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Osteolysis induced by UHMWPE wear particles has emerged as the critical failure mechanism of artifical joints. However, the detailed mechanism of osteolysis and bone resorption induced by wear particles leading to the loosening of the total joint
Polymer brushes have potential as end-tethered lubricants. Brush layers immersed in a good solvent must be compressed to ~16% of their equilibrium height before friction forces are measured. The same experiment in a solvent near the theta temperature will
M A. Sahiner, S W. Novak, Joseph Woicik, Y. Takamura, P B. Griffin, J D. Plummer
One of the important challenges in semiconductor industry is to sustain high concentration of dopant atoms electronically active in very small areas. In investigating the optimum post implantation treatment methods that will help to attain these conditions
Wear studies under lubricated conditions can be classified into two nominally distinct categories: investigations of thewear mechanisms active within the material, and studies of the degradation mechanisms active within the lubricant. Thetwo categories
The present work reports on the processes involved in the wear of hydroxyapatite sliding against slip-cast, glass-infiltrated alumina. Synthetic hydroxyapatite is used as a model material representing tooth enamel, while the alumina that was used is
Structural ceramics are used in diverse tribological applications due to their unique properties that include resistance to abrasion and erosion, resistance to corrosive wear, wear resistance at elevated temperatures, low density, and unique electrical
Formulas are given for the effective volumes and effective surfaces for cylindrical rods loaded in flexure. Strength scaling for specimen size usually depends upon whether the flaws are volume or surface distributed. Flexural loadings of rods of constant
Formulas for the effective volumes and effective surfaces for rectangular bars loaded in flexure are reviewed. The ratio of strengths from any two configurations, such as 3-point flexural to 4-point, is independent of whether the flaws are volume or
Kathleen M. Flynn, M Konaklieva, J P. Gu, Charles M. Guttman, S Wetzel
Polyethylenimine (PEI) is being used as a DNA transfection agent. Complexes of DNA and PEI are known to pass through the wall of a cell, and studies have reported that PEI s efficiency as a gene delivery vehicle depends on its molecular weight. Molecular
Partial (Auger) yield near edge X-ray absorption fine structure (NEXAFS) is a structural analytical technique that has been primarily used to measure thespatial orientation and chemical bonding of small molecules on solid (i.e., inorganic or semiconductor)
Charles E. Bouldin, A I. Frenkel, A V. Kolobov, I K. Robinson, J O. Cross, Y Maeda
Diffraction Anomalous Fine Structure (DAFS) and Extended X-Ray Absorption Fine Structure (EXAFS) measurements have been combined to determine short-range order (SRO) about a single atomic type in a sample of mixed amorphous and nanocrystalline phases
N Chawla, B V. Patel, M Koopman, K K. Chawla, R Saha, B R. Patterson, Lin-Sien H. Lum, Stephen A. Langer
While it is well recognized that microstructure controls the physical and mechanical properties of a material, the complexity of the microstructure often makes it difficult to simulate by analytical or numerical techniques. In this paper we present a
Andrew J. Allen, Norman F. Berk, J Ilavsky, Gabrielle G. Long
Various authors have recognized the power of multiple small-angle neutron scattering (MSANS) analysis in providing information on coarse, concentrated microstructures involving micrometer length-scales larger than are accessible in conventional small-angle
Vincent A. Hackley, J Patton, Lin-Sien H. Lum, R Wasche, H Abe, M Naito, Y Hotta, H Pendse
Alumina suspended in aqueous electrolytic solution was used as a model ceramic suspension to investigate the measurement precision and influencing factors for the determination of the isoelectric point (IEP) in moderately concentrated systems. Techniques
We study the molecular orientation in semifluorinated (F 3C(CF 2) 8(CH 2) 2-, F8H2) self-assembled monolayers (SAMs) prepared by vapor deposition of mono- (m-F8H2), di- (d-F8H2) and trichloro (t-F8H2) organosilanes on flat silica-covered substrates. Near
S A. Prosandeev, Eric J. Cockayne, Benjamin P. Burton, V Trepakov, S Kapphan, M Savinov, L Jastrabik
Experiments on K(0.957)Li(0.043)TaO(3) samples indicate two different relaxation processes (p and p/2). First-principles computations clarify the nature of these relaxations and yield good agreement with experiment.
Numerous biological and chemical studies involve the use of calcium hydroxyapatite Ca10(PO4)6(OH)2, HA. In this study detailed physicochemical characterization of hexagonal HA prepared from an aqueous solution was carried out employing different methods
Walter G. McDonough, Gale A. Holmes, Joy P. Dunkers
Multi-fiber model composites are being used to conduct fundamental studies into the nucleation of failure in fibrous composites. Current results have revealed that the nucleation of critical flaws in unidirectional fibrous composites may rely on the time
Adhesion at the fiber-matrix interface of composite is often related to a combination of factors such as mechanical interlocking, physico-chemical interactions, and chemical bonding of the fiber-matrix interphase region. We demonstrate the use of (self
As magnetic data storage technology moves towards higher areal data density with higher rotational speeds and lower flying heights, the propensity of severe sliding contacts at the head-disk interface is bound to increase. The tribological performance of
This manuscript summarizes the proceedings and conclusions of a workshop organized to address issues associated with particle size and size distribution characterization of nanaopowders. Presentations made during this workshop highlighted the strengths and
X Li, L Andruzzi, E Chiellini, Giancarlo Galli, Christopher K. Ober, A Hexemer, E K. Kramer, Daniel A. Fischer
Two families of narrow polydispersity poly(styrene)-based block copolymers bearing side groups containing both a phenyl ring and a para-linked semifluorinated side group were designed to produce stable low energy surfaces. The effects of the phenyl ring on
Igor Levin, T G. Amos, J Nino, Terrell A. Vanderah, C A. Randall, M T. Lanagan
Single-phase pyrochlore specimens of Bi 1.5Zn 0.92Nb 1.5O 6.92 were studied using combined electron, X-ray and neutron powder diffraction techniques. Rietveld refinements using neutron powder diffraction data confirmed an average pyrochlore structure A 2B
We report on studies probing the effect of ultraviolet (UV) radiation and ultraviolet/ozone treatment (UVO), on the modification of poly(dimethyl siloxane) (PDMS) networks. The effect of the UV light wavelength and ambient conditions on the surface
Executive SummaryIt has been a noteworthy year for the Ceramics Division. Our Division Chief, Stephen Freiman, was elevated to the post of Deputy Director of the Material Science and Engineering Laboratory. We wish him every success in that office, and we