Materials Literature
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A discussion is given of various models for the Verwey transition in Fe3O4and Ti4O7, and its apparent absence in Sm3S4. In allsystems there is evidence for polaron formation, and for bipolarons in the first two. It is suggested that, in spite of polaron formation, in low-temperature Fe3O4 there must be considerable ov…
A detailed investigation on the thermal expansion, magnetic properties and electrical resistance of rapidly quenched amorphous (Fe,Co,Ni)-Zr alloys has been undertaken. Magnetic properties of these alloys are reported separately in this conference. The thermal expansion curves exhibit typical invar characteristics bel…
Summary Arsenohauchecornite, Ni 9 BiAsS 8 , and tellurohauchecornite, Ni 9 BiTeS 8 from the Sudbury area, Ontario, are now recognized as distinct mineral species in the Hauchecornite Group and not as varieties as described previously. Descriptions of these two minerals are given, summarized from Gait and Harris (1972).
Summary Twenty surface soils from four main Soil Groups in Malawi and their sub‐soils were divided into three groups based on cation exchange capacity (group I, CEC < 50; group II, 50–100; and group III > 100μeq g –1 ). In each soil group the maximum amounts of K removed by successive extraction with 0.005 M CaC…
The wide obtainable range of mechanical compliance encourages the application of helical magnetostrictive springs in force and pressure transducers as well as for direct displacement sensing. In the usual mode of operation, an alternating current is conducted through the magnetostrictive wire, and an output signal (re…
Summary The name hauchecornite has been applied in the literature to a group of minerals with similar crystal structures and the general formula (Ni,Co,Fe) 9 AB S 8 , where A and B are As, Sb, Bi, and Te in two nonequivalent structural sites. A classification of the group is proposed based on the relative abundance of…
Simple binary alkali borate glasses of differing alkali content (alkali = Li, Na, or K) containing sulfur were prepared and their absorption spectra were measured in the range of 200 to 700 nm. The absorption bands obtained were used to determine the stable states of sulfur in these glasses by directly comparing them…
Surfaces of Cu–Be (2%) dynodes activated at various conditions were studied. The mechanism of formation of the BeO layer was studied by means of surface analysis with ESCA, SEM, and AES. Peaks of oxidized Be, O, and a little C were detected but Cu was not found at all in the ESCA and AES spectra of surface products pr…
The inhibition of corrosion of 1018 mild steel in sulfuric acid by thiourea and its derivatives has been investigated. The effectiveness of inhibition is rationalized through the use of two molecular parameters, viz., the electron density associated with the sulfur atom, and the topology of each thiourea molecule. The…
Abstract The thermal decomposition of two isocyanurates and an MDI‐based polycarbodiimide was studied by high temperature infrared spectroscopy, thermogravimetric analysis and differential thermal analysis. The results (confirmed by large scale pyrolysis) show that the s ‐triazine moiety decomposes above 400°C to gene…
"Optical properties of magnetite Fe3O4 ." Philosophical Magazine B, 42(3), pp. 431–432
Abstract BaCdGeS 4 wurde erstmals dargestellt und röntgenographisch untersucht. Es kristallisiert isotyp mit BaCdSnS 4 [1] in der Raumgruppe C −Fdd2 (Nr. 43). Gitterkonstanten: a = 2169, b = 2125, c = 1278 pm. Die charakteristisch verknüpften „Doppeltetraeder”︁ mit gemeinsamen Kanten bilden das strukturbestimmende Tet…
Raman measurements of intermolecular vibrational frequencies, differential scanning calorimetry, and ESR measurements of triplet excitons are reported for crystalline anthracene–tracyanobenzene and various deuterated analogs. Deuteration of all the α- or all β-anthracene positions lowers the temperature of the order–d…
Summary The chemical stabilities of mendipite, Pb 3 O 2 Cl 2 , diaboleïte, Pb 2 CuCl 2 (OH) 4 , chloroxiphite, Pb 3 CuCl 2 O 2 (OH) 2 , and cumengéite, Pb 19 Cu 24 Cl 42 (OH) 44 , have been determined in aqueous solution at 298.2 K. Values of standard Gibbs free energy of formation, ΔG f ° , for the four minerals are…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic study of the pyrolysis of neopentane during its induction periodPhilip D. Pacey and Jayantha H. WimalasenaCite this: J. Phys. Chem. 1980, 84, 18, 2221–2225Publication Date (Print):September 1, 1980Publication History Published online1 May 2002Published inissue 1 Sept…
ABSTRACT Frustules of a clonal culture of Melosira roeseana Rabenh. were examined with light and scanning electron microscopy. Vegetative valves in the post‐auxospore (full size) stage exhibit a larger width/length ratio than those in the pre‐auxospore (size‐reduced) stage. Cells form chains by linking spines of adjac…
Synopsis Hydrobasaluminite and basaluminite, two hydrated basic aluminium sulphate minerals have been found in the weathering zone of the Oxford Clay at Crook Hill Brickyard, Chickerell, near Weymouth, Dorset. Hydrobasaluminite occurs as a reaction rim surrounding carbonate concretions, and is believed to have resulte…
Abstract The glass transition temperature T g of an elastomer is of great importance with regard to its utilization since at this temperature and below, the material can no longer exhibit rubberlike behavior. In the present study, networks were prepared from atactic poly(vinyl acetate) and poly(isobutyl methacrylate),…
Abstract X‐ray diffraction techniques have been used to investigate the orientation under stress of collagen fibres in pig's descending aortic wall. The variation of the limit value of the incremental modulus as a function of the collagen content seems to suggest that the extra amount of collagen going from the aortic…
A study was conducted which examined the influence of electropolishing on the corrosion resistance of a cold rolled 316L stainless steel. Test specimens were surface prepared to a final mechanical finish of wetted 600 grit SiC paper, prior to electropolishing. An o-H3PO4/Glycerol/H2O electropolishing solution was empl…