Engineering Commons^™

Integrated Scheduling And Control In Discrete-Time With Dynamic Parameters And Constraints, Logan Beal, Damon Petersen, David R. Grimsman, Sean Warnick, John Hedengren

Faculty Publications

Integrated scheduling and control (SC) seeks to unify the objectives of the various layers of optimization in manufacturing. This work investigates combining scheduling and control using a nonlinear discrete-time formulation, utilizing the full nonlinear process model throughout the entire horizon. This discrete-time form lends itself to optimization with time-dependent constraints and costs. An approach to combined SC is presented, along with sample pseudo-binary variable functions to ease the computational burden of this approach. An initialization strategy using feedback linearization, nonlinear model predictive control, and continuous-time scheduling optimization is presented. The formulation is applied with a generic continuous stirred tank reactor …

Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson

Faculty Publications

Dynamic control of radiative surface properties enables optimization of thermal management systems for spacecraft, radiative cooling systems and other applications [1-3]. Various methods of altering the absorption or emission from a surface have been investigated [4-6]. Use of origami-inspired, tessellated surfaces to control apparent radiative surface properties is a promising technology [7-9]. Realizing the full potential of tessellated surfaces to dynamically control apparent radiative surface properties requires convenient methods of calculating apparent properties as a function of tessellation geometry and intrinsic radiative surface properties. This paper focuses on the use of geometry to affect total, hemispherical properties of V-grooves comprised …

Arrhenius Rate Chemistry-Informed Inter-Phase Source Terms (Arciist), Matthew J. Schwaab, Robert B. Greendyke, Bryan J. Steward

Faculty Publications

Currently, in macro-scale hydrocodes designed to simulate explosive material undergoing shock-induced ignition, the state of the art is to use one of numerous reaction burn rate models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these burn rate models are largely based on empirical data and must be recalibrated for every new material being simulated. We propose that the use of Arrhenius Rate Chemistry-Informed Interphase Source Terms (ARCIIST) in place of empirically derived burn models will improve the accuracy for these computational codes. A reacting chemistry model of this form was developed for the cyclic …

Improvements For Vision-Based Navigation Of Small, Fixed-Wing Unmanned Aerial Vehicles, Robert C. Leishman, Jeremy Gray, John F. Raquet, Adam Rutkowski

Faculty Publications

Investigating alternative navigation approaches for use when GPS signals are unavailable is an active area of research across the globe. In this paper we focus on the navigation of small, fixed-wing unmanned aerial vehicles (UAVs) that employ vision-based approaches combined with other measurements as a replacement for GPS. We demonstrate with flight test data that vehicle attitude information, derived from cheap, MEMS-based IMUs is sufficient to improve two different types of vision processing algorithms. Secondly, we show analytically and with flight test data that range measurements to one other vehicle with global pose is sufficient to constrain the global drift …

Will The Real Designer Please Stand Up? [Senior Design], Jay R. Goldberg

Biomedical Engineering Faculty Research and Publications

In the 1950s and 1960s, there was a popular television show called To Tell the Truth, on which three contestants claimed to be a person with an unusual occupation or distinction. Two of them were impostors, and the other was telling the truth. Four panelists asked the contestants questions to determine who was being truthful. After each panelist chose the contestant he or she thought was telling the truth, the host would ask "Will the real _____ please stand up?" To create drama, each contestant would rise at different times and then sit, leaving the contestant with the unusual occupation …

Effects Of Spinal Fusion For Idiopathic Scoliosis On Lower Body Kinematics During Gait, Karen M. Kruger, Christina R. Garman, Joseph J. Krzak, Adam Graf, Sahar Hassani, Sergey Tarima, Peter F. Sturm, Kim W. Hammerberg, Purnendu Gupta, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Objectives

The purpose of this study was to compare gait among patients with scoliosis undergoing posterior spinal fusion and instrumentation (PSFI) to typically developing subjects and determine if the location of the lowest instrumented vertebra impacted results.

Summary of Background Data

PSFI is the standard of care for correcting spine deformities, allowing the preservation of body equilibrium while maintaining as many mobile spinal segments as possible. The effect of surgery on joint motion distal to the spine must also be considered. Very few studies have addressed the effect of PSFI on activities such as walking and even fewer address …

Non-Destructive Evaluation For Composite Material, Desalegn Temesgen Delelegn

Electrical & Computer Engineering Theses & Dissertations

The Nondestructive Evaluation Sciences Branch (NESB) at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) has conducted impact damage experiments over the past few years with the goal of understanding structural defects in composite materials. The Data Science Team within the NASA LaRC Office of the Chief Information Officer (OCIO) has been working with the Non-Destructive Evaluation (NDE) subject matter experts (SMEs), Dr. Cheryl Rose, from the Structural Mechanics & Concepts Branch and Dr. William Winfree, from the Research Directorate, to develop computer vision solutions using digital image processing and machine learning techniques that can help identify …

Analysis Of Bulk Power System Resilience Using Vulnerability Graph, Md Ariful Haque

Computational Modeling & Simulation Engineering Theses & Dissertations

Critical infrastructure such as a Bulk Power System (BPS) should have some quantifiable measure of resiliency and definite rule-sets to achieve a certain resilience value. Industrial Control System (ICS) and Supervisory Control and Data Acquisition (SCADA) networks are integral parts of BPS. BPS or ICS are themselves not vulnerable because of their proprietary technology, but when the control network and the corporate network need to have communications for performance measurements and reporting, the ICS or BPS become vulnerable to cyber-attacks. Thus, a systematic way of quantifying resiliency and identifying crucial nodes in the network is critical for addressing the cyber …

Model-Less Fuzzy Logic Control For The Nasa Modeling And Control For Agile Aircraft Development Program, Keith A. Benjamin

Electrical & Computer Engineering Theses & Dissertations

The NASA Modeling and Control for Agile Aircraft Development (MCAAD) program seeks to develop new ways to control unknown aircraft to make the aircraft development cycle more efficient. More specifically, there is a desire to control an aircraft with an unknown mathematical model using only first principles of flight. In other words, rather than using a rigorously developed mathematical model combined with wind-tunnel tests, a controller is sought which would allow one to bypass the development of a rigorous mathematical model and enter wind-tunnel testing more directly. This paper presents the design of a fuzzy PID controller, governed by a …

Developmental Steps For A Functional Three-Dimensional Cell Culture System For The Study Of Asymmetrical Division Of Neural Stem Cells, Martina Zamponi

Biomedical Engineering Theses & Dissertations

Stem cells are a cell type present during and following development, which possess self- renewal properties, as well as the ability to differentiate into specific cells. Asymmetrical division is the cellular process that allows stem cells to produce one differentiated and one un-differentiated daughter cell during the same mitotic event. Insights in the molecular mechanisms of such process are minimal, due to the absence of effective methods for its targeted study. Currently, traditional methods of investigation include monolayer cell culture and animal models. The first poses structural limitations to the accurate representation of human tissue and cell structures, while animal …

Epithelial Sheet Response To External Stimuli, Yashar Bashirzadeh

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical communication of adherent cells with their micro-environment is mediated by cytoskeletal and adhesion proteins. These mechanical links aid tissues in maintaining their coherence in the context of the surrounding extra cellular matrix (ECM). Epithelial tissues exert force on the ECM through integrin-based junctions and maintain their coherency through E-cadherin-based cell-cell junctions while dynamically undergoing collective migration. Such a complex network of communication involving the cell cytoskeleton and adhesion proteins modulates the tissue's response to external cues. Two distinct forms of such external stimuli are those of electrical and mechanical origin.

Epithelial tissues quickly respond to physiologically relevant electric fields …

Generation Of Large-Volume Diffuse Plasma By An External Ionization Wave From A Single-Electrode Plasma Jet, Seyed Hamid Razavi Barzoki

Electrical & Computer Engineering Theses & Dissertations

A non-thermal transient diffuse plasma can be generated remotely in a nonconductive reduced pressure chamber by an external guided fast ionization wave (FIW). We found that an atmospheric-pressure low-temperature plasma jet (APPJ) can be a source of FIW which transfers an enhanced electric field at the wave front across a reduced pressure Pyrex glass chamber with no electrical connection to the chamber. Here, we studied the formation and propagation of the APPJ plasma, the interaction of atmospheric-pressure guided FIW with a dielectric surface which forms the wall of the reduced-pressure system, and the formation and propagation of the reduce-pressure FIW …

Identification And Optimal Linear Tracking Control Of Odu Autonomous Surface Vehicle, Nadeem Khan

Mechanical & Aerospace Engineering Theses & Dissertations

Autonomous surface vehicles (ASVs) are being used for diverse applications of civilian and military importance such as: military reconnaissance, sea patrol, bathymetry, environmental monitoring, and oceanographic research. Currently, these unmanned tasks can accurately be accomplished by ASVs due to recent advancements in computing, sensing, and actuating systems. For this reason, researchers around the world have been taking interest in ASVs for the last decade. Due to the ever-changing surface of water and stochastic disturbances such as wind and tidal currents that greatly affect the path-following ability of ASVs, identification of an accurate model of inherently nonlinear and stochastic ASV system …

The Influence Of Engineers On Public Policy, Sarah Bouazzaoui

Engineering Management & Systems Engineering Theses & Dissertations

Engineers play a vital role in society and contribute positively to economic growth in various areas, including energy, transportation, telecommunications, and others. In the United States of America, these areas are monitored by public policies that are set by policy actors—mainly lawyers, public administrators and social scientists—at legislative and regulatory levels. In these domains, engineers have a reduced voice with key decision makers on critical engineering issues, and their input is very limited. Their lack of involvement results in costly unintended consequences, affecting both the interest of the profession and the interest of the nation.

Research has shown that increased …

Sequence-Based Simulation-Optimization Framework With Application To Port Operations At Multimodal Container Terminals, Mariam Aladdin Kotachi

Engineering Management & Systems Engineering Theses & Dissertations

It is evident in previous works that operations research and mathematical algorithms can provide optimal or near-optimal solutions, whereas simulation models can aid in predicting and studying the behavior of systems over time and monitor performance under stochastic and uncertain circumstances. Given the intensive computational effort that simulation optimization methods impose, especially for large and complex systems like container terminals, a favorable approach is to reduce the search space to decrease the amount of computation.

A maritime port can consist of multiple terminals with specific functionalities and specialized equipment. A container terminal is one of several facilities in a port …

A Framework For Executable Systems Modeling, Matthew Amissah

Engineering Management & Systems Engineering Theses & Dissertations

Systems Modeling Language (SysML), like its parent language, the Unified Modeling Language (UML), consists of a number of independently derived model languages (i.e. state charts, activity models etc.) which have been co-opted into a single modeling framework. This, together with the lack of an overarching meta-model that supports uniform semantics across the various diagram types, has resulted in a large unwieldy and informal language schema. Additionally, SysML does not offer a built in framework for managing time and the scheduling of time based events in a simulation.

In response to these challenges, a number of auxiliary standards have been offered …

Super Hydrophobicity Of Sputtered Ptfe Films On Nanotextured Aluminum Surface, S Lumjeak, T Lertvanithpo, P Limnonthakul, M Horprathum, P Songsirirtthigul

Journal of Metals, Materials and Minerals

In this research, the superhydrophobic surface was prepared by using the polytetrafluoroethylene (PTFE) thin films which deposited on aluminum (Al) nanotextures. The Al nanotextures have been prepared under different alkaline-treatment concentrations, and deposited with the PTFE thin films by the RF magnetron sputtering technique. During the alkaline treatments, the Al surface was immersed in the potassium hydroxide (KOH) solution with the concentrations of 1 mM to 0.10 mM. Then, the samples of PTFE films were deposited on Al nanotextures were characterized; the crystal structures, chemical compositions, physical morphologies, and surface roughness by photoelectron spectroscopy (PES), field-emission scanning electron microscopy (FE-SEM) …

Aluminium-Sic Composite: Study Of Its Mechanical Properties, D Sánchez-García, A Herrera-Vázquez, J Hinojosa-Torres

Journal of Metals, Materials and Minerals

Cylindrical specimens with geometries and sizes, in agreement with the standard of American Society for Testing Materials (ASTM), they were used to characterize the tension behaviour of the composite. A significant effect of the SiC shape/size on the tensile behaviour of aluminium-based composite was observed, caused by the differences between the superheat (993 K) and the mould temperatures (333 K, 473 K, 623 K) in the melting practice. Ultimate tensile stress and Fracture Toughness factor for the composite showed a numerical advantage over the corresponding ones to the aluminium at a solidification speed of 82.5 K·s-1. At the mould temperature …

Effect Of Tempering Temperature On Microstructure And Mechanical Properties Of Low Alloy Steel In Quenched Tempered Conditions, V Yadav, A K. Singh, G Sahoo

Journal of Metals, Materials and Minerals

The effect of tempering temperature on the microstructure and mechanical properties of a low alloy steel has been investigated using optical microscopy, hardness testing and Charpy V-notch impact testing at -20°C, -40°C and -60°C. At first, the laboratory based study revealed that tempering the specimens at 650°C resulted in lowest hardness with highest impact energy. Based on this, the heat-treated industrial steel showed sufficiently high toughness after Charpy V-notch impact testing at -40°C. Fractography after impact testing showed predominately ductile dimple rupture in the sample tempered at 650°C. The presence of decomposed martesitic laths in prior austenite was noticed in …

Wear Properties Of Boron Added High Strength Low Alloy (Hsla) Sae 8620 Steel, M Musa, A G. Mohammed, A Muhammad

Journal of Metals, Materials and Minerals

The High Strength Low Alloy (HSLA) SAE 8620 steel with different contents of boron in ppm rate used in bearings, automotive gearing and automotive body components applications were studied. We report the relationship between wear properties, microstructural characterization and hardness properties of the steel. The steel chemical composition is selected to obtain relatively high mechanical properties with different boron contents. Increasing the normalization temperature and boron content, shows ferrite grain-size becomes larger when compared to lower normalization temperatures and boron content. With differences in boron content, only 2 HBN were measured from the average hardness of 3.3 ppm and 13.5 …

Crystalline Silica In Compressed Rice Hull Coke Ash, T Okutani, E Ichikawa, H Nagai, T Hashimoto, T Makihata

Journal of Metals, Materials and Minerals

Compressed rice hull coke was produced by compressing rice hulls ground to less than 200 µm diameter at 1.22x106 N/m2 and 310˚C with an oxygen deficient atmosphere. The compressed rice hull coke had a 5 cm outer diameter, a 1.5 cm inner diameter and 35 cm length. The density of the coke is 1.2, and, the heat value is 16570 kJ·kg-1. In this study, 2 kg coke was combusted at the average temperature of 850˚C for 104 min with a maximum temperature of 860˚C. The ash was colored black-grey, and the form remained coke. The ash contained 95.4% silica with …

Enhancement Of Mechanical, Thermal And Antibacterial Properties Of Sisal/Phbv Biocomposite By Fibre Modification, T Kittikorn, R Malakul, E Stromberg, M Ek, S Karlsson

Journal of Metals, Materials and Minerals

Lignocellulosic biocomposite is a promising biodegradable materials, though improvement of the interfacial adhesion between cellulose fibre and polymer matrix is still challenged. Therefore, this work investigated the effect of propionylation of sisal reinforced fibre in the sisal/polyhydroxybutyrate-co-valerate (PHBV) biocomposite. Propionylation involved esterification substitution of propionic anhydride to hydroxyl group of sisal fibre, where ester group (COOR) of propionylated fibre was successfully observed by Fourier transform Infrared spectroscopy (FTIR). Then mechanical and thermal properties were evaluated and biodegradation characteristics were assessed. The tensile strength and modulus of propionylated sisal/PHBV biocomposite were greater than unmodified sisal/PHBV, which revealed better compatibility at the …

Investigation Of Erosive Wear Behaviour Of Tungsten Carbide Cobalt Coated Metal Matrix Composites Using Ann, M Pasha, M Kaleemulla

Journal of Metals, Materials and Minerals

An artificial neural network (ANN) model was employed on erosive wear result of aluminium 7034 T6 reinforced with different weight percentage of Al2O3 and SiC with tungsten carbide cobalt (WC-Co) coated composites. WC-Co in the form of powder was pretreated before coating, to identify the inflence of pretreatment on the substrate. The WC-Co coating was deposited with high velocity oxy fuel (HVOF) sparay method. The microstructural examination was carried through scanning electron microscope (SEM) and to identify the elemental composition of coated specimens, energy dispersive X-ray analysis (EDX) was used. These material charecterisation shows that pretreated WC-Co coated Al 7034 …

Carboxymethylchitosan-Based Hydrogels Crosslinked With Polydimethylsiloxane, N Rodkate, N Deepuppha, B Rutnakornpituk, M Rutnakornpituk

Journal of Metals, Materials and Minerals

Synthesis and properties of hydrophilic carboxymethylchitosan (CMC) hydrogels containing hydrophobic polydimethylsiloxane (PDMS) were herein presented. Fourier transform infrared spectroscopy indicated that PDMS can covalently bound to CMC chains with the use of hexamethylene-1,6-di-(aminocarboxysulfonate) (HDA), a water soluble crosslinker. Also, according to scanning electron microscopy, PDMS microphases with the size of 0.2-0.5 µm in diameter were thoroughly dispersed in CMC matrix. Addition of PDMS improved properties of the CMC hydrogels including increasing water vapor permeability and water swellability, improving tensile properties and increasing surface hydrophobicity. PDMS with different amounts (1-20 wt%) and molecular weights (2,000 and 8,000 g·mol-1) were added into …

Thermal And Mechanical Properties Of An Epoxidized Natural Rubber Composite Containing A Li/Cr Co-Doped Nio-Based Filler, B Khumpaitool, S Utara, P Jantachum

Journal of Metals, Materials and Minerals

Li and Cr co-doped NiO-based (LCNO) filler was successfully synthesized by the sol-gel process using metal nitrate compounds as starting materials and citric acid as a crosslinking agent, followed calcination at a temperature of 1000˚C for 3 h. Composites of Li and Cr co-doped NiO/epoxidized natural rubbers with 25 mol% epoxidation (abbreviated as LCNO/ENR-25) were prepared by mixing using a two-roll mill. The ENR-25 was blended with 0.5, 1, 2 and 3 phr (parts per hundred of rubber) of LCNO and the specimens were shaped at 160˚C using compression molding. The LCNO/ENR-25 composites were characterized by thermogravimetric analysis (TGA), Fourier-transform …

Simple And Rapid Preparation Of Cuo Film Using Silar Process For Application As Hole-Transporting Layer In P-I-N Perovskite Solar Cell, S Wongrerkdee, K Hongsith, S Choopun, K Lohawet, P Kumno

Journal of Metals, Materials and Minerals

Copper oxide (CuO) films are considered to be an alternative metal oxide semiconductor for hole-transporting layer application in p-i-n perovskite solar cells due to their unique properties including intrinsic p-type materials and energy band level matching. The films can be synthesized using several methods such as sputtering, solution process and spin-coating processes. However, using the successive ionic layer adsorption and reaction (SILAR) process to prepare a CuO hole-transporting layer in p-i-n perovskite solar cells is still underreported. Thus, this study prepared the SILAR processed CuO films and applied as a hole-transporting layer in p-i-n perovskite solar cells. The results showed …

Utilization Of Coal Fly Ash As A Raw Material For Refractory Production, R Sukkae, S Suebthawilkul, B Cherdhirunkorn

Journal of Metals, Materials and Minerals

In this research, fireclay bricks were produced using fire clay and coal fly ash as raw materials. Coal fly ash was added to the mixture from 10-50 wt%. The disk shape samples were sintered at the temperatures of 1,100-1,400°C. The mechanical property, thermal property, phase structure and microstructure of the fireclay bricks were studied. It was found that coal fly ash can be used in the fabrication of fireclay bricks. The lower linear shrinkage and lower thermal conductivity were obtained as the higher amount of coal fly ash was added. However, bulk density and strength were lower in the samples …

Eggshell Waste: An Effective Source Of Hydroxyapatite For Photocatalyst, S Ummartyotin, H Manuspiya

Journal of Metals, Materials and Minerals

Interest in eggshell waste and its modification has been increasing rapidly. The outstanding property of eggshell waste is its high calcium carbonate content. This can be transformed to calcium oxide, and can provide a source of hydroxyapatite. As interest in clean technology has grown, the use of eggshell waste has become a focus of research. The objective of this review article is to characterize eggshell waste, describe the preparation of hydroxyapatite from eggshell waste and its modification, and discuss the use of hydroxyapatite as a photocatalyst.

Recent Developments In The Field Of Metal Foam-Polymer Hybrid Materials: A Brief Overview, A Chaturvedi

Journal of Metals, Materials and Minerals

In this paper, a brief overview of the various techniques employed for the preparation of metal foam-polymer hybrid/composite materials including infiltration/penetration and adhesive joining is given. Scanning electron microscopy (SEM) micro structural characterization method and various dependent mechanical properties such as stress-strain diagram, energy absorption etc is described. In addition, some possible applications of such materials are discussed. The paper intends to inform as well as educate the reader about the various aspects of this emerging field in a lucid manner.

Investigation Of The Skin Effect In Alternating Currents, Matthew Liang

The International Student Science Fair 2018

My research is on the investigation of the skin effect in alternating currents. The skin effect is when an alternating current tends to flow on the surface of the conductor, such that the current density is highest near the surface, and decreases with greater depths in the conductor. This is due to the alternating current inducing changing magnetic fields, which in turn induces currents that oppose the original flow of current, resisting the current flowing through the centre the most. This reduces the effective cross-sectional area of the conductor and increases the resistance, causing increased power losses. This effect becomes …