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2024

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Articles 781 - 810 of 1004

Full-Text Articles in Materials Science and Engineering

Effect Of Post-Cured Through Thickness Reinforcement On Disbonding Behavior In Skin-Stringer Configuration, Jimesh D. Bhagatji, Christopher Morris, Yogaraja Sridhar, Bodhisatwa Bhattacharjee, Krishnanand N. Kaipa, Oleksandr G. Kravchenko Jan 2024

Effect Of Post-Cured Through Thickness Reinforcement On Disbonding Behavior In Skin-Stringer Configuration, Jimesh D. Bhagatji, Christopher Morris, Yogaraja Sridhar, Bodhisatwa Bhattacharjee, Krishnanand N. Kaipa, Oleksandr G. Kravchenko

Mechanical & Aerospace Engineering Faculty Publications

An experimental investigation of interlaminar toughness for post-cured through-thickness reinforcement (PTTR) skin-stringer sub-element is presented. The improvement in the crack resistance capability of skin-stringer samples was shown through experimental testing and finite element analysis (FEA) modeling. The performance of PTTR was evaluated on a pristine and initial-disbond of the skin-stringer specimen. A macro-scale pin-spring modeling approach was employed in FEA using a non-linear spring to capture the pin failure under the mixed-mode load. The experimental results showed a 15.5% and 20.9% increase in strength for the pristine-PTTR and initial-disbond PTTR specimens, respectively. The modeling approach accurately represents the overall structural …


Mechanisms Of Dendritic Shorting In Lithium Metal Batteries With Li7la3zr2o12 Solid Electrolytes, Lukas Karapin-Springorum Jan 2024

Mechanisms Of Dendritic Shorting In Lithium Metal Batteries With Li7la3zr2o12 Solid Electrolytes, Lukas Karapin-Springorum

Pomona Senior Theses

Energy storage will play a crucial role in efforts to mitigate the effects of climate change caused by greenhouse gas emissions from human activity. Lithium metal batteries using solid electrolytes like Li7La3Zr2O12 have higher energy density than lithium-ion batteries, which may enable a more rapid and complete electrification of transportation. However, lithium metal batteries suffer from undesirable short-circuiting when metallic lithium deposits connect the two electrodes. It has been debated whether these lithium dendrites generally grow directionally from the anode or are generated by the reduction of lithium ions inside the solid electrolyte, …


B(C₆F₅)₃ Co-Catalyst Promotes Unconventional Halide Abstraction From Grubbs I To Enhance Reactivity And Limit Decomposition, Austin W. Medley, Diya Patel, Calvin Utne, Trandon A. Bender Jan 2024

B(C₆F₅)₃ Co-Catalyst Promotes Unconventional Halide Abstraction From Grubbs I To Enhance Reactivity And Limit Decomposition, Austin W. Medley, Diya Patel, Calvin Utne, Trandon A. Bender

Chemistry & Biochemistry Faculty Publications

Ruthenium based Grubbs metathesis has become a commonplace reaction for synthetic chemists. Development of new generations of catalysts evolving from Grubbs I (GI) have led to greater stability, functional group compatibility, and superior reactivities. However, these advancements lead to increased costs. To this end, we report here how the addition of the commercially available tris(pentafluorophenyl)borane Lewis acid, which has become a common place catalyst in its own right, leads to enhanced reactivity of GI. Moreover, the increased reactivity arises via halide abstraction rather than traditional phosphine dissociation, providing ring-opening metathesis polymerization products that are divergent from those synthesized without the …


The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker Jan 2024

The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker

Theses and Dissertations--Chemical and Materials Engineering

Since the dawn of civilization, the use of metals has played an integral role in the evolution of human society. Over the years, and with the introduction of new engineering and science, we have learned how to combine metals to create new metallic systems. We have expanded our understanding of dealloying and chemical reactions, and, in doing so, we created nanoporous metals. Our use of metals has evolved from basic alloys such as bronze and steel to more complex alloys such as multi-principal element alloys. Nanoporous gold is an advanced metallic system that can be created through the dealloying process. …


Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser Jan 2024

Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser

Theses and Dissertations--Chemical and Materials Engineering

High Entropy Alloys (HEAs), also known as Multiprincipal Element Alloys (MPEAs), represent a paradigm shift in alloy design. Unlike traditional practices that limit compositions to the edges of phase diagrams, HEAs exploit equiatomic mixing of five or more elements at the center of phase diagrams to maximize configurational entropy. This unconventional approach exponentially expands the spectrum of potential alloy compositions, rendering conventional experimental methods inadequate for exploring this extensive compositional space.

In response to these challenges, the scientific community has shown a growing interest in high-throughput techniques, encompassing both computational and experimental domains. Particularly, Refractory High Entropy Alloys (RHEAs) have …


Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney Jan 2024

Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney

Theses and Dissertations--Chemical and Materials Engineering

The adoption of additive manufacturing across a wide range of fields is ever-increasing, allowing for solutions that were previously impossible to achieve. This dissertation demonstrates the wide range of macro- and micro- characterization techniques used to investigate several precipitation strengthened AM alloy systems. While AM allows for nearly unlimited design freedom, this brings along its own issues as the interplay between scan strategy and part geometry is less well known. In this work, a novel thin-wall dogbone geometry was utilized to study one type of complex geometry observed in a large portion of AM focused designs. The mechanical behavior of …


Optoelectrical Properties And Photostability Of Cspbbr3 Quantum Dots: Effects Of Dopants And Ligands, Md Shad Bin Salam Jan 2024

Optoelectrical Properties And Photostability Of Cspbbr3 Quantum Dots: Effects Of Dopants And Ligands, Md Shad Bin Salam

Theses and Dissertations--Chemical and Materials Engineering

Metal halide perovskite QDs have a great potential for displays and lighting because of their exceptional optoelectronic characteristics associated with quantum confinement effect. However, the stability in the environment during the applications of halide perovskite QDs remains a significant challenge, impeding their practicality and lowering their commercial scalability. High-temperature methods are well-established for producing doped perovskite QDs, the influence of room-temperature synthesis on thermal, size-dependent optical properties, and long-term stability remains inadequately understood. Also, there is a demand for strategies to increase the absorption of light, reduce trap states, and modify the energy levels of perovskite QDs.

In this study, …


Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier Jan 2024

Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier

Theses and Dissertations--Earth and Environmental Sciences

Calcium sulfoaluminate (CSA) was developed in part to lessen the environmental impact of cementitious materials compared to traditional Portland cements. CSA was first put into production in the 1970s and has been undergoing various performance testing to investigate its durability. Yet to be evaluated is CSA’s response to a rapid, high temperature event. In this study, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometry and scanning electron microscope imaging were used to analyze alterations in the mineralogy due to such an event. As found in previous studies, after ~125°C, ettringite has been completely dehydrated. Ettringite decomposes into bassanite and calcium …


Mechanochemical Synthesis Of Halide Perovskite Microcrystals, Xuan Huang Jan 2024

Mechanochemical Synthesis Of Halide Perovskite Microcrystals, Xuan Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Halide perovskites have emerged as a promising class of materials for various optoelectronic applications, including light-emitting diodes (LEDs), solar cells, photodetectors, and lasers, owing to their exceptional photophysical properties and ease of synthesis. Lead-based halide perovskites, despite their success, raise concerns regarding environmental toxicity, necessitating the exploration of lead-free alternatives. This thesis explores the synthesis and characterization of lead-free halide perovskites, focusing on tin-based variants, using a mechanochemical approach, which eliminates the use of toxic solvents and offers a sustainable synthesis route.

By employing a solventless mechanochemical method, lead-free tin-based halide perovskite microcrystals were successfully synthesized. This approach not only …


A Simple, Inexpensive Alkaline Method For Bacterial Dna Extraction From Environmental Samples For Pcr Surveillance And Microbiome Analyses, Abdulkarim Shwani, Bin Zuo, Adnan Alrubaye, Jiangchao Zhao, Douglas D. Rhoads Jan 2024

A Simple, Inexpensive Alkaline Method For Bacterial Dna Extraction From Environmental Samples For Pcr Surveillance And Microbiome Analyses, Abdulkarim Shwani, Bin Zuo, Adnan Alrubaye, Jiangchao Zhao, Douglas D. Rhoads

Poultry Science Faculty Publications and Presentations

DNA extraction for downstream molecular diagnostic applications can be an expensive, time-consuming process. We devised a method to quickly extract total bacterial DNA from environmental samples based on the sodium hydroxide lysis of cells with or without capture by magnetic beads for subsequent PCR or quantitative PCR. The final DNA extraction method using NaOH is extremely low-cost and can be completed in as little as 10 min at room temperature with dilution, or the DNA can be further purified using silica-coated paramagnetic beads. NaOH extraction was effective for Gram-negative and Gram-positive bacteria in samples from air, soil, sewage, food, laboratory …


Heating Capacity And Biocompatibility Of Hybrid Nanoparticles For Magnetic Hyperthermia Treatment, Aline Alexandrina Gomes, Thalita Marcolan Valverde, Vagner De Oliveira Machado, Emanueli Do Nascimento Da Silva, Daniele Alves Fagundes, Fernanda De Paula Oliveira, Erico Freitas, José Domingos Ardisson, José Maria Da Fonte Ferreira, Junnia Alvarenga De Carvalho Oliveira, Eliza Rocha Gomes, Caio Fabrini Rodrigues, Alfredo Miranda De Goes, Rosana Zacarias Domingues, Ângela Leão Andrade Jan 2024

Heating Capacity And Biocompatibility Of Hybrid Nanoparticles For Magnetic Hyperthermia Treatment, Aline Alexandrina Gomes, Thalita Marcolan Valverde, Vagner De Oliveira Machado, Emanueli Do Nascimento Da Silva, Daniele Alves Fagundes, Fernanda De Paula Oliveira, Erico Freitas, José Domingos Ardisson, José Maria Da Fonte Ferreira, Junnia Alvarenga De Carvalho Oliveira, Eliza Rocha Gomes, Caio Fabrini Rodrigues, Alfredo Miranda De Goes, Rosana Zacarias Domingues, Ângela Leão Andrade

Michigan Tech Publications

Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity …


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

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

Mechanical and Aerospace Engineering Faculty Research & Creative Works

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


Structural And Magnetic Properties Of Molecular Beam Epitaxy (Mnsb2te4)X(Sb2te3)1−X Topological Materials With Exceedingly High Curie Temperature, Candice R. Forrester, Christophe Testelin, Kaushini Wickramasinghe, Ido Levy, Dominique Demaille, David Hrabovsky, Xiaxin Ding, Lisa Krusin-Elbaum, Gustavo Lopez, Maria C. Tamargo Jan 2024

Structural And Magnetic Properties Of Molecular Beam Epitaxy (Mnsb2te4)X(Sb2te3)1−X Topological Materials With Exceedingly High Curie Temperature, Candice R. Forrester, Christophe Testelin, Kaushini Wickramasinghe, Ido Levy, Dominique Demaille, David Hrabovsky, Xiaxin Ding, Lisa Krusin-Elbaum, Gustavo Lopez, Maria C. Tamargo

Publications and Research

Tuning the properties of magnetic topological materials is of interest to realize exotic physical phenomena, new quantum phases and quasiparticles, and topological spintronic devices. However, current topological materials exhibit Curie temperature (TC) values far below those needed for practical applications. In recent years, significant progress has been made to control and optimize TC, particularly through defect-engineering of these structures. Most recently, we reported TC values up to 80 K for (MnSb2Te4)x(Sb2Te3)1−x when 0.7 ≤ x ≤ 0.85 by controlling the composition x and the …


Ultra-Fast Annealing Improves Snr And Long-Term Stability Of A Highly Multiplexed Line-By-Line Fbg Array Inscribed By Femtosecond Laser In A Coreless Fiber For Extreme-Temperature Applications, Farhan Mumtaz, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang Jan 2024

Ultra-Fast Annealing Improves Snr And Long-Term Stability Of A Highly Multiplexed Line-By-Line Fbg Array Inscribed By Femtosecond Laser In A Coreless Fiber For Extreme-Temperature Applications, Farhan Mumtaz, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This study reports the fabrication of an 4th-order line-by-line Fiber Bragg Gratings (FBG) array using femtosecond laser inscription within a highly multimode coreless optical fiber, with a particular focus on achieving substantial multiplexing capabilities. An ultra-fast annealing procedure is employed, resulting in an impressive enhancement of the FBG sensor's fringe visibility by approximately 13 dB, signifying a notable improvement of approximately ~4 dB. This substantial enhancement contributes to the long-term stability and performance of the multiplexed FBG array in extreme temperature conditions. The systematic fabrication approach employed for the multiplexed FBG array guarantees a high signal-to-noise ratio (SNR) for each …


Halide-Assisted Growth Of Transition Metal Dichalcogenides, Vinaayak Sivam Balasubramaniam Jan 2024

Halide-Assisted Growth Of Transition Metal Dichalcogenides, Vinaayak Sivam Balasubramaniam

Dissertations, Master's Theses and Master's Reports

Monolayers of transition metal dichalcogenides (TMDCs) have attracted significant attention as the rare two-dimensional (2D) semiconducting materials with a direct energy band gap. Chemical vapour deposition (CVD) is one of the scalable techniques to grow atomically thin TMDC monolayers in high quality, but it requires high growth temperature. Herein we report the growth of MoS2, WS2 and MoSe2 by a one-step halide-assisted CVD method using NaCl and KCl as the catalysts. These halides could reduce the growth temperature of TMDCS by reacting with the precursors (TMDC powders) to form volatile intermediate compounds as the growth species. We use optical microscopy, …


Fatigue Resistant Cast Steel Railcar Couplers Produced By Wire-Arc Additive Manufacturing (Waam), Samuel Vellequette Jan 2024

Fatigue Resistant Cast Steel Railcar Couplers Produced By Wire-Arc Additive Manufacturing (Waam), Samuel Vellequette

Dissertations, Master's Theses and Master's Reports

Every year, approximately 90,000 cast steel railcar coupler knuckles are replaced preemptively to avoid fatigue failure. The coupler geometry has been in service since the early 1930s, so geometry changes are restricted to maintain compatibility with the existing fleet. Defects from the casting process, decarburization during heat treatment, and in-service exposure to corrosive environments combine to promote fatigue crack nucleation in high-stress regions of the knuckle. Wire-arc additive manufacturing (WAAM), which uses traditional welding techniques to build material to near-net shapes, was employed to deposit higher-strength materials in critical regions. By replacing the cast steel in the high-stress region of …


Calculation Of Elastic Constants Of Bulk Metallic Glasses From Indentation Tests, Zhitong Xu, Ming Liu, Fuqian Yang Jan 2024

Calculation Of Elastic Constants Of Bulk Metallic Glasses From Indentation Tests, Zhitong Xu, Ming Liu, Fuqian Yang

Chemical and Materials Engineering Faculty Publications

One of the challenges in the applications of instrumented indentation is to simultaneously measure elastic modulus and Poisson’s ratio of homogeneous, isotropic materials. This work proposes empirical equations for simultaneous calculation of elastic modulus and Poisson’s ratio of bulk metallic glasses (BMGs) from the ratio of the short diagonal length to the long diagonal length and the area of the Knoop imprint. The parameters pre- sented in the empirical equations are determined first by Knoop microhardness tests of 24 BMGs, whose elastic moduli and Poisson’s ratios are measured by resonant ultrasound spectroscopy. These empirical equations are further validated by the …


“Zero” Porosity High Loading Nmc622 Positive Electrodes For Li-Ion Batteries, Haidar Y. Alolaywi, Kubra Uzun, Yang-Tse Cheng Jan 2024

“Zero” Porosity High Loading Nmc622 Positive Electrodes For Li-Ion Batteries, Haidar Y. Alolaywi, Kubra Uzun, Yang-Tse Cheng

Chemical and Materials Engineering Faculty Publications

LiNi0.6 Mn0.2Co0.2 O 2 (NMC622) is a widely used positive electrode material for lithium-ion batteries, including electric vehicles. In this work, we investigated the effects of porosity, ranging from “zero” to the typical 35%, on the electrochemical behavior of high- loading NMC622 electrodes. Although it is well known that the energy density of the electrode increases with increasing areal capacity and decreasing porosity, NMC-positive electrodes with exceedingly low porosity (e.g., near zero) and high loading (e.g., 4 mAh cm−2 ) have not been investigated. Here, we report an intriguing observation that the “zero porosity” NMC electrode can have higher capacity …


Spark Plasma Sintering Of Magnesium Titanate Ceramics, Suzana Filipović, Nina Obradović, William G. Fahrenholtz, Steven Smith, Miljana Mirković, Adriana Peleš Tadić, Jovana Petrović, Antonije Đorđević Jan 2024

Spark Plasma Sintering Of Magnesium Titanate Ceramics, Suzana Filipović, Nina Obradović, William G. Fahrenholtz, Steven Smith, Miljana Mirković, Adriana Peleš Tadić, Jovana Petrović, Antonije Đorđević

Materials Science and Engineering Faculty Research & Creative Works

Magnesium titanate ceramics were prepared by reactive spark plasma sintering (SPS) at 1200 °C for 5 min. Prior to sintering, MgO and TiO2 powders were mixed by high energy ball milling (HEBM) for 15, 30, or 60 min. The effect of milling time on phase composition was analyzed by X-ray diffraction (XRD) for milled powders and sintered specimens. The morphology of the sintered ceramics was investigated by scanning electron microscopy (SEM), while elemental distribution was determined by energy dispersive spectroscopy (EDS). The presence of the MgTi2O5 phase was detected in XRD and was confirmed by EDS analysis. Microcracking was …


Degree Of Dispersion/Exfoliation And Surface Functionalization Of 1d And 2d Carbon Nanostructured Materials: Interface Interactions And Effects On Mechanical Properties, Michail Margas Jan 2024

Degree Of Dispersion/Exfoliation And Surface Functionalization Of 1d And 2d Carbon Nanostructured Materials: Interface Interactions And Effects On Mechanical Properties, Michail Margas

Material Science and Engineering Dissertations - Archive

The development of advanced cementitious nanocomposites relies heavily on understanding the interfacial interactions between carbon-based nanomaterials and the cement matrix, which significantly influence the material’s performance. The goal of this dissertation is to investigate the effect of dispersion/exfoliation and surface functionalization of 1D multiwall carbon nanotubes (MWCNTs), carbon nanofibers (CNFs), and 2D graphene nanoplatelets (GNPs) in aqueous suspensions on the interface interactions of nanoengineered cementitious composites. The first objective of this dissertation is to quantitatively evaluate the degree of nanomaterial dispersion for MWCNT and CNF suspensions, in a converging manner for cement-based materials applications using spectroscopic techniques, such as UV-vis …


Development Of Synthetically Accessible Glycolated Polythiophenes For High-Performance Organic Electrochemical Transistors, Bowen Ding, Vianna N. Le, Hang Yu, Guanchen Wu, Adam V. Marsh, Edgar Gutiérrez-Fernández, Nicolás Ramos, Martina Rimmele, Jaime Martín, Jenny Nelson, Alexandra F. Paterson, Martin Heeney Jan 2024

Development Of Synthetically Accessible Glycolated Polythiophenes For High-Performance Organic Electrochemical Transistors, Bowen Ding, Vianna N. Le, Hang Yu, Guanchen Wu, Adam V. Marsh, Edgar Gutiérrez-Fernández, Nicolás Ramos, Martina Rimmele, Jaime Martín, Jenny Nelson, Alexandra F. Paterson, Martin Heeney

Chemical and Materials Engineering Faculty Publications

Four glycolated polythiophene-based organic mixed ionic-electronic conductors (OMIECs), PE2gTT, PE2gT, PT2gTT, and PT2gT are prepared by atom-efficient direct arylation polymerization, avoiding the need for toxic organometallic pre- cursors. PE2gT, PT2gTT, and PT2gT are operable in p-type accumulation mode organic electrochemical transistors (OECTs), with PT2gT displaying the best device performance with a μC* product figure-of-merit of 290 F cm−1 V−1 s−1 . A record volumetric capacitance among p-type glycolated polythiophene OMIECs of 313 F cm−3 is observed for PE2gT, ascribed to the high proportion- ality of polar components in its materials design. The good OECT performance of PE2gT with μC* = …


The Integrated Behavioral Model Of Mental Health Help Seeking (Ibm-Hs): A Health Services Utilization Theory Of Planned Behavior For Accessing Care, Joseph H. Hammer, David L. Vogel, Patrick R. Grzanka, Nayeon Kim, Brian T. Keum, Claire Adams, Sarah A. Wilson Jan 2024

The Integrated Behavioral Model Of Mental Health Help Seeking (Ibm-Hs): A Health Services Utilization Theory Of Planned Behavior For Accessing Care, Joseph H. Hammer, David L. Vogel, Patrick R. Grzanka, Nayeon Kim, Brian T. Keum, Claire Adams, Sarah A. Wilson

Chemical and Materials Engineering Faculty Publications

This article introduces the integrated behavioral model of mental health help seeking (IBM-HS), a theoretical model for understanding the constructs (e.g., systemic, predisposing, and enabling factors; mental health literacy; illness perceptions; perceived need; stigma; shame; perceived benefits, motivation) that influence people’s decision making around seeking professional mental health care and their ultimate access to formal treatment. The IBM-HS is a help-seeking-specific adaptation of the empirically supported integrated behavioral model and integrative model, which are themselves evolutions of the theory of planned behavior and theory of reasoned action. The IBM-HS posits that help-seeking determinants (e.g., structural forces; cultural influences; past help-seeking …


Investigation Of The Effect Of Preparation Parameters On The Structural And Mechanical Properties Of Gelatin/Elastin/Sodium Hyaluronate Scaffolds Fabricated By The Combined Foaming And Freeze-Drying Techniques, Mansour Qamash, S. Misagh Imani, Meisam Omidi, Ciara Glancy, Lobat Tayebi Jan 2024

Investigation Of The Effect Of Preparation Parameters On The Structural And Mechanical Properties Of Gelatin/Elastin/Sodium Hyaluronate Scaffolds Fabricated By The Combined Foaming And Freeze-Drying Techniques, Mansour Qamash, S. Misagh Imani, Meisam Omidi, Ciara Glancy, Lobat Tayebi

Electrical & Computer Engineering Faculty Publications

This paper aimed to evaluate the effects of different preparation parameters, including agitation speed, agitation time, and chilling temperature, on the structural and mechanical properties of a novel gelatin/elastin/sodium hyaluronate tissue engineering scaffold, recently developed by our research group. Fabricated using a combination of foaming and freeze-drying techniques, the scaffolds were assessed to understand how these parameters influence their morphology, internal microstructure, porosity, mechanical properties, and degradation behavior. The fabrication process used in this study involved preparing a homogeneous aqueous solution containing 8% gelatin, 2% elastin, and 0.5% sodium hyaluronate (w/v), which was then subjected to mechanical agitation at speeds …


Control Of Flow Instabilities With Acoustic Metamaterials, Jensen E. Mctighe Jan 2024

Control Of Flow Instabilities With Acoustic Metamaterials, Jensen E. Mctighe

Open Access Master's Theses

Acoustic metamaterials (AMs) have been proposed for uses in flow control, as they offer a passive control method and can be engineered independently, without needing complex fluid structure interactions simulations. For example, AMs embedded into flat plate surfaces have been demonstrated to delay (or speed up) the onset of laminar-to-turbulent boundary layer transition by attenuating (or strengthening) Tollmein-Schlicting waves through numerical simulation. However, as of present, no experimental research has been conducted to study or demonstrate the behaviors of AMs designed to interact with flow structures. An experiment was performed in which an AM was embedded into a flat plate …


Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of CoMRhsi (M = Cr, Mn) Quaternary Heusler Alloys, Abdullah Hzzazi, Hind Alqurashi, Eesha Andharia, Bothina Hamad, M. O. Manasreh Jan 2024

Theoretical Investigations Of The Structural, Dynamical, Electronic, Magnetic, And Thermoelectric Properties Of CoMRhsi (M = Cr, Mn) Quaternary Heusler Alloys, Abdullah Hzzazi, Hind Alqurashi, Eesha Andharia, Bothina Hamad, M. O. Manasreh

Physics Faculty Publications and Presentations

The structural, dynamical, electrical, magnetic, and thermoelectric properties of CoMRhSi (M = Cr, Mn) quaternary Heusler alloys (QHAs) were investigated using density functional theory (DFT). The Y-type-II crystal structure was found to be the most stable configuration for these QHAs. Both CoCrRhSi and CoMnRhSi alloys possess a half-metallic behavior with a 100% spin-polarization as the majority spin channel is metallic. On the other hand, the minority spin channel is semiconducting with narrow indirect band gaps of 0.54 eV and 0.57 eV, respectively, along the Γ−𝑋 high symmetry line. In addition, both CoCrRhSi and CoMnRhSi alloys possess a ferromagnetic structure …


Effect Of Strain Profiling On Anisotropic Opto-Electronic Properties Of As2X3 (X =S, Te) Monolayers From First Principles, Eesha Andharia, Hind Alqurashi, Ihsan Erikat, Bothina Hamad, M. O. Manasreh Jan 2024

Effect Of Strain Profiling On Anisotropic Opto-Electronic Properties Of As2X3 (X =S, Te) Monolayers From First Principles, Eesha Andharia, Hind Alqurashi, Ihsan Erikat, Bothina Hamad, M. O. Manasreh

Physics Faculty Publications and Presentations

Strain Engineering is a widely adopted approach to modulate the opto-electronic performance of 2-Dimensional (2D) materials. Recently, anisotropic Van der Waals (vdW) based 2D As2S3 monolayer has gained significant attention within the scientific community due to its stability in ambient conditions. Similar compounds like As2Te3 have also been theoretically explored. However, its indirect bandgap nature limits its application in optical devices. In this study, a systematic study of compressive and tensile strain on three profiles–Uniaxial along a-axis, Uniaxial along b-axis and biaxial strain from −10% to +10%, is performed for As2S3 …


F-Temper Vs O-Temper Brazing Of 3003 Aluminum Return Bends, Mieka R. Clark Jan 2024

F-Temper Vs O-Temper Brazing Of 3003 Aluminum Return Bends, Mieka R. Clark

Dissertations, Master's Theses and Master's Reports

As-extruded (F-temper) 3003 return bends can provide cost savings over annealed (O-temper) return bends in aluminum heat exchangers. To assess if F-temper return bends are an alternative to the baseline O-temper bends, the grain structure, bending performance, and melting behavior were assessed through:

  • Quantifying the effect of dispersoids on recrystallization
  • Tracking bending behavior through grain morphology and surface texture
  • Measuring the number and volume fraction of the α-Al(Mn,Fe)Si intermetallic
  • Inducing incipient melting through high temperature thermal exposure.

When homogenized at 620°C and 630°C, the F-temper bends had no orange peel texture, the grain size was equivalent to the annealed product, …


Machine Learning For Electronic Structure Prediction, Shashank Pathrudkar Jan 2024

Machine Learning For Electronic Structure Prediction, Shashank Pathrudkar

Dissertations, Master's Theses and Master's Reports

Kohn-Sham density functional theory is the work horse of computational material science research. The core of Kohn-Sham density functional theory, the Kohn-Sham equations, output charge density, energy levels and wavefunctions. In principle, the electron density can be used to obtain several other properties of interest including total potential energy of the system, atomic forces, binding energies and electric constants. In this work we present machine learning models designed to bypass the Kohn-Sham equations by directly predicting electron density. Two distinct models were developed: one tailored to predict electron density for quasi one-dimensional materials under strain, while the other is applicable …


Investigation Of Space Charge Effects On Co2 Electrocatalytic Reduction On Gd-Doped Ceria Via Scanning Kelvin Probe And Model-Based Bayesian Analysis, Alejandro Mejia Jan 2024

Investigation Of Space Charge Effects On Co2 Electrocatalytic Reduction On Gd-Doped Ceria Via Scanning Kelvin Probe And Model-Based Bayesian Analysis, Alejandro Mejia

Graduate Theses, Dissertations, and Problem Reports (ETD)

In studying novel energy conversion and storage systems, such as high-temperature electrolysis, numerous underlying fundamental physical processes remain unclear or inadequately understood. Among these, the modeling and comprehension of surface reaction mechanisms, coupled with the intricate effects of space‑charge interfaces, remains an unclear and challenging area of research.

The work of this dissertation involves the development of a 2D finite element analysis model, leveraging the robust MOOSE framework from INL. This model, featuring inhomogeneous defect thermodynamics for near-surface chemistry, formulated through Poisson‑Cahn variational theory, has been exploited for studying the electrocatalytic reduction of CO2 on gadolinia doped ceria. The …


Data-Driven Modeling Of Oxygen Kinetics In La0.6sr0.4co0.2fe0.8o3−Δ (Lscf) For High-Temperature Reduction Of Co2 In An Electrolysis Cell, Ferron Campbell Jan 2024

Data-Driven Modeling Of Oxygen Kinetics In La0.6sr0.4co0.2fe0.8o3−Δ (Lscf) For High-Temperature Reduction Of Co2 In An Electrolysis Cell, Ferron Campbell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Electrolysis systems are critical to several societal applications, particularly energy storage and conversion. Developing these systems requires a detailed knowledge of the chemistry and thermodynamics of the materials used in the electrolysis cell. This work focuses on using embedded scientific machine learning as an efficient way to build an interpretable model for the reaction and transport kinetics in the LSCF electrode, whose performance directly influences the electrolysis system’s performance. The models developed in this study are trained using the publicly available machine learning package, FoKL-GP. This package incorporates a robust Gibbs sampler that employs a forward variable selection process to …