Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


The Experimental Study of Solubility of Helium in Propan-2-ol at Temperatures 360, 420 and 480 К

The experimental study of solubility of helium in propan-2-ol at high pressures and temperatures was performed. The following values of Henry’s law constants for the solution of helium in propan-2-ol were obtained: 168,7 ± 6,3 MPa at 480 К, 341,2 ± 13,6 MPa at 420 К and 602,0 ± 43,5 MPa at 360 К.

Phase Diagrams of the Ternary Systems Potassium Carbonate + Water + Hydrocarbon at 25°С

The phase diagrams of the ternary systems potassium carbo- nate+water+hydrocarbon (toluene, n.dodecane) at 25°С were first studied by means of the methods of sections and isothermal titration. The phase diagrams of both systems belong to those of ternary systems with salting-out of the binary heterogeneous system. Potassium carbon- ate sesquihydrate is the solid phase of monotectic equilibrium. Nine tie lines were drawn on the delamination field of the phase diagram of each ternary system.

Modelling of Drying Process of Natural Gas at a Pressure of 20–25 MPa through Aluminogel and NaA 4A Zeolite

Containment of water vapor in natural gas prevents its transportation and applying as an internal combustion fuel. The most demanded drying technology is adsorption at high pressure. The construction of a mathematical model for predicting the process is a significant task. Through a mathematical model of the process of water adsorption from natural gas at pressures of 20–25 MPa and temperatures of 5–40°C in the presence of NaA 4A zeolite and aluminogel, commonly used dehumidifier, optimal drying conditions were selected.

Synthesis and Structure Mixedligand Complexes of Fe, Co and Ni with Dimerkaptophenols and Heterocyclic Diamines

Physico-chemical methods investigated complexing Fe (II, III), Co (II) and Ni (II) with di mer kap tophenols (2,6-dimerkaptophenol, 2,6-dimercapto- 4-methylphenol, 2,6-dimercapto-4-ethy l phenol, 2,6-dimercapto-4-propylphenol and 2,6-dimercapto-4-tert-butylphenol), and hyd rophobic amines. The hydrophobic amine were used as heterocyclic diamine- 1,10-phenan thro line, 2,2’-bipyridyl and 4,7-diphenyl-1,10-phenanthroline (batofenantrolin). The optimal conditions for the formation and extraction mixedligand complexes and set the ratio of the components in the complexes.

Investigation of the Structure and Ways of Formation of Isomeric Tyenylsubstituted Triazolohexohydroquinazolines by Methods of NMR Spectroscopy and Chromato-mass-spectromectry

In the three-component condensation of thiophenecarbaldehyde, cyclohexanone and 3-amino-1,2,4-triazole triazolohexahydroquinazolines are formed, which are isomeric in the type of the ring junction and the double bond position in them, the structure of which is established by 1H NMR spectra. With the GC-EIMS-analysis of the composition of the reaction mass at various temperatures, it has been established that an intermediate in the formation of final products is azomethine (instead of a possible ?,?-unsaturated ketone).

The Determination of Biological Effects of New Heterocyclic Compounds on Plants and the Evaluation of Environmental Safety of Their Application

Еcotoxicological evaluation of two new polyheterocyclic compounds was spending. Acute toxicity of test substances, their lethal and safe concentration (LC and BC) were determined. The nature of the biological effect of these compounds on the plants was investigated. The substances were stimulants during the germination of seeds of wheat and peas and inhibitors of the growth of the roots and stems of seedlings. It was determined the effect of various concentrations of tested compounds on the growth characteristics of plants.

Screen-printed Potentiometric Sensors for Cefuroxime Axetil Determination in Small Sample Volumes

Potentiometric screen-printed cefuroxime axetil sensors were developed. The optimum membraneand carbon ink compositions were determined. The main sensor electroanalytical and operational characteristics were evaluated. The sensors were used to determination of cefuroxime axetil in small sample volumes of model water solutions and mixed saliva (oral fluid). Upgrading sensor designs opens up new sensor application for pharmaceutical kinetic antibiotic studies on the mixed saliva analysis and correction treatment of various pathological processes.

Chemometric Method of PLS in the Treatment of Titrimetric Data when Opredeleniye of Arginine and Lysine in Mixed Solutions

Arginine and lysine are the most important ?-amino acids that are part of many proteins, which play an important role in the processes of nitrogen metabolism, growth and restoration of body tissues. It is used in medical nutrition in the postoperative recovery period, as well as as diagnostic factors. The simple express methods of separately determining the main ?-amino acids of arginine and lysine in their mixed solutions are in demand.

Antioxidant Status of Macrobasidiomycetes Mycelium Grown in the Presence of Organoselenium Compounds

Antioxidant status maintenance plays a significant role for mushroom cultures in respect to oxidative stress resistance, cytodifferentiation and transition to the generative stage. Strong antioxidants are the selenium compounds. One of the antioxidant action indices is the antiradical activity determined by means of the spectrophotometric method using the reactions with the free radical 1,1-diphenyl-2-picrylhydrazyl (2,2-diphenyl-1-picrylhydrazyl, N,N-diphenyl-N’-picrylhydrazyl, DPPH) (C6H5) 2N– N•–C6H2(NO2) 3-2,4,6.

Equilibrium Liquid–Liquid–Solid and Critical Phenomena in the Quaternary System Cesium Nitrate+Water+Pyridine+Butyric Acid with in the Range of 5 to 60°C

Phase equilibria and critical phenomena in the component mixtures of a cut of the composition tetrahedron of the quaternary system cesium nitrate + water + pyridine + butyric acid were studied in the range of 5–60°C by the visual-polythermic method. The phase equilibria in the component mixtures were studied using sections of one cut of the composition tetrahedron.