Materials Literature
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One flask synthesis of dithienylmethane and difurylmethane is reported. The reaction of aldehydes with excess furan or thiophene affords the meso-phenyldithienylmethane (DTM) and meso-phenyldifurylmethane (DFM), respectively. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. An acyl group is sele…
Hydrogen is considered one of the major problems for ferritic and martensitic steel structures in future fusion reactors. In contrast to hydrogen from other sources, hydrogen produced by nuclear transmutations cannot be kept away by barriers but must be drained off through the surfaces. An upper limit of the diffusion…
The microstructure and dielectric properties of A‐site‐excess and stoichiometric‐composition strontium calcium titanate ((Sr,Ca)TiO 3 ) ceramics were investigated in the present study. Ruddlesden‐Popper‐type planar faults in A‐site‐excess specimens were observed using high‐resolution scanning transmission electron mic…
Morphology changes induced in polycrystalline silver catalysts as a result of heating in either oxygen, water or oxygen–methanol atmospheres have been investigated by environmental scanning electron microscopy (ESEM), FT-Raman spectroscopy and temperature programmed desorption (TPD). The silver catalyst of interest co…
The redox potential of heme undecapeptide from cytochrome c (microperoxidase 11) in aqueous sodium dodecyl sulfate (sds), hexadecyltrimethylammonium bromide, and Triton X-100 surfactant micelles varied from +2 mV at pH 3.0 to –222 mV at pH 9.0. The potentials at pH 7.0 were –114, –122, and –166 mV vs. the normal hydro…
This paper deals with application of stochastic procedures for the analysis of PDHD (partial discharge height distributions) detected during life of insulation systems. Experiments of accelerated aging under electrical stress were carried out on both an artificial flat cavity and a 23 kV epoxy-resin insulator, where P…
The 205Tl NMR and UV/VIS spectral changes associated with the hydrolysis of thallium(I) have been employed to investigate hydroxide-sensitive equilibria in highly concentrated alkaline aluminate solutions {0.1 M < [Al(III)]T < 2.6 M; 0.15 M < [NaOH]T < 4.0 M} in an ionic medium of 8 M Na(ClO4) at 25 °C. Spectroscopic…
A synthetic route to a tetrathiafulvalene (TTF) derived aspartic acid derivative 18, with suitable orthogonal protecting groups has been developed. The aspartic acid derivative 18 can be used in the synthesis of peptides, as exemplified by the synthesis of di-, tri- and tetra-peptides 21–23. Preliminary electrochemica…
Thermal initiation of a mix of metal superoxide (MO2 , M=Sr, Ba), iron and iron powder in air induces a self propagating reaction with velocity 0.5 mm s–1 and the formation of predominantly MFe12O19 . Heating the mixture to 1150 °C for 2 h produces pure crystalline MFe12O19 . The ferrites were characterised by X-ray p…
The paper describes the new phenomenon called Ion-Exchange Isothermal Supersaturahon (IXISS). This effect is observed for a number of ion-exchange systems, where frontal or reverse frontal separation is accompanied by the formation of stable supersaturated solutions of slightly soluble substances in the interstitial s…
KNbO3 ceramics were sintered at 1263K thanks to a LiF additive. The ferroelectric-paraelectric transition is of first order and occurs at T c∼670K. A dielectric study in a large frequency range (102-109Hz) shows: –a strong frequency dispersion of the permittivities at low frequency for T > 500 K which comes mainly fro…
New kinetic measurements for the CH3O + NO reaction have been performed using two different techniques. The discharge flow (DF) technique has been used to investigate the 0.5–5 Torr and 248–473 K pressure and temperature ranges and pulsed laser photolysis (PLP) has been used for the 30–500 Torr and 284–364 K ranges. T…
Infrared spectra are reported of 12 CO and 12 CO/ 13 CO mixtures adsorbed on colloidal platinum with a mean particle size of 15 Å, stabilized in liquid dispersion by polyvinylpyrrolidone. A shift to higher frequency with increasing coverage of 12 CO is observed in the high-frequency (on-top) CO band, and for 12 CO/ 13…
Synthetic phyllosilicates, with nickel replacing the magnesium atoms, have been prepared under autogenous pressures at 220 °C. Both 1:1 phyllosilicate, having interlayer spacing of 7 Å, and 2:1 phyllosilicate with 9.4 Å spacing were obtained depending on the metal to silicon ratio. The latter was also expanded to 13.2…
Abstract Impact cushioning and deformation of flexible open‐cell polyester polyurethane (PU) foams were studied as a function of specimen geometry, including the incorporation of controlled voids. It was shown that cushioning behavior is dependent on sample geometry, which was in trun due to a complex balance of air c…
Opto-thermal transient emission radiometry (OTTER) is a novel infrared remote sensing technology that can be used for water distribution within stratum corneum measurements. Comparing with other skin water content measurement techniques, OTTER has the advantages of non-contact, non-destructive, spectroscopic in nature…
The use of magnesium is closely associated with the history of the Volkswagen company. It reached a high point in 1971 of 42,000 t a year (engine block and gearbox housing, various small components) primarily for production of the air-cooled models (Beetle, Transporter). That represented approximately 20 kg of magnesi…
Abstract The use of adhesive tapes, tabs and liquids is a simple and cost-effective method for sampling gunshot residues and other trace or particulate materials prior to analysis in a scanning electron microscope (SEM). The adhesive material is placed directly onto a standard stub (specimen mount) used in scanning el…
An experimental investigation of the thermomechanical behaviour of pitch and resin bonded magnesia-carbon refractory materials has been carried out within the temperature range 20-1500°C by tension, compression, and three point bend tests. At room temperature, both types of material exhibited a non-linear, quasi britt…
Condensation of pyrrole and benzaldehyde was carried out in isooctane or cyclohexane in the presence of MCM-41, HY (Si/Al 15) and CoY (Si/Al 2.6). In all cases, formation of tetraphenylporphyrin (TPP) was observed in the organic solutions, even after dissolving with hydrofluoric acid the resulting MCM-41 solid employe…