Materials Science and Engineering Commons^™

Automated Mini-Tubular Ceramic Production, Hunter Brooks, Daniel Freeman, Leo Taranta-Slack

Mechanical Engineering

Researchers at Lawrence Livermore National Laboratory need a way to increase the rate of manufacturing of mini-tubular ceramics to be used in testing particulate air filters. This document outlines our process from researching and writing an initial scope of work all the way to fabricating and testing a final prototype. This journey takes us through the background research, ideation process and selection of a final design. We also detail the desired engineering specifications and our concept selection process. We dedicate a significant portion of this report to discussion of our final design. We delve into how it was manufactured as …

Investigation Of Optical And Structural Properties Of Gesn Heterostructures, Oluwatobi Gabriel Olorunsola

Graduate Theses and Dissertations

Silicon (Si)-based optoelectronics have gained traction due to its primed versatility at developing light-based technologies. Si, however, features indirect bandgap characteristics and suffers relegated optical properties compared to its III-V counterparts. III-Vs have also been hybridized to Si platforms but the resulting technologies are expensive and incompatible with standard complementary-metal-oxide-semiconductor processes. Germanium (Ge), on the other hand, have been engineered to behave like direct bandgap material through tensile strain interventions but are well short of attaining extensive wavelength coverage. To create a competitive material that evades these challenges, transitional amounts of Sn can be incorporated into Ge matrix to form …

Hybrid Two Dimensional Quantum Devices, Joshua Patrick Thompson

Graduate Theses and Dissertations

This thesis describes measurements on hybrid material systems involving two dimensional (2D) materials and phenomena along with the development of a small, hermetically sealed cell. The hermetic cell is designed to assist with analyzing sensitive 2D materials outside of an inert environment. When working with van der Waals materials that are especially sensitive to oxygen or water, it can be difficult to identify usable thin flakes without exposing them to air. To help preserve materials for analysis in air, a capsule was designed that isolates the material in an inert environment. Although the capsule is hermetically sealed, the encapsulated material …

An Investigation Into Energy-Material Properties Interaction In Additive Manufacturing Of Polymers., Pu Han

Electronic Theses and Dissertations

Additive manufacturing (AM), known as three-dimensional (3D) printing, is a fabrication process to build 3D objects layer by layer based on computer aided design (CAD) model or digital 3D model. Fused filament fabrication (FFF) has become a preferred method for additive manufacturing due to its cost-effectiveness and flexibility. However, the parts built using FFF process suffer from lower mechanical strength compared to that fabricated using traditional method and rough surface finish. With this motivation, this dissertation aims to develop and implement a novel in-process laser assisted technique on FFF to heal the microstructure of FFF built objects by enhancing reptation …

Incorporation Of Zinc In Pre-Alloyed Cuin[Zn]S2/Zns Quantum Dots, Jean Carlos Morales Orocu

Graduate Theses and Dissertations

Since the early 2000s heavy-metal-free quantum dots (QDs) such as CuInS2/ZnS have attempted to replace CdSe, their heavy-metal-containing counterparts. CuInS2/ZnS is synthesized in a two-step process that involves the fabrication of CuInS2 (CIS) nanocrystals (NCs) followed by the addition of zinc precursors. Instead of the usual core/shell architecture often exhibited by binary QDs, coating CIS QDs results in alloyed and/or partially alloyed cation-exchange (CATEX) QDs. The effect that zinc has on the properties of CIS NCs was studied by incorporating zinc during the first step of the synthesis. Different In:Cu:Zn ratios were employed in this study, maintaining a constant 4:1 …

Synthesis, Crystal Structure And Ionic Conductivity Of Ruddlesden-Popper Oxide Materials: Effects Of Ionic Radii And Defects On Lithium-Ionic Conductivity., Selorm Joy Fanah

Electronic Theses and Dissertations

Layered perovskite oxides of the Ruddlesden-Popper (RP) type structure can be good lithium-ion conductors for solid electrolyte applications in all-solid-state batteries, due to the large gap separating octahedral layers which can be useful pathways for Li-ion conduction. However, little work has been done on their lithium-ion transport properties in these materials despite their interesting structural properties. This work highlights the synthesis and study of the ionic conductivities in a series of n = 2 and 3 Ruddlesden-Popper oxides, as part of an ongoing investigation in search of alternative solid electrolyte materials. Several different strategies were employed for the enhancement of …

Synthesis And Characterization Of 4,6-Protected Glucosamine Derivatives And Branched Glycoconjugates, Jonathan Bietsch

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are small molecules that self-assemble in appropriate solvents to form three dimensional networks that immobilize the solvent, creating a supramolecular gel. The self-assembly of LMWGs occurs through non-covalent interactions such as hydrogen bonding, aromatic interactions, donor-acceptor interactions, Van der Waals interactions, hydrophobic forces, halogen bonding, etc. Due to self-assembly occurring through reversible non-covalent interactions, supramolecular gels can undergo a gel to solution transformation. Because of this, these materials can be sensitive to external stimuli such as temperature changes, pH changes, and other stimuli that effect non-covalent interactions. This makes the synthesis of LMWG’s an appealing …

Two-Dimensional Black Phosphorus For Terahertz Emission And Near-Field Radiative Heat Transfer, Mahmudul Hasan Doha

Graduate Theses and Dissertations

The main focus of this work is to investigate two potential optical and optoelectronic applications of black phosphorus (BP): the near-field radiative heat transfer in plasmonic heterostructures with graphene and terahertz emission from multi-layer BP photoconductive antennas. When the separation distance between graphene-black phosphorene is much smaller than or comparable to the thermal wavelength at different temperatures, a near-field radiation heat transfer breaks the Planck blackbody limit. The magnitude of the near-field radiation enhancement acutely depends on the gate voltage, doping, and vacuum gap of the graphene and BP pair. The strong near-field radiation heat transfer enhancement of the specific …

Synthesis Of Polyethylene Glycol-Based Hydrogels And Silver/Gold Nanostructures For Biomedical Applications, Isabelle Ishimwe Niyonshuti

Graduate Theses and Dissertations

This work focuses on the synthesis of biocompatible polyethylene glycol (PEG)-based hydrogels, silver nanoparticles (AgNPs), and silver-gold nanocages (Ag-AuNCs) for biomedical applications. The dissertation includes two parts with Part I on the work of PEG-based hydrogel for wound healing applications and Part II on the work of Ag/Au nanostructures for antimicrobial applications. Part I studies PEG-based hydrogel for the delivery of fibroblast growth factors (FGFs) for wound healing applications, aiming to overcome the challenge of designing hydrogels capable of the sustained release of bioactive FGFs. This research develops new biocompatible anionic injectable hydrogel formulations based on Poly (Oligo Ethylene Glycol …

Development Of Lambda Factors For Masonry Design With Lightweight Grout, Rumi Shrestha

All Theses

Reduction in structural mass, improvement in thermal performance, and reduction in shrinkage cracking through internal curing are some of the reasons that lightweight (LW) aggregates have been used in structures and pavements for decades. However, lightweight grout is still not permitted for use in reinforced masonry construction by the TMS 402/602-16 code. In order to realize the benefits of lightweight grout in U.S. reinforced masonry construction, a codified procedure for its use is required which must be informed by experimental testing.

This research is a pilot project directed to characterize the performance of LW grout in comparison to normal weight …

Tensile-Strained Self-Assembly Of Ingaas On Inas(111)A, Kevin D. Vallejo, Trent A. Garrett, Carlos I. Cabrera, Baolai Liang, Kevin A. Grossklaus, Paul J. Simmonds

Materials Science and Engineering Faculty Publications and Presentations

We have determined a reproducible set of growth conditions for the self-assembly of tensile-strained In_1-xGa_xAs quantum dot (QD) nanostructures on (111)A surfaces. During molecular beam epitaxy, In_1-xGa_xAs islands form spontaneously on InAs(111)A when the Ga content x ≥ 50%. We analyze the structure and composition of InGaAs/InAs(111) samples using atomic force microscopy, transmission electron microscopy, and electron energy loss spectroscopy. We demonstrate control over the size and areal density of the islands as a function of In_1-xGa_xAs coverage, In_1-xGa_xAs composition, …

Simulation And Fabrication Of All Oxide-Based Ito/Tio2/Cuo/Au Heterostructure For Solar Cell Applications, Sajal Islam

Graduate Theses/Dissertations

Oxide heterostructures have drawn great attention lately, due to their environment-friendly properties and potential applications in optoelectronic devices. In this work, a simulation study of a heterojunction solar cell was performed with SCAPS (a solar cell simulator) using TiO2 as an n-type and CuO as a p-type layer. The thickness and the dopant-dependent simulations have shown that the solar cell operates at a maximum efficiency of 19.2% when the thickness of the TiO2/CuO layers is chosen 1.4µm/1.2µm compared to the 11.5% efficiency when FTO is replaced with ITO. An indium-doped tin oxide (ITO) vs fluorine-doped tin oxide (FTO) comparison study …

Pulsed Laser Annealing On The Optoelectronic Properties Of Zno Thin Films, Md Abu Zobair

Graduate Theses/Dissertations

ZnO thin films have attracted great attention recently due to their unique electronic and optical properties. However, for proper implementation of ZnO in electronic devices it is necessary to understand the role of native point defects present inside the material as these wide bandgap semiconductors are inherently n-type due to oxygen vacancies. The objective is to control the electronic and optical properties of ZnO thin films through pulsed laser annealing (PLA). Thin films of ZnO have been grown on different substrates using pulsed laser deposition. Then PLA of the films are done by changing laser parameters (energy, frequency, pulse width, …

Dreams Of Molecular Beams: Indium Gallium Arsenide Tensile-Strained Quantum Dots And Advances Towards Dynamic Quantum Dots (Moleculare Radiorum Somnia: Indii Gallii Arsenicus Tensa Quanta Puncta Et Ad Dinamicae Quantae Puntae Progressus), Kevin Daniel Vallejo

Boise State University Theses and Dissertations

Through the operation of a molecular beam epitaxy (MBE) machine, I worked on developing the homoepitaxy of high quality InAs with a (111)A crystallographic orientation. By tuning substrate temperature, we obtained a transition from a 2D island growth mode to step- ow growth. Optimized MBE parameters (substrate temperature = 500 °C, growth rate = 0.12 ML/s and V/III ratio ⩾ 40) lead to growth of extremely smooth InAs(111)A films, free from hillocks and other 3D surface imperfections. We see a correlation between InAs surface smoothness and optical quality, as measured by photoluminescence spectroscopy. This work establishes InAs(111)A as a platform …

Structure And Kinetics Of Twin Boundaries In Shape Memory Alloys, Bibek Jung Karki

Boise State University Theses and Dissertations

Shape memory alloys (SMAs) are functional materials that recover from large strains without permanent deformation. In magnetic shape memory alloys (MSMAs), the reversible deformation is driven either magnetically or mechanically. Two underlying phenomena are responsible for the shape memory effect: (a) a diffusionless, martensitic transformation and (b) twinning in the martensite phase.

In MSMAs, the reversible plastic deformation occurs via twinning in the martensite phase, particularly via the movement of twinning disconnections (TDs) along the twin boundaries (TBs). A geometric algorithm called the classical model (CM) of deformation twinning describes operative twinning modes of a given crystal system. There are …

How To Recognize And Control Interfacial Phenomena That Hinder The Advancement Of Clean Energy Technologies, Corey Michael Efaw

Boise State University Theses and Dissertations

Nuclear energy and electrochemical energy storage, such as batteries, are key parts to the clean energy transition of critical infrastructure. This work aims to define, monitor, and modify interfacial layers that would improve the utility of materials in harsh environments seen in nuclear and energy storage applications. First, the studying of zirconium alloys, which is used as nuclear cladding, was done to better understand the degradation mechanisms within an extreme environment. High-resolution characterization techniques were used to correlate corrosion mechanisms to equivalent circuit models from novel in-pile electrochemical impedance spectroscopy sensors. Advancement in this sensor technology could provide further insight …

Life Cycle Assessment Of Pasture-Based Agrivoltaic Systems: Emissions And Energy Use Of Integrated Rabbit Production, Alexis Pascaris, Robert Handler, Chelsea Schelly, Joshua Pearce

Michigan Tech Publications, Part 1

Agrivoltaic systems, which deliberately maximize the utility of a single parcel of land for both solar photovoltaic (PV) electricity production and agriculture, have been demonstrated as a viable technology that can ameliorate competing land uses and meet growing energy and food demands efficiently. The goal of this study is to assess the environmental impacts of a novel pasture-based agrivoltaic concept: co-farming rabbits and solar PV. A life cycle assessment (LCA) quantified the impacts of 1) the integrated agrivoltaic concept in comparison to conventional practices including 2) separate rabbit farming and PV production and 3) separate rabbit farming and conventional electricity …

Polyvinyl Chloride Gels: Theoretical Modeling Of Their Actuation Mechanism And Characterization Of Their Properties, Zachary Frank

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyvinyl chloride (PVC) gels are an electroactive polymer smart material which has been considered in a variety of actuator applications. Their large deformation, fast response rates, optical transparency, and soft nature has made them a key area of interest in fields ranging from soft robotics to optics. PVC gels are made from PVC mixed with large quantities of plasticizer, such as dibutyl adipate (DBA). When a voltage is applied, the gel experiences an “anodophilic” deformation (in which it moves preferentially towards the anode). This unique characteristic is the result of a charge buildup near the anode surface, which creates electromechanical …

Mechanical Interfacial Locking And Multiscale Modeling Of Reinforced Thermoplastic Composites For Structural Applications, Anmol Kothari

All Dissertations

The ever-growing pressure of reducing the adverse impact of transportation systems on environment has pushed industries towards fuel-efficient and sustainable solutions. While several approaches have been used to improve fuel efficiency, the light-weighting of structural components has proven broadly effective. In this regard, reinforced thermoplastic composites (RTPC), owing to their high recyclability, higher impact strength and fast cycle times, have become competitive candidates at an industrial scale. However, to implement RTPC toward large scale structural applications several challenges pertaining to material design and manufacturing effects need to be addressed. To this end, a computational study is carried out to address …

Investigation And Characterization Of New Optically Stimulated Luminescence (Osl) Dosimetric Materials, Linyu Pan

All Dissertations

Optically stimulated luminescence (OSL) dosimeters have attracted increasing attention due to advantages over TL dosimeters, including no thermal quenching and higher sensitivity. Nevertheless, currently, there are only two commercially available OSL dosimeters, BeO and Al₂O₃:C. An OSL dosimeter requires low effective atomic number (Z_eff < 16), at least one type of recombination center and one type of trap, and UV~blue emission. In this dissertation, motivated by the search of new OSL dosimetric materials, a systematic investigation of alumina (Z_eff = 11.3) and magnesium aluminate spinel (Z_eff = 11.2) based materials was performed in terms of the engineering of the recombination centers and electronic traps. Microstructural characterization was executed by means of X-ray diffraction (XRD) and Raman spectroscopy. Luminescence was characterized under X-ray excitation (radioluminescence; RL) at ambient and …

Bioabsorbable Metal Zinc Differentially Affects Mitochondria In Vascular Endothelial And Smooth Muscle Cells, Olivia R. M. Bagshaw, Fereshteh Moradi, Christopher S. Moffatt, Hillary A. Hettwer, Ping Liang, Jeremy Goldman, Jaroslaw Drelich, Jeffrey A. Stuart

Michigan Tech Publications, Part 1

Zinc is an essential trace element having various structural, catalytic and regulatory interactions with an estimated 3000 proteins. Zinc has drawn recent attention for its use, both as pure metal and alloyed, in arterial stents due to its biodegradability, biocompatibility, and low corrosion rates. Previous studies have demonstrated that zinc metal implants prevent the development of neointimal hyperplasia, which is a common cause of restenosis following coronary intervention. This suppression appears to be smooth muscle cell-specific, as reendothelization of the neointima is not inhibited. To better understand the basis of zinc's differential effects on rat aortic smooth muscle (RASMC) versus …

Single-Walled Carbon Nanotubes Inhibit Trpc4-Mediated Muscarinic Cation Current In Mouse Ileal Myocytes, Lina T. Al Kury, Dimitrios Papandreou, Vasyl V. Hurmach, Dariia O. Dryn, Mariia I. Melnyk, Maxim O. Platonov, Yuriy I. Prylutskyy, Uwe Ritter, Peter Scharff, Alexander V. Zholos

All Works

Single-walled carbon nanotubes (SWCNTs) are characterized by a combination of rather unique physical and chemical properties, which makes them interesting biocompatible nanostruc-tured materials for various applications, including in the biomedical field. SWCNTs are not inert carriers of drug molecules, as they may interact with various biological macromolecules, including ion channels. To investigate the mechanisms of the inhibitory effects of SWCNTs on the muscarinic receptor cation current (mICAT), induced by intracellular GTPγs (200 µM), in isolated mouse ileal myocytes, we have used the patch-clamp method in the whole-cell configuration. Here, we use molecular docking/molecular dynamics simulations and direct patch-clamp recordings of …

Tunable Compressive Mechanical Behavior Of Ice-Templated Materials, Sashanka Akurati

Mechanical & Aerospace Engineering Theses & Dissertations

The inherent hierarchical microstructural organization in natural materials is responsible for their excellent mechanical properties beyond that predicted by the simple rule-of-mixtures. Further exhibit synergy between strength and toughness, otherwise mutually exclusive in brittle materials. Conventional processing methods are unable to replicate hierarchical microstructures in engineering ceramics akin to that observed in natural materials. Ice-templating has emerged as a potential technique to fabricate bioinspired hierarchical materials. This process involves simultaneous unidirectional solidification and phase segregation of aqueous suspensions. Ice-templated porous ceramic materials have received significant attention for overcoming several limitations of conventional ceramic foams currently used in numerous engineering applications. …

Creep Behavior And Deformation Mechanisms Of Spark Plasma Sintered Oxide Ceramics For Aerospace Systems At 1300˚C - 1400˚C, David D. Swanson

Theses and Dissertations

The mechanical behavior of YAG and LuAG was investigated at elevated temperatures. The specific materials investigated in this work include high-purity, polycrystalline YAG, high-purity, polycrystalline LuAG, and two doped variants of YAG: 2at% Yb-doped, polycrystalline YAG and 2at% Er-doped, polycrystalline YAG. Several billets of each material were prepared and processed by means of spark plasma sintering (SPS). Many different sintering parameters were utilized in order to obtain materials with various physical properties and to identify the effects of sintering parameters on the average grain size of the resulting materials. The compressive creep behavior of these materials was investigated at 1300°C …

Energy Efficient Configuration Or Perforated Solar Screens For Residential Desert Buildings, Rasha Arafa

Archived Theses and Dissertations

In hot arid desert environments, the solar radiation passing through windows increases the cooling loads and energy consumption of buildings. Shading of windows can reduce these loads. External perforated wooden solar screens were traditionally used for windowsâ shading. However, there is a lack in understanding their performance in a quantitative manner and unavailability of scientific means that could be used for developing new efficient designs that suit the harsh desert conditions. This thesis investigates the impact of changing screen configurations such as perforation percentage, depth, perforation openings aspect ratio and reflectivity on the energy loads, hence defining the most efficient …

Dechlorination Apparatus For Treating Chloride Salt Wastes: System Evaluation And Scale-Up, Brian J. Riley, Saehwa Chong, Charmayne E. Lonergan

Materials Science and Engineering Faculty Research & Creative Works

This paper describes an apparatus used to remove chlorine from chloride salt-based nuclear wastes from electrochemical reprocessing and/or chloride-based molten salt reactors (MSRs) through dechlorination by reacting the salts with ammonium dihydrogen phosphate (NH₄H₂PO₄ or ADP) at temperatures up to 600 °C to produce NH₄Cl as a byproduct. The benefits of removing the Cl from these salts include ³⁷Cl recovery from Cl-based MSR salts, formation of UCl₃ from the NH₄Cl, as well as removal of Cl from the salts and conversion of the salt cations to oxides to allow …

Wear Property Of Machined Ultra High Molecular Weight Polyethylene (Uhmwpe) Acetabular Liner Product With Cnc Milling, W D. Lestari, A T. Danaryanto, A Nugroho, R Ismail, J Jamari, A P. Bayuseno

Journal of Mechanical Engineering Science and Technology (JMEST)

UHMWPE has been used as a cushion in artificial hip joint for the last decades. The reliability of the components of a hip joint implant can be achieved by understanding their wear behavior. This study observed the tribological performance of the UHMWPE acetabular liner manufactured with a CNC milling machine on the femoral head made of SS 316L. Materials commonly used for tribo pairs in hip joint replacement. The wear tests were performed on a hip joint simulator in dry condition. The wear test is carried out by applying a constant load of 800N. Before and after the wear test, …

Characterization Of Bacterial Nanocellulose - Graphite Nanoplatelets Composite Films, Bili Darnanto Susilo, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Bacterial cellulose (BC) was synthesized from pineapple peel extract media with addition of fermentation agent bacteria Acetobacter xylinum. BC was disintegrated from the pellicle into bacterial nanocellulose (BNC) by using a high-pressure homogenizer (hph) machine, which has a three-dimensional woven nanofibrous network. The synthesis of composite films started when BNC, graphite nanoplatelets, and cetyltrimethylammonium bromide (CTAB) were homogenized using an ultrasonic homogenizer then baked on a glass mold at a temperature of 80 degrees Celcius for 14h. A scanning electron microscope (SEM) was used to analyze its morphology. X-Ray diffraction spectra were used to analyze the composite films structure. The …

Design Of Shielded Metal Arc Welding Parameters For Optimum Tensile Strength Using Taguchi Method, Moh. Dedy Setiawan, Yanuar Rohmat A. P. Pradana, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

Shielded Metal Arc Welding (SMAW), an arc welding process, is widely used in applications. In practice, SMAW is widely applied to the welding process on hollow square pipe. Performance expected from this welding is the tensile strength of weld joint. The tensile strength is influenced by parameters process which have possibility for an optimization process to become ‘robust’. Robust is a design which less sensitive to the effect of uncertain quantities or noise factors. Taguchi method is the most efficient optimization method which accommodates the noise factors effect and requires less experiment. This study is focusing on optimizing the welding …

Comparative Studies On Combustion Characteristics Of Blended Crude Jatropha Oil With Magnetic Liquid Catalyst And Dex Under Normal Gravity Condition, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

A comparative study on the combustion characteristics of a single droplet fueled by DEX, crude jatropha oil (CJO), and a mixture of CJO with a magnetic liquid catalyst of rhodium trisulfate has been carried out under normal gravity conditions. The high viscosity of crude jatropha oil makes it difficult to burn under normal conditions (room temperature and atmospheric pressure), therefore the addition of a magnetic liquid catalyst rhodium trisulfate is needed to improve the properties of crude jatropha oil. As a catalyst, rhodium trisulfate has the potential to improve combustion performance while improving the physical properties of crude jatropha oil …