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Displaying 1276 - 1300 of 1721

Effect of Loading Rate Upon Conventional Ceramic Microindentation Hardness

June 1, 2002
Author(s)
George D. Quinn, P J. Patel, Isabel K. Lloyd
Dynamic micro-indentation hardness was evaluated for a steel, sintered silicon carbide, and an aluminum oxynitride. There was negligible effect upon Vickers hardness when loading rate was varied by almost three orders of magnitude.

Elastic Moduli Data for Polycrystalline Oxide Ceramics

June 1, 2002
Author(s)
R G. Munro
A compilation of elastic moduli data, including Young's modulus, shear modulus, bulk modulus, and Poisson's ratio, is presented for polycrystalline oxide ceramics. The data have been collected from the technical literature, either as reported in textual or

Grain Growth and Twin Formation in 0.74 PMN-0.26 PT

June 1, 2002
Author(s)
Jay S. Wallace, J M. Huh, J Blendell, C A. Handwerker
The mechanisms controlling normal and exaggerated grain growth in lead magnesium niobate-lead titanate (PMN-PT) ceramics have been investigated by varying the PbO-based liquid phase volume fraction from 0.03 to 0.6 and sintering temperature form 900 C to

Structural Study of Li 1+x-y Nb 1-x-3y Ti x+4y O 3 Solid Solutions

June 1, 2002
Author(s)
L Farber, Igor Levin, A Borisevich, I E. Grey, Robert S. Roth, P K. Davies
The structures of Lil+x-yNbl-,-3yTix+4yO3 solid solutions within the so-called M-phase field in the Li2O-Nb2O5-TiO2system were investigated using HRTEM and single crystal X-ray diffraction. The results demonstrated the phasefield is comprised of a

Unraveling the Symmetry of the Hole States Near the Fermi Level in the MgB 2 Superconductor

June 1, 2002
Author(s)
Y Zhu, A R. Moodenbaugh, G Schneider, J W. Davenport, T Vogt, Q Li, G Gu, Daniel A. Fischer, J Tafto
We use x-ray absorption spectroscopy (XAS) and electron energy loss spectroscopy (EELS) to study the near edge fine structure at the K-edge of boron in the superconductor M gB 2. We observe in XAS a peak of width 0.6 eV at the threshold of this K-edge

Accuracy and Reproducibility of X-Ray Texture Measurements on Thin Films

May 1, 2002
Author(s)
Mark D. Vaudin, G R. Fox, G -. Kowach
Rocking curve texture measurements were made on thin films of zinc oxide (ZnO) and platinum (Pt) using a powder x-ray diffractometer, and also, in the case of ZnO, an area detector. The intensity corrections for defocussing and other geometric factors were

Cracking in Ceramic/Metal/Polymer Trilayer Systems

May 1, 2002
Author(s)
H Zhao, P Miranda, Brian R. Lawn, X Z. Hu
Fracture and deformation in model brittle-outerlayer/metal-core/polymer substrate trilayer systems in concentrated loading are studied. Model systems for experimental study are fabricated from glass microscope slides glued with epoxy adhesive onto steel

Effect of Counterface Roughness on Abrasive Wear of Hydroxyapatite

May 1, 2002
Author(s)
Sergei Kalinin, S Jahanmir, L K. Ives
The present study was undertaken to evaluate the effect of surface roughness of glass-infiltrated alumina on the abrasive wear of hydroxyapatite using a pin-on-disk tribometer. Hydroxyapatite was used as a model material to simulate tooth enamel. The wear

In-Line Dielectric Monitoring During Extrusion of Filled Polymers

May 1, 2002
Author(s)
Anthony J. Bur, S C. Roth, M M. McBrearty
Dielectric measurements were made on clay filled polyethylene-ethyl vinyl acetate (EVA) copolymer nanocomposites during processing by extrusion. The results show that composites containing chemically treated clays display significant dielectric dispersions

Temperature Effects During Capillary Rheometry Testing

May 1, 2002
Author(s)
Anthony J. Bur, S C. Roth, H Lobo
A non-contact temperature monitoring technique based on fluorescence spectroscopy was used to measure the temperature of a polymer resin during capillary rheometry testing. Polyethylene and polycarbonate doped with a fluorescent dye, perylene, were used in

Tri-Alpha-Napthyl Benzene as a Crystalline or Glassy MALDI Matrix

April 19, 2002
Author(s)
Barry J. Bauer, Charles M. Guttman, Da-Wei Liu, William R. Blair
Tri-alpha-napthyl benzene (TANB) is used as a matrix in matrix-assisted laser desorption/ionization (MALDI) spectroscopy. Electrosprayed TANB is crystalline and has a melting point of 180 2 C. A glass of TANB is obtained with a glass transition temperature

Friction Measurements of Ultra-Thin Carbon Overcoats in Air

April 1, 2002
Author(s)
P M. McGuiggan, C S. Bhatia, D Bogy, W Fong, Stephen M. Hsu
The friction force as a function of humidity was measured between 5 nm thick carbon films coated onto mica surfaces. The friction was found to be proportional to the area of contact. The shear stress at 0%, 33%, and 100% humidity was measured to be 25 +6

Influence of Processing Rate and Formulation on the Interface Strength of Vinyl Ester/E-Glass Composites

April 1, 2002
Author(s)
Walter G. McDonough, Joy Dunkers, Gale A. Holmes, E Feresenbet, Y H. Kim, Richard~undefined~undefined~undefined~undefined~undefined Parnas
The single fiber fragmentation test was used to investigate the effect of gelation time on interfacial shear properties of fast reacting resin systems. We developed a processing system capable of producing single fiber fragmentation samples with gelation

Non-Equilibrium Pattern Formation in the Crystallization of Polymer Blend Films

April 1, 2002
Author(s)
V Ferreiro, Jack F. Douglas, James A. Warren, Alamgir Karim
The crystallization of polymeric and metallic materials normally occurs under conditions far from equilibrium. The morphologies formed reflect a competition between order associated with the symmetries of the equilibrium crystal geometry and disorder

Quadrupole Effects in Core and Valance Photoelectron Emission From Crystalline Germanium Measured Via a Spatially Modulated X-Ray Interference Field

April 1, 2002
Author(s)
E J. Nelson, Joseph C. Woicik, P Pianetta, I A. Vartanyants, J W. Cooper
Near an x-ray Bragg reflection, two x-ray beams (incident and reflected) with opposite wavevectors exist within the crystal to create an x-ray standing wave (XSW) interference field. The part of the photoelectron yield depending on quadrupole (and higher
Displaying 1276 - 1300 of 1721