Mixing of scalar and tensor metric perturbations

Metric perturbations in General Relativity are usually separated into three distinct classes: scalar, vector, and tensor. In many cases these modes are separable, i.e. they satisfy independent equations of motion for each mode. However, in the present paper we argue that in many cases tensor and scalar modes are not separable, no matter what gauge conditions are chosen. The propagation of any of these mode depends on the other. A realistic example providing such mixing is presented.Comment: 10 page

On graviton propagation in curved space-time background

Equation describing propagation of gravitational waves (GW) over arbitrary curved space-time background is analyzed. A new term, which is absent in the conventional homogeneous and isotropic Friedmann cosmology, is found. Some examples of realistic metric, where this new term manifests itself, are presented. Possible implications to very low frequency GW are briefly discussed.Comment: 9 page

The effect of dry friction forces on the process of dielectric wafer grinding

We have investigated possible motions of the holder on top of the polishing pad during the process of dielectric plate grinding taking into account the forces of dry friction about its axis. A mathematical model of the mechanical device has been elaborated to describe the process of dielectric wafer grinding. The model is in the form of a non-autonomous nonlinear system with a variable structure. The structure of the phase space of the dynamical system was investigated, the qualitative studies of the possible motion modes were carried out. The values of the geometrical and dynamic parameters that qualitatively and quantitatively influence the modes of the holder motion were obtained. It was found that the inclusion of dry friction forces on the axis of the free holder result in a periodic motion of the mechanism with long stops. We present the calculations of the parameters for the type 3PD-320 machine

Impact of self-regulation methods on the psycho-emotional state of future teachers

The authors remark the necessity to develop the psycho-emotional self-assessment and self-regulation capability of future teachers during the period of vocational training at the university. The training program on the development of students' psycho-emotional self-regulation is presented. The possibility of training practice on behavior and activity self-regulation development as one of the phenomena of a person’s mental life is investigated via methods of questioning, operational control of neuropsychic activity (electrocutaneous resistance), and the Luscher tes

Quantitative determination of methanol and propanol-2 in tinctures and extracts using head-space gas chromatography in comparison with method of vaporization of liquid in GC inlet

The aim of this work was to compare sensitivity of methods for determination of methanol and propanol-2 contents in tinctures and extracts. Materials and methods. Two methods suggested in the State Pharmacopoeia of Ukraine for determination of the above mentioned compounds in liquid medicines were used, specifically: head-space gas-chromatography (method A) and classic gas chromatography (method B) with common injection technique. The research was conducted on one of the most popular medicinal products based on ethanol extracts of herbal drugs: echinacea (Tinctura Echinaceae), hawthorn (Tinctura Crataegi), and motherwort tinctures (Tinctura Leonuri). All medicines used were manufactured at pharmaceutical factory “VIOLA” (Zaporizhzhia, Ukraine). Substance analysis was held on gas chromatograph Agilent 7890B (USA) coupled to head – space sampler DANI HSS 86.50 Plus (Italy). Compounds were separated on J&W Agilent DB-624 (USA) column. In the study quantitative contents of methanol and propanol-2 were evaluated in tinctures and extracts using methods of head – space gas chromatography and liquid evaporation in the GC inlet (common injection technique), sensitivities of both methods were compared due to signal-to-noise levels. Statistical parameters of the obtained results were assessed (average, error, variance). Results. The results demonstrated that methanol and propanol-2 contents in tinctures did not exceed the limit value, which is set to 0.05 %. However, it was showed that classic gas chromatography is not able to give information about amounts of propanol-2 in substances, while head-space chromatography has determined concentration of this compound in all examined tinctures. It was determined that head-space GC has higher signal-to-noise levels. Conclusions. Considering all shown results and their discussion, it was concluded that method of head – space GC is more sensitive for determination of volatile impurities in liquid medicinal products than classic gas chromatography with common injection technique

The symbolism of colour in the interpretation of a drawing in Gestalt

The article investigates the peculiarities of colour symbolism and semantics that might be applied in the interpretation of a projective drawing in Gestalt. As a result, a child’s drawing is a kind of figurative art; this is something that has to evoke not just the viewer’s thoughts and feelings about the depicted figurative material. In conclusion, we can supplement a diagnostic component part with a new approach of psychodiagnosis problem-solving of individual and typological features of personality peculiarities in the modern pedagogical educational proces

FEATURES OF HEART RATE REGULATION IN ADOLESCENTS WITH ESSENTIAL HYPERTENSION

Cardiointervalography is an important method of analyzing the regulation of heart rate variability, which allows evaluating the balance of the entire spectrum of humoral-metabolic and vegetative effects, both in condition of physiological rest and in various functional tests. It is noted that in hypertensive patients, in most cases, there is a chronic predominance of ergotrophic metabolic reactions that reflect the system tension in the regulatory mechanisms. The aim of our study was to conduct a comparative analysis of the features of the mechanisms of heart rate regulation in adolescents with confirmed essential hypertension and their healthy age mates. Material and methods. The study involved 50 adolescents (12–16 years of age) – 26 boys and 24 girls with labile essential hypertension (EHT) and stage 1 HT on the background of the standard medical correction of blood pressure (enalapril 0,58 mg/kg per day). Each participant of the study and control group underwent recording of at least 512 cardio cycles in the state of physiological rest in a sitting position, as well as registration of blood pressure. Results and discussion. We have found that for adolescents with EHT a significantly lower (by 15 %) average duration of the heart cycle is typical in combination with a decrease in the variation range, which indicates some rigidity of the heart rate regulatory mechanisms. The relative decrease in the proportion of high-frequency spectrum components in comparison with the low-frequency and very low-frequency ranges in adolescents with hypertension also indicated a tendency to predominance of sympathicotonic effects with the predominant involvement of the structures of the diencephalic region and the brain stem. At the same time blood pressure inversely correlated with the index of the variation range of cardiointervals, reflecting the lower adaptive potential of the heart rate regulation mechanisms. Conclusion. We have found regular changes in the regulation of heart rate in adolescents with hypertension, that can be taken as markers of its progressive development and used by clinicians to develop more personalized approaches to medication treatment

Some questions about Teae folia (Thea sinensis L. seu Camellia sinensis L. Kuntze) as a medicinal raw material

One of the most popular plant and beverage is a Thea sinensis or Camellia sinensis (Theaceae) also known as Theae Folia or Green Tea. There are some reasons for it, such that the sensory properties, prices are relatively cheap, stimulant effects, and their potential health benefits. Motherland of this plant is considered the China. This is where people have paid attention to the ability of a decoction of the leaves have a tonic effect on the human body and the first to grow this plant. Tea folia as a medicine are made from unfermented tea leaves and young shoots. This process is fast in special drying machines. Objective: European Pharmacopoeia have monograph Green Tea and the herb that we know as a food drink have as medicine herb now. The objective of research of herbal medicine is the quality and safety of natural products. Materials and Methods: Macroscopical and microscopical features of the leaf and shoots have been analysis using an optical microscope. Phytochemical and physico-chemical analysis were evaluated. The observation of the spectrum profiles is done by interpreting the typical peak that appears. Results: Theae Folia have actinocytic stomata, unicellular trichomes, heterogenous mesophyll which is characterized by the presence of calcium oxalate crystals and sclereid cells. Phytochemical analysis indicated resources the presence of purine alkaloids caffeine and theabromine and many other drugs. The content of caffeine from Teae Folia ethanolic and water extract is differ to time. Conclusion: Pharmacognostic and phytochemicals features established in this study may be used as part of the pharmacopoeial standard, which can play an important role in its standardization