Materials Literature
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X-Ray structure determination of K8[Mo36O112(H2O)16]·36H2O which crystallises from medium-acidified aqueous molybdate solutions (mole ratio added [H+]: added [MoO42–], ca. 1·8–2·0) shows that the largest isopolyanion known to date reflects the conditions of its formation and contains structural features typical of bot…
In the μ-carbido complex (4), obtained as shown below, the tin atom is linked to the rhenium atoms via a carbide carbon atom which bonds like a carbyne to the rhenium (TPP stands for tetraphenylporphyrin). An impression of the spatial arrangement of the complexes of type (3), which are formed at only slightly higher t…
Abstract FeNbO 4 wird in zwei Modifikationen ((A) Wolframit‐ und (B) AlNbO 4 ‐Typ) in einkristalliner Form dargestellt. Röntgenographische Untersuchungen von (A) und (B) ergaben: (A) a = 499,2, b = 560,7, c = 463,7 pm, β = 90,06°; Raumgruppe C P2/a. (B) a = 1230,8, b = 377,1, c = 656,9 pm, β = 107,6°; Raumgruppe C C…
The pretransitional behaviour of 12CB which exhibits a direct isotropic to smectic A phase transition has been studied by light scattering as a function of temperature in the isotropic phase. This behaviour has been examined in terms of the Landau - de Gennes model and compared with that observed for the direct isotro…
We study the stability of a Poiseuille flow in a planar nematic. We extend the analysis given in ref. [5] to take into account periodic distortions of the director. Several different approaches are employed : simplified models, Galerkin method, or numerical simulation. Our results allow one to interpret experimental f…
The room-temperature crystal structure as well as low-temperature magnetic studies which include heat-capacity, proton-resonance, and magnetic-susceptibility experiments are reported for Mn${(\mathrm{SCN})}_{2}$${({\mathrm{C}}_{2}{\mathrm{H}}_{5}\mathrm{O}\mathrm{H})}_{2}$. The compound belongs to the space group $\fr…
Under the condition postulated for a loss-of-coolant accident (LOCA), Zircaloy-4 fuel cladding may experience a temperature transient during which it absorbs an appreciable amount of oxygen from the coolant. Theoretical models for predicting cladding behavior during loss-of-coolant (LOC) are being developed, but until…
Electrical conductivity and the ionic and electronic transference numbers were determined for two types of unintentionally doped single crystalline sapphire for current directions perpendicular to the r plane (1102). One was acceptor dominated and the other was initially donor (H i x ) dominated, changing to acceptor…
The microstructure of the built-up edges of a number of alloys has been examined using both optical and electron microscopy. The built-up edges of the two ferrific steels examined showed that these were significantly different to those formed in austenitic stainless steel and Cu–40Zn brass. The built-up edge deformati…
Typical Bs type phase solubility diagrams were obtained for α-and β-cyclodextrins (α-CyD and β-CyD) with methyl cinnamate, ethyl cinnamate, and cinnamaldehyde in water at 25°. Solid complexes for α-and β-CyDs with three guest molecules were obtained and their molar ratios were found to be 2 : 1 (α-CyD/guest molecule)…
The existence of compounds between Si 3 N 4 ‐CeO 2 and Si 3 N 4 ‐Ce 2 O 3 was investigated for firing temperatures of 1600° to 1700°C. The two new monoclinic compounds found were Ce 2 O 3 ·2Si 3 N 4 with lattice parameters a = 16.288, b = 4.848, and c =7.853 Å and β=91.54° and Ce 4 Si 2 O 7 N 2 with lattice parameters…
Abstract A static platelet adhesion test using whole human blood was employed to assess the affinity of various bare polymer (sulfonated polystyrene, acetal resin, Teflon FEP, polystyrene) surfaces as well as various surfaces of glass and polymers that were coated with plasma proteins. Platelet adhesion to the bare po…
In this paper, an evaluation of the methods of finite elements and finite differences, as applied to nonlinear magnetic field problems in electrical machines, is presented. The evaluation covers the aspects of effectiveness, numerical accuracy, modeling implementation considerations as well as computer storage and exe…
The phase relations in the system HfO 2 ‐Sm 2 O 3 were studied by high‐temperature and room‐temperature X‐ray diffraction. The areas of existence of the solid solutions based on HfO 2 , Sm 2 Hf 2 O 7 , and Sm 2 O 3 were determined using the lattice parameter method. Also, the influence of small additions of Sm 2 O 3 o…
Emission and excitation spectra for Ce 3+ in CaS have been observed at 75 K. They exhibit sharp phonon replicas due to pseudolocalized lattice vibrations. The observed frequencies of the pseudolocalized vibrations are 293 and 209 cm -1 in the emission spectra, and 282 and 206 cm -1 in the excitation spectra. Peak posi…
Abstract Graft polymerizations of vinyl acetate onto granular corn starch were initiated by cobalt‐60 irradiation of starch‐monomer‐water mixtures, and ungrafted poly(vinylacetate) was separated from the graft copolymer by benzene extraction. Conversions of monomer to polymer were quantitative at a radiation dose of 1…
Abstract Die ternären Selenide Rb 3 Cu 8 Se 6 und Cs 3 Cu 8 Se 6 konnten durch Umsetzungen von Alkalimetallcarbonaten mit Kupfer und Selen in der Schmelze synthetisiert werden. Röntgenbeugungsuntersuchungen an Einkristallen führten zur Struktur der isotypen Verbindungen. Die monoklinen Elementarzellen enthalten zwei F…
Polygonal defect arrays in lipid liquid crystals prepared from dipalmitoyl-, dimyristoyl-, and dilaurylphosphatidylcholine with various concentrations of water have been observed and characterized using optical microscopy. These arrays appear similar to the polygonal arrays previously observed in thermotropic smectic…
Abstract The most important techniques of those currently used in Home Office forensic science laboratories for the analysis of fiber dyestuffs are thin-layer chromatography and visible absorption spectroscopy of dye solutions. To obtain useful discrimination 20 to 50 ng of each dye component must be extracted. In mos…
Mono and diesters of itaconic acid have been pi'epared using linear , branched or cyclic alkane structures . These have been homo and copolymerized to produce a wide range of polymers with differing properties. These range from polyacids to polydiesters to ionomeric structures. Their physical behaviour has been examin…