Engineering Commons^™

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 …

Enhancing Bioethanol Fermentation Through Removal Of Acetic Acid Using Liquid-Liquid Extraction, Mahdieh Aghazadeh

Open Access Dissertations

The concern for the ever growing human population as well as the depletion of fossil fuel resources and their impact on global warming have long been motivations for the researchers to investigate means for sustainable producing carbon-neutral energy. Second-generation biofuel refers to liquid fuels that are produced from non-food resources and reduce the total greenhouse gas emission by at least 60 %. Acetic acid has been shown to be one of the most ubiquitous fermentation inhibitors in a bioethanol production facility which slows down the bioethanol production and reduces its yield through inhibition of the ethanol producing microorganisms. The use …

Improving The Mechanistic Study Of Neuromuscular Diseases Through The Development Of A Fully Wireless And Implantable Recording Device, Rebecca A. Bercich

Open Access Dissertations

Neuromuscular diseases manifest by a handful of known phenotypes affecting the peripheral nerves, skeletal muscle fibers, and neuromuscular junction. Common signs of these diseases include demyelination, myasthenia, atrophy, and aberrant muscle activity—all of which may be tracked over time using one or more electrophysiological markers. Mice, which are the predominant mammalian model for most human diseases, have been used to study congenital neuromuscular diseases for decades. However, our understanding of the mechanisms underlying these pathologies is still incomplete. This is in part due to the lack of instrumentation available to easily collect longitudinal, in vivo electrophysiological activity from mice. There …

On The 3d Point Cloud For Human-Pose Estimation, Kai-Chi Chan

Open Access Dissertations

This thesis aims at investigating methodologies for estimating a human pose from a 3D point cloud that is captured by a static depth sensor. Human-pose estimation (HPE) is important for a range of applications, such as human-robot interaction, healthcare, surveillance, and so forth. Yet, HPE is challenging because of the uncertainty in sensor measurements and the complexity of human poses. In this research, we focus on addressing challenges related to two crucial components in the estimation process, namely, human-pose feature extraction and human-pose modeling.

In feature extraction, the main challenge involves reducing feature ambiguity. We propose a 3D-point-cloud feature called …

A Transfer Network Linking Earth, Moon, And The Triangular Libration Point Regions In The Earth-Moon System, Lucia R. Capdevila

Open Access Dissertations

In the near future, several space applications in the Earth-Moon system may require a spacecraft to hold a stable motion, but the transfer trajectory infrastructure to access such stable motions has not been fully investigated yet. The triangular libration points, L 4and L5, in the Earth-Moon system have long been thought of as ideal locations for a communications satellite. Recently, Distant Retrograde Orbits (DROs) and Near-Rectilinear Halo Orbits (NRHOs) near the Moon have been identified as motion of interest for manned and unmanned missions with a focus on operations in cislunar space. The triangular libration points, as well as …

Is Metabolism Goal-Directed? Investigating The Validity Of Modeling Biological Systems With Cybernetic Control Via Omic Data, Frank T. Devilbiss

Open Access Dissertations

Cybernetic models are uniquely juxtaposed to other metabolic modeling frameworks in that they describe the time-dependent regulation of cellular reactions in terms of dynamic "metabolic goals." This approach contrasts starkly with purely mechanistic descriptions of metabolic regulation which seek to explain metabolic processes in high resolution — a clearly daunting undertaking. Over a span of three decades, cybernetic models have been used to predict metabolic phenomena ranging from resource consumption in mixed-substrate environments to intracellular reaction fluxes of intricate metabolic networks. While the cybernetic approach has been validated in its utility for the prediction of metabolic phenomena, its central feature, …

Rearward Visibility Issues Related To Agricultural Machinery: Contributing Factors, Potential Solutions, Shawn Gregory Ehlers

Open Access Dissertations

As the size, complexity, and speed of tractors and other agricultural self-propelled machinery have increased, so have the visibility-related issues, placing significant importance on the visual skills, alertness, and reactive abilities of the operator. Rearward movement of large agricultural equipment has been identified in the literature as causing not only damage to both machine and stationary objects, but also injuries (even fatalities) to bystanders not visible to the operator. Fortunately, monitoring assistance, while not a new concept, has advanced significantly, offering operators today more options for increasing awareness of the area surrounding their machines. In this research, an attempt is …

Ultra-Thin Boron Nitride Films By Pulsed Laser Deposition: Plasma Diagnostics, Synthesis, And Device Transport, Nicholas Robert Glavin

Open Access Dissertations

This work describes, for the first time, a pulsed laser deposition (PLD) technique for growth of large area, stoichiometric ultra-thin hexagonal and amorphous boron nitride for next generation 2D material electronics. The growth of boron nitride, in this case, is driven by the high kinetic energies and chemical reactivities of the condensing species formed from physical vapor deposition (PVD) processes, which can facilitate growth over large areas and at reduced substrate temperatures. The use of optical emission spectroscopy during plasma growth provides insight into chemistry, kinetic energies, time of flight data, and spatial distributions within a PVD plasma plume ablated …

Coupled Orbit-Attitude Mission Design In The Circular Restricted Three-Body Problem, Davide Guzzetti

Open Access Dissertations

Trajectory design increasingly leverages multi-body dynamical structures that are based on an understanding of various types of orbits in the Circular Restricted Three-Body Problem (CR3BP). Given the more complex dynamical environment, mission applications may also benefit from deeper insight into the attitude motion. In this investigation, the attitude dynamics are coupled with the trajectories in the CR3BP. In a highly sensitive dynamical model, such as the orbit-attitude CR3BP, periodic solutions allow delineation of the fundamental dynamical structures. Periodic solutions are also a subset of motions that are bounded over an infinite time-span (assuming no perturbing factors), without the necessity to …

Influence Of The 3d Microenvironment On Glioblastoma Migration And Drug Response, Ruth Marisol Herrera Perez

Open Access Dissertations

Glioblastoma (GBM) is a highly invasive brain cancer characterized by poor prognosis. Despite significant efforts by the basic and clinical research community our understanding of GBM progression and recurrence has been incremental. Improvements in therapeutic response have been dismal, and GBM continues to be the deadliest tumor of the central nervous system, with patient average survival rate of 12 months. Synergistic relationships that the tumor cells establish with the brain microenvironment have been proven fundamental for successful tumor progression and maintenance. Yet, many in vitro GBM studies are performed in formats that fail to recapitulate the most essential component of …

Optimal Monitoring And Mitigation Of Systemic Risk In Lending Networks, Zhang Li

Open Access Dissertations

This thesis proposes optimal policies to manage systemic risk in financial networks. Given a one-period borrower-lender network in which all debts are due at the same time and have the same seniority, we address the problem of allocating a fixed amount of cash among the nodes to minimize the weighted sum of unpaid liabilities. Assuming all the loan amounts and cash flows are fixed and that there are no bankruptcy costs, we show that this problem is equivalent to a linear program. We develop a duality-based distributed algorithm to solve it which is useful for applications where it is desirable …

Coupled Resonator Based Wireless Power Transfer For Bioelectronics, Henry Mei

Open Access Dissertations

Implantable and wearable bioelectronics provide the ability to monitor and modulate physiological processes. They represent a promising set of technologies that can provide new treatment for patients or new tools for scientific discovery, such as in long-term studies involving small animals. As these technologies advance, two trends are clear, miniaturization and increased sophistication i.e. multiple channels, wireless bi-directional communication, and responsiveness (closed-loop devices). One primary challenge in realizing miniaturized and sophisticated bioelectronics is powering. Integration and development of wireless power transfer (WPT) technology, however, can overcome this challenge.

In this dissertation, I propose the use of coupled resonator WPT for …