Materials Literature
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Quasielastic light scattering (QLS) in the frequency interval 100–1000 GHz is measured in some polymers: polycarbonate, polybutadiene, polystyrene, and poly(methyl methacrylate). To describe the spectra, a model of the fast picosecond relaxation processes responsible for the QLS, which is based on the damping of the b…
Vapor-deposited amorphous water ice when warmed above the glass transition temperature (120-140 K), is a viscous liquid which exhibits a viscosity vs temperature relationship different from that of liquid water at room temperature. New studies of thin water ice films now demonstrate that viscous liquid water persists…
We have measured the dielectric relaxation of the glass-former 1-propanol for temperatures between 65 and 350 K in the frequency range 10−2 to 2⋅1010 Hz and the photon correlation spectro-scopy decays near Tg. Attributing the strong Debye-type process of 1-propanol to distinct -OH group effects leaves two faster proce…
The structure, phase transformation, and magnetic properties of mechanically alloyed (MA) samples have been studied systematically. can be formed within certain composition and temperature (from to ) ranges. Isothermal annealing of at for different lengths of time reveals that the formation of is a nucleation and grow…
Magnetic-flux-leakage (MFL) measurements are used for corrosion inspection of buried oil and gas pipelines. MFL signals are sensitive to the depth of defects, such as corrosion pits, in the pipe wall and to external stresses generated mainly by the line pressure. MFL signal variations have been studied from the inside…
The three-dimensional crystal structure of Serratia marcescens (Sm) nuclease has been refined at 1.7 A resolution to the R-factor of 17.3% and R-free of 22.2%. The final model consists of 3678 non-hydrogen atoms and 443 water molecules. The analysis of the secondary and the tertiary structures of the Sm nuclease sugge…
Useful and simple 3D crossover expressions are presented for the resistance versus temperature behaviour in highly insulating 3D films. At high temperatures, this theory extrapolates to the Mott variable-range hopping law, and at low temperatures to the Efros - Shklovskii variable-range hopping law. Good agreement is…
A high density ferroelectric memory process flow requires the integration of conducting barrier layers to connect the drain of the pass-gate transistor to the bottom electrode of the ferroelectric stack. We are studying the effect of crystallinity of the TiN/Pt barrier layer with Si wafers on the ferroelectric propert…
We show that the large electrical-field-induced strain response observed in certain polyurethane elastomers is a thin-film effect. Based on the frequency dispersion of the strain response in samples with different thicknesses and the thermally stimulated discharge current on samples with different processing condition…
Europium doped yttrium oxide (Eu:Y2O3) phosphor thin films were grown using a pulsed laser deposition (PLD) technique at varying growth conditions. The structural characterization carried out on a series of Eu:Y2O3 films grown on (100) silicon at substrate temperatures in the range of 250–600 °C and oxygen pressure in…
We calculate cohesive properties of LiF, NaF, KF, LiCl, NaCl, and KCl with ab-initio quantum chemical methods. The coupled-cluster approach is used to correct the Hartree-Fock crystal results for correlations and to systematically improve cohesive energies, lattice constants and bulk moduli. After inclusion of correla…
We report on large scale numerical simulations of fracture surfaces using random fuse networks for two very different disorders. There are some properties and exponents that are different for the two distributions, but others, notably the roughness exponents, seem universal. For the universal roughness exponent we fou…
We perform molecular dynamics simulations of friction for atomically thin Xe films sliding on Ag(111). We determine the inverse of the coefficient of friction (i.e. slip time) by direct calculation of the decay of the center of mass velocity after applying an external force, as well as from the velocity autocorrelatio…
X-ray measurements show that GeO2 and Ge nanocrystals with a radius from 25 down to 1.5 nm are formed in an oxide matrix after annealing. Under ultraviolet excitation, both types of films luminesce around 3.1 eV, with identical photoluminescence (PL) line shapes and subnanosecond PL dynamics. The strongest PL intensit…
We present an exact formulation of the physics of Barnett relaxation. Our formulation is based on a realistic kinetic model of the relaxation mechanism, which includes the alignment of the grain angular momentum in body coordinates by Barnett dissipation, disalignment by thermal fluctuations, and coupling of the angul…
In this study the microphase separation and structural organization of the hard segment domains were studied as a function of diethanolamine (DEOA) content for two series of model foams based on toluene diisocyanate (TDI) and glycerol initiated ethylene-oxide-capped propylene-oxide or glycerol initiated propylene-oxid…
Gelatin was graft copolymerized with poly(hydroxyethyl methacrylate and butyl acrylate) and subsequently crosslinked with glutaraldehyde. Fibrin of bovine origin was incorporated onto this graft copolymer and characterized for the percentage of grafting. The infrared spectroscopy, mechanical strength, and water absorp…
A novel method is used to study topological and molecular structure of different kinds of sulfur (mineral and two polymeric types). It is based on thermomechanical analysis of solid (not dissolved) polymer. It was found that a deep difference in their molecular weight distributions and in their crystallinity degrees e…
Two- and three-layer composite latex particles were used to prepare rubber-toughened poly(methyl methacrylate) (RT-PMMA). The interfacial thicknesses of the multi-layered particles were varied by using different emulsion polymerization synthesis techniques. The resulting interphases were previously characterized by 13…
The effect of process parameters on the conversion, P, and current efficiency, η, for the aqueous electropolymerization of pyrrole on low-carbon steel has been investigated. The amount of polypyrrole coatings formed on steel, Wp, increased with the charge passed, Q, and the initial pyrrole concentration [M], but was u…