Social and Psychological Features of Hardiness in Personality of Students of Higher Education Institutions

The topicality and significance of the study is determined by the fact that life and activity of a person in contemporary socio-economic conditions are inextricably connected with the constant impact of adverse social, political, economic and other factors on him. These factors are accompanied by the emergence of various kinds of difficult life situations, as a result of which stress develops in a person. In the student milieu, stress arises under the influence of difficulties associated with both the learning process and life circumstances. The paper presents the results of an empirical study of socio-psychological features of hardiness in students of higher educational institutions. The methods of research comprised: theoretical analysis, empirical research (testing), qualitative analysis of the obtained data, mathematical and statistical data processing (SPSS Statistics, Excel). Testing included the following psycho-diagnostic tools: the author’s questionnaire for assessing stressful situations; McCrae-Costa Five-Factor Personality Questionnaire (The Big Five dimensions); “Hardiness test”; Self-attitude technique. The validity and reliability of the study results was ensured by the initial methodological positions, the use of proven tools, sample representativeness of the research, as well as mathematical processing of data with the use of a software package for statistical analysis. As a result of the study, it was proved that emotion-focused ways of overcoming stress associated with a decrease in tension and a change in attitude to emerging difficulties prevail among the students of both the experimental and control groups. A high level of stress was found in the majority of subjects. In order to reduce this stress, it is necessary for students to form special skills to overcome it. In addition, an analysis of the psychological factors of students’ hardiness made it possible to determine the main areas of their psychological support in overcoming difficult life situations (development of qualities that form the core of students’ personal adaptive potential, the formation of their social competency, enrichment of social networks, as well as learning ways to find and accept social support)

On the escape of cosmic rays from radio galaxy cocoons

(Abridged) A model for the escape of CR particles from radio galaxy cocoons is presented here. It is assumed that the radio cocoon is poorly magnetically connected to the environment. An extreme case of this kind is an insulating boundary layer of magnetic fields, which can efficiently suppress particle escape. More likely, magnetic field lines are less organised and allow the transport of CR particles from the source interior to the surface region. For such a scenario two transport regimes are analysed: diffusion of particles along inter-phase magnetic flux tubes (leaving the cocoon) and cross field transport of particles in flux tubes touching the cocoon surface. The cross field diffusion is likely the dominate escape path, unless a significant fraction of the surface is magnetically connected to the environment. Major cluster merger should strongly enhance the particle escape by two complementary mechanisms. i) The merger shock waves shred radio cocoons into filamentary structures, allowing the CRs to easily reach the radio cocoon boundary due to the changed morphology. ii) Also efficient particle losses can be expected for radio cocoons not compressed in shock waves. There, for a short period after the sudden injection of large scale turbulence, the (anomalous) cross field diffusion can be enhanced by several orders of magnitude. This lasts until the turbulent energy cascade has reached the microscopic scales, which determine the value of the microscopic diffusion coefficients.Comment: A&A in press, 12 pages, 5 figures, minor language improvement

On the shape of the spectrum of cosmic-rays accelerated inside superbubbles

Supernova remnants are believed to be a major source of cosmic-rays in the Galaxy. As their progenitors are commonly found clustered in OB associations, one has to consider the possibility of collective effects in the acceleration process. In this work we investigate the shape of the spectrum of protons accelerated inside the superbubbles blown around clusters of massive stars. To do so we embed semi-analytical models of particle acceleration and transport inside Monte-Carlo simulations of OB associations timelines. We consider regular acceleration at the shock front of supernova remnants, as well as stochastic re-acceleration and escape occurring between the shocks. We observe that particle spectra, although strongly intermittent, get a distinctive shape resulting from a competition between acceleration and escape: they are harder at the lowest energies and softer at the highest energies. The momentum at which this spectral break occurs depends on a single dimensionless parameter, which we evaluate for a selection of objects. The behaviour of a superbubble regarding acceleration depends on the magnetic turbulence: if B is low the superbubble is simply the host of a collection of individual supernovae shocks, but if B is high enough it acts as a global accelerator, producing distinctive spectra ? which has important implications on the high-energy emission from these objects.Comment: accepted for publication in A&A (final version

Superbubbles and Energetic Particles in the Galaxy. I: Collective effects of particle acceleration

Observations indicate that most massive stars in the Galaxy appear in groups, called OB associations, where their strong wind activity generates large structures known as superbubbles, inside which the subsequent supernovae (SNe) explode, in tight space and time correlation. Acknowledging this fact, we investigate four main questions: 1) does the clustering of massive stars and SN explosions influence the particle acceleration process usually associated with SNe, and induce collective effects which would not manifest around isolated supernova remnants?; 2) does it make a difference for the general phenomenology of Galactic Cosmic Rays (GCRs), notably for their energy spectrum and composition?; 3) can this help alleviate some of the problems encountered within the standard GCR source model?; and 4) Is the link between superbubbles and energetic particles supported by observational data, and can it be further tested and constrained? We argue for a positive answer to all these questions. Theoretical, phenomenological and observational aspects are treated in separate papers. Here, we discuss the interaction of massive stellar winds and SN shocks inside superbubbles and indicate how this leads to specific acceleration effects. We also show that due to the high SN explosion rate and low diffusion coefficient, low-energy particles experience repeated shock acceleration inside superbubbles.Comment: 14 pages, accepted for publication in A&

BIOMECHANICAL STUDY OF SINGLE ROOTED TEETH RESTORED WITH DOWEL CORS

The purpose of the biomechanical study was a comparative analysis of the stress-strain state of the dowel core, dentin of the tooth root, periodontal and bone tissues of the alveolus in the restoration of the first premolars using dowel core, made of zirconium oxide. Materials and methods. Mathematical modeling was carried out using a service modeling and finite element analysis NASTRAN, designed for implementation on a personal computer in a Windows environment. The package, which is built and analyzed considers an elastic three-dimensional models of dental arches on the basis of finite-element procedures, determines the displacement of each node of the finite element with three axes, the normal and shear stresses, and equivalent stresses according to Huber-Mises, which are calculated according to the formula of mechanics of solid deformable body. Teeth with dowel core are located relative to the coordinate axes that the z axis coincides with the longitudinal axis of the tooth, the x-axis in a distal-medial direction (along the tooth row) and the y-axis in the oral-vestibular (in the perpendicular direction of the dentition). As a main evaluation criterion when comparing the stress-strain state of considered mathematical models of the system "dowel core- recovery single rooted tooth - lower jaw" should take the maximum values of equivalent stresses in the dowel core and the dentin of the root part of the tooth recoverable, arising from the action of the calculated values of functional loads , since exceeding these tension can cause destruction of the root of the tooth or core. As additional evaluation criteria appropriate to compare the maximum values of the equivalent stresses in the adjacent to the root portion of the restored tooth in the periodontium, cortical and trabecular layers of the jawbone. As a result of mathematical analysis of a model system “the root of the tooth, dowel core, crown” found that the horizontal component of the functional load and the combined effect of vertical and horizontal components of the load leads to the localization of fields of maximum values of equivalent stresses in the middle third of the pin of the dowel core from the vestibular or oral side, depending on the direction of the horizontal load. In cases where only the vertical component of the maximum load values of the equivalent stresses occur in the zone of junction of the coronal part of the dowel core to pin. The maximum values of the equivalent stresses in the restored tooth and the periodontal and dowel core arise under the combined action of the vertical component of the functional load from the horizontal, directed in the vestibular- lingual direction. The most dangerous area of the root of the tooth from the point of view of localization of maximum values of equivalent stresses is in the area of dentin adjacent to the end portion of the pin. When restoring the coronal portion of premolar using dowel core maximum values of the equivalent stresses in all structural components of the examined bone tissue does not exceed the corresponding values of ultimate strength, the presence and design of the dowel core significantly affect the values of the equivalent stresses in the dentin of the tooth root, and has almost no effect on stresses in the periodontal and bone tissues of the lower jaw; the localization of the fields of maximum values of equivalent stress on the surface of the root portion of the dentin in the tooth a healthy load corresponds to the location and the value of the equivalent stress tooth under load which restores; the most unfavourable loading is the combined effect of the vertical component of the functional load and the horizontal component, targeted in vestibular- lingual direction