Engineering Commons^™

New Flow Assurance System With High Speed Subsea Fiber Optic Monitoring Of Pressure And Temperature, John Hedengren, David Brower, J. Conrad Wilson, Geoff High, Karl Witherow

Faculty Publications

Subsea production control systems are instrumented to constantly monitor flowline pressure and temperature at key locations to prevent plugging and introduce mitigating control strategies. New fiber optic sensors with ruggedized construction and non-electrical components are subjected to accelerated aging tests and deployed in several installations with long service life. An overview of current progress with fiber optic technology is provided for fatigue monitoring, temperature, pressure, and strain sensing. Recent developments include improved service life, novel bonding methods, pipeline sensor station improvements, sensor calibration, and long-term fatigue analysis.

The latest advancements are validated on multiple installations on a subsea tieback in …

Special Issue: Combined Scheduling And Control, John Hedengren, Logan Beal

Faculty Publications

This Special Issue (SI) of Processes, “Combined Scheduling and Control,” includes approaches to formulating combined objective functions, multi-scale approaches to integration, mixed discrete and continuous formulations, estimation of uncertain control and scheduling states, mixed integer and nonlinear programming advances, benchmark development, comparison of centralized and decentralized methods, and software that facilitates the creation of new applications and long-term sustainment of benefits. Contributions acknowledge strengths, weaknesses, and potential further advancements, along with a demonstration of improvement over current industrial best-practice.

Comparison Of Plume Dynamics For Laser Ablated Metals: Al And Ti, William A. Bauer, Glen P. Perram, Timothy J. Haugan

Faculty Publications

Emissive plumes from pulsed laser ablation of bulk Ti and Al from KrF laser irradiation at laser fluence up to 3.5 J/cm² and argon background pressures of 0–1 Torr have been observed using gated intensified charged-coupled device imagery. Mass loss for Ti increases from 0.1 to 0.8 μg/pulse as pulse energy increase from 174 to 282 mJ/pulse (35–170 photons/atom) and decreases by ∼30% as pressure increases from vacuum to 1 Torr. Early plume energies are described by the free expansion velocities of 1.57 ± 0.02 and of 1.81 ± 0.07 cm/μs for Ti and Al, respectively, …

Demonstration Of Versatile Whispering-Gallery Micro-Lasers For Remote Refractive Index Sensing, Lei Wan, Hengky Chandrahalim, Jian Zhou

Faculty Publications

We developed chip-scale remote refractive index sensors based on Rhodamine 6G (R6G)-doped polymer micro-ring lasers. The chemical, temperature, and mechanical sturdiness of the fused-silica host guaranteed a flexible deployment of dye-doped polymers for refractive index sensing. The introduction of the dye as gain medium demonstrated the feasibility of remote sensing based on the free-space optics measurement setup. Compared to the R6G-doped TZ-001, the lasing behavior of R6G-doped SU-8 polymer micro-ring laser under an aqueous environment had a narrower spectrum linewidth, producing the minimum detectable refractive index change of 4 x 10⁻⁴ RIU. The maximum bulk refractive index sensitivity (BRIS) …

Aspie: A Framework For Active Sensing And Processing Of Complex Events In The Internet Of Manufacturing Things, Shaobo Li, Weixing Chen, Jie Hu, Jianjun Hu

Faculty Publications

Rapid perception and processing of critical monitoring events are essential to ensure healthy operation of Internet of Manufacturing Things (IoMT)-based manufacturing processes. In this paper, we proposed a framework (active sensing and processing architecture (ASPIE)) for active sensing and processing of critical events in IoMT-based manufacturing based on the characteristics of IoMT architecture as well as its perception model. A relation model of complex events in manufacturing processes, together with related operators and unified XML-based semantic definitions, are developed to effectively process the complex event big data. A template based processing method for complex events is further introduced to conduct …

A Novel Evolutionary Algorithm For Designing Robust Analog Filters, Shaobo Li, Wang Zou, Jianjun Hu

Faculty Publications

Designing robust circuits that withstand environmental perturbation and device degradation is critical for many applications. Traditional robust circuit design is mainly done by tuning parameters to improve system robustness. However, the topological structure of a system may set a limit on the robustness achievable through parameter tuning. This paper proposes a new evolutionary algorithm for robust design that exploits the open-ended topological search capability of genetic programming (GP) coupled with bond graph modeling. We applied our GP-based robust design (GPRD) algorithm to evolve robust lowpass and highpass analog filters. Compared with a traditional robust design approach based on a state-of-the-art …

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

Faculty Publications

Multiple reflections in a cavity geometry augment the emission and absorption of the cavity opening relative to a flat surface in a phenomenon known as the cavity effect. The extent of the cavity effect is quantified using apparent absorptivity and apparent emissivity. Analysis of complicated thermal systems is simplified through application of apparent radiative properities to cavity geometries. The apparent radiative properties of a specularly-reflecting, gray, isothermal V-groove have been derived analytically, but these results have not been validated experimentally or numerically. Additionally, the model for apparent absorptivity of an infinite V-groove subjected to partial illumination in the presence of …

Symmetric Equations For Evaluating Maximum Torsion Stress Of Rectangular Beams In Compliant Mechanisms, Guimin Chen, Larry L. Howell

Faculty Publications

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the cross-section (i.e., the thickness and the width). After reviewing the available equations, two thickness-to-width ratio independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design insights are obtained. These equations, together with the previous work on symmetric …

Mechanical And Geometrical Determinants Of Wall Stress In Abdominal Aortic Aneurysms: A Computational Study, Dara Azar, Donya Ohadi, Alexander Rachev, John F. Eberth, Mark J. Uline, Tarek Shazly

Faculty Publications

An aortic aneurysm (AA) is a focal dilatation of the aortic wall. Occurrence of AA rupture is an all too common event that is associated with high levels of patient morbidity and mortality. The decision to surgically intervene prior to AA rupture is made with recognition of significant procedural risks, and is primarily based on the maximal diameter and/or growth rate of the AA. Despite established thresholds for intervention, rupture occurs in a notable subset of patients exhibiting sub-critical maximal diameters and/or growth rates. Therefore, a pressing need remains to identify better predictors of rupture risk and ultimately integrate their …

Monte Carlo Simulations Of Three-Dimensional Electromagnetic Gaussian Schell-Model Sources, Milo W. Hyde Iv, Santasri Bose-Pillai, Olga Korotkova

Faculty Publications

This article presents a method to simulate a three-dimensional (3D) electromagnetic Gaussian-Schell model (EGSM) source with desired characteristics. Using the complex screen method, originally developed for the synthesis of two-dimensional stochastic electromagnetic fields, a set of equations is derived which relate the desired 3D source characteristics to those of the statistics of the random complex screen. From these equations and the 3D EGSM source realizability conditions, a single criterion is derived, which when satisfied guarantees both the realizability and simulatability of the desired 3D EGSM source. Lastly, a 3D EGSM source, with specified properties, is simulated; the Monte Carlo simulation …

In Situ Uv-Visible Assessment Of Iron-Based High-Temperature Water-Gas Shift Catalysts Promoted With Lanthana: An Extent Of Reduction Study, Basseem B. Hallac, Jared C. Brown, Eli Stavitski, Roger G. Harrison, Morris D. Argyle

Faculty Publications

The extent of reduction of unsupported iron-based high-temperature water-gas shift catalysts with small (< 5 wt %) lanthana contents was studied using UV-visible spectroscopy. Temperature- programmed reduction measurements showed that lanthana content higher than 0.5 wt % increased the extent of reduction to metallic Fe, while 0.5 wt % of lanthana facilitated the reduction to Fe₃O₄. In situ measurements on the iron oxide catalysts using mass and UV-visible spectroscopies permitted the quantification of the extent of reduction under temperature-programmed reduction and high-temperature water-gas shift conditions. The oxidation states were successfully calibrated against normalized absorbance spectra of visible light using the Kubelka-Munk theory. The normalized absorbance relative to the fully oxidized Fe₂O₃ increased as the extent of reduction increased. XANES suggested that the average bulk iron oxidation state during the water-gas shift reaction was Fe^{+2.57 …}

Patent Keyword Extraction Algorithm Based On Distributed Representation For Patent Classification, Jie Hu, Shaobo Li, Yong Yao, Liya Yu, Guanci Yang, Jianjun Hu

Faculty Publications

Many text mining tasks such as text retrieval, text summarization, and text comparisons depend on the extraction of representative keywords from the main text. Most existing keyword extraction algorithms are based on discrete bag-of-words type of word representation of the text. In this paper, we propose a patent keyword extraction algorithm (PKEA) based on the distributed Skip-gram model for patent classification. We also develop a set of quantitative performance measures for keyword extraction evaluation based on information gain and cross-validation, based on Support Vector Machine (SVM) classification, which are valuable when human-annotated keywords are not available. We used a standard …

A Method For Characterizing Essential Tremor From The Shoulder To The Wrist, Daniel W. Geiger, Dennis Eggett, Steven K. Charles

Faculty Publications

Background

Despite the pervasive and devastating effect of Essential Tremor (ET), the distribution of ET throughout the upper limb is unknown. We developed a method for characterizing the distribution of ET and performed a preliminary characterization in a small number of subjects with ET.

Methods

Using orientation sensors and inverse kinematics, we measured tremor in each of the seven major degrees of freedom (DOF) from the shoulder to the wrist while ten patients with mild ET assumed 16 different postures. We described the tremor in each DOF in terms of power spectral density measures and investigated how tremor varied between …

3d Printed High Density, Reversible, Chip-To-Chip Microfluidic Interconnects, Hua Gong, Adam T. Woolley, Gregory P. Nordin

Faculty Publications

Our latest developments in miniaturizing 3D printed microfluidics [Gong et al., Lab Chip, 2016, 16, 2450; Gong et al., Lab Chip, 2017, 17, 2899] offer the opportunity to fabricate highly integrated chips that measure only a few mm on a side. For such small chips, an interconnection method is needed to provide the necessary world-to-chip reagent and pneumatic connections. In this paper, we introduce simple integrated microgaskets (SIMs) and controlled-compression integrated microgaskets (CCIMs) to connect a small device chip to a larger interface chip that implements world-to-chip connections. SIMs or CCIMs are directly 3D printed as part of the device …

Copper-Doped Lithium Triborate (Lib3o5) Crystals: A Photoluminescence, Thermoluminescence, And Electron Paramagnetic Resonance Study, Brant E. Kananen, John W. Mcclory, Nancy C. Giles, Larry E. Halliburton

Faculty Publications

When doped with copper ions, lithium borate materials are candidates for use in radiation dosimeters. Copper-doped lithium tetraborate (Li2B4O7) crystals have been widely studied, but little is known thus far about copper ions in lithium triborate (LiB3O5) crystals. In the present investigation, Cu+ ions (3d10) were diffused into an undoped LiB3O5 crystal at high temperature. These ions occupy both Li+ and interstitial positions in the crystal. A photoluminescence (PL) band peaking near 387 nm and a photoluminescence excitation (PLE) band peaking near 273 nm verify that a portion of these Cu+ ions are located at regular Li+ sites. After an …

Natural Sensations Evoked In Distal Extremities Using Surface Electrical Stimulation, Julia P. Slopsema, John M. Boss, Lane A. Heyboer, Carson M. Tobias, Brooke P. Draggoo, Kathleen E. Finn, Payton J. Hoff, Katharine H. Polasek

Faculty Publications

Background: Electrical stimulation is increasingly relevant in a variety of medical treatments. In this study, surface electrical stimulation was evaluated as a method to non-invasively target a neural function, specifically natural sensation in the distal limbs.

Method: Electrodes were placed over the median and ulnar nerves at the elbow and the common peroneal and lateral sural cutaneous nerves at the knee. Strength-duration curves for sensation were compared between nerves. The location, modality, and intensity of each sensation were also analyzed. In an effort to evoke natural sensations, several patterned waveforms were evaluated.

Results: Distal sensation was obtained in all but …

Metastable Ar(1s5) Density Dependence On Pressure And Argon-Helium Mixture In A High Pressure Radio Frequency Dielectric Barrier Discharge, Daniel J. Emmons, David E. Weeks, Ben Eshel, Glen P. Perram

Faculty Publications

Simulations of an α-mode radio frequency dielectric barrier discharge are performed for varying mixtures of argon and helium at pressures ranging from 200 to 500 Torr using both zero and one-dimensional models. Metastable densities are analyzed as a function of argon-helium mixture and pressure to determine the optimal conditions, maximizing metastable density for use in an optically pumped rare gas laser. Argon fractions corresponding to the peak metastable densities are found to be pressure dependent, shifting from approximately 15% Ar in He at 200 Torr to 10% at 500 Torr. A decrease in metastable density is observed as pressure …

Comparing Machine Learning And Decision Making Approaches To Forecast Long Lead Monthly Rainfall: The City Of Vancouver, Canada, Zahra Zahmatkesh, Erfan Goharian

Faculty Publications

Estimating maximum possible rainfall is of great value for flood prediction and protection, particularly for regions, such as Canada, where urban and fluvial floods from extreme rainfalls have been known to be a major concern. In this study, a methodology is proposed to forecast real-time rainfall (with one month lead time) using different number of spatial inputs with different orders of lags. For this purpose, two types of models are used. The first one is a machine learning data driven-based model, which uses a set of hydrologic variables as inputs, and the second one is an empirical-statistical model that employs …

Peri-Elastodynamic Simulations Of Guided Ultrasonic Lamb Waves In Smart Structure With Surface Mounted Pzt, Subir Patra, Hossain Ahmed, Sourav Banerjee

Faculty Publications

Peridynamic based elastodynamic computation tool named Peri-elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-elastodynamics method is not only …

A Hierarchical Feature Extraction Model For Multi-Label Mechanical Patent Classification, Jie Hu, Shaobo Li, Jianjun Hu, Guanci Yang

Faculty Publications

Various studies have focused on feature extraction methods for automatic patent classification in recent years. However, most of these approaches are based on the knowledge from experts in related domains. Here we propose a hierarchical feature extraction model (HFEM) for multi-label mechanical patent classification, which is able to capture both local features of phrases as well as global and temporal semantics. First, a n-gram feature extractor based on convolutional neural networks (CNNs) is designed to extract salient local lexical-level features. Next, a long dependency feature extraction model based on the bidirectional long–short-term memory (BiLSTM) neural network model is proposed to …

Effects Of Edge Inclination Angles On Whispering-Gallery Modes In Printable Wedge Microdisk Lasers, Cong Chen, Lei Wan, Hengky Chandrahalim

Faculty Publications

The ink-jet technique was developed to print the wedge polymer microdisk lasers. The characterization of these lasers was implemented using a free-space optics measurement setup. It was found that disks of larger edge inclination angles have a larger free spectral range (FSR) and a lower resonance wavelength difference between the fundamental transverse electric (TE) and transverse magnetic (TM) whispering-gallery modes (WGMs). This behavior was also confirmed with simulations based on the modified Oxborrow’s model with perfectly matched layers (PMLs), which was adopted to accurately calculate the eigenfrequencies, electric field distributions, and quality parameters of modes in the axisymmetric microdisk resonators. …

Investigation Into Reynolds Number Effects On A Biomimetic Flapping Wing, Daniel K. Hope, Anthony M. Deluca, Ryan P. O'Hara

Faculty Publications

This research investigated the behavior of a Manduca sexta inspired biomimetic wing as a function of Reynolds number by measuring the aerodynamic forces produced by varying the characteristic wing length and testing at air densities from atmospheric to near vacuum. A six degree of freedom balance was used to measure forces and moments, while high speed cameras were used to measure wing stroke angle. An in-house created graphical user interface was used to vary the voltage of the drive signal sent to the piezoelectric actuator which determined the wing stroke angle. The Air Force Institute of Technology baseline 50 mm …

A Survey Of Digital Systems Curriculum And Pedagogy In Electrical And Computer Engineering Programs, Hector A. Ochoa, Mukul V. Shirvaikar

Faculty Publications

Digital Systems is one of the basic foundational courses in Electrical and Computer Engineering. One of the challenges in designing and modifying the curriculum for the course is the fast pace of technology change in the area. TTL chips that were in vogue with students building physical circuits, have given way to new paradigms like FPGA based synthesis with hardware description languages such as VHDL. However, updating a course is not as simple as just changing the book, and changing the syllabus. A large amount of work needs to be done in terms of selecting the book that will accommodate …

Recommender Systems For Large-Scale Social Networks: A Review Of Challenges And Solutions, Magdalini Eirinaki, Jerry Gao, Iraklis Varlamis, Konstantinos Tserpes

Faculty Publications

Social networks have become very important for networking, communications, and content sharing. Social networking applications generate a huge amount of data on a daily basis and social networks constitute a growing field of research, because of the heterogeneity of data and structures formed in them, and their size and dynamics. When this wealth of data is leveraged by recommender systems, the resulting coupling can help address interesting problems related to social engagement, member recruitment, and friend recommendations.In this work we review the various facets of large-scale social recommender systems, summarizing the challenges and interesting problems and discussing some of the …

A Data-Driven Approach For Detecting Autism Spectrum Disorders, Manika Kapoor, David Anastasiu

Faculty Publications

No abstract provided.

The U.S. Nuclear Waste Impasse: Transportation Implications, Robin M. Rotman, Michael F. Mcbride

Faculty Publications

For several years there has been an impasse, in the political branches, over how to make progress on dealing with the intractable problem of nuclear waste disposal in the United States. Currently, over 120 sites, spread across 39 states, host commercial spent fuel—many of these sites are former reactors that have become de facto interim nuclear waste storage sites, pending a permanent solution. Transportation considerations are central in this discussion. With the potential for Congress to make progress on this issue following the 2018 midterm elections, this article reviews the potential paths forward and considers possible implications for the transportation …

Hydrothermal Carbonization: Modeling, Final Properties Design And Applications: A Review, Silvia Román, Judy Libra, Nicole Berge, Eduardo Sabio, Kyoung Ro, Liang Li, Beatriz Ledesma, Andrés Alvarez, Sunyoung Bae

Faculty Publications

Active research on biomass hydrothermal carbonization (HTC) continues to demonstrate its advantages over other thermochemical processes, in particular the interesting benefits that are associated with carbonaceous solid products, called hydrochar (HC). The areas of applications of HC range from biofuel to doped porous material for adsorption, energy storage, and catalysis. At the same time, intensive research has been aimed at better elucidating the process mechanisms and kinetics, and how the experimental variables (temperature, time, biomass load, feedstock composition, as well as their interactions) affect the distribution between phases and their composition. This review provides an analysis of the state of …

Engineering Identity Development: A Review Of Higher Education Literature, Sarah L. Rodriguez, Charles Lu, Morgan Bartlett

Faculty Publications

The purpose of this systematic literature review was to appraise and synthesize the current scholarship pertaining to engineering identity development within the higher education context and create recommendations for future scholarship within engineering education. A review of the literature concluded that research on engineering identity development has increased over the past ten years, has been conducted primarily with qualitative methods, and has been primarily limited to academic communities focused on mathematics, science, and engineering education. In addition, current scholarship reflected that most of the work in this area has focused on the learning contexts and experiences of women and underrepresented …

A Novel Supercritical Co2-Based Decellularization Method For Maintaining Scaffold Hydration And Mechanical Properties, Michael A. Matthews, Tarek Shazly, Rachel M. Handleton, Dominic M. Casali

Faculty Publications

Decellularized tissues are commonly utilized as tissue engineering scaffolds. Decellularization by extended exposure to aqueous detergents can damage the microstructure or deposit cytotoxic residue. Supercritical carbon dioxide (scCO2) has been proposed for decellularization, but reportedly causes dehydration and scaffold embrittlement.

Presented herein is a novel decellularization method that preserves matrix hydration state and mechanical properties. Over 97% of the water in porcine aorta is maintained by presaturating scCO2 with water; however, complete decellularization was not attained by any process utilizing only scCO2. Instead, a novel hybrid method is presented that combines a brief (48 h) exposure of tissue to aqueous …

An Origami-Based Thickness-Accommodating Bistable Mechanism In Monolithic Thick-Sheet Materials, Larry L. Howell, Spencer P. Magleby, Nathan A. Pehrson

Faculty Publications

Origami-based mechanisms can provide useful capabilities in folding large structures to stow in small volumes. However, when using monolithic thick-sheet materials for these types of mechanisms, accommodating the thickness proves challenging. One approach to solve this is to create compliant mechanisms along the fold lines that inherently store energy when actuated and causes the mechanism to tend toward its low energy state. This tendency can be used to create bistable states. We outline a method to use this stored energy to achieve bistable states and name the resulting mechanism an origami-based “Thickness-accommodating bistable interior vertex” (TABIV) in monolithic thick-sheet materials. …