Some features of formation and dissolution of a series of Pu(IV) and Zr alkyl and butyl alkyl phosphates in the system tBP — N-dodecane — Nitric acid — Water

The formation and composition of salts produced on interaction of a series of alkyl- and butylalkylphosphoric acids having alkyl radical chain lengths from C₄ to C₁₀ with Pu(IV) and Zr in organic and aqueous phases of the system TBP — n-dodecane — nitric acid — water have been studied. The composition of compounds was found to depend on the conditions of their formation, being defined first of all by the HNO₃ concentration in aqueous and organic phases.     

Change in structure and properties of carbon steels bombarded by a 10−5 to 10−4 second high-energy electron beam

We consider the hardening characteristics and features of the structural and phase transformations in carbon steel (0.7% C) quenched from the melt using an electron beam with electron energy 130–180 keV, pulse duration 10–200 msec and power density 10⁶ to 10⁷ W/cm². We have observed that maximum hardening is achieved for pulse duration 40 msec. The nonmonotonic character of the dependence of the degree of hardening on the pulse duration is connected with the substantial effect of the beam parameters on the phase composition and morphology of the rapidly quenched structures.Institute of Power Electronics, Siberian Branch, Russian Academy of Sciences; Tomsk State Architectural Design Academy. Institute of the Physics of Strength and Materials Science, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, p. 42–50, October, 1995.     

Interaction between indigo and adsorbed protein as a major factor causing backstaining during cellulase treatment of cotton fabrics

A model microassay system was developed to measure indigo backstaining on cotton fabrics in the presence of enzymes on a small laboratory scale. Backstaining indexes for 11 cellulase samples were measured, and the enzymes were ranked from lower to higher backstaining. Two multienzyme cellulase preparations were separated into fractions using chromatofocusing on a Mono P column. Adsorption ability and backstaining properties of purified enzyme fractions were studied. Evidence was obtained that protein adsorption on cotton fabrics is a crucial parameter causing backstaining (both for crude cellulase samples and purified enzyme components).     

Evaluation of cellulase preparations for hydrolysis of hardwood substrates

Seven cellulase preparations from Penicillium and Trichoderma spp. were evaluated for their ability to hydrolyze the cellulose fraction of hardwoods (yellow poplar and red maple) pretreated by organosolv extraction, as well as model cellulosic substrates such as filter paper. There was no significant correlation among hydrolytic performance on pretreated hardwood, based on glucose release, and filter paper activity. However, performance on pretreated hardwood showed significant correlations to the levels of endogenous β-glucosidase and xylanase activities in the cellulase preparation. Accordingly, differences in performance were reduced or eliminated following supplementation with a crude β-glucosidase preparation containing both activities. These results complement a previous investigation using softwoods pretreated by either organosolv extraction or steam explosion. Cellulase preparations that performed best on hardwood also showed superior performance on the softwood substrates.     

The effect of the manufacturing procedure on the electric properties of carbon-black-filled,fiberglass-reinforced thermoplastic composites

The electric properties of carbon-black-filled, fiberglass reinforced thermoplastic composites with unidirectional and random structure were studied. Their samples were prepared according to various manufacturing processes: injection molding, molding, press molding, winding, and pultrusion. It was shown that the electric properties of the composites are determined by the character of distribution of filler particles in the polymer matrix, which is closely related to the blending parameters and the engineering properties of the material.     

Accurate measurement of the exciton diffusion length in a conjugated polymer using a heterostructure with a side-chain cross-linked fullerene layer

Exciton diffusion and photoluminescence quenching in conjugated polymer/fullerene heterostructures are studied by time-resolved photoluminescence. It is observed that heterostructures consisting of a spin-coated poly(p-phenylene vinylene) (PPV)-based derivative and evaporated C60 are ill-defined because of diffusion of C60 into the polymer, leading to an overestimation of the exciton diffusion length. This artifact is resolved by the use of a novel, thermally side-chain polymerizing and cross-linking fullerene derivative (F2D) containing two diacetylene moieties, forming a completely immobilized electron acceptor layer. With this heterostructure test system, an exciton diffusion length of 5 +/- 1 nm is derived for this PPV derivative from time-integrated luminescence quenching data.     

Stability of zirconium oxides in Nb-Mo-ZrO2 alloy

The paper gives the results of investigations on the rate of coalescence of zirconium oxides in Nb-Mo-ZrO₂ alloy. On the basis of experimental results and theoretical estimates, it is shown that the stability of zirconium oxides in a niobium matrix increases substantially when the oxygen content in the solid solution rises. A high stability of zirconium oxides in niobium, which ensures a considerable (up to T 1800°C) increase in the recrystallization temperature and enhancement of the mechanical properties of the alloys at T 1100°C can be attained at an oxygen content C₀ 0.2–0.5 at.% in the solid solution.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 76–79, May, 1982.     

Kinetic aspects of hydrochemical deposition of cadmium sulfide from solutions with diverse ligand backgrounds

A comparative kinetic study was carried out and formal kinetic equations were derived for the chemical deposition of cadmium sulfide from aqueous solutions containing various cadmium complexes onto a glass-ceramic substrate by thiourea under conditions of spontaneous nucleation and interfacial area control. The elemental composition and morphology of the resultant films were examined, on this basis their nanostructure nature was confirmed, taking into account the data on crystallite size analysis.