Physicochemical investigation of anodic processes involved in silver electrowinning in refining technology

During silver electrowinning in refining technology, irrespectively of the nature of electrolyte and anode material, an anode deposit is formed due to oxidation of singly charged silver ions to higher degrees of oxidation (+2 and +3) under polarization. Absorption spectra of Ag(II) have been obtained in solutions with various concentrations of silver ions and nitric acid using anodic polarization in combination with electronic absorption spectroscopy; silver ions of high oxidation degrees were found to be unstable in solutions. At anode potentials φa ≥ 1.15-1.22 V, Ag(I) ions in liquid phase are oxidized to Ag(II), which paint the anolyte; their content depends on silver and nitric acid concentrations in the electrolyte. The deposit crystallizes on anode at potential φa ≈ 1.5 V. Chemical analysis, X-ray powder diffraction, and a thermogravimetric study of the anode deposit have made it possible to identify its initial composition as Ag 7O8NO3. The deposit composition varies in time as a result of reduction of highly oxidized silver. © 2013 Pleiades Publishing, Ltd

Peculiarities of angiogenesis in testicular embryonal carcinoma

Despite the relatively low incidence of testicular germ cell tumors (TGCT), which amount only 1% of all cancers in men worldwide in the epidemiological aspect, unlike tumors of other localizations, it does not become more frequent with age, but reaches its peak in young men of working age what attaches to the problem not only great medical, but also social significance.Estimation of angiogenesis in the tumor is considered as one of the markers for predicting the course of disease, presence of metastases and sensitivity to antitumor antiangiogenic therapy. At the same time, data concerning the study of the mechanisms of blood vessels formation, the work out of methods for estimation of tumorous angiogenesis as well as the use habits of IHC markers of endothelial cells (CD31 and CD34) for assessing the aggressiveness and prognosis of TGCT and, in particular, EC, are absent in the available literature sources.Investigation of peculiarities of neoangiogenesis in the dynamics of testicular embryonal carcinoma progression revealed: significant increasing of relative area of CD31 and CD34 expression as well as vascular density during transition from the initial to the late stages of tumor progression; formation of intratumoral vessels in the embryonal carcinoma occurs by angiogenesis and vasculogenesis with participation of progenitor endothelial cells; embryonal carcinoma is characterized by vasculogenic mimicry in the form of channels formation that do not have endothelial lining

Organization of advocacy in various legal systems: comparative analysis

This article observes organization of providing legal services in different countries, such as the US, the UK, Germany, France, China and Russia. The authors describe the procedure of admitting to the legal profession and the sphere of legal activit

Changes of the body functions during long-term hypokinesia

Prolonged hypokinesis (100-170 days) studied in 2000 rats kept in cages limiting their mobility provoked considerable changes in the gaseous and energetic metabolism: an elevation of the total gaseous metabolism and of the rate of O2 requirement by the muscles (in the late periods of hypokinesis) and a change in the intensity of tissue respiration of the liver and myocardium. There also proved to be a reduction in the level of phosphorylation and separation of oxidative phosphorylation in the myocardium, liver, and partially in the skeletal muscle. Prolonged hypokinesia led to changes in tissue metabolism: a disturbance of development of the animals, a marked delay and an increase in the weight of the organism and the muscular system, and disturbances of the mineral and protein metabolism. Prolonged hypokinesis also lead to exhaustion of the hypothalamus-hypophysis-adrenal cortex system

Synthesis of New Bitopic Tetra(pyrazolyl)-Ligands with Neopentane and O-Xylene Backbones

Several new bitopic pyrazole-containing ligands were prepared from the corresponding pyrazoles and tetrahalogen or tetratosyloxy derivatives of o-xylene and neopentane in a superbasic medium (KOH-DMSO)

Электромагнитная дефектоскопия-толщинометрия многоколонных скважин методом переходных процессов

The transient electromagnetic method is the most effective in the studying of multi-string wells. First, the nonstationary field is measured after the current is turned off (without the primary field) that reduces the coil spacing to zero, i.e. combine the generator and receiver coils. This significantly improves the vertical characteristic of the probe, allows the probe to register small defects. Second, the non-stationary mode allows separating signals from the first, second, third, etc. strings much easier than the harmonic mode. It improves the accuracy of thickness estimation and defect detection. The paper proposes an algorithm for interpreting the measurement results.Метод переходных процессов является наиболее эффективным при исследовании многоколонных скважин. Во-первых, измерение нестационарного поля производится после выключения тока в отсутствие первичного поля, что позволяет сократить разнос катушек до нуля, т.е. совместить генераторную и приемные катушки. А это существенно улучшает вертикальную характеристику зонда, позволяет регистрировать малые дефекты. Во-вторых, при нестационарном режиме значительно проще разделить сигналы от первой, второй, третьей и т.д. колонн, чем при гармоническом режиме, что повышает точность вычисления толщины и определения дефектов. В работе предложен алгоритм интерпретации результатов измерени

Quantum Phase Shift in Chern-Simons Modified Gravity

Using a unified approach of optical-mechanical analogy in a semiclassical formula, we evaluate the effect of Chern-Simons modified gravity on the quantum phase shift of de Broglie waves in neutron interferometry. The phase shift calculated here reveals, in a single equation, a combination of effects coming from Newtonian gravity, inertial forces, Schwarzschild and Chern-Simons modified gravity. However the last two effects, though new, turn out to be too tiny to be observed, and hence only of academic interest at present. The approximations, wherever used, as well as the drawbacks of the non-dynamical approach are clearly indicated.Comment: 16 pages, minor errors corrected. Accepted for publication in Phys. Rev.

Aproximación integral a la evaluación del progreso hacia la sostenibilidad

Traducción: Patricia M. Bartol de lmbachVersión en inglés disponible en la Biblioteca Digital del IDRC: Community-based indicators : a guide for field workers carrying out monitoring and assessment at the community levelVersión en francés disponible en la Biblioteca Digital del IDRC: Indicateurs communautaires : guide à l'intention des travailleurs sur le terrain faisant des travaux de contrôle et d'évaluation communautaire