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Full-Text Articles in Engineering

Near-Optimal Trajectory Tracking In Quadcopters Using Reinforcement Learning, Randal Engelhardt, Alberto Velazquez, Tohid Sardarmehni Jan 2024

Near-Optimal Trajectory Tracking In Quadcopters Using Reinforcement Learning, Randal Engelhardt, Alberto Velazquez, Tohid Sardarmehni

Mechanical Engineering Faculty Publications

The control of quadcopters poses significant challenges due to their complex dynamics characterized by highly nonlinear couplings, high system order, and under-actuation. This paper presents a novel control solution aimed at achieving near-optimal trajectory tracking for quadcopters. A near-optimal solution based on approximate dynamic programming is proposed to address the curse of dimensionality inherent in traditional dynamic programming, employing a single network adaptive critic. Extensive simulations validate the effectiveness and robustness of the proposed solution.


Zno Varistors—Preparation Of Nano And Micro Sized Powders By Mechanical Methods For Low And High Voltage Varistors, Maura Kelleher Jan 2024

Zno Varistors—Preparation Of Nano And Micro Sized Powders By Mechanical Methods For Low And High Voltage Varistors, Maura Kelleher

Books/Book Chapters

ZnO-Bi2O3-Sb2O3 varistors are as essential today as they have been since their discovery five decades ago. Their role is to protect other electronic components against oncoming surges of electrons and survive. The demands on varistors are increasing. Electronic components are becoming smaller and more sensitive, and the metal oxides from which varistors are made are precious. Every aspect of their structure (macro, micro, nano and atomic) determines how they perform and survive. Each stage and variable within the powder metallurgy process is important. The mechanical methods in preparing nano and micro sized metal oxide powders are outlined in this chapter.


Elevato-Cdr: Speech Enhancement In Large Delay And Reverberant Assisted Living Scenarios, Swarnadeep Bagchi, Ruairí De Fréin Jan 2024

Elevato-Cdr: Speech Enhancement In Large Delay And Reverberant Assisted Living Scenarios, Swarnadeep Bagchi, Ruairí De Fréin

Conference papers

Speech enhancement algorithms are needed for Assisted Living (AL) environments, which are characterized by large inter-microphone spacings, significant phase-wraparound, and high reverberation times (T60). We contribute Elevato- CDR, which addresses the task of enhancing speech given the large relative delays and high levels of reverberation, which are characteristic of AL scenarios. The purpose of this paper is to evaluate Elevato-CDR’s performance and compare it with benchmark reverberation schemes, using speech mixtures which experience reverberation and background noise. Our findings indicate that Elevato-CDR successfully outperforms classical dereverberation algorithms in terms of subjective (MARS, PESQ) and objective (SDR, SRR) performance measures in …


Alien Mystery Scavenger Hunt: Enhancing Intergenerational Interaction With Physical Web Technologies Through Location-Based Games, Folashade Fatima Badmos Jan 2024

Alien Mystery Scavenger Hunt: Enhancing Intergenerational Interaction With Physical Web Technologies Through Location-Based Games, Folashade Fatima Badmos

Conference papers

The Physical Web is a powerful, easy-to-implement and inexpensive way to bridge the gap between the digital and physical realms compared to other technologies used for web location-aware interaction. In this study, we propose a Physical Web for an inter-generational game through the Alien Mystery scavenger hunt. Through the design and implementation of a Physical Web for outdoor intergenerational games, we show the potential of Physical Web technologies in presenting different interactions between the web and the user’s physical environment. The game utilises the ubiquity of QR codes and NFC in modern mobile devices, enabling users to seamlessly interact with …


Privacy-Preserving Pedestrian Movement Analysis In Complex Public Spaces, Kunchala Anil Jan 2024

Privacy-Preserving Pedestrian Movement Analysis In Complex Public Spaces, Kunchala Anil

Doctoral

Every journey starts and ends with a walking phase. As a fundamental mode of transportation, it plays a crucial role in the functioning of urban societies. Cities should strive to create public spaces that promote walking by designing pedestrian-friendly infrastructure that is accessible, safe, and convenient for all. An essential step in designing pedestrian-friendly infrastructure is understanding pedestrian usage patterns and behaviour in existing public spaces and infrastructure.


Existing Gap Analysis Tool Inventory, Rahat Ullah, Adhban Omar Ahmed Farea, Joseph R. Harrington, Ted Mckenna, Sean Carroll Jan 2024

Existing Gap Analysis Tool Inventory, Rahat Ullah, Adhban Omar Ahmed Farea, Joseph R. Harrington, Ted Mckenna, Sean Carroll

Tools

The Digital Performance Indicator (DPI) is a valuable tool for organisations aiming to evaluate their digital capabilities. It is specifically designed to offer insights into how an organisation's digital performance compares with that of its peers. This indicator functions as a strategic tool, providing a clear understanding of an organisation's position within the digital landscape and offering actionable recommendations for enhancing its digital capabilities. The DPI is a dynamic resource that enables organisations to make informed decisions and maintain competitiveness in an increasingly digitised business environment.


Emotional Intelligence Coaching For Higher Education Lecturers: Their Experience And Its Impact On Trait Emotional Intelligence, Stress, And Teaching Self-Efficacy, Eoghan Guiry Jan 2024

Emotional Intelligence Coaching For Higher Education Lecturers: Their Experience And Its Impact On Trait Emotional Intelligence, Stress, And Teaching Self-Efficacy, Eoghan Guiry

Doctoral

Previous research has established that emotional intelligence (EI) can be developed through targeted intervention; however, this was previously untested with lecturers. Guided by the job demands-resources model, this study explored the impact of an EI coaching intervention on lecturers’ trait EI, perceived stress, work-related stress, and teaching self-efficacy at Technological University Dublin. Additionally, the study explored the lecturers’ experiences of partaking in the intervention. Employing a pragmatic approach, mixed methods were used in a randomised controlled trial.


Sic Addition To A Dual Phase High Entropy Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Kantesh Balani, Gregory E. Hilmas, Jeremy Watts Jan 2024

Sic Addition To A Dual Phase High Entropy Ultra-High Temperature Ceramic, Rubia Hassan, William G. Fahrenholtz, Kantesh Balani, Gregory E. Hilmas, Jeremy Watts

Materials Science and Engineering Faculty Research & Creative Works

Dual phase (Hf,Ta,Ti,W,Zr)B2-(Hf,Ta,Ti,W,Zr)C high entropy ultra-high temperature ceramics were processed from commercial diboride and carbide powders with and without SiC additions. A 30-min hold at a maximum temperature of 1850 °C in spark plasma sintering resulted in a relative density of ∼95 %, which increased to ∼100 % with the addition of 7.5 wt.% SiC. The compositions did not reach chemical equilibrium under the given sintering conditions resulting in an inhomogeneous distribution of transition metals in both the boride and carbide phases. The addition of SiC improved densification by inhibiting grain growth, which reduced the grain size from 9.0 ± …


Magnetic Separation Of Lunar Regolith Simulants With Applications To In Situ Resource Utilization On The Moon, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han Jan 2024

Magnetic Separation Of Lunar Regolith Simulants With Applications To In Situ Resource Utilization On The Moon, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

The development of in situ resource utilization (ISRU) for metal extraction is imperative as a steppingstone for habitation construction in lunar and non-terrestrial environments. Separation of minerals by chemical composition is important to optimize metal and oxygen liberation from lunar ore. to this effect, devices capable of separating aluminum bearing minerals from iron-bearing minerals from the lunar regolith simulants have been developed. Twenty-eight different simulants have been used in this study. a dual-belt separator was designed to reduce middlings. Para-magnetic minerals were reliably separated using a neodymium N52-magnet-separator system. Effective separation of aluminum-bearing minerals from iron-bearing minerals was greater than …


Beneficiation Of Lunar Regolith Simulants Through Electrostatic Sieving And Magnetic Separation, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han Jan 2024

Beneficiation Of Lunar Regolith Simulants Through Electrostatic Sieving And Magnetic Separation, Peter Bachle, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

In the light of future development of lunar structures, in-situ feldspar beneficiation is imperative for metal extraction. This research incorporates the tandem use of electrostatic sieving and magnetic separation for collecting a specific size range and mineral composition from lunar soil that optimizes subsequent chemical processing. While earlier works focused on silt-sized particles, this work expands that range up to medium-grained sand with a greater variety of potential lunar regolith compositions. This work shows that a 2.5 kV, 7 Hz to 30Hz frequency, single-phase square wave can lift silt and fine sand for collection. This lifting is successful directly from …


Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies, Easton Ingram, Emmanuela Amen Eze, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han Jan 2024

Kinetic Modeling Of Electrostatic Sieving For Lunar Regolith Beneficiation: Case Studies, Easton Ingram, Emmanuela Amen Eze, Jeffrey Smith, Fateme Rezaei, David Bayless, William Schonberg, Daoru Han

Materials Science and Engineering Faculty Research & Creative Works

A new kinetic particle modeling framework was developed to investigate electrostatic transport of lunar regolith particles with applications to the concept of electrostatic sieving. The new approach is based on kinetic particle dynamics and includes major modules of sampling the particle size distribution, solving electric fields, and tracking motion of charged dust grains. Case studies for a concept of electrostatic sieving were chosen to validate the new model. The simulation achieved similar yields reported in previous works, which served as validation of the model. The new model is computationally efficient and could serve as a design, analysis, and optimization tool.


Development Of A Highly Loaded Zirconium Carbide Paste For Material Extrusion Additive Manufacturing, Clare Sabata, Austin J. Martin, Jeremy L. Watts, Gregory E. Hilmas Jan 2024

Development Of A Highly Loaded Zirconium Carbide Paste For Material Extrusion Additive Manufacturing, Clare Sabata, Austin J. Martin, Jeremy L. Watts, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

A highly loaded, aqueous-based zirconium carbide (ZrC) paste was developed for ceramic on-demand extrusion (CODE). Commercial ZrC powder was ball milled to reduce the particle size to ∼1 μm. Paste composition was determined by rheological characterization and observation of printing behavior; the final paste consisted of 46–47 vol% ZrC, 43.5 vol% distilled water, 8.1 vol% dispersant, and 1.6 vol% binder. Rheological characterization of the paste showed a yield stress of ∼8 Pa and shear thinning behavior (ΔG′/Δσ* = −55). The paste was printed using a 610 μm nozzle; a test print showed shape fidelity using the developed paste. A pressureless …


Effect Of Sc Spatial Distribution On The Electronic And Ferroelectric Properties Of Alscn, Bipin Bhattarai, Xiaoman Zhang, Wangwang Xu, Yijia Gu, W. J. Meng, Andrew C. Meng Jan 2024

Effect Of Sc Spatial Distribution On The Electronic And Ferroelectric Properties Of Alscn, Bipin Bhattarai, Xiaoman Zhang, Wangwang Xu, Yijia Gu, W. J. Meng, Andrew C. Meng

Materials Science and Engineering Faculty Research & Creative Works

While aluminum scandium nitride based ferroelectric materials have shown significant promise for non-volatile memory applications, difficulties relating challenges in device performance, such as electrical leakage, to structural characteristics motivate improved understanding of the fundamental structure-property relationship. Spinodal decomposition has been reported in this material system, consistent with our observation of compositional segregation in AlScN films grown by reactive sputter epitaxy. To better understand the effects of spatially non-uniform Sc concentrations, the electronic and ferroelectric (FE) properties of AlScN as a function of Sc distribution are studied using density functional theory (DFT). We explore the impact of Sc-rich atomic planes in …


Phenolic Polymer Infiltration And Pyrolysis Process For Additively Manufactured Carbon/Peek Composites To Produce Carbon–Carbon Composites, S. Weiler, H. A. Haffner, K. Chandrashekhara, J. Watts, G. E. Hilmas, J. Bayldon, L. M. Rueschhoff Jan 2024

Phenolic Polymer Infiltration And Pyrolysis Process For Additively Manufactured Carbon/Peek Composites To Produce Carbon–Carbon Composites, S. Weiler, H. A. Haffner, K. Chandrashekhara, J. Watts, G. E. Hilmas, J. Bayldon, L. M. Rueschhoff

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Carbon–carbon composites are carbon fibers reinforced with carbon matrix and are classified as advanced materials well suited for high-temperature structural applications. Carbon–carbon composites are characterized by maintaining excellent mechanical properties and structural stability at high temperatures and have been used in aerospace application as nozzles, heatshields, and leading edge. However, conventional methods to manufacture carbon–carbon composites are costly and time-consuming. the aim of this work is to develop a method for creating additively manufactured (AM) carbon–carbon composites using a high-pressure re-infiltration process. in doing so, less infiltration cycles are required compared to a low-pressure re-infiltration, reducing the total manufacture time. …


Damage Initiation Of 15v38 Steel Bar During Square-To-Round Hot Rolling Process, Siva Sai Krishna Dasari, Henry Adekola Haffner, K. Chandrashekhara, Mario F. Buchley, Simon N. Lekakh, Ronald J. O'Malley Jan 2024

Damage Initiation Of 15v38 Steel Bar During Square-To-Round Hot Rolling Process, Siva Sai Krishna Dasari, Henry Adekola Haffner, K. Chandrashekhara, Mario F. Buchley, Simon N. Lekakh, Ronald J. O'Malley

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Hot rolling processes have been extensively used to produce round bars by reducing the cross-sectional area of continuously cast steel. The current trend toward increasing productivity often requires a more aggressive reduction per pass. Establishing safe and optimized hot rolling parameters must be determined to avoid damage while deforming the specific steel composition. Understanding the damage mechanism during the metal forming process is vital for product quality. Herein, a combined experimental and simulation approach is developed to track the evolution potential damage during hot bar rolling. Hot tension tests are conducted on as-cast vanadium micro alloyed 15V38 steel at different …


Thermodynamic Analysis Of Metal Segregation In Dual Phase High Entropy Ceramics, Steven M. Smith, William G. Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo Jan 2024

Thermodynamic Analysis Of Metal Segregation In Dual Phase High Entropy Ceramics, Steven M. Smith, William G. Fahrenholtz, Gregory E. Hilmas, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Equilibrium Gibbs' free energy calculations were used to determine metal segregation trends between boride and carbide solid solutions containing two metals that are relevant to dual phase high entropy ceramics. The model predicted that Ti had the strongest tendency to segregate to the boride phase followed by Zr, Nb, Mo, V, Hf, and Ta, which matches experimental results of measured compositions. The ratio of a metal in the carbide phase to the content of the same metal in the corresponding metal boride had a linear trend with the change in standard Gibbs' free energy of reaction for a metal carbide …


A Super-Hard High Entropy Boride Containing Hf, Mo, Ti, V, And W, Suzana Filipovic, Nina Obradovic, Greg E. Hilmas, William G. Fahrenholtz, Donald W. Brenner, Jon Paul Maria, Douglas E. Wolfe, Eva Zurek, Xiomara Campilongo, Stefano Curtarolo Jan 2024

A Super-Hard High Entropy Boride Containing Hf, Mo, Ti, V, And W, Suzana Filipovic, Nina Obradovic, Greg E. Hilmas, William G. Fahrenholtz, Donald W. Brenner, Jon Paul Maria, Douglas E. Wolfe, Eva Zurek, Xiomara Campilongo, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Super-Hard (Hf,Mo,Ti,V,W)B2 Was Synthesized by Boro-Carbothermal Reduction and Densified by Spark Plasma Sintering. This Composition Was Produced for the First Time as a Single-Phase Ceramic in the Present Research. the Optimized Ceramic Had a Single Hexagonal AlB2-Type Crystalline Phase with a Grain Size of 3.8 µm and Homogeneous Distribution of the Constituent Metals. the Vickers Hardness Exhibited the Indentation Size Effect, Increasing from 27 GPa at a Load of 9.8 N to as High as 66 GPa at a Load of 0.49 N. This is the Highest Hardness Reported to Date for High Entropy Boride Ceramics.


Oxidation Of Additively Manufactured Zrb2–Sic In Air And In Co2 At 700–1000 °C, Marharyta Lakusta, Nicholas M. Timme, Abid H. Rafi, Jeremy Lee Watts, M. (Ming) C. (Chuan) Leu, Gregory E. Hilmas, William G. Fahrenholtz, David W. Lipke Jan 2024

Oxidation Of Additively Manufactured Zrb2–Sic In Air And In Co2 At 700–1000 °C, Marharyta Lakusta, Nicholas M. Timme, Abid H. Rafi, Jeremy Lee Watts, M. (Ming) C. (Chuan) Leu, Gregory E. Hilmas, William G. Fahrenholtz, David W. Lipke

Materials Science and Engineering Faculty Research & Creative Works

Oxidation behavior of additively manufactured zrb2–sic in air and in co2 is reported in the temperature range of 700–1000 °c. Observed scale morphologies in air and in co2 were similar, featuring an outer borosilicate layer and an inner porous zirconia layer containing partially oxidized silicon carbide particles and remnant borosilicate products. Oxide scale thicknesses and parabolic scaling constants in air were approximately twice those observed in co2 across all studied temperatures. Activation energies for oxidation of 140 ± 20 kj/mol in air and 110 ± 20 kj/mol in co2 were determined, indicating similar diffusion processes that appear to be rate-limiting. …


A Multi-Life Cycle Assessment Of External Wall Insulation Strategies In An Irish Domestic Retrofit, Sara Carrigan, Patrick Daly, Alberta Congeduti Jan 2024

A Multi-Life Cycle Assessment Of External Wall Insulation Strategies In An Irish Domestic Retrofit, Sara Carrigan, Patrick Daly, Alberta Congeduti

Articles

European Union (EU) policy and initiatives are driving both building renovation and the uptake of low-embodied carbon and circular design in the construction sector. The European Performance of Buildings Directive (EPBD) recast (2021) introduces global warming potential (GWP) methodology, and the future state will likely be embodied carbon targets for which life cycle assessment (LCA) of buildings will be required. External wall insulation (EWI) will have an important role to play in meeting targets. In this context, this paper compares the carbon emission payoff of three alternative EWI strategies that address conventional, low-carbon and circular solutions to EWI respectively, in …


Minerrouter : Effective Message Routing Using Contact-Graphs And Location Prediction In Underground Mine, Abhay Goyal, Sanjay Madria, Samuel Frimpong Jan 2024

Minerrouter : Effective Message Routing Using Contact-Graphs And Location Prediction In Underground Mine, Abhay Goyal, Sanjay Madria, Samuel Frimpong

Computer Science Faculty Research & Creative Works

Location-based distributed communication in underground mines has been a hard problem to solve due to unreliable centralized architecture such as leaky feeder systems, high attenuation, and the unavailability of GPS signals. Delay Tolerant Networks (DTN) enable decentralized message routing using the store-carry-forward method that can help in creating situational awareness needed to handle emergency and disaster scenarios. The ability to predict where the DTN nodes (miner) might have been at/are headed to (with respect to the mine regions and pillars) at different times, combined with contact-based routing and intelligent handling of buffer, can be used for better delivery of messages. …


Evaluation Of Novel Preformed Particle Gel System For Conformance Control In Mature Oil Reservoirs, Abdulaziz Almakimi, Ahmed Ben Ali, Ibnelwaleed A. Hussein, Baojun Bai Jan 2024

Evaluation Of Novel Preformed Particle Gel System For Conformance Control In Mature Oil Reservoirs, Abdulaziz Almakimi, Ahmed Ben Ali, Ibnelwaleed A. Hussein, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To address challenges associated with excessive water production in mature oil reservoirs, this study introduces a carboxymethyl cellulose (CMC)-based material as a novel preformed particle gel (PPG) designed to plug excessive water pathways and redistribute the subsequent injected water toward unswept zones. Through microwave-assisted grafting copolymerization of CMC with acrylamide (AM), we successfully generated multi-sized dry particles within the range of 250–800 µm. Comprehensive analyses, including Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), have confirmed the chemical composition and morphology of the resulting carboxymethyl cellulose-grafted crosslinked polyacrylamide (CMC/PAMBA). Swelling kinetics and rheology tests were conducted to confirm the …


Additive Manufacturing Of Novel Lightweight Insulation Refractory With Hierarchical Pore Structures By Direct Ink Writing, Saisai Li, Jiaxuan Xin, Ruoyu Chen, Haiming Wen Jan 2024

Additive Manufacturing Of Novel Lightweight Insulation Refractory With Hierarchical Pore Structures By Direct Ink Writing, Saisai Li, Jiaxuan Xin, Ruoyu Chen, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

A direct ink writing process using fly ash foaming slurries was employed for the additive manufacturing of lightweight mullite insulation refractory with hierarchical pore structures. The viscosity, thixotropy, and shear thinning behavior of the inks were analyzed to investigate the effect of the inorganic binder and dispersant of the foaming inks. A slurry exhibiting excellent rheological characteristics was identified, consisting of 45 wt% fly ash floating beads, 55 wt% water, 3.0 wt% additional dispersant, and 6.0 wt% additional binder. Furthermore, through the optimization of printing parameters such as printing pressure and printing speed, notable enhancements were achieved in the pore …


Morphology And Particle Size (Maps) Exercise: Testing The Applications Of Image Analysis And Morphology Descriptions For Nuclear Forensics, Stuart A. Dunn, Ian J. Schwerdt, David E. Meier, Naomi E. Marks, Thomas Shaw, Alexa Hanson, Kari Sentz, Meena Said, Richard A. Clark, Kyle A. Makovsky, Jason M. Lonergan, Matthew Gilbert Jan 2024

Morphology And Particle Size (Maps) Exercise: Testing The Applications Of Image Analysis And Morphology Descriptions For Nuclear Forensics, Stuart A. Dunn, Ian J. Schwerdt, David E. Meier, Naomi E. Marks, Thomas Shaw, Alexa Hanson, Kari Sentz, Meena Said, Richard A. Clark, Kyle A. Makovsky, Jason M. Lonergan, Matthew Gilbert

Materials Science and Engineering Faculty Research & Creative Works

Image analysis techniques have been applied and shown to be a valuable tool in nuclear forensics analysis. The interlaboratory exercise reported here has tested quantitative and qualitative approaches for characterizing nuclear materials. Particle size, surface features and morphology descriptions were compared by four laboratories on a common image set generated by Scanning Electron Microscopy and Digital Light Microscopy. Quantitative analysis of the image sets through the Morphological Analysis for Materials software highlighted the strength of image analysis, but also that the application of the software alone can introduce significant bias in the analysis. Qualitative morphology descriptions following the process outlined …


Ring Opening Functionalization Of Thiolactone Homopolymers For Ros Scavenging, Aaron Priester, Forrest Kievit, Anthony J. Convertine Jan 2024

Ring Opening Functionalization Of Thiolactone Homopolymers For Ros Scavenging, Aaron Priester, Forrest Kievit, Anthony J. Convertine

Materials Science and Engineering Faculty Research & Creative Works

In This Research, We Explored the Synthesis and Application of Thiolactone Acrylamide (TLA) Polymers for Neutralizing Reactive Oxygen Species (ROS), Produced as a Result of Traumatic Brain Injury (TBI). We Synthesized Well-Defined TLA Polymers using RAFT (Reversible Addition-Fragmentation Chain Transfer) Polymerization Across a Range of Monomer-To-Chain Transfer Agent ([M]0/[CTA]0) Ratios to Achieve a Range of Molar Masses. Polymerizations Were Carried Out using a Trithiocarbonate CTA (Chain Transfer Agent) with AIBN (Azobisisobutyronitrile) as the Initiator in N'N-Dimethylacetamide (DMAc) at 60 °C. Kinetic Studies Indicated a Linear Increase in Molar Mass with Conversion, Pseudo-First-Order Kinetics, and Molar Mass Values that Are Consistent …


The Mechanism And Effect Of Seismic Source Location Using Double Waves In Three-Dimensional Microseismic Monitoring, Zhigang Wang, Xiaoqing Wang, Shunlin Yin, Maochen Ge Jan 2024

The Mechanism And Effect Of Seismic Source Location Using Double Waves In Three-Dimensional Microseismic Monitoring, Zhigang Wang, Xiaoqing Wang, Shunlin Yin, Maochen Ge

Mining Engineering Faculty Research & Creative Works

Accurate seismic source location has always been the most important purpose of micro seismic and seismic monitoring. The location accuracy inside the existing monitoring networks is generally high, whereas the accuracy in the external area and sensor accessories area tends to be low. This scenario contributes to an overall limitation in the effective monitoring area. The seismic source location was performed in this study using P waves and S waves to improve the location accuracy outside the monitoring networks and in the adjacent area and enlarge the high-accuracy control area of the monitoring networks. Moreover, the mechanism of seismic source …


Spatiotemporal Variance Image Reconstruction For Thermographic Inspections, Logan M. Wilcox, Emily M. Johnson, Emma T. Bohannon, Catherine E. Johnson, Kristen M. Donnell Jan 2024

Spatiotemporal Variance Image Reconstruction For Thermographic Inspections, Logan M. Wilcox, Emily M. Johnson, Emma T. Bohannon, Catherine E. Johnson, Kristen M. Donnell

Mining Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is a nondestructive testing and evaluation (NDT&E) technique that utilizes a radiating antenna to induce a thermal increase on or within a specimen under test (SUT). The radiated power density is spatially nonuniform and therefore results in a spatially nonuniform thermal excitation, which may result in missed or false indications of defects. To this end, this work proposes a novel image reconstruction technique for nonuniform excitation/heating and is referred to as Spatiotemporal Variance Reconstruction (STVR). STVR utilizes the spatial and temporal variance of the surface thermal profile. STVR is advantageous in that it does not require …


Generation Of Micro-Fracture Clouds In Rocks: Mechanisms And Applications, U. Mutlu, G. Boitnott, A. Lisjak, O. Mahabadi, Taghi Sherizadeh, D. Guner, S. Nowak, A. Ghassemi Jan 2024

Generation Of Micro-Fracture Clouds In Rocks: Mechanisms And Applications, U. Mutlu, G. Boitnott, A. Lisjak, O. Mahabadi, Taghi Sherizadeh, D. Guner, S. Nowak, A. Ghassemi

Mining Engineering Faculty Research & Creative Works

Volume increasing or decreasing processes in rocks can lead to inter or intragranular fractures in subsurface formations. The volume change can be caused by chemical reactions involving fluid, reactive transport, and coupling with the mechanical deformation of the grains. Depending on stress, material properties and coupled thermo-hydro-mechanical-chemical (THMC) conditions, grain scale fractures may propagate and coalesce, forming a cloud of well-connected fracture networks. The mechanisms responsible for propagation, coalescence and inhibition of cloud fractures are not well known. In this study, we review coupled micro-fracture network generation mechanisms as published in the literature and observed in field, experiments, and models. …


Fluorescent Security Glass, Rachel Leigh Grodsky, Richard Brow, Melissa Malone-Teague Jan 2024

Fluorescent Security Glass, Rachel Leigh Grodsky, Richard Brow, Melissa Malone-Teague

Patents

A tamper-evident glass and methods of using the tamperevident glass are provided herein. The tamper-evident glass comprising at least a first plurality of tamper-evident elements, which may be unique or near unique to each manufacturing of tam per-evident glass. The initial state of tamper-evident glass and positioning of the plurality of tamper-evident elements may be mapped through digital scanning to create a digital file of the current state of the tamper-evident glass. The tamper-evident glass may be scanned again to create a new digital file for comparison and to determine if a tampering event has occurred. The tamperevident elements may …


Electrical Connectors Including Glass Seals And Methods Of Fabrication, Dennis J. Eichorst, Tieshu Huang, Kaley M. Mclain, Richard K. Brow Jan 2024

Electrical Connectors Including Glass Seals And Methods Of Fabrication, Dennis J. Eichorst, Tieshu Huang, Kaley M. Mclain, Richard K. Brow

Patents

An electrical connector comprises an outer shell, at least one pin, and an insulating seal. The outer shell includes at least one side wall defining a cavity and having an inner surface. The outer shell is formed from electrically conductive material. The pin is positioned within the cavity and is also formed from electrically conductive material. The insulating seal is configured to provide electrical isolation of the pin and fills the cavity between the inner surface of the side wall and the pin. The insulating seal is formed from glass doped with a transition metal oxide.


Miniature 3d Position-To-Optical Displacement Sensor, Genda Chen, Jie Gao, Chuanrui Guo Jan 2024

Miniature 3d Position-To-Optical Displacement Sensor, Genda Chen, Jie Gao, Chuanrui Guo

Patents

A miniature, micrometer-accuracy, three-dimensional (3D) position-to-optical displacement sensor that has at least one extrinsic Fabry-Perot interferometer (EFPI) in Z direction and a series of plasmonic metasurface resonators with distinctive wavelength-selective characteristics in X and Y directions. The interferometer comprises at least one single mode optic fiber for light propagation, and a substrate mirror to create a light interference fringe as a function of distance between the mirror and the distal end of the optic fiber. Each plasmonic resonator is capable of modifying the substrate mirror and comprises an array of multiple unit nanostructure unit cells that are arranged in a …