracking maneuvering spacecraft can be especially difficult as the schedule of maneuvers may not be known and will often throw off previous orbital models. Effectively solving this tasking problem is an ongoing focus of research in the area of space situational awareness. Most methods of automated tasking do not make use of interacting multiple model extended Kalman filter techniques to better track satellites …

Energy Dashboard For Real-Time Evaluation Of A Heat Pump Assisted Solar Thermal System, David Allen Lotz

Open Access Theses

The emergence of net-zero energy buildings, buildings that generate at least as much energy as they consume, has lead to greater use of renewable energy sources such as solar thermal energy. One example is a heat pump assisted solar thermal system, which uses solar thermal collectors with an electrical heat pump backup to supply space heating and domestic hot water. The complexity of such a system can be somewhat problematic for monitoring and maintaining a high level of performance. Therefore, an energy dashboard was developed to provide comprehensive and user friendly performance metrics for a solar heat pump system. Once …

Design Of An Asymmetric Reluctance Machine For A Generator Application, Bryan David Marquet

Open Access Theses

This work compares an Asymmetric Reluctance Machine (ARM) to a Uniform air Gap Reluctance Machine (UGRM) for a generator application. The ARM employs an asymmetric rotor pole to increase machine performance, specifically increasing torque density. A multi-objective optimization is employed to minimize mass and loss subject to design constraints. Two machines are compared in terms of their Pareto-optimal fronts.

Mining Big Data To Create A Tool For Empirical Observation Of Continuous Safety Improvement In A Construction Company - A Progressive Case Study In The Lean Environment, Nicolas J. Michuda

Open Access Theses

In any iterative process, without a system of measurement, controlled improvement cannot be recorded. This is especially true in the construction industry, where error occurs, often with fatal repercussions. As part of a process to facilitate the establishment of this metric, an entirely new application was created. The goal of this application is to measure the causal factors that lead to incidents, which will allow the user and administration to track the circumstances and types of incidents. This enables the company to focus on these problem areas and improve through training. By analyzing these incident trends over time, the company …

Investigating U.S. Resident Perceptions Of Corporate Social Responsibility In Food And Agriculture, Carissa Jae Morgan

Open Access Theses

Corporations are prioritizing corporate social responsibility (CSR) activities by investing in and actively promoting their social practices. In the U.S. of the modern food supply chain creates a unique challenge for corporations to address concerns about social issues of consumers and non-consumers alike. This study is motivated by the need to better understand individuals’ perceptions of CSR as it pertains to the food supply chain. In April 2015 an online survey collected information from 1,201 U.S. residents with the objective of investigating individuals’ perceptions of relative importance of eight prominent CSR areas relevant to food and agriculture. Demographic, household consumption, …

An Experimental Comparison Of Diffuser Designs In A Centrifugal Compressor, Cam-Tu Jeanne Methel

Open Access Theses

The objective of this investigation was to compare the effects of two different diffuser vane geometries on the performance of a centrifugal compressor. Vaned diffusers are commonly used in aeroengines because they can achieve higher pressure recoveries than vaneless diffusers of similar size. Improving the diffuser’s pressure recovery and effectiveness can result in overall compressor performance benefits that are sought out by engine manufacturers looking to improve overall engine efficiency. An airfoil vane was tested and compared to a baseline wedge diffuser in the Purdue CSTAR research facility, where the centrifugal compressor used for this study is intended to be …

Developing Agent-Based Simulation Models Of Task Performance Of Cognitively Diverse Teams, Megan Marie Nyre

Open Access Theses

Team-oriented work dominates industry, government, and academic areas with the goal of solving increasingly complex problems. However, the scope and external validity of traditional human factors research is inherently limited by the time and resources required to conduct laboratory studies. The model described in this thesis integrates simulation with human factors by providing an operationalized model that incorporates cognitive diversity and domain expertise. Convergence and functionality of the model have been established through a series of analyses, and a clear path for future research has been identified. By integrating simulation methods into human factors subject areas, researchers may be able …

Capacity Optimization Of Battery-Generator Hybrid Power System: Toward Minimizing Maintenance Cost In Expeditionary Basecamp/Operational Energy Applications, Jude C. Onwuanumkpe

Open Access Theses

Low and transient load condition are known to have deleterious impact on the efficiency and health of diesel generators (DGs). Extensive operation under such loads reduces fuel consumption and energy conversion efficiency, and contribute to diesel engine degradation, damage, or catastrophic failure. Non-ideal loads are prevalent in expeditionary base camps that support contingency operations in austere environments or remote locations where grid electricity is either non-existent or inaccessible. The impact of such loads on DGs exacerbates already overburdened basecamp energy logistics requirements. There is a need, therefore, to eliminate or prevent the occurrence of non-ideal loads. Although advances in diesel …

Analysis Of Body Force Effects On Flow Boiling And Condensation With Finite Inlet Quality, Lucas E. O'Neill

Open Access Theses

This study explores flow boiling pressure drop of FC-72 in a rectangular channel subjected to single-side and double-sided heating for vertical upflow, vertical downflow, and horizontal flow with positive inlet quality. Analysis of temporal records of pressure transducer signals is used to assess the influences of orientation, mass velocity, inlet quality, heat flux, and single-sided versus double-sided heating on magnitude of pressure drop oscillations, while fast Fourier transforms of the same records are used to capture dominant frequencies of oscillations. Time-averaged pressure drop results are also presented, with trends focusing on the competing influences of body force and flow inertia, …

A Methodology For Cooperation Between Electric Utilities And Consumers For Microgrid Utilization Based On A Systems Engineering Approach, Franklin E. Pacheco Chiguano

Open Access Theses

In recent years, the energy market has experienced important challenges in its structure and requirements of its actors, such as the necessity for more reliable electric service, energy efficiency, environmental care practices, and the incorporation of decentralized power generation based on distributed energy resources (DER). Given this context, microgrids offer several advantages to the grid and its actors. However, few microgrid projects have been implemented, and the participation of electric utilities is lower than the expected. Hence, this research explores how electric utility - customer interactions can accommodate mutual benefits for both parties through the proposal of a Microgrid Reference …

A Framework For Organizational Performance Assessment In The Construction Industry, Zenith Rathore

Open Access Theses

Organizations have been trying to increase their efficiency and improve their performance in order to achieve their goals. Organizational success is determined by various factors that impact organizational performance. Construction industry is a project based industry which is extremely dynamic in nature. The need to identify the weak points and search solutions to improve performance of construction organization is extremely crucial. Previous research works have primarily focused on the measurement of financial or tangible assets. Industry has always focused on measure of project success. However, previous studies lack the understanding of qualitative factors and their combine effect on organizational performance. …

Secondary Atomization Of Inelastic Non-Newtonian Liquid Drops In The Bag And Multimode Regimes, Jonathan Rocha

Open Access Theses

Secondary atomization of inelastic shear thinning non-Newtonian liquids in the bag and multimode regimes was studied. Six mixtures were formulated from deionized (DI) water, Avantor Performance Materials' USP grade 100% vegetable based glycerin, and Ashland's Carboxymethylcellulose (CMC-7MF or CMC-7HF). The resulting solutions had power law parameters flow behavior index, n, between 0.71 and 0.93 and consistency index, K, in the range of 0.0464 to 0.37 Pa·s n. The effective viscosity for each mixture was estimated using the power-law model and experimentally measured strain rates up to the initiation time.

Secondary atomization was achieved using a continuous jet setup. Breakup events …

Failure Pressure And Fatigue Analysis Of The Api 12f Shop Welded, Flat Bottom Tanks, Andres E. Rondon Andueza

Open Access Theses

This study investigates the failure pressure on the API 12F shop welded steel tanks and performs a fatigue evaluation to estimate the permissible number of pressure cycles for these equipment. Four different analyses were carried out on more than 350 finite element models to determine various failure pressure modes of these storage tanks. An elastic analysis considering potential buckling modes was developed to determine the yielding pressure of the tanks. The redistribution of stresses due to inelastic deformations and plastic collapse were evaluated through an elastic-plastic stress analysis considering the plastic hardening of the material. A wind load analysis was …

A Faster Version Of Louvain Method For Community Detection For Efficient Modeling And Analytics Of Cyber Systems, Sunanda Vivek Shanbhaq

Open Access Theses

Cyber networks are complex networks with various hosts forming the entities of the network and the communication between them forming the edges of the network. Most cyber networks exhibit a community structure. A community is a group of nodes that are densely connected with each other as compared to other nodes in the network. Representing an IP network in the form of communities helps in viewing the network from different levels of granularity and makes the visualization of the network cleaner and more pleasing to the eye. This will help significantly in cyber attack detection in large scale cyber networks. …

Transportation And Power Solutions For Africa: The Assessment And Optimization Of The Purdue Utility Platform, Jeremy Patrick Robison

Open Access Theses

The Purdue Utility Platform (PUP) is an off-road utility vehicle that was created to improve agricultural productivity in sub-Saharan Africa by providing appropriate transportation and mobile power solutions. The vehicle design has matured to a level where it now requires more robust engineering tools to perform a rigorous assessment of its function. The assessment will be pursued in two areas: durability of the frame and the roll stability of the vehicle. To assess the durability of the frame, a data acquisition system was installed to collect strain gauge information during the vehicle’s operation. This data was then related to an …

Consonant Discrimination In The Inferior Colliculus Of Young And Aged Rats, Christopher S. Soverns

Open Access Theses

Complex acoustic stimuli are thoroughly encoded and processed along the primary auditory pathway to give reliable and relevant information about the environment, and elucidating the neural coding mechanisms is essential to informing clinical attempts to combat auditory dysfuntion. Receiving a uniquely diverse set of ascending and descending inputs, the inferior colliculus (IC) is a site of intricate temporal processing. In this work, natural and modified human speech is used to investigate discrimination of voice onset time (VOT) in the spiking output of IC neurons. A template-matching classification model is proposed in which single stimulus presentation responses are correlated with aggregate …

Optimization Of Wireless Power Networks For Biomedical Applications, Kyle A. Thackston

Open Access Theses

Successful physiological integration of electronics will open the doors to new methods of treatment and diagnoses. One of the key challenges of this integration is designing devices as small as possible while still maintaining high functionality, such as bio-signal recording, processing, telemetry, and stimulation. Wireless power transfer (WPT) can help shrink a device’s footprint by removing the need for bulky batteries. While many modalities of WPT exist for biomedical applications, the optimal power transfer efficiency (PTE) is seldom achieved due to improper impedance matching. Existing methods for determining the optimal impedance matching conditions tend to be application specific and make …

Unsupervised Learning Framework For Large-Scale Flight Data Analysis Of Cockpit Human Machine Interaction Issues, Abhishek B. Vaidya

Open Access Theses

As the level of automation within an aircraft increases, the interactions between the pilot and autopilot play a crucial role in its proper operation. Issues with human machine interactions (HMI) have been cited as one of the main causes behind many aviation accidents. Due to the complexity of such interactions, it is challenging to identify all possible situations and develop the necessary contingencies. In this thesis, we propose a data-driven analysis tool to identify potential HMI issues in large-scale Flight Operational Quality Assurance (FOQA) dataset. The proposed tool is developed using a multi-level clustering framework, where a set of basic …

Effect Of Humidity On The Creep Response Of Cellulose Nanocrystals Films, Marianne C. Valone

Open Access Theses

Cellulose nanocrystals (CNCs) are a derivative of cellulose, the Earth’s most abundant source of a sustainable polymer. There are many applications for CNCs such as batteries, antimicrobial films, flexible displays and drug delivery. This research is focused on CNCs films and the mechanical properties once humidity was introduced.

The creation of self-aligned CNCs films was utilized to perform dynamic mechanical analysis (DMA) testing. The Forest Products Lab (FPL) in Madison, Wisconsin provided the CNCs used. Both 3.5 wt.% and 9.1 wt.% films were made and tested. A DMA method was created to test the creep response of the CNCs films …

Densified Collagen-Fibril Biomaterials For Bone Tissue Engineering, Lauren E. Watkins

Open Access Theses

Millions of craniofacial bone defects occur annually as a result of trauma, congenital defects, disease, or tooth extraction. When present in the oral cavity, these defects are associated with adverse impacts on speech, mastication, and aesthetics. Thus, there is a clinical need for interventional strategies to restore and preserve alveolar bone mass to improve the success of future treatment options intended to reestablish functionality and aesthetics. Guided bone regeneration using bone grafts and a membrane represent the current standard of care for repairing alveolar bone defects, but face a number of limitations related to resorption time and structural integrity. Improvements …

Targeted Metabolomics On The Shikimate And Aromatic Amino Acid Biosynthetic Pathways, Robert E. Wheeler

Open Access Theses

The shikimate and aromatic amino acid biosynthesis pathways are some of the most studied biosynthetic pathways in nature due to their fundamental importance. Interest in this field stems from synthesis of the essential amino acids, tryptophan, tyrosine and phenylalanine. The pathways also are important as generating the precursors of thousands of secondary metabolites and lignin. Inhibiting the pathway has led to discovery of herbicides, pesticides as well as tuberculosis drugs. However there is currently a lack of a comprehensive targeted method for detecting and quantifying the majority of the intermediates in these pathways. Often multiple extraction and detection methods are …

Tadpole Orbits In The L4/L5 Region: Construction And Links To Other Families Of Periodic Orbits, Alexandre G. Van Anderlecht

Open Access Theses

The equations of motion in the Circular Restricted Three-Body Problem (CR3BP) allow five equilibrium solutions, that is, the Lagrange or libration points. Two of the five equilibrium solutions are the triangular or equilateral libration points, L4 and L 5. As the secondary gravitational body moves in its orbit about the larger mass, L4 and L5 lead and trail the secondary by 60 degrees, respectively. This investigation focuses on periodic solutions in the vicinity of the triangular libration points, specifically horseshoe and tadpole orbits. Horseshoe orbits are symmetric periodic solutions in the plane of primary motion encompassing both …

A Case Study Of Two-Echelon Multi-Depot Vehicle Routing Problem, Tianqi Yu

Open Access Theses

The Vehicle Routing Problem (VRP) is a classic combinatorial optimization problem and a topic still studied for practical applications. Current research focuses on single echelon distribution systems such as distribution centers serving customers. However, in typical distribution, goods flows among regional distribution centers, local warehouses and customers, defined as a two-echelon network. The two-echelon multiple depot VRP problem is documented and applied to two stages illustrated by a small scale computational example. In the first stage, the simulated annealing algorithm is employed to determine the routes between local warehouses and final customers. For the second stage, trial-and-error is applied to …