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Full-Text Articles in Engineering

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 …


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.


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 …


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.


Prediction Of Effective Permittivity Of Diphasic Dielectrics Using An Equivalent Capacitance Model, Sandeep K. Patil, Marina Koledintseva, Robert W. Schwartz, Wayne Huebner Oct 2008

Prediction Of Effective Permittivity Of Diphasic Dielectrics Using An Equivalent Capacitance Model, Sandeep K. Patil, Marina Koledintseva, Robert W. Schwartz, Wayne Huebner

Electrical and Computer Engineering Faculty Research & Creative Works

An analytical model based on an equivalent capacitance circuit for expressing a static effective permittivity of a composite dielectric with complex-shaped inclusions is presented. The dielectric constant of 0-3 composites is investigated using this model. The geometry of the capacitor containing a composite dielectric is discretized into partial parallel-plate capacitor elements, and the effective permittivity of the composite is obtained from the equivalent capacitance of the structure. First, an individual cell diphasic dielectric (a high-permittivity spherical inclusion enclosed in a lower permittivity parallelepiped) is considered. The capacitance of this cell is modeled as a function of an inclusion radius/volume fraction. …


Freeform Fabrication Of Zirconium Diboride Parts Using Selective Laser Sintering, Ming-Chuan Leu, Erik B. Adamek, Tieshu Huang, Greg Hilmas, Fatih Dogan Aug 2008

Freeform Fabrication Of Zirconium Diboride Parts Using Selective Laser Sintering, Ming-Chuan Leu, Erik B. Adamek, Tieshu Huang, Greg Hilmas, Fatih Dogan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using the Selective Laser Sintering (SLS) process, both flexural test bars and 3D fuel injector components have been fabricated with zirconium diboride (ZrB2) powder. Stearic acid was selected as the binder. Values of SLS process parameters were chosen such that the green parts could be built with sharp geometrical features and that the sintered parts could have good mechanical properties. After binder burnout and sintering, the SLS fabricated ZrB2 test bars achieved 80% theoretical density, and the average flexural strength of the sintered samples was 195 MPa. These values demonstrate the feasibility of the SLS process for …


Microstructural Characterization Of Diode Laser Deposited Ti-6al-4v, Tian Fu, Zhiqiang Fan, Syamala R. Pulugurtha, Todd E. Sparks, Jianzhong Ruan, Frank W. Liou, Joseph William Newkirk Aug 2008

Microstructural Characterization Of Diode Laser Deposited Ti-6al-4v, Tian Fu, Zhiqiang Fan, Syamala R. Pulugurtha, Todd E. Sparks, Jianzhong Ruan, Frank W. Liou, Joseph William Newkirk

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser Direct Metal Deposition (DMD) is an effective approach to manufacturing or repairing a range of metal components. The process is a layer-by-layer approach to building up a three dimensional solid object. The microstructure influences mechanical properties of the deposited parts. Thus, it is important to understand the microstructural features of diode laser deposited parts. This paper presents a microstructure analysis of a diode laser deposited Ti-6Al-4V onto a Ti-6Al-4V substrate. laser deposited parts. This paper presents a microstructure analysis of a diode laser deposited Ti-6Al-4V onto a Ti-6Al-4V substrate.


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 …


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.


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.


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.


Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba₂Cu₃O₆₊ₓ, F. Stercel, T. Egami, H. A. Mook, M. Yethiraj, M. Arai, C. Frost, Fatih Dogan, J. H. Chung Jan 2008

Composition Dependence Of The In-Plane Cu-O Bond-Stretching Lo Phonon Mode In Yba₂Cu₃O₆₊ₓ, F. Stercel, T. Egami, H. A. Mook, M. Yethiraj, M. Arai, C. Frost, Fatih Dogan, J. H. Chung

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 …


Anomalous Magnetic Ordering In Prba₂Cu₄O₈ And Cmba₂Cu₃O₇, H. A. Blackstead, M. P. Smylie, William B. Yelon, Qingsheng Cai, Mehmet Kahveci Jan 2008

Anomalous Magnetic Ordering In Prba₂Cu₄O₈ And Cmba₂Cu₃O₇, H. A. Blackstead, M. P. Smylie, William B. Yelon, Qingsheng Cai, Mehmet Kahveci

Physics Faculty Research & Creative Works

A review of temperature-dependent magnetization data for nonsuperconducting PrBa2Cu4O8 and CmBa2Cu3O7 suggests that the failure of each to superconduct is related to the presence of Pr and Cm on their respective Ba sites. This defect is manifested, in each case, by short c-axis lattice parameters and anomalous high-temperature magnetic ordering which has been incorrectly attributed to ordering of the entire magnetic sublattice. Instead, it is shown that the anomalous high-temperature ordering as seen in the magnetization data is consistent with the ordering of magnetic ions substituted on the Ba site.


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 …


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.


Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum Jan 2008

Glass Transition Behavior Of Poly(Methyl Acrylate) End-Grafted By Atrp To Amorphous Silica, Manikantan B. Nair, Frank D. Blum

Chemistry Faculty Research & Creative Works

Ultra-thin polymer films attached to solid substrates (supported films) have attracted significant interest in recent years. Supported films are used in the design of advanced materials like photoresists, lubricants and other electronic devices. Glass transition temperatures (Tgs) of supported polymer films have also been of significant interest. The Tg has been shown to depend on the thickness of the polymer film on the surface and the inherent nature of the surface. The effect of end-grafting of a polymer chain to a surface, on the Tg of the polymer has been studied previously.1 Reports on the study of glass transition behaviors …


Thermal Analysis Of Adsorbed Poly(Vinyl Acetate) On Silica, Boonta Hetayothin, Frank D. Blum Jan 2008

Thermal Analysis Of Adsorbed Poly(Vinyl Acetate) On Silica, Boonta Hetayothin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The physical properties of polymers at interfaces can be quite different from those in bulk due to the interaction between the absorbed polymer and the surface. This phenomenon can be probed through the dynamic behavior of the polymer chains at the interface which can be experimentally probed by techniques such as nuclear magnetic resonance spectroscopy (NMR),1 viscoelasticity, and calorimetry. At the polymer-air interface, polymer chains have more flexibility than those at the polymer-substrate interface. On the other hand, at the silica-polymer interface, where chains are more restricted on the surface, a higher glass transition temperature (Tg) results as compared with …


Dynamics Of Adsorbed Pma-D₃ - Effect Of Substrate, Frank D. Blum, Burak Metin, Macduff O. Okuom Jan 2008

Dynamics Of Adsorbed Pma-D₃ - Effect Of Substrate, Frank D. Blum, Burak Metin, Macduff O. Okuom

Chemistry Faculty Research & Creative Works

In the last few years, our group has focused much of our attention on studying the dynamics of polymers adsorbed at interfaces. Much of our work, to date has been on labeled poly(vinyl acetate)-d3 (PVAc-d3)1 and poly(methyl acrylate)-d3 (PMA-d3)2 on silica. We have been able to probe the effects of adsorbed amount,3 molecular mass,4,5 and the effect of overlayer.6 These studies have provided a view of the adsorbed polymer consistent with a motional gradient in the layer with the more mobile segments being those at the air-polymer interface and the less-mobile segments at the substratepolymer interface. However, we have not …


Dynamics Of Pipa-D₇ On Silica Surface, Piyawan Krisanangkura, Frank D. Blum Jan 2008

Dynamics Of Pipa-D₇ On Silica Surface, Piyawan Krisanangkura, Frank D. Blum

Chemistry Faculty Research & Creative Works

Molecular motion of polymer chains is an important determinant in understanding the physical properties of polymeric materials. Glass transition temperature (Tg) is a physical property of polymers, which is of primary interest. The study of the dynamics of polymer segments assists in understanding the dependence of Tg on polymer structure.1 For decades, studies have addressed the molecular motion in various polymers. Some of them have probed the dynamics of polymer backbones.2,3 the properties of a polymer at an interface may change because of the type of polymer, the substrate, or other variables. The side chain of a polymer can also …