Engineering Commons^™

Oxidation Of Ti2Alc In High Temperature Steam Environment, Ziyad M. Smoqi

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

High temperature oxidation of fuel cladding materials, during the loss of coolant accident (LOCA), is of utmost importance for next-generation nuclear energy systems. Ti₂AlC is a promising candidate material for nuclear applications due to its outstanding properties such as thermal stability at high temperatures, oxidation resistance in air, thermal shock resistance, low neutron absorption cross-section, and the resistance to irradiation-induced amorphization. In this research, high temperature steam oxidation experiments were conducted to evaluate the oxidation resistance of Ti₂AlC in LOCA conditions. After oxidation in 100% steam at 600 and 800˚C, the oxidation kinetics followed a parabolic …

The Professional Constructor, Full Issue, Volume 42, Number 01

The Professional Constructor

No abstract provided.

The Future Of Social Media Usage For Scholarly Research, Brent D. Bowen, Jackie Luedtke, Timothy B. Holt, David Ehrensperger, Hunter M. Watson

Publications

The research method for this project – examining the dissemination of research artifacts through social media as well as the impact social media can have on scholarly research – originated with Dr. Brent Bowen of Embry-Riddle Aeronautical University at the Prescott, Arizona campus and Dr. Dean E. Headley of Wichita State University. Drs. Bowen and Headley introduced the Airline Quality Rating (AQR) in early 1991 as an objective method for comparing and scoring airline performance in areas deemed to be important for consumers. Scores are calculated by defining 15-elements in four major areas, focusing on airline performance and the significance …

Design Optimization And Motion Planning For Pneumatically-Actuated Manipulators, Daniel Mark Bodily

Theses and Dissertations

Soft robotic systems are becoming increasingly popular as they are generally safer, lighter, and easier to manufacture than their more rigid, traditional counterparts. These advantages allow an increased sense of freedom in both the design and operation of these platforms. In this work, we seek methods of leveraging this freedom to both design and plan motions for two different serial-chain, pneumatically actuated manipulators developed by Pneubotics, a small startup company based in San Francisco. In doing so, we focus primarily on two related endeavors: (1) the optimal kinematic design of these and other similar robots (i.e., choosing link lengths, base …

Urban Park Design, Level Of Enclosure And People’S Satisfaction: A Comparative Analysis Of Al Jahili And Al Selimi Parks In Al Ain, Uae, Amnah Ali S Gargoum

Theses

The purpose of this research is to understand how physical characteristics of parks with a particular focus on different levels of enclosure affect park usage level and user patterns in the city of Al-Ain, UAE. Parks in Al Ain are present in different parts of the city and provide plenty of opportunities for leisure and recreation. Despite this diversity, parks located within the inner city area remain the most popular among the residents of Al-Ain, and have expanded significantly in the last few years. Specifically, this thesis aims to understand how the levels of usage and the behavioral patterns of …

Ballistic Limit Equations For Non-Aluminum Projectiles Impacting Dual-Wall Spacecraft Systems, William P. Schonberg, J. Martin Ratliff

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

One of the primary design considerations of earth-orbiting spacecraft is the mitigation of the damage that might occur from an on-orbit MMOD impact. Traditional damage-resistant design consists of a 'bumper' that is placed a small distance away from a spacecraft component or from the wall of the element in which it is housed. The performance of such a multi-wall structural element is typically characterized by its ballistic limit equation (BLE), which defines the threshold particle size that results in a failure of the spacecraft element. BLEs are also key components of any micro-meteoroid/orbital debris (MMOD) risk assessment calculations. However, these …

Studies Of Hypervelocity Impact Phenomena As Applied To The Protection Of Spacecraft Operating In The Mmod Environment, William P. Schonberg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In keeping with the tradition of the Hypervelocity Impact Society, this paper is a written version of the keynote address I presented at the start of 2015 Hypervelocity Impact Symposium as the recipient of the Society's Distinguished Scientist Award. It covers the highlights of my nearly 30 year career working in the area of hypervelocity impact phenomenology, mainly as it is applied to the protection of humans and spacecraft that work an operate in the micrometeoroid and orbital debris (MMOD) environment.

Gradient-Enriched Finite Element Methodology For Axisymmetric Problems, C. Bagni, H. Askes, E. C. Aifantis

Michigan Tech Publications, Part 1

Due to the axisymmetric nature of many engineering problems, bi-dimensional axisymmetric finite elements play an important role in the numerical analysis of structures, as well as advanced technology micro/nano-components and devices (nano-tubes, nano-wires, micro-/nano-pillars, micro-electrodes). In this paper, a straightforward C0-continuous gradient-enriched finite element methodology is proposed for the solution of axisymmetric geometries, including both axisymmetric and non-axisymmetric loads. Considerations about the best integration rules and an exhaustive convergence study are also provided along with guidances on optimal element size. Moreover, by applying the present methodology to cylindrical bars characterised by a circumferential sharp crack, the ability of the present …

Woodchip Denitrification Bioreactor For Reducing Nitrate In Contaminated Well Water For St. Francis Retreat Center, Andrew Highlander, Patrick Johnson

Civil, Environmental and Sustainable Engineering Senior Theses

The St. Francis Retreat Center, which serves over 7000 people each year, has had issues with the health of Flint Lake, located on their property, during the drought season. By utilizing a nearby water well, the retreat center looks to recharge the lake and sustain its water levels, essentially restoring its natural ecosystem. The issue is that the well water is contaminated with high amounts of nitrates, which is not only an issue for the lake’s health, but also is very unsafe for human consumption. In order to design a water treatment system that is ecofriendly, sustainable, and cost-efficient, the …

Decentralized Wastewater Treatment Plant In Bangalore, India, Cameron Akhavan, Simon Barbe, Alejandro Fernandez Fernandez

Civil, Environmental and Sustainable Engineering Senior Theses

The Vrishabawathi River in Bangalore, India, has high levels of pollution due to untreated wastewater discharges from the city. The city requires significant expansion of its wastewater treatment infrastructure. Smaller-capacity plants spread throughout the city, known as decentralized treatment plants, provide an alternative to centralized treatment plants that can meet these demands. This project involved the design of one decentralized plant. This plant is located in the Kengeri district of the city, a mostly residential area in the outskirts of Bangalore. The designed treatment facility includes two primary clarifiers, two biotowers, and two secondary clarifiers. Plants like these can help …

Behavior And Strength Of Rc Spandrel Members Under Unsymmetrical Bending And Torsion Including Cfrp Retrofitting, Muhammad Fahim

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of an experimental and theoretical investigation of the behavior and strength of reinforced concrete spandrel members both with and without carbon fiber reinforced polymer (CFRP) retrofitting. Both isolated spandrel members with L-shaped cross section as well as those integrated with reinforced concrete slabs are studied. A series of isolated spandrel members were tested under separate and combined actions of unsymmetrical bending and torsion. Six of these specimens were retrofitted externally with high-strength CFRP strips. Materially nonlinear analysis procedures are also formulated and programmed for the spandrel members with and without CFRP retrofitting. Furthermore, ultimate bending-torsion …

Development Of An Analysis And Design Optimization Framework For Marine Propellers, Ashish C. Tamhane

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, a framework for the analysis and design optimization of ship propellers is developed. This framework can be utilized as an efficient synthesis tool in order to determine the main geometric characteristics of the propeller but also to provide the designer with the capability to optimize the shape of the blade sections based on their specific criteria.

A hybrid lifting-line method with lifting-surface corrections to account for the three-dimensional flow effects has been developed. The prediction of the correction factors is achieved using Artificial Neural Networks and Support Vector Regression. This approach results in increased approximation accuracy compared …

Behavior And Strength Of Non-Prestressed And Prestressed Hillman Composite Beam Including Cfrp Retrofitting, Wajid Khan

Civil & Environmental Engineering Theses & Dissertations

The Hillman Composite Beam (HCB) is a recent innovation used for the first time in 2008 for a bridge construction in USA. It essentially consists of an FRP outer shell, concrete arch inside the shell and steel strands used to tie the two ends of the arch. Being new in the field, the behavior of HCB has not been thoroughly studied. This dissertation presents a study of the flexural behavior and strength of HCB up to the collapse as well as explores the influence of using carbon reinforced polymer (CFRP) retrofitting and prestressed steel for a further increase in HCB …

Deposition Of Silicon Thin Films By Ion Beam Assisted Deposition, Tejaswini Miryala

Electrical & Computer Engineering Theses & Dissertations

With the depletion of non-renewable energy sources owing to increasing demands, we need to develop renewable energy sources, which can replace them with cleaner energy sources. The solar industry is one of these renewable energies. In spite of having very high potential, harvesting solar energy has been a challenge due to the cost of solar cells. Silicon dominates the photovoltaic industry, but even this technology can accommodate great improvements. This can be done notably by finding low cost deposition techniques for the silicon. The main aim of this thesis is to form high-quality nanocrystalline silicon thin films with the help …

Analysis Of Project Management System Structure Using The Viable System Model (Vsm), Joseph A. Sisti

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this research was to explore the applicability of the Viable System Model as a framework for structural analysis of Project Management Systems using a case study approach. The research used a modified Viable System Model based on the work of Stafford Beer (1979) for the analysis of systems (organizations). The specific research questions explored in this research were: (1) How can the Viable System Model (VSM) be adapted for analysis of project management structure? And, (2) What results from exploration of the Viable System Model framework application to active project management structures?

The research used an exploratory …

Impact Of A Localized Lean Six Sigma Implementation On Overall Patient Safety And Process Efficiency, Luvianca G. Gil-Moreno

Engineering Management & Systems Engineering Theses & Dissertations

Continuous quality improvement tools have been widely used in the Healthcare Industry to increase efficiency and patient safety as well as to reduce cost. This research explores the impact of a Lean Six Sigma (LSS) process improvement initiative on the overall process efficiency and patient safety in the Labor and Delivery (L+D) units of a large hospital provider. This study focuses on the application of a modeling and simulation methodology to investigate the influence of a localized process improvement intervention on the overall L+D unit output by considering patient flow, system capacity, and unit performance. The simulation models capacity profiles …

Role Of Requirements Engineering In Software Project’S Success, Sujatha Alla

Engineering Management & Systems Engineering Theses & Dissertations

Despite considerable time and resources spent on the initiation phase of software projects, discrepancies often exist between formal project documentation, customer requirements, and final project specifications. Such discrepancies in the requirements management process can have a very negative impact on final project outcomes. A Business Requirements Document (BRD) constitutes the formal software requirements documentation, which typically includes stakeholders’ needs and expectations and project scope while providing a clear project roadmap and project plan. According to IEEE standards, a BRD should be a structured document that includes specific elements such as functional and technical requirements while incorporating certain traits such as …

Optimal Ship Maintenance Scheduling Under Restricted Conditions And Constrained Resources, Vi Hong Nguyen

Mechanical & Aerospace Engineering Theses & Dissertations

The research presented in this dissertation addresses the application of evolution algorithms, i.e. Genetic Algorithm (GA) and Differential Evolution algorithm (DE) to scheduling problems in the presence of restricted conditions and resource limitations. This research is motivated by the scheduling of engineering design tasks in shop scheduling problems and ship maintenance scheduling problems to minimize total completion time. The thesis consists of two major parts; the first corresponds to the first appended paper and deals with the computational complexity of mixed shop scheduling problems. A modified Genetic algorithm is proposed to solve the problem. Computational experiments, conducted to evaluate its …

A Predictor Analysis Framework For Surface Radiation Budget Reprocessing Using Design Of Experiments, Patricia Allison Quigley

Engineering Management & Systems Engineering Theses & Dissertations

Earth’s Radiation Budget (ERB) is an accounting of all incoming energy from the sun and outgoing energy reflected and radiated to space by earth’s surface and atmosphere. The National Aeronautics and Space Administration (NASA)/Global Energy and Water Cycle Experiment (GEWEX) Surface Radiation Budget (SRB) project produces and archives long-term datasets representative of this energy exchange system on a global scale. The data are comprised of the longwave and shortwave radiative components of the system and is algorithmically derived from satellite and atmospheric assimilation products, and acquired atmospheric data. It is stored as 3-hourly, daily, monthly/3-hourly, and monthly averages of 1°x1° …

Quantifying Cyanide Inhibition Of Nitrification And Developing Cost-Effective Treatment Processes, Germano M. Salazar-Benites

Civil & Environmental Engineering Theses & Dissertations

All wastewater treatment plants that operate multiple hearth furnaces (MHF) and are required to nitrify must manage the inhibitory effects of free cyanide (HCN, CN-) in the scrubber return flows due to inhibitory impacts on nitrifying bacteria.

HRSD Boat Harbor Treatment Plant (BHTP) a 25 MGD facility consisting of primary and secondary treatment, employs an anoxic selector process for nitrification and partial denitrification and operates a MHF. There is a desire to improve TN removal performance at BHTP due to an annual mass-based bubble permit limit on a combined discharge from seven HRSD plants, and there are no discharge limitations …

Multi-Mode Resource Constrained Project Scheduling Using Differential Evolution Algorithm, Faisal Manour Altarazi

Mechanical & Aerospace Engineering Theses & Dissertations

Project scheduling is a tool that manages the work and resources associated with delivering a project on time. Project scheduling is important to organize, keep track of the finished and in-progress tasks and manage the quality of work delivered. However, many problems arise during project scheduling. Minimizing project duration is the primary objective. Project cost is also a critical matter, but there will always be a trade off between project time and cost (Ghoddousiet et al., 2013), so scheduling activities can be challenging due to precedence activities, resources, and execution modes. Schedule reduction is heavily dependent on the availability of …

An Investigation Into The Potential Benefits Of Distributed Electric Propulsion On Small Uavs At Low Reynolds Numbers, Engin Baris

Mechanical & Aerospace Engineering Theses & Dissertations

Distributed electric propulsion systems benefit from the inherent scale independence of electric propulsion. This property allows the designer to place multiple small electric motors along the wing of an aircraft instead of using a single or several internal combustion motors with gear boxes or other power train components. Aircraft operating at low Reynolds numbers are ideal candidates for benefiting from increased local flow velocities as provided by distributed propulsion systems.

In this study, a distributed electric propulsion system made up of eight motor/propellers was integrated into the leading edge of a small fixed wing-body model to investigate the expected improvements …

Study Of A High-Efficient Wide-Bandgap Dc-Dc Power Converter For Solar Power Integration, Yashwanth Bezawada

Electrical & Computer Engineering Theses & Dissertations

This research focuses on the design and analysis of a Boost cascaded Buck-Boost (BoCBB) power converter with super high efficiency in electric power conversion. The BoCBB power converter is based on emerging wide-bandgap silicon-carbide (SiC) MOSFETs and Schottky diodes, which have only 1/6 times of power loss in traditional silicon power semiconductor devices. The BoCBB power converter can be widely applied in solar harvesting for the National Aeronautics and Space Administration (NASA), military bases and electric utilities, as well as high-power DC motor drives for the electric vehicles, robotics, and manufacturing and product lines.

This research analyzed the topology and …

Recurrent Neural Networks And Matrix Methods For Cognitive Radio Spectrum Prediction And Security, Alexander M. Glandon

Electrical & Computer Engineering Theses & Dissertations

In this work, machine learning tools, including recurrent neural networks (RNNs), matrix completion, and non-negative matrix factorization (NMF), are used for cognitive radio problems. Specifically addressed are a missing data problem and a blind signal separation problem. A specialized RNN called Cellular Simultaneous Recurrent Network (CSRN), typically used in image processing applications, has been modified. The CRSN performs well for spatial spectrum prediction of radio signals with missing data. An algorithm called soft-impute for matrix completion used together with an RNN performs well for missing data problems in the radio spectrum time-frequency domain. Estimating missing spectrum data can improve cognitive …

Hydrologic Response Caused By Wetland Expansion At Huntley Meadows Park In Hybla Valley, Virginia, Stephen Fraser Stone

OES Theses and Dissertations

The goal of this study was to understand the effects of wetland expansion across a watershed. The 2013 restoration and expansion of the wetlands at Huntley Meadows Park (Fairfax County, VA) performed by Wetland Studies and Solutions, Inc. provided the opportunity to study this process. The 630 ha park contains more than 364 ha of freshwater emergent and freshwater forested wetlands. The restoration and expansion project used a subsurface vinyl-piling dam that impedes groundwater flow leaving the wetland, thus expanding the existing pond and the surrounding wetland.

This study used a network of more than twenty monitoring instruments making observations …

A Study Of The Sensitivity Of Energy Conversion Efficiency To Load Variation In Class-E Resonant Power Inverter, Richard Samuel Jennings

Electrical & Computer Engineering Theses & Dissertations

In this thesis the sensitivity of energy conversion efficiency (ECE) and output power of a class-E resonant inverter under variable resistive and inductive load assignments is examined for wireless power transfer (WPT) applications. By performing simulation and mathematical analysis, it was found that the on-resistance of the switching device has minor effect on the design’s efficiency. Additional comparisons between the simulation and mathematical analysis show reasonable output power and ECE load variation performance for the design, but with unique load impedances where zero voltage switching (ZVS) and zero derivative switching (ZDS) are achieved. These comparisons also expose inaccurate mathematical assumptions. …

Investigation Of Low Cost Substrate Approaches For Iii-V Solar Cells, Marlene Lydia Lichty

Electrical & Computer Engineering Theses & Dissertations

With the need for cleaner energy sources, which can displace fossil fuel, the solar cell industry is of particular interest due to the abundancy of the Sun. Silicon currently dominates terrestrial applications, but efficiency improvements have saturated. III-V based solar cells have reported the highest efficiencies, however, high costs due to substrates and fabrication processes have limited these devices to specialty applications, such as space. In order to reduce the cost associated with fabricating III-V semiconductor substrate material, two different approaches were taken in this work with a particular focus on making III-Vs more applicable outside of specialty applications, including …

Modification Of Deposition Process Parameters For Uniform Indium Layer Deposition, Isaac Butt

Electrical & Computer Engineering Theses & Dissertations

The need for more efficient light to energy converting cells has long been a subject of research and development. With abundant availability of solar energy that the earth receives, the photovoltaic industry has sought materials that could serve the purpose of great energy conversion. The photovoltaic industry is mainly dominated by Silicon owing to its abundant availability, reliability and economic cost. However, due to limitations on efficiency improvements, some focus has shifted toward III-V based solar cells with a great potential for attaining higher efficiency and multi-junction applications. However, the cost of the III-V materials is extremely high due to …

A Household Daily Non-Mandatory Activity Participation And Duration Modeling Accounting For Person Level Budget Constraints, Ivana Vukovic

Civil & Environmental Engineering Theses & Dissertations

A key methodological and behavioral innovative component in recent Activity-Based Models (ABMs) used for transportation planning is the household-level non-mandatory activity participation component. While traditional ABMs use a series of simple models to predict non-mandatory activity participation decisions in a sequential manner (which is often not correct), the Multiple Discrete Continuous Extreme Value (MDCEV) model can model both individual and joint non-mandatory activity participation and time allocation decisions in different out-of-home activities of all household members simultaneously. A key advantage of the MDCEV framework is that it accounts for complex intra-household interactions among different household members by allocating the total …

Low Temperature Plasma For The Treatment Of Epithelial Cancer Cells, Soheila Mohades

Electrical & Computer Engineering Theses & Dissertations

Biomedical applications of low temperature plasmas (LTP) may lead to a paradigm shift in treating various diseases by conducting fundamental research on the effects of LTP on cells, tissues, organisms (plants, insects, and microorganisms). This is a rapidly growing interdisciplinary research field that involves engineering, physics, life sciences, and chemistry to find novel solutions for urgent medical needs. Effects of different LTP sources have shown the anti-tumor properties of plasma exposure; however, there are still many unknowns about the interaction of plasma with eukaryotic cells which must be elucidated in order to evaluate the practical potential of plasma in cancer …