Engineering Commons^™

Air Charge Estimation For An Si Engine Using In-Cylinder Pressure Sensor, Arya Yazdani

Dissertations, Master's Theses and Master's Reports

An accurate estimation of cycle by cycle in-cylinder mass and the composition of the combustion chamber charge is required for engine control strategies to meet stringent pollution emission and fuel consumption regulations. Estimation of fresh charge and residual gas masses is beneficial in terms of fuel efficiency, tailpipe emissions, engine performance, for engine control strategies. Air-flow meter, which is mounted in the intake air circuit, can be utilized in a closed-loop strategy to control air charge. However, air flow meter has a response delay; moreover dynamics of intake manifold and pipes must be taken into consideration to improve the estimation …

Nanosphere Lithography And Its Application In Rapid And Economic Fabrication Of Plasmonic Hydrogenated Amorphous Silicon Photovoltaic Devices, Chenlong Zhang

Dissertations, Master's Theses and Master's Reports

Solar photovoltaic (PV) devices harvest energy from solar radiation and convert it to electricity. PV technologies, as an alternative to traditional fossil fuels, use clean and renewable energy while minimizing pollution. For decades researchers have been developing thin film solar cells as an important alternatives to the relatively expensive bulk crystal solar cell technology. Among those, hydrogenated amorphous silicon (a-Si:H) solar cells prevails for good efficiency, non-toxic and materially abundant nature. However, a-Si:H thickness must be minimized to prevent light induced degradation, so optical enhancement is necessary. Light manipulation has to be applied and carefully engineered to trap light within …

Designing A Permeable Reactive Barrier For The Remediation Of Copper Contaminated Groundwater., Christopher Walkons

Dissertations, Master's Theses and Master's Reports

This project details the design of a sorption based pilot-scale permeable reactive barrier (PRB) for the removal of copper from groundwater. The reactive material for the barrier is the residual of coagulants used in drinking water treatment operations. Physical and chemical properties of these water treatment residuals (WTR) have been studied to optimize PRB design. Batch reactor tests have shown that equilibrium sorption of copper can be fit to a Langmuir type isotherm. Kinetic and column experiments have been conducted to understand the significance of chemical and physical mass transfer limitations. A leaching test indicated the concentrations of hazardous elements …

Enhancing Osseointegration Of Orthopaedic Implants With Titania Nanotube Surfaces, Erin A. Baker

Dissertations, Master's Theses and Master's Reports

Introduction: As joint arthroplasty surgical procedures increase annually, the development of new strategies, including novel materials and surface modifications, to attain solid bone-implant fixation are needed to increase implant terms of service. In this study, we evaluate two morphologies of titania nanotubes in both in vitro and in vivo experiments to quantify osseointegrative potential and material-level biocompatibility.

Materials and Methods: Samples were prepared via an electrochemical etching process. Two different titania nanotube (TiNT) morphologies were produced, Aligned and Trabecular. For the in vitro experiment, Sprague Dawley (SD) rat marrow-derived bone marrow cells (BMC) were seeded on samples. Alkaline phosphatase (ALP) …

A Sustainability-Based Project Selection Algorithm: Socio-Technical-Economic Project Selection (Steps) Algorithm, Bharathi Bhattu

Dissertations, Master's Theses and Master's Reports

Multi-dimensional aspects play a vital role in the task of project-decision making. Environmental effects are to be considered in addition to other technical and non-technical aspects in order to avoid undue environmental damage. This current work introduces a new decision-making algorithm (Socio-Technical-Economic Project Selection or STEPS) that is demonstrated with the use of RCA (recycled concrete aggregate) as riprap for slope stabilization and erosion control which leaches chemical arsenic when in contact with water. Arsenic has long been recognized for its lethal properties. The main intention of introducing this new algorithm is to use sustainability concepts of social, technical, and …

An Experimental Investigation Of The Effect Of Temperature And Space Velocity On The Performance Of A Cu-Zeolite Flow-Through Scr And A Scr Catalyst On A Dpf With And Without Pm Loading, Vaibhav Kadam

Dissertations, Master's Theses and Master's Reports

Abstract The heavy-duty diesel (HDD) engines use the diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and urea injection based selective catalytic reduction (SCR) systems in sequential combination, to meet the US EPA 2010 PM and NOₓ emission standards. The SCR along with a NH₃ slip control catalyst (AMOX) offer NOₓ reduction >90 % with NH₃ slipHowever, there is a strong desire to further improve the NOₓ reduction performance of such systems, to meet the California Optional Low NOₓ Standard implemented since 2015. Integrating SCR functionality into a diesel particulate filter (DPF), by coating the SCR catalyst on the DPF, …

Methodology For Analyzing Epoxy-Cnt Phononic Crystals For Wave Attenuation And Guiding, Madhu Kolati

Dissertations, Master's Theses and Master's Reports

Phononic crystals (PhnCs) control, direct and manipulate sound waves to achieve wave guiding and attenuation. This dissertation presents methodology for analyzing nanotube materials based phononic crystals to achieve control over sound, vibration and stress mitigation. Much of the analytical work presented is in identifying frequency band gaps in which sound or vibration cannot propagate through these PhnCs. Wave attenuation and mitigation analysis is demonstrated using finite element simulation. Engineering principles from current research areas of solid mechanics, solid-state physics, elasto-dynamics, mechanical vibrations and acoustics are employed for the methodology. A considerable effort is put to show that these PhnCs can …

Modeling Impacts Of Combined Sewer Overflows In Swmm In Cleveland, Ohio, Zoe A. Miller

Dissertations, Master's Theses and Master's Reports

Despite its legacy of pollution, the City of Cleveland, Ohio, has historically been at the forefront of water quality management. Today, the Northeast Ohio Regional Sewer District (NEORSD), which serves the Greater Cleveland area, is following a consent decree with the State of Ohio to minimize combined sewer overflows (CSOs), along with implementing an integrated Clean Water Act planning study to prioritize infrastructure improvements with a broader view of water quality objectives. This report summarizes an urban watershed modeling effort to support the integrated planning (IP) process. Specifically, the development, calibration, and validation of the EPA Stormwater Management Model (SWMM) …

Representation And Analysis Of Multi-Modal, Nonuniform Time Series Data: An Application To Survival Prognosis Of Oncology Patients In An Outpatient Setting, Jennifer Winikus

Dissertations, Master's Theses and Master's Reports

The representation of nonuniform, multi-modal, time-limited time series data is complex and explored through the use of discrete representation, dimensionality reduction with segmentation based techniques, and with behavioral representation approaches. These explorations are done with a focus on an outpatient oncology setting with the classification and regression analysis being used for length of survival prognosis. Each decision of representation and analysis is not independent, with implications of each decision in method for how the data is represented and then which analysis technique is used. One unique aspect of the work is the use of outpatient clinical data for patients, which …

Acoustic Behavior Of Soil Reinforced With Grass Roots, Blake Armstrong

Electronic Theses and Dissertations

Civil engineering practice has shown that vegetative roots on slopes and streambanks can substantially increase shear strength of soil and reduce erosion. Research has been done to understand and quantify the effect. Most studies have been conducted on slopes and streambanks with woody vegetation. Past research has used a perpendicular root model to predict increase in cohesion, or shear strength, due to the mobilization of roots' tensile strength. Acoustics can be used to monitor internal changes of soil by interacting with soil particles and interstitial fluids. Compressional wave, or p-wave, velocity can be used to predict changes in effective stress …

Nanoionics And Nanocatalysts: Conformal Mesoporous Surface Scaffold For Cathode Of Solid Oxide Fuel Cells, Yun Chen, Kirk Gerdes, Xueyan Song

Faculty & Staff Scholarship

Nanoionics has become increasingly important in devices and systems related to energy conversion and storage. Nevertheless, nanoionics and nanostructured electrodes development has been challenging for solid oxide fuel cells (SOFCs) owing to many reasons including poor stability of the nanocrystals during fabrication of SOFCs at elevated temperatures. In this study, a conformal mesoporous ZrO2 nanoionic network was formed on the surface of La1−xSrxMnO3/yttria-stabilized zirconia (LSM/YSZ) cathode backbone using Atomic Layer Deposition (ALD) and thermal treatment. The surface layer nanoionic network possesses open mesopores for gas penetration, and features a high density of grain boundaries for enhanced ion-transport. The mesoporous nanoionic …

A 3-D Finite Element Model Of The Synthesis, Degradation, And Spatial Spread Of Camp, S Shettleworth, K J. Webb, A V. Phan, T C. Rich

Early Career Technical Journal (ECTJ)

Section 4: Materials; pp. 112-116

Drop Tower Data Filtration Validation, L Lisenbee, David L. Littlefield

Early Career Technical Journal (ECTJ)

Section 2: Design & Manufacturing; pp. 33-37

Cfd Simulation Of Fluid Accumulation In Normal And Injured Alveolar Sacs Models, Parya Aghasafari, Sommer Ihab Anjum, Ramana Pidaparti

Early Career Technical Journal (ECTJ)

Section 1: Bio-Medical/Bioengineering; pp. 15-21

Treatment Of Dissolved Metals For Direct Potable Reuse, Cesar Alberto Alvarez

Open Access Theses & Dissertations

In the process of direct potable reuse (DPR), the bulk of the removal of dissolved metals removal is accomplished by reverse osmosis. This treatment is especially important in wastewater containing contaminants from industrial processes. The goal of this research was to evaluate the performance of DPR with respect to the removal of salinity and dissolved metals to meet drinking standards. Samples were collected from the El Paso Water Utilities Advanced Water Purification pilot system throughout various points in the treatment process. The samples were analyzed for their concentration of ions with Ion Chromatography (IC) and dissolved metals using an Inductively …

Characterization Of High Intensity Turbulent Flows Through Time Resolved Particle Image Velocimetry In A Backward Facing Step Combustor, Martin De La Torre

Open Access Theses & Dissertations

The fundamental understanding of turbulent premixed combustion has taken place as one of the major research topics of interest in industry thanks to advancements in kHz level laser diagnostics such as in Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). Because of said advancements in this technology researchers and the scientific community are now able to expand their understanding of flame studies at high turbulence conditions to acquire a better understanding, and improve models used in turbine design, scram/ram jets, rocket engines, and emissions control. This surge of new technologies has made this topic a high priority one …

Damage Tolerance And Assessment Of Unidirectional Carbon Fiber Composites, Mark David Flores

Open Access Theses & Dissertations

Composites are beginning to be used in a variety of different applications throughout industry. However, certification and damage tolerance is a growing concern in many aerospace and marine applications. Although compression-after-impact have been studied thoroughly, determining a damage tolerance methodology that accurately characterizes the failure of composites has not been established. An experimental investigation was performed to study the effect of stacking sequence, low-velocity impact response, and residual strength due to compression and fatigue. Digital Image Correlation (DIC) captured the strains and deformation of the plate due to compression. Computational investigations integrated non-destructive techniques (C-Scan, X-Ray) to determine the extent …

Combining Interval And Probabilistic Uncertainty In Engineering Applications, Andrew Martin Pownuk

Open Access Theses & Dissertations

In many practical application, we process measurement results and expert estimates. Measurements and expert estimates are never absolutely accurate, their result are slightly different from the actual (unknown) values of the corresponding quantities. It is therefore desirable to analyze how this measurement and estimation inaccuracy affects the results of data processing. There exist numerous methods for estimating the accuracy of the results of data processing under different models of measurement and estimation inaccuracies: probabilistic, interval, and fuzzy. To be useful in engineering applications, these methods should provide accurate estimate for the resulting uncertainty, should not take too much computation time, …

An Investigation Of Abnormal Brain Connectivity Associated With Regions Implicated In Adhd, Roya Gordji

Honors Theses

Research into the unique etiology of attention deficit hyperactivity disorder (ADHD) has in recent years moved from a focus on dysfunction in brain regions to abnormalities between those regions. In this study, we examined the connectivity in brain areas that were deemed to be of particular significance to the disease in terms of their function and already known discrepancies in morphology and connectivity from healthy individuals. The thalamic VA nucleus and the hippocampus were the regions investigated. The data, obtained from the ADHD-200 Sample, consisted of MRI, clinical, and demographic data and were made up of 215 individuals, 117 of …

Anatomical Locality On Haptic Feedback To Attenuate Stuttering, Travis Fortin

Honors Theses

Purpose The purpose of this study was to investigate whether a change in the location of the tactile stimulator would alter the instances of stuttering. Method Each subject was required to read a randomly assigned 300-syllable passage in each of the five assigned speaking conditions, which includes the control, fingers, chest, wrist, and foot. Results The stuttering count for each condition was analyzed by two trained research assistants. The median for the control was 44 syllables, the fingers were 41 syllables, the chest was 35 syllables, the wrist was 44 syllables, and the foot was 23 syllables. An RM-ANOVA was …

Aqueous Reactive Species Induced By A Surface Air Discharge: Heterogenous Mass Transfer And Liquid Chemistry Pathways, D. X. Liu, Z. C. Liu, C. Chen, A. J. Yang, D. Li, M. Z. Rong, H. L. Chen, M. G. Kong

Bioelectrics Publications

Plasma-liquid interaction is a critical area of plasma science and a knowledge bottleneck for many promising applications. In this paper, the interaction between a surface air discharge and its downstream sample of deionized water is studied with a system-level computational model, which has previously reached good agreement with experimental results. Our computational results reveal that the plasma-induced aqueous species are mainly H+, nitrate, nitrite, H2O2 and O-3. In addition, various short-lived aqueous species are also induced, regardless whether they are generated in the gas phase first. The production/loss pathways for aqueous species are quantified for an air gap width ranging …

Optimization Of Fluidized Bed Isothermal Reactor In A Styrene Production Process, Matthew Hamilton Peaster

Honors Theses

The focus of this thesis is to explain the optimization of a fluidized bed isothermal reactor in a styrene production process. The first section of the thesis gives a summary of chemical process optimization in general. The next portion of the thesis gives an introduction to chemical process simulation software, and it explains how simulation software aids in the design and optimization of chemical processes. The third section of the thesis gives a brief overview of an optimization project of a styrene production process that was completed in the previous semester with a group of three. The final section explains …

Optimization Of Single And Multiple Unit Chemical Processes: A Case Study On The Optimization Of A Styrene Plant Design, Piero Bracamonte

Honors Theses

Optimizing a chemical plant revolves around achieving an efficiency that takes into account operating constraints and costs, along with production requirements and addressing environmental concerns. The first part of this thesis focuses on the team's optimization of a styrene production plant. The goal was to determine what changes from the base case minimize cost to produce the required amount of styrene while adhering to operating constraints. The team used PRO/II, a steady state process simulator, in order to simulate multiple unit operations included in the plant. The measure by which proposed design changes were compared was the calculated net present …

First-Year Project Experience In Aerospace: Apogee Determination Of Model Rockets With Explicit Consideration Of Drag Effect, Hüseyin Sarper, Drew Landman, Linda Vahala

Electrical & Computer Engineering Faculty Publications

This paper describes a student team project using model rockets and engines to learn engineering solution methods for determining the apogee of model rocket when the drag effect is considered explicitly instead of estimating its effect later. Model rocketry is a powerful tool for instructors who wish to incorporate science, engineering, and mathematics into a fun, engaging, and challenging activity for the students. The apogee can be determined using a number of distinct methods: trigonometry, onboard altimeters, analytical calculations, and simulation. This paper emphasizes numerical analytical solution using spreadsheet programming instead of a full analytical solution that requires higher mathematics. …

Quasi-Magnetostatic Field Modeling Of Ships In The Presence Of Dynamic Sea Waves, Cody Lonsbury

Theses and Dissertations--Electrical and Computer Engineering

Mechanical stresses placed on ferromagnetic materials while under the influence of a magnetic field are known to cause changes to the permanent magnetization of the material. Modeling this phenomenon is vital to the safety of ocean faring ships. In this thesis, a quasi-strip theory method of computing the nonlinear wave induced motion of a ship is developed, and the fluid pressure on the surface of the hull is used to determine the mechanical stresses. An existing magnetostatic volume integral equation code is used to evaluate the effects of the ship motion and hull stresses. The resulting changes in the magnetic …

Cable Sizing And Its Effect On Thermal And Ampacity Values In Underground Power Distribution, Obinna E. Igwe

Theses and Dissertations--Electrical and Computer Engineering

Over the past decade, underground power distribution has become increasingly popular due to its reliability, safety, aesthetic characteristics, as well as the ever increasing focus on the environmental impacts of the various stages of power generation and distribution. With the technological advances in this area, the process of running these cables have become more economical and efficient.

This thesis explores the practice of grouping multiple three phase cables in a common conduit, using the duct bank process, and analyzes the thermal and ampacity consequences on the individual lines. This analysis is done in an effort to better define and understand …

Information-Theoretic Secure Outsourced Computation In Distributed Systems, Zhaohong Wang

Theses and Dissertations--Electrical and Computer Engineering

Secure multi-party computation (secure MPC) has been established as the de facto paradigm for protecting privacy in distributed computation. One of the earliest secure MPC primitives is the Shamir's secret sharing (SSS) scheme. SSS has many advantages over other popular secure MPC primitives like garbled circuits (GC) -- it provides information-theoretic security guarantee, requires no complex long-integer operations, and often leads to more efficient protocols. Nonetheless, SSS receives less attention in the signal processing community because SSS requires a larger number of honest participants, making it prone to collusion attacks. In this dissertation, I propose an agent-based computing framework using …

Incorporating Machine Vision In Precision Dairy Farming Technologies, Anthony N. Shelley

Theses and Dissertations--Electrical and Computer Engineering

The inclusion of precision dairy farming technologies in dairy operations is an area of increasing research and industry direction. Machine vision based systems are suitable for the dairy environment as they do not inhibit workflow, are capable of continuous operation, and can be fully automated. The research of this dissertation developed and tested 3 machine vision based precision dairy farming technologies tailored to the latest generation of RGB+D cameras. The first system focused on testing various imaging approaches for the potential use of machine vision for automated dairy cow feed intake monitoring. The second system focused on monitoring the gradual …

Test 2158: Case Ih Farmall 130a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2157: Case Ih Farmall 120a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …