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Item 3-D Graphical Area Mapping Bilinear Interactive Technology [3-D GAMBIT](Alfred University. Inamori School of Engineering., 2017-09) Itzhakov, Ariel A.; Lee, Seong-Jin; Rosiczkowski, Joseph; Leigh, WallaceThe main goal for this thesis project is to develop a 3-D image scanner that will be used as part of a larger effort in robotics and obstacle detection and avoidance. The scanner developed will be added to another robotics project being done by Dr. Seong-Jin Lee, Wanrui He, and Andres Garcia at Alfred University. Known as the Bubblebot, this robot is currently being designed to expand and contract to maneuver through different size spaces. The Bubblebot will use the scanner designed and built during this thesis project to map the area and determine the optimal size it needs to be to navigate through its environment. When researching previous 3-D mapping methods, i.e. RGB-D and Simultaneous Localization and Mapping (SLAM), three main flaws in many of the current techniques were determined and corrected. First was the inability to determine the distances of the objects in the scanner's range. Second was the size of the equipment needed for the 3-D scanner. Finally, the third was the large processing power needed to run the 3-D image generator program. To correct these problems as best as possible, simple parts and programs were used including a web cam and bilinear line laser along with the Arduino and Processing programs. During the testing stage, the 3-D scanner was completed and mounted onto a sample robot for testing. With the use of a Raspberry Pi model 3B the robot was programmed to map its environment, identify any obstacles in its path, and avoid them during navigation without the need of any human interaction. Overall the result of this project looked positive and when tested successfully worked. The final step for this 3-D scanner will be integrating it to the Bubblebot upon its completion.Item 3D Printed Ceramics After ISS Spaceflight(Inamori School of Engineering, Alfred University., 2022-09) Bailey, Alexander; Wang, Xingwu; Clare, Alexis; Rosiczkowski, JosephThis work characterizes 3D printed ceramics after space flight aboard the ISS. Along with water immersion and mercury immersion testing, visual data was collected via SEM, AFM and TEM evaluation. Bulk resistivity was measured via two-point contact probe methods. Cumulative radiation dosage was approximated with data collected from NOAA's GOES system. The SEM micrographs did not provide data for bubbles in the glassy phases of the material, but the TEM data showed bubbles in the polycrystalline structure of the control and experimental batch A specimens. The bulk resistivity testing ultimately revealed that the experimental specimens became less thermally dependent when temperatures varied from 50 °C to 75 °C. This work indicates the need for longer space experiment and radiation exposure durations. Of the two sample batches evaluated, the batch A variant shows promise for future study.Item 3D Printing Silver- and Copper-Doped Hydroxyapatite Scaffolds for Use as Bone Substitute(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2022-08) Wallisch, Abigail; Keenan, Timothy; Ding, Junjun; Sundaram, S.K.With the objective of 3D printing antibacterial bone scaffolds in mind, silver- and copper-doped hydroxyapatite was synthesized through precipitation. The formulation was created with the intention of ten percent dopant substitution in calcium sites. The resulting solid was then milled into to a powder. Phase identification through X-ray diffraction verified the structural composition was hydroxyapatite. Elemental analysis through X-ray fluorescence (XRF) showed the silver-doped powders had 0.3 atomic percent dopant and the copper-doped powders had 1.1 atomic percent dopant, both below the expected goal of 2.7 atomic percent. Secondary electron imaging through scanning electron microscopy provided visualization of porous particles with a wide particle size distribution. Energy dispersive spectroscopy (EDS) showed little evidence of any detectable dopant concentration in the powders, which was consistent with the low dopant content detected through XRF. Particle size analysis through dynamicc light scattering revealed mean particle sizes of 2.2 μm and 1.2 μm for the silver-doped and copper-doped hydroxyapatite samples, respectively. Surface area analysis through the Brunauer-Emmett-Teller method measurements reported 80.0 ± 0.2 m²/g for the silver-doped sample and 342.0 ± 0.6 m²/g for the copper-doped sample. The powders were sent to Lithoz America for slurry preparation using their proprietary recipes. The porosity and agglomeration of the powders proved to be an obstacle for achieving a slurry with an appropriate solids loading for Lithoz's lithography-based ceramic manufacturing system. After a series of failed attempts, it was discovered that the powders' agglomerates were absorbing the resin. As a result, the effective solids loading of the slurries widely strayed from the measured solids loading. With this added knowledge, both powders were successfully prepared into printable slurries. Both slurries were printed into nine scaffolds, all 10 mm in length, 10 mm in width, and 5 mm in height. Both compositions underwent curing complications during the run. Scaffolds were then cleaned, with difficulty, using the Lithoz proprietary solvent, LithoSol 20. They underwent three firing cycles: preconditioning, debinding, and sintering. The preconditioning cycle was held at a maximum temperature of 120°C for 72 hours, the debinding cycle was held above 600°C for 9 hours with a maximum instantaneous temperature of 1000°C, and the sintering cycle was held at a maximum temperature of 1100°C for 2 hours. After sintering, the scaffolds were considerably smaller in size. The shrinkage of the silver-doped scaffolds was ~35% in the XY directions and ~30% in the Z direction. The shrinkage of the copper-doped scaffolds was ~40% in the XY direction and ~35% in the Z direction. The Archimedes density was calculated to be 2.01 g/m³ for the silver-doped scaffolds and 2.20 g/m³ for the copper-doped scaffolds, both densities higher than that of human bone. EDS data indicated a lack of homogeneity within the silver-doped scaffolds and phase separation in the copper-doped scaffolds. The silver-doped scaffolds consisted of regions that ranged in concentration from undetectable amounts of silver to 6.25 atomic percent silver. Conversely, the copper-doped scaffolds had copper-rich deposits with 56.26 atomic percent copper and a region with an undetectable copper concentration. Scaffolds were tested for antibacterial behavior through exposure to Staphylococcus aureus, a gram positive species of bacteria, and Escherichia coli, a gram negative species of bacteria. These tests showed little evidence of antibacterial activity. Each inhibition zone for the twelve tested scaffolds was 0mm. It was concluded that this was a result of multiple factors: non-homogeneity, agar levels in the petri dish, and low dopant concentrations. In order to achieve a viable antibacterial bone substitute customizable to a patient's needs, a lower density, a higher degree of homogeneity, and a higher dopant concentration must be achieved in 3D-printed parts. Additionally, achieving a controllable and adjustable density is necessary for meeting the needs of a variety of patients.Item Additive Manufacturing of Hybrid Composites for Flexible Electronic Application(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2023-08) Gao, Yuqi; Ding, Junjun; Wu, Yiquan; Wren, Anthony; Tidrow, StevenMaterial extrusion 3D printing is capable of fabricating complex macrostructures and designing microstructures for next-generation flexible electronics. Thick electrodes are promising to increase the mass loading of active materials in supercapacitors, but the 3D geometries and microstructures in thick electrodes still hinder the development with high electron and ion exchange rate and accessible active sites. The scaffold 3D electrodes of reduced graphene oxide:manganese oxide/carbon nanotube (rGO:MnOx/CNT) with highly-ordered microstructure were manufactured by material extrusion 3D printing, freeze-drying, and thermal treatment. The increasing amount of MnOx/CNT composites improved the areal capacitance. And the rate capability remained stable at different thicknesses. A 2 mm thick rGO:MnOx/CNT (weight ratio 5:3) electrode exhibited an excellent area capacitance contributed by the highly ordered rGO networks. Fiber-shaped supercapacitors are attractive as an energy storage unit due to their excellent flexibility. However, fabricating robust fibers with large yields remained a challenge. The present study fabricated the core-sheath fibers through coaxial extrusion printing. Carboxymethylcellulose sodium salt (CMC) slurry with controlled rheological properties was extruded from the outer channel, while GO slurry was extruded from the inner channel simultaneously. The followed freeze-drying process protected GO sheets from agglomeration, providing more efficient chemical reduction. After reduction, rGO sheets were separated and expanded to fill in the CMC sheath, which eliminated the delamination between the CMC sheath and rGO core. Apart from the 1D core-sheath fiber electrode, 3D printed electrode with core-sheath structure provided a solution for the development of thick supercapacitors. Specifically, 3D thick rGO/CNT-rGO/CNT/MnO@CNT (rGC-rGCMC) electrodes with controlled lattice architectures, core-sheath structure, and hierarchical porosity were prepared. The electrodes with different volume ratios of core to sheath, including 100%-0%, 0%-100%, 20%-80%, 30%-70%, 40%-60%, and 50%-50%, were investigated to explore the influences of core-sheath structure on thick electrodes. All capacitance decays from core-sheath electrodes (20%-80%, 30%-70%, 40%-60%, and 50%-50%) were smaller than rGCMC (0%-100%) electrodes, indicating the improved rate capability from the core-sheath structure. Compared 30%-70% core-sheath electrodes with electrodes made of homogenous 30% rGC and 70% rGCMC mixture (30%+70%), lower capacitance (382.27 mF cm^-2 and 25.66 F g^-1 at 0.5 mA cm^-2) of 30%+70% mixture electrode without core-sheath structure suggested less efficiency to harvest electrons from the redox reactions. Electrochemical impedance spectroscopy (EIS) data further supported and explained the resistances of thick electrodes with different volume ratios.Item Additive Manufacturing of YSZ and Lithium Silicate Electroceramics for Energy Generation and Storage(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2021-04) Zaengle, John T. H. C.; Sundaram, S.K.; Keenan, Timothy; Ding, JunjunAdditive manufacturing (AM) of electroceramics is of interest because electroceramics are an excellent fit for solid oxide electrolytes. Faster material testing through the use of rapid prototyping made available through advances in additive manufacturing is now available. This investigation summarizes work on two materials of interest for energy generation and storage applications, fully stabilized 8 mol% yttria-stabilized zirconia (YSZ) and lithium silicate powders printed with a Lithoz CeraFab 8500 lithography-based ceramic slurry printer. This thesis focuses on variations in base powder, binder system, solids loading, heating profile, layer thickness, and layer orientation. Final part density, porosity, grain size, resistance, conductivity, activation energy, and crystal structure were measured to determine both the viability of 3D-printing and the effects the layers might have on microstructure. Tosoh TZ-8YS powders mixed with Lithoz MS13B binder at a solid loading of 46.5 vol % sintered at 1450°C resulted in highly dense uniform parts with no noticeable variations in bulk resistance, conductivity, or activation energy due to layering. Lithium silicate powders mixed with Lithoz MS13B binder at a solid loading of 51 vol % sintered at 800°C resulted in dense parts with surface abnormalities and no noticeable variations in bulk resistance, conductivity, or activation because of layering. The results show that base powder, binder system, solids loading, and layer thickness are important for 3D-printing. Slurry viscosity with a solid loading between 40 and 50 % is controlled by powder, solids loading, and binder. Microstructure and successful densification of samples depend on powder quality, heating profile, layer orientation, and binder system. In addition, the layering does not have a direct impact on the electrical properties of 3D-printed parts.Item Adhesion Studies with Ultra-Thin Glass(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2022-02) Fekety, Curtis; LaCourse, William; Sundaram, S.K.; Clare, AlexisA phenomenon was observed during work producing "ultra-thin glass" (<150μ thickness) where samples folded onto themselves displayed strong adhesion and served as a simple method to analyze contaminants in the process and packaging of resulting ware. Subsequent Contact Angle, Wedge Test, and T-Peel studies were performed to understand the baseline of Surface Free Energy (SFE) for this direct bonding and attempts were made to refresh aged and packaged samples through various cleaning steps to produce a similar effect. When results showed SFE change was minimal between aged, cleaned, and fresh glass and no treatments enabled similar direct bonding to fresh samples, 90° and 180° Peel Test with adhesive tapes and films were used as a surrogate to rank the effectiveness of attempted cleaning procedures. Such tests yielded widely ranging values inherent to known issues with peel testing, but provided useful data to calculate true adhesion values of just 2 - 2.5 N/m, which were 1 to 3 orders of magnitude less than the experimental values due to work absorbed by elastic/plastic effects when peeling the polymer adherend. Highly flexible glass samples do not experience plastic deformation, so studying direct bonded ultra-thin glass provides a unique perspective on adhesion studies by excluding plastic effects. It was also demonstrated that although the direct bonded samples had even lower peel strengths after initial separation, the bond strength was higher than strong tapes and even epoxy prior to edge-crack formation, showing the usefulness of direct bonding in optical materials and potential for future development.Item Analysis of Drag Reduction Using Aerodynamic Devices on Commercial Buses by Computational Fluid Dynamic Simulation(Kazuo Inamori School of Engineering at Alfred University., 2015-09) Brown, Rachel; Lee, Seong-JinA large percentage of the usable fuel employed in a commercial bus is utilized to overcome the aerodynamic drag at highway speeds and therefore if reduced could produce a large reduction in the total fuel consumption of the vehicle and reduce the negative environmental effects. MCI's D4505 coach bus was modeled in this study and airvanes, drag reduction devices, were employed on the model bus to reduce the drag coefficient of the bus. Each airvane, attached to edges of the leeward face of the bus, was optimized by a parameter study were each individual dimension of the device was tested to determine the optimal design. The airflow surrounding the bus models with and without the airvanes attached were modeled using a computational fluid dynamics software. In this software different turbulence models and meshes were employed to observe the effect of these changes on the predicted airflow and optimization of the aerodynamic devices. Two separate sets of simulations were run on each dimension tested. The first simulation utilized a polyhedral mesh with the Realizable k-ε turbulence model, while the second set of simulations used a CutCell mesh and the Shear Stress Transport k-ω turbulence model. It was found that to reach a maximum reduction of the drag coefficient of the bus airvanes were placed on all edges of the leeward face and optimized for the specific placement on the bus. A drag coefficient of 0.54351 was produced which was a reduction of 12.37% for the polyhedral RKE model while the CutCell SST model produced a drag coefficient of 0.54021 a reduction of 14.55%. This reduction in the drag coefficient lead to a maximum reduction of 1.5% in the fuel consumption, which if applied to all commercial buses would have a significant effect on the total national fuel consumption and a positive impact on the environment.Item Analysis of Earthquake Impact on Solar Houses via Finite Element Method - ABAQUS(Alfred University. Inamori School of Engineering., 2017-09) Ding, Ding; Wang, Xingwu; Leigh, Wallace; Rosiczkowski, JosephSolar PV systems may be considered in areas affected by earthquakes. However, such solar systems should be designed to resist earthquakes. The impacts on solar systems will be studied as the first step. Earthquake generates the most extreme vibration as a natural disaster. An increasing number of active solar PV systems are being installed on solar houses located in earthquake zones. The impact of earthquakes on these solar homes needs to be assessed as these facilities are relatively new. With an earthquake and sunlight occurring simultaneously, the solar PV modules may still generate electricity. Yet, there is concern that the wires may short circuit due to wires crossing path, which creates a fire hazard. For solar house applications, there is no single code/regulation/standard dealing with earthquake safety in California. Some houses with smaller roof slopes are having solar panels rest on the roofs, thereby using frictional forces to restrain the solar harvesting equipment. The purpose of this study is to evaluate the possibilities of damage due to earthquakes. According to the earthquake analysis, earthquakes might cause two events in sequence: one, exposing the bare metal wires, and two, shorting two leads. With flammable materials nearby, a fire may be started due to the two situations mentioned up above. Researchers normally invest in a significant amount of time and money for quality verification of products; the most common structural analysis is used in shocking and striking experiments. In order to improve safety assurance, manufactures expect to make more environmental-friendly and safer products in a short amount of time. With the purpose of enhancing shock resistance and seismic resistance, traditional methods are used to conduct physical experiment for finding solutions. Thus, a process of design, manufacture, tests and re-design are required. This procedure will waste a significant amount of man power and material resources. On the other hand, due to the limitation of the equipment's size, quality and price, physical experiment is beset with difficulties. Taking advantage of using FEA simulation tests can make up for the deficiency of this challenge. FEA software could finish simulating and getting results from the computer model before the sample was created. This will give researchers an advanced knowledge in impact resistance and antiknock characteristics. This will help cut down the research period, maximize use of research funding, and heighten safety and practicability. Utilizing the FEA software, this thesis analyzes and simulates the potential damage due to material failure or bare wire metals suffering from seismic acceleration. In this study, a dynamic earthquake simulation was conducted on solar houses. Finite Element Analysis was performed to obtain the variation of stress magnitude at critical locations.Item Aqueous Processing of Alumina and Phase Behavior of Polymeric Additives(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 1999-12) Sundlof, Brian; Carty, WilliamThe goal of this research was to produce ceramic alumina microstructures with controlled porosity attained through the exploitation of polymeric phase separation. In order to accomplish this goal, a fundamental understanding of the aqueous colloidal behavior and sintering of alumina were required. The ability to manipulate the polymeric phase separation process was necessary in order to tailor porosity. For this reason, background information regarding the phase separation process and the parameters associated with its thermodynamic and kinetic properties were essential. The dispersion of aqueous suspensions of two a-aluminas (APA-0.5 and A-16 S.G.), were investigated. APA-0.5 was a high purity powder, and A-16 S.G. had MgO added as a sintering aid and contained relatively high levels of other impurities, most notably Na2O. The APA-0.5 was used as a standard alumina, while the A-16 S.G. represented a common industrial powder. Acids (HCl and H2SO4) and bases (NaOH and NH4OH) were used to adjust suspension pH. HCl was the only electrostatic dispersant found to substantially alter suspension viscosity. The z -potential and critical coagulation concentration (CCC) of electrostatically dispersed with HCl suspensions were measured. A correlation was found between the CCC and the inability of H2SO4, NaOH, and NH4OH to disperse alumina. The inorganic anionic polyelectrolytes examined included sodium silicate, sodium hexa-metaphosphate, and sodium carbonate. Comparisons were made between plots of the different polyelectrolytes (viscosity as a function of dispersant level), as well as between the two aluminas. Rheological phenomena correlated with z -potential measurements, the dissociation behavior of the polyelectrolytes, and the powder surface chemistry. The organic anionic polyelectrolytes examined include the sodium and ammonium salts of poly(methacrylic acid) and poly(acrylic acid), and neutralized citric acid. Comparisons were made between dispersants (viscosity as a function of dispersant level), including effectiveness and general rheological trends. Rheological phenomena were correlated with z -potential measurements, the dissociation behavior of the polymers and the powder surface chemistry. HCl and NH4-poly(acrylic acid), PAA, were used to stabilize alumina suspensions. A dual minima was found in the PAA dispersed suspensions containing MgO. The dispersant level of the first minima was a function of the concentration of sodium, shifting to lower dispersant levels for higher sodium concentrations. The second minima corresponded to the PAA dispersion of alumina. The critical coagulation concentration was measured for suspensions stabilized to a minimum in viscosity via electrostatic (HCl), inorganic electrosteric (sodium silicate and sodium hexa-metaphosphate), or organic electrosteric (NH4- and Napolymethacrylates, NH4- and Na-polyacrylates, and citric acid) dispersants. The salts investigated were the chlorides and sulfates of sodium, magnesium, and calcium. The thickness of the electrical double layer (d) around an alumina particle was calculated as a function of the electrolyte concentration and valence of the counter-ion, using a capacitance model. All of the suspensions coagulated at the same critical d value (~0.96 nm). Estimations of critical coagulation concentration using the critical d values obtained from MgCl2 additions agreed with rheological observations. The dependence of microstructure development on the type of dispersant used in the processing of alumina was investigated. Bulk density, and percent linear shrinkage measurements were used to evaluate the “green” density of pellets slip cast then calcined to 1000°C. Firing temperatures of 1200°C, 1400°C, and 1600°C were used to evaluate the densification process using bulk density and shrinkage measurements. SEM micrographs of pellets fired to 1400°C, polished, then thermally etched, display variations in morphology and grain size. The addition of Na+ ions to the suspensions resulted in abnormal grain growth, the organic component inhibited grain growth, and the inorganic dispersants severely inhibited grain growth. Binary-polymer/solvent and ternary-polymer/solvent interactions were observed using optical microscopy and light scattering (turbidity). The polymers investigated were poly(methacrylic acid) (PMAA), poly(vinyl alcohol) (PVA), and poly(ethylene glycol) (PEG). A ternary mixture design was used to evaluate the dependence of turbidity on polymer concentration. An increase in the degree of polymeric interaction was correlated with an increase in turbidity. The effects of pH, background electrolyte, electrolyte concentration, and temperature on the maximum in turbidity was evaluated using a statistical experimental design. The polymer concentrations, and the ratio of one polymer to another, were found to have the most profound effect on increasing turbidity. The solution pH and electrolyte conditions played important roles in the complexation of PMAA with PVA and PEG. An increase in the solution temperature decreased the turbidity of PMAA-PEG solutions, and increased the turbidity of PVA-PEG and PMAAPVA solutions. Based upon the information gathered, the microstructures developed when dextran sulfate and PEG were added to an aqueous alumina suspension, were the result of polymeric phase separation; the pores of which were thermodynamically stable. Using the knowledge gained from the investigations, a suspension can be processed outside the phase separating region by manipulating the thermodynamic properties of the polymer system. Phase separation can then be induced by changes in the suspension pH, electrolyte level, and temperature. The size, shape and connectivity of the pores can be controlled through kinetics. Although only demonstrated for alumina, the approach could be extended to other systems, providing an easily fabricated sample with tailored porosity.Item Atomistic Simulation of Surface Structures and Energies of Alkaline Earth Hexa-Aluminates(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2004-04) Stohr, Darren; Cormack, AlastairAtomistic computer simulation techniques were used to model the surfaces of five crystal structures in the hexa-aluminate family. Calcium, strontium, and the theoretical barium hexa-alumunates with the magnetoplumbite structure and two barium β-alumina crystals were investigated. It was found in all the crystal structures that the [001] surface had the lowest surface energy. Each system modeled resulted in plate-like crystals. Coordination of the exposed surface ions and the density of ions on the surface was found to be the dominant factor in the energy of the surfaces. The relaxation of ions to positions above the original surface (thus a low coordination with the other ions) was found to increase the energy of the surfaces for all the crystal systems. The surface energy increased with increasing divalent cation size in the calcium and strontium magnetoplumbite surfaces. The theoretical barium magnetoplumbite had the lowest calculated overall surface energy value of the magnetoplumbite crystals. The lower values for barium magnetoplumbite were due to the rumpling of the oxygen layers above and below the mirror plane in the bulk crystal structure. The relaxed positions and the number of exposed divalent cations also had a large influence on the surface energy for a given orientation in these structures. The location of the Ba2+ ion plays only a minor role in the lowering of surface energies in the β-aluminas. The coordination of the surface ions, mostly the number of dangling O2- ions, and the reduction of polarization in the surface structure have the greatest impact on the surface energy of a given orientation. It was concluded that surface energy stabilization of barium magnetoplumbite was not possible. The overall energy reduction caused by the formation of the two barium β- alumina crystals cannot be overcome by the lower surface energy of adopting the theoretical magnetoplumbite structure. The effect of isovalent cation substitution defects on the stability of the theorectical barium magnetoplumbite was also investigated. Calculation of isovalent substitution defects of the divalent cations and the aluminum ion on the surface was also examined. It was found that the addition of such surface defects did not stabilize the magnetoplumbite structure.Item Atomistic Simulations of Defect Structures in Solid Oxide Fuel Cell Electrolytes(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2012-02) Wang, Bu; Cormack, AlastairThe defect structures in two promising intermediate temperature solid oxide fuel cell electrolytes, gadolinia-doped ceria (GDC) and scandia-doped zirconia (SDZ), were studied by atomistic computer simulations. In GDC, it was found that sub nano-scale defect clusters preferred a next-nearestneighbor, pyrochlore-type structure, and that they had a tendency to grow into larger clusters. For nano-scaled domains, however, the C-type rare earth structure, in which the dopants and vacancies are at nearest-neighbor sites, became more stable. It was suggested that nano-domains served as the precursor of phase separation and they could be easily formed during synthesis. Doping concentration limited the size of the nano-domains, and caused GDC to favor small pyrochlore-type clusters at lower concentrations, but C-type nano-domains at higher concentrations. As such, GDC was expected to show initially an increase in conductivity and then a decrease with increasing doping concentration. The lattice parameter of GDC should show the same trend and could be used as an indicator of the predominant defect structure. The cation mobility was another important factor limiting the size of defect clusters, and could be used to control the domain formations and thereby improve the electrolyte performance. It was also found that the defect structure in GDC could be modulated by strain through oxygen diffusing into or out of the nearest neighbor sites of dopants with an activation energy estimated to be 0.82 eV. Based on such a mechanism, an explanation of the “chemical strain/stress” phenomenon observed in gadolinia-doped ceria, as well as the benefit of zero or moderate tensile strain for electrolyte applications, was proposed. The phase system of SDZ, especially the cation ordering in the three rhombohedral phases, was studied with both classical empirical potentials and ab-initio methods utilizing the density functional theory. Characteristics of defect structures in SDZ at different concentrations were identified based on the structures in the phase system. The abilities of the two methods in simulating the structures and phase stability of the SDZ system were compared and evaluated.Item Aurivillius Phase Oxides for Photocatalytic Applications(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2010-09) Nichols, Eric; Misture, ScottThe systematic design of materials for energy production and remediation of environmental concerns, based on direct knowledge of the structural and optical absorption characteristics of layered and traditional perovskites, is desirable for use in rational photocatalyst development. Aurivillius phase ceramic oxides have been suggested as potential candidates for photocatalytic water splitting applications based on the structural similarities between this class of materials and titanium dioxide, namely, transition metals in octahedral coordination with oxygen. Structural characterization of the three-layer lanthanide titanate Aurivillius oxides Bi2A2Ti3O12 (A2 = La2, Pr2, Nd2, LaPr, LaNd, PrNd) via combined Rietveld refinements of x-ray and neutron powder diffraction data has revealed that these materials reside in the orthorhombic space group B2cb. We have demonstrated that the optical band gaps for the three-layer lanthanide titanates can be red shifted by as much as 0.3 eV via combined structural and electronegative (bismuth replacement) means and exhibit a Vegard type relationship between band gap and chemical composition over the range of compositions tested (A2 = La2, Pr2, Nd2, LaPr, LaNd, PrNd, LaBi, PrBi, NdBi, La0.5Nd0.5Bi, Pr0.5Nd0.5Bi, Bi2). Additionally, the band gaps for these materials can be correlated with a single TiO6 octahedron and the manipulation of its Ti-O bond lengths. A method of quantification of BX6 octahedral anion distortions in traditional ferroic perovskites and layered perovskites has been developed based on Rietveld refinement of neutron diffraction data and vectorial analysis. Quantification of the octahedral distortion characteristics of the archetype perovskites via a survey of data contained within the Inorganic Crystal Structure Database (ICSD) has been completed. A preliminary link between antiferroelectric double hysteresis behavior and octahedral distortions in traditional perovskites has been established for the compounds PbZrO3, Pb2WMgO6, PbHfO3 and NaNbO3. Similar to traditional perovskites, octahedral distortions in the layered perovskites have been demonstrated, quantified and shown to trend with an average A-site cations’ ionic radius below 1.4 Å. Anatase, the photocatalytic polymorph of titanium dioxide, exhibits a similar distorted TiO6 octahedral environment and its structure was analyzed and compared with that of the Aurivillius oxides.Item Bond Valence Structure Analysis of Doped Bismuth Sodium Titanate(Alfred University. Faculty of Ceramic Engineering. Kazuo Inamori School of Engineering, 2004) Walsh, Conor JamesThis study focuses on a lead free, high temperature ceramic capacitor material having the base composition of (Bi0.5 Na0.5) TiO3. The goal is to modify this base composition to create a material that has X7R-like dielectric behavior, while maintaining its inherently good high temperature dielectric properties. This will alleviate some circuit design problems, and will create a component that is less susceptible to drastic environmental changes. Areas of interest include aerospace and weapons system applications, motor control, geological down hole drilling equipment and many more. An extensive experimental compositional matrix, along with theoretical modeling, has been investigated to modify the base material to attain the goals set forth. Additions of Ba2+, Sr2+, Ca2+, Zr4+ and Sn4+ were investigated by the bond valence method and dielectric constant measurements. Strontium and tin additions were also studied using the Rietveld refinement method. Many other additions were made to the structure to study the modification of the dielectric response. Both single and multicomponent dopant systems were studied to try and create a material that would meet the goal of the project. Barium additions in bismuth sodium titanate (BNT) raised the value of relative permittivity and lowered the peak temperature to a minimum of 150°C. Strontium additions raised the relative permittivity value and lowered the peak temperature, while tin additions suppressed the peak relative permittivity and maintained a constant peak temperature. Both additions increased the lattice parameters as predicted by the bond valence method and shown experimentally by the Rietveld refinements. Calcium additions resulted in a decrease in Curie temperature. Calcium is a very small cation that has been found to substitute for B-site cations in some situations. This occurrence is difficult to determine, however the electrical behavior of the calcium doped system may give some insight to this problem. Zirconium additions up to about 5 mol % increased the shoulder in the curve near 200° C. Above this percentage, the peak relative permittivity was suppressed similarly to the tin doped system. The multi-component systems that were studied exhibited results that combined the behavior of each of the xiii individual components. This trend, along with the bond valence modeling was used to guide the direction of the project. The bond valence method was used to compare the measured and calculated lattice parameters for the strontium and tin doped samples. The results show that the theoretical calculations are within a few hundredths of an angstrom of the measured lattice parameters for the samples. This can be useful to calculate how the size of the unit cell will be modified by adding various dopants and for tolerance factor calculations. The tolerance factor calculations are useful for determining compositions to test the electrical properties of. From the tolerance factor calculations, a range has been determined that describes the composition level of morphotropic phase boundary compositions in bismuth sodium titanate.Item Characterization of Glass Microspheres for Cancer Hyperthermia(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2019-05) Daneault, Jeffrey; Wren, Anthony; Keenan, Timothy; LaCourse, WilliamHyperthermal treatment of cancer has historically been used as an adjuvant to radiotherapy, and while effective it typically was used on near-surface caners. Synthesis and characterization of glass microspheres to be inserted directly to a cancerous growth was conducted where sixteen compositions of glass were synthesized using the melt-quench method. The compositions were based 30SiO2-10P2O5-25GeO2-35CaO (mol%) with an increasing 5-20 mol% substituent (Gd2O3, Ho2O3, Fe2O3, and Mn2O3) in place of CaO. XRD was conducted on each glass and the samples were found to be semi-crystalline with calcium phosphate peaks. Thermal analysis showed a decrease in Tg with increasing substitution content and the Tg ranged from 590-890°C. Ion release studies of 1, 10, 100, and 1000 hr were conducted on the glass powders, and the amount of silica (Si) Ge, and substituent ions were determined. There was a decreasing trend of ion release with increasing gadolinium (Gd) and holmium (Ho) concentrations. The levels of ion release in the iron (Fe) and manganese (Mn) samples may limit their applicability with respect to implantation into the body. The Gd and Ho samples had extremely low ion release rates, even after 1000 hrs incubation in aqueous media. Optical transmission microscopy showed that the glass was successfully converted from particle form into micron sized spheres. The size of the spheres was independent of the Tg or the composition and the overall average diameter of the 16 compositions was 95.6 μm. A corrosion study with pH 4, 7, and 10 solutions, presented very minor traces of degradation on the samples surface post incubation in each pH solution. SEM analysis showed the typical types of defects in the spheres. These defects were total failure to melt, partial melting, surface pores,and air bubbles. There were also atypical scaffold, pocket, and concave defects. Characterization of the glass and microspheres show that there is potential for all the Gd and Ho samples to be used in the body for cancer hyperthermia.Item Characterization, Bioactivity and Antioxidant Capacity of Yttrium and Cerium Doped Glass-Ceramics(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2016-03) Placek, Lana; Wren, AnthonyCompositional modifications of traditional bioactive glasses were investigated to address adversity associated with the biological response after spinal cord injury (SCI); specifically the accumulation of calcium (Ca) and subsequent generation of reactive oxygen species (ROS). Studies have shown yttria and ceria to have direct antioxidant scavenging capacity and provide neuroprotection under in vitro conditions of oxidative stress. Therefore in this work, Ca is replaced by strontium (Sr) and yttrium (Y) and cerium (Ce) are incorporated at the expense of sodium (Na) in a 0.52SiO2-0.24SrO-(0.24- x)Na2O-xMO (where x = 0.08; MO = Y2O3 and CeO2) glass series. The structure, dissolution behavior and antioxidant capacity are first investigated for the glass series where excessive dissolution was found to cause fibroblast and osteoblast toxicity. In an effort to reduce dissolution, thermal processing was employed to create a glass-ceramic series. The glass-ceramic structure reduced solubility and eliminated osteoblast toxicity while maintaining a degree of ROS scavenging capacity. Studies evaluating the glassceramic bioactivity and in vitro observation of the interaction of these glass-ceramics with osteoblast and Schwann cells were then completed.Item Characterizing the Reduction of NixMg1-xAl2O4(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2012-04) Hill, Brenden; Misture, ScottThe reduction of NixMg1-xAl2O4 in H2 to form nickel metal and a remnant oxide was characterized by XRD, HTXRD, TGA, pycnometry, TEM, and SEM. The aim of the work was to investigate the dynamics of the system to better understand its capabilities and limitations for catalysis applications. ZrO2 was added to the majority of samples to discourage the transformation of metastable spinel phases to Ɵ or α-Al2O3. As the reduction progresses, one O2- is lost for each Ni2+ which reduces to Ni metal. The temperature of the onset of reduction was shown to vary by composition in flowing 4% H2/Ar via TGA, with NiAl2O4 beginning to reduce at ~ 780 °C. The onset temperature of lower nickel compositions were quite close to each other, starting at ~ 900 °C for Ni0.75Mg0.25Al2O4. Ni0.25Mg0.75Al2O4 and Ni0.5Mg0.5Al2O4 were shown to form Ni metal and a nonstoichiometric spinel of the same Mg-Al ratio as the starting composition. NiAl2O4 and Ni0.75Mg0.25Al2O4 were found to become unstable as full reduction was approached, and metastable spinel, Ɵ-Al2O3, and α-Al2O3 formed sequentially given sufficient time at temperature. A phase diagram was constructed in a previously uninvestigated region of the NiAl2O4 – MgAl2O4-Al2O3 ternary phase diagram using the phase stability of the remnant spinel as indication of the edge of the spinel stability phase field. Rietveld refinements were performed on all compositions reduced at temperatures from 650 to 1100 °C to quantify structural changes in the spinel and phase fraction, crystallite size and microstrain in all phases. The formation of non-stoichiometric spinel upon reduction was confirmed by density measurements of the reduced specimens using helium pycnometry. Significant progress was made towards understanding the dynamics of an important catalyst system. The majority of nickel metal was present as faceted crystallites on the surface, explaining previously observed high catalytic activities. Subsequent studies can use the phase stability and kinetic results of this work to identify additives to stabilize the metastable spinel structures. Good candidates were identified in ZrO2 and Nb2O5, and TiO2 was found to promote the formation of corundum.Item Charge Storage in Defect Engineered Oxide Nanosheets(New York State College of Ceramics at Alfred University. Inamori School of Engineering., 2022-02) Flint, Madeleine N.; Misture, Scott; Pilgrim, Steven; Tidrow, Steven; Shulman, HollyLayered δ-MnO2 (birnessite) exhibits a unique response to the reduction of Mn4+ to Mn3+, where the reduced Mn3+ Jahn-Teller distorted octahedron creates a 'surface Frenkel defect.' The reduced Mn3+O6 octahedron migrates out of the the plane of the sheet and creates a vacancy within the sheet. The charged defect content may be controlled during flocculation of exfoliated nanosheets by equilibrating the nanosheet suspension in a pH regulated environment. It has been shown earlier that charged defects in δ-MnO2 improve electrochemical properties by increasing capacitance beyond 300 F/g, decreasing charge transfer resistance by a factor of 10, and improving life cycle stability. Building on earlier work, the present study aims to understand the synthesis of layered MnO2 and Mn-containing layered perovskites and their chemomechanical response during charge and discharge. X-ray total scattering, X-ray absorption spectroscopy, and Raman spectroscopy were employed to probe the chemomechanical response during electrochemical cycling of MnO2 electrodes in a custom-built electrochemical cell. While surface Frenkel defect content remained constant throughout electrochemical cycling, reversible reduction of Mn4+ to Mn3+ occurred, presumably within the sheet. MnO2 floccules equilibrated at a pH of 2 and 4 underwent 17% and 13% reduction from Mn4+ to Mn3+ upon K+ intercalation, respectively. Such reductions caused mechanical deformation of porous MnO2 electrodes and was found to be dependent on defect content and degree of restacking of the nanosheets. Floccules with a low degree of nanosheet restacking experienced lateral expansion upon K+ insertion of 0.7% and 0.5% for equilibration at a pH of 2 and 4, respectively, with no change in the interlayer (basal) direction spacing. However, MnO2 nanosheet floccules with a high degree of restacking experienced a 1.1% and 1.2% lateral expansion upon charging and a contraction in their basal direction of 1.7% and 0.7% for pH 2 and 4 samples, respectively. The interlayer contraction has been noted earlier, but largely eliminating the sheet-to-sheet stacking provides direct access to knowledge of the in-sheet chemomechanical response. Microstructures of air-dried and freeze-dried floccules as well as floccules with varying degrees of surface Frenkel defect content were similar. Surface Frenkel defect content remained constant across processing variations such as drying conditions and degree of restacking when equilibrated to the same pH.Item CHEMICAL SYNTHESIS AND CHARACTERIZATION OF 3-LAYER Bi_{2-y}Pb_{y}Sr_{2}Nb_{2}Ti_{1-x}Al_{x}O_{12-δ} AURIVILLIUS IONIC CONDUCTORS(Alfred University. Faculty of Ceramic Engineering. Kazuo Inamori School of Engineering., 2003) Luisi, Brian SAurivillius phases of the type Bi_{2}Sr_{2}Nb_{2}TiO_{12} and Bi_{1.6}Pb_{0.4}Sr_{2}Nb_{2}Ti_{1-x}Al_{x}O_{12} (0.0 ≤ x ≤ 0.8) were synthesized by the polymerized complex method involving an organo-metallic precursor. The effect of raising the pH of the solution on the temperature of crystallization formation was investigated through the addition of ammonium hydroxide. Infrared (IR) and nuclear magnetic resonance (NMR) spectra were obtained at various points in the reaction to aid in developing a reaction mechanism. The spectroscopic data showed the formation of an ester as well as an amide with the addition of ammonium hydroxide after polymerizing to 170 °C. Inductively coupled plasma (ICP) spectroscopy qualitatively showed that bismuth, strontium, niobium and titanium ions were all volatilizing out with solvent evaporation. Pure Bi_{2}Sr_{2}Nb_{2}TiO_{12} was formed after heat treatment for 5 hours at 900 °C. High temperature x-ray powder diffraction showed crystalline phase formation beginning at 700 °C. Phase pure Aurivillius structures were obtained with firing temperatures as low as 700 °C when the solution pH was adjusted to 9.00. A solubility limit of aluminum was discovered for Bi_{1.6}Pb_{0.4}Sr_{2}Nb_{2}Ti_{1-x}Al_{x}O_{12} at x ≥ 0.4. For x ≥ 0.4 two additional phases that formed were identified as bismuth oxide and strontium-aluminum oxide by x-ray diffraction (XRD). Scanning electron microscope – backscattered electron (SEM-BSE) images confirmed the presence of two additional phases at x = 0.6 and x = 0.8. Total conductivity of Bi_{1.6}Pb_{0.4}Sr_{2}Nb_{2}Ti_{1- x}Al_{x}O_{12} at 1123 K ranged from 1.74 x 10-4 S•cm-1 for x = 0.0 to 4.76 x 10-3 S•cm-1 for x = 0.8 stemming from oxygen vacancy formation as well as the evolution of bismuth oxide past the solubility limit. La_{1-x}Sr_{x}CoO_{3} (0.1 ≤ x ≤ 0.9) ceramics were also synthesized by the polymerized complex method. Rietveld refinement of x-ray powder diffraction data indicated that La_{1-x}Sr_{x}CoO_{3} adopts a cubic unit cell from 0.9 ≥ x ≥ 0.7, ultimately distorting to a rhombohedral unit cell at x ≤ 0.6. The lattice parameter in the cubic unit cell ranged from 3.833(1) Å at x = 0.7 to 3.838(9) Å at x = 0.9. The lattice parameter and cell angle in the rhombohedral unit cell ranged from 5.3935(9) Å and 60.6866(9)° at x = 0.1 to 5.416(4) Å and 60.080(4)° at x = 0.6.Item Chemical Synthesis and Electrical Characterization of N=3 Aurivillius Phases(Alfred University. Faculty of Ceramic Engineering. Kazuo Inamori School of Engineering., 2004) Harvey, Steven P.The polymerized complex method was utilized to synthesize n=3 Aurivillius compounds based on the parent phase Bi_{2}Sr_{2}Nb_{2}TiO_{12}. Results show that this is a viable option to replace solid-state synthesis of these materials because of the good homogeneity of powders and the substantially shorter processing times. The Aurivillius materials studied cannot be prepared to high density without the assistance of hot pressing. Compounds substituting transition metals (Fe, Cr, Co) for titanium remained phase pure up to 50 atom% (dependent on the valance and cation size as expected). Samples prepared substituting lead for bismuth were clearly phase pure up to 15 atom%, and in the 15-50 atom% substitution range XRD patterns indicate that a lead oxide or bismuth oxide impurity phase may be present; however, these impurity phases were not visible in the SEM. Transition metal substitutions did not increase the electrical conductivity of the material, and lead substitutions in high concentration decreased the conductivity. The substitutions did not affect the shape of Cole-Cole impedance plots. An anomalous diffraction behavior was observed in the lead substituted series. Peaks mixed indices peaks having c-axis character broadened as the lead concentration increased. This could correspond to a crystallite size or stain effect; however, attempts to separate the two using XRD analysis were unsuccessful. The charge carrier was studied under four different atmospheres, ranging from pure oxygen to 500ppm of oxygen. The data indicated that the parent phase Bi_{2}Sr_{2}Nb_{2}TiO_{12} is an electronic conductor. Results for the transition metal substituted sample Bi_{2}Sr_{2}Nb_{2}Ti_{0.8}Fe_{0.2}O_{12} indicate the sample is an ionic conductor. The stability of the Aurivillius phase under reducing conditions at 1050°C was determined: at a PO_{2} of 10-3 atm a bismuth oxide impurity phase (if present) decomposes and the Aurivillius phase is stable for 30 hours. At a PO_{2} of 10-8atm the Aurivillius phase starts to break down after just 10hrs. At a PO_{2} of 10-12atm the Aurivillius phase completely breaks down after 10 hours.Item Colloid Formation in As2O3-Doped Gallium Silicate Glasses(New York State College of Ceramics at Alfred University. Kazuo Inamori School of Engineering., 2013-01) Bornstein, Kody; Sundaram, S.K.Colloid formation in As2O3-doped alkali galliosilicate glass was studied via reduction of Ga and As in a galliosilicate glass matrix. The colloids were formed by heat treatment of the glasses in a hydrogen H2 or deuterium D2 atmosphere. The heattreatment temperature and duration were varied in optimizing the nucleation and growth processes. X-ray diffraction (XRD), differential scanning calorimetry (DSC), ultravioletvisible- near infrared (UV-Vis-NIR), and Fourier transform infrared (FTIR) spectroscopies were used to study the kinetics and dynamics of the processes. Hydroxyl ion formation in these glasses was correlated to the formation of colloids of Ga or As or some combinations of thereof. Colloid formation was supported by environmental scanning electron microscopy (SEM) and energy dispersion spectrometer (EDS). Absorbance versus (1/λ4), (1/nm4) plots suggested Rayleigh scattering, though quantum size effects could not be experimentally verified. Square root dependence of heattreatment time on the change in IR absorbance suggested a diffusion-controlled process. Spectroscopic evidence showed increasing hydroxyl concentration with treatment time in hydrogen atmosphere, while hydroxyl concentration decreased in deuterium atmosphere due to the removal of pre-existing hydroxyl and isotope exchange.