Materials Literature
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We perform ab initio plane wave supercell density functional calculations on three candidate models of the (3 x 2) reconstruction of the beta-SiC(001) surface. We find that the two-adlayer asymmetric-dimer model (TAADM) is unambiguously favored for all reasonable values of Si chemical potential. We then use structures…
Recent high transverse field muon spin relaxation (TF-uSR) experiments performed on Bi2212 single crystals show that the phase parameter extracted from individual histogram, an indication of the angle between the muon's initial polarization direction and the detector direction, is temperature dependent. This phase shi…
This paper gives an outline of testing carried out in conjunction with Electroimpact to support the introduction of the A319/A320/A321 and A340-500/600 Panel Assembly Cells in Broughton, UK. Testing compared the percussion insert/EMR swaging of lockbolts with existing hydraulic installation methods. Tests included pre…
The electron-phonon coupling for Cr 3+ in different oxide host lattices (MgO, α-Al 2 O 3 and LaAlO 3 ) was probed by performing temperature dependent line broadening measurements for zero-phonon emission lines of single ions and exchange coupled pairs. No differences in electron-phonon coupling were found comparing th…
Aqueous gelatin slowly cooled from the sol state (60 °C) to different temperatures around the gel point has been investigated using dynamic light scattering. Three modes of correlation decay have been observed and their dependence on scattering vector ( q ), concentration ( c ), and temperature interpreted in the ligh…
A new manganese oxide, Ba 4 Ca 1 - x Mn 3+ x O 12 - δ, closely related to the hexagonal perovskite family has been synthesized. It crystallizes in the P 6̄ m 2 space group with a = 5.8003(3) Å and c = 38.958(1) Å. This structure derives from the rare hexagonal 16L polytype and exhibits ordered oxygen deficient vacanci…
Introduction................................................................................................................4 Water Activity ............................................................................................................5
Spectroelectrochemical techniques have been used to study doping-induced reactions in conjugated polymers. Here, we report results on reduction reactions (n-doping) of the conjugated ladder polymer polybenzimidazobenzophenanthroline (BBL). The spectra are recorded in situ during applied potential in a three-electrode…
The properties of dipole-allowed and -forbidden (quadrupole) transitions in an atom placed near an ideally conducting cylinder are considered. Explicit analytical expressions for transition rates for different orientations of dipole and quadrupole are found. It is shown that the decay rates of dipole and quadrupole tr…
Neutral phosphorus-containing dendrimers with aldehyde groups at the periphery have been analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) up to generation four. Although the expected quasi-molecular ion is generally observed, the mass spectral pattern, presence…
The 48-h hydrothermal crystallization of a magnesium silicate clay called hectorite has been investigated in detail. Tetraethylammonium (TEA) ions are used to aid crystallization and become incorporated as the exchange cations within the interlayers. Data from small-angle X-ray scattering (SAXS) using aliquots ex situ…
The effect of density (relative densities 0.33 to 0.90) on the impact behavior of microcellular polycarbonate (PC) was investigated. Cell size and foaming gas content were also considered. Flexed-beam Izod impact tests were conducted and the impact strength of these foams appears to be a strong function of both densit…
The compounds of formula {Ln 2 [Ni(opba)] 3 }·S (opba being o -phenelynebis(oxamato), Ln lanthanide III ions, and S solvents molecules) have been structurally and magnetically characterized for Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, and Er. These compounds crystallize poorly, and structural information has been obtained…
Horseradish peroxidase-mediated polymerization of styrene at ambient temperature is reported. Molecular weight and yield of polystyrene were influenced by solvent, concentration of hydrogen peroxide, and initiator (beta-diketones, coumarin). THF:H2O (v/v) and hydrogen peroxide (0.082 mol/L) provided maximum yield of p…
The effects of high-speed melt spinning and spin drawing on the structure and resulting properties of bacterial generated poly(3-hydroxybutyrate) (PHB) fibers were investigated. The fibers were characterized by their degree of crystallinity by differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WA…
The basic layered hydrotalcites have been used as catalysts for the epoxidation of alpha,beta-unsaturated ketones in heterogeneous reaction media using hydrogen peroxide as an oxidant. A wide variety of alpha,beta-unsaturated ketones were oxidized to the corresponding epoxyketones in excellent yields under mild reacti…
The surface of oxygen-plasma-treated polystyrene (PSox) was investigated using X-ray photoelectron spectroscopy (XPS), streaming potential measurements and a dynamic study of the wetting properties at different pH (Wilhelmy plate method). The PSox surface is functionalized with various oxygen-containing groups, includ…
A critical review and experimental comparison between different techniques for the determination of interfacial tension are presented for a model polymer pair. Five experimental methods were applied to measure the interfacial tension for the model pair of polystyrene (PS) and polyamide-6 (PA-6) at the same temperature…
Single crystals of the quasi-two-dimensional organic type II superconductor, κ-(BEDT-TTF) 2 Cu(NCS) 2 , have been studied in magnetic fields of up to 33 T and at temperatures between 0.5 K and 11 K using a compact differential susceptometer. When the magnetic field lies precisely in the quasi-two-dimensional planes of…
Under pressure cesium undergoes a transition from a high-pressure fcc phase (Cs-II) to a collapsed fcc phase (Cs-III) near 4.2GPa. At 4.4GPa there follows a transition to the tetragonal Cs-IV phase. In order to investigate the lattice vibrations in the fcc phase and seek a possible dynamical instability of the lattice…