Digital Commons Network^™

Local Chemical Ordering Of A Neutron-Irradiated Crfemnni Compositionally Complex Alloy, Nathan Curtis, Sohail Shah, Mukesh Bachhav, Kaustubh Bawane, Fei Teng, Calvin Parkin, Tiankai Yao, Haiming Wen, Adrien Couet

Materials Science and Engineering Faculty Research & Creative Works

While ion-irradiation studies are a critical first step in studying compositionally complex alloys (CCAs) for nuclear applications, they do not capture all the microstructural changes occurring under the low irradiation dose rates and different particles' scattering patterns experienced in a nuclear reactor setting. To explore these phenomena in reactor-relevant conditions for the first time in CCA, the single-phase solid-solution Cr10Fe30Mn30Ni30 was neutron irradiated up to 6.61 displacements per atom at 395 and 579 °C. Irradiation-enhanced local chemical ordering (LCO) well beyond the range of short range ordering was observed, and is predicted to be the precursor to the precipitation of …

The Effect Of Mold Flux Wetting Conditions With Varying Crucible Materials On Crystallization, Muhammad Anwarul Nazim, Arezoo Emdadi, Todd Sander, Ronald O'Malley

Materials Science and Engineering Faculty Research & Creative Works

Understanding mold flux crystallization is essential for assessing heat transfer during steel casting. The complexity of the mold gap presents challenges in identifying the optimal testing method and nucleation type. This study investigates how variations in wetting properties influence nucleation dynamics, in particular the wetting behaviors of mold flux in platinum and graphite crucibles and how they affect crystallization temperatures and solidification mechanisms. Advanced analytical techniques, including confocal laser scanning microscopy (CLSM), and differential scanning calorimetry (DSC) were employed to analyze nucleation under different conditions, with calibration using synthetic slag, Li2SO4, and thermodynamic equilibrium simulations. The findings highlight the crucial …

Deep Learning-Based Gain Estimation For Multi-User Software-Defined Radios In Aircraft Communications, Viraj K. Gajjar, Kurt L. Kosbar

Electrical and Computer Engineering Faculty Research & Creative Works

It may be helpful to integrate multiple aircraft communication and navigation functions into a single software-defined radio (SDR) platform. To transmit these multiple signals, the SDR would first sum the baseband version of the signals. This outgoing composite signal would be passed through a digital-to-analog converter (DAC) before being up-converted and passed through a radio frequency (RF) amplifier. To prevent non-linear distortion in the RF amplifier, it is important to know the peak voltage of the composite. While this is reasonably straightforward when a single modulation is used, it is more challenging when working with composite signals. This paper describes …

Structure-Property Relations Of Binary Ferrite Melts, C. J. Benmore, C. Shi, O. L.G. Alderman, J. P. Harvey, D. Lipke, J. K.R. Weber

Materials Science and Engineering Faculty Research & Creative Works

Molten ferrite systems are used in the smelting and refining processes in steelmaking, to reduce the loss of metals in slags and to accelerate reaction rates. Here, high-energy x-ray diffraction experiments have been performed on aerodynamically levitated molten spheres of 43BaO-57FeOX and 43SrO-57FeOX at 1873 K using laser beam heating. The composition was varied within the range of x = 1-1.5 by changing the oxygen partial pressure of the levitation gas. The corresponding x-ray pair distribution functions have been interpreted using empirical potential structure refinement (EPSR) modeling. In oxygen-rich melts (x = 1.5), our EPSR models indicate very similar structures …

Power System Operations Modeling And Optimization Using Pyomo, Ahmad Heidari, Rui Bo

Graduate Student Research & Creative Works

"The energy sector has witnessed transformative advancements over the past few decades. Power systems, which form the backbone of modern society, have grown increasingly complex with the integration of renewable energy sources, energy storage, and emerging technologies. As these systems evolve, so does the need for efficient operation and optimization strategies to ensure reliability, sustainability, and economic performance.

Optimization plays a central role in solving real-world challenges such as balancing power generation and demand, minimizing operational costs, and managing grid constraints. However, many existing resources tend to focus either on theoretical aspects of optimization or rely on expensive, proprietary software …

A Comprehensive Survey Of Data-Driven Solutions For Lorawan: Challenges And Future Directions, Poonam Maurya, Abhishek Hazra, Preti Kumari, Troels Bundgaard Sørensen, Sajal K. Das

Computer Science Faculty Research & Creative Works

Long-range Wide-area Network (LoRaWAN) is an innovative and prominent communication protocol in the domain of Low-power Wide-area Networks (LPWAN), known for its ability to provide long-range communication with low energy consumption. However, the practical implementation of the LoRaWAN protocol, operating at the Medium Access Control layer and specially built to work upon the LoRa physical layer, presents numerous research challenges, including network congestion, interference, optimal resource allocation, collisions, scalability, and security. To mitigate these challenges effectively, the adoption of cutting-edge data-driven technologies such as Deep Learning (DL) and Machine Learning (ML) emerges as a promising approach. Interestingly, very few existing …

Terminator: A Software Package For Fast And Local Optimization Of His-Tag Placement For Protein Affinity Purification, Rokas Gerulskis, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Although the use of affinity tags can greatly improve purification of expressed enzymes, the placement of affinity tags can significantly impact the expression, solubility, and function of recombinant proteins. To facilitate the optimal design of 6xHis-tagged constructs for protein purification, we developed Terminator, a Python-based software package, which takes a UniProt ID or existing protein sequence as input, identifies related sequences, maps sequence conservation retrieved from ConSurf onto protein 3D structures retrieved from the PDB and SWISS-MODEL, and analyzes proximity to cavities and functional sites to recommend the N- or C-terminus for placement of 6xHis fusion tags 86-100% accuracy in …

Few-Shot Transfer Learning For Individualized Braking Intent Detection On Neuromorphic Hardware, Nathan A. Lutes, V. Sriram Siddhardth Nedendla, K. Krishnamurthy

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work explores use of a few-shot transfer learning method to train and implement a convolutional spiking neural network (CSNN) on a Brain Chip Akida AKD1000 neuromorphic system-on-chip for developing individual-level, instead of traditionally used group-level, models using electroencephalographic data. The efficacy of the method is studied on an advanced driver assist system related task of predicting braking intention. Approach. Data are collected from participants operating an NVIDIA JetBot on a testbed simulating urban streets for three different scenarios. Participants receive a braking indicator in the form of: (1) an audio countdown in a nominal baseline, stress-free environment; (2) an …

Absence Of Tev Halos Around Millisecond Pulsars, A. U. Abeysekara, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, D. Depaoli, P. Desiati, N. Di Lalla, R. Diaz Hernandez, M. A. Duvernois, J. C. Diaz-Velez, K. Engel, T. Ergin, K. L. Fan, K. Fang, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez-Cadena, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, S. Kaufmann, D. Kieda, A. Lara, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, M. Mostafa, M. Najafi, L. Nellen, M. Newbold, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, M. A. Roth, H. Salazar, A. Sandoval, J. Serna-Franco, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, L. Villasenor, Xiaojie Wang, Z. Wang, I. J. Watson, H. Wu, S. Yu

Physics Faculty Research & Creative Works

TeV halos are extended very-high-energy (VHE; 0.1-100 TeV) gamma-ray emission around middle-aged pulsars. So far, they have only been found around isolated pulsars, but it has been suggested that they may also be powered by millisecond pulsars (MSPs). We searched for VHE gamma-ray emission from MSPs reported by radio and GeV gamma-ray observatories in 2565 days of data from the High-Altitude Water Cherenkov (HAWC) Observatory. We found no significant emission from individual pulsars. By combining the likelihood profiles of all MSPs accessible to HAWC, our analysis suggests that the excess emission around the MSP population is consistent with a background. …

Viscoelastic Protective Armor Liners And Protective Armor, Fatih Dogan, Cody Thomas, Catherine Johnson

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Stochastic Generalization Models Learn To Comprehensively Detect Volatile Organic Compounds Associated With Foodborne Pathogens Via Raman Spectroscopy, Bohong Zhang, Anand K. Nambisan, Abhishek Prakash Hungund, Xavier Jones, Qingbo Yang, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

Ensuring food safety requires continuous innovation, especially in the detection of foodborne pathogens and chemical contaminants. In this study, we present a system that combines Raman spectroscopy with machine learning (ML) algorithms for the precise detection and analysis of VOCs linked to foodborne pathogens in complex liquid mixtures. A remote fiber-optic Raman probe was developed to collect spectral data from 42 distinct VOC mixtures, representing contamination scenarios with dilution levels ranging from undiluted to highly diluted states. A dataset comprising 1445 Raman spectra was analyzed using classification and regression ML models, including multi-layer perceptron (MLP), random forest, and extreme gradient …

Study Of Long-Term Spectral Evolution And X-Ray And Γ-Ray Correlation Of Blazars Seen By Hawc, R. Alfaro, C. Alvarez, A. Andrés, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A.Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, F. Carreón, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. Duvernois, M. Durocher, J. C. Diaz-Velez, K. Engel, C. Espinoza, K. L. Fan, N. Fraija, S. Fraija, J. A. Garcia-Gonzalez, F. Garfias, A. Gonzalez Munoz, M. M. Gonzalez, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernandez-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, V. Joshi, S. Kaufman, D. Kieda, A. Lara, W. H. Lee, J. Lee, H. Leon Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, I. Martinez-Castellanos, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, E. Moreno, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, M. Osorio, Y. Perez Araujo, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, M. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, E. Varela, L. Villasenor, Xiaojie Wang, I. J. Watson, K. Whitaker, E. Willox, S. Yun-Carcamo, H. Zhou

Physics Faculty Research & Creative Works

The HAWC Observatory collected 6 yr of extensive data, providing an ideal platform for long-term monitoring of blazars in the very high energy (VHE) band, without bias toward specific flux states. HAWC continuously monitors blazar activity at TeV energies, focusing on sources with a redshift of z ≤ 0.3, based on the Third Fermi-LAT Catalog of High-Energy sources. We specifically focused our analysis on Mrk 421 and Mrk 501, as they are the brightest blazars observed by the HAWC Observatory. With a data set of 2143 days, this work significantly extends the monitoring previously published, which was based on 511 …

Electro-Oxidative Deoxyfluorination Of Arenes With Net3·3hf, En Chih Liu, Sabrina M. Reich, Mayank Tanwar, Matthew Neurock, Long Luo, Melanie S. Sanford

Chemistry Faculty Research & Creative Works

This report describes the design, development, and optimization of an electrochemical deoxyfluorination of arenes using a tetrafluoropyridine-derived leaving group. NEt₃·3HF serves as the fluoride source, and the reactions are conducted using either constant potential or constant current electrolysis in an undivided electrochemical cell. Mechanistic studies support a net oxidative pathway, in which initial single-electron oxidation generates a radical cation intermediate that is trapped by fluoride. The resulting radical undergoes a second oxidation reaction, followed by the loss of the leaving group to yield the fluoroarene product.

Fourier Series For Singular Measures In Higher Dimensions, Chad Berner, John E. Herr, Palle E.T. Jorgensen, Eric S. Weber

Mathematics and Statistics Faculty Research & Creative Works

For multi-variable finite measure spaces, we present in this paper a new framework for non-orthogonal L2 Fourier expansions. Our results hold for probability measures μ with finite support in Rd that satisfy a certain disintegration condition that we refer to as "slice-singular". In this general framework, we present explicit L2(μ)-Fourier expansions, with Fourier exponentials having positive Fourier frequencies in each of the d coordinates. Our Fourier representations apply to every f∈L2(μ), are based on an extended Kaczmarz algorithm, and use a new recursive μ Rokhlin disintegration representation. In detail, our Fourier series expansion for f is in terms of the …

Unconditionally Optimal Convergent Zero-Energy-Contribution Scheme For Two Phase Mhd Model, Jinjin Yang, Shipeng Mao, Xiaoming He

Mathematics and Statistics Faculty Research & Creative Works

This paper focuses on the unconditionally optimal error estimates of a fully discrete decoupled scheme for two-phase magnetohydrodynamic (MHD) model with different viscosities and electric conductivities, by using the zero-energy-contribution (ZEC) method for the temporal discretization and mixed finite elements for the spatial discretization. Based on the ZEC property of the nonlinear and coupled terms of the model, an ordinary differential equation is designed to introduce a nonlocal scalar auxiliary variable which will play a key role in the design and the energy stability of the decoupled scheme. Combining fully explicit treatment on the nonlinear and coupled terms with the …

Simulation-Based Models For Postearthquake Response: A Survey And Research Directions, Abhijit Gosavi, Lauryn A. Spearing, Lesley H. Sneed

Engineering Management and Systems Engineering Faculty Research & Creative Works

Computer simulation is increasingly being used by emergency planners as a tool to improve disaster response given that it can model real-world scenarios, such as earthquakes. Although there has been an increase in simulation research focused on disaster response, much of this literature is from disparate fields and across disaster scenarios. To bridge this gap, this paper surveys simulation-based models for post-earthquake response from the year 2000 onward. Advantages of simulation over closed-form statistical models are discussed. Three main subproblems in post-earthquake response models are explored: (1) service distribution (e.g., food, water), (2) infrastructure restoration (at the building and transportation …

Blast Tube Design: How Shape And Size Influence The Resultant Shock Wave, R. L. Bauer, C. E. Johnson

Mining Engineering Faculty Research & Creative Works

Shock tubes and tunnels are often used in research settings as a way of producing high pressure shock waves in a smaller footprint or without the use of explosives. However, there is no standard geometric design across laboratories. Peak pressure is a significant parameter for characterizing a shock wave. However, different tube configurations could also affect parameters such as impulse and duration, yet no research has investigated how the scale of the tube affects the overall waveform shape. To understand the implications of shock tube design, tubes with a constant length to diameter ratio were evaluated to determine how tube …

February 2025 Cafe Newsletter, Center For Advancing Faculty Excellence

CAFE Faculty Newsletters

No abstract provided.

Reflections On The Origin Of Linear B, (Part 8); Sign 16 (Looks Like A Human Head) And Its Possible Connection To The Ancient Egyptian God Ptaḥ, Gerald Leonard Cohen

Arts, Languages and Philosophy Faculty Research & Creative Works

This article suggests a rationale for the shape of Linear B sign 16 being that of a human head: The sign likely derives from the ancient Egyptian hieroglyph for ‘face’ (recognized already by Sundwall and Evans) and very possibly honors the ancient Egyptian god Ptah, described as ‘Beautiful of Face.’ Also, remarkably, a total of three Linear B signs may be traceable directly to Ptah, and a fourth one (shared with Osiris) may be connected with him too.

Multi-Scale Modeling Of Transport Properties In Cementitious Materials With Go Admixture, Bing Liu, Weichen Kang, Weixing Lian, Feng Xing, Hongfang Sun, Hongyan Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In coastal areas, the presence of concrete cracks provides pathways for hazardous ions to ingress from the exterior into the interior of concrete, while the migration of the ions further accelerates concrete deterioration and causes durability problems. The incorporation of graphene oxide (GO) into concrete can inhibit crack initiation and development starting at the nanoscale, improving the concrete microstructure, thereby affecting concrete's resistance to hazardous ion transport and the resulting deterioration. In this study, a multi-scale transport model for cementitious materials with a GO admixture was established to predict the resistance to hazardous ions. Based on the determination of hydration …

Application Of Convolutional Neural Network For Seismic Event Classification: Impact Of Dataset Quality, Distribution, And Human-In-The-Loop Feedback, Yanwei Zhang, Stephen S. Gao, Xiaoyi Fan, Shaohui Zhou, Junhao Qu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Convolutional neural networks (CNNs) have gained popularity in geophysical research due to their exceptional performance in various areas. However, achieving reliable results with CNNs typically requires a significant amount of high-quality data for training. In this study, we develop a CNN to classify natural earthquakes, mine collapses, and explosions using seismic waveforms from 287 stations in Shandong Province, China. The dataset comprises 1035 earthquakes, 159 mine collapses, and 586 explosions. To address the impact of unreliable measurements, we employ cross validation to screen, manually correct, or discard measurements with inconsistent labels assigned by human experts and CNN. By refining the …

A Comprehensive Study Of Cooling Rate Effects On Diffusion, Microstructural Evolution, And Characterization Of Aluminum Alloys, Atiqur Rahman, Sriram Praneeth Isanaka, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Cooling Rate (CR) definitively influences the microstructure of metallic parts manufactured through various processes. Factors including cooling medium, surface area, thermal conductivity, and temperature control can influence both predicted and unforeseen impacts that then influence the results of mechanical properties. This comprehensive study explores the impact of CRs in diffusion, microstructural development, and the characterization of aluminum alloys and the influence of various manufacturing processes and post-process treatments, and it studies analytical models that can predict their effects. It examines a broad range of CRs encountered in diverse manufacturing methods, such as laser powder bed fusion (LPBF), directed energy deposition …

Controlling Structural Phases Of Sn Through Lattice Engineering, Chandima Kasun Edirisinghe, Anjali Rathore, Taegeon Lee, Daekwon Lee, An Hsi Chen, Garrett Baucom, Eitan Hershkovitz, Anuradha Wijesinghe, Pradip Adhikari, Sinchul Yeom, Hong Seok Lee, Hyung Kook Choi, Hyunsoo Kim, Mina Yoon

Physics Faculty Research & Creative Works

Topology and superconductivity, two distinct phenomena, offer unique insight into quantum properties and their applications in quantum technologies, spintronics, and sustainable energy technologies. Tin (Sn) plays a pivotal role here as an element because of its two structural phases, α-Sn exhibiting topological characteristics and β-Sn showing superconductivity. Here, we demonstrate precise control of these phases in Sn thin films using molecular beam epitaxy with systematically varied lattice parameters of the buffer layer. The Sn films exhibit either β-Sn or α-Sn phases as the buffer layer's lattice constant varies from 6.10Å to 6.48Å, spanning the range from GaSb (like InAs) to …

Rheology And Early-Age Structure Development In Binary And Ternary Blends Modified With Novel Graphene Types, Sahil Surehali, Collin Gustafson, Sayee Srikarah Volaity, Ranjith Divigalpitiya, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Interest in the use of graphene to enhance the properties of cementitious materials is growing, but major impediments in implementation are the cost of graphene and changes in binder rheology attributable to these nanomaterials. This study explores the influence of novel, cost-effective, environment-friendly, and mass-producible graphene on the rheology and early-age structure development of cementitious binders. Two novel graphene types—fractal graphene (FG) and reactive graphene (RG)—are used in plain cement mixtures as well as those containing 30 % (by mass) of fly ash and/or limestone powder, at low dosages of ≤0.02 % by mass of binder. The early- and later-age …

Uav-Based Phytoforensics: Hyperspectral Image Analysis To Remotely Detect Explosives Using Maize (Zea Mays), Paul V. Manley, Stephen M. Via, Joel G. Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Remnant explosive devices are a deadly nuisance to both military personnel and civilians. Traditional mine detection and clearing is dangerous, time-consuming, and expensive. And routine production and testing of explosives can create groundwater contamination issues. Remote detection methods could be rapidly deployed in vegetated areas containing explosives as they are known to cause stress in vegetation that is detectable with hyperspectral sensors. Hyperspectral imagery was employed in a mesocosm study comparing stress from a natural source (drought) to that of plants exposed to two different concentrations of Royal Demolition Explosive (RDX; 250 mg kg−1, 500 mg kg−1). Classification was accomplished …

Effect Of Shrinkage-Mitigating Materials, Fiber Type, And Repair Thickness On Flexural Behavior Of Beams Repaired With Fiber-Reinforced Self-Consolidating Concrete, Jingjie Wei, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

While self-consolidating concrete (SCC) has emerged as a highly effective approach for the repair of concrete structures, there have been few investigations regarding the effect of the combination of different fiber and shrinkage-mitigating material types (shrinkage-reducing admixture, SRA; superabsorbent polymer, SAP; and expansive agent, EA) on the flexural behavior of repaired structures. This study aims to explore the influence of three different shrinkage-mitigating materials (1.25%–2.5 % SRA, 4%–8% EA, and 0.2%–0.4 % SAP), four fiber types (two macro synthetic fibers, MSFA and MSFB; 5D hooked steel fibers, 5D; a combination of 80 % 3D hooked steel +20 % short steel …

Helicity Modulus And Chiral Symmetry Breaking For Boundary Conditions With Finite Twist, Gaurav Khairnar, Thomas Vojta

Physics Faculty Research & Creative Works

We study the response of a two-dimensional classical XY model to a finite (noninfinitesimal) twist of the boundary conditions. We use Monte Carlo simulations to evaluate the free energy difference between periodic and twisted-periodic boundary conditions and find deviations from the expected quadratic dependence on the twist angle. Consequently, the helicity modulus (spin stiffness) shows a nontrivial dependence on the twist angle. We show that the deviation from the expected behavior arises because of the mixing of states with opposite chirality which leads to an additional entropy contribution in the quasi-long-range ordered phase. We give an improved prescription for the …

Assessing The Impact Of Radar-Rainfall Uncertainty On Streamflow Simulation, Nicolás Velásquez, Witold F. Krajewski, Bong Chul Seo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hydrological models and quantitative precipitation estimation (QPE) are critical elements of flood forecasting systems. Both are subject to considerable uncertainties. Quantifying their relative contribution to the forecasted streamflow and flood uncertainty has remained challenging. Past work documented in the literature focused on one of these elements separately from the other. With this in mind, we present a systematic approach to assess the impact of QPE uncertainty in streamflow forecasting. Our approach explores the operational Iowa Flood Center (IFC) hydrological model performance after altering two radar-based QPE products. We ran the Hillslope Link Model (HLM) for Iowa between 2015 and 2020, …

Oxidation–Reduction Of Ti-6al-4v In Direct Energy Deposition Subject To Minimum Argon Consumption, Bharadwaja Ragampeta, Prashansa Ragampeta, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ti-6Al-4V is a well-known alloy for its low density and excellent corrosion resistance, making it popular in aerospace, marine, medical, and automotive applications. However, at elevated temperatures, the alloy forms oxides, leading to embrittlement. In additive manufacturing, particularly in the direct energy deposition (DED) process, which involves high temperatures, the alloy experiences oxidation. An inert gas chamber provides shielding during the process but limits the size of the manufactured components, and deposition in a vacuum chamber can alter the chemical composition of the alloy. Local shielding is a technique generally used for such applications, but it uses a high volume …

Thermally Stimulated Stiffening And Fly Ash's Alkaline Activation By Ca(Oh)2 Addition Facilitates 3d-Printing, Xiaodi Dai, Sharu Bhagavathi Kandy, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gaedt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

3D-printing could offer substantial benefits to the construction industry including the fabrication of customized/bespoke components, eliminating formwork, and reducing material waste. Despite these advantages, control of the pumpability, extrudability, and buildability of 3D-printed concrete (3DPC) remains challenging. This study demonstrates how the use of fly ash (FA) enables enhanced thermal stiffening, and rapid alkali-activation in the presence of portlandite (Ca(OH)2, CH). In general, blends of CH and FA exhibit less structural build-up at low temperatures, but upon reaching a trigger temperature of 75 °C, these blends achieve rapid stiffening, at rates of ∼800 Pa/s. The rapid stiffening arises from the …