Magma degassing during eruption through water-saturated porous rocks

In the case of extrusive eruption, we consider the problem on magma degassing which rises in a volcano conduit crossing porous water-saturated rocks. We show that the intensity of outflow of volcanic gases into the rocks is comparable to the intensity of their transport with the rising magma. The magma degassing in the rocks substantially affects the eruption dynamics, in particular, the duration of the periods of eruptive activity.     

Growth Morphology and Structure Peculiarities of Superthin Titanium Films

Superthin titanium films of 0.3 to 2 nm thickness, prepared by radio-frequency sputtering, have been studied by modern X-ray methods, such as reflectometry, fluorescent analysis and grasing-beam structural analysis. Two simple models were used to describe early stages of film growth. It has been shown that the thinnest titanium films were the TiO₂ islands with an equal height. Thicker films could be described as bilayers Ti/TiO₂. The films became continuous already near 1.5 nm effective thickness.     

Conformational changes in poly(vinyl alcohol)-graft-polyacrylamide in aqueous solutions vs graft content

Conformational changes have been studied in intramolecular polymer-polymer complexes (intraPC) of graft copolymers of poly(acrylamide) and poly(vinyl alcohol) (PVA-g-PAA) with various numbers of grafts (4-42) per molecule as a function of temperature and copolymer concentration. It is shown that the magnitude of conformational change depends on the grafts content while the temperature range over which the conformation changes occur is essentially determined by copolymer concentration. The conformational changes are reversible on heating and cooling.     

Crystal Structure and Growth Morphology of Nickel Superthin Films

Ni superthin films of t = 0.3–3.5 nm thickness prepared by radio-frequency sputtering have been studied by mordern X-ray methods, such as reflectometry, fluorescence analysis and grazing-beam structure analysis. The results have shown that the films were polycrystalline and their densities correspond to bulk values for nickel already at the early stage of growth. None oxides were found in Ni films. The model of earliest stage film growing have been suggested: film begins to grow by the island mechanism, but the crystallization front remains perfectly plane during the growth.