Materials Literature
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Cationic (LEWATIT S100) and anionic ion exchangers (LEWATIT M500MB) were thermally decomposed in amounts of 15–60 μg in a foil pulse pyrolyzer. The gaseous products were gas-chromatographically separated and identified by mass spectrometry. Cationic resins release mainly sulfur dioxide and benzene at temperatures up t…
Abstract A series of new polyamides and copolyamides containing aromatic sulfone ether linkages was synthesized from 4,4′‐[sulfonyl‐bis(4,1‐phenyleneoxy‐3‐pentadecyl)]bisphenylamine (SPPBA) and isophthaloyl chloride (IPC), terephthaloyl chloride (TPC), bis(4‐chlorocarbonylphenyl)dimethylsilane (DMSC) and bis(4‐chloroc…
Abstract The synthesis of functionalized unsymmetrically substituted tetrathiafulvalenes 1, 2 and 3, 4 (see scheme in the introduction) was described. Two routes were used. A cross‐coupling preparation from appropriate 1,3‐dithiolium salts which offered poor yields and a WITTIG‐HORNER type reaction which was studied i…
Abstract A series of cellulose–polysilicic acid hybrid fibres with 15–35% silica contents were spun and their flammabilities were assessed by the LOI oxygen index test. Also, the rate of heat release and toxicities of fumes evolved during the combustion process for hybrid fibre with 33% SiO 2 loading was obtained usin…
The continuum equations of Leslie et al. [1] for smectic C, and the extension of this theory for chiral smectic C* [2], are applied to problems involving simple planar layer configurations which accommodate uniform layer thickness constraints. The chiral smectic C*M and non-chiral smectic CM [3] are considered as eith…
The use of ozone depleting, so-called hard CFCs as blowing agents for rigid PU foams is presently experiencing considerable political and legislative pressure, to such an extent that a complete ban of these substances is expected within the foreseeable future. Consequently, there exists an urgent need for new thermal…
The dc electrical conductivity of the ternary glasses [81 mol, TeO2-19 mol P2O5]0.95 [RnOm]0.05 (R=La, Ce, Pr, Nd, Sm, and Yb) have been measured in the temperature range 50–300 °C. The electrical conductivity data have been examined and discussed on the basis of small polaron hopping conduction theory for the purpose…
In the present article, we review the recent neutron scattering studies on the anomalous behaviours found in the premartensitic bcc-based metals and alloys, i.e. alkali metals, group-IV metals, β-phase alloys, Ni-base alloys and others such as T1 and group-III metals. Lattice dynamical anomalies appearing on the [110]…
At high temperatures Sr 2 MnO 4-y crystallizes in the K 2 NiF 4 structure with anion defects. X -ray structure determination in space group I 4/m m m (No. 139) with a = 380.58(3), c = 1253.19(11) pm reveals the composition Sr 2 MnO 3.84±0.05 for a single crystal prepared under argon at 1510 °C. The oxygen deficiency i…
The ionic conductivities, σi, of La0.6Sr0.4Co1–yNiyO3(y= 0, 0.02) have been measured by the a.c. four-probe method with electron-blocking electrodes, and compared with diffusivity of oxygen from the oxygen isotopic-exchange reaction. The ionic conductivities estimated from both methods are similar. σi; values for the…
Unfinished wood siding was exposed outdoors for 1 to 16 weeks. Following this preweathering, the specimens were finished with a variety of film-forming finishes (paints or solid-color stains) and placed outdoors again (weathered) for several years. The finished specimens were evaluated annually to determine the effect…
Mechanical properties of α Ti are strongly influenced by texture and oxygen content. The effect of texture and oxygen content on the deformation behavior was investigated using three kinds of textured Ti sheets containing 0.05, 0.1, 0.2 and 0.4 mass%O. Especially, we paid attention to deformation twinning and 〈c+a〉 sl…
espanolSe ha preparado aluminato monocalcico por la via sol-gel y por el metodo Pechini. Siguiendo este ultimo metodo se obtuvo CaO AI2O3 (CA) ortorrombico a 900**C sin formacion de fases intermedias, mientras que la fase ortorrombica de CA cristalizo junto a otras fases cuando el gel se calcino a l.OOO^'C. Cuando los…
The authors point out that aerospace electronic and power systems demand increasing levels of safety, efficiency and power delivery because of the severe effects from long term operation in the space environment, often without any manned operation or maintenance. Consequently, the design requirements place more emphas…
A study has been made of the feasibility of applying optical fibre sensing technology to acoustic monitoring of partial discharges within gas insulated substations (GIS). A test rig has been constructed to simulate a section of GIS in which acoustic sources could be placed. This has been used to test the optical syste…
One of the problems with which we meet when we use the commercially available rare earth metals is the presence of interstitial impurity elements, particularly oxygen. Its amount often exceeds a thousand mass ppm. According to the thermodynamical values for the rare earth-oxygen system, some of the rare earth metals s…
Radiation damage in lithium orthosilicate (Li4SiO4) and Al-doped Li4SiO4 (Li3.7Al0.1SiO4) irradiated with oxygen ions was studied with ionic conductivity measurements, Raman spectroscopy, Fourier transform infrared photo-acoustic spectroscopy (FT-IR PAS) and transmission electron microscopy. It was seen from the ionic…
We have measured the dielectric constants of 6CHBT. The results from studies of various alignments and thicknesses measured under different electric and magnetic fields are presented. We discuss how the dielectric properties depend on boundary conditions, sample thickness and the magnitudes of electric and magnetic fi…
Low temperature (T = 10 K) luminescence decay curves of A2SeCl6 (A = Rb, Cs) are recorded which follow optical excitation at λexc = 458 nm applying different pulse lengths between 90 ns and 100 μs. For short excitation pulses a biexponential decay is observed, for pulse widths t exc > 10 μs a single exponential decay…
A TEM observation and an EDX analysis were carried out on interfaces between Ag-Cu-2wt% Ti alloy and three types of SiC containing B and C, BeO or Al2O3 as additives. They were brazed at temperatures of 850° or 950°C for 30 min. Interfacial structures of the specimens joined at 850°C were SiC (containing B+C)/TiC/Ti5S…