Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two ﬂuorocarbon Gases Chf3 And Cf4, 2019 Singh Center for Nanotechnology
Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two ﬂuorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson
Protocols and Reports
Two reactive ion etching (RIE) processes were studied to show the relative etch selectivity between SiO2 and Si using two ﬂuorocarbon gases, CF4 and CHF3. Results show that CHF3 gives better selectivity (16:1) over CF4 (1.2 :1). On the other hand, the etch rate of SiO2 of CF4 is approximately 52.8 nm/min, faster than CHF3 (32.4 nm/min).
3d Bioprinting Of Stem Cells And Polymer/Bioactive Glass Composite Scaffolds For Bone Tissue Engineering, 2019 Missouri University of Science and Technology
3d Bioprinting Of Stem Cells And Polymer/Bioactive Glass Composite Scaffolds For Bone Tissue Engineering, Caroline Murphy, Krishna Kolan, Wenbin Li, Julie A. Semon, D. E. Day, Ming-Chuan Leu
Ming C. Leu
A major limitation of using synthetic scaffolds in tissue engineering applications is insufficient angiogenesis in scaffold interior. Bioactive borate glasses have been shown to promote angiogenesis. There is a need to investigate the biofabrication of polymer composites by incorporating borate glass to increase the angiogenic capacity of the fabri-cated scaffolds. In this study, we investigated the bioprinting of human adipose stem cells (ASCs) with a polycaprolac-tone (PCL)/bioactive borate glass composite. Borate glass at the concentration of 10 to 50 weight %, was added to a mixture of PCL and organic solvent to make an extrudable paste. ASCs suspended in Matrigel ...
Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, 2018 The University of Southern Mississippi
Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim
Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass ...
Electrochemical Behaviors Of The Electrodes For Proton Conducting Intermediate Temperature Solid Oxide Fuel Cells (It-Sofc), 2018 Florida International University
Electrochemical Behaviors Of The Electrodes For Proton Conducting Intermediate Temperature Solid Oxide Fuel Cells (It-Sofc), Shichen Sun
FIU Electronic Theses and Dissertations
Proton conducting intermediate temperature (600oC-400oC) solid oxide fuel cells (IT-SOFC) have many potential advantages for clean and efficient power generation from readily available hydrocarbon fuels. However, it still has many unsolved problems, especially on the anode where the fuel got oxidized and the cathode where oxygen got reduced. In this study, for the anode, the effects of hydrogen sulfite (H2S) and carbon dioxide (CO2) as fuel contaminants were studied on the nickel (Ni) based cermet anode of proton conducting IT-SOFC using proton conducting electrolyte of BaZr0.1Ce0.7Y0.1Yb0.1O3 (BZCYYb). Both low-ppm level H2S and low-percentage level CO2 caused ...
High-Temperature Monitoring Of Refractory Wall Recession Using Frequency-Modulated Continuous-Wave (Fm-Cw) Radar Techniques, 2018 Missouri University of Science and Technology
High-Temperature Monitoring Of Refractory Wall Recession Using Frequency-Modulated Continuous-Wave (Fm-Cw) Radar Techniques, Bivin Varghese, C. Deconick, G. Cartee, M. Velez, Robert E. Moore, R. Zoughi
Furnaces are among the most crucial components in the glass and metallurgical industry. Nowadays, furnaces are being operated at higher temperatures and for longer periods of time thus increasing the rate of wear on the furnace refractory lining. Consequently, there is a great need for a nondestructive tool that can accurately measure refractory wall thickness at high temperatures. In this paper the utility of a frequency-modulated continuous-wave (FM-CW) radar is investigated for this purpose.
Broad-Spectrum Antibacterial Characteristics Of Four Novel Borate-Based Bioactive Glasses, 2018 Missouri University of Science and Technology
Broad-Spectrum Antibacterial Characteristics Of Four Novel Borate-Based Bioactive Glasses, Megan Ottomeyer, Ali Mohammadkah, D. E. Day, David J. Westenberg
David J. Westenberg
Bioactive glasses have been developed for medical applications in the body for bone and tissue repair and regeneration. We have developed a borate-containing bioactive glass (13-93B3, referred to as B3), which is undergoing clinical trials to assess its wound-healing properties. To complement the healing properties of B3, metal ion dopants have been added to enhance its antimicrobial properties. Bioactive glasses doped with silver, gallium or iodine ions were found to have broad spectrum antimicrobial effects on clinically relevant bacteria including MRSA. While the B3 glass alone was sufficient to produce antibacterial effects on select bacteria, adding dopants enhanced the broad-spectrum ...
Thermal Properties Of Spinel Based Solid Solutions, 2018 Missouri University of Science and Technology
Thermal Properties Of Spinel Based Solid Solutions, Kelley R. Wilkerson
Kelley R. Wilkerson
"Solid solution formation in spinel based systems proved to be a viable approach to decreasing thermal conductivity. Samples with systematically varied additions of MgGa₂O₄ to MgAl₂O₄ were prepared and thermal diffusivity was measured using the laser ash technique. Additionally, heat capacity was measured using differential scanning calorimetry and modeled for the MgAl₂O₄-MgGa₂O₄ system. At 200⁰C thermal conductivity decreased 24% with a 5 mol% addition of MgGa₂O₄ to the system. The solid solution continued to decrease the thermal conductivity by 13% up to 1000⁰C with 5 mol% addition. The decrease in thermal conductivity ultimately resulted in a decrease in heat flux ...
Tool For Correlating Ebsd And Afm Data Arrays, 2018 Purdue University
Tool For Correlating Ebsd And Afm Data Arrays, Andrew Krawec, Matthew Michie, John Blendell
The Summer Undergraduate Research Fellowship (SURF) Symposium
Ceramic and semiconductor research is limited in its ability to create holistic representations of data in concise, easily-accessible file formats or visual data representations. These materials are used in everyday electronics, and optimizing their electrical and physical properties is important for developing more advanced computational technologies. There is a desire to understand how changing the composition of the ceramic alters the shape and structure of the grown crystals. However, few accessible tools exist to generate a dataset with the proper organization to understand correlations between grain orientation and crystallographic orientation. This paper outlines an approach to analyzing the crystal structure ...
Synthesis & Fundamental Formation Mechanism Study Of High Temperature & Ultrahigh Temperature Ceramics, 2018 Florida International University
Synthesis & Fundamental Formation Mechanism Study Of High Temperature & Ultrahigh Temperature Ceramics, Paniz Foroughi
FIU Electronic Theses and Dissertations
Borides and carbides of tantalum and hafnium are of great interest due to their ultrahigh temperature applications. Properties of these ceramics including oxidation resistance and mechanical properties might be further improved through solid solution/composite formation. Synthesis of single-phase TaxHf1-xC and TaxHf1-xB2 solid solution powders including nanopowders via carbothermal reduction (CTR) is complicated due to noticeable difference in reactivity of parent oxides with carbon, and also the low solubility of those oxides in each other. Moreover, for TaC-HfC system the solid solution may go through phase separation due to the presence ...
Synthesis, Processing, And Fundamental Phase Formation Study Of Czts Films For Solar Cell Applications, 2018 Florida International University
Synthesis, Processing, And Fundamental Phase Formation Study Of Czts Films For Solar Cell Applications, Osama Awadallah
FIU Electronic Theses and Dissertations
Copper zinc tin sulfide (Cu2ZnSnS4 or CZTS) kesterite compound has attracted much attention in the last years as a new abundant, low cost, and environmentally benign material with desirable optoelectronic properties for Photovoltaic (PV) thin film solar cell applications. Among various synthesis routes for CZTS thin films, sol-gel processing is one of the most attractive routes to obtain CZTS films with superior quality and low cost.
In this study, sol-gel sulfurization process parameters for CZTS thin films were systematically investigated to identify the proper process window. In addition, temperature dependent Raman spectroscopy was employed to monitor the ...
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., 2018 University of Louisville
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer
Electronic Theses and Dissertations
This thesis is an examination of two material systems derived from polylactic acid (PLA) and polyethylene glycol (PEG). PLA is a polymer commonly sourced from renewable sources such as starches and sugars. It is a relatively strong, biodegradable polymer, making it ideal for use in the body. Even though it has a relative high strength, PLA is also brittle leading to the use of plasticizers to increase flexibility. One such plasticizer is PEG, which is a material that can exist at room temperature as either a thin liquid, or a hard waxy solid depending on the molecular weight. The first ...
Model-Assisted Approach For Probability Of Detection (Pod) In High-Temperature Ultrasonic Nde Using Low-Temperature Signals, Prathamesh N. Bilgunde, Leonard J. Bond
Aerospace Engineering Publications
Advanced piezoelectric-based ultrasonic transducers offer the potential for in-coolant nondestructive testing (NDT) measurements at high temperatures (HTs), including during hot standby (~260°C) for liquid-sodium–cooled advanced small modular reactors. The reliability of the NDT measurements is typically quantified by the probability of detection (POD) measured at the corresponding temperature. Obtaining such data in liquid sodium is challenging. Using a model-assisted POD approach, a transfer function is reported that enables data obtained on low carbon steel specimens at room temperature to give an estimated POD at an HT. A primary source of the difference in POD between room temperature and ...
Covalently Crosslinked Organic/Inorganic Hybrid Biomaterials For Bone Tissue Engineering Applications, 2018 The University of Western Ontario
Covalently Crosslinked Organic/Inorganic Hybrid Biomaterials For Bone Tissue Engineering Applications, Dibakar Mondal
Electronic Thesis and Dissertation Repository
Scaffolds are key components for bone tissue engineering and regeneration. They guide new bone formation by mimicking bone extracellular matrix for cell recruitment and proliferation. Ideally, scaffolds for bone tissue engineering need to be osteoconductive, osteoinductive, porous, degradable and mechanically competent. As a single material can not provide all these requirements, composites of several biomaterials are viable solutions to combine various properties. However, conventional composites fail to fulfil these requirements due to their distinct phases at the microscopic level. Organic/inorganic (O/I) class II hybrid biomaterials, where the organic and inorganic phases are chemically crosslinked on a molecular scale ...
Thermodynamic Investigation Of La0.8sr0.2mno3±Δ Cathode, Including The Prediction Of Defect Chemistry, Electrical Conductivity And Thermo-Mechanical Properties, Shadi Darvish
FIU Electronic Theses and Dissertations
Fundamental thermodynamic investigations have been carried out regarding the phase equilibria of La0.8Sr0.2MnO3±δ (LSM), a cathode of a solid oxide fuel cell (SOFC), utilizing the CALculation of PHAse Diagram (CALPHAD) approach. The assessed thermodynamic databases developed for LSM perovskite in contact with YSZ fluorite and the other species have been discussed. The application of computational thermodynamics to the cathode is comprehensively explained in detail, including the defect chemistry analysis as well as the quantitative Brouwer diagrams, electronic conductivity, cathode/electrolyte interface stability, thermomechanical properties of the cathode and the impact of gas ...
A Preliminary Study Of Smithport Plain Bottle Morphology In The Southern Caddo Area, 2018 Center for Regional Heritage Research, Stephen F. Austin State University
A Preliminary Study Of Smithport Plain Bottle Morphology In The Southern Caddo Area, Robert Z. Selden Jr.
This study expands upon a previous analysis of the Clarence H. Webb collection, which resulted in the identification of two discrete shapes used in the manufacture of the base and body of Smithport Plain bottles. The sample includes the Smithport Plain bottles from the Webb collection, and four new bottles: two previously repatriated specimens in the Pohler Collection, and two from the Mitchell site (41BW4) to test whether those specimens align morphologically with the Belcher Mound or Smithport Landing specimens. Results indicate significant allometry and a significant difference in Smithport Plain body and base shapes for bottles produced at the ...
Assisted Development Of Mesophase Pitch With Dispersed Graphene And Its Resulting Carbon Fibers, 2018 University of Kentucky
Assisted Development Of Mesophase Pitch With Dispersed Graphene And Its Resulting Carbon Fibers, Aaron Owen
Theses and Dissertations--Mechanical Engineering
The efficacy of dispersed reduced graphene oxide (rGO) as a nucleation site for the growth of mesophase in an isotropic pitch was investigated and quantified in this study. Concentrations of rGO were systematically tested in an isotropic petroleum and coal-tar pitch during thermal treatments and compared to pitch without rGO. The mesophase content of each thermally treated pitch was quantified by polarized light point counting. Further characterization of softening temperature and insolubles were quantified. Additionally, the pitches with and without rGO were melt spun, graphitized, and tensile tested to determine the effects of rGO on graphitized fiber mechanical properties and ...
Optimal Sintering Temperature Of Ceria-Doped Scandia Stabilized Zirconia For Use In Solid Oxide Fuel Cells, 2018 University of Central Florida
Optimal Sintering Temperature Of Ceria-Doped Scandia Stabilized Zirconia For Use In Solid Oxide Fuel Cells, Amanda K. Assuncao
Honors Undergraduate Theses
Carbon emissions are known to cause decay of the Ozone layer in addition to creating pollutant, poisonous air. This has become a growing concern among scientists and engineers across the globe; if this issue is not addressed, it is likely that the Earth will suffer catastrophic consequences. One of the main culprits of these harmful carbon emissions is fuel combustion. Between vehicles, power plants, airplanes, and ships, the world consumes an extraordinary amount of oil and fuel which all contributes to the emissions problem. Therefore, it is crucial to develop alternative energy sources that minimize the impact on the environment ...
Processing Of Cubic Stabilized Zirconia Electrolyte Membranes For Electrolyte-Supported Single Cell Solid Oxide Fuel Cells Using Tape Casting, 2018 University of Central Florida
Processing Of Cubic Stabilized Zirconia Electrolyte Membranes For Electrolyte-Supported Single Cell Solid Oxide Fuel Cells Using Tape Casting, Arturo Coronado Rodriguez
Honors Undergraduate Theses
Electrochemical conversion devices are a developing technology that prove to be a viable and more efficient alternative to current environmentally friendly generation devices. As such, constant research has been done in the last few decades to increase their applications and reliability. One of these systems, and the focus of this research, is the single cell Solid Oxide Fuel Cell (SOFC). These systems are a developing technology which main caveat is the need of high operating temperatures and costs. As such, most multidisciplinary research has been focused on researching materials and/or processes that help mitigate the costs or lower the ...
Raman Spectroscopy Of The Skeleton Of The Coral Acropora Cervicornis, 2018 University of Central Florida
Raman Spectroscopy Of The Skeleton Of The Coral Acropora Cervicornis, Zachary C. Shepard
Honors Undergraduate Theses
Coral reefs are an important element of marine ecosystem that are critical to maintain a healthy environment. Unfortunately, in recent years coral reefs are doing poorly and many in parts of the ocean are simply dying. Therefore, study of coral’s structural response to external loads could answer what will happen with their structures, while they exhibit different types of loading. Therefore, the proposition of using in-situ micro-Raman spectroscopy to study skeletons of Acropora cervicornis was used. Coral skeleton samples I subjected to mechanical loading studied their vibrational properties by exciting the material with 532nm visible light. A uniaxial compressive ...
Bismuth Ferrite-Based Lead-Free Ceramics And Multilayers With High Recoverable Energy Density, 2018 University of Sheffield
Bismuth Ferrite-Based Lead-Free Ceramics And Multilayers With High Recoverable Energy Density, Dawei Wang, Zhongming Fan, Di Zhou, Amir Khesro, Shunsuke Murakami, Antonio Feteira, Quanliang Zhao, Xiaoli Tan, Ian M. Reaney
Materials Science and Engineering Publications
Lead-free ceramics with high recoverable energy density (Wrec) and energy storage efficiency (η) are attractive for advanced pulsed power capacitors to enable greater miniaturization and integration. In this work, dense bismuth ferrite (BF)-based, lead-free 0.75(Bi1−xNdx)FeO3-0.25BaTiO3 (BNxF-BT) ceramics and multilayers were fabricated. A transition from a mixed pseudocubic and R3c to a purely pseudocubic structure was observed as x increased with the optimum properties obtained for mixed compositions. The highest energy densities, W ∼ 4.1 J cm−3 and Wrec ∼ 1.82 J cm−3, were achieved for BN15F-BT, due to the enhanced breakdown field ...