Diagnostics of Density Fields in Hypersonic Flows around a Cone in a Light-Gas Gun by the Shadow Photometric Method

Technical Physics - A novel approach to obtaining hypersonic flows is proposed and the results of experimental study of hypersonic flows around cones with semivertex angles τ1 = 3° and...     

Reactivity of oximes of 1-aryl(hetaryl)-2-(hydroxyamino)propan-1-ones with ethyl glyoxylate

Chemistry of Heterocyclic Compounds - Alkyl(hetero)aromatic α-hydroxyamino oximes with the anti configuration of the oxime group reacted with ethyl glyoxylate to form...     

Influence of the surface functionalization conditions on the properties of carbon fibers and supported palladium

The influence exerted by the conditions of oxidation and calcination in an inert medium on the properties of Karbopon and Busofit activated carbon fibers were studied using a set of physicochemical methods. The maximal concentration of thermally stable phenol groups in Busofit is reached by its oxidation with a 20% aqueous HNO₃ solution, followed by calcination in an inert medium at 500°С for 1.5 h. Experiments with catalysts supported on Busofit samples functionalized with 20% HNO₃ have shown that palladium supported on Busofit that was calcined at 500°C after oxidative treatment is characterized by monodisperse nanocluster distribution. The prepared catalysts containing 1 wt % Pd exhibit higher activity in oxidation of carbon monoxide than their presently known analogs do.     

Complexation of Arabinogalactan with Copper(II) Ions in Aqueous Solutions

Complexation of Cu(II) with arabinogalactan as influenced by solution pH was studied by spectrophotometry and the method of dialysis equilibrium. Copper ions form complexes with arabinogalactan in a wide pH range, pH 5.0-12.5. Arabinogalactan forms two complex species with the metal. The composition and formation constant of the complex formed at pH <10.8 were determined.     

The asymptotic behavior of the Green function of the boundary-value problem for a second-order equation on a geometric graph

The boundary-value problem (where s is a complex parameter with Re s > 0) on an open connected geometric graph is considered. The asymptotic behavior as Im s → ∞ of the Green function is determined; it implies that the Green function has a preimage under the one-sided Laplace transform. __________ Translated from Sovremennaya Matematika i Ee Prilozheniya (Contemporary Mathematics and Its Applications), Vol. 38, Suzdal Conference-2004, Part 3, 2006.     

Features of the in situ formation of a linear poly(methyl methacrylate)-crosslinked polyurethane blend in the presence of an oligomeric initiator

The process of the in situ formation of a linear poly(methyl methacrylate)-crosslinked polyurethane blend in the presence of different amounts of an oligomeric azo initiator containing fragments of a polyurethane chain and groups capable of initiating the radical polymerization of methyl methacrylate has been studied. It has been shown that the use of an azo initiator providing for the formation of block copolymers retards the phase separation in the system and favors the formation of a finer blend structure that is characteristic by a domain size several times smaller than that of the pristine blend, without the azo initiator. The optimum azo initiator concentration that results in a better dispersion of polyurethane in poly(methyl methacrylate) has been determined.     

Short-range orientational order in polymer-solvent systems

This review presents the results on studying short-range order in polymer solutions by polarization optical, electrooptical, and spectroscopic methods. The effect of short-range orientational order on dynamic birefringence, photoelasticity, electric-field-induced birefringence, IR absorption spectra, and fluorescence polarization in polymer-solvent systems has been studied. The problem concerning the account for internal field in optical and electrooptical experiments is considered. We present the results on studying the effect of characteristics of both a polymer and a solvent on the parameters characterizing short-range orientational order in polymer solutions.     

Numerical calculation of directional diagrams and profiles of evaporators with an accelerating nozzle

We investigate the possibility of achieving optimal directional diagrams of molecular flow and optimal profiles in evaporators with an accelerating nozzle. The numerical calculations elucidate the factors that have an essential effect on the thickness and uniformity of the coating formed by metal vapors on the substrate.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 59, pp. 70–76, 1986.