Materials Literature
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The release of Ca 2+ and OH” from tricalcium silicate into the aqueous phase was monitored over the first few hours. The solution becomes supersaturated with respect to pure calcium hydroxide with the maximum activity product being about 3.5 times greater than the solubility product. Evidence is presented in support o…
This book contains the papers given at a conference on the use of ferritic steels as reactor materials in nuclear and thermonuclear power plants. Topics considered at the conference included light water reactors (application and experience), liquid metal cooled fast breeder reactors, fusion reactor systems, non-nuclea…
Four new series of ferroelectric liquid crystals (p-alkoxybenzylidene-p′-amino-1p″-methylbutylcinnamate, p-alkoxybenzylidene-p′-amino-1p″-methylpropyl-cinnamate, o-hydroxy-p-alkoxybenzylidene-p′-amino-2p″-methylbutylcinnamate and o-hydroxy-p-alkoxybenzylidene-p′-amino-1p″-methylpropylcinnamate) have been synthesized.…
Abstract Photomicrographys of concentrated lyotropic hydroxypropylcellulose solutions confirm the cholesteric nature of the anisotropic phases in acetic acid and water. They reveal the existence of biphasic separation. Typical liquid‐crystal solvent‐dependent textures are observed. The behavior of liquid‐crystalline p…
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Mouse mammary sarcoma cells, line EMT6/Ro, were exposed for 1 min to 1 MHz continuous wave ultrasound over a range of intensities from 0.5 to 30 W/cm2 (spatial peak). The presence of thymine base damage (TBD) products of the 5,6-dihydroxydihydrothymine type was determined by an alkali degradation assay. Production of…
The structure of wermlandite, (Mg7(Alo.57Feo.43h(OH)ls)2+ ((CaO.6'Mgo.4) (S04h(H20)u)2- has been determined and refined to an R value of 7.2 % based on 779 symmetry-independent reflections, of which 224 are unobserved (weighted R=6.1%). The cell dimensions are a=b=9.303(3), c=22.57(1) A, the space group is pjc1 with Z…
The measurements of the bend (k33) and splay (k 11) elastic constants and the amplitude of the smectic-like local ordering (obtained using X-ray diffraction techniques), have been made for a wide range of nematogens. The results reveal a strong correlation between k33/k11 and the strength of the smectic-like local ord…
The dependence of the hot ductility of Al-Mg solid solution on temperature, strain rate, grain size and solute content has been examined in detail by use of tensile test. At a constant strain rate, a ductility (reduction of area) versus temperature curve showed a remarkable trough. With increase in the strain rate, th…
The effects of grinding and drying (removal of water of crystallization) processes on the solidstate stability of ampicillin trihydrate were studied. The ground samples became more unstable as the grinding time increased. This phenomenon is considered to be due to a greater freedom of movement of water molecules, whic…
The thermal transition of carbamazepine polymorphic forms (forms I, II, III) in the solid state was investigated by X-ray powder diffractometry. From the kinetic analysis according to the method of Hancock-Sharp, it appears that the transition of form I to form III follows the mechanism of random nucleation and two-di…
Abstract Thermodynamics of K exchange were investigated in Ca‐saturated samples from the Ap horizon of an Evesboro soil from Delaware. At 283 and 298 K the selectivity curves (ln k v vs. X̄ K ) showed preference for K at low values of N K (mole fraction of K in solution) and for Ca at higher values. This selectivity r…
Reaction of protoporphyrin IX dimethyl ester with strongly activated dienophiles causes a Diels–Alder reaction to occur with the porphyrin periphery; elimination of the angular methyl group from these adducts gives monobenzoporphyrins.
(1984). Solid State Reactions - Theoretical and Experimental Aspects. Drug Development and Industrial Pharmacy: Vol. 10, No. 8-9, pp. 1175-1276.
Various microscopic surface structures of silica–alumina and silica–magnesia which can generate Brønsted acidity are discussed via molecular-orbital calculations using cluster models, together with indices for Brønsted acidity. Mechanisms explaining the origin of the Brønsted acidity of the solid surface are proposed…
The existence of isoelectric variants of bovine brain and human placental choline acetyltransferase was confirmed by chromatofocusing. The identification of molecular weight variants (bovine brain, Mr = 68,000 and 63,000; human placental, Mr = 66,000 and 64,000) was also demonstrated using sodium dodecyl sulfate-polya…
On presente des donnees de spectroscopie de photoelectrons induits par RX sur des verres de compositions 20Na 2 O-x R 2 O 3 -(80-x)SiO 2 et 20Na 2 O-xTlO-(80-x)SiO 2 (x=0-20 mol.%; R=Ga, In, Sc, Y ou La) 2 . Du thallium et des ions trivalents plus gros, In 3+ , Sc 3+ , Y 3+ et La 3+ sont incorpores dans les verres en…
Introductory investigations performed in order to make quantitative electron-probe microanalysis of very light elements such as boron, carbon, nitrogen or oxygen possible are described. The practical problems encountered in this kind of work are discussed in detail and, where possible, solutions are proposed. It is sh…
Crystal structure / Phase transition / Tricalcium silicate Abstract. Crystals of tricalcium silicate having a monoclinic superstructure transformed into a rhombohedral structure when they were heated at 1200 °C with gas flame: a=7.135(6) A, c=25.586(15) A, space group R3m, and contents of 9 x Ca2,9sSio,9sAlo,o40s.The…
For valves of the same diameter, type material of Stephanodiscus rotula, observed with light and scanning electron microscopy, has more total spines, more central strutted processes, and narrower mantles than does S. niagarae. However, these characters covary with diameter and with one another within each species. Thu…