Materials Literature
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We present an algorithm to simulate the packing of large samples of spheres chosen from a truncated log-normal distribution for either correlated or uncorrelated distributions. Use of a concept known as the porosity index provides a means to control the final porosity of a packed sample within a range that spans limit…
The crystal structures of four hydroxylapatite (HA) samples prepared from solutions in the presence of 10, 15, 25 and 30 Mg-atom-% have been investigated by X-ray powder pattern fitting. The total magnesium content of the solid samples, as determined by chemical analysis, was 4.9, 14.1, 20.4 and 30.6 Mg-atom-%, respec…
Magnesium hydroxide, Mg(OH) 2 : M r = 58.3, trigonal, P {\bar 3} m 1, a = 3.148 (1), c = 4.779 (2) Å, V = 41.015 Å 3 , D x = 2.36 g cm −3 at room temperature; a = 3.145 (1), c = 4.740 (2) Å, V = 40.602 Å 3 , D x = 2.39 g cm −3 at 70 K; Z = 1, λ = 0.8330 (5) Å, μ = 1.78 cm −1 , F (000) = 9.503 fm; final R = 2.42, wR =…
Trichothiodystrophy (TTD) is a rare autosomal recessive disorder characterized by brittle hair with reduced sulfur content, ichthyosis, peculiar face, and mental and growth retardation. Clinical photosensitivity is present in approximately 50% of TTD patients but is not associated with an elevated frequency of cancers…
The Hamaker constants of eight different ceramic materials, 6H‐SiC, tetragonal, partially stabilized ZrO 2 (3% Y 2 O 3 ), β‐Si 3 N 4 , α‐Al 2 O 3 , Y 2 O 3 , sapphire (single‐crystal α‐Al 2 O 3 ), MgO, MgAl 2 O 4 , and fused silica, across air, water, and n ‐dodecane at room temperature and across silica at 2000 K hav…
The deformation pattern at grain boundaries and at triple junctions in polycrystalline high purity aluminium (99.999%) has been studied by electron back scattering pattern (EBSP) observations. Specimens of two different grain sizes rolled to give 5% and 30% reductions have been examined by these different EBSP scans:…
The thermoelectric effect and its systematic variation with doping level ($x$), temperature ($T$), and external magnetic field ($H$) have been investigated for crystals of double-exchange ferromagnets, ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Mn}{\mathrm{O}}_{3}$ ($0.15<~x<~0.50$). Large $T$- an…
High-performance polymers are used in applications demanding service at enhanced temperature while maintaining their structural integrity and an excellent combination of chemical, physical, and mechanical properties. Some of the important polymers in this respect are polyimides, polyamides, and polybenzazoles. However…
A Nd‐doped HfO 2 ‐Y 2 O 3 ceramic having excellent transmittance was synthesized by HIPing, using high‐purity powders (>99.99 wt%) of Y 2 O 3 , Nd 2 O 3 , and HfO 2 . The mixed powder compacts of these powders were sintered at 1650°C for 1 h under vacuum and HIPed at 1700°C for 3 h under 196 MPa of Ar. The specimen…
Localized {100} fiber textured diamond films were grown by addition of 20–200 ppm nitrogen into the gas phase during hot-filament chemical-vapor deposition (CVD). Cathodoluminescence indicates the presence of the nitrogen-vacancy system in the {100} textured diamond, whereas a blue ‘‘band A’’ luminescence is normally…
It is now well known that Si, B and OH+F are variable components of tourmaline, and yet the stereochemical details of their variation in the tourmaline structure are still not well characterized or understood. Application of the valence-sum rule of bond-valence theory to questions of short-range atomic arrangements sh…
Microstructure, cathodic polarization, and ohmic resistance on the cathode side of ‐based solid oxide fuel cells have been studied for the intermediate temperature operation range between 700 and 900°C. Starting powder characteristics, powder calcination temperature, and sintering temperature strongly influence the fi…
A ceramic‐matrix composite (CMC) that exhibits damage‐tolerant behavior without “weak” interfaces has been demonstrated. The concept relies on the heterogeneous distribution of fiber bundles within a porous matrix having homogeneous, fine porosity. It also depends on the development of residual stress from thermal exp…
The sonolytic degradation of aqueous carbon tetrachloride is investigated at a sound frequency of 20 kHz and 135 W (112.5 W cm - 2 ) of power. The observed first-order degradation rate constant in an Ar-saturated solution is 3.3 × 10 - 3 s - 1 when the initial CCl 4 concentration, [CCl 4 ] i, is 1.95 × 10 - 4 mol L -…
General Survey. Quantum Theory and Magnetism. Spin and Magnetization, Statics and Dynamics. Magnetostatics, Magnetic Domains and Magnetic Design. Survey of Magnetic Materials. Special Topics. Appendices. Indexes.
We analyse the kinetics of the transition between two variants of martensite during biaxial dead loading. The volume fraction of one martensite variant versus the applied loads exhibits an unusual hysteresis, characterized by a sensitive dependence on the amplitude of the loads and a dissipationless response at small…
The stability of the moving contact line is examined for both Newtonian and viscoelastic fluids. Two methods for relieving the contact line singularity are chosen: matching the free surface profile to a precursor film of thickness b, and introducing slip at the solid substrate. The linear stability of the Newtonian ca…
“ In situ toughened” silicon carbides, containing Al, B, and C additives, were prepared by hot pressing. Densification, phase transformations, and microstructural development were described. The microstructures, secondary phases, and grain boundaries were characterized using a range of analytical techniques including…
Highly tetrahedral, dense amorphous carbon (ta-C) films have been deposited using rf sputtering of graphite by an unbalanced magnetron with intense dc Ar-ion plating at low temperatures (&lt;70 °C). The ratio of the argon ion flux to neutral carbon flux Φi/Φn is about 5. The film density and compressive stress are…
Shape-memory behavior is the ability of certain materials to recover, on heating, apparently plastic deformation sustained below a critical temperature. Some materials have good shape-memory behavior as single crystals but little or none as polycrystals, while others display good shape-memory behavior even as polycrys…