Numerical simulation of helical-vortex effects in Rayleigh-Bénard convection

International audienceA numerical approach is substantiated for searching for the large-scale alpha-like instability in thermoconvective turbulence. The main idea of the search strategy is the application of a forcing function which can have a physical interpretation. The forcing simulates the influence of small-scale helical turbulence generated in a rotating fluid with internal heat sources and is applied to naturally induced fully developed convective flows. The strategy is tested using the Rayleigh-Bénard convection in an extended horizontal layer of incompressible fluid heated from below. The most important finding is an enlargement of the typical horizontal scale of the forming helical convective structures accompanied by a cells merging, an essential increase in the kinetic energy of flows and intensification of heat transfer. The results of modeling allow explaining how the helical feedback can work providing the non-zero mean helicity generation and the mutual intensification of horizontal and vertical circulation, and demonstrate how the energy of the additional helical source can be effectively converted into the energy of intensive large-scale vortex flow

Variasi Mutu Fisiologis Benih dan Pertumbuhan Bibit Sengon dari Beberapa Provenan Asal Papua

Exploration of sengon across Papua was resulted in collection of seeds from various provenances. This research aims to determine physiological seed quality and seed growth of Falcataria moluccana from various provenances in Papua. It consisted of two experiments. The first experiment used 8 provenances with 20 replications. In each replication 1 gram of seed was used. The rate, percentage and value of germination were observed. The second experiment used 8 provenances with 5 replications. Each replication consists of 20 seedlings. Seedling height and diameter were observed. Results demonstrated that provenance origin significantly affected seed physiological quality of F. moluccana. Germination percentage was well performed by provenance from Meagama (Wamena) with germination rate at 87.14% well performed by provenance from Wadapi Menawi (Serui) by 17.35%/etmal and germination value was well performed by Elagaima at 3.69, consecutively. It also significantly affected seedling growth after 3 months at the nursery. Provenance showing the best growth in height and diameter was Meagama (Wamena) at 29.29 cm and 2.61cm, respectively

Ramped-induced states in a parametrically driven Ginzburg-Landau equation

We introduce a parametrically driven Ginzburg-Landau (GL) model, which admits a gradient representation, and is subcritical in the absence of the parametric drive (PD). In the case when PD acts uniformly in space, this model has a stable kink solution. A nontrivial situation takes places when PD is itself subject to a kink-like spatial modulation, so that it selects real and imaginary constant solutions at +infinity and -infinity. In this situation, we find stationary solutions numerically, and also analytically for a particular case. They seem to be of two different types, viz., a pair of kinks in the real and imaginary components, or the same with an extra kink inserted into each component, but we show that both belong to a single continuous family of solutions. The family is parametrized by the coordinate of a point at which the extra kinks are inserted. Solutions with more than one kink inserted into each component do not exist. Simulations show that the former solution is always stable, and the latter one is, in a certain sense, neutrally stable, as there is a special type of small perturbations that remain virtually constant in time, rather than decaying or growing (they eventually decay, but extremely slowly).Comment: A latex text file and 8 ps files with figures. Physics Letters A, in pres

Влияние функциональной взаимосвязи понятия, образа и действия на процесс решения междисциплинарных технологически ориентированных задач

This article studies the influence of the methods used by students to solve tasks on the effectiveness of the learning process based on their analysis. The study has revealed that mastering the combined method based on the functional relationship between concept, image and action in the process of solving interdisciplinary technological tasks is one of the mechanisms of effective preparation of students for professional activity in the labour market of related professions.En este artículo, basado en un análisis de los métodos utilizados por los estudiantes para resolver problemas, se investiga su influencia en la efectividad del proceso de aprendizaje. En el curso del estudio, se reveló que el dominio del método combinado, basado en la relación funcional del concepto, la imagen y la acción, en el proceso de resolución de problemas tecnológicos interdisciplinarios es uno de los mecanismos para la preparación efectiva de los estudiantes para actividades profesionales en el contexto de la aparición de profesiones relacionadas en el mercado laboral.В данной статье на основе анализа используемых обучающимися способов решения задач исследуется их влияние на результативность процесса обучения. В процессе исследования выявлено, что владение комбинированным способом, основанном на функциональной взаимосвязи понятия, образа и действия, в процессе решения междисциплинарных технологических задач выступает одним из механизмов эффективной подготовки обучающихся к профессиональной деятельности в условиях появления на рынке труда смежных профессий

Modelling of large-scale structures arising under developed turbulent convection in a horizontal fluid layer (with application to the problem of tropical cyclone origination)

International audienceThe work is concerned with the results of theoretical and laboratory modelling the processes of the large-scale structure generation under turbulent convection in the rotating-plane horizontal layer of an incompressible fluid with unstable stratification. The theoretical model describes three alternative ways of creating unstable stratification: a layer heating from below, a volumetric heating of a fluid with internal heat sources and combination of both factors. The analysis of the model equations show that under conditions of high intensity of the small-scale convection and low level of heat loss through the horizontal layer boundaries a long wave instability may arise. The condition for the existence of an instability and criterion identifying the threshold of its initiation have been determined. The principle of action of the discovered instability mechanism has been described. Theoretical predictions have been verified by a series of experiments on a laboratory model. The horizontal dimensions of the experimentally-obtained long-lived vortices are 4÷6 times larger than the thickness of the fluid layer. This work presents a description of the laboratory setup and experimental procedure. From the geophysical viewpoint the examined mechanism of the long wave instability is supposed to be adequate to allow a description of the initial step in the evolution of such large-scale vortices as tropical cyclones - a transition form the small-scale cumulus clouds to the state of the atmosphere involving cloud clusters (the stage of initial tropical perturbation)

Self-organization without conservation: Are neuronal avalanches generically critical?

Recent experiments on cortical neural networks have revealed the existence of well-defined avalanches of electrical activity. Such avalanches have been claimed to be generically scale-invariant -- i.e. power-law distributed -- with many exciting implications in Neuroscience. Recently, a self-organized model has been proposed by Levina, Herrmann and Geisel to justify such an empirical finding. Given that (i) neural dynamics is dissipative and (ii) there is a loading mechanism "charging" progressively the background synaptic strength, this model/dynamics is very similar in spirit to forest-fire and earthquake models, archetypical examples of non-conserving self-organization, which have been recently shown to lack true criticality. Here we show that cortical neural networks obeying (i) and (ii) are not generically critical; unless parameters are fine tuned, their dynamics is either sub- or super-critical, even if the pseudo-critical region is relatively broad. This conclusion seems to be in agreement with the most recent experimental observations. The main implication of our work is that, if future experimental research on cortical networks were to support that truly critical avalanches are the norm and not the exception, then one should look for more elaborate (adaptive/evolutionary) explanations, beyond simple self-organization, to account for this.Comment: 28 pages, 11 figures, regular pape

UNIVERSITY INTELLECTUAL CAPITAL FORMATION AND DEVELOPMENT

Purpose of the study: One of the most important terms to solve the problems of the education system is the educational institution’s intellectual capital, which significantly transforms the role and functions of the modern educator. The purpose of the article is to identify the essence of the University's intellectual capital and to justify the trajectory of its development, due to the needs and capabilities of education stakeholders. Methodology: Based on the methodology of education quality management the article justifies the leading role of quality education as an imperative of the University development. Intellectual capital is considered from the standpoint of organizational resources that determine the cost of the final product – the quality of education and the competitive position of the University; its development is carried out based on the project-target approach. Results: Modern requirements for the intellectual capital of the educational organization are revealed, the role and essence of pedagogical activity of teachers of higher education institutions in its formation are shown. The importance of continuous improvement of hard and soft competencies of University teachers as a way of incrementing intellectual capital is shown. The adaptive model’s design of University teachers’ career strategies based on design-target mechanisms is presented that determines the organizational development of the University. Applications of this study: The results determined the possibility to consider organizational and human knowledge and competence as a special type of investment to improve the functioning of the University. The recommendations for the construction of models of the University intellectual capital management are presented. The article is intended for employees of the education system, educators, researchers, and heads of the University departments. Novelty/Originality of this study: The contribution is made to the theory of the University’s social and cognitive management based on expanding the powers of quality management in the field of intellectual capital management

Efficiency management of educational systems development: Approaches and criteria

© 2016, Econjournals. All rights reserved.The relevance of the study is reasoned by the need to assess the ongoing educational reforms’ implementation, to identify effective strategies, models, mechanisms and technologies. The aim of the paper is to determine the expected criteria and obtained results’ efficiency of the systems’ operation in conditions of high variability of external and internal environment. The paper describes the variety of cycles of the educational system on the example of university training that involves the principle of iteration using in educational development’s management. The authors present certain criteria for management of educational development from the standpoint of functional efficiency of the system defining the management contour of development’s efficiency. This paper is intended for researchers and specialists in the field of educational management at all levels

Diagnostics and therapy of peripheral neuropathy (literature review)

The review is devoted to diagnostics and treatment of neuropathic pain in patients with peripheral nervous system diseases. Main assessment tools are shown including Visual analog Scale (VAS), Neuropathic Pain Scale (NPS), Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), self-report version of the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), Neuropathic Pain Questionnaire (NPQ), Questionnaire Douleur Neuropathique 4 (DN-4), pain DETECT Questionnaire, Standardized Evaluation of Pain (StEP), identification pain questionnaire (ID-pain), clinical investigation (quantitative sensorial test are included), neurophysiological studies (electroneuromyography, evoked potentials) and MRI. Novel therapy in neuropathic pain disorders is described including both medicamentous and additional therapeutics methods