A technique for measuring charges of relativistic nuclei in a nuclear emulsion on the PAVICOM automated facility

A technique for measuring the charges of relativistic nuclei in thick emulsion layers irradiated in a longitudinal direction is described. This technique has been implemented on the PAVICOM completely automated facility at the Lebedev Physical Institute. The calibration curves for relativistic nuclei with Z > 3 are presented. The advantages of this technique are demonstrated using charge measurements of ²⁸Si nuclear fragments as an example.     

Application of mass spectrometry with laser desorption/ionization for studies of lead clusters on surfaces of different types

Ionization of model compounds is studied using the example of lead halides with the method of mass spectrometry with surface-activated laser desorption/ionization (SALDI) on surfaces of different types. Clusters of lead halides are determined in a wide range of masses, up to 2 kDa. The dependence of ionization on the concentration, support type, and method of application of model samples is shown. The surface of a fragment of the combustion chamber of a liquid rocket engine is studied using the method of SALDI mass spectrometry. Lead and oxides and chlorides thereof are detected on the surface of a combustion-chamber fragment. It is suggested that peeling of a nickel coating may be caused by the presence of lead clusters at the nickel-bronze interface.     

Vapor-Phase Protection of Zinc from Atmospheric Corrosion by Low-Volatile Corrosion Inhibitors

Protection of Metals and Physical Chemistry of Surfaces - The atmospheric corrosion resistance of metals can be reached by the formation of ultrathin protective films on their surface. Over recent...     

Study of Evaporative Convection in an Open Cavity under Shear Stress Flow

When a layer of volatile liquid is exposed to a shear flow of inert gas, thermal patterns, in the form of interfacial ripples and bulk plumes, are created by the combined action of evaporative, shear-driven and surface-tension-driven instabilities. The topology of the interfacial thermal patterns is mainly influenced by the geometry of the evaporating surface, the thickness of the evaporating layer, the intensity of the shear flow and by the physic-chemical properties of the working fluid. In this paper, by means of numerical simulations, we focused our attention on the dynamics of the interfacial thermal patterns for different working fluids and thicknesses of the volatile liquid layer. This study has been performed in the frame of the ESA sponsored Space Program on heat and mass transfer CIMEX-1. The choice of the fluids—ethyl alcohol and FC72 (n-perfluorohexane)—the reference values for the inert gas flow rate, the thickness of the liquid layer as well as the geometrical features of the computational domain correspond exactly to the ones foreseen for the CIMEX-1 experiment. However, the main conclusions can be considered of more general validity.     

Protective properties of oil-soluble corrosion inhibitors based on alkenylsuccinic anhydride

Conclusions Additives and corrosion inhibitors based on alkenylsuccinic anhydride have been studied in relation to their effects on the corrosion of ferrous and nonferrous metals under conditions of chemical, electrochemical, and mixed chemical/electrochemical corrosion.A series of salts of alkenylsuccinic acid has been synthesized, also succinimides based on urea, and a complex corrosion-inhibiting additive.It has been shown that, for the protection of engines and mechanisms against corrosive wear, use should be made of oil-soluble, multifunctional, complex additives that will provide simultaneous protection of metals against chemical and electrochemical corrosion.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 10, pp. 38–41, October, 1970.     

Towards development of colorimetric test-systems for phenols detection based on computationally-designed molecularly imprinted polymer membranes

Colorimetric test-system for the express-control of phenols content in water was developed. The system consisted of free-standing molecularly imprinted polymer (MIP) membranes which contained synthetic binding sites capable of phenol binding. The MIP membranes were obtained by co-polymerisation of a functional monomer (e.g. itaconic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, acrylamide or methacrylic acid) with triethyleneglycoldimethacrylate and oligourethaneacrylate. Rational choice of the functional monomers was based on the results of computational modelling. The phenol-selective MIP membranes were used as a basis for the colorimetric test-system for measuring phenol in aqueous samples. Phenol molecules were selectively adsorbed by the MIP membranes and quantified using color reaction with 4-aminoantipyrine. The intensity of the membranes' staining was proportional to the phenol concentration in the analysed sample. The optimised colorimetric test-system based on MIP membranes demonstrated a low detection limit (50 nM), a wide working range — 50 nM–0.5 mM and an excellent storage stability at room temperature (12 months). As compared to the traditional methods of phenols detection the developed test-system is superior because of simplicity of operation, small size and low cost.     

Digestive function of the small intestine and pancreas in rats on artificial feeding

Full-value diets of similar composition were given to male rats weighing 207-230 g, by intravenous (group 1) or intragastric (group 2) routes. The proportion of amino acids, fats and carbohydrates was 9.9:15.7:74.4 (with regard to their calorific value). The diet calorific value comprised 60.6 kcal/rat/day. An average mass increase in group 1 was 2.44 +/- 0.14 g/day, in group 2 - 1.75 +/- 0.11 g/day. The protein content and activities of alpha- and gamma-amylase, invertase, maltase, and glycil-L-leucine dipeptidase were assayed in the intestinal mucosa of the proximal portion of the small intestine in group 1 rats, while a decreased alpha-amylase activity in the distal portion of the small intestine was recorded in the animals of group 2. The mass of the pancreas in the rats of group 1 and 2 was authentically lower than in the control rats which received oral feeding with natural foods. The lowest mass of the pancreas was observed in the rats of group 1. Specific activity of trypsin, lipase and RNase in the pancreatic tissues of rats in groups 1 and 2 was similar. The results of the study have evidenced a lowered function of the digestive system under conditions of artificial feeding, especially in case of intravenous nutrition.