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Faculty Publications

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Full-Text Articles in Engineering

Dynamic Simulation Of A Novel Nuclear Hybrid Energy System With Large-Scale Hydrogen Storage In An Underground Salt Cavern, An Ho, Kasra Mohammadi, Matthew Memmott, John Hedengren, Kody Powell Sep 2021

Dynamic Simulation Of A Novel Nuclear Hybrid Energy System With Large-Scale Hydrogen Storage In An Underground Salt Cavern, An Ho, Kasra Mohammadi, Matthew Memmott, John Hedengren, Kody Powell

Faculty Publications

In this study, a nuclear hybrid energy system (NHES) with large-scale hydrogen storage integrated with a gas turbine cycle is proposed as a flexible system for load following. The proposed system consists of a nuclear reactor, a steam Rankine cycle, a hydrogen electrolyzer, a storage system for hydrogen in an underground salt cavern, and a Brayton cycle that uses hydrogen as fuel to generate additional electricity to meet peak demand. A dynamic mathematical model is developed for each subsystem of the NHES. To evaluate the potential benefits of the system, a one-year study is conducted, using scaled grid demand data …

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Electroanalytical Measurements Of Oxide Ions In Molten Cacl2 On W Electrode, Devin Rappleye, Chao Zhang, Art Nelson, Scott Simpson, Michael Simpson Sep 2021

Electroanalytical Measurements Of Oxide Ions In Molten Cacl2 On W Electrode, Devin Rappleye, Chao Zhang, Art Nelson, Scott Simpson, Michael Simpson

Faculty Publications

The electrochemical interaction of oxide ions with tungsten electrodes in molten calcium chloride (CaCl2) was analyzed by combining electroanalytical techniques with X-ray photoelectron spectroscopy. During a cyclic voltammetry (CV) scan, the oxide ions appear to interact with the tungsten working electrode via a multi-step oxidation and reduction process. The overall redox peaks behave reversibly up to 750 mV/s. This electrochemical process enables the oxide ion concentration to be correlated to CV oxidation peaks. The resulting correlation agrees well (8.8% difference) with back titration measurements and can be used to monitor oxide content in the salt in real-time during …

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Fourth-Order Adjoint Sensitivity And Uncertainty Analysis Of An Oecd/Nea Reactor Physics Benchmark: I. Computed Sensitivities, Ruixian Fang, Dan Gabriel Cacuci Sep 2021

Fourth-Order Adjoint Sensitivity And Uncertainty Analysis Of An Oecd/Nea Reactor Physics Benchmark: I. Computed Sensitivities, Ruixian Fang, Dan Gabriel Cacuci

Faculty Publications

This work extends the investigation of higher-order sensitivity and uncertainty analysis from 3rd-order to 4th-order for a polyethylene-reflected plutonium (PERP) OECD/NEA reactor physics benchmark. Specifically, by applying the 4th-order comprehensive adjoint sensitivity analysis methodology (4th-CASAM) to the PERP benchmark, this work presents the numerical results of the most important 4th-order sensitivities of the benchmark’s total leakage response with respect to the benchmark’s 180 microscopic total cross sections, which includes 180 4th-order unmixed sensitivities and 360 4th-order mixed sensitivities corresponding to the largest 3rd-order ones. The numerical results obtained in this work reveal that the number of 4th-order relative sensitivities that …

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Simulation Modeling Of A Photovoltaic-Green Roof System For Energy Cost Reduction Of A Building: Texas Case Study, Sojung Kim, Burchan Aydin, Sumin Kim Sep 2021

Simulation Modeling Of A Photovoltaic-Green Roof System For Energy Cost Reduction Of A Building: Texas Case Study, Sojung Kim, Burchan Aydin, Sumin Kim

Faculty Publications

This study aims at introducing a modeling and simulation approach for a green roof system which can reduce energy cost of a building exposed to high temperatures throughout the summer season. First, to understand thermal impact of a green roof system on a building surface, a field-based study has been conducted in Commerce, Texas, U.S., where the average maximum temperature in summer is 104 F (40 C). Two types of analyses were conducted: (1) comparison of temperature between different plant type via Analysis of variance (ANOVA) and (2) polynomial regression analysis to develop thermal impact estimation model based on air …

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Vacuum Infusion Of Composites: Durability Of Hybrid Large Area Additive Tooling For Vacuum Infusion Of Composites, Nathan Northrup, Jason Weaver, Andy R. George Sep 2021

Vacuum Infusion Of Composites: Durability Of Hybrid Large Area Additive Tooling For Vacuum Infusion Of Composites, Nathan Northrup, Jason Weaver, Andy R. George

Faculty Publications

The durability of a hybrid large area additively manufactured fiberglass ABS mold for vacuum infusion of composites was evaluated. The validation was done by designing and fabricating a mold for a custom test artifact and analyzing the surface geometry over the course of multiple infusions until tool failure. After printing and machining, the mold required a sealer to maintain vacuum integrity. The mold was able to produce 10 parts successfully before the sealed tool surface began to tangibly roughen, resulting in increased difficulty of demolding and a rougher surface finish. After the 14th infusion, the part required destructive force to …

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Bright And Blind Spots Of Water Research In Latin America And The Caribbean, Alyssa J. Devincentis, Hervé Guillon, Romina Díaz Gómez, Noelle K. Patterson, Francine Van Den Brandeler, Srthur Koehl, Pablo Ortiz-Partida, Laura E. Garza-Díaz, Jennifer Gamez-Rodríguez, Erfan Goharian, Samuel Sandoval Solis Aug 2021

Bright And Blind Spots Of Water Research In Latin America And The Caribbean, Alyssa J. Devincentis, Hervé Guillon, Romina Díaz Gómez, Noelle K. Patterson, Francine Van Den Brandeler, Srthur Koehl, Pablo Ortiz-Partida, Laura E. Garza-Díaz, Jennifer Gamez-Rodríguez, Erfan Goharian, Samuel Sandoval Solis

Faculty Publications

Water resources management in Latin America and the Caribbean is particularly threatened by climatic, economic, and political pressures. To assess the region's ability to manage water resources, we conducted an unprecedented literature review of over 20 000 multilingual research articles using machine learning and an understanding of the socio-hydrologic landscape. Results reveal that the region's vulnerability to water-related stresses, and drivers such as climate change, is compounded by research blind spots in niche topics (reservoirs and risk assessment) and subregions (Caribbean nations), as well as by its reliance on an individual country (Brazil). A regional bright spot, Brazil, produces well-rounded …

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Merging Of Horizontally And Vertically Separated Small-Scale Buoyant Flames, Thomas H. Fletcher, Denver Haycock, Seth Tollefsen, David Lignell Aug 2021

Merging Of Horizontally And Vertically Separated Small-Scale Buoyant Flames, Thomas H. Fletcher, Denver Haycock, Seth Tollefsen, David Lignell

Faculty Publications

The purpose of this study was to investigate the merging behavior of small-scale buoyant flames that might be representative of flames from a leaf in a shrub. Zirconia felt pads soaked in n-heptane were suspended on thin rods and spaced both horizontally and vertically. Time-dependent video images from flames from two-pad and three-pad configurations were analyzed to determine merging probability, combined flame characteristics (height, area, and width), and changes in burn time. Correlations of these combined flame characteristics were developed based on horizontal and vertical spacing between the pads. Merging probability correlated with an exponential function that was quadratic in …

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Electrochemical Micro-Aptasensors For Exosome Detection Based On Hybridization Chain Reaction Amplification, Wenfen Zhang, Zhenhua Tian, Shujie Yang, Joseph Rich, Shuaiguo Zhao, Mikael Klingeborn, Po-Hsun Huang, Zhishang Li, Alexander Stout, Quinn Murphy, Edward Patz, Shusheng Zhang, Guozhen Liu, Tony Jun Huang Aug 2021

Electrochemical Micro-Aptasensors For Exosome Detection Based On Hybridization Chain Reaction Amplification, Wenfen Zhang, Zhenhua Tian, Shujie Yang, Joseph Rich, Shuaiguo Zhao, Mikael Klingeborn, Po-Hsun Huang, Zhishang Li, Alexander Stout, Quinn Murphy, Edward Patz, Shusheng Zhang, Guozhen Liu, Tony Jun Huang

Faculty Publications

Exosomes are cell-derived nanovesicles that have recently gained popularity as potential biomarkers in liquid biopsies due to the large amounts of molecular cargo they carry, such as nucleic acids and proteins. However, most existing exosome-based analytical sensing methods struggle to achieve high sensitivity and high selectivity simultaneously. In this work, we present an electrochemical micro-aptasensor for the highly sensitive detection of exosomes by integrating a micropatterned electrochemical aptasensor and a hybridization chain reaction (HCR) signal amplification method. Specifically, exosomes are enriched on CD63 aptamer-functionalized electrodes and then recognized by HCR products with avidin-horseradish peroxidase (HRP) attached using EpCAM aptamers as …

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Analysis Of The Effects Of Spatiotemporal Demand Data Aggregation Methods On Distance And Volume Errors, Zachary Hornberger, Bruce A. Cox, Raymond R. Hill Aug 2021

Analysis Of The Effects Of Spatiotemporal Demand Data Aggregation Methods On Distance And Volume Errors, Zachary Hornberger, Bruce A. Cox, Raymond R. Hill

Faculty Publications

Purpose — Large/stochastic spatiotemporal demand data sets can prove intractable for location optimization problems, motivating the need for aggregation. However, demand aggregation induces errors. Significant theoretical research has been performed related to the modifiable areal unit problem and the zone definition problem. Minimal research has been accomplished related to the specific issues inherent to spatiotemporal demand data, such as search and rescue (SAR) data. This study provides a quantitative comparison of various aggregation methodologies and their relation to distance and volume based aggregation errors. Design/methodology/approach — This paper introduces and applies a framework for comparing both deterministic and stochastic aggregation …

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Augmenting The Space Domain Awareness Ground Architecture Via Decision Analysis And Multi-Objective Optimization, Albert R. Vasso, Richard G. Cobb, John M. Colombi, Bryan D. Little, David R. Meyer Aug 2021

Augmenting The Space Domain Awareness Ground Architecture Via Decision Analysis And Multi-Objective Optimization, Albert R. Vasso, Richard G. Cobb, John M. Colombi, Bryan D. Little, David R. Meyer

Faculty Publications

Purpose — The US Government is challenged to maintain pace as the world’s de facto provider of space object cataloging data. Augmenting capabilities with nontraditional sensors present an expeditious and low-cost improvement. However, the large tradespace and unexplored system of systems performance requirements pose a challenge to successful capitalization. This paper aims to better define and assess the utility of augmentation via a multi-disiplinary study. Design/methodology/approach — Hypothetical telescope architectures are modeled and simulated on two separate days, then evaluated against performance measures and constraints using multi-objective optimization in a heuristic algorithm. Decision analysis and Pareto optimality identifies a set …

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Rapid Computation Of Effective Conductivity Of 2d Composites By Equivalent Circuit And Spectral Methods., Ben J. Ransom, Dean R. Wheeler Aug 2021

Rapid Computation Of Effective Conductivity Of 2d Composites By Equivalent Circuit And Spectral Methods., Ben J. Ransom, Dean R. Wheeler

Faculty Publications

This work presents models for homogenizing or finding the effective transport or mechanical properties of microscale composites formed from highly contrasting phases described on a grid. The methods developed here are intended for engineering applications where speed and geometrical flexibility are a premium. A canonical case that is mathematically challenging and yet can be applied to many realistic materials is a 4-phase 2-dimensional periodic checkerboard or tiling. While analytic solutions for calculating effective properties exist for some cases, versatile methods are needed to handle anisotropic and non-square grids. A reinterpretation and extension of an existing analytic solution that utilizes equivalent …

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High-Throughput Discovery Of Novel Cubic Crystal Materials Using Deep Generative Neural Networks, Yong Zhao, Mohammed Al-Fahdi, Ming Hu, Edirisuriya M.D. Siriwardane, Yuqi Song, Alireza Nasiri, Jianjun Hu Aug 2021

High-Throughput Discovery Of Novel Cubic Crystal Materials Using Deep Generative Neural Networks, Yong Zhao, Mohammed Al-Fahdi, Ming Hu, Edirisuriya M.D. Siriwardane, Yuqi Song, Alireza Nasiri, Jianjun Hu

Faculty Publications

High-throughput screening has become one of the major strategies for the discovery of novel functional materials. However, its effectiveness is severely limited by the lack of sufficient and diverse materials in current materials repositories such as the open quantum materials database (OQMD). Recent progress in deep learning have enabled generative strategies that learn implicit chemical rules for creating hypothetical materials with new compositions and structures. However, current materials generative models have difficulty in generating structurally diverse, chemically valid, and stable materials. Here we propose CubicGAN, a generative adversarial network (GAN) based deep neural network model for large scale generative design …

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The Effects Of Ceria Loading On Three-Way Catalysts For Passive Scr Operation, Calvin R. Thomas, Josh A. Pihl, Vitaly Y. Prikhodko, Michelle K. Kidder, Jochen A. Lauterbach, Todd J. Toops Aug 2021

The Effects Of Ceria Loading On Three-Way Catalysts For Passive Scr Operation, Calvin R. Thomas, Josh A. Pihl, Vitaly Y. Prikhodko, Michelle K. Kidder, Jochen A. Lauterbach, Todd J. Toops

Faculty Publications

Passive SCR systems, which employ both a three-way catalyst and SCR catalyst, are effective for the reduction of nitrogen oxide (NOx) emissions from lean burn gasoline engines. However, questions remain regarding the effect of three-way catalyst formulations on their performance in these systems. Here, Pd/CeOx/Al2O3 catalysts with variable CeOx loading were synthesized, characterized, and evaluated to determine the effects of CeOx on catalyst performance. While a small amount of ceria was beneficial for promoting essential reactions, excess ceria was detrimental due to the increase in oxygen storage capacity. Additionally, insights into potential reaction pathways for NH3 production were determined.

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The Effects Of Ceria Loading On Three-Way Catalysts For Passive Scr Operation, Calvin R. Thomas, Josh A. Pihl, Vitaly Y. Prikhodko, Michelle K. Kidder, Jochen A. Lauterbach, Todd J. Toops Aug 2021

The Effects Of Ceria Loading On Three-Way Catalysts For Passive Scr Operation, Calvin R. Thomas, Josh A. Pihl, Vitaly Y. Prikhodko, Michelle K. Kidder, Jochen A. Lauterbach, Todd J. Toops

Faculty Publications

Passive SCR systems, which employ both a three-way catalyst and SCR catalyst, are effective for the reduction of nitrogen oxide (NOx) emissions from lean burn gasoline engines. However, questions remain regarding the effect of three-way catalyst formulations on their performance in these systems. Here, Pd/CeOx/Al2O3 catalysts with variable CeOx loading were synthesized, characterized, and evaluated to determine the effects of CeOx on catalyst performance. While a small amount of ceria was beneficial for promoting essential reactions, excess ceria was detrimental due to the increase in oxygen storage capacity. Additionally, insights into potential reaction pathways for NH3 production were determined.

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Mixing Optimization With Inward Flow Configuration Contra-Rotating Impeller, Baffle-Free Tank, P. Satjaritanun, J. R. Regalbuto, J. A. Regalbuto, N. Tippayawong, Sirivatch Shimpalee Aug 2021

Mixing Optimization With Inward Flow Configuration Contra-Rotating Impeller, Baffle-Free Tank, P. Satjaritanun, J. R. Regalbuto, J. A. Regalbuto, N. Tippayawong, Sirivatch Shimpalee

Faculty Publications

In this study, pitched-blade, contra-rotating impeller, baffle-free tank with opposing inward flow is optimized using various designs of mixers derived from the Taguchi method. Mixing efficiency and torque are used to find the optimal design for the different specific gravities of solid particles employing in both experiments and CFD simulations. The analysis of signal-to-noise ratio shows that the impeller clearance and diameter are significant factors on the fluid flow and thus the mixing efficiency. In this study, 27 cases were studied to determine and report the optimal design parameters. A combination of CFD simulation with a strong design of experiment …

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Production Of Pure Vanadium: Industry Review And Feasibility Study Of Electron Beam Melt Refining Of V–Al Alloys, Devin Rappleye, Rob Haun Jul 2021

Production Of Pure Vanadium: Industry Review And Feasibility Study Of Electron Beam Melt Refining Of V–Al Alloys, Devin Rappleye, Rob Haun

Faculty Publications

The vanadium industry has experienced significant change over the last two decades with the emergence of vanadium redox flow batteries for grid-level energy storage, the growing demand for high-strength steel, and the selection of vanadium as a critical material in multiple countries. This review presents the status of the vanadium industry examining production processes and detailing facilities. The available information for each producer is presented including vanadium products and capacity. The production of pure vanadium is identified as a potential vulnerability for some nations where vanadium metal is needed in small, yet strategic, applications and globally only two producers of …

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The Impact Of Micro Porous Layer On Liquid Water Evolution Inside Pemfc Using Lattice Boltzmann Method, Mitchell Sepe, P. Satjaritanun, I. V. Zenyuk, N. Tippayawong, Sirivatch Shimpalee Jul 2021

The Impact Of Micro Porous Layer On Liquid Water Evolution Inside Pemfc Using Lattice Boltzmann Method, Mitchell Sepe, P. Satjaritanun, I. V. Zenyuk, N. Tippayawong, Sirivatch Shimpalee

Faculty Publications

Proton exchange membrane fuel cells (PEMFCs) require a gas diffusion layer to aid in fuel transport to the catalyst sites. A microporous layer (MPL) is often added to the GDL to improve liquid saturation inside gas diffusion media. In this work, the lattice Boltzmann method was applied to four GDL samples with the addition of an MPL. Three injection orientations were used to study liquid evolution through the samples. Each orientation used four different injection pressures, ranging from 5,000 Pa to 8,000 Pa. Saturation data for GDL samples with and without an MPL were compared. Results showed that when adding …

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Investigation And Statistical Modeling Of The Mechanical Properties Of Additively Manufactured Lattices, Derek G. Spear, Anthony N. Palazotto Jul 2021

Investigation And Statistical Modeling Of The Mechanical Properties Of Additively Manufactured Lattices, Derek G. Spear, Anthony N. Palazotto

Faculty Publications

This paper describes the background, test methodology, and experimental results associated with the testing and analysis of quasi-static compression testing of additively manufactured open-cell lattice structures. The study aims to examine the effect of lattice topology, cell size, cell density, and surface thickness on the mechanical properties of lattice structures. Three lattice designs were chosen, the Diamond, I-WP, and Primitive Triply Periodic Minimal Surfaces (TPMSs). Uniaxial compression tests were conducted for every combination of the three lattice designs, three cell sizes, three cell densities, and three surface thicknesses. In order to perform an efficient experiment and gain the most information …

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Nanoparticles For Targeted Drug Delivery To Cancer Stem Cells: A Review Of Recent Advances, Yavuz Nuri Ertas, Keyvan Abedi Dorcheh, Ali Akbari, Esmaiel Jabbari Jul 2021

Nanoparticles For Targeted Drug Delivery To Cancer Stem Cells: A Review Of Recent Advances, Yavuz Nuri Ertas, Keyvan Abedi Dorcheh, Ali Akbari, Esmaiel Jabbari

Faculty Publications

Cancer stem cells (CSCs) are a subpopulation of cells that can initiate, self-renew, and sustain tumor growth. CSCs are responsible for tumor metastasis, recurrence, and drug resistance in cancer therapy. CSCs reside within a niche maintained by multiple unique factors in the microenvironment. These factors include hypoxia, excessive levels of angiogenesis, a change of mitochondrial activity from aerobic aspiration to aerobic glycolysis, an upregulated expression of CSC biomarkers and stem cell signaling, and an elevated synthesis of the cytochromes P450 family of enzymes responsible for drug clearance. Antibodies and ligands targeting the unique factors that maintain the niche are utilized …

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High-Throughput Computation Of New Carbon Allotropes With Diverse Hybridization And Ultrahigh Hardness, Mohammed Al-Fahdi, Alejandro Rodriguez, Tao Ouyang, Ming Hu Jul 2021

High-Throughput Computation Of New Carbon Allotropes With Diverse Hybridization And Ultrahigh Hardness, Mohammed Al-Fahdi, Alejandro Rodriguez, Tao Ouyang, Ming Hu

Faculty Publications

The discovery of new carbon allotropes with different building blocks and crystal symmetries has long been of great interest to broad materials science fields. Herein, we report several hundred new carbon allotropes predicted by the state-of-the-art RG2 code and first-principles calculations. The types of new carbon allotropes that were identified in this work span pure sp2 , hybrid sp2/sp3 , and pure sp3 C–C bonding. All structures were globally optimized at the first-principles level. The thermodynamic stability of some selected carbon allotropes was further validated by computing their phonon dispersions. The predicted carbon allotropes …

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Nanoparticles For Targeted Drug Delivery To Cancer Stem Cells: A Review Of Recent Advances, Yavuz Nuri Ertas, Keyvan Abedu Dorcheh, Ali Akbari, Esmaiel Jabbari Jul 2021

Nanoparticles For Targeted Drug Delivery To Cancer Stem Cells: A Review Of Recent Advances, Yavuz Nuri Ertas, Keyvan Abedu Dorcheh, Ali Akbari, Esmaiel Jabbari

Faculty Publications

Cancer stem cells (CSCs) are a subpopulation of cells that can initiate, self-renew, and sustain tumor growth. CSCs are responsible for tumor metastasis, recurrence, and drug resistance in cancer therapy. CSCs reside within a niche maintained by multiple unique factors in the microenvironment. These factors include hypoxia, excessive levels of angiogenesis, a change of mitochondrial activity from aerobic aspiration to aerobic glycolysis, an upregulated expression of CSC biomarkers and stem cell signaling, and an elevated synthesis of the cytochromes P450 family of enzymes responsible for drug clearance. Antibodies and ligands targeting the unique factors that maintain the niche are utilized …

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Using Cellular Automata Approach To Optimize The Hydropower Reservoir Operation Of Folsom Dam, Erfan Goharian, Mohammed Azizipour, Samuel Sandoval-Solis, Graham Fogg Jul 2021

Using Cellular Automata Approach To Optimize The Hydropower Reservoir Operation Of Folsom Dam, Erfan Goharian, Mohammed Azizipour, Samuel Sandoval-Solis, Graham Fogg

Faculty Publications

While hydropower in California is one the main sources of renewable energy, population growth has continuously increased demand for energy. In addition, recent droughts reduced the amount of available water behind the hydropower dams to provide the water head needed to run the turbines in hydropower plants. A more sustainable alternative, instead of developing new infrastructure, is to enhance the daily operation of reservoirs to support hydropower generation. This study suggests a new optimal operation policy for Folsom Reservoir in California and hydropower plants, which maximizes hydropower generation and reduces flood risk. This study demonstrates the application of the cellular …

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A Meta-Level Approach For Multilingual Taint Analysis, Damian Lyons, Dino Becaj Jul 2021

A Meta-Level Approach For Multilingual Taint Analysis, Damian Lyons, Dino Becaj

Faculty Publications

It is increasingly common for software developers to leverage the features and ease-of-use of different languages in building software systems. Nonetheless, interaction between different languages has proven to be a source of software engineering concerns. Existing static analysis tools handle the software engineering concerns of monolingual software but there is little general work for multilingual systems despite the increasing visibility of these systems. While recent work in this area has greatly extended the scope of multilingual static analysis systems, the focus has still been on a primary, host language interacting with subsidiary, guest language functions. In this paper we propose …

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Wall Detection Via Imu Data Classification In Autonomous Quadcopters, Jason Hughes, Damian Lyons Jul 2021

Wall Detection Via Imu Data Classification In Autonomous Quadcopters, Jason Hughes, Damian Lyons

Faculty Publications

Abstract—An autonomous drone flying near obstacles needs to be able to detect and avoid the obstacles or it will collide with them. In prior work, drones can detect and avoid walls using data from camera, ultrasonic or laser sensors mounted either on the drone or in the environment. It is not always possible to instrument the environment, and sensors added to the drone consume payload and power - both of which are constrained for drones. This paper studies how data mining classification techniques can be used to predict where an obstacle is in relation to the drone based only on …

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Influencing Perceptions Of Stem Through The Best Stem Books List, Scott Bartholomew, Alexia Seymour Jul 2021

Influencing Perceptions Of Stem Through The Best Stem Books List, Scott Bartholomew, Alexia Seymour

Faculty Publications

One day, while discussing engineering and science as potential career options with a female student, we opened a search engine and typed in “engineer” and “scientist.” However, on the first pages of image results, only one female appeared for engineering and only a few females appeared for “scientist” (see Figure 1). This disparity was disturbing—if this student never saw another person like her filling careers in STEM fields, would she ever “picture herself” in those fields?

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Uranium Integral Fission Product Yields For A Spectrally-Shaped 14.1 Mev Neutron Source At The National Ignition Facility, Nicholas J. Quartemont, N. Gharibyan, K. Moody, James E. Bevins Jul 2021

Uranium Integral Fission Product Yields For A Spectrally-Shaped 14.1 Mev Neutron Source At The National Ignition Facility, Nicholas J. Quartemont, N. Gharibyan, K. Moody, James E. Bevins

Faculty Publications

This paper describes the experimental results for an energy tuning assembly created to modify the National Ignition Facility deuterium–tritium fusion neutron source into a notional thermonuclear and prompt fission neutron spectrum, which has applications in integral measurements, nuclear data benchmarks, and radiation effects on microelectronics. The Monte Carlo neutron transport utilized MCNP5 to estimate the ETA-modified fluence using the ENDF-B/VIII.0 and IRDFF-II continuous energy nuclear data libraries, and SCALE Sampler was used to estimate the systematic nuclear data covariance using ENDF-B/VII.1 and IRDFF-II in a 252-group structure. The experiment fielded eight activation foils and a highly enriched uranium sample. This …

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On Using The Bmcsl Equation Of State To Renormalize The Onsager Theory Approach To Modeling Hard Prolate Spheroidal Liquid Crystal Mixtures, Donya Ohadi, David S. Corti, Mark J. Uline Jun 2021

On Using The Bmcsl Equation Of State To Renormalize The Onsager Theory Approach To Modeling Hard Prolate Spheroidal Liquid Crystal Mixtures, Donya Ohadi, David S. Corti, Mark J. Uline

Faculty Publications

Modifications to the traditional Onsager theory for modeling isotropic–nematic phase transitions in hard prolate spheroidal systems are presented. Pure component systems are used to identify the need to update the Lee–Parsons resummation term. The Lee–Parsons resummation term uses the Carnahan–Starling equation of state to approximate higher-order virial coefficients beyond the second virial coefficient employed in Onsager’s original theoretical approach. As more exact ways of calculating the excluded volume of two hard prolate spheroids of a given orientation are used, the division of the excluded volume by eight, which is an empirical correction used in the original Lee–Parsons resummation term, must …

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Crack-Length Estimation For Structural Health Monitoring Using The High-Frequency Resonances Excited By The Energy Release During Fatigue-Crack Growth, Joseph Roshan, Hanfei Mei, Asaad Migot, Victor Giurgiutiu Jun 2021

Crack-Length Estimation For Structural Health Monitoring Using The High-Frequency Resonances Excited By The Energy Release During Fatigue-Crack Growth, Joseph Roshan, Hanfei Mei, Asaad Migot, Victor Giurgiutiu

Faculty Publications

Acoustic waves are widely used in structural health monitoring (SHM) for detecting fatigue cracking. The strain energy released when a fatigue crack advances has the effect of exciting acoustic waves, which travel through the structures and are picked up by the sensors. Piezoelectric wafer active sensors (PWAS) can effectively sense acoustic waves due to fatigue-crack growth. Conventional acoustic-wave passive SHM, which relies on counting the number of acoustic events, cannot precisely estimate the crack length. In the present research, a novel method for estimating the crack length was proposed based on the high-frequency resonances excited in the crack by the …

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Fabrication And Characterization Of Non-Equilibrium Plasma-Treated Pvdf Nanofiber Membrane-Based Sensors, Quazi Nahida Sultana, Mujibur Khan, Rajib Mahamud, Mohammadsadegh Saadatzi, Papia Sultana, Tanvir Farouk, Rafael Quirino, Sourav Banerjee Jun 2021

Fabrication And Characterization Of Non-Equilibrium Plasma-Treated Pvdf Nanofiber Membrane-Based Sensors, Quazi Nahida Sultana, Mujibur Khan, Rajib Mahamud, Mohammadsadegh Saadatzi, Papia Sultana, Tanvir Farouk, Rafael Quirino, Sourav Banerjee

Faculty Publications

The effect of a self-pulsing non-equilibrium plasma discharge on piezoelectric PVDF nanofiber membrane was investigated. The plasma discharge was generated in air with a DC power source, with a discharge current of 0.012 mA, a nominal interelectrode separation of 1 mm, and discharge voltage of ~970 V. In a continuous fabrication process, the electrospinning method was used to generate thin nanofiber membrane with a flow rate of 0.7–1 mL h−1 and 25–27 kV voltage to obtain the nanofiber with high sensitivity and a higher degree of alignment and uniformity over a larger area. Plasma treatment was applied on both single …

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Development Of Catalytic Combustion And Co2 Capture And Conversion Technology, Zhibin Yang, Ze Lei, Xingyu Xiong, Yiqian Jin, Kui Jiao, Fanglin Chen, Suping Peng Jun 2021

Development Of Catalytic Combustion And Co2 Capture And Conversion Technology, Zhibin Yang, Ze Lei, Xingyu Xiong, Yiqian Jin, Kui Jiao, Fanglin Chen, Suping Peng

Faculty Publications

Changes are needed to improve the efficiency and lower the CO2 emissions of traditional coal-fired power generation, which is the main source of global CO2 emissions. The integrated gasification fuel cell (IGFC) process, which combines coal gasification and high-temperature fuel cells, was proposed in 2017 to improve the efficiency of coal-based power generation and reduce CO2 emissions. Supported by the National Key R&D Program of China, the IGFC for nearzero CO2 emissions program was enacted with the goal of achieving near-zero CO2 emissions based on (1) catalytic combustion of the flue gas from solid oxide …

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