Some characteristic behavior of mixed spin-1/2 and spin-1 Ising nano-tube

The magnetization of a cylindrical Ising nano-tube is investigated by the use of the effective field theory with correlations. The effects of the crystal field couplings at the surface shell to the order parameters, susceptibility, internal energy, specific heat and free energy are investigated. Some characteristic phenomena are examined in the thermal variations, depending on crystal field term. Moreover, tricritical and critical points are found on the (D/J,kT/J) plane, where D/J and kT/J are reduced crystal-field and temperature, respectively.     

Physico-chemical and Thermal Characteristics of Lime-silica Fume Pastes

Five lime-silica fume pastes were investigated using initial CaO/SiO₂ molar ratios of 0.80, 1.0, 1.30, 1.70 and 2.0. The kinetics and mechanism of hydration interaction between lime and silica fume were studied on the basis of the phase composition and the physical state of the formed hydration products. The developed strength could be related to the lime content of the lime-silica mixture and the formed hydrates. This revised version was published online in August 2006 with corrections to the Cover Date.     

Interfacial Interactions and Properties of Polyethylene‐Layered Silicate Nanocomposites

Summary: Organically modified montmorillonites (OMs), carrying alkyl chains, phenyl groups, or a combination of both, were prepared and compounded with polyethylene. The oxygen permeability coefficients and tensile properties of the nanocomposites were correlated to the exfoliation of the OMs. Partial exfoliation was achieved, although no intercalation was observed. Aromatic moieties attached to the clay surface led to a stronger interaction between the OM layers and less exfoliation.

Transmission electron micrograph of a 2.8 vol.‐% dioctadecyldimethylammonium nanocomposite. The dark lines are cross sections of aluminosilicate layers.     

PHYTOCHROME MEDIATED CAROTENOID SYNTHESIS IN THE FUNGUS VERTICILLIUM AGARZCZNUM

Abstract— Ten minutes of red irradiation (R) increased carotenogenesis in Verticillium agoricinum and this effect was reversed by 10min of far-red (FR) irradiation indicating that phytochrome is involved. A far-red minus red difference spectrum of a crude extract shows a peak at 670 nm and a dip at 750 nm wavelength, values slightly larger than higher plant phytochrome. indicating the presence of phytochrome.     

Aliphatic Liquid Crystals with Positive Dielectric Anisotropy

Cyanothyl-subsituted cylohexyl cyclohexanoates, bi(cyclohexanes) and phenyl cyclohexanes were synthisized. Their mesmorphic behaviour is compared to that of the corresponding cyano derivatives. (Cyanoethyl)cyclohexyl cyclohenxanoates show mesmorphic properties in contrast to the corresponding cyano derivative. Separation of the cyano substituent from the rigid core of an anisotropic aliphatic compound by methylene groups enhances the thermodynamic stability of the mesophase. In aromatic compound, the cyanoethyl group leads to lower clearing points. These phenomena are attributed to teh influence of steric effects on the packing density and to the dependence of the clearing point on molecular association.     

Shear viscosity of hydrogen and helium fluids at extended regions of temperatures and pressures

Shear viscosities of hydrogen (H₂) and helium (He) fluids are investigated at extended regions of temperature and pressure using an improved equation of state, in which the the long-range attractive forces are incorporated into the formalism via the double Yukawa (DY) potential fitted to the empirical H₂ and He potentials. Quantum effects, which become paramount at low temperatures, are taken into account through a first-order quantum correction based on the Wigner–kirkwood expansion. The dimerization of H₂ is treated as a hard convex body for which an equation of state can be derived based on the scaled particle theory.     

Complexes of N-(2 Hydroxy-1-Naphthalidene) Antharanilic Acid with Some Lanthanides

The complexes of N-(2-hydroxy-1-naphthalidene)anthranilic acid abbreviated (H₂NA) with some trivalent rare earth elements (Pr, Nd, Sm, Gd, Dy, Er and Yb) were prepared. The complexes were characterized by chemical and thermal analysis, ir and conductimetric methods. Two types of ionic complexes; Ln(HNA)₂OH·2H₂O with Dy, Er and Yb, and Ln(HNA)₂OH with Pr, Nd, Sm and Gd were isolated. Coordination of the ligand with metal-ions occurs through the carboxy group and the nitrogen atom. The acid dissociation constants K₁ and K₂ of H₂NA and the overall stability constants β₁ and β₂ of some lanthanide complexes in 75% (v/v) dioxan-water solutions were determined by the potentiometric method.