Study of regularities of the cure of adhesion-active compound

The effect of components of ETAL-148TG-2 compound containing epoxyurethane oligomer, liquid aromatic curing agent, and mineral filler with ammonium polyphosphate on its rheological properties is studied. Constants of the processes of viscous flow, cure, and gelation of the compound are determined. Revealed rheokinetic regularities of the cure of compound make it possible to choose optimal conditions for its processing and cure.     

Estimation of the properties of an energy-dispersive X-ray fluorescence spectrometer based on a composite double-layer detector

A mathematical model of double-layer Si-Ge and Si-AsGa energy-dispersive detectors of X-rays based on the analysis of processes of radiation and electron transfer in the detector is proposed along with a model of an energy-dispersive X-ray fluorescence spectrometer on the basis of this detector. The probabilities of recording of photons in different sections of the detector response function are calculated using the Monte-Carlo technique. It is shown that, in using an anticoincidence circuit and a Si detector as the first layer and Ge or AsGa detectors as the second layer, a detector with improved characteristics can be obtained, namely, the suppressed loss peaks of Ge or As and Ga and the efficiency of detection at the high radiation energy close to that of the Ge or AsGa detector. This detector in the energy-dispersive X-ray fluorescence spectrometer in some cases allows the reduction of the background level.     

Mechanisms of B Meson Suppression in Ultrarelativistic Heavy Ion Collisions

Journal of Experimental and Theoretical Physics - Different mechanisms of B meson suppression in lead ion collisions at an energy of the Large Hadron Collider $$\sqrt {{{s}_{{NN}}}} $$ = 5.02 TeV...     

Adsorption of Cationic Surfactants on Silica Surface: 1. Adsorption Isotherms and Surface Charge

Adsorption isotherms of cationic surfactant, dodecylpyridinium chloride, on an Aerosil OX50 and isotherms of surface charge against the background of 0.001- and 0.1-M KCl solutions at pH 7 and 9 were measured and analyzed. Different forms of adsorption isotherms of surfactants at low and high electrolyte concentrations are explained from differences in the formation of the surface charge of Aerosil. Comparison of the isotherms of surfactant adsorption and surface charge allowed us to make conclusions about the surfactant orientation and structure of an adsorption layer, as well as to determine the fraction of surfactant molecules in the first and second adsorption layers.     

Structure and Electrosurface Properties of Porous Glasses with Different Compositions in KCl and NaCl Solutions

For porous glasses with and without small amounts of fluorine and phosphorus, structural (specific surface area, structure resistance coefficient, and mean pore radius) and electrosurface characteristics (adsorption of potential-determining ions, conductivity, counterion transport numbers, and electrokinetic potential) in sodium and potassium chloride solutions are compared. Results of measuring the equilibrium and transport characteristics of membranes are used to calculate the constants of surface reactions and adsorption potentials of ions within the framework of the 2-pK model of oxide surface charging. Within the framework of the homogeneous model, electrochemical characteristics of porous glasses, namely, concentrations of co- and counterions in a pore-confined liquid, Donnan potentials, convective component of the conductivity of a pore-confined solution, and mobility of counterions in the membranes, are calculated.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 3, 2005, pp. 342–351.Original Russian Text Copyright © 2005 by Ermakova, Medvedeva, Volkova, Sidorova, Antropova.     

Reaction of fullerene C60 with 2-azido-4,6-diphenylpyrimidine

The first representative of the pyrimidine-substituted [60]fullereno[1,2-b]aziridines was synthesized by the reaction of fullerene C₆₀ with 2-azido-4,6-diphenylpyrimidine. 2-(Azahomo[60]fullereno)-4,6-diphenylpyrimidine was found to be formed as a by-product. The electrochemical properties of the adducts were studied.     

Fluorine-Containing Heterocycles: VIII. Transformations of 2-Polyfluorobenzoylacrylates Having a Thiosemicarbazide Fragment

Depending on the conditions, 3-(4-R-thiosemicarbazido)-2-polyfluorobenzoylacrylates can be converted into the corresponding potassium salts, [1,3,4]thiadiazino[6,5,4-ij]quinolines, and pyrazole or 1,3,4-thiadiazole derivatives.     

High concentrated solutions of surfactants and nature of the black foam films. A study of electroconductivity

Summary The analogy between the properties of the high concentrated surfactant solutions and the black foam films is discussed. Measurements of the specific electric conductance of high concentrated (40–60 %) sodium lauryl sulphate solutions are carried out with the aid of a special conductance cell (fig. 1). The temperature dependence of for several surfactant concentrations is compared on fig. 3 with the temperature dependence of the specific electric conductance f of the black foam films. The results show that at low temperatures a complete analogy between the electroconductivity properties of the second black film on one hand and the surfactant-water gel on the other is evident, which indicates an analogy between the structures of these two systems. A further analogy is available between the electroconductivities and respectively the structures of the first black film and the liquid crystal phase surfactant-water, both being stable at higher temperatures.

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Zusammenfassung Die Analogie zwischen den Eigenschaften der hochkonzentrierten Tensidlbsungen und der schwarzen Schaumlamellen wird diskutiert. Es wurden Messungen der elektrischen Leitfähigkeit von hochkonzentrierten (40–60%) Natriumdodecylsulphatlösungen mit der Hilfe einer speziellen Zelle (Fig. 1) durchgeführt. Die Temperaturabhängigkeit von für einige Tensidkonzentrationen wurde mit der Temperaturabhängigkeit der spezifischen elektrischen Leitfähigkeit f von den schwarzen Schaumlamellen verglichen. Die Ergebnisse zeigen eine Analogie zwischen den elektroleitenden Eigenschaften des zweiten schwarzen Films und des Tensid-Wassergels bei niedrigen Temperaturen, was für eine Analogie zwischen den Strukturen dieser beiden Systeme spricht. Eine weitere Analogie wird bei höheren Temperaturen beobachtet, zwischen den elektrischen Leitfähigkeiten und beziehungsweise den Strukturen des ersten schwarzen Films und der lyotropen flüssigkristallinen Tensid-Wasserphase.

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With 3 figures and 1 table     

A mathematical algorithm of distributing the greenhouse gas emissions

In connection with the urgent problem of climate change and with the purpose of reaching an agreement between greenhouse gas emitters (on the scales of the entire world, an individual country, one of its regions, or a big city), a mathematical algorithm is proposed for distributing the emission of these gases.