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Displaying 1651 - 1675 of 1729

Bond Lengths in Strained Semiconductor Alloys

May 1, 1999

Author(s)

Joseph C. Woicik

The bond lengths in a series of strained, buried Ga1-xInxAs thin-alloy films grown coherently on GaAs(001) and InP(001) substrates have been determined by high-resolution extended x-ray absorption fine-structure and diffraction anomalous fine-structure

A Crystalline Polymer Morphologist's Perspective on the Occasion of the Centenary of the Foundation of the American Physical Society

April 1, 1999

Author(s)

Freddy A. Khoury

Biographical commentary: A Crystalline Polymer Morphologist's Perspective on the Occasion of the Centenary of the Foundation of the American Physical Society.

Generation of Different UHMWPE Particle Shape by Wear Through Surface Texturing

April 1, 1999

Author(s)

H. W. Fang, M C. Shen, U Cho, John A. Tesk, A Christou, Stephen M. Hsu

Ultra-high molecular weight polyethylene (UHMWPE) wear particles in replaced joints have been linked to biochemical reactions that eventually lead to loosening of prosthesis. Several studies have shown that UHMWPE produces a wide range of particle sizes

Effect of Electrode Layer on the Polydomain Structure of Epitaxial PbZr 0.2 Ti 0.8 O 3 Thin Films

March 15, 1999

Author(s)

S P. Alpay, V Nagarajan, Leonid A. Bendersky, Mark D. Vaudin, S Aggarwal, R Ramesh, Alexander L. Roytburd

PbZr 0.2Ti 0.8O 3(PZT) thin films with and without La 0.5Sr 0.5CoO 3(LSCO) electrodes were grown epitaxially on (001) SrTiO 3 (STO) at 650 C by pulsed laser deposition. The domain structure of the 400 nm thick PZT films with different electrode layer

Crystal Structures and Reference Powder Patterns of BaR 2 ZnO 5 (R=La, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, and Tm)

March 1, 1999

Author(s)

James A. Kaduk, Winnie Wong-Ng, W Greenwood, J Dillingham, B H. Toby

Reference x-ray patterns and the crystal structure of the lanthanide compounds, BaR 2ZnO 5, in which R=La, Nd, Sm, Eu, Gd, Dy, Ho, Y, and Er, were studied by x-ray Rietveld refinement technique. A structural trend was confirmed for this series of compounds

Microstructural Changes in YSZ Deposits During Annealing

March 1, 1999

Author(s)

Andrew J. Allen, J Ilavsky, Gabrielle G. Long, Jay S. Wallace, C C. Berndt, H Herman

Various methods have been applied to the microstructural characterization of thermally-sprayed depostis. However, coexisting anisotropic distributions of intra-splat cracks and interlamellar pores, and the broad size range of rounded globular pores, have

The Role of Feedstock Particle Size on the Microstructural Behavior of Plasma-Sprayed YSZ Deposits During Annealing

March 1, 1999

Author(s)

H Boukari, Andrew J. Allen, Gabrielle G. Long, J Ilavsky, Jay S. Wallace, C C. Berndt, H Herman

We have studied the microstructure of thick plasma-sprayed yttrium-stabilized zirconia deposits fabricated from different initial feedstock particle size (32, 47, 56 and 88) m in a series of mulitiple and Porod small-angle neutron scattering experiments

VAMAS Technical Working Area #3

March 1, 1999

Author(s)

George D. Quinn, E F. Begley

Technical Working Area #3, Ceramics of the Versailles Advanced Materials and Standards (VAMAS) project has conducted 12 projects and 12,000 experiments over 12 years. This website explains TWA3, and lists the key accomplishments and publications from the

Barium Hollandite-Type Compounds Ba x Fe 2x Ti 8-2x O 16 with x= 1.143 and 1.333

February 23, 1999

Author(s)

J. M. Loezos, Terrell A. Vanderah, A R. Drews

Experimental X-ray powder diffraction patterns and refined unit cell parameters for two barium hollandite-type compounds. Ba xFe 2xTi 8-2xO 16, with x = 1.143 and 1.333, are reported here. Compared to the tetragonal parent structure, both compounds exhibit

Ceramic Measures: News of the Ceramic Processing Characterization Consortium, February 1999

February 1, 1999

Author(s)

S Jahanmir

Newsletter, Ceramic Measures: News of the Ceramic Processing Characterization Consortium, February 1999, Vol. 3, Issue 1.

The Use of Cyclic Phosphazene Additives to Enhance the Performance of the Head/Disk Interface

January 29, 1999

Author(s)

H J. Kang, Q Zhao, F E. Talke, D J. Perettie, B M. DeKoven, T A. Morgan, Daniel A. Fischer, Stephen M. Hsu, C S. Bhatia

Phase separation of phosphazene additives in perfluoropolyalkylether (PFPAE) lubricants is investigated as a function of additive concentration and lubricant layer thickness. The tribological behavior of various phosphazene additive/lubricant mixtures is

Wear Induced Molecular Orientation in Ultra High Molecular Weight Polyethylene (UHMWPE) Measured by Soft X-Ray Adsorption

January 29, 1999

Author(s)

Daniel A. Fischer, S Sambasivan, M C. Shen, Stephen M. Hsu

Molecular orientation in ultra high molecular weight polyethylene (UHMWPE) when it is subjected to wear is important in understanding the basic wear processes for this material. Current methods of inferring or deducing orientation information for UHMWPE

Effects of Wear Motion on Ultra High Molecular Weight Polyethylene (HMWPE) Molecular Orientation

January 28, 1999

Author(s)

S Sambasivan, Daniel A. Fischer, M C. Shen, Stephen M. Hsu

In a human hip joint, the motion is complex and consists of flexion/extension, abduction, and adduction. Laboratory studies have shown that these motions increase wear significantly. The aim of this study is to measure the change in molecular orientation

Simple Empirical Cluster Expansion Hamiltonians for Modeling Cation Order-Disorder in A(B'^d1/3B2/3)O3 Perovskites Such as Pb(Mg1/3Nb2/3)O3

January 15, 1999

Author(s)

Benjamin P. Burton

Brute force exploration of the simple cubic effective cluster interaction space indicates that linear triplet interaction is both necessary and sufficient to stablizde a P3ml ground state, and a P3ml Fm - 3m transition at 4.5183

Effect of Film Composition on the Orientation of (Ba,Sr)TiO 3 Grains in (Ba,Sr) y TiO 2+y Thin Films

January 12, 1999

Author(s)

Debra L. Kaiser, Mark D. Vaudin, L D. Rotter, John E. Bonevich, J T. Armstrong

(Ba,Sr) yTiO 2+y thin films with 0.34 {1-xSr xTiO 3 (x {aproximately equal to} 0.06) and an amorphous phase. The orientation of the tetragonal Ba 1-xSr xTiO 3 grains (pure a axis, pure c axis, or a mix of the two) was found to be strongly dependent upon

Application of Neutron Interferometry to the Measurement of Thin Film Density

January 1, 1999

Author(s)

William E. Wallace, David L. Jacobson, Muhammad Arif, A I. Ioffe

The application of neutron interferometry to the measurement of the atom density of polymer thin films (

Assessment of Particle Size Measurement Techniques and Procedures: I. Identification and Characterization of a Model Powder System

January 1, 1999

Author(s)

Ajitkumar Jillavenkatesa, Vincent A. Hackley, G Y. Onoda

Particle size distribution of a powder system has been observed to be dependent upon the instrument and technique used for analysis. Often, different instruments based upon the same fundamental principle give different results for the same powder. This

Ceramics 1998 Programs and Accomplishments

January 1, 1999

Author(s)

Stephen W. Freiman

The mission of the Ceramics Division can be stated as follows:Work with industry, standards bodies, academia, and other government agencies in providing the leadership for the Nation's measurements and standards infrastructure for ceramic materials.The

Comparison of Classical and MALDI-TOF-MS Analysis of a Polystyrene Interlaboratory Sample

January 1, 1999

Author(s)

William R. Blair, B M. Fanconi, R J. Goldschmidt, Charles M. Guttman, William E. Wallace, S Wetzel, David L. VanderHart

Over the past several years, the use of MALDI-TOF-MS for analysis of synthetic polymers has increased significantly. As the number of polymer analyses by MALDI has increased, scrutiny of the MALDI results in comparison to classically derived values for Mw

Domain Structure and Interphase Dimensions in Poly(Urethaneurea) Elastomers Using DSC and SAXS

January 1, 1999

Author(s)

S G. Musselman, T M. Santosusso, J D. Barnes, L H. Sperling

Small-angle x-ray scattering (SAXS) and differential scattering calorimetry (DSC) were used to demonstrate distinct differences in domain size, phase separation, and hydrogen bonding in a series of segmented urethaneurea elastomers prepared from isocyanate

Domain Structure and Interphase Dimensions in Poly(Urethaneurea) Elastomers Using DSCand SAXS

January 1, 1999

Author(s)

S G. Musselman, T M. Santosusso, J D. Barnes, L H. Sperling

In-Line Dielectric Sensor for Chemical Composition Measurements in Molten Polymers

January 1, 1999

Author(s)

M M. McBrearty, Anthony J. Bur, S Perusich

We describe a dielectric sensor that incorporates a flow-through design so that it can be placed in-line on an extruder. Dielectric measurements have been successfully applied for measuring additive concentrations in polymer melts during extrusion

Living Poly(Alpha-Methylstyrene) Near the Polymerization Line. Vii. Molecular Weight Distribution in a Good Solvent

January 1, 1999

Author(s)

S S. Das, J Zhuang, A P. Andrews, S C. Greer, Charles M. Guttman, William R. Blair

Measurement of Thermal Conductivity Using Tmdsc: Solution to the Heat Flow Problem

January 1, 1999

Author(s)

S L. Simon, G B. McKenna

Mechanical and Swelling Behaviors of Rubber: a Comparison of Some Molecular Models With Experiment

January 1, 1999

Author(s)

W H. Han, F Horkay, G B. McKenna