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Articles 361 - 390 of 21777

Full-Text Articles in Engineering

Effects Of Wc Additions On The Phase Formation Of (Hf,Nb,Ta,Ti,Zr)C-(Hf,Nb,Ta,Ti,Zr)B2 High Entropy Dual Phase Ceramics, Rubia Hassan, William G. Fahrenholtz, Gregory E. Hilmas Dec 2025

Effects Of Wc Additions On The Phase Formation Of (Hf,Nb,Ta,Ti,Zr)C-(Hf,Nb,Ta,Ti,Zr)B2 High Entropy Dual Phase Ceramics, Rubia Hassan, William G. Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

High entropy dual phase (Hf,Nb,Ta,Ti,Zr)C-(Hf,Nb,Ta,Ti,Zr)B2 ultra-high temperature ceramics were produced from powders synthesized by boro-carbothermal reduction. Systematic additions of 2.5 wt%, 5 wt%, and 10 wt% WC were incorporated after powder synthesis. Additions of 2.5 wt% and 5 wt% WC dissolved into the host ceramics, resulting in complete solid solution formation and nearly full densification. In contrast, a secondary monoboride phase evolved for the composition with 10 wt% WC, in addition to the main high entropy carbide and diboride phases. Thermodynamic analysis revealed that WB formation was favorable for WC additions in the presence of metal diborides at the sintering …


Micro/Nanomechanical Properties Of Top-Seeded Melt Grown Ybco Single Crystals Determined Using Depth Sensing Indentation, Ugur Kolemen, Cafer Mert Yesilkanat, Fikret Yilmaz, Fatih Dogan, Orhan Uzun Dec 2025

Micro/Nanomechanical Properties Of Top-Seeded Melt Grown Ybco Single Crystals Determined Using Depth Sensing Indentation, Ugur Kolemen, Cafer Mert Yesilkanat, Fikret Yilmaz, Fatih Dogan, Orhan Uzun

Materials Science and Engineering Faculty Research & Creative Works

Mechanical properties of the bulk YBa2Cu3O7-x (YBCO) single crystal superconductor, prepared by using the Top Seeded Melt Growth (TSMG) method, were determined. Property measurements were conducted by the nanoindentation method under various loads and the micro indentation method at different temperatures. Hardness (H) and reduced elastic modulus (Er) values were calculated by using the Oliver–Pharr method. According to hf/h max values found from load- displacement curves, there is a sink in behavior around outer rim of the indents that was confirmed by atomic force microscopy (AFM) analysis. Nanoindentation analyses conducted on upper section, middle section and subsection revealed that all …


Effect Of Powder Recycling On Powder Characteristics And Mechanical Properties Of Materials Produced By Laser Powder Bed Fusion (Lpbf): A Review, Mihiretu Ganta, Marta Kurek, Arezoo Emdadi, Tadeusz Łagoda, Marek Pagáč Dec 2025

Effect Of Powder Recycling On Powder Characteristics And Mechanical Properties Of Materials Produced By Laser Powder Bed Fusion (Lpbf): A Review, Mihiretu Ganta, Marta Kurek, Arezoo Emdadi, Tadeusz Łagoda, Marek Pagáč

Materials Science and Engineering Faculty Research & Creative Works

As the Laser powder bed fusion (LPBF) process advances toward industrial-scale production, the sustainability of metal powder feedstocks has become a focal point of research. The powder recycling approach, while environmentally and economically favorable, results in a series of physicochemical variations that could compromise the part quality. The resulting variation in powder characteristics with powder recycling could affect the powder layer density and melt pool dynamics, resulting in defect formation and hindering the structural integrity of LPBFed parts. These alterations pose significant constraints to mechanical performance, particularly in fatigue-sensitive applications where even minor imperfections can substantially reduce service life. The …


Variable-Temperature Plasmonic High-Entropy Carbides, Simon Divilov, Sean D. Griesemer, Robert C. Koennecker, Michael J. Ammendola, Adam C. Zettel, Hagen Eckert, Jeffrey R. Shallenberger, Xiomara Campilongo, William G. Fahrenholtz, Arrigo Calzolari, Douglas E. Wolfe, Stefano Curtarolo Dec 2025

Variable-Temperature Plasmonic High-Entropy Carbides, Simon Divilov, Sean D. Griesemer, Robert C. Koennecker, Michael J. Ammendola, Adam C. Zettel, Hagen Eckert, Jeffrey R. Shallenberger, Xiomara Campilongo, William G. Fahrenholtz, Arrigo Calzolari, Douglas E. Wolfe, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Effective thermal management at variable and extreme temperatures face limitations for the development of novel energy and aerospace applications. Plasmonic approaches, shown to be capable of tailoring black-body emission, could be effective if materials with high-temperature and tunable plasmonic resonance were available. Here, we report a synergy between experimental and theoretical results proving that many high-entropy transition metal carbides, consisting of four or more metals at equal molar ratio, have plasmonic resonance at room, high (>1000∘C) and variable temperatures. We also found that these high-entropy carbides can be tuned and show considerable plasmonic thermal cycling stability. This paradigm-shift approach …


A Precipitation-Hardened High-Entropy Alloy With Excellent Mechanical Properties Additively Manufactured By In-Situ Alloying, Matthew Luebbe, Shahryar Mooraj, Jonathan Poplawsky, Hans Pommerenke, Wen Chen, Haiming Wen Dec 2025

A Precipitation-Hardened High-Entropy Alloy With Excellent Mechanical Properties Additively Manufactured By In-Situ Alloying, Matthew Luebbe, Shahryar Mooraj, Jonathan Poplawsky, Hans Pommerenke, Wen Chen, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Studies on precipitation-hardened high-entropy alloys (PHEAs) have demonstrated high strength, good ductility, and thermal stability, making them excellent candidates for high-temperature structural applications such as nuclear reactors. However, many complex parts for those applications would need to be produced via additive manufacturing (AM), whose rapid cooling rates and multiple heating cycles could change the microstructure of the chosen alloys and accordingly their mechanical properties. A PHEA, (Fe0.3Ni0.3Mn0.3Cr0.1)88Ti4Al8, which was developed and produced via conventional manufacturing in our previous work with high strength but low ductility, was chosen to test the effects of AM on the microstructure and mechanical properties. Scanning …


Experimental Determination Of Tnt Equivalence Values For Binary Energetic Materials, Gracie May M. James, Rachel L. Bauer, Emily M. Johnson, Catherine E. Johnson Dec 2025

Experimental Determination Of Tnt Equivalence Values For Binary Energetic Materials, Gracie May M. James, Rachel L. Bauer, Emily M. Johnson, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

TNT equivalency quantifies the impact of energetic materials relative to TNT, aiding in safety guidelines and performance evaluations. Despite widespread use in industry, military, and research, many binary energetics lack published TNT equivalence values. This study experimentally determines TNT equivalency values for Helix, Texpak, Rimfire, Tannerite, and Kinepak using three tests: (1) plate dent, (2) reaction velocity and (3) air blast. Each test evaluates distinct aspects of energetic performance, addressing both close-in destructive power and downstream effects. Helix produced TNT equivalence values from 0.64 to 1.10, comparable to TNT, while Kinepak had lower values (0.18 to 0.58) indicating limited brisance, …


Data Driven Design Of Ultra High Performance Concrete Prospects And Application, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Jie Huang, Ashutosh Goel, Aditya Kumar, Narayanan Neithalath Dec 2025

Data Driven Design Of Ultra High Performance Concrete Prospects And Application, Bryan K. Aylas-Paredes, Taihao Han, Advaith Neithalath, Jie Huang, Ashutosh Goel, Aditya Kumar, Narayanan Neithalath

Electrical and Computer Engineering Faculty Research & Creative Works

Ultra-high-performance concrete (UHPC) is a specialized class of cementitious composites that is increasingly used in various applications, including bridge decks, connections between precast components, piers, columns, overlays, and the repair and strengthening of bridge elements. The mechanical and durability properties of UHPC are significantly influenced by factors such as low water-to-binder ratios, the inclusion of supplementary cementitious materials (SCMs), and fiber reinforcement. Machine learning (ML) has been employed to predict the performance of UHPC and optimize its mixture designs by using various raw materials. This study first provides a comprehensive review of ML applications in UHPC, focusing on predicting workability, …


Fluorosilane-Induced Softening And Collapse Of Micropillar Arrays, Gabriela Moreira Lana, Maja Fehlberg, Petra Herbeck-Engel, Gisela Heppe, Raimund Schlüßler, Torsten Jähnke, Eduard Arzt, Roland Bennewitz Nov 2025

Fluorosilane-Induced Softening And Collapse Of Micropillar Arrays, Gabriela Moreira Lana, Maja Fehlberg, Petra Herbeck-Engel, Gisela Heppe, Raimund Schlüßler, Torsten Jähnke, Eduard Arzt, Roland Bennewitz

Chemical and Biochemical Engineering Faculty Research & Creative Works

Replica molding is a widely used technique for the fabrication of polymer microstructures. As structural dimensions decrease, anti-stick surface treatment of the mold becomes increasingly critical to ensure clean demolding and preserve structural integrity. We fabricated arrays of micropillars with 20 µm diameter and 60 µm height using medical-grade polydimethylsiloxane (PDMS), MDX4-4210, and observed a high fraction of collapsed pillars for the first molding after fluorosilanization of the mold to reduce sticking. To address this issue, we systematically investigated the surface treatment protocol for the molds, made from the PDMS Sylgard 184. We provide results from complementary measurement methods, to …


Synergistic Doping And Coating Strategy For Boosting Na0.7mno2 Cathode Performance In Sodium-Ion Batteries, Ahmad Helaley, Han Yu, Manashi Nath, Xinhua Liang Nov 2025

Synergistic Doping And Coating Strategy For Boosting Na0.7mno2 Cathode Performance In Sodium-Ion Batteries, Ahmad Helaley, Han Yu, Manashi Nath, Xinhua Liang

Chemistry Faculty Research & Creative Works

Advancing sodium-ion battery (SIB) technology requires novel approaches to optimize cathode materials for improved electrochemical performance. In this study, we employ atomic layer deposition (ALD) to precisely modify the surface of P2-type Na0.7MnO2 cathodes with different coating materials including ZnO, NiO, and Al2O3, followed by post-annealing at 750°C for 10 hours. The strategic combination of ALD and thermal treatment can achieve thin film coating on particle surface and promote element doping into the near-surface lattice, as confirmed by electron energy loss spectroscopy (EELS) analysis. The incorporation of Zn, Al, and Ni results in …


Comparative Study Of Interfacial Bond Strength Of Steel H-Pile With Ultra-High Performance And Polymer Concrete Jacket, Binod Shrestha, Mohanad M. Abdulazeez, Mohamed A. Elgawady Nov 2025

Comparative Study Of Interfacial Bond Strength Of Steel H-Pile With Ultra-High Performance And Polymer Concrete Jacket, Binod Shrestha, Mohanad M. Abdulazeez, Mohamed A. Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the bond behavior of steel H-pile encased in concrete jackets under push-out loading, considering the effects of concrete type and embedment length. Nine full-scale specimens were tested using three concrete types: ultra-high-performance concrete (UHPC), Methyl Methacrylate Polymer Concrete (MMA-PC), and conventional concrete (CC), with embedment lengths of 63.5 mm, 127 mm, and 190.5 mm. The experimental results revealed that MMA-PC jacket demonstrated the highest bond strength, though gains were marginal beyond 127 mm. UHPC exhibited superior tensile strength and ductility, preventing splitting failure. UHPC also displayed the highest interfacial fracture energy of 9.63 N/mm, exceeding MMA-PC and …


Treatment Intensification Of Digester Dewatering Sidestreams Via Pilot- And Demonstration-Scale Revolving Algal Biofilms At Municipal Water Resource Recovery Facilities, Audrey E. Kocher, Hunter W. Schroer, Christopher A. Marks, Craig L. Just Nov 2025

Treatment Intensification Of Digester Dewatering Sidestreams Via Pilot- And Demonstration-Scale Revolving Algal Biofilms At Municipal Water Resource Recovery Facilities, Audrey E. Kocher, Hunter W. Schroer, Christopher A. Marks, Craig L. Just

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

As water resource recovery facilities (WRRFs) pursue decarbonization, the treatment of concentrated side streams from anaerobic digestion offers a critical opportunity to reduce energy use and greenhouse gas emissions. This study evaluated the intensification potential of revolving algal biofilms (RAB) for side stream nutrient removal via partial nitrification at pilot- and demonstration-scales. RAB systems were deployed at municipal WRRFs in Boulder and Iowa City, treating real dewatering side streams across a range of ammonium (NH4+–N) surface area loading rates (SALR) reaching up to 196 g N m–2d–2. The results demonstrated that RAB systems can …


Elucidating The Effects Of Water Activity On The Hydration Kinetics And Thermodynamics Of Ye’Elimite–Calcium Sulfate Hydrate Systems, Godwin I. Ogbuehi, Rupack R. Halder, Aditya Kumar, Gaurav Sant, Monday U. Okoronkwo Nov 2025

Elucidating The Effects Of Water Activity On The Hydration Kinetics And Thermodynamics Of Ye’Elimite–Calcium Sulfate Hydrate Systems, Godwin I. Ogbuehi, Rupack R. Halder, Aditya Kumar, Gaurav Sant, Monday U. Okoronkwo

Materials Science and Engineering Faculty Research & Creative Works

Relative humidity and water activity (aH) reductions have been known to suppress the hydration of anhydrous cement clinker phases. However, the relationship between ye'elimite (C4A3$) hydration kinetics and water activity remain unclear. This study employs experimental and thermodynamic modeling approaches to investigate the influence of water activity on ye'elimite hydration in the "C4A3$ + water", and "C4A3$ + gypsum + water" systems. Experimental findings indicate that as water activity decreases, C4A3$ hydration diminishes until the reaction is brought to a halt at a threshold aH. The critical aHand corresponding solubility constant of C4A3$ (KC4A3S¯) estimated from thermodynamic analysis are 0.46 …


Effects Of Yttrium And Barium Trace Impurities On The Dielectric Properties Of  Srtio3 (111) Single Crystals At Cryogenic Temperatures, Hung Trinh, Alan Devoe, Fatih Dogan Nov 2025

Effects Of Yttrium And Barium Trace Impurities On The Dielectric Properties Of  Srtio3 (111) Single Crystals At Cryogenic Temperatures, Hung Trinh, Alan Devoe, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Commercially available single crystals of (111) SrTiO3 were found to contain impurities of varying amounts that strongly affected their dielectric performance at cryogenic temperatures. Three crystals with total impurities of 111, 126, and 625 ppm, primarily of barium and yttrium, were analyzed. Relative permittivity (εr) and loss tangent were investigated with high resolution as a function of temperature (4 K to 100 K), DC voltage (0 V/cm to 800 V/cm), and frequency (100 Hz to 1 MHz). An impurity level as low as ≈500 ppm barium resulted in an increase of the maximum permittivity (εm) to approximately 50,000 at …


Energy-Harvesting Concurrent Lora Mesh With Timing Offsets For Underground Mine Emergency Communications, Hilary Kelechi Anabi, Samuel Frimpong, Sanjay Madria Nov 2025

Energy-Harvesting Concurrent Lora Mesh With Timing Offsets For Underground Mine Emergency Communications, Hilary Kelechi Anabi, Samuel Frimpong, Sanjay Madria

Mining Engineering Faculty Research & Creative Works

Underground mine emergencies destroy communication infrastructure when situational awareness is most critical. Current systems rely on centralized network infrastructure, which fails during emergencies when miners are trapped and require rescue coordination. This paper proposes an energy-harvesting LoRa mesh network that addresses self-powered operation, interference management, and adaptive physical layer optimization under severe underground propagation conditions. A dual-antenna architecture separates RF energy harvesting (860 MHz) from LoRa communication (915 MHz), enabling continuous operation with supercapacitor storage. The core contribution is a decentralized scheduler that derives optimal timing offsets by modeling concurrent transmissions as a Poisson collision process, exploiting LoRa's capture effect …


A Comprehensive Overview Of Chronic Wound Infections And Current Treatment Methods, Sarah Fakher, David J. Westenberg Nov 2025

A Comprehensive Overview Of Chronic Wound Infections And Current Treatment Methods, Sarah Fakher, David J. Westenberg

Biological Sciences Faculty Research & Creative Works

Chronic wound infections pose significant healthcare challenges due to persistent biofilms, antibiotic resistance, and impaired healing pathways. These wounds are characterized by prolonged inflammation, microbial colonization, and disrupted tissue regeneration, leading to substantial morbidity and healthcare costs. This article reviews current knowledge on chronic wound types, their pathophysiology, and the mechanisms underlying biofilm formation to examine the latest advancements in antimicrobial-based strategies aimed at addressing these challenges. It highlights how diverse materials and technologies have been engineered to improve infection management, enhance tissue regeneration, and overcome the limitations of traditional treatments as well as advances that leverage innovations such as …


Enhanced The Simultaneous Recovery/Extraction Of Combined Heavy Metals Of Lead And Vanadium From Synthetic Wastewater Using An Emulsion Liquid Membrane (Elm) With Nanoparticles And Ionic Liquid, Qusay Al-Obaidi, Nora Yehia Selem, Oumaima Karai, Kaoutar Benabderazak, Muthanna H. Al-Dahhan Nov 2025

Enhanced The Simultaneous Recovery/Extraction Of Combined Heavy Metals Of Lead And Vanadium From Synthetic Wastewater Using An Emulsion Liquid Membrane (Elm) With Nanoparticles And Ionic Liquid, Qusay Al-Obaidi, Nora Yehia Selem, Oumaima Karai, Kaoutar Benabderazak, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recovery/extracting of a combination of lead (Pb(II)) and vanadium (V(V)) ions from wastewater has been enhanced by an emulsion liquid membrane with the presence of magnesium oxide (MgO) or aluminum oxide (Al2O3) nanoparticles (20–50 nm size range) in the internal/stripping phase (W1) and ionic liquid ([OMIM] PF6) in the organic/oil phase (O). The study found that the recovery/extraction batch time was shortened, enhancing emulsion extraction efficiency and stability. Furthermore, the study outcomes extend the ELM separation techniques to industrial-scale pollutant recovery/extraction applications, especially heavy metal ions, from industrial effluent. The percentage of Pb(II) recovery/extraction was increased …


Ded Printing Process Modeling Using Metal Matrix Composites: In-Situ Feedstock Mixing With Variable Compositions And Empirical Validation, Muhammad Arif Mahmood, Sabin Mihai, Diana Chioibasu, Andrei C. Popescu, Frank Liou Nov 2025

Ded Printing Process Modeling Using Metal Matrix Composites: In-Situ Feedstock Mixing With Variable Compositions And Empirical Validation, Muhammad Arif Mahmood, Sabin Mihai, Diana Chioibasu, Andrei C. Popescu, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Directed Energy Deposition (DED) is a promising technology for producing metal matrix composites (MMXCs), but precise control over deposited layer dimensions, particularly in multi-material systems, remains difficult to achieve due to the complex interdependence of operating parameters such as laser parameters, feedstock flow rate, and beam energy attenuation. To address these problems, this work proposes an analytical model that predicts the width, height, and depth of the deposited layers using mixed feedstock compositions in-situ, with a focus on Inconel-718 and TiC MMXCs. The model takes into account variables such as laser power, feedstock density, and mixing ratios to improve layer …


Bending Fatigue In Additively Manufactured Metals: A Review Of Current Research And Future Directions, Md Bahar Uddin, Sriram Praneeth Isanaka, Frank Liou Nov 2025

Bending Fatigue In Additively Manufactured Metals: A Review Of Current Research And Future Directions, Md Bahar Uddin, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metal additive manufacturing (MAM), also referred to as 3D printing, has proven remarkable in the fabrication of complex metal components in multiple sectors. However, the assessment of this revolutionary process through bending fatigue is frequently impeded due to concerns about mechanical and physical conditions of the printed components. The unique layer-by-layer production process results in varied microstructures, anisotropy, and intrinsic defects that considerably differ from traditionally manufactured wrought metals. This review article aims to integrate and evaluate historical and contemporary research on the bending fatigue of additively manufactured materials. More specifically, the impact of process parameters, build orientation, surface conditions, …


Powder Bed Fusion Of Stainless Steel 304l-Nbc Nanocomposite Produced By Ball Milling Method Using A Laser Beam, Khalid Hussain Solangi, Junaid Iqbal Bhatti, Irfan Ali Tunio, Imdad Ali Memon, Temoor Abbas Larik, Lianyi Chen Nov 2025

Powder Bed Fusion Of Stainless Steel 304l-Nbc Nanocomposite Produced By Ball Milling Method Using A Laser Beam, Khalid Hussain Solangi, Junaid Iqbal Bhatti, Irfan Ali Tunio, Imdad Ali Memon, Temoor Abbas Larik, Lianyi Chen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Metal powders with uniformly dispersed nanoparticles, suitable shape, and size for additive manufacturing (AM) processes are highly demanded. However, it is difficult to manufacture metal matrix nanocomposite powders (MMNCs) with uniform dispersion of nanoparticles, optimized shape, and size. This study used high-energy ball milling to disperse NbC nanoparticles with an average length of 400 nm (ex-situ reinforcement) in a Stainless Steel (SS) 304 L matrix. In detail, SS304L-5wt% NbC powders were ball-milled from 4 to 10 h. The results showed that the milled powder particles experienced significant cold-welding during the milling time of 4–6 h, with a wide size distribution. …


Comparative Fire Hazards Of Lithium-Ion Battery Chemistries: Linking Thermal Behavior, Gas Toxicity, And State-Of-Charge To Composite Risk Profiles, Aamir Iqbal, Ashish Kakoria, Syed Talha Riaz, Jingmin Xu, Robert Illango Pushparaj, Guang Xu Nov 2025

Comparative Fire Hazards Of Lithium-Ion Battery Chemistries: Linking Thermal Behavior, Gas Toxicity, And State-Of-Charge To Composite Risk Profiles, Aamir Iqbal, Ashish Kakoria, Syed Talha Riaz, Jingmin Xu, Robert Illango Pushparaj, Guang Xu

Mining Engineering Faculty Research & Creative Works

Lithium-ion batteries (LIB) are widely used in electric vehicles (EVs) for their high energy density. However, their fire safety causes concerns because of the toxic gases emission and the challenge to extinguish. The type and quantity of toxic gases released during battery fires remain among the least studied hazards, with limited data available despite their serious health risks. This study examines the thermal and gaseous emission behavior of LIB cells after thermal runaway (TR). Five cell types, Lithium Iron Phosphate (LFP), Lithium Titanate (LTO), and three Lithium Nickel Manganese Cobalt oxide (NMC). The three NMC variants share the same base …


Atomistic Insights Into Dual Mechanisms For Nacl-Driven Dissolution And Polymerization Of Tricalcium Silicate, Wei Zhang, Jia Sun, Juntao Dang, Bo Tao Huang, Biqin Dong, Hongyan Ma, Dongshuai Hou Oct 2025

Atomistic Insights Into Dual Mechanisms For Nacl-Driven Dissolution And Polymerization Of Tricalcium Silicate, Wei Zhang, Jia Sun, Juntao Dang, Bo Tao Huang, Biqin Dong, Hongyan Ma, Dongshuai Hou

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, experimental characterization and reactive molecular dynamics simulations were integrated to reveal the effects of NaCl on the early hydration of tricalcium silicate (C3S). The results demonstrate that NaCl significantly accelerates the early hydration of C3S by promoting Ca dissolution and silicate tetrahedra polymerization. Specifically, Clions coordinate with surface Ca, weakening the Ca–O bonds in C3S and reducing the energy barrier for Ca dissolution. Meanwhile, Na+ions compete with Ca2+for the O atoms, creating localized charge imbalance and attracting protons, which destabilize Si–O bonds and facilitate the polymerization of silicate tetrahedra. These effects …


Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat Oct 2025

Co2-Induced Changes In Rheology, Structural Evolution, And Particle Characteristics Of Cement Paste, Seongho Han, Tae Yong Shin, Seung Mo Kim, Jae Hong Kim, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The injection of carbon dioxide (CO2) into cementitious systems has emerged as a promising approach to enhancing sustainability in concrete production. This study explores the impact of CO2 injection on the rheological behavior, structural build-up, and particle size evolution of cement paste by systematically varying the water-to-cement ratio (w/c) (0.35, 0.4, and 0.5) and CO2 concentration (0.06, 0.28, and 0.84 mol). Rheological analysis revealed a significant increase in initial yield stress with CO2 injection. Using the Modified Bingham model, yield stress increased by 72 % and 150 % for 0.28- and 0.84-mol CO2, …


Evaluation Of Towed Tem Potential For Rapid Characterization Of Levee Foundations, Kolawole Arowoogun, Katherine Grote, Jeremy Maurer Oct 2025

Evaluation Of Towed Tem Potential For Rapid Characterization Of Levee Foundations, Kolawole Arowoogun, Katherine Grote, Jeremy Maurer

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Assessing the geologic conditions of levee foundation soils is a challenging task owing to the extensive length of most levees and the heterogeneity of many alluvial deposits. Traditional investigation techniques (such as boring and cone penetrometer testing [CPT]) are expensive, invasive, and provide spatially-limited information. As a result, they are restricted to pre-identified problematic zones in the levee. To overcome these challenges, geophysical instruments capable of better spatial coverage are proposed for rapid geoelectrical characterization of levees. In this study, we presented a field-based application of the towed time-domain electromagnetic method (tTEM) system in characterizing the subsurface geology adjacent to …


Tensile And Fatigue Properties Of Haynes ® 233 Manufactured By Wire-Arc Additive Manufacturing, Samuel Onimpa Alfred, Frank W. Liou, Mehdi Amiri Oct 2025

Tensile And Fatigue Properties Of Haynes ® 233 Manufactured By Wire-Arc Additive Manufacturing, Samuel Onimpa Alfred, Frank W. Liou, Mehdi Amiri

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Haynes® 233 is a newly developed nickel-based superalloy currently in the early stages of commercial adoption. With the growing interest in fabricating large and complex components using wire-arc additive manufacturing (WAAM), this alloy presents a promising option for industrial applications. This study investigates the microstructure, tensile, and fatigue properties of heat-treated (HT) WAAM Haynes ® 233 and compares them to its wrought counterpart. Yield strength (YS), ultimate tensile strength (UTS), and fatigue strength of WAAM Haynes ® 233 are 709.4 MPa, 890.1 MPa, and 253.8 MPa, respectively. These values indicate a 63.8 % increase in YS, a 1.11 % decrease …


Laboratory Investigation Of High-Temperature Preformed Particle Gels For Fluid Control In Granite Cores For Geothermal Applications, K. Caleb Darko, Yanbo Liu, Thomas P. Schuman, Mingzhen Wei, Baojun Bai Oct 2025

Laboratory Investigation Of High-Temperature Preformed Particle Gels For Fluid Control In Granite Cores For Geothermal Applications, K. Caleb Darko, Yanbo Liu, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

To understand the applicability of high-temperature preformed particle gel (HT-PPG) for control of short-circuiting in enhanced geothermal systems (EGSs), core flooding experiments were conducted on fractured granite cores under varying fracture widths, gel particle sizes and swelling ratios. Key parameters such as injection pressure, water breakthrough pressure, and residual resistance factor were measured to evaluate HT-PPG performance. The gel exhibited strong injectability, entering granite fractures at pressure gradients as low as 0.656 MPa/m; HT-PPG yields a superior sealing performance by significantly reducing the permeability; and dehydration occurs during HT-PPG propagation, with a dehydration ratio ranging from 4.71% to 11.36%. This …


Stochastic Modeling Of Electromagnetic Wave Propagation Through Extreme Dust Conditions In Underground Mines Using Vector Parabolic Approach, Emmanuel Atta Antwi, Samuel Frimpong, Muhammad Azeem Raza, Sanjay Madria Oct 2025

Stochastic Modeling Of Electromagnetic Wave Propagation Through Extreme Dust Conditions In Underground Mines Using Vector Parabolic Approach, Emmanuel Atta Antwi, Samuel Frimpong, Muhammad Azeem Raza, Sanjay Madria

Mining Engineering Faculty Research & Creative Works

Post-disaster underground (UG) mine environments are characterized by complex and rapidly changing conditions, adding extra attenuation to propagating electromagnetic (EM) waves. One such complex condition is the extreme generation of dust and sudden rise in humidity contributing to extra attenuation effects to propagating waves, especially under varying airborne humidity and dust levels. The existing wave propagation prediction models, especially those that factor in the effect of dust particles, are deterministic in nature, limiting their ability to account for uncertainties, especially during emergency conditions. In this work, the vector parabolic equation (VPE) model is modified to include dust attenuation effects. Using …


Chemistry Of Inclusions By Size In Three Primary Copper Anodes, Charles Campbell, Michael Moats Oct 2025

Chemistry Of Inclusions By Size In Three Primary Copper Anodes, Charles Campbell, Michael Moats

Materials Science and Engineering Faculty Research & Creative Works

Three copper anodes from different commercial electro refineries were characterized to measure inclusion chemistry, size (diameter), and morphology. An automated scanning electron microscope (SEM) paired with energy-dispersive X-ray spectroscopy (EDS) was used to examine hundreds of inclusions near the mold and set sides of each anode. The investigation revealed that in the two anodes with less impurities (99.65% Cu and 99.75% Cu), many of the inclusions were Cu2O with an average diameter of 2 microns. The greater impurity anode (99.05% Cu, 4076 ppm Pb, 1939 ppm As, 635 ppm Bi) contained significant numbers of complex oxide inclusions, averaging 4.6 microns …


Melting Behavior Of Direct Reduced Iron Pellets With Different Carbon Content In Molten Steel And Molten Slag, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley Oct 2025

Melting Behavior Of Direct Reduced Iron Pellets With Different Carbon Content In Molten Steel And Molten Slag, Fabian Andres Calderon Hurtado, Joseph Govro, Arezoo Emdadi, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

This study investigates the melting behavior of direct reduced iron (DRI) pellets in molten slag and steel baths, focusing on how the carbon content influences the melting rate through the stirring effects of gas evolution on heat transfer. A computational model using COMSOL Multiphysics 6.1 is developed to simulate the temperature profile at the pellet's core and the gas evolution resulting from the reaction between FeO and carbon within the pellet. The model is validated using experimental data from this study as well as literature on the DRI pellet–molten slag system. Results indicate that, despite the increased enthalpy demand associated …


Selective Nickel Leaching And Preparation Of Battery-Grade Nickel Carbonate From Copper-Rich Industrial Intermediate, Janaka Jayamini Wijenayake, Michael S. Moats, Lloyd Masuzyo Mseteka, Lana Alagha Oct 2025

Selective Nickel Leaching And Preparation Of Battery-Grade Nickel Carbonate From Copper-Rich Industrial Intermediate, Janaka Jayamini Wijenayake, Michael S. Moats, Lloyd Masuzyo Mseteka, Lana Alagha

Materials Science and Engineering Faculty Research & Creative Works

The rising demand for electric vehicles (EVs) has driven a significant increase in nickel consumption, a critical element in EV battery production. An industrially viable hydrometallurgical process was developed for the selective recovery of nickel from a copper-rich industrial intermediate, containing approximately 70 wt.% Cu and 6 wt.% Ni, predominantly as sulfides alongside minor impurities. Approximately 90% of nickel was selectively extracted via single-stage atmospheric pressure leaching using HCl and H2O2 at 95 °C for 12 h, with the majority of copper retained in the leach residue, which can be utilized as a valuable feedstock for copper smelters. The selectivity …


Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou Oct 2025

Tensile Performance Sensitivity To Variations Of Standard 17-4 Ph Heat Treatments On Lpbf-Produced Material, Ben Brown, Cory Read, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

Standard heat treatments for metals of a particular composition are typically designed with the assumption of a conventional starting microstructure, such as that produced by casting or wrought processing. When applied to metals fabricated by Laser Powder Bed Fusion (LPBF) metal additive manufacturing (AM), these heat treatments can produce inconsistent performance due to the unique as-built microstructures. This study investigates how modifications to standard heat treatments for 17-4 PH steel influence the microstructure and mechanical properties of LPBF-fabricated material. Specimens were produced and subjected to varying solutionizing and homogenizing treatments followed by standard aging treatments. Microstructures were characterized using optical …