Materials Science and Engineering Commons^™

Variability In The Fabrication Process Of Bivo4 Photoanodes, Lauren M. Phillips

Senior Honors Projects, 2010-2019

Hydrogen gas produced from the photoelectrochemical (PEC) decomposition of water, using sunlight as an energy source, is a promising approach for sustainable fuel production. This decomposition of water is also called artificial photosynthesis. A device that accomplished this process is sometimes call an artificial leaf, which mimics nature inasmuch as it stores solar energy as a chemical fuel (e.g., hydrogen) by splitting water, in this way imitating natural photosynthesis. In 2009, Dr. Keith Holland and Dr. David Lawrence of James Madison University (JMU) initiated a research program to investigate materials for the photoelectrochemical decomposition of water into hydrogen and oxygen, …

Enhancing Grain Refinement Of Austenitic Steel With Ti Additions By Melt Treatment Sequence Optimization, Gun Ge, Semen Naumovich Lekakh, Ronald J. O'Malley

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Measuring The Effect Of Vegetated Roofs On The Performance Of Photovoltaic Panels In Combined Systems, Hamid Hawi Kadham Ogaili

Dissertations and Theses

Recent studies suggest that integration of photovoltaic panels with green roofs may improve the performance of both. While vegetation may provide a benefit by reducing the net radiation load on the underside of the photovoltaic (PV) panels, it may also affect convective cooling of panels, and consequently, panel efficiency. Both effects likely diminish with the height of the PV panel above the roof, although placing PV panels too close to the vegetation increases the risk of the plants growing over the edges of, and shading the PV panel. There is a gap in the literature with respect to evaluating these …

Section Abstracts: Astronomy, Mathematics And Physics With Material Science

Virginia Journal of Science

Abstracts of the Astronomy, Mathematics, and Physics with Material Science Section for the 93rd Annual Meeting of the Virginia Academy of Science, May 21-23, 2015, James Madison University, Richmond, Virginia

Comparison Of Low-Temperature Co-Fired Ceramic And Direct Bonded Copper For Single Ended Primary Inductance Topology, Kristopher Cody Johnson

Electrical Engineering Undergraduate Honors Theses

This work examines the thermal dissipation characteristics of Low-Temperature Co-fired Ceramic (LTCC) and Direct Bonded Copper (DBC) with the implementation of a Single Ended Primary Inductance Converter (SEPIC) topology. The advantages and disadvantages of the two substrates will be explored in addition to a description of the design and control of the SEPIC. It will be shown that the DBC implementation is superior with regards to thermal dissipation, but that LTCC has advantages in high- density packaging, RF applications, and embedded components. These substrates and converters provide many advantages in industrial applications that include automotive and grid level implementations. Additional …

Characterization Of Microstructure And Property Evolution In Advanced Cladding And Duct: Materials Exposed To High Dose And Elevated Temperature, Janelle P. Wharry

Materials Science and Engineering Faculty Publications and Presentations

Designing materials for performance in high-radiation fields can be accelerated through a carefully chosen combination of advanced multiscale modeling paired with appropriate experimental validation. The studies reported in this work, the combined efforts of six universities working together as the Consortium on Cladding and Structural Materials, use that approach to focus on improving the scientific basis for the response of ferritic–martensitic steels to irradiation. A combination of modern modeling techniques with controlled experimentation has specifically focused on improving the understanding of radiation-induced segregation, precipitate formation and growth under radiation, the stability of oxide nanoclusters, and the development of dislocation networks …

Resonant Spectra Of Metal Nanotoroids Of Various Sizes, Huong Quynh Tran

Electrical Engineering Undergraduate Honors Theses

Nowadays, the manipulation of light by using metallic nanostructures has wide applications in photonics, optoelectronics and energy conversion. Along with other universities all over the world, the University of Arkansas is researching on nano-antennas’ design, fabrication and applications. Current research in Dr. El-Shenawee’s Terahertz Imaging and Spectroscopy Computational Electromagnetics Group, has computationally investigated the behaviors of plasmonic nanostructures by using the commercial finite element electromagnetic solver Ansys® HFSS. This work reproduced the previous work of spectral absorption enhancement of infinite and finite arrays of silver and gold nanotoroids with sizes of the inner radii: 13nm – 21nm, while outer radius …

Characterizing Water As Gap Fill For Double Glazing Units, Bright Adu

Masters Theses & Specialist Projects

The use of sunlight has always been a major goal in the design and operation of commercial buildings to minimize electrical consumption of artificial lighting systems. Glazing systems designed to allow optimal visible light transmission also allow significant unwanted direct solar heat gain caused by infrared light. Conversely, glazing systems that are designed to reflect unwanted direct solar heat gain significantly reduce the transmittance of visible light through windows. The goal of this research was to characterize the performance of water as gap-fill for double-glazing units in eliminating the compromises that exist in current glazing systems with respect to light …

Ultrahigh Density Sub-10 Nm Cobalt Nanowire Arrays: Simulation, Fabrication, And Characterization, Yuan Tian

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The simulation, fabrication, and characterization of self-assembled ultrahigh density sub-10nm Co nanowire arrays are presented in this dissertation. The general phase separation nanowire growth simulation was operated based on a modified Ising model. The fabrication process can be summarized as the binary Co-X systems lateral phase separation during physical vapor deposition – the plasma layer deposition with a single alloy Co-X target. The “X” stands for Al or Si. The nanowire fabrication and diameter deduction was achieved by balancing the growth rate and surface diffusivity. For Co-Al binary system, the formed sub-10 nm Co nanowires are of face-centered cubic structure …

Eye Tracking Consumer Purchase Behavior Within Physical And Virtual Environments, David Andrew Stone

All Theses

Understanding how consumers observe and make purchase decisions within a retail context is now both accessible and efficient through the process of eye tracking. Eye tracking package design aesthetics helps us understand and predict what consumers are looking at, and how likely a package might be selected. Typically, this research is conducted in an immersive retail setting where consumers can shop as they would in a normal store-shopping context. A store is stocked with products where a participant in the study shops throughout while wearing an eye tracker to gather data on what their attention fixates on within a given …

Reaction Kinetics Of Rare Earth And Actinide Materials, Brian Jon Jaques

Boise State University Theses and Dissertations

This dissertation presents the effects of atmosphere, time, and energy input (thermal and mechanical) on the kinetics of gas-solid and solid-solid reactions in systems of dysprosium, uranium, oxygen, and nitrogen. Accordingly, Chapter Two presents a novel synthesis technique used to form DyN via a gas-solid reaction between dysprosium and nitrogen. DyN was rapidly formed through a mechanochemical process in a high energy ball mill at ambient temperatures. The progress of the reaction was quantified using in situ temperature and pressure measurements coupled with microscopy and x-ray diffraction. It was found that the rate of the nitridation reaction is controlled by …

Material Coefficient Of Thermal Expansion Investigation For Use In Additive Manufacturing Fused Deposition Modeling For Composite Tooling, Daniel Joseph Miller

Master's Theses

Polymer matrix composites are being used to manufacture light weight, high stiffness aircraft structures. These structures are often manufactured from carbon fiber reinforced epoxy. When these structures are damaged, they must be repaired to restore strength to the component to avoid the cost and logistics of having replacements parts. Occasionally, these repairs require tooling in order to make a quality repair, however, tooling generally has a long lead time. Additive manufacturing could be used to manufacture rapid tooling to create tooling for composite repairs. The issue is that polymer printed tooling has a much higher coefficient of thermal expansion (CTE) …

Zinc Oxide Based Inks For Semiconductor Applications, Shreyas Pathak

Masters Theses

Conventional printing methods are gaining popularity in the manufacturing of electronic components hence being termed as Printed Electronics (PE). IDTechEx has predicted that the total market size of flexible electronics by 2024 would be $70.4 billion. Their report predicts that majority of applications would consume conductive inks. (1)

The main challenge in PE is developing suitable inks for the different printing processes being used to manufacture these electronic components. The experiments in this work mainly involved selecting suitable components for formulating solvent based, semiconductive ZnO inks and then sintering using the NovaCentrix® PulseForge® 1200. ZnO inks were also doped with …

Methods For Growing Retinal Pigment Epithelial Cells: Current Protocols And Future Recommendations, Aaron H. Fronk

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The retinal pigment epithelium (RPE) is a layer of tissue found in the vertebrate eye between Bruch’s membrane and the photoreceptor layer of the neural retina [1]. It is derived from the outer layer of the optic cup [2], possesses an innate immune system [3], and consists of a monolayer of highly pigmented cells that fit together in a tight matrix (fig. 1) [4]–[6]. The monolayer is often compared to a mosaic or cobblestones in its configuration, while the shape of the individual cells is usually described as polygonal/hexagonal, columnar (aligned perpendicular to the underlying membrane), or “epithelioid”. The cells …

Designing A Clarifier To Recover Wastewater Algae Biomass For Production Of Biofuels, Elizabeth Martinez

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The Logan Lagoons, Logan City’s Wastewater Treatment Facility ensures 15 million gallons of wastewater are cleaned and filtered each day. With the implementation of new and stricter wastewater effluent standards, the city of Logan now has to guarantee the phosphorous concentration in the effluent is also reduced. Algal biomass produced and harvested from the lagoons has been proven to affect the way nitrogen and phosphorous are removed, while having the potential to be converted to biofuels. Therefore, implementing a secondary type clarifier in the Logan Lagoons would produce treated water with a reduced phosphorous concentration, and algae feedstock for biofuel …

Cure Kinetics, Morphologies, And Mechanical Properties Of Thermoplastic/Mwcnt Modified Multifunctional Glassy Epoxies Prepared Via Continuous Reaction Methods, Xiaole Cheng

Dissertations

The primary goal of this dissertation is to develop a novel continuous reactor method to prepare partially cured epoxy prepolymers for aerospace prepreg applications with the aim of replacing traditional batch reactors. Compared to batch reactors, the continuous reactor is capable of solubilizing and dispersing a broad range of additives including thermoplastic tougheners, stabilizers, nanoparticles and curatives and advancing epoxy molecular weights and viscosities while reducing energy consumption.

In order to prove this concept, polyethersulfone (PES) modified 4, 4’-diaminodiphenylsulfone (44DDS)/tetraglycidyl-4, 4’-diaminodiphenylmethane (TGDDM) epoxy prepolymers were firstly prepared using both continuous reactor and batch reactor methods. Kinetic studies confirmed the chain …

Erratum: "Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films" (Applied Physics Letters 106:162904 (2015)), Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

There is a typo of the space group. All the Pnmb should be Pbnm (or Pnma). So the Glazer notation should be changed to (a^-a^-c⁺) for Pbnm space group on page 4 of the article. We have also noticed that the thermodynamic analysis of CaTiO₃ thin film is not correct. The films are (001)_PC-oriented or (101)-oriented. Therefore, there is no need to rotate the coordinate system (on page 4 of the article). By applying the thin film boundary condition, i.e., ε₁₁ = ε₂₂ = ε_s, ε …

Origin Of Interfacial Polar Order In Incipient Ferroelectrics, Yijia Gu, Nan Wang, Fei Xue, Long-Qing Chen

Materials Science and Engineering Faculty Research & Creative Works

There are ample experimental evidences indicating that the ferroelastic domain walls of incipient ferroelectrics, such as SrTiO₃ and CaTiO₃, are polar. The emergence of such interfacial polar order at a domain wall is exciting and believed to arise from the coupling between a primary order parameter, such as a strain or an antiferrodistortive (AFD) order parameter, and polarization. There have been several mechanisms proposed to explain the emergence of interfacial polar order, including biquadratic coupling, AFD-antiferroelectric coupling, and flexoelectric coupling. Using CaTiO₃ as an example, we demonstrate, using both asymptotic analytics and numerical calculation, that the …

Kinetics Of Corrosion Of Bn-Zro2-Sic Ceramics In Contact With Si-Killed Steel, Abhishek Kumar, Vivek Thapliyal, David G.C. Robertson, Jeffrey D. Smith

Materials Science and Engineering Faculty Research & Creative Works

The mechanism and kinetics of corrosion of BN-ZrO₂-SiC (MYCROSINT®SO43) by molten Si-killed steel was studied. Isothermal corrosion tests were performed for duration between 2 and 8 h. Refractory and steel composition and morphology changes were investigated. A kinetic model using process simulation software METSIM and thermochemical software FactSage was developed to understand refractory-steel interactions. The corrosion process showed a deviation from parabolic kinetics and was fitted by a combination of linear and parabolic terms. It was determined that corrosion of the BN-ZrO₂-SiC refractory was governed by dissolution of SiC and BN and removal of ZrO_{2 …}

Prediction Of Shear Strength And Ductility Of Cyclically Loaded Reinforced Concrete Columns Using Artificial Intelligence, Nicholas Gordon

UNLV Theses, Dissertations, Professional Papers, and Capstones

The shear strength and deformation capacities of reinforced concrete (RC) columns are governed by a multitude of variables related to material properties of the steel and concrete used in the design and construction of the columns. Predicting performance of RC columns using design variables is a complex, non-linear problem. The prediction of shear strength and ductility for these types of structural members has historically been performed using empirically or semi-empirically derived formulae based on experimental results. The introduction of cyclical lateral loading, such as the forces imposed on a structure during an earthquake, can result in severe degradation of shear …