Materials Science and Engineering Commons^™

Fluid Modeling And Analysis Of A Mash Tl-6 Vehicle Model, Elisa Vasquez

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

The objective of this research project was to replicate the dynamic behavior of a truck-tank trailer combination vehicle using representative dimensions, properties, and inertias of the trailer/fluid ballast combination. A literature review was completed describing techniques for modeling fluids and fluid-container interactions using finite element analysis. Various fluid modeling techniques were identified, and parameters associated with those models were archived. Next, researchers utilized the tank geometry of the elliptical straight-frame 5949 trailer produced by LBT Inc. to generate a finite element mesh using finite element analysis preprocessors HyperMesh and LS PrePost. Material properties were taken from reference guides, research papers, …

Manipulating Air-Gap Electrospinning To Create Aligned Polymer Nanofiber-Wrapped Glass Microfibers For Cortical Bone Tissue Engineering, Houston R. Linder, Austin A. Glass, Delbert E. Day, Scott A. Sell

Materials Science and Engineering Faculty Research & Creative Works

Osteons are the repeating unit throughout cortical bone, consisting of canals filled with blood and nerve vessels surrounded by concentric lamella of hydroxyapatite-containing collagen fibers, providing mechanical strength. Creating a biodegradable scaffold that mimics the osteon structure is crucial for optimizing cellular infiltration and ultimately the replacement of the scaffold with native cortical bone. In this study, a modified air-gap electrospinning setup was exploited to continuously wrap highly aligned polycaprolactone polymer nanofibers around individual 1393 bioactive glass microfibers, resulting in a synthetic structure similar to osteons. By varying the parameters of the device, scaffolds with polymer fibers wrapped at angles …

Defect Evolution In High-Temperature Irradiated Nuclear Graphite, Steve Johns

Boise State University Theses and Dissertations

Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of …

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …

The Effect Of Compaction Temperature And Pressure On Mechanical Properties Of 3d Printed Short Glass Fiber Composites, Pushpashree Jain Ajith Kumar Jain

Mechanical & Aerospace Engineering Theses & Dissertations

Among many thermoplastics that are used in engineering, polyamide 6 (nylon 6) is an extremely versatile engineering thermoplastic. Nylon filled with glass fibers has higher mechanical strength and high wear resistance than general purpose nylon. 3D printed composites, based on fused filament modeling, typically suffer from poor bead-to-bead bonding and relatively high void content, limiting their mechanical properties

This thesis explores the effect of compaction pressure and temperature on improving the mechanical properties of 3D printed composites. Engineering moduli in the printing and transverse to printing direction, as well as ultimate strength were measured using the tensile testing with Digital …

Synthesis, Characterization, Spectroscopic, And Mesomorphic Studies Of New Schiff Base Ligands And Titanium, Cobalt, Nickel And Copper Metal Centers, Raj K. Gurung

Chemistry & Biochemistry Theses & Dissertations

Transition metal complexes with Schiff base ligands offer a wide application in the field of development of catalysis and material. The straightforward synthesis allowed the structural modification and helped to optimize in various application of such complexes. Titanium-containing complexes have been reported to be important for their catalytic and material applications through the coordination of a tetradentate Schiff base ligand, viz. N, N’-ethylene bis(salicylideneiminate) dianion (salen). Studies reporting the characterization of achiral titanium(IV) salen complexes are scarce due to their intricate nature. Such complexes would be comparatively less expensive and easier to prepare synthetically and thus could represent an …

Developments Of Machine Learning Potentials For Atomistic Simulations, Howard Yanxon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Atomistic modeling methods such as molecular dynamics play important roles in investigating time-dependent physical and chemical processes at the microscopic level. In the simulations, energy and forces, sometimes including stress tensor, need to be recalculated iteratively as the atomic configuration evolves. Consequently, atomistic simulations crucially depend on the accuracy of the underlying potential energy surface. Modern quantum mechanical modeling based on density functional theory can consistently generate an accurate description of the potential energy surface. In most cases, molecular dynamics simulations based on density functional theory suffer from highly demanding computational costs. On the other hand, atomistic simulations based on …

Mechanical Characterization And Wear Behavior Of Aerospace Alloy Aa2124 And Micro B4c Reinforced Metal Composites, Fazil N, V Venkataraman, Madeva Nagaral

Journal of Metals, Materials and Minerals

In the present investigation, the mechanical and wear properties of aerospace alloy AA2124-9wt%of B4C composites were displayed. The composites containing 9wt% of micro boron carbidein AA2124 alloy were synthesized by liquid metallurgy method through stir casting. For the composites, reinforcement particles were preheated to a temperature of 400°Cand afterward added in ventures of two stages into the vortex of liquid AA2124 alloy compound to improve the wettability anddispersion. Microstructural examination was carried out by SEM and elemental investigation was finished by EDS. Mechanical and wear properties of as cast AA2124 alloy and AA214-9wt% of B4C composites were evaluated as per …

Effect Of Amorphous Rice Husk Silica Additionon The Structure Of Asphalt Composite, Simon Sembiring, Agus Riyanto, Rudy Situmeang, Zipora Sembiring, Nita Susanti, Iqbal Firdaus

Journal of Metals, Materials and Minerals

In this study, modified asphalt composites were produced by adding silica extracted from rice husk.The mass ratios of asphalt to silica are 1:0, 1:1.6, 1:1.8, and 1:2 and calcined at the temperature of 150C for 6 h.The structural and microstructural characteristics of asphalt composites were examinedby x-ray diffraction (XRD),Scanning Electron Microscopy/Energy Dispersive x-ray (SEM-EDX) Spectroscopy and Differential Thermal Analysis (DTA-TGA),respectively. The XRDstudy revealed that the major phases were carbon and amorphous silica. The surface morphology of asphalt without silica addition presents a cluster of larger size than the cluster of asphalt with an addition of silica. The addition of silica …

Additive Manufacturing Of Graphene-Based Devices For Flexible Hybrid Electronics, Twinkle Pandhi

Boise State University Theses and Dissertations

In this work, I investigate and enhance the fundamental sensing properties of printed electronic nanomaterials (e.g., graphene) in real-world environments while decreasing weight, cost, and power consumption. The dissertation addresses this issue with the following foci in mind: (1) developing a straightforward and repeatable process to synthesize graphene ink which is also compatible with Inkjet-printing (IJP) and Aerosol Jet printing (AJP). (2) Tuning additive manufacturing printing (IJP and AJP) parameters to establish a repeatable manufacturing process and print high performing (graphene-based) electrodes and interconnects, compatible with the underlying substrate. (3) Investigate power dissipation and electrical breakdown in AJP printed graphene …

Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson

Boise State University Theses and Dissertations

The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end …

Modeling And Analysis For Unit Cell Size, Material Anisotropy And Material Imperfection Effects Of Cellular Structures Fabricated By Powder Bed Fusion Additive Manufacturing., Yan Wu

Electronic Theses and Dissertations

Cellular structures are networks of interconnected struts or walls with porosities and are widely found in many natural load-bearing structures such as plants and bones. Cellular structures offer unique functional characteristics such as high stiffness to weight ratio, tailorable heat transfer coefficient, and enhanced mechanical energy absorption, which makes them highly attractive in various engineering disciplines such as biomedical implants, electrodes, heat exchangers, and lightweight structures. There exists an abundance of literatures that have investigated various mechanical properties of various cellular structures such as Poisson’s ratio, elastic modulus, ultimate strength, yield strength, and failure characteristics. Based on the classic cellular …

Ultrafast Spin-Currents And Charge Conversion At 3d-5d Interfaces Probed By Time-Domain Terahertz Spectroscopy, T. H. Dang, J. Hawecker, E. Rongione, G. Baez Flores, D. Q. To, J. C. Rojas-Sanchez, H. Nong, J. Mangeney, J. Tignon, F. Godel, S. Collin, P. Seneor, M. Bibes, A. Fert, M. Anane, J. M. George, L. Vila, M. Cosset-Cheneau, D. Dolfi, R. Lebrun, P. Bortolotti, Kirill Belashchenko, S. Dhillon, H. Jaffrès

Kirill Belashchenko Publications

Spintronic structures are extensively investigated for their spin-orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-Transition metal interfaces due to their inverse spin-Hall effect properties. In particular, the intrinsic inverse spin-Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques-ultrafast THz time-domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping …

Effects Of Ca Doping On Structural And Optical Properties Of Pzt Nanopowders, K. H. Omran, M. Mostafa, M. S. Abd El-Sadek, O. M. Hemeda, R. Ubic

Materials Science and Engineering Faculty Publications and Presentations

The influence of the addition of calcium ions (Ca²⁺) in the Pb_(1-x)Ca_xZr_0.52Ti_0.48O₃ system (PCZT) for x = 0.05, 0.10, 0.15, 0.20, and 0.25 on the structural and optical properties was systematically studied. The compositions were synthesized through a polymerized-complex approach based on the Pechini polymeric precursor route. The solubility limit of calcium ions within the PCZT lattice is in between x = 0.10 and x = 0.15, at which a CaTiO₃ secondary phase is detected. The Goldschmidt tolerance factors, modified tolerance factors, and the effective vacancy sizes were …

Exploring The Variability In The Gray Scale Imaging Process Of Asphalt Samples, David Oluwawade Olatunji

Civil Engineering Undergraduate Honors Theses

Gray scale image analysis is a powerful tool for testing asphalt concrete materials. From material composition to surface properties, gray scale analysis has shown evidence as a non-invasive way to obtain information from asphalt samples. Casillas et al. used a gray scale analysis to measure the Representative Volume Element of three asphalt sample geometries to understand the minimum size at which an asphalt sample is representative of a larger homogeneous mixture [1]. While the gray scale analysis used in this experiment yielded results, there were unknown factors in the image capturing process. Particularly, not much was known about the effect …

Spatially Directed Functionalization By Co-Electropolymerization Of Two 3,4-Ethylenedioxythiophene Derivatives On Microelectrodes Within An Array, Benjamin J. Jones, Carol Korzeniewski, Jefferson H. Franco, Shelley D. Minteer, Ingrid Fritsch

Chemistry & Biochemistry Faculty Publications and Presentations

Electrodeposited conductive copolymer films with predictable relative properties (quantities of functional groups for further modification and capacitance) are of interest in sensors, organic electronic materials and energy applications. Potentiodynamic copolymerization of films in aqueous solutions of two different thiophene derivatives, (2,3-dihydrothieno[3,4-b]dioxin-2-yl) methanol (1) and 4-((2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)-methoxy)-4-oxobutanoic acid (2), containing 0.02 M total monomer (0, 25, 34, 50, 66, 75, 100 mol% 2), 0.05 M sodium dodecyl sulfate, and 0.1 M LiClO4, on gold microelectrodes in an array was investigated. Decreasing monomer deposited (m) from 0 to 100 mol% 2 is attributed to a decreasing pH that inhibits electropolymerization. Molar ratios of …

Dyeing Properties And Color Fastness Of Eri Silk Yarn Dyed With Soaked Red Kidneybean Water, Piyaporn Kampeerapappun, Kritsana Wongwandee, Siriluk Janon

Journal of Metals, Materials and Minerals

The purpose of this research was to study the dyeing of eri silk yarn using soaked red bean water. The optimal condition for preparing dye solutions was a ratio of 1:5 of dried red bean to water and dyeing at 100°C for 45 min. The dyeing process was conducted with and without mordants, using three different mordanting methods; pre-mordanting, meta-mordanting, and post-mordanting. The effects on silk analyzed are color fastness to washing, wet and dry rubbing, acid and alkali perspiration, and color characteristics on CIEL*a*b* color coordinates.Without mordants, the dyed silk yarn gave a rosy brown color. Each mordant caused …

Effect Of Variations In The Composition And Size Of Red Sand Grains On The Quality Of K-225 Concrete, Mukti Hamjah Harahap, Aulia E. Putri

Journal of Metals, Materials and Minerals

The effect of variations in the composition and size of red sand grains on the solid quality made in the form of a 15×15×15 cm cubes were investigated. By implementing the standard of SNI K-225 which is a mixture of 1:1.9:2.8 with FAS 0.6 and the composition of red sand consisting of 0, 2, 4, 5,and 6.5% of the weight of fine aggregate and variations in the size of red sand grains of 80, 100, and 120 mesh, the concrete was being treated in a water bath for 28 days. It was tested by the method of water absorption, compressive …

High-Temperature Optoelectronic Device Characterization And Integration Towards Optical Isolation For High-Density Power Modules, Syam Madhusoodhanan

Graduate Theses and Dissertations

Power modules based on wide bandgap (WBG) materials enhance reliability and considerably reduce cooling requirements that lead to a significant reduction in total system cost and weight. Although these innovative properties lead power modules to higher power density, some concerns still need to be addressed to take full advantage of WBG-based modules. For example, the use of bulky transformers as a galvanic isolation system to float the high voltage gate driver limits further size reduction of the high-temperature power modules. Bulky transformers can be replaced by integrating high-temperature optocouplers to scale down power modules further and achieve disrupting performance in …

An Overview Of Ceramic Molds For Investment Casting Of Nickel Superalloys, Janos E. Kanyo, Stefan Schafföner, R. Sharon Uwanyuze, Kaitlynn S. Leary

Materials Science and Engineering Faculty Research & Creative Works

Accelerating advancements in technological systems have demonstrated a need for alloys with drastically improved thermomechanical and chemical properties, called superalloys. Ceramic molds are typically used in near-net shape investment casting processes of superalloy components due to their chemical inertness and high-temperature capabilities. Ceramic molds, however, often suffer from shortcomings in vital properties including flexural strength, thermal shock resistance, permeability, dimensional stability, corrosion resistance, and leachability, which have restricted their ability to adequately process modern alloy castings. This study analyses these limitations and illustrates how to address them, particularly regarding ceramic mold and slurry design, processing of shells and cores, material …