Dispersed weathering products of carbonate rock: Features and formation conditions from the construction's point of view (by the example of Kazan, Russia)

Geological conditions of the Kazan city area are typical for East European Platform: alluvial sandy-clay sediments overlay the eroded surface of Permian, mainly carbonate section. Dispersed products of carbonate rock weathering appear at interfacial contact of these two associations. They can be attributed to a group of problem soils, because of their considerable inhomogeneity, irregular variability of physical-mechanical properties, internal instability, susceptibility to suffosion and solubility. All of these properties suggest the difficulties in implementation of field tests and in sampling, as well as in measurement of physical-mechanical properties in laboratory conditions. This paper presents laboratory test results on dispersed products of carbonate rock weathering sampled on the Kazan city area. A series of triaxial compression tests was conducted to understand the mechanical properties of these samples. The spatio-temporal model of carbonate weathering crust formation process is proposed. The recommendations are made for organization the engineering- geological research in the regions, where dispersed products of carbonate rock weathering. © 2013 Taylor & Francis Group, London

HIV Epidemics in the European Region: Vulnerability and Response

This report provides a systematic review of the evidence on HIV vulnerability and response in all 53 countries of the WHO European Region, stretching from Iceland to the borders of China. It focuses on key populations most at risk of HIV infection: people who inject drugs, sex workers and men who have sex with men. It confirms that these populations are disproportionately affected by the growing HIV epidemic in Europe. Twenty-five percent of HIV diagnoses in Europe are associated with injecting drug use, with much higher proportions in Eastern Europe (33%) than in Western Europe (5%) and Central Europe (7%). Sex between men accounted for 10% of all HIV diagnoses, with higher rates reported in Western Europe (36%), followed by Central Europe (22%) and Eastern Europe (0.5%). HIV remains relatively low among female sex workers who do not inject drugs, (less than 1%), but higher among those who inject drugs (over 10%) as well as among male and transgender sex workers. The analysis highlights the pivotal role of social and structural factors in shaping HIV epidemics and HIV prevention responses. Poverty, marginalization and stigma contribute to the HIV epidemic in Europe and Central Asia. Economic volatility and recession risks are increasing vulnerability to HIV and infections. Barriers to successful HIV responses include the criminalization of sex work, of sex between men, and of drug use combined with social stigmatization, violence and rights violations. HIV prevention requires social and environmental change. The report calls for policymakers and HIV program implementers to target the right policies and programs to maximize the health and social impacts of Europe’s HIV responses and get higher returns on HIV-related investments. The report is a product of a collaboration between the World Bank, the London School of Hygiene and Tropical Medicine, the WHO Regional Office for Europe and UNAIDS

Thiacalix[4] arenes with terminal thiol groups at the lower rim: Synthesis and structure

Methods were developed for the synthesis of ω-mercaptoalkoxy derivatives of thiacalix[4]-arenes in the 1,3-alternate conformation containing different numbers (2-5) of methylene spacers at the lower rim. The hydrazinolysis of the corresponding thioacetates is the most efficient method for the synthesis of these compounds. © 2009 Springer Science+Business Media, Inc

Transferred hyperfine interactions for Yb3+ ions in CsCa F 3 and Cs2 NaY F6 single crystals: Experimental and ab initio study

The results of an electron-nuclear double resonance study of the cubic paramagnetic Yb3+ center in Cs2 NaY F6 and CsCa F3 single crystals are presented. The values and signs of the transferred hyperfine interaction (THFI) parameters for several neighboring shells are determined. It is found that the relevant parameters for the two studied matrices differ, in spite of the fact that the nearest environment of the rare earth ion is nearly identical. A first-principles theoretical analysis is performed for the THFI parameters of the first coordination shell of F- ions. Several mechanisms of metal ion-ligand coupling are considered and it is found that one of them, ligand polarization, explains the difference observed for the THFI parameters in Cs2 NaY F6 and CsCa F3. © 2009 The American Physical Society

Synthesis and structure of lower rim-substituted alkynyl derivatives of thiacalix[4]arene

© 2015 Pleiades Publishing, Ltd. Lower-rim substituted bis- and tetrakis(alkynyloxy)thiacalix[4]arenes in cone and 1,3-alternate configurations were synthesized by the Mitsunobu reaction, and their structure was determined using homoand heteronuclear one- and two-dimensional NMR techniques. Bis(prop-2-yn-1-yloxy)thiacalix[4]arene was found to exist in conformational equilibrium whose position depends on the temperature and reaction conditions

Novel self-assembling systems based on amphiphilic phosphonium salt and polyethylene glycol. Kinetic arguments for synergetic aggregation behavior

Structural behavior and catalytic activity toward basic hydrolysis of O-alkyl-O-p-nitrophenyl chloromethyl phosphonates (alkyl=ethyl (S1) and hexyl (S2)) of mixed cetyl triphenyl phosphonium bromide (TPPB)-polyethylene glycol (PEG) systems are studied. The interdependence of aggregates and substrates is revealed from symbate changes in their self-diffusion coefficients determined by NMR FT-PGSE method. Much lower zeta-potentials of mixed systems as compared to single TPPB micelles are found, although the counterion binding of aggregates decreases with the addition of PEG. A 1.5-2-fold increase in the reactivity of phosphonates is shown to occur in mixed TPPB-PEG systems versus single surfactant micelles. In addition, a polymer induced shift of the onset of the rate acceleration toward the lower concentrations is observed. These findings provide strong evidences for synergetic solution behavior in the TPPB-PEG systems. The quantitative treatment of kinetic data in terms of pseudophase model sheds light on the factors of catalytic action. In the case of hydrolysis of S1, the more favorable microenvironment is responsible for the higher catalytic effect of mixed systems as compared to single TPPB micelles, while the factor of concentration decreases. The opposite trend is observed for hydrolysis of phosphonate S2, for which an increase in the micellar rate effect with the PEG addition is mainly contributed by the growth of the factor of concentration. © 2012 Elsevier B.V

Self-assembling systems based on amphiphilic alkyltriphenylphosphonium bromides: Elucidation of the role of head group

A systematic study of the aggregation behavior of alkyltriphenylphosphonium bromides (TPPB-n; n=8, 10, 12, 14, 16, 18; here n is the number of carbon atoms in alkyl groups) in aqueous solutions has been carried out and compared with trimethyl ammonium bromides (TMAB-n). Critical micelle concentrations (cmcs) of TPPB-n and TMAB-n decrease with the number of carbon atoms with the slope parameter of ca.0.3. The low cmcs and effective solubilization power toward Orange OT indicate high micellization capacity of phosphonium surfactants. The low counterion binding parameter β is revealed for TPPB-10 and TPPB-12, while high counterion binding of ≥80% is observed for high TPPB-n homologs. Values of the surface potential ψ calculated on the basis of pK a shifts of p-nitrophenols is similar for both series and monotonously increase with alkyl chain length. Several points indicate non-monotonic changes within TPPB-n series. There are peculiarities of the tensiometry and solubilization plots for high homologs and above mentioned increases in counterion binding on transiting from low to high molecular weight surfactants. Differences in aggregation behavior between TPPB and TMAB series and between low and high homologs can be due to the specific structural character of the TPP + cation, which is supported by X-ray data. © 2011 Elsevier Inc

Complex for Remote Execution of Laboratory Work on Radio Electronics

This paper presents the complex we have created for remote laboratory work on radio electronics, describes its principle of operation and features. The result of our work is a full-fledged complex with a set of laboratory works on the course of the basics of radio electronics