Teaching Quality Assurances in Higher Education Institution: Competence-Based Approach

Use of research methods (analytic and synthetic, modeling, studying of psychology and pedagogical literature and products of activity) allowed researchers of the study to prove relevance of a problem of providing quality assurance of teaching in higher education institution on the basis of competence-based approach to be defined in concept of teaching quality assurance system to develop mechanisms, means, conditions, model of system realization. As the bases for development of teaching quality assurance system realization model the grounds of competence-based approach, the increasing requirements of the state, society, family and personality to education quality, their dissatisfaction with speed and adequacy of the happening changes ac

From optical spectra to phase diagrams — the binary mixture N2–CO

We investigated the T–c% phase diagram of the binary system N2–CO. From changes in IR spectra of all kinds of mode excitations (phonons, vibrons) we were able to determine the temperature of phase transitions (solid–solid, solid–liquid). The improvements in comparison to structural investigations by x-rays or electrons are the following: sample growing and handling with perfect optical and thermodynamic quality; determination of actual concentration (N2)x(CO)y from optical spectra; reduction of thermal hysteresis by careful cooling–heating cycles of the samples

Thyroid cancer risk in Belarus among children and adolescents exposed to radioiodine after the Chornobyl accident

BACKGROUND: Previous studies showed an increased risk of thyroid cancer among children and adolescents exposed to radioactive iodines released after the Chornobyl (Chernobyl) accident, but the effects of screening, iodine deficiency, age at exposure and other factors on the dose-response are poorly understood. METHODS: We screened 11 970 individuals in Belarus aged 18 years or younger at the time of the accident who had estimated (131)I thyroid doses based on individual thyroid activity measurements and dosimetric data from questionnaires. The excess odds ratio per gray (EOR/Gy) was modelled using linear and linear-exponential functions. RESULTS: For thyroid doses \u3c5 \u3eGy, the dose-response was linear (n=85; EOR/Gy=2.15, 95% confidence interval: 0.81-5.47), but at higher doses the excess risk fell. The EOR/Gy was significantly increased among those with prior or screening-detected diffuse goiter, and larger for men than women, and for persons exposed before age 5 than those exposed between 5 and 18 years, although not statistically significant. A somewhat higher EOR/Gy was estimated for validated pre-screening cases. CONCLUSION: 10-15 years after the Chornobyl accident, thyroid cancer risk was significantly increased among individuals exposed to fallout as children or adolescents, but the risk appeared to be lower than in other Chornobyl studies and studies of childhood external irradiation

The Flux-Line Lattice in Superconductors

Magnetic flux can penetrate a type-II superconductor in form of Abrikosov vortices. These tend to arrange in a triangular flux-line lattice (FLL) which is more or less perturbed by material inhomogeneities that pin the flux lines, and in high-$T_c$ supercon- ductors (HTSC's) also by thermal fluctuations. Many properties of the FLL are well described by the phenomenological Ginzburg-Landau theory or by the electromagnetic London theory, which treats the vortex core as a singularity. In Nb alloys and HTSC's the FLL is very soft mainly because of the large magnetic penetration depth: The shear modulus of the FLL is thus small and the tilt modulus is dispersive and becomes very small for short distortion wavelength. This softness of the FLL is enhanced further by the pronounced anisotropy and layered structure of HTSC's, which strongly increases the penetration depth for currents along the c-axis of these uniaxial crystals and may even cause a decoupling of two-dimensional vortex lattices in the Cu-O layers. Thermal fluctuations and softening may melt the FLL and cause thermally activated depinning of the flux lines or of the 2D pancake vortices in the layers. Various phase transitions are predicted for the FLL in layered HTSC's. The linear and nonlinear magnetic response of HTSC's gives rise to interesting effects which strongly depend on the geometry of the experiment.Comment: Review paper for Rep.Prog.Phys., 124 narrow pages. The 30 figures do not exist as postscript file

Teaching Quality Assurances in Higher Education Institution: Competence-Based Approach

Use of research methods (analytic and synthetic, modeling, studying of psychology and pedagogical literature and products of activity) allowed researchers of the study to prove relevance of a problem of providing quality assurance of teaching in higher education institution on the basis of competence-based approach to be defined in concept of teaching quality assurance system to develop mechanisms, means, conditions, model of system realization. As the bases for development of teaching quality assurance system realization model the grounds of competence-based approach, the increasing requirements of the state, society, family and personality to education quality, their dissatisfaction with speed and adequacy of the happening changes ac

Secondary neutrons generated by medical linear electron accelerator

Section V. Equipment, Methods and Automation of Nuclear Experiments, Interaction of Nuclear Radiation with the Matter and Applications of Methods of Nuclear Physic

Application of Monte Carlo method to the dosimetry X-ray examinations

Section V. Equipment, Methods and Automation of Nuclear Experiments, Interaction of Nuclear Radiation with the Matter and Applications of Methods of Nuclear Physic

Reconstruction of thyroid doses for the population of Belarus following the Chernobyl accident

As a sequela to the large release of {sup 131}I from the accident at the Chernobyl Nuclear Power Plant, an expected late effect is thyroid cancer, especially in children. In anticipation of this problem, hundreds of thousands of measurements of thyroid glands were made with survey meters. Much attention was also focused on measuring the deposition density of {sup 137}Cs. The expectation was that the latter measurement could be a good surrogate for the deposition density of {sup 131}I, so that ecological models could be used to reconstruct thyroid doses in locations where no direct measurements of thyroid activity were made. However, this assumption has been seriously questioned, and there is interest in a more suitable surrogate that can still be measured even nine years or more after the accident. The purpose of this paper is to discuss the reconstruction of thyroid doses for a case-control study of childhood-thyroid cancer that has just been concluded, to discuss the reconstruction of thyroid doses for a current cohort study of childhood-thyroid cancer, and to discuss the use of {sup 129}I as a surrogate for the deposition density of {sup 131}I

The influence of the vagus nerve and indole derivative SS-68 on excitation processes in the SA node

Introduction: Atrial fibrillation (AF) is the most common form of cardiac arrhythmias. Studying the pathogenesis of this pathological process will make it possible to look for new methods of treating AF and to predict its occurrence in a more targeted way. The aim of the study was to identify the components of the takeover process of central rhythmogenesis by the SA node in the conditions of atrial fibrillation when stimulating the vagus nerve and using substance SS-68. Materials and Methods: The experiments were conducted on 30 frogs and 90 cats. In frogs, the activity of the regions of the medulla oblongata synchronous with the heart rhythm was determined in a high-frequency electromagnetic field. In cats, proximal and distal foci of luminescence in the vagus nerve (VN) and pools of pacemaker cells (PCs) in the sinoatrial node were visualized under topical and general anesthesia, using a KELSY scanner with a microscope video capture unit while stimulating VN and using SS-68. Results and Discussion: The stimulation of VN with volleys of electrical impulses and the introduction of SS-68 increase the foci of luminescence in the nerve and unite the PC pools. This way, under general anesthesia in comparison with topical anesthesia, the area of the proximal focus of VN luminescence decreased by 83.8%, and the distal focus – by 44.9%. Against the background of general anesthesia, the area of the proximal focus of luminescence when stimulating VN with volleys of electrical impulses was by 76.0% larger than before stimulation, and the distal focus – by 72.5%. After the administration of SS-68, there was an increase in the foci of luminescence: under general anesthesia, when compared with topical anesthesia, the area of the proximal foci of luminescence decreased by 86.8%, and the distal one – by 67.1%. Under general anesthesia, the area of the proximal focus of luminescence under conditions of stimulating VN with volleys of electrical impulses was by 82.2% larger than before stimulation and the distal one – by 78.2%. When signals from the brain arrive simultaneously through VN at the PC pools, they are absorbed by the PC pools; the focus of early depolarization becomes wide, which prevents the development of AF. The increased synchronizing influence of VN may be one of the methods for treating autonomic AF, and if its influence decreases, it can be a prognostic factor for the occurrence of recurrent AF. Conclusion: The tonic effect of VN on the heart rhythm through electrical stimulation of the former and the use of SS-68 is manifested in a decreased heart rate: the difference between the initial heart rhythm and the minimal synchronization range boundary. A decrease in the heart rate under the influence of VN prevents paroxysms of AF, but does not completely eliminate the influence of ectopic foci on it