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Articles 1621 - 1650 of 21777

Full-Text Articles in Engineering

Quantification Of Geodetic Strain Rate Uncertainties And Implications For Seismic Hazard Estimates, Jeremy Maurer, Kathryn Materna Sep 2023

Quantification Of Geodetic Strain Rate Uncertainties And Implications For Seismic Hazard Estimates, Jeremy Maurer, Kathryn Materna

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Geodetic velocity data provide first-order constraints on crustal surface strain rates, which in turn are linked to seismic hazard. Estimating the 2-D surface strain tensor everywhere requires knowledge of the surface velocity field everywhere, while geodetic data such as Global Navigation Satellite System (GNSS) only have spatially scattered measurements on the surface of the Earth. To use these data to estimate strain rates, some type of interpolation is required. In this study, we review methodologies for strain rate estimation and compare a suite of methods, including a new implementation based on the geostatistical method of kriging, to compare variation between …

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Qc-Sane: Robust Control In Drl Using Quantile Critic With Spiking Actor And Normalized Ensemble, Surbhi Gupta, Gaurav Singal, Deepak Garg, Sarangapani Jagannathan Sep 2023

Qc-Sane: Robust Control In Drl Using Quantile Critic With Spiking Actor And Normalized Ensemble, Surbhi Gupta, Gaurav Singal, Deepak Garg, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Recently Introduced Deep Reinforcement Learning (DRL) Techniques in Discrete-Time Have Resulted in Significant Advances in Online Games, Robotics, and So On. Inspired from Recent Developments, We Have Proposed an Approach Referred to as Quantile Critic with Spiking Actor and Normalized Ensemble (QC-SANE) for Continuous Control Problems, Which Uses Quantile Loss to Train Critic and a Spiking Neural Network (NN) to Train an Ensemble of Actors. the NN Does an Internal Normalization using a Scaled Exponential Linear Unit (SELU) Activation Function and Ensures Robustness. the Empirical Study on Multijoint Dynamics with Contact (MuJoCo)-Based Environments Shows Improved Training and Test Results Than …

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Fs-Laser Fabricated Miniature Fabry–Perot Interferometer In A No-Core Fiber For High-Temperature Applications †, Chen Zhu, Osamah Alsalman, Jie Huang Sep 2023

Fs-Laser Fabricated Miniature Fabry–Perot Interferometer In A No-Core Fiber For High-Temperature Applications †, Chen Zhu, Osamah Alsalman, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Reports a Fiber In-Line Fabry–Perot Interferometer (FPI) Fabricated in a No-Core Fiber using the Direct Femtosecond Laser Writing Technique for High-Temperature Sensing Applications. Two In-Line Reflectors Are Directly Inscribed in a No-Core Fiber to Construct a Low-Finesse FPI. Fringe Visibility Greater Than 10 DB is Obtained from the Reflection Spectra of the Fabricated No-Core Fiber FPIs. Temperature Responses of a Prototype No-Core Fiber FPI Are Characterized Up to 1000 °C. the Proposed Configuration is Compact and Easy to Fabricate, Making It Attractive for Sensing Applications in High-Temperature Harsh Environments.

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Discrete Choice Experiment Consideration: A Framework For Mining Community Consultation With Case Studies, Sisi Que, Yu Huang, Kwame Awuah-Offei, Liang Wang, Songlin Liu Sep 2023

Discrete Choice Experiment Consideration: A Framework For Mining Community Consultation With Case Studies, Sisi Que, Yu Huang, Kwame Awuah-Offei, Liang Wang, Songlin Liu

Mining Engineering Faculty Research & Creative Works

Local community acceptance, a key indicator of the socio-political risk of a project, is addressed through good stakeholder (community) engagement. Discrete choice modeling (DCM) enhances stakeholder analysis and has been widely applied to encourage community engagement in energy projects. However, very little detail is provided on how researchers design discrete choice experiments (DCEs). DCE design is the key step for effective and efficient data collection. Without this, the discrete choice model may not be meaningful and may be misleading in the local community engagement effort. This paper presents a framework for mining community engagement DCE design in an attempt to …

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In Situ Monitoring Of The Hydration Of Calcium Silicate Minerals In Cement With A Remote Fiber-Optic Raman Probe, Bohong Zhang, Wenyu Liao, Hongyan Ma, Jie Huang Sep 2023

In Situ Monitoring Of The Hydration Of Calcium Silicate Minerals In Cement With A Remote Fiber-Optic Raman Probe, Bohong Zhang, Wenyu Liao, Hongyan Ma, Jie Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study utilized a novel in situ fiber-optic Raman probe to continuously monitor the hydration progress of tricalcium silicate (C3S) and dicalcium silicate (C2S) without the need for sampling, from early hydration stage to later stages, and from fresh to hardened states of paste samples. By virtue of the remarkable ability of this technique in characterizing either dry or wet and crystalline or amorphous samples, the hydration processes of C3S and C2S pastes with different water-to-solid (w/s) ratios could be monitored from the start of the hydration reaction. The main hydration products, …

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Data-Driven Analysis Of Construction Bidding Stage-Related Causes Of Disputes, Muaz O. Ahmed, Islam H. El-Adaway Sep 2023

Data-Driven Analysis Of Construction Bidding Stage-Related Causes Of Disputes, Muaz O. Ahmed, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction bidding is a complex process that involves several potential risks and uncertainties for all the stakeholders involved. Such complexities, risks, and uncertainties, if uncontrolled, can lead to the rise of claims, conflicts, and disputes during the course of a project. Even though a substantial amount of knowledge has been acquired about construction disputes and their causation, there is a lack of research that examines the causes of disputes associated with the bidding phase of projects. This study addresses this knowledge gap within the context of infrastructure projects. In investigating and analyzing the causation of disputes related to the bidding …

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A Focused Review On Recycling And Hydrolysis Techniques Of Polyethylene Terephthalate, Hossein Abedsoltan Sep 2023

A Focused Review On Recycling And Hydrolysis Techniques Of Polyethylene Terephthalate, Hossein Abedsoltan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Polyethylene terephthalate (PET) is used in textile and packaging industries. The main source of PET production is fossil fuels with limited capacity. Also, PET products are single use that transform into high volumes of wastes, causing ecosystem problems. Recycling is proposed to confront this challenge. The four major PET recycling techniques are mechanical, chemical, pyrolysis, and enzymatic. Mechanical, pyrolysis, and enzymatic techniques have constrained capabilities to manage PET waste. Chemical recycling is the potential path to expanding recycling PET waste with possibility of upcycling and addressing dirty waste streams. Several chemical methods are introduced and discussed in literature. The five …

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Multifunctional Organic Monolayer-Based Coatings For Implantable Biosensors And Bioelectronic Devices: Review And Perspectives, Taral Patel, Jie Huang, Katarzyna Krukiewicz Sep 2023

Multifunctional Organic Monolayer-Based Coatings For Implantable Biosensors And Bioelectronic Devices: Review And Perspectives, Taral Patel, Jie Huang, Katarzyna Krukiewicz

Electrical and Computer Engineering Faculty Research & Creative Works

The Emerging Field of Biosensors and Bioelectronics Seeks to Exploit Biology in Combination with the Recent Advances in Engineering. Even Though Biomedical Implants Can Significantly Improve Quality of Life, Problems Following the Process of Implantation Are Still an Issue. in This Review, We Point Out Organic Monolayer-Based Coatings as a Potential Solution to the Major Limitations of Implantable Biomaterials, Including Limited Biocompatibility, the Risk of Biofouling, Bacterial Colonization, and Stability under in Vivo Conditions. at First, Selected Current and Perspective Biomaterials Are Discussed, with the Focus on their Use as Implantable Biosensors and Biomedical Electrodes. Surface Modification Strategies for Implantable …

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In Situ Monitoring Of The Hydration Of Calcium Silicate Minerals In Cement With A Remote Fiber-Optic Raman Probe, Bohong Zhang, Wenyu Liao, Hongyan Ma, Jie Huang Sep 2023

In Situ Monitoring Of The Hydration Of Calcium Silicate Minerals In Cement With A Remote Fiber-Optic Raman Probe, Bohong Zhang, Wenyu Liao, Hongyan Ma, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This study utilized a novel in situ fiber-optic Raman probe to continuously monitor the hydration progress of tricalcium silicate (C3S) and dicalcium silicate (C2S) without the need for sampling, from early hydration stage to later stages, and from fresh to hardened states of paste samples. by virtue of the remarkable ability of this technique in characterizing either dry or wet and crystalline or amorphous samples, the hydration processes of C3S and C2S pastes with different water-to-solid (w/s) ratios could be monitored from the start of the hydration reaction. the main hydration products, calcium silicate hydrate (C–S–H) and portlandite/calcium hydroxide (CH), …

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Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang Aug 2023

Large-Scale Cascading Of First-Order Fbg Array In A Highly Multimode Coreless Fiber Using Femtosecond Laser For Distributed Thermal Sensing, Farhan Mumtaz, Bohong Zhang, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research focuses on the performance analysis and characterization of a fiber Bragg gratings (FBGs) array, consisting of 10 first order FBGs inscribed by a femtosecond (FS) laser in a highly multimode coreless fiber. The study evaluates the FBG array's ability to function as a distributed thermal sensing (DTS) platform, with the coreless fiber chosen as the sensing element due to its immunity to dopant migration at high temperatures. The design of a large cascaded first-order FBG array effectively eliminates unwanted harmonic peaks across a wide spectrum range. In contrast, higher-order FBGs introduce limitations due to the overlapping of Bragg …

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Defect Generation Mechanisms In Silica Under Intense Electronic Excitation By Ion Beams Below 100 K: Interplay Between Radiative Emissions, M. L. Crespillo, Joseph T. Graham, W. J. Weber, F. Agulló-López Aug 2023

Defect Generation Mechanisms In Silica Under Intense Electronic Excitation By Ion Beams Below 100 K: Interplay Between Radiative Emissions, M. L. Crespillo, Joseph T. Graham, W. J. Weber, F. Agulló-López

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Ion-beam effects on bulk silica at low temperature have been studied with the aim of understanding the routes and mechanisms leading from the initial generation of free carriers and self-trapped excitons (STEs) to the production of two stable defect structures in irradiated silica, non-bridging oxygen hole centers (NBOHCs) and oxygen deficient centers (ODCs). Ion beam induced luminescence (ionoluminescence, IL) spectra were obtained using 3 MeV H, 3.5 MeV He, 19 MeV Si, and 19 MeV Cl ions and a range of cryogenic irradiation temperatures from 30 to 100 K. The kinetic behavior of three emission bands centered at 1.9 eV …

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Stochastic Modeling Of Physical Drag Coefficient – Its Impact On Orbit Prediction And Space Traffic Management, Smriti Nandan Paul, Phillip Logan Sheridan, Richard J. Licata, Piyush M. Mehta Aug 2023

Stochastic Modeling Of Physical Drag Coefficient – Its Impact On Orbit Prediction And Space Traffic Management, Smriti Nandan Paul, Phillip Logan Sheridan, Richard J. Licata, Piyush M. Mehta

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ambitious satellite constellation projects by commercial entities and the ease of access to space in recent times have led to a dramatic proliferation of low-Earth space traffic. It jeopardizes space safety and long-term sustainability, necessitating better space domain awareness (SDA). Correct modeling of uncertainties in force models and orbital states, among other things, is an essential part of SDA. For objects in the low-Earth orbit (LEO) region, the uncertainty in the orbital dynamics mainly emanate from limited knowledge of the atmospheric drag-related parameters and variables. In this paper, which extends the work by Paul et al. (2021), we develop a …

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Final Report - Augmenting Bridge Inspection With Augmented Reality And Haptics Based Aerial Manipulation, Paul Oh, Blake Hament, Dongbin Kim Aug 2023

Final Report - Augmenting Bridge Inspection With Augmented Reality And Haptics Based Aerial Manipulation, Paul Oh, Blake Hament, Dongbin Kim

Project AS-7

Insight and leverage from prior project identified the need for haptics; the inspector’s sense of touch is often used in bridge assessment. Envisioned is the augmentation of bridge personnel by providing a haptics-based aerial manipulator. Such a manipulator would reduce needs to ascend elevated structures like under bridge decks and cabling. There is recent work that uses haptics in aerial manipulation. But these center on autonomous multi-drone flight formation for aerial shows or cooperative object delivery and are relatively straight-forward. The sense of touch is used to provide spatial distance between drones. By contrast, this proposal’s novelty and merit are …

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Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady Aug 2023

Utilizing Waste Latex Paint Toward Improving The Performance Of Concrete, Mohamed Leithy, Eslam Gomaa, Ahmed A. Gheni, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this paper, incorporating the waste latex paint (WLP) into the conventional concrete as a partial replacement of sand to improve its durability was investigated. The fresh and hardened characterizations, in addition to the durability of concrete, were examined. The slump test was used to evaluate the fresh properties, while the hardened properties were evaluated through the volume of voids and absorption rate, in addition to the compressive, splitting tensile, and flexural strengths tests. The durability performance was evaluated by the surface resistivity, bulk electrical resistivity, as well as freeze and thaw resistance tests. The results showed a reduction in …

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Behavior Of Ultrahigh-Performance Concrete Plates Encasing Steel H-Piles, Mohamed Elgawady, Binod Shrestha Aug 2023

Behavior Of Ultrahigh-Performance Concrete Plates Encasing Steel H-Piles, Mohamed Elgawady, Binod Shrestha

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel H-piles are exposed during their service life to wet-dry cycles in combination with salts, such as deicing, that may result in corrosion, leading to cross-sectional loss and reduction in axial load-carrying capacity. This paper proposes an innovative repair method for corroded steel H-piles using ultrahigh-performance concrete (UHPC) plates. The UHPC plates are reinforced with carbon fiber-reinforced polymer (CFRP) grids. The UHPC plates bridge the corroded segment so that the axial force bypasses the corroded segment. The UHPC are bolted to the steel H-pile using high-strength bolt connectors (HSBCs). Eleven steel H-piles bolted with UHPC plates were investigated experimentally under …

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Effect Of Competitive Adsorption Between Specialty Admixtures And Superplasticizer On Structural Build-Up And Hardened Property Of Mortar Phase Of Ultra-High-Performance Concrete, Le Teng, Jingjie Wei, Kamal Khayat, Joseph J. Assaad Aug 2023

Effect Of Competitive Adsorption Between Specialty Admixtures And Superplasticizer On Structural Build-Up And Hardened Property Of Mortar Phase Of Ultra-High-Performance Concrete, Le Teng, Jingjie Wei, Kamal Khayat, Joseph J. Assaad

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study aims to enhance structural build-up of ultra-high-performance concrete (UHPC) without influencing the initial flowability, which is critical in repair applications (e.g., use of UHPC in thin bonded overlays for bridge deck rehabilitation). Specialty admixtures, such as a viscosity-modifying admixture (VMA), have been used to enhance the structural build-up at rest. However, the use of specialty admixtures can increase superplasticizer (SP) demand to maintain proper flowability; the synergistic effect of these admixtures on structural build-up is not well understood as the coupled admixture content can reverse the net effect on yield stress, viscosity, and thixotropy. In this study, VMAs …

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Genesis Of The 1.45 Ga Kratz Spring Iron Oxide-Apatite Deposit Complex In Southeast Missouri, Usa: Constraints From Oxide Mineral Chemistry, Brandon Sullivan, Marek Locmelis, Bolorchimeg N. Tunnell, Cheryl M. Seeger, Marilena Moroni, Sarah Dare, Ryan Mathur, Thomas Schott Aug 2023

Genesis Of The 1.45 Ga Kratz Spring Iron Oxide-Apatite Deposit Complex In Southeast Missouri, Usa: Constraints From Oxide Mineral Chemistry, Brandon Sullivan, Marek Locmelis, Bolorchimeg N. Tunnell, Cheryl M. Seeger, Marilena Moroni, Sarah Dare, Ryan Mathur, Thomas Schott

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Seven major and numerous lesser Fe oxide occurrences within the 1.47 Ga St. Francois Mountains terrane in Missouri (USA) have previously been described as iron oxide-apatite (IOA) and iron oxide-copper-gold (IOCG) deposits. Researchers speculate that these contain significant amounts of critical minerals, most notably rare earth elements and cobalt. One of the less-studied deposits in the region is the 1.455 Ga Kratz Spring deposit. The deposit consists of two steeply dipping magnetite bodies beneath 450 m of sedimentary cover. The genesis of the Kratz Spring deposit and its relationship to nearby IOA-IOCG deposits remains poorly constrained. To better understand the …

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A Direct Data Approach To Joint 2-D Doa And Frequency Estimation With L-Shaped Array, Yanming Zhang, Lijun Jiang Aug 2023

A Direct Data Approach To Joint 2-D Doa And Frequency Estimation With L-Shaped Array, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This article presents a joint two-dimensional dynamic mode decomposition (JTDDMD) approach to estimate the azimuth angle, elevation angle, and frequency for multiple narrowband sources using the L-shaped array. According to the placement position of different coordinate axes of the receiving antenna in the array, i.e., x- or z-axis, the received signal is divided into two datasets. Two-dimensional dynamic mode decomposition (TDDMD), the sub algorithm of JTDDMD, is used twice to deal with these two datasets separately. Through the analysis of the x-axis subarray received signal using TDDMD, the electrical angle in the x-direction and frequency are obtained with automatic pairing. …

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Effect Of Shock Tunnel Geometry On Shockwave And Vortex Ring Formation, Propagation, And Head On Collision, Rachel L. Bauer, Emily M. Johnson, Alexander D. Douglas, Catherine E. Johnson Aug 2023

Effect Of Shock Tunnel Geometry On Shockwave And Vortex Ring Formation, Propagation, And Head On Collision, Rachel L. Bauer, Emily M. Johnson, Alexander D. Douglas, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Vortex ring research primarily focuses on the formation from circular openings. Consequently, the role of tunnel geometry is less understood, despite there being numerous research studies using noncircular shock tunnels. This experimental study investigated shockwaves and vortex rings from different geometry shock tunnels from formation at the tunnel opening to head on collision with another similarly formed vortex ring using schlieren imaging and statistical analysis. The velocity of the incident shockwave was found to be consistent across all four shock tunnel geometries, which include circle, hexagon, square, and triangle of the same cross-sectional area. The velocity was 1.2 ± 0.007 …

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Design And Simulation Of A Utility Oilfield Flare In Iraq/Kurdistan Region Using Cfd And Api-521 Methodology, Ahmed A. Maaroof, Joseph D. Smith, Mohammed H.S. Zangana Aug 2023

Design And Simulation Of A Utility Oilfield Flare In Iraq/Kurdistan Region Using Cfd And Api-521 Methodology, Ahmed A. Maaroof, Joseph D. Smith, Mohammed H.S. Zangana

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper aims at reviewing and analyzing the operation and design of a utility flare in an oilfield in the Iraq/Kurdistan region. The flare supports a gas separation unit that separates 100 MMSCFD of natural gas from other liquid compounds in petroleum refining. The actual flare dimensions are 50 m high and 0.6 m diameter and works in summer where the crosswind speed is 9 m/s and a flow of 1.2 MMSCFD of treated natural gas is flaring through it. At the beginning, the flare design was performed using the API-521 recommended approach based on full operating capacity of the …

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Development And Characterization Of Coal-Based Thermoplastic Composite Material For Sustainable Construction, Haibin Zhang, Wenyu Liao, Genda Chen, Hongyan Ma Aug 2023

Development And Characterization Of Coal-Based Thermoplastic Composite Material For Sustainable Construction, Haibin Zhang, Wenyu Liao, Genda Chen, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The exploitation of coal and the disposal of waste plastic present significant environmental and economic challenges that require sustainable and profitable solutions. In response, we propose a renewable construction composite material of coal-based thermoplastic composite (CTC) that can be made from low-grade coal and plastic waste. We developed and tested the hot-press fabrication method for this CTC, using coal with a maximum particle size of 4.75 mm and recycled high-density polyethylene (HDPE). The effects of the coal fraction (50–80 wt.%) on compressive properties, thermal properties, microstructure, and ecological and economic efficiencies of the CTC were investigated. Test results revealed that …

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Machine Learning-Based Seismic Damage Assessment Of Residential Buildings Considering Multiple Earthquake And Structure Uncertainties, Xinzhe Yuan, Liujun Li, Haibin Zhang, Yanping Zhu, Genda Chen, Cihan H. Dagli Aug 2023

Machine Learning-Based Seismic Damage Assessment Of Residential Buildings Considering Multiple Earthquake And Structure Uncertainties, Xinzhe Yuan, Liujun Li, Haibin Zhang, Yanping Zhu, Genda Chen, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Wood-frame structures are used in almost 90% of residential buildings in the United States. It is thus imperative to rapidly and accurately assess the damage of wood-frame structures in the wake of an earthquake event. This study aims to develop a machine-learning-based seismic classifier for a portfolio of 6,113 wood-frame structures near the New Madrid Seismic Zone (NMSZ) in which synthesized ground motions are adopted to characterize potential earthquakes. This seismic classifier, based on a multilayer perceptron (MLP), is compared with existing fragility curves developed for the same wood-frame buildings near the NMSZ. This comparative study indicates that the MLP …

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Distinct Modes Of Aged Soil Carbon Export In A Large Tropical Lake Basin Identified Using Bulk And Compound-Specific Radiocarbon Analyses Of Fluvial And Lacustrine Sediment, Wesley G. Parker, Jason M.E. Ahad, Jonathan Obrist-Farner, Benjamin Keenan, Peter M.J. Douglas Aug 2023

Distinct Modes Of Aged Soil Carbon Export In A Large Tropical Lake Basin Identified Using Bulk And Compound-Specific Radiocarbon Analyses Of Fluvial And Lacustrine Sediment, Wesley G. Parker, Jason M.E. Ahad, Jonathan Obrist-Farner, Benjamin Keenan, Peter M.J. Douglas

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The 14C content of sedimentary organic matter (OM) and specific organic molecules provide valuable information on the source and age of OM stored in sediments, but these data are limited for tropical fluvial and lake sediments. We analyzed 14C in bulk OM, palmitic acid (C16), and long-chain n-alkanoic acids (C24, C26, and C28), within fluvial and lake sediments in the catchment of Lake Izabal, a large tectonic lake basin in Guatemala. We combined these measurements with bulk and compound-specific δ13C measurements, as well as sediment organic carbon to nitrogen (OC:N) ratios, to understand the source and age of sedimentary OM …

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Electrosteric Control Of The Aggregation And Yielding Behavior Of Concentrated Portlandite Suspensions, Sharu Bhagavathi Kandy, Narayanan Neithalath, Mathieu Bauchy, Aditya Kumar, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant Aug 2023

Electrosteric Control Of The Aggregation And Yielding Behavior Of Concentrated Portlandite Suspensions, Sharu Bhagavathi Kandy, Narayanan Neithalath, Mathieu Bauchy, Aditya Kumar, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

Portlandite (calcium hydroxide: CH: Ca (OH)2) suspensions aggregate spontaneously and form percolated fractal aggregate networks when dispersed in water. Consequently, the viscosity and yield stress of portlandite suspensions diverge at low particle loadings, adversely affecting their processability. Even though polycarboxylate ether (PCE)-based comb polyelectrolytes are routinely used to alter the particle dispersion state, water demand, and rheology of similar suspensions (e.g., ordinary portland cement suspensions) that feature a high pH and high ionic strength, their use to control portlandite suspension rheology has not been elucidated. This study combines adsorption isotherms and rheological measurements to elucidate the role of PCE composition …

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Localization And Identification Of Emi Sources In Shielding Enclosures Based On A Two-Step Source Reconstruction Method, Zi An Wang, Jun Fa Mao, Li (Lijun) Jun Jiang, Ping Li Aug 2023

Localization And Identification Of Emi Sources In Shielding Enclosures Based On A Two-Step Source Reconstruction Method, Zi An Wang, Jun Fa Mao, Li (Lijun) Jun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

Localization and identification of unknown electromagnetic interference (EMI) sources in shielding enclosures is a great challenge due to the complex electromagnetic environment. In this work, a two-step source reconstruction method is proposed to address this issue. The actual EMI sources are initially modeled by equally distributed equivalent electric dipoles in the shielding enclosure. Effects of surrounding environments are rigorously incorporated using the numerical Green's function which bridges between the equivalent dipoles and planar scanned tangential magnetic near-field. Next, the initial equivalent sources are downsized via evaluating the contribution of each equivalent dipole. The parameters of remaining equivalent dipoles are updated …

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Silicon Carbide-Based Dna Sensing Technologies, Abdulla Al Mamun, Mason Mcgarrity, Jong Hoon Kim, Feng Zhao Aug 2023

Silicon Carbide-Based Dna Sensing Technologies, Abdulla Al Mamun, Mason Mcgarrity, Jong Hoon Kim, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

DNA sensing is critical in various applications such as the early diagnosis of diseases and the investigation of forensic evidence, food processing, agriculture, environmental protection, etc. As a wide-bandgap semiconductor with excellent chemical, physical, electrical, and biocompatible properties, silicon carbide (SiC) is a promising material for DNA sensors. In recent years, a variety of SiC-based DNA-sensing technologies have been reported, such as nanoparticles and quantum dots, nanowires, nanopillars, and nanowire-based field-effect-transistors, etc. This article aims to provide a review of SiC-based DNA sensing technologies, their functions, and testing results.

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A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed Jul 2023

A Spike-Shaped Anchorage For Steel Reinforced Polymer (Srp)-Strengthened Concrete Structures, Xingxing Zou, Keenan L. Mcburney, Lesley H. Sneed

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Steel reinforced polymer (SRP) composite has recently emerged as an effective and economical solution for strengthening of reinforced concrete (RC) structures. Premature debonding failure of unanchored SRP at low load levels generally governs the performance of RC structures strengthened with externally bonded SRP. Therefore, a novel yet simple spike-shaped anchorage system was proposed in this study to prevent the debonding failure of SRP and to improve the interfacial shear capacity. Experimental investigation through single-lap shear tests of SRP-concrete joints showed that the anchorage system changed the failure mode from composite debonding to fiber rupture. In addition, the anchorage system substantially …

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In-Situ Lock-In Thermographic Measurement Of Powder Layer Thermal Diffusivity And Thickness In Laser Powder Bed Fusion, Tao Liu, Edward C. Kinzel, Ming-Chuan Leu Jul 2023

In-Situ Lock-In Thermographic Measurement Of Powder Layer Thermal Diffusivity And Thickness In Laser Powder Bed Fusion, Tao Liu, Edward C. Kinzel, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The thermal transport properties of the powder layer play a crucial role in the process of laser powder bed fusion (LPBF). This paper introduces an in-situ measurement method utilizing active lock-in infrared thermography (LIT) to determine the thermal diffusivity and thickness of the powder layer. The proposed method exhibits great potential for accurate powder property and thickness measurements and real-time process monitoring. In this lock-in thermographic technique, the LPBF laser beam is directed through an optical diffuser and modulated into a square thermal wave. This thermal wave serves as an active heat source to heat the surface of the powder …

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Experiential Learning And Exposure To Professional Experience In Civil Engineering Education, Sanjay Tewari Jul 2023

Experiential Learning And Exposure To Professional Experience In Civil Engineering Education, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Experiential learning is increasingly recognized as a crucial component of modern education, especially in fields like civil engineering, where practical skills and real-world exposure are paramount. This paper explores the various avenues through which civil engineering education can offer professional exposure and experiential learning opportunities. By analyzing the impact of senior seminars, internships, co-ops, undergraduate research, study abroad programs, service learning, student design teams, leadership positions, and involvement in technical and professional student organizations, this paper aims to underscore the importance of these approaches in shaping well-rounded and industry-ready civil engineers.

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A Natural Organic Artificial Synaptic Device Made From A Honey And Carbon Nanotube Admixture For Neuromorphic Computing, Md Mehedi Hasan Tanim, Zoe Templin, Kaleb Hood, Jun Jiao, Feng Zhao Jul 2023

A Natural Organic Artificial Synaptic Device Made From A Honey And Carbon Nanotube Admixture For Neuromorphic Computing, Md Mehedi Hasan Tanim, Zoe Templin, Kaleb Hood, Jun Jiao, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

Artificial synaptic devices are the essential hardware component in emerging neuromorphic computing systems by mimicking biological synapse and brain functions. When made from natural organic materials such as protein and carbohydrate, they have potential to improve sustainability and reduce electronic waste by enabling environmentally friendly disposal. In this paper, a new natural organic memristor based artificial synaptic device is reported with the memristive film processed by a honey and carbon nanotube (CNT) admixture, that is, honey-CNT memristor. Optical microscopy, scanning electron microscopy, and micro-Raman spectroscopy are employed to analyze the morphology and chemical structure of the honey-CNT film. The device …

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