Materials Science and Engineering Commons^™

Theoretical Model Of Femtosecond Coherence Spectroscopy Of Vibronic Excitons In Molecular Aggregates, Alexander J. Rode, Paul C. Arpin, Daniel B. Turner

Materials Science and Engineering Faculty Publications and Presentations

When used as pump pulses in transient absorption spectroscopy measurements, femtosecond laser pulses can produce oscillatory signals known as quantum beats. The quantum beats arise from coherent superpositions of the states of the sample and are best studied in the Fourier domain using Femtosecond Coherence Spectroscopy (FCS), which consists of one-dimensional amplitude and phase plots of a specified oscillation frequency as a function of the detection frequency. Prior works have shown ubiquitous amplitude nodes and π phase shifts in FCS from excited-state vibrational wavepackets in monomer samples. However, the FCS arising from vibronic-exciton states in molecular aggregates have not been …

Hardness Of Single Phase High Entropy Carbide Ceramics With Different Compositions, Paul M. Brune, Gregory E. Hilmas, William G. Fahrenholtz, Jeremy Lee Watts, Caillin J. Ryan, Chris M. Desalle, Douglas E. Wolfe, Stefano Curtarolo

Materials Science and Engineering Faculty Research & Creative Works

Five High Entropy Carbide Ceramics, (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C, (Cr0.2,Hf0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Mo0.2,Ta0.2,Ti0.2,Zr0.2)C, (Hf0.2,Ta0.2,Ti0.2,W0.2,Zr0.2)C, and (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C, Were Synthesized by Carbothermal Reduction of Oxides and Direct Current Sintering. the Five High Entropy Carbide Ceramics Were Determined to Be Nominally Phase-Pure with Relative Densities of More Than 98.9% and Mean Grain Sizes of Less Than 5 Μm. Average Vickers Hardness Values Ranged from 19.2 ± 0.4 GPa for (Hf0.2,Nb0.2,Ta0.2,Ti0.2,Zr0.2)C at a Load of 2 Kgf to 43.5 ± 0.4 GPa for (Hf0.2,Mo0.2,Ti0.2,W0.2,Zr0.2)C at a Load of 0.05 Kgf. Hardness Generally Increased with Increasing the Valence Electron Concentration and Strain as Measured by the Williamson-Hall Analysis. However, Neither …

Towards A Practical Method For Monitoring Kinetic Processes In Polymers With Low-Frequency Raman Spectroscopy, Robert Vito Chimenti

Theses and Dissertations

Unlike liquids and crystalline solids, glassy materials exist in a constant state of structural nonequilibrium. Therefore, a comprehensive understanding of material kinetics is critical for understanding the structure-property-processing relationships of polymeric materials. Amorphous materials universally display low-frequency Raman features related to the phonon density of states resulting in a broad disorder band for Raman shifts below 100 cm-1, which is related to the conformational entropy and the modulus. This disorder band is dominated by the Boson peak, a feature due to phonon scattering because of disorder and can be related to the transverse sound velocity of the material, and a …

Low Impedance, Durable, Self-Adhesive Hydrogel Epidermal Electrodes For Electrophysiology Recording, Naiyan Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional electrodes used for electrophysiology recording, characterized by their hard, dry, and inanimate nature, are fundamentally mismatched with the soft, moist, and bioactive characteristics of biological tissues, leading to suboptimal skin-electrode interfaces. Hydrogel materials, mirroring the high water content and biocompatibility of biological tissues, emerge as promising candidates for epidermal electronic materials due to their adjustable physicochemical properties. However, challenges such as inadequate electrical conductivity, elevated skin impedance, unreliable adhesion in moist conditions, and performance decline from dehydration have significantly restricted the efficacy and applicability of hydrogel-based electrodes. In this thesis, we report a high-performance hydrogel epidermal electrode patch for …

Deep Selenium Donors In Zngep2 Crystals: An Electron Paramagnetic Resonance Study Of A Nonlinear Optical Material, Timothy D. Gustafson, Larry E. Halliburton, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, J. Jesenovec, Kent L. Averett, Jonathan E. Slagle [*]

Faculty Publications

Zinc germanium diphosphide (ZnGeP₂) is a ternary semiconductor best known for its nonlinear optical properties. A primary application is optical parametric oscillators operating in the mid-infrared region. Controlled donor doping provides a method to minimize the acceptor-related absorption bands that limit the output power of these devices. In the present study, a ZnGeP₂ crystal is doped with selenium during growth. Selenium substitutes for phosphorus and serves as a deep donor. Significant concentrations of native defects (zinc vacancies, germanium-on-zinc antisites, and phosphorous vacancies) are also present in the crystal. Electron paramagnetic resonance (EPR) is used to establish the …

Adopting Information System Technologies In Construction Project Management, Hadi Haikal

Harrisburg University Dissertations and Theses

The construction sector has remained late in integrated information systems' adopting process to perform the system improving processes. Lack of adoption of technology has been a root cause of the early issues they faced, such as budgetary and scheduling overshoots, quality defects, safety occurrences, and generally poor communication and coordination among the stakeholders. This research looks into the benefits and challenges, the key success factors, and the implications of using an array of information systems, including building information modeling (BIM), artificial intelligence (AI), Internet of Things (IoT) sensing, and enterprise systems, to comprehensively address issues in project management in construction …

Processing And Testing Commodity And Engineering Cfrtp Composites, Delia M. Derner, Kristine Osorio

Research & Creative Achievement Day

Commodity thermoplastic polymers provide good load transfer to and protection of the reinforcing fibers.  However, their mechanical properties are inferior to high-performance thermoplastic polymer composites.  Findings of preliminary research conducted at WSU showed that continuous fiber reinforced (CFR) commodity polymers such as PETG and PP have better Izod impact resistance than their high-performance CFR counterparts.  Further investigation of these findings is conducted in this research project.  Quasi-isotropic laminates of GF/PETG and GF/PET-am are fabricated and tested in drop weight impact.  The results will be compared with previously determined results of high-performance CF/PPS, CF/PA12 and GF/PPS.  The samples are fabricated using …

Low-Velocity Drop Weight Impact And Compression After Impact Properties Of Symmetric Quasi-Isotropic Cfrtp Composites, Youyi Zhou, Kyungbin Min

Research & Creative Achievement Day

Low-velocity impact properties and residual compression strength after impact performance are used to evaluate composite materials for many applications. In this research, low-velocity drop-weight impact and compression after impact performance of four continuous fiber reinforcement thermoplastic (CFRTP) composites are investigated. Quasi-isotropic samples of GF/PP, CF-PA12, CF-PA6, GF-PA6 were fabricated and tested according to ASTM standards. Three energy levels of 10, 15, and 20 J/mm, were employed in this research. Results indicate that GF/PP exhibits the highest damage resistance and rebound-ability, evidenced by its minimal indentation and damage area, the highest significant damage threshold force, and the highest ratio of impact …

Ergo Carbon Workspace, Ethan C. Atkinson, Joshua N. Hanner, Rachel A. Henderson, Anders Nielsen, Mohamed A. Salat

Research & Creative Achievement Day

The goal of the Ergo Carbon Workspace is to create a monitor stand that is both lightweight and easily transportable, catering to the needs of modern workspaces. Constructed from carbon fiber, epoxy resin, and a honeycomb core, this design emphasizes portability without sacrificing durability. Incorporating aerospace-grade honeycomb core as well as braided carbon fiber epoxy struts bolsters structural integrity while maintaining a lightweight part. The Ergo Carbon Workspace design facilitates effortless assembly and disassembly, simplifying transportation and packaging. Through the utilization of composite materials, the stand achieves an optimal balance of strength and portability. Ergo Carbon Workspace will also incorporate …

Mechanical Characterization Of Hemp, Jute, And Flax Based Natural Fibre Composites For Non-Structural Applications In Aircraft And Automobiles, Ravi Kumar B

Theses and Dissertations

Demand for reducing energy consumption and detrimental environmental impacts after the effective lifetime of an engineering material are the major driving factors for the development of natural fibre reinforced composites (NFRCs) in various sectors. Compared to synthetic fibre like carbon-fibres or Kevlar, natural fibres provide several benefits including light weight, inexpensive, recyclability, superior specific strength, biodegradable, non-toxic during handling, and less energy intensive during manufacturing. This doctoral work presents observations from mechanical tests and interpretations on the suitability of natural fibre reinforced composites for less heavily loaded engineering applications areas.

In the first stage, jute, flax, and hemp fibres were …

Achieving Room Temperature Plasticity In Brittle Ceramics Through Elevated Temperature Preloading, Chao Shen, Jin Li, Tongjun Niu, Jaehun Cho, Zhongxia Shang, Yifan Zhang, Anyu Shang, Bo Yang, Ke Xu, R. Edwin Garcia, Haiyan Wang, Xinghang Zhang

Purdue University Libraries Open Access Publishing Fund

Ceramic materials with high strength and chemical inertness are widely used as engineering materials. However, the brittle nature limits their applications as fracture occurs before the onset of plastic yielding. There has been limited success despite extensive efforts to enhance the deformability of ceramics. Here we report a method for enhancing the room temperature plastic deformability of ceramics by artificially introducing abundant defects into the materials via preloading at elevated temperatures. After the preloading treatment, single crystal (SC) TiO2 exhibited a substantial increase in deformability, achieving 10% strain at room temperature. SC α-Al2O3 also showed plastic deformability, 6 to 7.5% …

Detection Of Endocrine-Disrupting Chemicals In Personal Care Products Using A Polyhedral Oligomeric Silsesquioxane-Based Hybrid Material, Aarthi K

Theses and Dissertations

Personal care products (cosmetics) are a diverse group of goods, that includes all the essential routines including the personal hygiene products used in our day-to-day life. It contains a variety of ingredients in its formulation, including preservatives, flavor, UV filters, and other additives. Few of the chemicals utilized are found to impair human health and have serious environmental impacts. The major chemicals include parabens, triclosan, oxybenzone, phthalates, heavy metals, fragrances, etc, Though the Scientific Committee on Consumer Safety (SCCS) has set the usage limits for the chemicals used, exposure to these chemicals from multiple products may exceed the exposure limit. …

Application Of The Immobilized Low-Activity Waste Glass Corrosion Model To The Static Dissolution Of 24 Statistically-Designed Alkali-Borosilicate Waste Glasses, Sebastien N. Kerisit, James J. Neeway, Charmayne E. Lonergan, Benjamin Parruzot, Jarrod V. Crum, Richard C. Daniel, Gary L. Smith, R. Matthew Asmussen

Materials Science and Engineering Faculty Research & Creative Works

Glass corrosion models that capture the complex mechanisms of the glass-water reaction enable the prediction of nuclear waste glass durability in disposal scenarios. Parameterization of such models is challenging because of the need to capture changes in corrosion behavior with time, reaction conditions, and glass composition. Here, we describe and employ the ILAW (immobilized low-activity waste) glass corrosion model (IGCM) in geochemical simulations of static dissolution tests, at two temperatures (40 °C and 90 °C), for a matrix of 24 enhanced low-activity waste (eLAW) glasses statistically designed to cover a processable composition space defined by 8 major glass components (Al …

Decoding Crystallization Behavior Of Aluminoborosilicate Glasses: From Structural Descriptors To Quantitative Structure – Property Relationship (Qspr) Based Predictive Models, Yingcheng Zhang, Marco Bertani, Alfonso Pedone, Randall E. Youngman, Gregory Tricot, Aditya Kumar, Ashutosh Goel

Materials Science and Engineering Faculty Research & Creative Works

Successful decoding of structural descriptors controlling the crystallization in multicomponent functional glasses can pave the way for the transition from the trial-and-error approach and empirical modeling for glass/glass-ceramic composition design toward more rational and scientifically rigorous Quantitative Structure-Property Relationship (QSPR) based models. However, due to the compositional and structural complexity of multicomponent glasses and the longer time and length scales associated with nucleation, the development and validation of QSPR models are still in it's infancy. The work presented in the article is an attempt to leap forward in this pursuit by combining the strengths of experimental and computational materials science …

Influence Of Eco-Friendly Agar-Derivatives On The Electrochemical Performance Of Carbon Felts Electrodes Of Vanadium Redox Flow Battery, Abdulmonem Fetyan, Ayoob Alhammadi, Zineb Matouk, Anugrah Andisetiawan, Ahmed Bahaa

All Works

In this study, bio-derived natural agar powder was used as an electrocatalyst for application as an electrode in all‑vanadium redox flow batteries. Different concentrations of agar solution were tested, and cyclic voltammetry studies confirmed that agar loaded felts have good catalytic activity toward both redox couples V4+/V5+ at the positive and V2+/V3+ at the negative side. Energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy demonstrated the presence of higher amount of oxygen-functional groups on the surface of the fibers. Contact angle measurements demonstrated an enormous increase in hydrophilicity of the felts treated with agar. Long-term charge/discharge profiles revealed 6 % …

Mechanical Characterization And Evaluation Of Additively Manufactured Titanium 5v-5mo-5al-3cr Alloy, Zachary Casias

Mechanical Engineering ETDs

Ti-5V-5Mo-5Al-3Cr (Ti-5553) is a near beta titanium alloy commonly used in aerospace applications. It is currently being explored for additive manufacturing (AM), but the fatigue behavior of this AM alloy needs to be well-understood for adoption in aerospace applications. The present work examines the tensile and fatigue behavior of LPBF manufactured Ti-5553. The effect of post-print heat treatments, effects of surface roughness, and print defects on the mechanical properties of AM Ti-5553 were also evaluated. Fatigue lives of as-LPBF and BAA material are nearly identical, and both are far below the fatigue lives of conventionally manufactured Ti-5553 of 350 MPa. …

Seeding Effects Of Submicron Caal-No3 Ldh Particles On The Hydration And Properties Of Portland Cement And Sulfoaluminate Cement Pastes, Sukanta K. Mondal, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Layered double hydroxide (LDH) is reported to improve the durability of concretes, primarily due to its ability to exchange anionic species, including chloride, which is implicated in corrosion-driven durability issues. However, there is no comprehensive study investigating the effect of LDH on the properties of different cement systems at both early and mature ages. in this study, the early age and mature age properties of Portland cement (OPC) and calcium sulfoaluminate (CSA) cement pastes seeded with submicron-sized calcium aluminum-NO3 LDH (CaAl-NO3 LDH) were investigated. the effects of the 1–5%mass dosage of LDH on the hydration of both cement systems were …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

Quasi-Static Compression Performance Of Three Subscale Origami-Inspired Carbon Fiber Reinforced Polymer, Chase Mortensen

Student Research Symposium

Sandwich-structured composites are made of a lightweight core material between two thin composite panels. Variants of the Ori-Miura folding pattern have been investigated and compared to both the traditional Miura folding pattern (Fig. 1) and the more commonly used core design, the honeycomb. While the honeycomb design is favored over the Miura folding pattern and its variants due to its simple shape and better performance in compression, honeycomb cores also present drawbacks that are detrimental to the integrity of the sandwich structure. These drawbacks include, but are not limited to:

• Honeycomb cores consist of closed channels trapping moisture and heat. …

The Aerodynamic Levitator Project, Noah Brown

Undergraduate Research Conference at Missouri S&T

After the development and successful demonstration of a hyperbaric aerodynamic levitator, work to redesign the nozzle was proposed for increasing levitation height and stability. The goal of this eight-week summer research project was to create a CFD model to aid in the optimization of this nozzle. This was to be accomplished by using ANSYS Fluent to first replicate experimental data found in a research paper to assess its validity. Next, the model was to be modified for use on the levitator project and then used to analyze the current nozzle design. Afterwards, Steps will be taken to make alterations to …