Numerical study of the Rosensweig instability in a magnetic fluid subject to diffusion of magnetic particles

The present study is devoted to the classical problem on stability of a magnetic fluid layer under the influence of gravity and a uniform magnetic field. A periodical peak-shaped stable structure is formed on the fluid surface when the applied magnetic field exceeds a critical value. The mathematical model describes a single peak in the pattern assuming axial symmetry of the peak shape. The field configuration in the whole space, the magnetic particle concentration inside the fluid and the free surface structure are unknown quantities in this model. The unknown free surface is treated explicitly, using a parametric representation with respect to the arc length. The nonlinear problem is discretized by means of a finite element method for the Maxwell's equations and a finite-difference method for the free surface equations. Numerical modeling allows to get overcritical equilibrium free surface shapes in a wide range of applied field intensities. Our numerical results show a significant influence of the particle diffusion on the overcritical shape

Equilibrium shapes of a ferrofluid drop

A numerical solution strategy for calculating equilibrium free surfaces of a ferrofluid drop under the action of uniform magnetic fields is proposed. Based on this strategy, drop shapes of nonlinear magnetizable fluids are obtained numerically in a wide range of field intensities and compared with existing theoretical result

Behavioural Characteristics of Children with Developmental Disorder Risks

The article is devoted to the study of the temperament and behaviour of children with developmental disorder risks. Early age is most significant in terms of early identifying deviant development markers for implementing effective programmes for early intervention. The article deals with the peculiarities of using the Infant Behaviour Questionnaire - Revised (IBQ-R) and its application in scientific research; the results of domestic and foreign research into temperament as a marker/predictor of deviant behaviour are presented. The paper describes the results of a pilot study of differences in behaviour in a sample of 49 children aged 5.6 months. The research involved two groups of test children, a reference group (typically developing children) and the children of developmental risk groups (which included prematurity, family risk of autism spectrum disorders (ASD)/attention deficit and hyperactivity disorder (ADHD), paediatric arterial ischemic stroke). The significant impact of developmental disorder risks on the Perceptual Sensitivity Scale (IBQ-R) as well as the effect of sexand risks on the Approach, Vocal Reactivity (IBQ-R) scale were discovered. There are suggestions that prematurity may have a negative impact on the development of temperament in children aged 6 months. However, in comparison with such factors as the genetic predisposition to atypical development or local brain damage due to paediatric arterial ischemic stroke, prematurity (excluding extremely premature) probably has less influence on the development of temperament and behavioural characteristics. There is a significant heterotypic continuity of individual differences in temperament indicators at an early age, which highlights the need for further research into the issue and the formation of large cohorts of children. Keywords: deviant development markers, behaviour, IBQ-R questionnaire

Numerical modeling of the equilibrium shapes of a ferrofluid drop in an external magnetic field

A numerical solution strategy for calculating equilibrium free surfaces of a magnetic fluid under the action of a magnetic field is proposed and applied to determine shapes of a linear magnetizable ferrofluid drop in a uniform magnetic field. Hysteresis phenomena for the drop deformation and the drop shapes with ends, close to conical, were observed numericall

THE MARKETING ANALYSIS AS THE MECHANISM OF INCREASE IN COMPETITIVE ADVANTAGES OF THE ENTERPRISE IN THE BRANCH MARKET

In article it is proved that the main directions of marketing activity of the enterprises in modern economy combine lines of economic, financial, planned, production, marketing and research work. In the general structure of marketing by authors marketing of research and development, marketing of goods and services, marketing of means of production, marketing of material resources, import and export marketing, marketing of financial and investment activity, marketing of social development is allocated

Numerical treatment of free surface problems in ferrohydrodynamics

The numerical treatment of free surface problems in ferrohydrodynamics is considered. Starting from the general model, special attention is paid to field-surface and flow-surface interactions. Since in some situations these feedback interactions can be partly or even fully neglected, simpler models can be derived. The application of such models to the numerical simulation of dissipative systems, rotary shaft seals, equilibrium shapes of ferrofluid drops, and pattern formulation in the normal-field instability of ferrofluid layers is given. Our numerical strategy is able to recover solitary surface patterns which were discovered recently in experiment

THE MARKETING ANALYSIS AS THE MECHANISM OF INCREASE IN COMPETITIVE ADVANTAGES OF THE ENTERPRISE IN THE BRANCH MARKET

In article it is proved that the main directions of marketing activity of the enterprises in modern economy combine lines of economic, financial, planned, production, marketing and research work. In the general structure of marketing by authors marketing of research and development, marketing of goods and services, marketing of means of production, marketing of material resources, import and export marketing, marketing of financial and investment activity, marketing of social development is allocated