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

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

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

Определение характеристик конечных участков стандартных маршрутов прибытия с помощью аппарата системы массового обслуживания

The article solves the problem of determining the probabilistic characteristics of the STARs legs which specify a sequencing technique of “point merge” and “trombone”-type considering the intensity of the air traffic flow and the formation of a queue. This task is closely related to the airspace efficiency, as well as to the limit values of flight safety performance. An application of the queueing system makes it possible to optimize the elements of the airspace structure on an objective basis, and in the event of considering the inverse problem to establish limit values for the air traffic flow characteristics. The characteristics of the “point merge” and “trombone”-type schemes become of prime importance in the air hub, where several airfields function of each other in a relatively small volume of airspace – as it happens in the Moscow air hub, so it is the given hub that is taken as a practical example. In this problem the basic model is the queueing system with limited-size queues where the optimal number of service channels in a stationary air traffic flow is determined in a probabilistic way. The stated model encapsulates the essence of the “trombone” or “point merge”-type scheme, where the number of service channels corresponds to the number of flight levels on the arc of the “point merge” or on the horizontal flight segment of the “trombone”. Now, the number of such flight levels, as a rule, corresponds to the number of standard arrival routes involved in the formation of a “trombone” (“point merge”), which, from a practical point of view, is excessive. The task of using the mathematical apparatus of the queueing system is to determine the optimal number of flight levels – service channels of the model while establishing the required probability of its failure. As a mathematical model of the queueing system, the “trombone”-type scheme is used, and in the mentioned above example, the structure of the airspace is presented using the “point merge”-type scheme as a regulator of the aircraft sequence for landing. All the computations are performed for the certain intensity of air traffic flow for a specified airfield, considering the full-scale application of continuous descent operations and continuous climb operations (CDO, CCO). As a result of solving the problem, the value for the optimal number of flight levels on the “trombone” or “point merge”-type scheme was obtained, and the dependence of the number of service channels (flight levels on the “trombone” or “point merge”) on the value of the given probability of the queueing system failure was shown. The proposed approach to the airspace structure formation has prospects for implementation.В статье решается задача определения вероятностных характеристик участков стандартных маршрутов прибытия, определяющих порядок построения очереди на посадку типа «веер» и «тромбон», с учетом интенсивности потока движения воздушных судов и размера возникающей очереди. Данная задача тесно связана с эффективностью использования воздушного пространства, а также с предельными значениями характеристик безопасности полетов. Применение аппарата системы массового обслуживания позволяет оптимизировать элементы структуры воздушного пространства на объективной основе, а в случае рассмотрения обратной задачи установить предельные значения характеристик потока воздушного движения. Особую значимость характеристики схем типа «веер» и «тромбон» приобретают в аэроузле, где в относительно небольшом объеме воздушного пространства, независимо друг от друга функционируют несколько аэродромов. Так происходит в московском аэроузле, поэтому именно этот узел принят в качестве практического примера. Как базовая модель в данной задаче рассматривается система массового обслуживания с очередями ограниченного размера, где вероятностным способом производится поиск оптимального количества каналов обслуживания в стационарном потоке воздушного движения. Такая модель определяет суть схемы типа «тромбон» или«веер», где количество каналов обслуживания соответствует количеству эшелонов на дуге веера или на участке горизонтального полета тромбона. На настоящий момент количество таких эшелонов, как правило, соответствует количеству стандартных маршрутов прибытия, участвующих в формировании тромбона (веера), что с практической точки зрения является избыточным. Задача использования математического аппарата системы массового обслуживания состоит в определении оптимального количества эшелонов – каналов обслуживания модели при установлении требуемой вероятности ее отказа. В качестве математической модели системы массового обслуживания применена схема типа«тромбон», а в приведенном примере представлена структура воздушного пространства с применением схемы типа«веер» в качестве регулятора очереди воздушных судов на посадку. Все расчеты произведены для определенной интенсивности потока воздушного движения на конкретный аэродром с учетом полноценного применения режимов постоянного снижения и набора (CDO, CCO). В результате решения задачи получено значение оптимального количества эшелонов на схеме типа «тромбон» или «веер», а также показана зависимость количества каналов обслуживания (эшелонов на тромбоне или веере) от значения заданной вероятности отказа системы массового обслуживания. Предлагаемый подход к организации структуры воздушного пространства имеет перспективы внедрения

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

Методика поддержания целостности потока прибытия на основе характеристик режима постоянного снижения

The article deals with the technique of constructing standard arrival routes using the CDO profile in the airspace of the "approach" zone with increased air traffic intensity. The methodology for calculating the effective values of airspace structure elements is based on the probabilistic characteristics of the arrival flow, on the basis of which the required working areas of the «trombone» and «point merge» are determined in an iterative way in order to maintain the CDO regime. As a result of the application of this technique, an exemplary structure is presented from three standard arrival routes for Sheremetyevo Airport, in which trombones are used on the final sections of the arrival route. The calculation of the probabilistic characteristics of the unimportant functioning of a «trombone» («point merge») is made proceeding from the Poisson law of the arrival flow of the aircraft for each route and the uniform distribution of the random value of the aircraft entry of all routes to an elementary common segment (l). A comparative evaluation of the efficiency of the “trombone” and “point merge” circuits on the working area is made on the basis of the characteristics of the aircraft traffic flow. An important result is obtained, mainly on the “trombone” type, not only on the efficiency of airspace use, but also on the integrity characteristics of the aircraft arrival required for CDO. The obtained results are confirmed by the simulation carried out under the conditions of the problem. In conclusion, the conditions for the practical provision of a constant reduction regime at CDO sections of the standard arrival routes are presented, which includes the exceedance of the calculated ATM, and measures are proposed to minimize the negative consequences from such disturbances of the incoming flow.В статье рассматривается методика построения стандартных маршрутов прибытия с использованием профиля постоянного снижения (CDO) в воздушном пространстве зоны «подхода» с повышенной интенсивностью воздушного движения. Методика расчета эффективных значений элементов структуры воздушного пространства основана на вероятностных характеристиках потока прибытия, на основе которых итерационным способом определяются необходимые рабочие площади «тромбона» и «веера» в целях поддержания режима полета при постоянном снижении. В качестве результата применения указанной методики представлена примерная структура из трех стандартных маршрутов прилета в аэропорт Шереметьево, в которой на конечных участках маршрута прибытия применены «тромбоны». Расчет вероятностных характеристик бесприоритетного функционирования «тромбона» («веера») произведен исходя из пуассоновского закона потока поступления воздушных судов (ВС) на каждый маршрут и равномерного распределения случайной величины попадания ВС всех маршрутов на элементарный их общий участок (l). Проведена сравнительная оценка эффективности схем «тромбона» и «веера» по рабочей площади на основе характеристик потока движения воздушных судов. Получен существенный результат по преимуществу схемы типа «тромбон» не только относительно эффективности использования воздушного пространства, но и по характеристикам целостности прилетного потока воздушных судов, необходимого для применения CDO. Полученные результаты подтверждены проведенным моделированием в рамках условий задачи. В заключение статьи обозначены условия практического обеспечения режима постоянного снижения на участках CDO стандартных маршрутов прилета, в том числе при превышении расчетной интенсивности воздушного движения, предложены меры по минимизации отрицательных последствий от подобных возмущений прилетного потока