Engineering Commons^™

Nonlinear Optics And Bio-Sensing With Silicon Nitride Waveguides, Subrata Das

Electrical Engineering Dissertations - Archive

Silicon Nitride (SiN) is a CMOS compatible optical material that can be used for both linear and nonlinear optics applications. SiN has high refractive index (1.99-2.0) and low two photon absorption (TPA) coefficient. As a result, SiN can be used as a core material to guide and bend light, and the development of compact on-chip SiN optical devices exploiting both linear and nonlinear optical phenomena is very much feasible. In this thesis work, two independent research projects are presented. The first work presents the design of a hybrid SiN/Polymer slot waveguide for second-harmonic generation (SHG) of a 1550-nm wave at …

A Governance Perspective For System-Of-Systems, Polinpapilinho F. Katina, Charles B. Keating, James A. Bobo, Tyrone S. Toland

Engineering Management & Systems Engineering Faculty Publications

The operating landscape of 21st century systems is characteristically ambiguous, emergent, and uncertain. These characteristics affect the capacity and performance of engineered systems/enterprises. In response, there are increasing calls for multidisciplinary approaches capable of confronting increasingly ambiguous, emergent, and uncertain systems. System of Systems Engineering (SoSE) is an example of such an approach. A key aspect of SoSE is the coordination and the integration of systems to enable ‘system-of-systems’ capabilities greater than the sum of the capabilities of the constituent systems. However, there is a lack of qualitative studies exploring how coordination and integration are achieved. The objective of this …

2-Axis Electric Off-Road Bucket Seat Bases, Brennan K. Slater, Alexander P. Croteau, Spencer M. Kubik

Mechanical Engineering

Off-road vehicle bucket seats are currently restricted to a single position relative to the floor of the vehicle. Drivers and riders desire the ability to adjust their seat position to increase comfort and allow for a greater size range of riders to fit safely within the cabin or roll cage. To develop a viable solution, the team has gone through an extensive design process and has constructed a functioning prototype. This Final Design Report encapsulates the entire design process and concludes with recommendations for changes we would make looking both back in review as well as moving forward with further …

Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

With the continuous development of nanomaterials, how to improve the conversion efficiency of DSSCs has been the focus of scholars. Nano-TiO2 material is a wide bandgap semiconductor with a bandgap of 3.2eV. It exhibits good performance in dye adsorption, charge separation, electron transport, etc., and has good chemical stability and strong acid and alkali resistance. Therefore, it was always the material of choice for the preparation of photoanodes. In this paper, different thicknesses of TiO2 NRs barrier layers were prepared on FTO substrates by solvothermal method and two-step spin coating method, and their electrochemical and photoelectric properties were tested by …

Synthesis Of Metakaolin-Based Geopolymer And Its Performance As Sole Stabilizer Of Expansive Soils, Rinu Ann Samuel

Civil Engineering Dissertations - Archive

Expansive soils have been stabilized using conventional soil stabilizers such as lime and cement for many decades. These conventional stabilizers form cementitious productions that enhance the strength properties and reduce the swelling and shrinkage potential of expansive soils. However, the energy-intensive production operations of conventional soil stabilizers release substantial amounts of harmful greenhouse gases into the atmosphere. In addition, conventional soil stabilizers are also prone to durability issues, which make them somewhat ineffective as long-term solutions. Furthermore, the use of calcium-based stabilizers cause excessive swelling and shrinkage in sulfate-bearing subgrade soils due to the formation of highly expansive minerals like …

Development Of A Flexible Pavement Design Protocol For The Uae Based On The Mechanistic-Empirical Pavement Design Guide, Ammar Hassan Alalkim Alzaabi

Civil Engineering Dissertations - Archive

The Ministry of Infrastructure Development in the UAE has used the AASHTO 1993 Pavement Design Guide for the design of new flexible pavement structures for many years. An improved pavement design method, called the Mechanistic-Empirical Pavement Design Guide (MEPDG) was developed by AASHTO in their effort to update the empirical method used in 1993 Guide. The project was initiated by the National Cooperative Highway Research Program (NCHRP) 1-37A project. It is based on mechanistic-empirical analysis of the pavement structure to predict the performance of the pavements subject to pavement structure and materials, traffic and environmental conditions. The development allowed for …

Seismic Response And Deformation Analyses Of Earthen Dams, Leila Mosadegh

Civil Engineering Dissertations - Archive

Assessment of the response of earthen structures, such as dams and levees, during earthquake events, is crucially important to geotechnical engineers. It is imperative to perform seismic response analysis to assess the stability and serviceability of these structures during probable seismic events. Before performing a seismic response analysis, an engineer or a researcher needs to select between two-dimensional (2D) plane strain analysis and a computationally intensive three dimensional (3D) analysis of an infrastructure. The 3D analysis should closely capture the behavior of infrastructure seismic response than a simplistic 2D analysis. Furthermore, a dilemma remains regarding the choice of a suitable …

Multivariate Time Series Pattern Recognition Using Machine Learning And Deep Learning Methods, Sai Abhishek Devar

Industrial, Manufacturing, and Systems Theses - Archive

In this research work, we have implemented machine learning & deep-learning algorithms on real-time multivariate time series datasets in the manufacturing & health care fields. The research work is organized in two case-studies. The case study-1 is about rare event classification in multivariate time series in a pulp and paper manufacturing industry, data was collected of multiple sensors at each stage of production line, the data contains a rare event of paper break that commonly occurs in the industry. For preprocessing we have implemented sliding window approach for calculating first order difference method to capture the variation in the data …

3d Janus Plasmonic Helical Nanoapertures For Polarization-Encrypted Data Storage, Yang Chen, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Helical structures have attracted considerable attention due to their inherent optical chirality. Here, we report a unique type of 3D Janus plasmonic helical nanoaperture with direction-controlled polarization sensitivity, which is simply fabricated via the one-step grayscale focused ion beam milling method. Circular dichroism in transmission of as large as 0.72 is experimentally realized in the forward direction due to the spin-dependent mode coupling process inside the helical nanoaperture. However, in the backward direction, the nanoaperture acquires giant linear dichroism in transmission of up to 0.87. By encoding the Janus metasurface with the two nanoaperture enantiomers having specified rotation angles, direction-controlled …

Pore Elimination Mechanisms During 3d Printing Of Metals, S. Mohammad H. Hojjatzadeh, Niranjan D. Parab, Wentao Yan, Lianyi Chen, For Full List Of Authors, See Publisher's Website.

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a 3D printing technology that can print metal parts with complex geometries without the design constraints of traditional manufacturing routes. However, the parts printed by LPBF normally contain many more pores than those made by conventional methods, which severely deteriorates their properties. Here, by combining in-situ high-speed high-resolution synchrotron x-ray imaging experiments and multi-physics modeling, we unveil the dynamics and mechanisms of pore motion and elimination in the LPBF process. We find that the high thermocapillary force, induced by the high temperature gradient in the laser interaction region, can rapidly eliminate pores from the …

A Comparison Of The Army Corps Of Engineers Hydrologic Modeling System And Autodesk Storm And Sanitary Analysis For Hydraulic And Hydrologic Analysis And Design, Foster Josef Heifetz Campbell

Master's Theses

Hydrological and hydraulic effects of urban development is one of the key issues of study for improved water management. The addition of impervious surfaces to once pervious land and re-routing open channels and flow paths can cause flooding or declining water levels within a watershed. Many studies of these issues have found that there can be multiple factors causing hydrological and hydraulic impacts, and it can be hard to analyze and develop effective solutions without appropriate drainage software packages. However, there are multiple software packages available for use, and determining the correct one to use for a specific challenge can …

Hybrid Iii 95th Percentile Large Male Finite Element Model Neck Alteration, Eric Riley Day

Master's Theses

The motivation behind the project was to update the Livermore Software Technology Corporation (LSTC) Hybrid III 95th percentile finite element model, such that the neck assembly response under varying simulated loading conditions equals that of the federally regulated Hybrid III 95th percentile anthropomorphic testing device (ATD).

The family of Hybrid III crash test dummies approximate the physical properties and response of the human body in a frontal automotive crash. The Hybrid III is used to assess the effectiveness of vehicle restraint systems. LSTC offers Hybrid III finite element models for use in their Multiphysics simulation software package, LS-DYNA. The Hybrid …

Development Of An Analysis Tool And Weight Estimation Method For Aircraft Wing Structures, Kevin M. Barton

Master's Theses

The goal of this effort was to build an analysis tool for aircraft wings and incorporate it into a program that optimizes the wing structure for the lowest weight for the conceptual design phase. The analysis tool calculates the internal stresses in primary load carrying members using established analysis methods for semimonocoque beams. Via a Graphical User Interface (GUI) built in MATLAB, the user can define the structural layout and material properties of the load carrying members. The program requires a degenerate geometry model built with Vehicle Sketch Pad (OpenVSP) to define the outer mold line (OML) of the wing, …

Design, Modeling And Control Of A Two-Wheel Balancing Robot Driven By Bldc Motors, Charles T. Refvem

Master's Theses

The focus of this document is on the design, modeling, and control of a self-balancing two wheel robot, hereafter referred to as the balance bot, driven by independent brushless DC (BLDC) motors. The balance bot frame is composed of stacked layers allowing a lightweight, modular, and rigid mechanical design. The robot is actuated by a pair of brushless DC motors equipped with Hall effect sensors and encoders allowing determination of the angle and angular velocity of each wheel. Absolute orientation measurement is accomplished using a full 9-axis IMU consisting of a 3-axis gyroscope, a 3-axis accelerometer, and a 3-axis magnetometer. …

Electropermeabilization Does Not Correlate With Plasma Membrane Lipid Oxidation, Olga Michel, Andrei G. Pakhomov, Maura Casciola, Jolanta Saczko, Julita Kulbacka, Olga N. Pakhomova

Bioelectrics Publications

The permeabilized condition of the cell membrane after electroporation can last minutes but the underlying mechanisms remain elusive. Previous studies suggest that lipid peroxidation could be responsible for the lasting leaky state of the membrane. The present study aims to link oxidation within the plasma membrane of live cells to permeabilization by electric pulses. We have introduced a method for the detection of oxidation by ratiometric fluorescence measurements of BODIPY-C11 dye using total internal reflection fluorescence (TIRF) microscopy, limiting the signal to the cell membrane. CHO-K1 cells were cultured on glass coverslips coated with an electroconductive indium tin oxide (ITO) …

The Capacity Of Chennai International Airport: A Study, K P Sooraj

Manipal Journal of Science and Technology

This paper discusses a case study of the capacity of the Chennai International Airport. The capacity of an airport is an important determinant for implementation of Air Traffic Flow Management (ATFM), departure/arrival slot allocation, etc. and is a key input while estimating when the airport will saturate, in order to plan additional infrastructure, at places where catchment area population is not the limiting factor. The simulation model layout of the airport was considered for the study. Total airport delay such as gate delay, TWY delay, seq. delay, RWY delay, posing delay, and total delay for the base model and capacity …

Portable Electrochemical System For Flexible Hybrid Electronics, Anthony Joseph Hanson

Masters Theses

This work focuses on the fabrication and design of a portable electrochemical sensing system for flexible hybrid electronic (FHE) sensors. A three-electrode chemical sensor was fabricated using copper tape on polyethylene terephthalate (PET) substrate, using laser etching process. An electronic circuit was designed to measure the sensor response through electrochemical techniques to detect different concentrations of glucose. The device was calibrated to give the user a concentration value in 5 seconds. The system was also designed to preform tests such as cyclic voltammogram and chronoamperogram for various chemicals. A Bluetooth Low Energy module was used to wirelessly transmit the results …

Behavior Of Hollow-Core Composite Bridge Columns Having Slender Inner Steel Tubes, Mohanad M. Abdulazeez, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper experimentally investigates the seismic behavior of three large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) columns. An HC-FCS column consisted of a concrete shell sandwiched between an outer glass fiber-reinforced polymer (GFRP) tube and an inner steel tube. Both tubes provided continuous confinement for the concrete shell along with the height of the column. The columns had two different steel tube diameter-to-thickness (Ds/ts) ratios of 85, and 254. Each steel tube was embedded into the footing, with an embedded length of 1.25-1.6 times its diameter, while the GFRP tube was not embedded into the footing. Two columns were tested as as-built …

Microwave-Assisted And One-Step Synthesis Of Peg Passivated Fluorescent Carbon Dots From Gelatin As An Efficient Nanocarrier For Methotrexate Delivery, Nasser Arsalani, Parinaz Nezhad-Mokhtari, Esmaiel Jabbari

Faculty Publications

A green and simple process for preparing the polyethylene glycol passivated fluorescent carbon dots (CDs-PEG) have been studied by a microwave pyrolysis method, using gelatin and PEG as starting materials. This method is very effective for development of carbon-based quantum dots from gelatin with high quantum yield (QY). The synthesized CDs-PEG were found to emit blue photoluminescence (PL) with a maximum QY of 34%. At the following research, we investigated the effect of the presence of PEG on PL intensity, and the result showed that CDs-PEG becomes stronger PL properties than pure CDs from gelatin. The synthesized CDs-PEG were characterized …

Bioresorbable Composite Stents For Enhanced Response Of Vascular Smooth Muscle Cells, Hozhabr Mozafari

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

Formation of arterial plaque and stenosis is one of the main cardiovascular disease risk factors. Stenting is a popular approach to increase the inner diameter of the artery and provide an acceptable lumen gain. This is achieved by applying internal pressure to the arterial wall. Despite the desirable outcomes of this procedure, there are complexities and challenges that are being discussed among scholars in this area. Restenosis is one of these complications, in which smooth muscles cell start proliferation and remodeling in response of induced mechanical stresses. Another important issue is the placement of the stent and possible migration due …

Image Classification Using Fuzzy Fca, Niruktha Roy Gotoor

School of Computing: Dissertations, Theses, and Student Research

Formal concept analysis (FCA) is a mathematical theory based on lattice and order theory used for data analysis and knowledge representation. It has been used in various domains such as data mining, machine learning, semantic web, Sciences, for the purpose of data analysis and Ontology over the last few decades. Various extensions of FCA are being researched to expand it's scope over more departments. In this thesis,we review the theory of Formal Concept Analysis (FCA) and its extension Fuzzy FCA. Many studies to use FCA in data mining and text learning have been pursued. We extend these studies to include …

Environmental Sustainability Assessment Of Small Nebraska Mechanical Water Resource Recovery Facilities: Impacts Of Construction And Operations, Sussan Moussavi

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Many small, rural communities struggle with aging or inadequate water resource recovery facilities (WRRFs), and face challenges in constructing and operating such systems. Although existing literature has provided insight into the environmental sustainability of large systems including both the construction and operational phases, these studies have not examined small systems in adequate depth or breadth. The environmental impacts associated with construction may be notable for small WRRFs since the initial construction can be a larger share of the total life cycle environmental impact.

The goal of this work is to provide the environmental sustainability profiles of 12 mechanical WRRFs in …

Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque

School of Computing: Dissertations, Theses, and Student Research

Landing an unmanned aerial vehicle (UAV) on a moving platform is a challenging task that often requires exact models of the UAV dynamics, platform characteristics, and environmental conditions. In this thesis, we present and investigate three different machine learning approaches with varying levels of domain knowledge: dynamics randomization, universal policy with system identification, and reinforcement learning with no parameter variation. We first train the policies in simulation, then perform experiments both in simulation, making variations of the system dynamics with wind and friction coefficient, then perform experiments in a real robot system with wind variation. We initially expected that providing …

Synergistic Effect Of Nanocoatings For Corrosion And Wear Protection Of Steel Surfaces, Jaime Taha-Tijerina, Laura Peña Parás, Antonio Sánchez Fernández, Demófilo Maldonado Cortés, Pablo Sarmiento Barbosa, Jesús Rolando Adán López

Informatics and Engineering Systems Faculty Publications

The purpose of this paper is to evaluate the corrosion and wear protection of a steel substrate by epoxy vinyl ester nanocomposite coatings with Zn and TiO2 nanoparticle fillers. Steel substrates were coated with epoxy vinyl ester nanocomposites, varying Zn and TiO2 nanofiller concentrations and combinations of both nanoparticles. Corrosion resistance was evaluated by salt spray fog test during 480 h, according to ASTM B-117. The degree of damage was obtained quantitatively by measuring the enhancement in corroded area compared to the scribe mark. Tribological evaluation was performed with a ball-on-disk tribotester, according to ASTM G-99. Results showed that the …

Machine Learning Applications To Predict Road Crash And Soccer Game Outcomes, Lu Bai

Master's Theses

Machine learning has become a cutting-edge and widely studied data science field of study in recent years across many industries and disciplines. In this thesis, two problems (1- crash severity prediction, 2- soccer game outcome prediction.) were investigated by using a set of machine learning approaches, namely: Ridge regression, Lasso Regression, Support Vector Machine (SVM), Neural Network (NN), Random Forest (RF).

The first study is focused on investigating the critical factors affecting crash severity on a comprehensive time-series state-wide traffic crash data. The dataset covers crashes occurred in the state of Connecticut between 1995 and 2014. Traffic crashes are an …

Measurement Of Polishing Rate As A Function Of Pad-Independent Abrasive Friction For Chemical Mechanical Polishing, Christopher Mcgowan

Master's Theses

As features on integrated circuits continue to grow smaller, they become more susceptible to damage from sequential planarization steps during fabrication. As planarization (known as chemical mechanical planarization, or simply CMP) is preformed multiple times and on every stage of fabrication, potential damage from it represents a significant financial risk, motivating a more fundamental understanding of the material removal process. CMP typically consists of a stiff polymer pad being used to bring a chemically active colloidal suspension of nanoscale particles into contact and relative motion with the substrate to be polished. For narrow sets of conditions, CMP is typically seen …

Corrosion Of Ecaped Magnesium Alloys And Its Background: A Review, G Manjunath Naik, N Sannayellappa, S Selvin Satheesh Kumar

Journal of Metals, Materials and Minerals

The aim of this review article is to provide a brief mechanistic overview of magnesium alloys, equal channel angular pressing and corrosion behavior of un-ECAPed and ECAPed Mg alloys. The considerate of the corrosion processes of ECAPed Mg alloys builds upon interpretation of the corrosion of fine-grain magnesium alloys. This provides an understanding of the effect of grain size on corrosion of Mg alloys. This deep understanding is essential as a foundation if we are to produce corrosion-resistant magnesium alloys. Considerable has previously been accomplished, but there is enormous scope for development. This present concise review can provide a foundation …

Corrosion Behaviors Of Ship Structural Steel In Simulated Marine Tidal Environment, N Jaiyos, E Viyanit, P Mungsantisuk, K Sirivedin

Journal of Metals, Materials and Minerals

The tidal zone is severe marine environment for steel structures due to its wet-dry cyclic corrosion pattern. Regarding a specific application for inner ship hull, ship structural steel is always prone to corrosion dealing with three marine environments, including atmospheric, tidal, and immersion zones. Therefore, the current study aimed to investigate corrosion behaviors of two commercial ship structural steels, i.e. alloys A and B, which were exposed to simulated marine tidal environment. The effects of specimen arrangements designated as the isolated short-scale and vertical long-scale specimens were also determined. Based on weight loss determination, it revealed that the corrosion rates …

Effect Of Post Weld Heat Treatment Soaking Time On Microstructure And Mechanical Properties Of Tig Welded Grade 91 Steel, K Mithun, K Saraswathamma, D K. Verma

Journal of Metals, Materials and Minerals

Development of new alloy materials is in progress to improve thermal efficiency of supercritical boilers. One of such material is modified 9Cr-1Mo (Grade 91) martensitic alloy steel referred as T/P91. This material is extensively used in high temperature applications such as fabrication of superheater, reheater and economizer sections of a boiler. The present study is made to find the effect of post weld heat treatment (PWHT) soaking time on microstructure and mechanical properties of TIG welded ASTM A213 Grade 91 steel plate. Experiments were conducted for PWHT at 760°C for different soaking time such as 2, 4 and 6 hours …

Synthesis And Luminescence Properties Of Camoo4:Sm3+ Phosphors For Orange Photonic Materials, N Luewarasirikul, J Kaewkhao, H Kim

Journal of Metals, Materials and Minerals

The series of CaMoO4 samples with different melting temperature (600, 700, 800 and 900°C) were synthesized in this work to investigate their phase structures by X-ray diffraction (XRD). The XRD result confirmed that the crystalline structures of the phosphors were obtained at 800°C (tetragonal structure with I41/a space group). Then, the series of Ca1-xMoO4:Smx (where x = 0.005, 0.010, 0.015, 0.020, 0.025 and 0.030) were prepared by solid-state reaction method to study their luminescence properties. The absorption spectra, recorded in UV, Vis and NIR regions, showed peaks at 405, 465, 952, 1096, 1252, 1405, 1513, 1573 and 1629 nm. The …