Engineering Commons^™

Martensitic Transformation Induced Strength-Ductility Synergy In Additively Manufactured Maraging 250 Steel By Thermal History Engineering, Shahryar Mooraj, Shuai Feng, Matthew Luebbe, Matthew Register, Jian Liu, Tianyi Li, Baris Yavas, David P. Schmidt, Matthew W. Priddy, Michael B. Nicholas, Victor K. Champagne, Mark Aindow, Haiming Wen, Wen Chen

Materials Science and Engineering Faculty Research & Creative Works

Maraging steels are known for their exceptional strength but suffer from limited work hardening and ductility. Here, we report an intermittent printing strategy to tailor the microstructure and mechanical properties of maraging 250 steel via tuning the thermal history during wire-arc directed energy deposition. By introducing a dwell time between adjacent layers, the maraging 250 steel is cooled below the martensite start temperature, triggering thermally driven martensitic transformation during the printing process. Thermal cycling during subsequent layer deposition results in the formation of reverted austenite which shows a refined microstructure and induces elemental segregation between martensite and reverted austenite. The …

The Interplay Between Endothelial Glycocalyx Maturity And Both The Toxicity And Intracellular Uptake Of Charged Nanoparticles, Claire A. Bridges, Lu D. Fu, Jonathan A. Yeow, Xiaojing D. Huang, Miriam D. Jackson, Rhiannon P. Kuchel, James D. Sterling, Shenda M. Baker, Megan S. Lord

Business and Information Technology Faculty Research & Creative Works

Nanoparticles are widely studied for delivering treatments to target tissues, but few have reached clinical use. Most nanoparticles encounter blood vessels on their way to target tissues. The inner surface of these vessels is lined with endothelial cells covered by a glycocalyx, an extracellular matrix rich in anionic glycans. The role of the glycocalyx in nanoparticle interactions is not well understood. Here, we demonstrate that endothelial cells need extended culture times to synthesize a mature glycocalyx. Our research shows that branched polyethyleneimine functionalized gold nanoparticles bind to endothelial cells expressing either a developing or mature glycocalyx, with the interaction involving …

Experiment-Based Superposition Thermal Modeling Of Laser Powder Bed Fusion, Cody S. Lough, Tao Liu, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, Ben Brown, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Parts experience significant local thermal variations during the Laser Powder Bed Fusion (LPBF) metal Additive Manufacturing (AM) process, providing a potential source of defects. Near real-time thermal predictions can enable better process planning and facilitate corrections on subsequent layers to enable the engineering of laser parameter and scan path combinations that avoid defect inducing scenarios. This paper considers an experiment-based Discrete Green's Function (DGF) thermal model for temperature field prediction in LPBF. An analytical framework is developed and used to calculate an experimental DGF (i.e., powder bed's single pulse temperature response) from spatiotemporal Short-Wave Infrared (SWIR) camera data. The extracted …

Correlating The Compositional Changes To The Rheological Properties Of Recovered Asphalt Binders From Recycled Asphalt Mixtures: Insights From The Thermogravimetric Measurements, Eslam Deef-Allah, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Assessing the binder performance of thermal characterization is critical for quality control. This is pertinent for recovered binders from mixtures, which may not be in adequate quantities to evaluate their performance, particularly in mixtures containing reclaimed asphalt pavement (RAP). The present study deployed a thermogravimetric analyzer to evaluate compositional changes in recovered binders from RAP-containing mixtures, focusing on thermograph and derivative of thermograph (DTG) characteristics and correlating the results to rheological features. Incorporating RAP in mixtures influenced recovered binders' DTG shapes, reducing low-combusted components (%LCC) and increasing residues (%R). The recovered binder from the zero-RAP-containing mixture showed a 4.36% increase …

How Shearing Affects Air Dissolution In Fresh Cement Pastes Under Pressure, Daniel Galvez-Moreno, Dimitri Feys, Kyle Riding

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The air-void system of concrete is of paramount importance to ensure freeze–thaw durability. Pumping induces detrimental changes in the air-void system of concrete by dissolving the air bubbles in the surrounding water when pressure increases due to the pump action. This research work investigates the influence of shear rate and air-void size distribution on air dissolution with time of cement pastes under pressure. Steady-state shear rheology at different shear rates was applied on samples of different air-void size distributions but similar air contents. Due to the low capillary number of the mixtures, the application of pressure caused a decrease in …

Impact Of Aggregate Characteristics On Frictional Performance Of Asphalt-Based High Friction Surface Treatments, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High Friction Surface Treatments (HFST) are recognized for their effectiveness in enhancing skid resistance and reducing road accidents. While Epoxy-based HFSTs are widely applied, they present limitations such as compatibility issues with existing pavements, high installation and removal costs, and durability concerns tied to substrate quality. As an alternative to traditional Epoxy-based HFSTs, this study investigated the effects of aggregate gradation as designated by agencies on the performance of asphalt-based HFST. Various aggregate types were assessed to evaluate friction performance and the impact of polishing cycles on non-Epoxy HFST. It was found that adjustments in aggregate size and gradation may …

A Low-Carbon Approach For Lime Production Using Self-Propagating High Temperature Synthesis-Driven Limestone Calcination, Shubham Agrawal, Sayee Srikarah Volaity, Srinivas Kilambi, Aditya Kumar, Narayanan Neithalath

Materials Science and Engineering Faculty Research & Creative Works

Limestone calcination produces calcium oxide (or lime), that forms the basis for the manufacturing of many critical engineering materials such as cement and iron-and-steel. Limestone calcination—an endothermic reaction—is regarded as one of the most energy-and-CO₂ intensive industrial chemical reactions, and is facilitated by fossil fuels, since the high temperature requirement (∼900 °C) renders it less conducive to electrification through renewable energy sources. In this study, a novel, low-temperature (∼450 °C) pathway for ultrafast calcination of limestone using combustion synthesis or self-propagating high-temperature synthesis (SHS) is developed. SHS leverages exothermic heat from the combustion of lignin or biomass—as low-carbon fuels—mixed …

Understanding The Underlying Trends In Us Construction Labor Wages: A Data-Driven Mixed-Method Computational Approach, Bahaa Chammout, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Precisely forecasting construction costs is crucial for maintaining financial stability for contractors and the broader construction sector. Nonetheless, this task has long been acknowledged as challenging. Recent global events and inflationary pressures have notably driven up construction labor expenses. While existing research examined labor shortages, there remains a gap in understanding the diverse labor wage trends. This paper addresses this research gap following a multistep methodology, which included: (1) gathering construction labor data from 1999 to 2023; (2) conducting trend and statistical analyses to discern the underlying patterns in labor trends; (3) employing clustering analysis to categorize construction occupations based …

Engineering Pamam Dendrimers For Optimized Drug Delivery, Amin Aleebrahim Dehkordi, Shirin Mollazadeh, Amirreza Talaie, Mostafa Yazdimamaghani

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dendrimers, first introduced by Fritz Vögtle in 1978, have emerged as promising nanocarriers for drug delivery due to their unique branched architecture, large internal cavities, and numerous surface amine groups. These dendrimers efficiently load various drugs through electrostatic interactions, covalent bonding, or encapsulation, owing to their high density of terminal amine groups. However, the inherent cationic nature of PAMAM dendrimers can lead to cytotoxicity and limited systemic circulation due to interactions with negatively charged biomolecules. To address these limitations, surface modification strategies have been developed to enhance targeting, trigger-controlled drug release, and decrease cytotoxicity. This review critically examines recent advancements …

Design And Function Of Thermoresponsive-Ultrafast Stiffening Suspension Formulations For 3d Printing, Sharu Bhagavathi Kandy, Sebastian Remke, Thiyagarajan Ranganathan, Shubham Kiran Wani, Xiaodi Dai, Narayanan Neithalath, Aditya Kumar, Mathieu Bauchy, Edward Garboczi, Torben Gädt, Samanvaya Srivastava, Gaurav Sant

Materials Science and Engineering Faculty Research & Creative Works

An inability to accurately control the rate and extent of solidification of cementitious suspensions is a major impediment to creating geometrically complex structural shapes via 3D printing. In this work, we have developed a thermoresponsive rapid stiffening system that will stiffen suspensions of minerals such as quartz, limestone, portlandite, and Ordinary Portland Cement (OPC) over a wide pH range. When exposed to trigger temperatures between 40 °C and 70 °C, the polymer binder system undergoes a thermally triggered free radical polymerization (FRP) reaction, leading to an ultrafast stiffening of the suspension at an average rate on the order of 1 …

Compositionally Complex Alb2-Type Diborides In Dissociated Air Plasma, F. Monteverde, C. Pellegrini, M. Balat-Pichelin, William Fahrenholtz, Greg Hilmas

Materials Science and Engineering Faculty Research & Creative Works

Multi-metal compositionally complex (CC) AlB2-type diboride solid solutions (SS) containing IV-V-VI group elements are garnering a steadily growing research interest. The present work explores the composition dependence of oxidation resistance on nominally equiatomic (Hf,Me,Ta,Ti,Zr)B2 SS, Me = Nb or Cr, exposed to a dissociated air plasma (total pressure of about 1 kPa): specimens were exposed for 5 min at some selected set points between 1800 K and 2500 K using a solar furnace. The CC diboride with Nb showed superior resistance to oxidation compared to that with Cr. The experimental results showed good agreement with predictions based on a thermodynamic …

Dynamic Tensile Properties Of Thermally Treated Concrete Specimens Subjected To Varied Heating Rates: An Investigation Using The Digital Image Correlation Method, Ronghua Shu, Jiabao Cheng, Guang Xu, Yuzhang Lai, Lijinhong Huang

Mining Engineering Faculty Research & Creative Works

In concrete engineering, high temperatures at varying heating rates significantly affect the stability of concrete structures. In this paper, the dynamic tensile characteristics were investigated on concrete specimens subjected to heating rates ranging from 2 to 40 °C/min, using the digital image correlation (DIC) method. The results reveal a critical heating rate threshold, between 5 and 10 °C/min, which marks a shift in the influence of heating rates on both physical and dynamic tensile properties. Below this threshold, changes are minimal, but beyond it, significant effects are observed. As the heating rate increases, longitudinal wave velocity, density, and mass decrease, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …