Engineering Commons^™

Galvanic Corrosion Of Magnesium Coupled To Steel At High Cathode-To-Anode Area Ratios, Dila Ram Banjade

Theses and Dissertations

In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, the role of self-corrosion was quantified as previous studies showed discrepancies between model predictions and experimental results that were likely due to significant self-corrosion. This experimental study examined the corrosion of Mg coupled to steel in 5 wt% NaCl at cathode-to-anode area ratios that ranged from 5 to 27. Results showed that self-corrosion was significant and accounted for, on average, one-third of total corrosion. Moreover, self-corrosion varied with time and cathode size, and was …

Enhanced-Resolution Processing And Applications Of The Ascat Scatterometer, Richard D. Lindsley

Theses and Dissertations

The ASCAT scatterometer measures the Earth surface microwave radar backscatter in order to estimate the near-surface winds over the oceans. While the spatial resolution of the conventional applications is sufficient for many purposes, other geoscience applications benefit from an improved spatial resolution. Specialized algorithms may be applied to the scatterometer data in order to reconstruct the radar backscatter on a high-resolution grid. Image reconstruction requires the spatial response function (SRF) of each measurement, which is not reported with the measurement data. To address this need, I precisely model the SRF incorporating (1) the antenna beam response, (2) the processing performed …

Stochastic Simulation Of Lagrangian Particle Transport In Turbulent Flows, Guangyuan Sun

Theses and Dissertations

This dissertation presents the development and validation of the One Dimensional Turbulence (ODT) multiphase model in the Lagrangian reference frame. ODT is a stochastic model that captures the full range of length and time scales and provides statistical information on fine-scale turbulent-particle mixing and transport at low computational cost. The flow evolution is governed by a deterministic solution of the viscous processes and a stochastic representation of advection through stochastic domain mapping processes. The three algorithms for Lagrangian particle transport are presented within the context of the ODT approach. The Type-I and -C models consider the particle-eddy interaction as instantaneous …

Adaptive Scaling Of Cluster Boundaries For Large-Scale Social Media Data Clustering, Lei Meng, Ah-Hwee Tan, Donald C. Wunsch

Research Collection School Of Computing and Information Systems

The large scale and complex nature of social media data raises the need to scale clustering techniques to big data and make them capable of automatically identifying data clusters with few empirical settings. In this paper, we present our investigation and three algorithms based on the fuzzy adaptive resonance theory (Fuzzy ART) that have linear computational complexity, use a single parameter, i.e., the vigilance parameter to identify data clusters, and are robust to modest parameter settings. The contribution of this paper lies in two aspects. First, we theoretically demonstrate how complement coding, commonly known as a normalization method, changes the …

Bep: Bit Error Pattern Measurement And Analysis In Ieee 802.11, Jiayue Li, Zimu Zhou, Chen Zhang, Liang Yin, Lionel M. Ni

Research Collection School Of Computing and Information Systems

The IEEE 802.11 is a set of Media Access Control (MAC) and Physical Layer (PHY) specifications which concern the Wireless Local Area Network (WLAN) service. However, most IEEE 802.11 WLAN services are easily affected by external elements, such as the homogeneous interference caused by the high-density deployment of IEEE 802.11 devices, the attenuation effect caused by complicated indoor obstacles, and the heterogeneous interference caused by other devices which operate out of unlicensed 2.4GHz ISM bands. In this paper, we first present a method to capture IEEE 802.11n Bit Error Patterns (BEP) under the network effect such as the homogeneous interference …

Effect Of Ni On The Formability And Texture Of Hot Rolled Weathering Steel, Gadadhar Sahoo, I. S. Wani, S. B. Kumar, Balbir Singh, Atul Saxena, R. Basu

Journal of Metals, Materials and Minerals

Formability behavior in two grades of hot rolled low carbon weathering steel with varying nickel content i.e., SCR 1 (Fe-0.116P-0.018Ni) and SCR 2 (Fe-0.115P-0.34Ni), have been evaluated in relationship to microstructure, EBSD estimated orientation distribution function (ODF), special boundary nature, mechanical properties and formability parameters like tensile stain hardening exponent (n) and plastic anisotropy ratio (r). The alloy sample SCR 1 exhibited improved formability characteristics in terms of stain hardening exponent (n) and plastic anisotropy ratio (r). This was mainly attributed to relatively higher fraction of the ND//<111> orientation or the ? fibre texture component and increased presence of sigma …

Processing Of Nano Fillers In Nitrile Rubber A Novel Technique, Abitha V. K., Ajay Vasudeo Rane, K. Rajkumar

Journal of Metals, Materials and Minerals

Dispersion of various nano fillers like Nano silica, nano clay, Nano TiO2, etc has been attempted in NBR rubbers using new technique of dispersion. Liquid NBR is taken as dispersion media for nano fillers in polymer matrix and polymer nano composites were characterized by Rubber Process Analyzer [RPA-2000, USA]. The dispersion of the nano fillers were investigated by XRD, SEM-EDS. The effect of increasing nano- fillers on mechanical properties like tensile strength, modulus and Elongation at break was studied. Hot air ageing of polymer nano composites was also studied.Dispersion of various nano fillers like Nano silica, nano clay, Nano TiO2, …

Microstructure Based Finite Element Simulation Of Jco Forming Process For Pipeline X65, Wut Thianngoen, Saranya Kingklang, Vitoon Uthaisangsuk

Journal of Metals, Materials and Minerals

In recent years, strong increases in energy demand have become the most important issue in every section. High strength pipeline steels make large contribution to cost reduction for fuel transportation in oil and gas industries due to their great combination of optimal strength and toughness properties. Mechanical properties of pipeline steel tubes are significantly influenced by their microstructure characteristics, which in turn are controlled by the production. In this work, the JCO forming process of gas pipeline tube made of hotrolled steel grade X65 with ferrite/pearlite microstructure was investigated by means of a FE multiscale modeling approach. Three different scales …

Sound Attenuation Of Fiberglass Lined Ventilation Ducts, Jacob Albright

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sound attenuation is a crucial part of designing any HVAC system. Most ventilation systems are designed to be in areas occupied by one or more persons. If these systems do not adequately attenuate the sound of the supply fan, compressor, or any other source of sound, the affected area could be subject to an array of problems ranging from an annoying hum to a deafening howl. The goals of this project are to quantify the sound attenuation properties of fiberglass duct liner and to perform a regression analysis to develop equations to predict insertion loss values for both rectangular and …

A Lidar Based Semi-Autonomous Collision Avoidance System And The Development Of A Hardware-In-The-Loop Simulator To Aid In Algorithm Development And Human Studies, Thomas F. Stevens

Master's Theses

In this paper, the architecture and implementation of an embedded controller for a steering based semi-autonomous collision avoidance system on a 1/10^th scale model is presented. In addition, the development of a 2D hardware-in-the-loop simulator with vehicle dynamics based on the bicycle model is described. The semi-autonomous collision avoidance software is fully contained onboard a single-board computer running embedded GNU/Linux. To eliminate any wired tethers that limit the system’s abilities, the driver operates the vehicle at a user-control-station through a wireless Bluetooth interface. The user-control-station is outfitted with a game-controller that provides standard steering wheel and pedal controls along …

Open Source Toolkit For Reentry Object Modeling, Christopher Lloyd Ostrom Ii

Master's Theses

Predicting the mass, position, and velocity of an object during its reentry are critical to satisfy NASA and ESA requirements. This thesis outlines a 3-D orbit and mass determination system for use on low earth orbit as applicable to general objects, of various material and size. The solution uses analytical models to calculate heat flux and aerodynamic drag, with some basic numerical models for simple orbit propagation and mass flow rate due to ablation. The system outlined in this thesis currently provides a framework for rough estimates of demise altitude and final mass, but also allows for many potential accuracy …

Divergent Plume Reduction Of A High-Efficiency Multistage Plasma Thruster, Christopher M. Barlog

Master's Theses

High Efficiency Multistage Plasma Thrusters (HEMPTs) are a relatively new form of electric propulsion that show promise for use on a variety of missions and have several advantages over their older EP competitors. One such advantage is their long predicted lifetime and minimal wall erosion due to a unique periodic permanent magnet system. A laboratory HEMPT was built and donated by JPL for testing at Cal Poly. Previous work was done to characterize the performance of this thruster and it was found to exhibit a large plume divergence, resulting in decreased thrust and specific impulse. This thesis explores the design …

Three Degree-Of-Freedom Parallel Actuator Telescope Mount, Garrett Daniel Gudgel

Master's Theses

This thesis contains the design, implementation, and testing of an original, small-scaled two degree-of-freedom telescope mount and a medium-scaled three degree-of-freedom telescope mount inspired by the six degree-of-freedom Stewart-Gough platform telescope mount. The end product is intended to achieve research-standard resolution of targeted sky coverage for binary star research. The scaled prototype was carried through concept design, manufacturing, software development, and testing. The mount software development and electronic design is applicable to a full-scale mount as the drivers have been designed to be easily adapted to different actuator configurations. It is recommended that this design be implemented into a telescope …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Scaled Synthetic Aperture Radar System Development, Ryan K. Green

Master's Theses

Synthetic Aperture Radar (SAR) systems generate two dimensional images of a target area using RF energy as opposed to light waves used by cameras. When cloud cover or other optical obstructions prevent camera imaging over a target area, SAR can be substituted to generate high resolution images. Linear frequency modulated signals are transmitted and received while a moving imaging platform traverses a target area to develop high resolution images through modern digital signal processing (DSP) techniques. The motivation for this joint thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Objectives include …

Structural Damage Assessment Using Artificial Neural Networks And Artificial Immune Systems, Arthur Q.X. Shi

Master's Theses

Structural health monitoring (SHM) systems have been technologically advancing over the past few years. Improvements in fabrication and microelectronics allow the development of highly sophisticated sensor arrays, capable of detecting and transmitting an unprecedented amount of data. As the complexity of the hardware increases, research has been performed in developing the means to best utilize and effectively process the data. Algorithms from other computational fields are being introduced for the first time into SHM systems. Among them, the artificial neural network (ANN) and artificial immune systems (AIS) show great potential. In this thesis, features are extracted out of the acceleration …

Automated Multi-Modal Search And Rescue Using Boosted Histogram Of Oriented Gradients, Matthew A. Lienemann

Master's Theses

Unmanned Aerial Vehicles (UAVs) provides a platform for many automated tasks and with an ever increasing advances in computing, these tasks can be more complex. The use of UAVs is expanded in this thesis with the goal of Search and Rescue (SAR), where a UAV can assist fast responders to search for a lost person and relay possible search areas back to SAR teams. To identify a person from an aerial perspective, low-level Histogram of Oriented Gradients (HOG) feature descriptors are used over a segmented region, provided from thermal data, to increase classification speed. This thesis also introduces a dataset …

Spacecraft Trajectory Optimization Suite (Stops): Optimization Of Multiple Gravity Assist Spacecraft Trajectories Using Modern Optimization Techniques, Timothy J. Fitzgerald

Master's Theses

In trajectory optimization, a common objective is to minimize propellant mass via multiple gravity assist maneuvers (MGAs). Some computer programs have been developed to analyze MGA trajectories. One of these programs, Parallel Global Multiobjective Optimization (PaGMO), uses an interesting technique known as the Island Model Paradigm. This work provides the community with a MATLAB optimizer, STOpS, that utilizes this same Island Model Paradigm with five different optimization algorithms. STOpS allows optimization of a weighted combination of many parameters. This work contains a study on optimization algorithm performance and how each algorithm is affected by its available settings.

STOpS successfully found …

Sparse Aperture Speckle Interferometry Telescope Active Optics Control System, Matthew Clause

Master's Theses

A conventional large aperture telescope required for binary star research is typically cost prohibitive. A prototype active optics system was created and fitted to a telescope frame using relatively low cost components. The active optics system was capable of tipping, tilting, and elevating the mirrors to align reflected star light. The low cost mirror position actuators have a resolution of 31 nm, repeatable to within 16 nm. This is accurate enough to perform speckle analysis for the visible light spectrum. The mirrors used in testing were not supported with a whiffletree and produced trefoil-like aberrations which made phasing two mirrors …

Ergonomics Analysis Of Touchscreen Utilization As A Function Of Preferred Hand And Gender, Jordan E. Odell

Master's Theses

The growth of touchscreen technology has changed the way users interface with a wide range of computing and communication products and systems. Examples range from personal tablets and laptops to industrial applications such as process control, point-of-sales, and ticketing kiosk systems. An important area of application is the automobile industry which is designing cars with touchscreen control panels to replace the previously designed mechanical knobs and buttons. However, interacting with touchscreens does not provide the same tactile feedback as physical mechanisms, therefore they require more precise movement and visual attention, which distracts the user from the primary task.

The purpose …

Cost-Based Decision Making Model For Regional In-House Versus Outsourcing Logistics, Henrik Darren Lee

Master's Theses

This thesis proposes a model for selecting between insourcing logistics for local distribution and outsourcing these functions to a third-party logistics (3PL) company. Supply chain optimization, as well as global supply chain management, are topics that are now well-covered; local distribution, despite its integral function in an organization, is much less researched. Models exist for network design and optimization, but the practical application of these network models may call for decisions and considerations that are not covered in these optimization models.

A breakeven analysis selection model between using in-house logistic system and 3PL is derived, considering various regional parameters. The …

Identifying And Predicting Rat Behavior Using Neural Networks, Jonathan A. Gettner

Master's Theses

The hippocampus is known to play a critical role in episodic memory function. Understanding the relation between electrophysiological activity in a rat hippocampus and rat behavior may be helpful in studying pathological diseases that corrupt electrical signaling in the hippocampus, such as Parkinson’s and Alzheimer’s. Additionally, having a method to interpret rat behaviors from neural activity may help in understanding the dynamics of rat neural activity that are associated with certain identified behaviors.

In this thesis, neural networks are used as a black-box model to map electrophysiological data, representative of an ensemble of neurons in the hippocampus, to a T-maze, …

Inductive Monitoring Systems: A Cubesat Ground-Based Prototype, Michelle Haddock

Master's Theses

Inductive Monitoring Systems (IMS) are the newest form of health monitoring available to the aerospace industry. IMS is a program that builds a knowledge base of nominal state vectors from a nominal data set using data mining techniques. The nominal knowledge base is then used to monitor new data vectors for off-nominal conditions within the system. IMS is designed to replace the current health monitoring process, referred to as model-based reasoning, by automating the process of classifying healthy states and anomaly detection. An IMS prototype was designed and implemented in MATLAB. A verification analysis then determined if the IMS program …

Two-Phase Anaerobic Digestion To Reduce The Nox Emission Potential Of Biogas, Nathaniel Manuel Olivas

Master's Theses

Anaerobic digestion can be used to decrease the mass of organic wastes to be disposed of while producing useful biogas (CH₄ and CO₂) for heat or power production, but in air basins with strict emissions limits, biogas combustion is difficult to implement due to the high costs of controlling NOx emissions. NOx production can be minimized by blending H₂ gas with CH₄ at a volume ratio of 15:85 H₂:CH₄, which allows burning at ultra-lean air-to-fuel ratios. For biogas systems, a potential low-cost NOx control strategy is to produce H₂-CH …

Process Development For Compression Molding Of Hybrid Continuous And Chopped Carbon Fiber Prepreg For Production Of Functionally Graded Composite Structures, Corinne Marie Warnock

Master's Theses

Composite materials offer a high strength-to-weight ratio and directional load bearing capabilities. Compression molding of composite materials yields a superior surface finish and good dimensional stability between component lots with faster processing compared to traditional manufacturing methods. This experimental compression molding capability was developed for the ME composites lab using unidirectional carbon fiber prepreg composites. A direct comparison was drawn between autoclave and compression molding methods to validate compression molding as an alternative manufacturing method in that lab. A method of manufacturing chopped fiber from existing unidirectional prepreg materials was developed and evaluated using destructive testing methods. The results from …

Dual-Input Dc-To-Dc Converter Topologies And Control Schemes, Shaun Alan Stickel

Boise State University Theses and Dissertations

Dual-input DC-to-DC converters are power supplies that draw power from two sources simultaneously and deliver power to a single load, the ratio of power drawn from each source and be held constant with changes in the load. Applications for dual-input power supplies are computer systems, mobile systems using energy harvesting, and systems needing redundant power supplies. This writing covers the operation and control of dual-input DC-to-DC converters that implement a non-inverting buck-boost function and utilize only a single power path.

Traditionally, a dual-input power supply is created by placing two standard power paths in parallel. This adds considerable control complexity …

A Small Acoustic Goniometer For General Purpose Research, Michael Pook

Boise State University Theses and Dissertations

Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of the acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this research. This dissertation focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in …

An Integrated Framework For Fostering Human Factor Sustainability And Increased Safety In Aviation Ramp Operations, Sarah M. Hubbard, Denver Lopp

Journal of Aviation Technology and Engineering

The aviation work environment has one of the highest accident rates of any industry sector in the United States, resulting in significant costs for both employee injuries and equipment damage. In fact, injury rates exceed rates found in areas that are widely recognized as hazardous, such as construction and mining, and it is estimated that aircraft ground damage costs are as high as 5 billion to 10 billion dollars per year. Purdue University’s Aviation Technology Department has conducted numerous safety and human factors studies in the past decade encompassing maintenance and repair operations, corporate flight departments, and over ten major …

Tailwinds Can Reduce Groundspeed Too, Nihad E. Daidzic

Aviation Department Publications

FAA Safety Seminar (GL1565666) held at Minnesota State University, Mankato Ostranger Auditorium at 18:30 CST on Monday, November 30, 2015.

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

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