Mathematical modeling of solidification process near the inner core boundary of the Earth

Radially symmetric analytic solutions of the heat and mass transfer equations governing convection in the Earth's fluid core are found in terms of deviations from the adiabatic reference state. We demonstrate that an increase of the convective velocity leads to a decrease of the light constituent mass fraction and specific entropy. Where fluid is rising/descending, convective motions decrease/increase the mass fraction and entropy at the inner core boundary (ICB). The influence of convective motions on the thermal fluxes at the core mantle boundary is studied. On the basis of exact solutions we demonstrate that the liquid is supercooled near the ICB. An important point is that an increase in the convective velocity directed to the ICB increases the constitutional supercooling. We show that the anelastic model (AM) can be used only at small supercoolings near the ICB. The most probable solidification scenario "constitutional supercooling and morphological instability" should be described by a mushy layer theory near the ICB and by the AM in the rest region of the fluid outer core. On the basis of dendritic theory and selection mechanisms of crystal growth the dendrite tip radius and interdendritic spacing in the mushy layer at the ICB are determined in the presence of convection. © 2013 Elsevier Inc

Conditioned Unitary Transformation on biphotons

A conditioned unitary transformation ($90^o$ polarization rotation) is performed at single-photon level. The transformation is realized by rotating polarization for one of the photons of a polarization-entangled biphoton state (signal photon) by means of a Pockel's cell triggered by the detection of the other (idler) photon after polarization selection. As a result, polarization degree for the signal beam changes from zero to the value given by the idler detector quantum efficiency. This result is relevant to practical realization of various quantum information schemes and can be used for developing a new method of absolute quantum efficiency calibration

Sea Ice Dynamics Induced by External Stochastic Fluctuations

The influence of stochastic fluctuations in the atmosphere and in the ocean caused by different occasional phenomena (noises) on dynamic processes of sea ice growth with a mushy layer is studied. It is shown that atmospheric temperature variances substantially increase the sea ice thickness, whereas dispersion variations of turbulent flows in the ocean to a great extent decrease the ice content produced by false bottom evolution. © 2013 Springer Basel

Design and evaluation of pharmacological properties of a new 1,3,4-thiadiazolylamide derivative of 2-propylpentanoic acid

The use of the pharmacophoric approach is a promising direction for modifying the chemical structure of 2-propylpentanoic (valproic) acid in order to obtain new drug

Solidification dynamics under random external-temperature fluctuations

The nonlinear dynamic mechanisms of solid-phase formation with a phase transition region are studied under periodic and random fluctuations of the cooling-boundary temperature. It is theoretically shown that a mushy zone can form even at close liquid and cooling-boundary temperatures due to random temperature field fluctuations. The growth of a solid phase with the mushy zone is investigated as a function of the autocovariance characteristics of random noises. © 2013 Pleiades Publishing, Ltd

Сross-analysis of big data in accreditation of health specialists

Objective: The relevance of this study is due to the mass accreditation of health professionals that is developing in Russia, which requires innovative measurement tools and opens new opportunities for a well-founded cross-analysis of specialists’ professional readiness quality. Purpose of the study: The purpose of this article is to present approved methodical approaches to the transformation of accreditation data into a format suitable for secondary analysis of medical schools graduates quality based on the requirements of Professional Standards. Method: The leading methods of secondary data analysis are: a) codification of indicators in the primary data accumulation array; b) statistical processing of study results (evaluation of the relationships between the arrays of primary data accumulation and instrumental data, the correlation of test scores obtained by accreditation results with the labor functions of Professional Standards); c) the creation of representative samples for data analysis. The implementation of methods is carried out in the mode of working with arrays of big data, which also uses the method of cross-analysis to identify additional factors that affect to specialists’ professional readiness quality. Results: As a results of the research, there were: 1) approaches to the codification of data in the array and their secondary analysis were developed; 2) three samples were constructed with an estimation of representativeness for different strata, including subjects, assignments and corresponding labor functions; 3) the matrix of primary data in the specialty “Pediatrics” was verified using the example of the results of students from 50 medical universities in Russia. Conclusion: Approbation of methods of secondary data analysis conducted on representative samples of the subjects showed the effectiveness of the developed approaches that should be used when analyzing large data sets in the procedures of certification or accreditation. The materials of the article can be useful for specialists in the field of assessing the quality of education or assessing the professional readiness of health professionals, managers, professors and pedagogical staff of medical schools, specialists of centers for independent assessment of qualifications. © 2018, Modestum Ltd.. All rights reserved

Psychological features and social adaptation of internet-addicted adolescents and adolescents with cannabinoid addiction

The Objective of the research is to study the characteristics of character properties, emotional intelligence, social psychological adaptation of Internet addicted adolescents and adolescents addicted with drugs. Design. A comparative study of the psychological properties of cannabinoid addicted adolescents (n = 20) and Internet addicted adolescents (n = 20), and also healthy adolescents without symptoms of addiction (n = 20) is conducted. The following methods are used in the study: Barratt’s impulsiveness scale (BIS-11), 1987, adapted by T.I. Medvedeva and S.N. Enikolopov, 2015, Cloninger temperament and character questionnaire (TCI-125), 1991, adapted by N.A. Almaev and L.D. Ostrovskaya, 2005, the methodology for diagnosing emotional intelligence MSCEITV 2.0 2002, adapted by E.A. Sergienko, N.I. Vetrova, 2009, the methodology for diagnosing the social psychological adapted by K. Rogers and R. Diamond, 1954, adapted by A.K. Osnitsky, 2002, Chen Internet Addiction Scale (CIAS), 2003 adapted by V.L. Malygin and K.A. Feklisov, 2010 Results. Adolescents with Internet addiction and adolescents with cannabinoid addiction have a certain similarity in a number of characteristic features. They are characterized by a more pronounced motor impulsiveness, low self-control, low self-esteem, dependence on other individulas and circumstances, lack of clear life goals. In general, if compared to healthy adolescents they appear to be infantile individuals, socially maladjusted, more often experiencing emotional discomfort, which can result in pathologies, i.e. particularly various types of addictive behaviour. Simultaneously, Internet-dependent adolescents are significantly different from those with cannabinoid addiction. They are characterized by a lower level of transcendence and a lesser inclination to spiritual practices and transpersonal experience accordingly. They have a low level of search for novelty, which characterizes them as conservative, rigid and passive individuals. Conclusion. The data obtained reveal certain differences in the psychological mechanisms of Internet addiction and dependence on drugs. Psychological mechanisms of adolescent Internet addiction and dependence on cannabinoids have significant differences

Simple Chemical Method for the Determination of Carbon Dioxide in Air

The determination of carbon dioxide in air was always an important practical problem. It became particularly important in recent decades because of the studies of the greenhouse effect Because of difficulties in the direct detection of the equivalence point for the interaction of low concentrations of CO 2 with reagents, the two-step titration method is most frequently used among chemical methods for the determination of CO 2 . Within this method, first an aliquot portion of a solution of barium hydroxide of known concentration is partially neutralized with carbon dioxide contained in a known volume of air, and next residual Ba(OH) 2 is titrated with a reference solution of acid Known instrumental methods In this work, we propose a chemical method for the determination of CO 2 in air, which differs from the method mentioned above by a lower cost and simple implementation, being highly competitive with them in accuracy. The method is based on the detection of the equivalence point in the neutralization of an aqueous solution of Ba(OH) 2 by CO 2 contained in air by measuring the electrical conductance of the solution. The accurate detection of the equivalence point in this case is caused by the fact that CO 2 interacts with Ba(OH) 2 in two reactions proceeding successively [9]: Ç ‡ +2 + 2éç -+ ëé 2 = Ç ‡ëé 3 ↓ + ç 2 é, Ç ‡ëé 3 + ëé 2 + ç 2 é = Ç ‡ 2+ + . From the equations of the reactions, it follows that, at the first step of CO 2 absorption, barium and hydroxyl ions are removed from the solution because of the formation of a barium carbonate precipitate, which leads to a decrease in the electrical conductance of the solu- Abstract -A method was proposed for the direct determination of carbon dioxide in air using a sorption tube specially constructed for this purpose. The method is based on measuring the volume of air consumed for the neutralization of a known amount of barium oxide hydrate in the tube by carbon dioxide contained in air. The equivalence point is detected by the minimum electrical conductance of the barium hydroxide solution. To verify the accuracy of the method, a technique based on the use of a calibration mixture of air with the CO 2 concentration varying by the inverse exponential law was developed. The method is suitable for the determination of CO 2 in air in a wide concentration range and for the verification and calibration of indirect methods for the determination of CO 2 . With an insignificant decrease in accuracy, the equivalence point can be detected by the change in the color of phenolphthalein. This significantly simplifies the method and allows its wide use in practice, e.g., in laboratory works in environmental science or for demonstration purposes in educational organizations