Engineering Commons^™

The Effect Of Tantalum Incorporation On The Physical And Chemical Properties Of Ternary Silicon–Calcium–Phosphorous Mesoporous Bioactive Glasses, Andrew Mendonca, Md Saidur Rahman, Adel Alhalawani, Omar Rodriguez, Reid C. Gallant, Heyu Ni, Owen M. Clarkin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Synthesis and characterization of the first mesoporous bioactive glasses (MBGs) containing tantalum are reported here, along with their potential application as hemostats. Silica MBGs were synthesized using with the molar composition of (80-x)% Si, 15% Ca, 5% P, and x% Ta. It was found that incorporation of >1 mol % Ta into the MBGs changes their physical and chemical properties. Increasing Ta content from 0 to 10 mol % causes a decrease in the surface area and pore volume of ~20 and ~35%, respectively. This is due to the increase in nonbridging oxygens and mismatch of thermal expansion coefficient which …

Hydrothermal Preparation Of Palladium Supported On Magnetite For Catalysis Applications, Hany A. Elazab, S. A. Hassan, M. A. Radwan, M. A. Sadek

Chemical and Biochemical Engineering Faculty Research & Creative Works

Herein, versatile, and reproducible method to prepare Pd/Fe₃O₄ via hydrothermal synthesis. The vital role of this catalyst is in its potential use in CO oxidation catalysis. The Pd/Fe₃O₄ shows a distinctive activity. TEM images confirmed that Pd nanoparticles of 8-12 nm have a well dispersion on the surface of magnetite (Fe₃O₄). Moreover, the prepared catalyst is recycled with remarkable catalytic activity. This outstanding activity is mainly a direct result of the strong metal-support interaction. The defect sites in the reduced iron oxide act as nucleation centers that enable anchoring of …

Three-Dimensional Rotation Of Paramagnetic And Ferromagnetic Prolate Spheroids In Simple Shear And Uniform Magnetic Field, Christopher A. Sobecki, Yanzhi Zhang, Cheng Wang

Mathematics and Statistics Faculty Research & Creative Works

We examine a time-dependent, three-dimensional rotation of magnetic ellipsoidal particles in a two-dimensional, simple shear flow and a uniform magnetic field. We consider that the particles have paramagnetic and ferromagnetic properties, and we compare their rotational dynamics due to the strengths and directions of the applied uniform magnetic field. We determine the critical magnetic field strength that can pin the particles' rotations. Above the critical field strength, the particles' stable steady angles were determined. In a weak magnetic regime (below the critical field strength), a paramagnetic particle's polar angle will oscillate toward the magnetic field plane while its azimuthal angle …

Stochastic Partial Inductance For The Power Integrity Analysis By Polynomial Chaos Expansion, Haimi Qiu, Lijun Jiang, Albert Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Partial element equivalent circuit (PEEC) model has attracted great interests to overcome challenges in the power integrity analysis. However, the increasing miniaturization in electronics makes the uncertainty effect an ever more central issue to accurately estimate the inductance in the power distribution networks (PDNs) of high-speed PCBs. In this paper, we propose a stochastic partial inductance modeling approach to quantify the stochastic inductance. Specifically, the deterministic partial inductance is re-formulated using the polynomial chaos expansion. Following the Galerkin projection and polynomial orthogonality, stochastic partial inductance is represented by polynomial bases, which significantly reduces the complexity of the system and leads …

Impulse Response For Full Wave Peec Models Avoiding Late Time Instability, Albert E. Ruehli, Luigi Lombardi, Giulio Antonini, Ye Tao, Michel S. Nakhla, Francesco Ferranti

Electrical and Computer Engineering Faculty Research & Creative Works

Late time instability is a key issue for obtaining time domain solutions using Computational Electromagnetic (CEM) full-wave techniques. However, impulse inputs lead to a convenient way to cascade time domain solutions for many problems. In this paper we show that stable impulse response solutions can be obtained for full-wave PEEC (Partial Element Equivalent Circuit) models which include retarded partial elements. The conventional time stepping technique is replaced by using the so called NILT (Numerical Inverse Laplace Transform) technique. We show that the late time unstable poles in the EM formulation are not excited by the NILT based solution.

Analysis Of Electromagnetic Vortex Beams Using Modified Dynamic Mode Decomposition In Spatial Angular Domain, Yanming Zhang, Menglin L.N. Chen, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The orbital angular momentum (OAM) modes of electromagnetic (EM) beams are utilized for multiplexing in communication systems, where each OAM mode is encoded with data. The OAM index, or the so-called topological charge, identifies each OAM mode. Recently, the amplitude of OAM mode has also been used as another modulation format. Therefore, accurate extraction of not only the OAM index but also the corresponding amplitude is required. In this paper, a modified dynamic mode decomposition (DMD) algorithm is proposed to analyze the OAM modes. We show that accurate topological charges and high-resolution amplitude patterns of both single OAM mode and …

Data To Risk-Informed Decisions Through Bridge Model Updating, Iris Tien

INSPIRE Archived Webinars

Across the country, bridge structures are aging with use commonly extending beyond their original design lives. Decisions to repair, retrofit or rehabilitate these structures will support continued reliability and resilience of these structures. To better understand the states of the bridges at any point in time, there are new technologies to inspect, monitor and assess bridge conditions.

To effectively use the results of these inspections and monitoring activities, we need an understanding of the relation between varying inspection parameters and the predicted performance of bridge structures.

In this seminar, we will describe methods to use inspection data to update assessment …

Iot-Based Cyber-Physical Communication Architecture: Challenges And Research Directions, Md Masud Rana, Rui Bo

Electrical and Computer Engineering Faculty Research & Creative Works

In order to provide intelligent services, the Internet of Things (IoT) facilitates millions of smart cyber-physical devices to be enabled with network connectivity to sense, collect, process, and exchange information. Unfortunately, the traditional communication infrastructure is vulnerable to cyber attacks and link failures, so it is a challenging task for the IoT to explore these applications. In order to begin research and contribute into the IoT-based cyber-physical digital world, one will need to know the technical challenges and research opportunities. In this study, several key technical challenges and requirements for the IoT communication systems are identified. Basically, privacy, security, intelligent …

Sequencing Heparan Sulfate Using Hilic Lc-Netd-Ms/Ms, Jiandong Wu, Juan Wei, Pradeep Chopra, Geert Jan Boons, Cheng Lin, Joseph Zaia

Chemical and Biochemical Engineering Faculty Research & Creative Works

Heparan Sulfate (HS) Mediates a Wide Range of Protein Binding Interactions Key to Normal and Pathological Physiology. Though Liquid Chromatography Coupled with Mass Spectrometry (LC-MS) based Disaccharide Composition Analysis is Able to Profile Changes in HS Composition, the Heterogeneity of Modifications and the Labile Sulfate Group Present Major Challenges for Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) Sequencing of the HS Oligosaccharides that Represent Protein Binding Determinants. Here, We Report Online LC-MS/MS Sequencing of HS Oligosaccharides using Hydrophilic Interaction Liquid Chromatography (HILIC) and Negative Electron Transfer Dissociation (NETD). a Series of Synthetic HS Oligosaccharides Varying in Chain Length (Tetramers and Hexamers), …

Inter-Comparison Of Reflectivity Measurements Between Gpm Dpr And Nexrad Radars, Munsung Keem, Bong Chul Seo, Witold F. Krajewski, K. Robert Morris

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study demonstrates the potential use of the NASA's Global Precipitation Measurement (GPM) Dual-frequency Precipitation Radar (DPR) to examine ground radar (GR) miscalibration and other uncertainty sources (e.g., partial beam blockage). We acquired the GPM Ground Validation System Validation Network reflectivity matchups between the DPR and three GRs (two in Iowa and one in South Dakota) for 2014–2017. We then refined the matching parameters (e.g., time separation) to reduce uncertainty in the matchup samples by analyzing the sensitivity of the matchup statistical properties to changes in these parameters. To reconcile the same observables (i.e., reflectivity) with different observational properties among …

Editorial: Bio-Inspired Audio Processing, Models And Systems, Shih Chii Liu, John G. Harris, Mounya Elhilali, Malcolm Slaney

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

A Novel Method Of Using Iron Nanoparticles From Coal Fly Ash Or Ferric Chloride For Acid Mine Drainage Remediation, Crisanda Gilbert, Olushola S. Ayanda, Olanrewaju O. Fatoba, Godfrey Madzivire, Leslie F. Petrik

Mining Engineering Faculty Research & Creative Works

Iron nanoparticles (nano Fe) were extracted from coal fly ash (CFA) or ferric chloride (FeCl3) and used for acid mine drainage (AMD) remediation. Characterization was achieved by X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy-energy dispersive spectroscopy (SEM–EDX), high resolution transmission electron microscopy (HRTEM), and the Braunaer–Emmet–Teller (BET) surface area determination. The HRTEM indicated good dispersion of the characteristic bead-like structure of nano Fe. It was also observed that the nano Fe were mainly in the zero-valent oxidation state, as denoted by the characteristic peak at ≈ 44.7° in the XRD analysis; it was accompanied by the generally accepted oxide …

Output-Constrained Control Of Nonaffine Multiagent Systems With Partially Unknown Control Directions, Bo Fan, Qinmin Yang, Sarangapani Jagannathan, Youxian Sun

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an output-constrained control algorithm is presented for the consensus control of a class of unknown nonaffine multiagent systems (MASs) with partially unknown control directions. Our contribution includes a step forward beyond the usual consensus stabilization result to show that the outputs of agents remain within user-defined time-varying constraints. To achieve the new results, an error transformation technique is established to generate an equivalent MAS from the original one. Stabilization and consensus of the transformed agent states ensure both the satisfaction of the time-varying constraints and the consensus of the original agent states. Based on the Nussbaum gain …

Tvs Devices Transient Behavior Modeling Framework And Application To Seed, Li Shen, Shubhankar Marathe, Javad Meiguni, Guangxiao Luo, Jianchi Zhou, David Pommerenke

Electrical and Computer Engineering Faculty Research & Creative Works

The transient behavior for four different types of TVS (non-snapback, snapback, spark gap, varistor) is modeled using the same modeling framework. By a 10 ns VF-TLP, the quasi-static I-V curve and the transient turn-on are captured and modeled in ADS. The models are applied in a SEED simulation to investigate the strengths and weaknesses of the modeling frame.

Measurement Of Adhesion Of Sternal Wires To A Novel Bioactive Glass-Based Adhesive, Varinder Pal Singh Sidhu, Mark R. Towler, Marcello Papini

Chemical and Biochemical Engineering Faculty Research & Creative Works

Stainless steel wires are the standard method for sternal closure because of their strength and rigidity, the simplicity of the process, and the short healing time that results from their application. Despite this, problems still exist with sternal stability due to micromotion between the two halves of the dissected and wired sternum. Recently, a novel glass-based adhesive was developed which, in cadaveric trials and in conjunction with wiring, was shown to restrict this micromotion. However, in order to avoid complications during resternotomy, the adhesive should adhere only to the bone and not the sternal wire. In this study, sternal wires …

Evaluation Of A 38 L Explosive Chamber For Testing Coal Dust Explosibility, Robert Eades, Kyle A. Perry

Mining Engineering Faculty Research & Creative Works

Coal dust explosions are the deadliest disasters facing the coal mining industry. Research has been conducted globally on this topic for decades. The first explosibility tests in the United States were performed by the Bureau of Mines using a 20 L chamber. This serves as the basis for all standardized tests used for combustible dusts. The purpose of this paper is to investigate the use of a new 38 L chamber for testing coal dust explosions. The 38 L chamber features design modifications to model the unique conditions present in an underground coal mine when compared to other industries where …

Compact Endfire Coupled-Mode Patch Antenna With Vertical Polarization, Haozhan Tian, Lijun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

Coupled-mode patch antenna (CMPA) is able to reform the beam by manipulating the phase of the fringing fields at the edges. In this paper, a method is proposed to realize endfire radiation with vertical polarization based on the concept of CMPA. Besides the phase controlled by the coupling, the asymmetric feeding introduces additional phase shift to one of the radiation slots, which makes the beam pointing to the forward endfire direction within the whole band. The ground of the antenna is truncated to be the same size of the top patch, which eliminates the undesired effect of the ground edge …

Discontinuous Galerkin Vs. Ie Method For Electromagnetic Scattering From Composite Metallic And Dielectric Structures, Y.-Y. Zhu, Q.-M. Cai, R. Zhang, X. Cao, Y.-W. Zhao, B. Gao, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, an efficient volume surface integral equation (VSIE) method with nonconformal discretization is developed for the analysis of electromagnetic scattering from composite metallic and dielectric (CMD) structures. This VSIE scheme utilizes curved tetrahedral (triangular) elements for volume (surface) modeling and the associated CRWG (CSWG) basis functions for volume current (surface) current modeling. Further, a discontinuous Galerkin (DG) volume integral equation (VIE) method and a DG surface integral equation (SIE) approach are adopted for dielectric and metallic parts, respectively, which allow both conformal and nonconformal volume/surface discretization improving meshing flexibility considerably. Numerical results are provided to demonstrate the accuracy, …

Control Of A Three-Phase Grid-Connected Inverter Under Non-Ideal Grid Conditions With Online Parameter Update, Vikram Roy Chowdhury, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

Three-phase grid-connected inverter modeling depends on the equivalent resistance and inductance between the inverter and the grid. However, these parameters are not fixed during the operation of the inverter and vary with the operating conditions. In this paper, a new globally stable adaptive controller is proposed to estimate these values online and update the controller during its operation. A model reference adaptive system (MRAS) based on two fictitious quantities with no physical significance is utilized, namely M = v · i∗ and N = v∗ x i, where v and i are the steady-state values of voltage and current in …

Strong Circular Dichroism In Chiral Plasmonic Metasurfaces Optimized By Micro-Genetic Algorithm, Zhigang Li, Daniel Rosenmann, David A. Czaplewski, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Strong circular dichroism in absorption in the near-infrared wavelength range is realized by designing binary-pattern chiral plasmonic metasurfaces via the micro-genetic algorithm optimization method. The influence of geometric parameter modifications in the binary-pattern nanostructures on the circular dichroism performance is studied. The strong circular dichroism in absorption is attributed to the simultaneous excitation and field interference of the resonant modes with relative phase delay under linearly polarized incident light. This work provides a universal design method toward the on-demand properties of chiral metasurfaces, which paves the way for future applications in chemical and biological sensing, chiral imaging and spectroscopy.

Influence Of Guayule Resin As A Bio-Based Additive On Asphalt-Rubber Binder At Elevated Temperatures, Ahmed Hemida, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt-rubber-guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of the guayule …

The Potential Of Using Micro-Sized Crosslinked Polymer Gel To Remediate Water Leakage In Cement Sheaths, Murad Abdulfarraj, Abdulmohsin Imqam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Cementing is a major step in the construction and sealing of hydrocarbon wells. During the life cycle of the well, cement is prone to cracking due to a change in downhole conditions. This research investigates the use of micro-sized crosslinked polymer gel as a sealant material to mitigate cracked cement sheaths. Two experimental setups were designed to investigate water leakage through cement. The impact of polymer gel strength on the gel's ability to seal cement cracks was investigated using four gel strengths, including 500 pa, 1200 pa, 1450 pa, and 2440 pa. The impact of the width of the cement …

Rare But Conceivable: Determining The Likelihood Of Meteors And Other Infrequent Events, Michael S. Schmidt, Maria Vega-Westhoff

Engineering Management and Systems Engineering Faculty Research & Creative Works

In the aftermath of a rare but devastating disaster, there is a tendency to overestimate how frequent such an event may be, hence a tendency to overestimate the risk associated with such an event. Those concerned with process safety will acknowledge that though rare, events like meteors, hurricanes, and airplane crashes that can impact chemical plants are conceivable. Typically, though, they have nothing more than feelings to decide whether these events are likely enough to be considered "credible." This compiles data from the literature for several "meteors," both natural and man-made, that often become a cause of general concern after …

Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The material science of additive manufacturing (AM) has become a significant topic due to the unique way in which the material and geometry are created simultaneously. Major areas of research within inorganic materials include traditional structural materials, shape memory alloys, amorphous materials, and some new work in intermetallics. The unique thermal profiles created during selective laser melting (SLM) may provide new opportunities for processing intermetallics to improve mechanical and magnetic performance. A parameter set for the production of Fe-Co-2V material with additive manufacturing is developed and efforts are made to compare the traditional wrought alloy to the AM version of …

Reliability-Based Design Optimization Of Load Sharing Systems Using Ssi-Markov Models, Arun Bala Subramaniyan, Rong Pan, Xiaoping Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents a novel single loop approach to design the components of the load sharing systems by optimally allocating the failure probabilities to each component, thereby satisfying the overall system reliability requirement. The Reliability–Based Design Optimization (RBDO) of load sharing systems is computationally intensive due to the dynamic nature of component failure probabilities, since the failure of one component will vary the failure probabilities of other working components. Many RBDO methods have been successfully utilized to design individual components, however using these methods for handling system level reliability constraints is still a challenging task. This is because of a …

Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The hydrophobicity of electro spun poly-l-lactic acid (PLLA) fibers hinders their integration with surrounding tissue for a variety of applications. In this study, we increased PLLA fiber hydrophilicity by incorporating the natural surfactant, lactonic sophorolipid (LSL). PLLA+LSL fibers had similar fiber morphology but significantly greater surface wettability, which suggested LSL accumulation on the fiber surface. Differential scanning calorimetry results also suggested that LSL was phase separated from PLLA. Despite the altered surface wettability of these fibers, there was no change in fibroblast adhesion. Future studies may explore the use of this natural surfactant to deliver bioactive factors to enhance fibroblast …

Elevated Temperature Mechanical And Microstructural Characterization Of Slm Ss304l, G. R. Hecht, Sriram Praneeth Isanaka, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

SLM built SS304L was annealed and water quenched to minimize residual stress and avoid carbide precipitation. Mini-tensile characterization of strength and elongation at temperature conditions up to 800°C, along with observations of the associated microstructural transformations were utilized to understand the changes produced in SLM SS304L. As-built and annealed specimens were found to exhibit decreasing strength and elongation with increasing temperature as expected. Carbide precipitates appeared after short times at high temperatures within both as-built and annealed specimens for all cases, but no brittle intermetallic phase development was observed for any of the temperatures investigated. While the lack of Sigma, …

Frequency Inspection Of Additively Manufactured Parts For Layer Defect Identification, Aimee Allen, Kevin Johnson, Jason R. Blough, Andrew Barnard, Troy Hartwig, Ben Brown, David Soine, Tristan Cullom, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive manufactured (AM) parts are produced at low volume or with complex geometries. Identifying internal defects is difficult as current testing techniques are not optimized for AM processes. The goal of this paper is to evaluate defects on multiple parts printed on the same build plate. The technique used was resonant frequency testing with the results verified through Finite Element Analysis. From these tests, it was found that the natural frequencies needed to detect the defects were higher than the excitation provided by a modal hammer. The deficiencies in this range led to the development of other excitation methods. Based …

Joining Of Copper And Stainless Steel 304l Using Direct Metal Deposition, Xinchang Zhang, Yitao Chen, Tan Pan, Wenyuan Cui, Lan Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In the current study, the feasibility of joining pure copper (Cu) and stainless steel 304L (SS304L) through direct metal deposition process was investigated by material characterization. Samples were analyzed in terms of microstructure, elemental distribution, and tensile testing. Direct depositing pure copper on SS304L shows copper was mechanically rather than metallurgical bonded with SS304L due to the poor dissolubility of iron in copper. Iron was diffused into copper with a diluted distance of 1.5 mm and above that, pure copper deposits were obtained. Columnar structure was observed at the copper region near the interface while the columnar grains became finer …

Simulated Effect Of Laser Beam Quality On The Robustness Of Laser-Based Am System, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In many metal AM techniques, a laser is used as the heat source and in some applications, it can be advantageous to work off of the focal plane. When operating outside of focus, the beam quality of the laser can have drastic impacts on the ability to manufacture quality parts. This study investigates the effect of the beam quality and distance from the focal plan on the ability to deposit Ti-64, aluminum, and steel through the simulation of the blown powder process.