Materials Science and Engineering Commons^™

Using Dft On Ultrasound Measurements To Determine Patient-Specific Blood Flow Boundary Conditions For Computational Hemodynamics Of Intracranial Aneurysms, Hang Yi, Zifeng Yang, Luke Bramlage, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

Boundary conditions (BCs) is one pivotal factor influencing the accuracy of hemodynamic predictions on intracranial aneurysms (IAs) using computational fluid dynamics (CFD) modeling. Unfortunately, a standard procedure to secure accurate BCs for hemodynamic modeling does not exist. To bridge such a knowledge gap, two representative patient-specific IA models (Case-I and Case-II) were reconstructed and their blood flow velocity waveforms in the internal carotid artery (ICA) were measured by ultrasonic techniques and modeled by discrete Fourier transform (DFT). Then, numerical investigations were conducted to explore the appropriate number of samples (N) for DFT modeling to secure the accurate BC by comparing …

Predicting Rheology Of Uv-Curable Nanoparticle Ink Components And Compositions For Inkjet Additive Manufacturing, Cameron D. Lutz

Master's Theses

Inkjet additive manufacturing is the next step toward ubiquitous manufacturing by enabling multi-material printing that can exhibit various mechanical, electronic, and thermal properties. These characteristics are realized in the careful formulation of the inks and their functional materials, but there are many constraints that need to be satisfied to allow optimal jetting performance and build quality when used in an inkjet 3-D printer. Previous research has addressed the desirable rheology characteristics to enable stable drop formation and how the metallic nanoparticles affect the viscosity of inks. The contending goals of increasing nanoparticle-loading to improve material deposition rates while trying to …

Scaffold-Free Development Of Multicellular Tumor Spheroids With Spatial Characterization Of Structure And Metabolic Radial Profiles, Shelby N. Bess, Gaven K. Smart, Matthew J. Igoe, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Purpose

In vitro assays are essential for studying cellular biology, but traditional monolayer cultures fail to replicate the complex three-dimensional (3D) interactions of cells in living organisms. 3D culture systems offer a more accurate reflection of the cellular microenvironment. However, 3D cultures require robust and unique methods of characterization.

Methods

The goal of this study was to create a 3D spheroid model using cancer cells and macrophages, and to demonstrate a custom image analysis program to assess structural and metabolic changes across spheroid microregions.

Results

Structural characterization shows that cells at the necrotic core show high normalized fluorescence intensities of …

Photodegradation Of Microplastics Through Nanomaterials: Insights Into Photocatalysts Modification And Detailed Mechanisms, Yiting Xiao, Yang Tian, Wenbo Xu, Jun Zhu

Biological and Agricultural Engineering Faculty Publications and Presentations

Microplastics (MPs) pose a profound environmental challenge, impacting ecosystems and human health through mechanisms such as bioaccumulation and ecosystem contamination. While traditional water treatment methods can partially remove microplastics, their limitations highlight the need for innovative green approaches like photodegradation to ensure more effective and sustainable removal. This review explores the potential of nanomaterial-enhanced photocatalysts in addressing this issue. Utilizing their unique properties like large surface area and tunable bandgap, nanomaterials significantly improve degradation efficiency. Different strategies for photocatalyst modification to improve photocatalytic performance are thoroughly summarized, with a particular emphasis on element doping and heterojunction construction. Furthermore, this review …

Waste Illuminates Worlds: Printed Modular Lamp Design Based On Brick And Clay Tile, Yechen Zhu

Masters Theses

The building industry in the New England area is often in a state of entropy, with abandoned brick buildings contributing to urban decay. The recycling rate of brick and clay tile wastes generated by construction and demolition is only 12.2%, meaning the majority is sent to landfills. The expansion of landfills can lead to significant environmental and community challenges, including increased traffic from waste transport, habitat destruction, ecosystem degradation, and contributions to climate change. Specifically, the Bethlehem landfill in New Hampshire, which is planned to undergo a 5.71-acre lateral expansion through 2026, has already encountered issues such as leachate spills …

Using Micromoments And Concept Maps To Enhance Entrepreneurially Minded Learning Of Indoor Air Pollution Control, Jean M. Andino, Erick Salvador Vasquez-Guardado, Ricardo Gomez Gonzalez, Xiaojing Yuan, Nilza D. Aples

Chemical and Materials Engineering Faculty Publications

Micromoments targeted toward indoor air quality were introduced to students in an Air Quality Engineering course to enhance their entrepreneurial mindset. Three micromoment activities, i.e., “Question Frenzy”, “Make It Relevant”, and “How Do We Make It Better?” that are linked, respectively, to the curiosity, connections, and creating value elements of EM were deployed in the class in the context of the use of a Corsi Rosenthal cube (a do-it-yourself structure that has recently become popular as an inexpensive way to reduce indoor particle pollution). Students generated concept maps pre-and post- micromoment intervention using the freely available CMap Tools software. The …

Polypropylene As Partial Fine Aggregate Substitute In Concrete, Samuel E. Royston, Chrisitan G. Achkar, Nicholas B. Tabarez

Architectural Engineering

The objective of this project is to discover a structurally effective method in repurposing recyclable plastic waste through its partial substitution for traditional fine aggregate in concrete.

Results obtained from analysis indicate a 25 percent compressive strength reduction with polypropylene at a 10 percent partial substitution for total sand content. This material successfully performed as an alternative, presenting a ductile mode of failure.

Three material alternatives - polypropylene, polyethylene, and rubber - were substituted for a percentage of sand. These materials underwent concrete cylinder crushing tests to determine their ultimate crushing strength, with the intent of identifying the most effective …

Design, Modeling, And Testing Of A Novel Inductor For Electric Vehicles: Iron Nitride Soft Magnetic Composites, Cody Krawczyk, Lauren Walker

Materials Engineering

The purpose of this study is to develop a processing method to reduce the porosity of toroidal inductors, whose cores are composed of soft magnetic composites (SMCs) with 65 vol.%, 75 vol.%, and 85 vol.% iron nitride (γ′-Fe₄N) and to validate the results with a COMSOL^TM model. Using hot-pressing as the main process of manufacture, fourteen samples were fabricated and eight were wound with Litz wire. Four samples of 75 vol.% and four samples of 85 vol.% were fabricated by mixing the Fe₄N powder and epoxy at 150^oC and initially pressing at 5 …

Characterization Of High Albedo Ground Surface Treatments For Energy Harvesting By Bifacial Photovoltaic Power Plants, Roma C. Chatripally, Matthew Honda, James Vance

Materials Engineering

Bifacial photovoltaic (bPV) cells have higher solar efficiency than monofacial photovoltaic (mPV) cells due to having two sides of active layers. bPV cells also require less space to produce equivalent electricity, which is useful for solar farms that want to maximize energy output per unit area. Placing a sheet of highly reflective material on the surface beneath bPV cells further increases their efficiency due to increasing the amount of solar radiation that reaches the underside of the bPV cells. This study explores the effects of natural outdoor weathering, solar altitude angle, and accelerated exposure to UV radiation on the albedos …

Metallurgical Impact Of Switching From Hammer Units To Hydraulic Presses For Forging, Cole Hawker, Jacob Reed

Materials Engineering

Carlton Forge Works (CFW) is evaluating the retirement of its hammer units in favor of hydraulic presses to address safety concerns in forging aerospace components. This paper investigates the metallurgical implications of this transition, emphasizing the importance of superior microstructures and meeting industry standards and customer requirements. The alloys in question are Titanium-6Al-4V (Ti64) and Inconel 718 (INCO 718), which comprise a majority of CFW’s production. Ti64's high specific strength and thermal stability make it ideal for aerospace applications, while INCO 718 is recognized for superior high-temperature creep performance. Defects like freckles and white spots in INCO 718 are analyzed …

Printed Graphite Electrodes For Fast-Charging Lithium-Ion Batteries, Guanyi Wang

Dissertations

The rapid growth of the electric vehicle (EV) market has demanded lithium-ion batteries (LIBs) with high energy density and fast charging capability. However, charging energy-dense LIBs with thick graphite electrodes at high current densities is typically facing challenges and leading to adverse performance, such as low energy density, short cycle life, rapid temperature rises and safety issues. The root cause is the onset of Li plating. During fast charging application, the sluggish lithium ions accumulated at the surface of graphite due to kinetic limitation and formed Li plating, especially when lithiated to a high state of charge (SOC). It has …

Non-Linear Modeling Of Hysteresis In Piezoelectric Actuated Cantilever Beam Using The Bouc-Wen Model, Andrew Donald Maas

Master's Theses

Piezoelectric actuators frequently exhibit a time-dependent behavioral phenomenon known as hysteresis, resulting in a lag in the deformation of the actuator compared to linear models. The presence of hysteresis complicates control systems involving piezoelectric actuators. However, traditional modeling methods for piezoelectric actuated smart structures often treat the piezoelectric patches as linear actuators without considering hysteresis, leading to suboptimal controller performance.

This thesis aims to establish a comprehensive model by integrating the Euler-Bernoulli beam bending model with the hysteresis dynamics induced by two opposing piezoelectric patches attached to a beam. A model expansion method is employed to transform the partial differential …

Comparison Of Pm-Hip To Forged Sa508 Pressure Vessel Steel Under High-Dose Neutron Irradiation, Wen Jiang, Yangyang Zhao, Yu Lu, Yaqiao Wu, David Frazer, Donna P. Guillen, David W. Gandy, Janelle P. Wharry

Materials Science and Engineering Faculty Publications and Presentations

Powder metallurgy with hot isostatic pressing (PM-HIP) is an advanced manufacturing process that is envisioned to replace forging for heavy nuclear components, including the reactor pressure vessel (RPV). But PM-HIP products must at least demonstrate comparable irradiation tolerance than forgings in order to be qualified for nuclear applications. The objective of this study is to directly compare PM-HIP to forged SA508 Grade 3 Class 1 low-alloy RPV steel at two neutron irradiation conditions: ∼0.5–1.0 displacements per atom (dpa) at ∼270 °C and ∼370 °C. PM-HIP SA508 experiences greater irradiation hardening and embrittlement (total elongation) than forged SA508. However, uniform elongation …

In Situ And 2d And 3d In Silico Redox Cycling Studies For Design Optimization Of Coplanar Arrays Of Microband Electrodes In A 70 Μm × 100 Μm Electroactive Footprint, Miguel Angel Abrego Tello, Mahsa Lotfi Marchoubeh, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

Optimization of redox-cycling currents was performed by adjusting the height (sidewalls, h), width (w), and length (l) of band electrodes and their spacing (w_gap) in coplanar arrays restricted to a small-electroactive window of 70 × 100 μm. These arrays can function in μL-volumes for chemical analysis (e.g., in-vivo dopamine detection using probes). Experiments were conducted with an array of five electrodes (NE = 5), w = 4.3 μm, w_gap = 3.7 μm, h = 0.150 μm, and l = 99.2 μm. Reasons for …

Modeling Charging Current Dynamics At Microelectrodes And Their Interfaces With Electrolyte And Insulators With A Focus On Microfabricated Gold Microband Electrodes On An Su-8 Substrate, Miguel Angel Abrego Tello, Mahsa Lotfi Marchoubeh, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

The suitability of electrochemical methods for quantitative measurements at microdevices is influenced by the relatively large electrode-insulator interface-to-electrode area ratio, greatly impacting charging dynamics due to interactions among electrolyte, conductor material, and insulator layers. The resulting charging current can overwhelm the faradaic current from redox chemistry. The device studied here features a 70 μm × 100 μm electroactive window, hosts gold coplanar microband electrodes, and is insulated by SU-8, which serves as both overlayer and substrate. The overlayer defines the electroactive length and isolates the leads of the electrodes from the sample solution. Cyclic voltammetry in 0.10 M …

Assessing Global Engagement Interventions To Advance Global Engineering Competence For Engineering Formation, Scott Schneider, Erick S. Vasquez-Guardado, Corinne Mowrey, Michael Moulton, Homero Murzi, Matthew A. Witenstein

Chemical and Materials Engineering Faculty Publications

This paper summarizes the work performed during the first year of a collaborative Research Initiation in Engineering Formation (RIEF) project focused on assessing the formation of a global learner mindset in engineering students through the use of different types of global engagement interventions without extended international travel. During this year the global engagement interventions have been developed, piloted, and assessed using the Global Engagement Survey (GES) and Global Engineering Competency Scale (GECS) instruments in a pre and post format. The assessment results helped the research team update the interventions and refine the assessment strategy, including the addition of new qualitative …

Work In Progress: Exploring The Impact Of International Experiences On The Development Of Students’ Entrepreneurial Mindset, Olgha Bassam Qaqish, Marcia Poole, William Pennock, Erick S. Vasquez-Guardado, Fahmidah Ummul Ashraf

Chemical and Materials Engineering Faculty Publications

International experiences, including collaborative online international learning (COIL) experiences that naturally increase accessibility, are of interest to many undergraduate students. These experiences provide educators a unique opportunity to develop a student's entrepreneurial mindset (EM). Additionally, hands-on experiences aligned with the National Academy of Engineering’s (NAE) grand challenge themes (Sustainability, Security, Health, and Joy of Living) support connections between the experience, disciplinary knowledge, multicultural awareness, and EM. Through this Work-in-Progress (WiP) study, we seek to answer: 1) How do international experiences influence undergraduate science and engineering students’ EM, and 2) How does the international experience modality (i.e., study abroad or COIL) …

Enhancing Entrepreneurial Minded Learning Of Process Control And Heat Transfer Concepts Using Micromoments And Concept Maps, Erick S. Vasquez-Guardado, Ricardo Gomez Gonzalez, Jean M. Andino, Nilza D. Aples, Xiaojing Yuan

Chemical and Materials Engineering Faculty Publications

The Entrepreneurially Minded Learning (EML) Framework seeks to infuse an Entrepreneurial Mindset in engineering students. The EML framework is founded on the 3 C’s principles of curiosity, connections, and creating value. Assessing EML efforts, however, is a well-known challenge for many engineering courses that do not have a design component. Through concept maps and micromoment activities, this work seeks to answer the following questions: Does implementing micromoment activities enhance students’ EML in two core areas of chemical engineering, i.e., heat transfer and process controls? A secondary research question is whether introducing a physical device in lectures enhances students’ EML. The …

Settingsorder Article Reprints Open Accesseditor’S Choicearticle Exploring The Impact Of Spray Process Parameters On Graphite Coatings: Morphology, Thickness, And Tribological Properties, Adedoyin Abe, Josue A. Goss, Min Zou

Mechanical Engineering Faculty Publications and Presentations

This study explores, through a full factorial experimental design, the effects of graphite concentration and spray flow rate on the morphology, thickness, and tribological performance of graphite coatings for potential tribological applications. Coatings were applied to rough substrates using varying concentrations and flow rates, followed by analysis of their morphological characteristics, roughness, thickness, coefficient of friction (COF), and wear behavior. The results revealed distinct differences in the coating morphology based on flow rate, with low-flow-rate coatings exhibiting a porous structure and higher roughness, while high-flow-rate coatings displayed denser structures with lower roughness. A COF as low as 0.09 was achieved, …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …