Открытый доступ
Доступ предоставлен
Только для подписчиков
Том 72, № 2 (2017)
- Год: 2017
- Статей: 4
- URL: https://bakhtiniada.ru/0027-1314/issue/view/9932
Article
Structural rationale of a non-Newtonian flow
Аннотация
The complex rheological behavior of structured systems, namely, suspensions, emulsions, polymer melts and solutions, micellar fluids, and liquid crystalline systems is analyzed. The behavior of such systems is characterized by the coexistence of different flow regimes in a wide range of shear rates. It is shown that the generalized flow equation (GFE) effectively describes plastic and pseudoplastic flow systems. The Newtonian and non-Newtonian behavior of structured flowable systems is explained within the structural microrheological model.
69-91
Application of microemulsions for the extraction of o-phthalate esters from soil with subsequent separation of microemulsions, simultaneous preconcentration, and gas chromatographic analysis of target components
Аннотация
The possible application of microemulsions as extractants for the extraction of o-phthalate esters from soils with the subsequent breakdown of microemulsions, simultaneous preconcentration of dialkhylphthalates in the organic phase, and their following gas chromatographic analysis with mass-spectrometric detection is demonstrated. The preconcentration factor was 18. The method is characterized by low detection limits, good selectivity, and reproducibility.
92-96
Synthesis and structural study of 3-phenyl-6,7,8,9-tetrahydrocyclopenta[a]naphthalene-containing ansa-complexes of zirconium
Аннотация
The zirconium rac- and meso-complexes of the ansa-type that contain a 3-phenyl-6,7,8,9-tetrahydrocyclopenta[a]naphthalene fragment and a dimethylsilylene bridge are synthesized. The compounds obtained are characterized by NMR spectroscopy; the structure of rac-complex is studied by X-ray diffraction, which maked it possible to evaluate the steric availability of the zirconium center in the corresponding catalysts for the olefin polymerization.
97-103
Dynamic surface tension parameters of protein–lipid–salt solutions as a system simulating blood plasma
Аннотация
Measurements of the dynamic surface tension (DST) of liquids is one of the simplest and fastest methods for the analysis of various chemical solutions and biological liquids. Solutions of the three-component systems on the basis of bovine serum albumin (BSA), natural phosphatidylcholine (PC), and sodium chloride are investigated. It is found that the salt content (especially at high concentrations) exerts a major impact during short time periods (0.1–1.0 s); and the BSA concentration, in intermediate and long time periods (over 1.0 s); however, changes in the PC concentration (in the range of concentrations typical for blood) insignificantly affect most of the DST parameters. The changes (by 22–68%) of the tensiogram slope values, λ0, λ1, and λ2, are most informative among the seven studied DST parameters. This has allowed us to determine the optimal concentrations ranges for BSA (60–80 g/L), PC (1–4 mM), and NaCl (130–150 mM) in the mixture, which correspond to their content in the blood plasma of humans and animals. For four parameters, σ1…σ4, only small correlations with changes in the proportion of the three components in the mixture are found. The obtained relationships are important for both supplementing fundamental databases and prognostic modeling in biology and medicine.
104-109