Anomalies in the slow polarization kinetics of a ferroelectric relaxor in the temperature region of a diffuse phase transition

It is shown experimentally in the specific example of Cr-doped barium-strontium niobate that the anomalies in the infralow-frequency dielectric properties characteristic of a ferroelectric relaxor persist over the whole temperature region of the diffuse phase transition and decrease gradually with increasing temperature. Experimental data are presented on the anomalous quasi-static dielectric hysteresis loops, the slow polarization kinetics, and the anomalously broad energy-distribution spectra of potential barriers. The anomalies are a signature and a quantitative measure of the structural disorder typical of a relaxor.     

Synthesis of Deuterium- or Tritium-Labeled Norepinephrine and Evaluation of Its Biological Activity

A labeled norepinephrine analogue was prepared by bromination of norepinephrine with subsequent debromination with tritium or deuterium gas. The yield of tritiated norepinephrine was 10–20% with a molar radioactivity of 27 Ci/mmol. The biological activity of tritiated norepinephrine was evaluated by analyzing its specific capture by noradrenergic neutrons in thick sections of the brainstem and midbrain of Wistar rats, and in a suspension of cells of pheochromocytoma PC12 expressing the membrane transporter of norepinephrine. It is shown that tritium-labeled norepinephrine synthesized by the proposed method does not differ in biological activity from the natural norepinephrine.     

Fischer cyclization of 6-substituted pyrid-2-ylhydrazones of cyclohexanone

The influence of substituents in position 6 of the pyridine nucleus on the Fischer cyclization of cyclohexanone pyrid-2-ylhydrazones under the action of various catalysts has been studied. It has been established that the yields of the normal indolization products, derivatives of 5,6,7,8-tetrahydro--carboline, increase regularly on passing from the unsaturated compound to the 6-methyl- and further to the 6-bromopyrid-2-ylhydrazones. The results obtained have been compared with the capacity of the pyridine nitrogen in the hydrazones mentioned for undergoing nucleophilic addition and substitution reactions.     

Synthesis of nanoparticles of iron triade metals in water solutions

Nanodispersed metals of iron triade prepared by reduction of their complexes in water solutions were studied by the transmitting electronic spectroscopy and the X-ray diffractometry. It is shown that the particles have dimensions about 50–100 nm, but are inclined to the formation of the needle-like aggregates due to their magnetization. It is established that the main phase in the samples under study is the metal of iron triade.     

Incorporation of sodium into silicon dioxide film fabricated in glow discharge plasma

Results of experiments on the plasma-assisted fabrication of a silicon dioxide film with incorporated sodium are reported. The film was obtained via the decomposition of vaporized tetraethoxysilane and sodium compounds in a glow-discharge plasma and the deposition of the degradation products on a substrate. It is shown that this procedure makes it possible to incorporate up to 7 wt % sodium in the film composition.     

Quantitave determination of losartan and its metabolite E-3174 in rat urine

A technique for the quantitative determination of losartan and its metabolite E-3174 in biological liquids (rat urine) has been developed. The analysis was carried out using high-performance liquid chromatography coupled with fluorescence detection. The technique??s detection limit for losartan and E-3174 was equal to 2.5 ng/mL and 5 ng/mL, respectively.     

Study of possible void nucleation and growth in solids in the framework of the Davis-Nadai deformation theory

In the framework of the Davis-Nadai deformation theory, we study the problem of a ball with a central cavity subjected to internal and external pressure. The solution is constructed in the reference configuration for the polynomial material deformation law with possible regard to matter conservation inside the cavity. The obtained solution is analyzed; it is mathematically proved that the limit load exists in the case of uniform compression, and a method for determining this load is given. It is also proved that a new void can be formed in a solid ball in the case of its extension, and the critical load of void formation is estimated. It is shown that the already existing spherical void cannot completely disappear under the action of external pressure (assuming that its shape is preserved and remaining in the framework of the continuity hypothesis).     

Aqueous photocatalytic oxidation of prednisolone

The research into the aqueous photocatalytic oxidation of the anti-inflammatory drug prednisolone was undertaken with P25 titanium dioxide (Evonik) and visible light-sensitive sol-gel synthesized titania-based photocatalysts containing carbon, sulphur, and iron. Possible prednisolone photocatalytic oxidation reaction pathways were proposed based on a number of oxidation by-products determined in the present study. The prednisolone adsorption properties, effects of initial prednisolone concentration, pH, usual wastewater matrix admixtures, like carbamide and sucrose, were studied. The nontoxicity of doped catalysts towards Tetrahymena thermophila, a ciliate protozoa present in the activated sludge, indicated their lower oxidative ability compared to P25, but also implied their potential application in pre-treatment of toxic hazardous materials under VIS or solar radiation before the biological degradation stage.