USING EIGENMODULI AND EIGENSTATES TO EVALUATE THE POSSIBILITY OF MARTENSITIC PHASE TRANSFORMATIONS

Journal of Applied Mechanics and Technical Physics - The possibility of phase transitions (martensitic transformations) in shape-memory alloys is evaluated using the concept of eigenmoduli...     

Chemical processes of structuring of furfural acetone monomer FA

The process of curing of furfural acetone monomer FA, which is used in production of wood—polymer composites, is considered. The paper suggests chemical reactions of autonomous structuring of two main components of the monomer FA—mono- and difurfurylidene acetone with formation of a spatial polymer, which leads to an increase in operational properties of wood-polymer materials.     

Novel Effectively Carbonaceous and Sulfurated Hydrogen Corrosion Inhibitors on the Basis of Organosulfurphosphorus Compounds

Abstract

Novel ammonium salts of O,O-dialkyl dithiophosphoric acids were obtained by one-pot synthesis from white phosphorus, elemental sulfur, industrial alcohols or phenols, and amines. Long-chain S-alkyl O,O-dialkyldithiophosphonates were prepared by the reaction of red phosphorus with elemental sulfur, alcohols, and the cheap industrial fractions of С₁₆–С₁₈ and С₂₀–С₂₆ of higher α-olefins in the presence of Lewis acid catalyst. The dithiophosphates obtained possess the high anticorrosion activities toward mild steel.     

Assessment of adhesion of adhesive compositions based on urea-formaldehyde oligomer modified with alcohols in relation to production of wood-based panels

This paper presents the results of calculation of adhesion for adhesive compounds based on a ureaformaldehyde oligomer KFN-66 modified with alcohols at a stage of mixing components with respect to production of wood-based panels for construction purposes. The optimum flow rate and type of the modifier for ensuring maximum work of adhesion are found.     

Investigation of rheological properties of modified carbamide-formaldehyde oligomers

Comparative results of determining the rheological properties of modified adhesive compositions based on carbamide-formaldehyde binders, main wood species, and flax shive are presented.     

The structure of mixed fluorides Ca1?xSrxF2 and Sr1?xBaxF2 and the luminescence of Eu2+ in these crystals

The structure of the mixed fluorites Ca_1−x Sr_xF₂ and Sr_1−x Ba_xF₂, as well as the structure of the Eu²⁺ impurity center in these crystals, is calculated within the framework of the virtual-crystal method realized in the shell model and pair-potential approximation. The phenomenological dependence of the position of the lower level of the 4f ⁶5d configuration of the Eu²⁺ ion on distance to the Eu²⁺-ligand is derived. The dependences of the Stokes shift and the Huang-Rhys factor on x are calculated for the yellow luminescence in Sr_1−x Ba_xF₂:Eu²⁺. The value of x at which the lower level of the 4f ⁶5d configuration of the Eu²⁺ ion in Sr_1−x Ba_xF₂:Eu²⁺ falls within the conduction band is found. __________ Translated from Fizika Tverdogo Tela, Vol. 45, No. 5, 2003, pp. 823–826. Original Russian Text Copyright ? 2003 by Nikiforov, Zakharov, Chernyshev, Ugryumov, Kotomanov.     

Local structure of Tm<Superscript>2+</Superscript> and Yb<Superscript>3+</Superscript> impurity centers in <Emphasis Type="Italic">Me</Emphasis>F<Subscript>2</Subscript> (<Emphasis Type="Italic">Me</Emphasis> = Ca,Sr, Ba) fluoride crystals

The local structure of Tm²⁺ and Yb³⁺ cubic impurity centers in MeF₂: Tm²⁺ and MeF₂: Yb³⁺ (Me = Ca, Sr, Ba) fluoride crystals, as well as Yb³⁺ trigonal and tetragonal impurity centers in MeF₂: Yb ³⁺ crystals, is calculated within the shell model in the pair potential approximation.     

The use of furan oligomers for modifying phenol-formaldehyde resin in plywood industry

The modification of phenol-formaldehyde resins by furan oligomers to increase the service characteristics of plywood and plywood products has been suggested. The strength properties, water resistance, fire resistance of plywood based on phenol resin SFZh-3013 modified by furfural-acetone FA monomer at the stage of the mixing of the adhesive composition components have been estimated.     

Adhesion of modified carbamide-formaldehyde oligomer

The calculation of the work of adhesion is presented for modified adhesive compositions based on Carbamide-formaldehyde resin used to develop plate materials. The modification of synthetic resins by alcohols is proven to reduce their surface tension to the level of the substrate, as well as to increase their ability to stick to a surface, the homogeneity of the distribution due to the particles of filling agents, and the work of adhesion.