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Materials Science and Engineering Faculty Research & Creative Works

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Full-Text Articles in Materials Science and Engineering

Room-Temperature Protonic Conduction In Nanocrystalline Films Of Yttria-Stabilized Zirconia, Hugo J. Avila-Paredes, Enrique Barrera-Calva, Harlan U. Anderson, Roger A. De Souza, Manfred Martin, Zuhair A. Munir, Sangtae Kim Jul 2010

Room-Temperature Protonic Conduction In Nanocrystalline Films Of Yttria-Stabilized Zirconia, Hugo J. Avila-Paredes, Enrique Barrera-Calva, Harlan U. Anderson, Roger A. De Souza, Manfred Martin, Zuhair A. Munir, Sangtae Kim

Materials Science and Engineering Faculty Research & Creative Works

We report the results of our investigation on protonic conduction in 1 µm-thick polycrystalline films of 8 mol% yttria-stabilized zirconia (YSZ) with an average grain size of 17 nm prepared on sapphire substrate using a spin-coating process. Protonic conductivity of the films is found to be higher by over an order of magnitude (at 30 °C) than earlier reported values for nanocrystalline YSZ bulk ceramics with a similar grain size. This value is comparable to the oxygen-ionic conductivity of this material presented at about 400 °C. These results suggest that, besides grain size, the structural characteristics of the grain boundaries …

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Hydrogen Fuel Cell Analysis: Lessons Learned From Stationary Power Generation Final Report, Scott E. Grasman, John W. Sheffield, Fatih Dogan, Sunggyu Lee, Umit O. Koylu, Angie Rolufs Apr 2010

Hydrogen Fuel Cell Analysis: Lessons Learned From Stationary Power Generation Final Report, Scott E. Grasman, John W. Sheffield, Fatih Dogan, Sunggyu Lee, Umit O. Koylu, Angie Rolufs

Materials Science and Engineering Faculty Research & Creative Works

This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and …

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Investigation Of Creep Threshold Stresses Using In Situ Tem Straining Experiment In An Al-5y2o3-10sic Composite, S. P. Deshmukh, Rajiv S. Mishra, I. M. Robertson Apr 2010

Investigation Of Creep Threshold Stresses Using In Situ Tem Straining Experiment In An Al-5y2o3-10sic Composite, S. P. Deshmukh, Rajiv S. Mishra, I. M. Robertson

Materials Science and Engineering Faculty Research & Creative Works

Creep behavior of metal matrix composites is similar to dispersion strengthen alloys and characterized by the presence of a threshold stress below which the creep rate is negligible. This threshold stress is attributed, at least in dispersion-strengthened alloys, to dislocation particle interactions in which the detachment of the dislocations from the particle is the rate-limiting step. Creep experiments were performed on an Al-5Y2O3-10SiC composite in the temperature range of 473 and 573 K and the nature of the dislocation-particle interaction was determined by performing in situ straining experiments at elevated temperature in a transmission electron microscope. …

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The Strength Of Silicate Glasses: What Do We Know, What Do We Need To Know?, Charles R. Kurkjian, Prabhat K. Gupta, Richard K. Brow Mar 2010

The Strength Of Silicate Glasses: What Do We Know, What Do We Need To Know?, Charles R. Kurkjian, Prabhat K. Gupta, Richard K. Brow

Materials Science and Engineering Faculty Research & Creative Works

In the last few years, there has been increased interest in methods to improve the practical strength of inorganic glasses. during this same time period, new theoretical and experimental techniques have appeared. in this paper, we discuss this interest and indicate how and where these new techniques may help us to achieve our objective to increase the practical strength of glass. Our ability to measure the intrinsic inert strength of glass fibers as well as the development of stresses around indentations and scratches now allows us to attack these two important issues experimentally. Likewise, major advances have been made in …

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Functionally Graded Materials By Laser Metal Deposition (Preprint), Syamala R. Pulugurtha, Joseph William Newkirk, Frank W. Liou, Hsin-Nan Chou Mar 2010

Functionally Graded Materials By Laser Metal Deposition (Preprint), Syamala R. Pulugurtha, Joseph William Newkirk, Frank W. Liou, Hsin-Nan Chou

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of functionally graded materials (FGMs) by laser metal deposition (LMD) has the potential to offer solutions to key engineering problems over the traditional metalworking techniques. But the issues that need to be addressed while building FGMs are intermixing in the layers and cracking due to the residual stresses. This paper is to present the study of the effect of process parameters (laser power and travel speed) on the degree of dilution between the substrate (or, previous layer) and powder material for few metallurgical systems.

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Effect Of Friction Stir Processing On Fatigue Behavior Of An Investment Cast Al-7si-0.6 Mg Alloy, S. Jana, Rajiv S. Mishra, J. B. Baumann, G. Grant Feb 2010

Effect Of Friction Stir Processing On Fatigue Behavior Of An Investment Cast Al-7si-0.6 Mg Alloy, S. Jana, Rajiv S. Mishra, J. B. Baumann, G. Grant

Materials Science and Engineering Faculty Research & Creative Works

Cast aluminum alloys in general show poor fatigue performance due to the presence of defects. Friction stir processing (FSP) can be used as a tool to enhance the mechanical properties of cast alloys by eliminating such defects. in the present study FSP led to a five times improvement in fatigue life of an investment cast Al-7Si-0.6 Mg hypoeutectic alloy. the reason for such an enhancement was linked to the closure of casting porosities, which acted as crack nucleation sites in the as cast condition. Porosities acted as notches in the as cast alloy and led to an order of magnitude …

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Reaction Sintered Zirconium Carbide/Tungsten Composite Bodies And A Method For Producing The Same, Shi C. Zhang, Greg Hilmas, William Fahrenholtz Jan 2010

Reaction Sintered Zirconium Carbide/Tungsten Composite Bodies And A Method For Producing The Same, Shi C. Zhang, Greg Hilmas, William Fahrenholtz

Materials Science and Engineering Faculty Research & Creative Works

A method of sintering a composite body characterized by a transition metal carbide phase (such as a ZrC phase) substantially evenly distributed in a second, typically refractory, transition metal (such as W) matrix at ambient pressures, including blending a first predetermined amount of first transition metal oxide powder (such as ZrO2) with a second predetermined amount of second transition metal carbide powder (such as WC powder). Next the blended powders are mixed to yield a substantially homogeneous powder mixture and a portion of the substantially homogeneous powder mixture is formed into a green body. The body is fired …

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Friction Stir Processing Of Commercial Grade Marine Alloys To Enable Superplastic Forming, Christopher B. Smith, Arun Mohan, Rajiv S. Mishra, Murray Mahoney, Mike Miles, Scott M. Gillis, Lee M. Cerveny, Gerald Opichka Jan 2010

Friction Stir Processing Of Commercial Grade Marine Alloys To Enable Superplastic Forming, Christopher B. Smith, Arun Mohan, Rajiv S. Mishra, Murray Mahoney, Mike Miles, Scott M. Gillis, Lee M. Cerveny, Gerald Opichka

Materials Science and Engineering Faculty Research & Creative Works

The use of friction stir processing (FSP) on marine grade aluminum sheet has been investigated with the objective of locally enhancing the material properties. This can potentially allow low-cost commercial grade aluminum to be used in superplastic forming applications or further enhance the formability to allow more complex geometries to be formed. FSP has been demonstrated to enable super plasticity (uniform elongations >250%) in 5083-H116 over a range of friction stir processing conditions. © (2010) Trans Tech Publications.

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Impedance Spectroscopy Of Batio₃ Cubes Suspended In Lossy Liquids As A Physical Model Of Two-Phase System, Piotr Z. Jasinski, Vladimir Petrovsky, Fatih Dogan Jan 2010

Impedance Spectroscopy Of Batio₃ Cubes Suspended In Lossy Liquids As A Physical Model Of Two-Phase System, Piotr Z. Jasinski, Vladimir Petrovsky, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Impedance spectroscopy techniques were used for analysis of the physical model in a two-phase system toward determining of dielectric constant of dielectric particles suspended in liquids at various solids loading (volume fraction) levels. Model experimental studies were conducted using BaTiO3 as a dielectric material that was prepared as small cubes of uniform size (2×2×1 mm). Barium titanate (BT) cubes having a dielectric constant of 3850 were immersed in liquids of low dielectric constant and moderate electrical conductivity. Measured impedance spectra consisted of two semicircles, which were fitted for (R∥C)(R∥C) equivalent circuit. The parameters obtained from fitting were compared with the …

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Effect Of Phosphorus On Cleavage Fracture In Κ-Carbide, N. I. Medvedeva, Ryan A. Howell, David C. Van Aken, Julia E. Medvedeva Jan 2010

Effect Of Phosphorus On Cleavage Fracture In Κ-Carbide, N. I. Medvedeva, Ryan A. Howell, David C. Van Aken, Julia E. Medvedeva

Materials Science and Engineering Faculty Research & Creative Works

To understand the origin of cleavage fracture which dominates in Fe(Mn)-Al-C alloys at a high phosphorus concentration, we performed first-principles study of the phosphorus effect on ideal cleavage energy and critical stress in κ-carbide, Fe3 AlC, a precipitate in the austenitic alloys. We find that phosphorus has higher solubility in Fe3 AlC than in γ-Fe and sharply reduces the cleavage characteristics of κ-carbide. We show that strong anisotropy of the Fe-P bonds in Fe3 (Al,P) C under tensile stress, leads to the appearance of large structural voids and may facilitate crack nucleation.

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An Analysis Of Strength And Ductility Of Ultrafine Grained Al Alloys, R. Kapoor, P. S. De, R. S. Mishra Jan 2010

An Analysis Of Strength And Ductility Of Ultrafine Grained Al Alloys, R. Kapoor, P. S. De, R. S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

This paper brings together and compares data of various ultrafine grained (UFG) Al alloys processed through different routes. in general, the trend of decreasing ductility with increasing strength was observed for the UFG alloys. as compared to the coarse grained (CG) alloys, the UFG alloys show a lower ductility, a lower extent of work-hardening and a lower uniform elongation. Unlike the CG alloys, which show a large fraction of uniform to total elongation, in UFG alloys this fraction varies with processing technique. It is shown here that aging of some UFG Al alloys improves ductility. Further, it is shown that …

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Influence Of Fraction Of High Angle Boundaries On The Mechanical Behavior Of An Ultrafine Grained Al-Mg Alloy, R. Kapoor, N. Kumar, R. S. Mishra, C. S. Huskamp, K. K. Sankaran Jan 2010

Influence Of Fraction Of High Angle Boundaries On The Mechanical Behavior Of An Ultrafine Grained Al-Mg Alloy, R. Kapoor, N. Kumar, R. S. Mishra, C. S. Huskamp, K. K. Sankaran

Materials Science and Engineering Faculty Research & Creative Works

The mechanical behavior of ultrafine grained AA5052 processed through different techniques-rolled, annealed, friction stir processed (FSP) and equal channel angular pressed (ECAP)-were compared and correlated with microstructure. the microstructure was characterized using electron back scattered diffraction to obtain the boundary spacing, the fraction of high angle boundaries and to estimate the dislocation density from local misorientations. Both FSP and ECAP conditions had ultrafine boundary spacing, but the fraction of high angle boundaries was larger for the FSP condition. Tensile deformation carried out at 297K, and 10-3s-1 showed a lower work-hardening rate and recovery rate for FSP as compared to the …

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A Global Defect Chemistry Model For P-Type Mixed Ionic And Electronic Conductors, Xiao Dong Zhou, Harlan U. Anderson Dec 2009

A Global Defect Chemistry Model For P-Type Mixed Ionic And Electronic Conductors, Xiao Dong Zhou, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

A global defect chemistry model is presented to relate the properties of a variety of p-type perovskite conductors, including chromites, manganites, and ferrites, which can be tailored as mixed ionic and electronic conductors (MIECs). It is found that oxygen nonstoichiometry in these p-type MIECs can be correlated using reaction constant for oxygen vacancy generation. the values of reaction constant for oxygen vacancy formation can be obtained by simulating the electronic conductivity as a function of oxygen activity and temperature with the existing global model that is based on the concept of localized electron holes. the global defect chemistry model allows …

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Effect Of Stress Ratio On The Fatigue Behavior Of A Friction Stir Processed Cast Al-Si-Mg Alloy, S. Jana, Rajiv S. Mishra, J. B. Baumann, G. Grant Nov 2009

Effect Of Stress Ratio On The Fatigue Behavior Of A Friction Stir Processed Cast Al-Si-Mg Alloy, S. Jana, Rajiv S. Mishra, J. B. Baumann, G. Grant

Materials Science and Engineering Faculty Research & Creative Works

The effect of friction stirs processing (FSP) on the fatigue life of a cast Al-7Si-0.6 Mg alloy at stress ratios of R = 0 and R = -1 was evaluated. Two types of specimen geometry were used for the FSPed condition, through thickness processed and partial thickness processed. at R = 0, the microstructural refinement enhanced the fatigue life by a factor of 15, whereas at R = -1 the improvement in fatigue life was 5-fold. in light of these observations, various closure mechanisms were examined. © 2009 Acta Materialia Inc.

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Continuous Steel Production And Apparatus, Kent D. Peaslee, Jörg Peter, D. G. C. Robertson, Brian G. Thomas, Lifeng Zhang Nov 2009

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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Emerging Nonequilibrium Bound State In Spin-Current-Local-Spin Scattering, Fatih Dogan, Lucian Covaci, Wonkee Kim, Frank Marsiglio Sep 2009

Emerging Nonequilibrium Bound State In Spin-Current-Local-Spin Scattering, Fatih Dogan, Lucian Covaci, Wonkee Kim, Frank Marsiglio

Materials Science and Engineering Faculty Research & Creative Works

Magnetization reversal is a well-studied problem with obvious applicability in computer hard drives. One can accomplish a magnetization reversal in at least one of two ways: application of a magnetic field or through a spin current. The latter is more amenable to a fully quantum-mechanical analysis. We formulate and solve the problem whereby a spin current interacts with a ferromagnetic Heisenberg spin chain, to eventually reverse the magnetization of the chain. Spin flips are accomplished through both elastic and inelastic scattering. A consequence of the inelastic-scattering channel, when it is no longer energetically possible, is the occurrence of a nonequilibrium …

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Functionally Graded Materials By Laser Metal Deposition, Syamala Rani Pulugurtha, Joseph William Newkirk, Frank W. Liou, Hsin-Nan Chou Aug 2009

Functionally Graded Materials By Laser Metal Deposition, Syamala Rani Pulugurtha, Joseph William Newkirk, Frank W. Liou, Hsin-Nan Chou

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of functionally graded materials (FGMs) by laser metal deposition (LMD) has the potential to offer solutions to key engineering problems over the traditional metal-working techniques. But the issues that need to be addressed while building FGMs are intermixing in the layers and cracking due to the residual stresses. This paper is to present the study of the effect of process parameters (laser power and travel speed) on the degree of dilution between the substrate (or, previous layer) and powder material for few metallurgical systems.

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Dislocation-Particle Interaction At Elevated Temperatures, Rajiv S. Mishra Jul 2009

Dislocation-Particle Interaction At Elevated Temperatures, Rajiv S. Mishra

Materials Science and Engineering Faculty Research & Creative Works

There is a major difference in dislocation-particle interaction at low and elevated temperatures. This article will only discuss the historic development of and the current understanding of the interaction of dislocations with non-shearable particles at elevated temperatures. It will show that the understanding of repulsive-attractive transition in dislocation-particle interaction at elevated temperatures has undergone remarkable change and is at a level where a physics-Based high-temperature strengthening framework can be developed. © TMS 2009.

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Freeze-Spray Deposition Of Layered Alumina/Zirconia Composites, Qiang Fu, Oratai Jongprateep, Ashlee Abbott, Fatih Dogan Apr 2009

Freeze-Spray Deposition Of Layered Alumina/Zirconia Composites, Qiang Fu, Oratai Jongprateep, Ashlee Abbott, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Freeze-spray deposition (FSD) method is described for rapid fabrication of layered composites with controlled layer thickness and uniform microstructure. The graded alumina/zirconia composites are fabricated by FSD of ceramic slurries followed by freeze drying. Aqueous slurries with glycerol addition are sprayed on a cooled substrate using an automated 3D gantry system. Processing parameters such as viscosity of the ceramic slurries, composition and thickness of deposited layers as well as sintering conditions are investigated to optimize the fabrication process. Microstructural analysis of the fabricated composites revealed uniform and crack-free transitional layers indicating a strong interfacial bonding between the layers.

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Electrical Properties Of Phosphate Glasses, Andrea Mogus-Milankovic, Ana Santic, Signo Tadeu Dos Reis, D. E. Day Mar 2009

Electrical Properties Of Phosphate Glasses, Andrea Mogus-Milankovic, Ana Santic, Signo Tadeu Dos Reis, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized …

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Development Of Microbial And Enzymatic Fuel Cells For Bio-Inspired Power Sources, Fatih Dogan, Shelley Minteer Mar 2009

Development Of Microbial And Enzymatic Fuel Cells For Bio-Inspired Power Sources, Fatih Dogan, Shelley Minteer

Materials Science and Engineering Faculty Research & Creative Works

This report is based on some of the revolutionary concepts described in the Road Map on Bioinspired Power Systems within the AFRLRW Campus Challenge II. Development of biofuel cell concepts integrated with fuel regeneration and energy storage capabilities are proposed to create a compact and self-sustaining power system. The first part of this work identified a sediment based microbial fuel cell that could power small electronics and maintain electrical activity over long periods of time. AFRLRW does not feel that this work adequately addresses the original scope nor does it provide a basis on which to continue work. The second …

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Yttria Stabilized Zirconia As A Candidate For High Energy Density Capacitor, Oratai Jongprateep, Vladimir Petrovsky, Fatih Dogan Dec 2008

Yttria Stabilized Zirconia As A Candidate For High Energy Density Capacitor, Oratai Jongprateep, Vladimir Petrovsky, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

As one of the main components in power converters, dielectric capacitors can play crucial roles in facilitating power conversion in various applications, such as hybrid-electric and fuel cell vehicles. Capacitor reliability is a key challenge for development of high-performance capacitors. In this study, yttrium stabilized zirconia (YSZ) with various yttria concentrations were fabricated and tested for dielectric properties, such as breakdown strength and dielectric loss factors. The results indicated that the breakdown strength as high as 2 MV/cm could be achieved in YSZ samples with 10 mol% yttria. In addition, the dielectric loss factors of the samples were lower than …

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Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez Dec 2008

Improvements In Steel Melting Efficiency -- Industrial Trials, Kent D. Peaslee, Semen Naumovich Lekakh, Edith Martinez

Materials Science and Engineering Faculty Research & Creative Works

Industrial trials were completed to improve energy efficiency in steel melting. First, the benefits of increased chemical energy from an oxyfuel burner and a Co-Jet system in a basic 20 ton electric arc furnace (EAF) were studied. Observations and measurements were made during production before and after the installation of the two systems. The additional chemical energy improved energy efficiency and resulted in increased production. In addition, production using a basic EAF practice was compared to the traditional acid EAF practice. Second, an industrial trial using a 750 lb ladle with a combination of a lightweight alumina castable refractory and …

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Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich Dec 2008

Energy Efficiency In Steel Casting Production, Raymond Monroe, Kent D. Peaslee, R. Eppich

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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Using Automated Inclusion Analysis For Casting Process Improvements, Vintee Singh, Semen Naumovich Lekakh, Kent D. Peaslee Dec 2008

Using Automated Inclusion Analysis For Casting Process Improvements, Vintee Singh, Semen Naumovich Lekakh, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

Different industrial melting and ladle practices (deoxidation, slag, refractory types, etc.) used in steel foundries were analyzed and compared using an ASPEX automated inclusion analyzer for study of inclusions. The effects of deoxidation and pouring practices on the size, type and number of inclusions were evaluated for steel foundries equipped with induction and arc melting furnaces, with capacities ranging from 1 to 20 tons. Samples were collected from the furnace, ladle, and castings. Specific rules were developed for classification of inclusions by composition, size distribution and shape. Inclusion statistics, including composition, quantity, shape, and size during cast steel processing from …

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Structural Properties And Crystallization Of Sodium Tellurite Glasses, Kresimir Furic, Masa Rajic-Linaric, C. S. Ray, A. Šantić, Andrea Moguš-Milanković, D. E. Day Dec 2008

Structural Properties And Crystallization Of Sodium Tellurite Glasses, Kresimir Furic, Masa Rajic-Linaric, C. S. Ray, A. Šantić, Andrea Moguš-Milanković, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

The structural properties and crystallization behaviour of xNa2O-(100-x)TeO2 (0 <= x <= 33.3, x-% mole fraction) glasses have been investigated by Raman spectroscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The Raman spectra of glasses show systematic changes in structural units, from TeO4 trigonal bypiramids (tbps) to TeO3 trigonal pyramids (tps) with increasing Na2O content in glass. These structural changes are result of Te-eqOax-Te disruption and the formation of non-bridging oxygens (NBOs) in glass network. when heated at 623 K for 10 h glasses crystallized to different phases: alpha-TeO2, Na2Te4O9 and a new crystalline phase which is believed to be a polymorph of Na2Te2O5.

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N,N’-Bis(3,5-Di-T-Butylsalicylideneimine) Propanediamine And Its Some Tetradentate Schiff Base Complexes Synthesis, Characterization And Thermal Study, Fatih Dogan, M. Ulusoy, O. F. Ozturk, I. Kaya, B. Salih Nov 2008

N,N’-Bis(3,5-Di-T-Butylsalicylideneimine) Propanediamine And Its Some Tetradentate Schiff Base Complexes Synthesis, Characterization And Thermal Study, Fatih Dogan, M. Ulusoy, O. F. Ozturk, I. Kaya, B. Salih

Materials Science and Engineering Faculty Research & Creative Works

Several mononuclear Co (II), Ni (II), Cu (II) and Fe (II) complexes of tetradentate salpren-type diamine, obtained from 3,5-di-tert–butyl-2-hydroxybenzaldehyde and 1,3-diaminopropane have been prepared and characterized by analytical, spectroscopic (FTIR, UV-Vis) techniques, magnetic susceptibility measurements and thermogravimetric analyses (TG). The thermodynamic and thermal properties of complexes have been investigated. For further characterization direct insertion probe-mass spectrometry (DIP-MS) was used and the fragmentation pattern and also stability of the ions were evaluated. The characterization of the end products of the decomposition was achieved by X-ray diffraction. The thermal stabilities of metal complexes of N,N’-bis(3,5-di-t-butylsalicylideneimine) propane diamine ligand (L) were found as …

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Nanoparticulate Composites Of Melt Textured Yba2cu3o7−X Superconductors, Oratai Jongprateep, Fatih Dogan Aug 2008

Nanoparticulate Composites Of Melt Textured Yba2cu3o7−X Superconductors, Oratai Jongprateep, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

It has been shown that Nd1+xBa2−xCu3O7−x could exhibit a pronounced Jc(H) peak effect, which results in an enhancement of the critical current density under the medium range magnetic field. Additions of small quantities of Nd2O3 into Pt-doped YBa2Cu3O7−x (Y123) resulted in the formation of nanosized (30–60 nm) secondary phases which are expected to have a significant effect on superconducting properties of melt textured Y123 single crystals. By considering of solidification kinetics, effect of neodymium oxide and platinum addition on processing parameters of melt textured Y123 superconductors are …

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Glass And Glass-Ceramic Sealant Compositions, Richard K. Brow, Signo Tadeu Dos Reis, Glen Benson Jul 2008

Glass And Glass-Ceramic Sealant Compositions, Richard K. Brow, Signo Tadeu Dos Reis, Glen Benson

Materials Science and Engineering Faculty Research & Creative Works

A glass composition for use as a sealant or otherwise bonded to a fuel cell component, including from about 40 mol % to about 60 mol % RO; from about 2 mol % to about 10 mol % M2O3; and from about 35 mol % to about 45 mol % SiO2. R is selected from the group including strontium, calcium, magnesium and zinc and combinations thereof. M is selected from the group including aluminum, boron, lanthanum, iron and combinations thereof. The glass includes at least about 5 mol % ZnO. Upon heat treatment, the …

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Improving Steel Cleanliness Through Slag Refining, Sarina Bao, Xinhua Wang, Lifeng Zhang, Shufeng Yang, Kent D. Peaslee May 2008

Improving Steel Cleanliness Through Slag Refining, Sarina Bao, Xinhua Wang, Lifeng Zhang, Shufeng Yang, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

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