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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Electron And Spin Transport In The Presence Of A Complex Absorbing Potential, Fatih Dogan, Wonkee Kim, C. Blois, Frank Marsiglio May 2008

Electron And Spin Transport In The Presence Of A Complex Absorbing Potential, Fatih Dogan, Wonkee Kim, C. Blois, Frank Marsiglio

Materials Science and Engineering Faculty Research & Creative Works

We examine the impact of a complex absorbing potential on electron transport both in the continuum and on a lattice. This requires the use of non-Hermitian Hamiltonians; the required formalism is briefly outlined. The lattice formulation allows us to study the interesting problem of an electron interacting with a stationary spin and the subsequent time evolution of the electron and spin properties as the electron is absorbed after the initial interaction. Remarkably, the properties of the localized spin are affected “at a distance” by the interaction of the (now entangled) electron with a complex potential.

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Integral Channels In Metal Components And Fabrication Thereof, Rajiv S. Mishra Apr 2008

Integral Channels In Metal Components And Fabrication Thereof, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

An internal channel in a metal body for use in applications where internal fluid flow within a metal body is desired, as in a heat exchanger. The internal channel is formed in the metal body by frictionally stirring with a pin plunged into the metal body, and traversing the metal body with the pin.

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Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba2cu3o6+X, F. Stercel, T. Egami, Herbert A. Mook, M. Yethiraj, J.-H. Chung, M. Arai, C. Frost, Fatih Dogan Jan 2008

Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba2cu3o6+X, F. Stercel, T. Egami, Herbert A. Mook, M. Yethiraj, J.-H. Chung, M. Arai, C. Frost, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

An inelastic pulsed neutron scattering study was performed on the dependence of the dispersion and spectral intensity of the in-plane Cu-O bond-stretching LO phonon mode on doped charge density. The measurements were made in the time-of-flight mode with the multiangle position sensitive spectrometer of the ISIS facility on single crystals of YBa2Cu3O6+x x=0.15, 0.35, 0.6, 0.7, and 0.95. The focus of the study is the in-plane Cu-O bond-stretching LO phonon mode, which is known for strong electron-phonon coupling and unusual dependence on composition and temperature. It is shown that the dispersions for the samples with x=0.35, 0.6, and 0.7 are …

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Thickness Effects On The Ac And Dc Electrical Behavior Of Rf-Sputtered Batio3 Nano-Capacitors With Pt And Ni Electrodes, James N. Reck, Matthew O'Keefe, Fatih Dogan Jan 2008

Thickness Effects On The Ac And Dc Electrical Behavior Of Rf-Sputtered Batio3 Nano-Capacitors With Pt And Ni Electrodes, James N. Reck, Matthew O'Keefe, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Nanoscale BaTiO3 capacitors were deposited on Si wafers at dielectric thicknesses of approximately 25, 50, 100, and 200 nm using RF-magnetron sputtering with either 25 nm thick Ni or Pt electrodes. Multiple DC and AC tests were conducted on these devices to determine the effects of BaTiO3 thickness on the measured dielectric behaviors. All films were observed to have non-linear responses for resistance, permittivity, and loss with respect to dielectric thickness. The permittivity was found to follow a standard dead layer model behavior with measured values ranging from approximately 350 to 1700 for Ni electrodes and approximately 100 …

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Characterization And Glass Formation Of Jsc-1 Lunar And Martian Soil Simulants, C. S. Ray, Sabhayu Sen, Signo Tadeu Dos Reis Jan 2008

Characterization And Glass Formation Of Jsc-1 Lunar And Martian Soil Simulants, C. S. Ray, Sabhayu Sen, Signo Tadeu Dos Reis

Materials Science and Engineering Faculty Research & Creative Works

The space exploration mission of NASA requires human and robotic presence for long duration beyond the low earth orbit (LEO), especially on Moon and Mars. Developing a human habitat or colony on these planets would require a diverse range of materials, whose applications would range from structural foundations, (human) life support, (electric) power generation to components for scientific instrumentations. A reasonable and cost-effective approach for fabricating the materials needed for establishing a self-sufficient human outpost would be to primarily use local (in situ) resources on these planets. Since ancient times, glass and ceramics have been playing a vital role on …

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Progress In Effect Of Jominy End Quench On The Microstructure And Mechanical Properties Of Cast Aluminum Alloys, Qingcai Liu, C. Lu, Joseph William Newkirk Jan 2008

Progress In Effect Of Jominy End Quench On The Microstructure And Mechanical Properties Of Cast Aluminum Alloys, Qingcai Liu, C. Lu, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

In this review, the current knowledge related to the relationship between the heat treatment process and the microstructure and mechanical properties of A356 aluminum alloys are summarized. The review also examines the use of the Jominy end quench (JEQ) specimen and its application to the examination of the effects of quench rate and subsequent processing. Using the design of experimental methods combined with the Jominy end quench technique, desired changes in microstructure and mechanical properties of alloys can be obtained. So, the experimental technique of the Jominy end quench was concerned in this work.

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Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Y⁢Ba2⁢Cu3⁢O6+X, Ferenc Stercel, Takeshi Egami, Herbert A. Mook, Mohana Yethiraj, J-H Chung, M. Arai, C. Frost, Fatih Dogan Jan 2008

Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Y⁢Ba2⁢Cu3⁢O6+X, Ferenc Stercel, Takeshi Egami, Herbert A. Mook, Mohana Yethiraj, J-H Chung, M. Arai, C. Frost, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

An inelastic pulsed neutron scattering study was performed on the dependence of the dispersion and spectral intensity of the in-plane Cu-O bond-stretching LO phonon mode on doped charge density. The measurements were made in the time-of-flight mode with the multiangle position sensitive spectrometer of the ISIS facility on single crystals of Y⁢Ba2⁢Cu3⁢O6+x (x=0.15, 0.35, 0.6, 0.7, and 0.95). The focus of the study is the in-plane Cu-O bond-stretching LO phonon mode, which is known for strong electron-phonon coupling and unusual dependence on composition and temperature. It is shown that the dispersions for the samples with …

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Using Science, Engineering, And Education To Address Water Supply Challenges In The Highlands Of Guatemala, Andrew Curtis Elmore, William Fahrenholtz Dec 2007

Using Science, Engineering, And Education To Address Water Supply Challenges In The Highlands Of Guatemala, Andrew Curtis Elmore, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

The Guatemalan Highlands is a Popular Destination for Non-Government Organizations Interested in Performing Relief Projects. U.S.-Based Organizations Such as Rotary International, Engineers Without Borders, and Various Religious Organizations Travel to Guatemala to Conduct Humanitarian Activities Which May Be Effective for the Short Term, But It is Not Clear that the Efforts Have a Systematic Impact. Students and Faculty at the University of Missouri-Rolla Have Systematically Studied Water Supply Issues Including Undergraduate and Graduate Research Projects and Undergraduate Engineering Courses Such as International Capstone Design. Materials Engineers Have Been Involved in the Study of Ceramic-Based Water Treatment Devices. These Microfilters Have …

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Enhanced Shrinkage Of Lanthanum Strontium Manganite (La0.90sr0.10mno3+Δ) Resulting From Thermal And Oxygen Partial Pressure Cycling, Benjamin P. Mccarthy, Larry R. Pederson, Harlan U. Anderson, Xiao Dong Zhou, Prabhakar Singh, Gregory W. Coffey, Edwin C. Thomsen Oct 2007

Enhanced Shrinkage Of Lanthanum Strontium Manganite (La0.90sr0.10mno3+Δ) Resulting From Thermal And Oxygen Partial Pressure Cycling, Benjamin P. Mccarthy, Larry R. Pederson, Harlan U. Anderson, Xiao Dong Zhou, Prabhakar Singh, Gregory W. Coffey, Edwin C. Thomsen

Materials Science and Engineering Faculty Research & Creative Works

Exposure of (La0.90Sr0.10)0.98MnO3+δ (LSM-10) to repeated oxygen partial pressure cycles (air/10 ppm O2) resulted in enhanced densification rates, similar to behavior shown previously due to thermal cycling. Shrinkage rates in the temperature range 700°-1000°C were orders of magnitude higher than Makipirtti-Meng model estimations based on stepwise isothermal dilatometry results at a high temperature. a maximum in enhanced shrinkage due to oxygen partial pressure cycling occurred at 900°C. Shrinkage was the greatest when LSM-10 bars that were first equilibrated in air were exposed to gas flows of lower oxygen fugacity than in …

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Quantum Mechanics Of Spin Transfer In Coupled Electron-Spin Chains, C. Y. Kim, Lucian Covaci, Fatih Dogan, Frank Marsiglio Sep 2007

Quantum Mechanics Of Spin Transfer In Coupled Electron-Spin Chains, C. Y. Kim, Lucian Covaci, Fatih Dogan, Frank Marsiglio

Materials Science and Engineering Faculty Research & Creative Works

The manner in which spin-polarized electrons interact with a magnetized thin film is currently described by a semi-classical approach. This in turn provides our present understanding of the spin transfer, or spin torque phenomenon. However, spin is an intrinsically quantum-mechanical quantity. Here, we make the first strides towards a fully quantum-mechanical description of spin transfer through spin currents interacting with a Heisenberg-coupled spin chain. Because of quantum entanglement, this requires a formalism based on the density matrix approach. Our description illustrates how individual spins in the chain time-evolve as a result of spin transfer.

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Transportation Fuel Research And Development: Statistically Validated Codes And Standards, Fatih Dogan Aug 2007

Transportation Fuel Research And Development: Statistically Validated Codes And Standards, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The recent establishment of the National University Transportation Center at MST under the "Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users," expands the research and education activities to include alternative transportation fuels and other issues that are at the forefront of society and the national agenda. UMR in partnership with MTI will establish a rural hydrogen transportation test bed for developing, demonstrating, evaluating, and promoting hydrogen-based technologies in a real-world environment. The State of Missouri is ideally suited to develop and demonstrate the proper operation of hydrogen highways in a rural setting, which represents over 25 percent …

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Preface, Judy Schneider, Rajiv S. Mishra, Thomas R. Bieler, Yuntian T. Zhu, Khaled B. Morsi, Viola L. Acoff, Eric M. Taleff, Ruslan Valiev Aug 2007

Preface, Judy Schneider, Rajiv S. Mishra, Thomas R. Bieler, Yuntian T. Zhu, Khaled B. Morsi, Viola L. Acoff, Eric M. Taleff, Ruslan Valiev

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Effects Of Surface-Deposited Nanocrystalline Chromite Thin Films On The Performance Of A Ferritic Interconnect Alloy, I. Belogolovsky, X. D. Zhou, H. Kurokawa, P. Y. Hou, S. Visco, H. U. Anderson Aug 2007

Effects Of Surface-Deposited Nanocrystalline Chromite Thin Films On The Performance Of A Ferritic Interconnect Alloy, I. Belogolovsky, X. D. Zhou, H. Kurokawa, P. Y. Hou, S. Visco, H. U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

LaCrO3 -Based nanocrystalline thin films, substituted with Sr and Zn and coated onto a Fe-26 atom % Cr Ebrite alloy were evaluated at 750-900°C as potential enhancers of oxide properties in ferritic alloy interconnects of a solid oxide fuel cell. It was found that at 750°C the coatings provided (i) lower oxidation rates, (ii) increased electrical conductivity, (iii) protection during 24 h cycling and at least 2375 h of isothermal oxidation, and (iv) a fine-grained and uniform oxide microstructure. Although after oxidation at 850°C the grains grew substantially and the scale seemed to be overgrowing the film, conductivity and …

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Continuous Steel Production And Apparatus, Kent D. Peaslee, Jörg Peter, D. G. C. Robertson, Brian G. Thomas, Lifeng Zhang Jun 2007

Continuous Steel Production And Apparatus, Kent D. Peaslee, Jörg Peter, D. G. C. Robertson, Brian G. Thomas, Lifeng Zhang

Materials Science and Engineering Faculty Research & Creative Works

A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

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Life Cycle Greenhouse Gas Emission Comparison Of Steel Products With Other Materials, Christopher P. Buterbaugh, Meghan C. Mcgrath, Justin K. Novotny, Zane T. Voss, Joseph M. Brunner, Kent D. Peaslee May 2007

Life Cycle Greenhouse Gas Emission Comparison Of Steel Products With Other Materials, Christopher P. Buterbaugh, Meghan C. Mcgrath, Justin K. Novotny, Zane T. Voss, Joseph M. Brunner, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

This paper outlines the background of Life-Cycle Inventory/ Life-Cycle Assessment (LCI/LCA) and reviews an undergraduate design project in progress at the University of Missouri - Rolla (UMR) comparing LCI/LCA of steel products with similar products produced from competing materials. GaBi 4 LCI/LCA software is being used to model LCI/LCA with a demonstration of the use of the software for a typical steelmaking operation.1 Future research utilizing the LCI/LCA methodology is being applied to compare the environmental impact of steel products to other alternative engineering materials. This work involves 13 undergraduate students working in four design teams under a FeMET design …

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Increasing Energy Efficiency Through Improvements In Ladle Materials And Practices, Kent D. Peaslee, Semen Naumovich Lekakh, Jeffrey D. Smith, Mangesh Vibhandik Jan 2007

Increasing Energy Efficiency Through Improvements In Ladle Materials And Practices, Kent D. Peaslee, Semen Naumovich Lekakh, Jeffrey D. Smith, Mangesh Vibhandik

Materials Science and Engineering Faculty Research & Creative Works

Steel foundry ladle practices play an important role in total energy efficiency of melting as well as influence casting quality. Extensive heat losses in the ladle could be associated with excessive superheating of the melt before tap which increases energy consumption, promotes oxidation of the melt and increases refractory consumption. A high cooling rate of the liquid metal in the ladle could also cause casting quality instability. The overall ladle heat balance and components of heat losses were analyzed using FLUENT and FACTSAGE software and validated with experimental data from both the UMR foundry and industrial foundries. The purpose of …

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Preparation Of Bioactive Glasses With Controllable Degradation Behavior And Their Bioactive Characterization, Aihua Yao, Deping Wang, Qiang Fu, M. N. Rahaman, Wen-Hai Huang Jan 2007

Preparation Of Bioactive Glasses With Controllable Degradation Behavior And Their Bioactive Characterization, Aihua Yao, Deping Wang, Qiang Fu, M. N. Rahaman, Wen-Hai Huang

Materials Science and Engineering Faculty Research & Creative Works

Bioactive glasses and ceramics have been widely investigated for bone repair because of their excel-lent bioactive characteristics. However, these biomaterials undergo incomplete conversion into a bone-like material, which severely limits their biomedical application. In this paper, borosilicate bioac-tive glasses were prepared by traditional melting process. The results showed that borosilicate glasses possessed high biocompatibility and bioactivity. In addition, when immersed in a 0.02 mol/L K2HPO4 solution, particles of a borate glass were fully converted to HA. The desirable conversion rate to HA may be achieved through the adjustment of the B2O3/SiO2 ratio. The results of XRD and FTIR analysis indicated …

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Ac Conductivity Relaxation Processes In Cacu₃Ti₄O₁₂ Ceramics: Grain Boundary And Domain Boundary Effects, Wei Li, Robert W. Schwartz Dec 2006

Ac Conductivity Relaxation Processes In Cacu₃Ti₄O₁₂ Ceramics: Grain Boundary And Domain Boundary Effects, Wei Li, Robert W. Schwartz

Materials Science and Engineering Faculty Research & Creative Works

The ac conductivity of CaCu₃Ti₄O₁₂ ceramics associated with electrical charge carrier motion (ions or vacancies) was investigated as a function of frequency at different temperatures. The long range migration of charge carriers within the ceramic is restricted by two kinds of insulating barriers, namely, grain boundaries and domain boundaries. The potential barriers associated with these boundaries lead to two anomalies in conductivity response and three frequency-dependent contributions to conductivity: long range diffusion of carriers, carrier migration localized within grains, and carrier migration localized within domains.

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Humidification Factors From Laboratory Studies Of Fresh Smoke From Biomass Fuels, D. E. Day, J. L. Hand, C. M. Carrico, Guenter Engling, W. C. Malm Nov 2006

Humidification Factors From Laboratory Studies Of Fresh Smoke From Biomass Fuels, D. E. Day, J. L. Hand, C. M. Carrico, Guenter Engling, W. C. Malm

Materials Science and Engineering Faculty Research & Creative Works

Measurements of smoke aerosol humidification factors were performed in a laboratory for different biomass fuel types and burn conditions. Two nephelometers simultaneously measured dry and humidified light scattering coefficients (bsp(dry) and bsp(RH), respectively), providing the first observations of the temporal evolution of the humidification factor (f(RH) = bsp(RH)/bsp(dry)) for fresh (minutes-old) smoke. Hygroscopic characteristics of the smoke aerosols varied with fuel type and fire conditions, with the mean f(RH) ranging from 1.01 to 1.95 for fresh minutes-old smoke for the relative humidity (RH) range of 70-94%. These f(RH) values exhibited temporal variability, with some fuels alternating from hygroscopic to nonhygroscopic …

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Microstructural Modification Of As-Cast Al-Si-Mg Alloy By Friction Stir Processing, Z. Y. Ma, S. R. Sharma, Rajiv S. Mishra Nov 2006

Microstructural Modification Of As-Cast Al-Si-Mg Alloy By Friction Stir Processing, Z. Y. Ma, S. R. Sharma, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing (FSP) has been applied to cast aluminum alloy A356 plates to enhance the mechanical properties through microstructural refinement and homogenization. the effect of tool geometry and FSP parameters on resultant microstructure and mechanical properties was investigated. the FSP broke up and dispersed the coarse acicular Si particles creating a uniform distribution of Si particles in the aluminum matrix with significant microstructural refinement. Further, FSP healed the casting porosity. These microstructural changes led to a significant improvement in both strength and ductility. Higher tool rotation rate was the most effective parameter to refine coarse Si particles, heal the …

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Composite (La, Sr)Mno3-Ysz Cathode For Sofc, Toshio Suzuki, Masanobu Awano, Piotr Jasinski, Vladimir Petrovsky, Harlan U. Anderson Oct 2006

Composite (La, Sr)Mno3-Ysz Cathode For Sofc, Toshio Suzuki, Masanobu Awano, Piotr Jasinski, Vladimir Petrovsky, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

(La, Sr) MnO3 (LSM)-Y doped ZrO2 (YSZ) composite was prepared using YSZ colloidal suspension (initial YSZ particle size ∼100 nm), YSZ and LSM polymer precursors on dense substrates at 800 °C annealing temperature. the results of a symmetrical LSM-YSZ composite cell test showed the area specific resistance for overpotential of 0.14 Ω cm2 at 800 °C, which indicated that the LSM-YSZ composite could be a potential candidate for cathode in SOFCs. the performance of the cell with the LSM-YSZ composite cathode and Ni-YSZ anode was investigated and the power density of about 0.26 W cm- 2 was obtained …

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Effect Of Friction Stir Processing On The Microstructure Of Cast A356 Aluminum, Z. Y. Ma, S. R. Sharma, Rajiv S. Mishra Oct 2006

Effect Of Friction Stir Processing On The Microstructure Of Cast A356 Aluminum, Z. Y. Ma, S. R. Sharma, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

Friction stir processing (FSP) was applied to cast A356 Al to modify the as-cast microstructure. FSP homogenizes and refines the cast microstructure, completely eliminates porosity, and creates a microstructure with fine Si particles (0.25-0.42 μm) distributed in a fine grain aluminum matrix (3-4 μm). Further, FSP parameters significantly influence microstructural development in the processed zone of cast A356 Al. Generally, higher tool rotation rate creates a more homogeneous microstructure. at lower tool rotation rates, a macroscopically visible banded structure characterized by a low density of coarse particles, was detected in the nugget zone. However, FSP parameters did not significantly influence …

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Enhancement Of Crystal Growth And Superconducting Properties Of Melt-Textured Yba2cu3o7−X Through Addition Of Baceo3 And Basno3, Oratai Jongprateep, Fatih Dogan Sep 2006

Enhancement Of Crystal Growth And Superconducting Properties Of Melt-Textured Yba2cu3o7−X Through Addition Of Baceo3 And Basno3, Oratai Jongprateep, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

The effects of additions of BaSnO3 in combination with BaCeO3 on the microstructure, crystal growth and superconducting properties of melt-textured YBa2Cu3O7−x (Y123) have been investigated. It has been reported that the addition of BaCeO3 to Y123 results in an increase in the critical current density. However, higher cerium concentrations affect the solidification process and inhibit the growth of melt-textured Y123 single crystals. BaSnO3 has been shown to restore the properties of Y123 with BaCeO3 additives. Increasing the amount of added BaSnO3 leads to refinement of Y211 particles, enhancement of …

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Mössbauer And Epr Spectra For Glasses And Glass-Ceramics Prepared From Simulated Compositions Of Lunar And Martian Soils, C. S. Ray, Signo Tadeu Dos Reis, W. M. Pontuschka, J. B. Yang, F. F. Sene, J. M. Giehl, Chang-Soo Kim, S. Sen Sep 2006

Mössbauer And Epr Spectra For Glasses And Glass-Ceramics Prepared From Simulated Compositions Of Lunar And Martian Soils, C. S. Ray, Signo Tadeu Dos Reis, W. M. Pontuschka, J. B. Yang, F. F. Sene, J. M. Giehl, Chang-Soo Kim, S. Sen

Materials Science and Engineering Faculty Research & Creative Works

In situ resource processing and utilization on planetary bodies is an important and integral part of NASA's space exploration program. within this scope and context, our general effort is primarily aimed at developing glass and glass-ceramic type materials using Lunar and Martian soils and exploring various application potentials of these materials for planetary surface operations. This paper reports the successful preparation of glasses from the melts of simulated composition of Lunar and Martian soils, and thermal and structural characterization using differential thermal analysis (DTA), Mössbauer and electron paramagnetic resonance (EPR) spectroscopy. Glass-ceramic materials were developed from these glasses using selective …

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Freeze-Spray Processing Of Layered Ceramic Composites, Qiang Fu, Oratai Jongprateep, Ashlee Abbott, Fatih Dogan Aug 2006

Freeze-Spray Processing Of Layered Ceramic Composites, Qiang Fu, Oratai Jongprateep, Ashlee Abbott, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Thermal gradients and associated stresses are critical in designing with ceramic composites having low thermal conductivity. In order to reduce the stresses from thermal gradients, compositional gradients are employed in designing of composite structures. This study addresses development of freeze-spray process to fabricate layered ceramic structures with controlled layer thickness and microstructural development. The composites were processed by spraying of ceramic slurries with low binder content and relatively high solids loadings (up to 40 vol%) on a cooled substrate. The frozen parts were freeze-dried and sintered at elevated temperatures. The relationship between microstructural development and thermal expansion behavior of Al …

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Method For Fabricating Nanostructured Solid Oxide Fuel Cells And Cell Components, Harlan U. Anderson, X.-D. Zhou, Wayne Huebner Aug 2006

Method For Fabricating Nanostructured Solid Oxide Fuel Cells And Cell Components, Harlan U. Anderson, X.-D. Zhou, Wayne Huebner

Materials Science and Engineering Faculty Research & Creative Works

A method of fabricating a nanostructured solid oxide fuel cell includes dispersing ceria and doped ceria nanoparticles in a first colloidal solution, atomizing the first colloidal solution into a spray, depositing the spray onto a substrate to form a thin film electrolyte, dispersing a nanocomposite powder including ceria and CuO in the first solution, forming a second colloidal solution, atomizing the second colloidal solution into a second spray, and depositing the second spray over the thin film electrolyte as an interfacial layer.

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Method Of Preparing A Solid Oxide Fuel Cell, Greg Hilmas, Dustin Beeaff Aug 2006

Method Of Preparing A Solid Oxide Fuel Cell, Greg Hilmas, Dustin Beeaff

Materials Science and Engineering Faculty Research & Creative Works

A solid oxide fuel cell having a multichannel electrode architecture and method for preparing the same, the method including forming a first carbon laden composition, including a first thermoplastic binder, into a rod, applying a first zirconia laden composition, including a second thermoplastic binder, onto the rod to form a composite feed rod, extruding the composite feed rod to form a controlled geometry filament, bundling the extruded composite feed rod to form a multicellular feed rod, extruding the multicellular feed rod to form a multicellular rod, cutting the multicellular rod into multicellular discs, applying a zirconia laden material to one …

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Inelastic Deformation Behavior Of La0.6sr0.4feo3 Perovskite, Nina Orlovskaya, Harlan U. Anderson, Mykola Brodnikovskyy, Mykola Lugovy, Michael John Reece Aug 2006

Inelastic Deformation Behavior Of La0.6sr0.4feo3 Perovskite, Nina Orlovskaya, Harlan U. Anderson, Mykola Brodnikovskyy, Mykola Lugovy, Michael John Reece

Materials Science and Engineering Faculty Research & Creative Works

Inelastic deformation behavior of the rhombohedral La0.6Sr0.4FeO3 perovskite is reported. Such behavior is very similar to the ferroelastic deformation of LaCoO3 or lead zirconate titanate perovskites, except that no twin structure was found to exist in La0.6Sr0.4FeO3. the possible mechanisms responsible for such nonlinear deformation behavior are discussed. © 2006 American Institute of Physics.

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Dielectric Constant Of Particles Determined By Impedance Spectroscopy, Vladimir Petrovsky, Abhishek Manohar, Fatih Dogan Jul 2006

Dielectric Constant Of Particles Determined By Impedance Spectroscopy, Vladimir Petrovsky, Abhishek Manohar, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Electrical characterization of slurries prepared by mixing dielectric powders with solvents can be used to estimate dielectric properties of the particles. In particular, dielectric constant of the particles can be calculated from effective dielectric constant of the slurry measured at high frequency by using the Lorentz-Lorenz or similar equations based on mixing rules. Unfortunately, this approach leads to high margin of errors in dielectric constant estimation and is very sensitive to any slurry nonidealities such as sedimentation or agglomeration of particles. Impedance spectroscopy techniques are introduced to measure dielectric properties of particles at different frequency ranges. Dielectric constant of strontium …

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Simulations Of A New Continuous Steelmaking Process, Jorg Annie Peter, Kent D. Peaslee, D. G. C. Robertson May 2006

Simulations Of A New Continuous Steelmaking Process, Jorg Annie Peter, Kent D. Peaslee, D. G. C. Robertson

Materials Science and Engineering Faculty Research & Creative Works

A new continuous steelmaking process has been designed in an effort to reduce meltshop costs and increase productivity beyond the possibilities of current EAF-LMF-CC meltshops. This paper discusses possible operational performance based on industrially-verified kinetic, thermodynamic, and heat-transfer models. Dynamic simulations predict variations in steel chemistry and temperature, resulting from steel treatment and upsets. Savings in costs are projected because of increased metallic yield, lower energy requirements, more efficient use of deoxidants and alloys, fewer man-hours per ton, and decreased capital investment.

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