Optical models of the molecular atmosphere

The use of optical and laser methods for performing atmospheric investigations has stimulated the development of the optical models of the atmosphere. The principles of constructing the optical models of molecular atmosphere for radiation with different spectral composition (wideband, narrowband, and monochromatic) are considered in the case of linear and nonlinear absorptions. The example of the development of a system which provides for the modeling of the processes of optical-wave energy transfer in the atmosphere is presented. Its physical foundations, structure, programming software, and functioning were considered

Surgical treatment of the ischemic heart disease with lowered contractility of left ventricle and mitral valve insufficiency

Objective. To determine the impact of the mitral valve insufficiency in patients, suffering ischemic heart disease with lowered contractility of left ventricle and methods of its treatment. Materials and methods. During 01.01.2015-31.12.2018 yrs period in the Amosov National Institute of Cardiovascular Surgery there were conducted 2267 consecutive operations of coronary shunting, of them 190 (8.4%) - in patients, suffering the ischemic heart disease with lowered contractility of left ventricle. Reduction of the output fraction of left ventricle down to 35% and lower have served as criterion of inclusion of the patients into the Group. There were 170 (89.5%) men and 20 (10.5%) women. The patients’ age have constituted 29 - 83 yrs old, (61.1 ± 8.9) yrs old at average. Results. In 47.9% of the patients the lowering of the left ventricle contractility after myocardial infarction was followed by occurrence of regurgitation on a mitral valve. At the same time it was noted, that the regurgitation value have had correlated with degree of the left ventricle contractility lowered: in reduction of values of the left ventricle output fracture down to 25% and lower a moderate regurgitation on a mitral valve was registered up to 2 times, a significant one - in 2.5 times, and the pronounced one - in 1.5 times more frequently, than in values of the left ventricle output fracture, exceeding 25%. Occurrence of a mitral insufficiency in 18.7% patients was caused by direct damage of valvular apparatus, while in 81.3% patients the consequences of the heart cavities were present in disorder of contractile function of myocardium. Presence of postinfarction mitral insufficiency enhances the risk of an acute cardiac insufficiency in 1.7 times and necessitates intraoperative correction in values of the regurgitation fraction over 30%. Conclusion. The own data obtained witness, that noncorrected mitral insufficiency in the ischemic heart disease worsens significantly the postoperative period course after performance of coronary shunting, enhancing rate of an acute cardiac, respiratory and renal insufficiency. Thus, taking into account a negative impact of concomitant mitral valve insufficiency on efficacy of surgical interventions in the lowered contractility of left ventricle the need emerges to perform complex reconstructive intervention in patients, suffering ischemic heart disease with lowered contractility of left ventricle

Beam coupling in hybrid photorefractive inorganic-cholesteric liquid crystal cells: impact of optical rotation

We develop a theoretical model to describe two-beam energy exchange in a hybrid photorefractive inorganic-cholesteric cell. A cholesteric layer is placed between two inorganic substrates. One of the substrates is photorefractive (Ce:SBN). Weak and strong light beams are incident on the hybrid cell. The interfering light beams induce a periodic space-charge field in the photorefractive window. This penetrates into the cholesteric liquid crystal (LC), inducing a diffraction grating written on the LC director. In the theory, the flexoelectric mechanism for electric field-director coupling is more important than the LC static dielectric anisotropy coupling. The LC optics is described in the Bragg regime. Each beam induces two circular polarized waves propagating in the cholesteric cell with different velocities. The model thus includes optical rotation in the cholesteric LC. The incident light beam wavelength can fall above, below, or inside the cholesteric gap. The theory calculates the energy gain of the weak beam, as a result of its interaction with the pump beam within the diffraction grating. Theoretical results for exponential gain coefficients are compared with experimental results for hybrid cells filled with cholesteric mixture BL038/CB15 at different concentrations of chiral agent CB15. Reconciliation between theory and experiment requires the inclusion of a phenomenological multiplier in the magnitude of the director grating. This multiplier is cubic in the space-charge field, and we provide a justification of the q-dependence of the multiplier. Within this paradigm, we are able to fit theory to experimental data for cholesteric mixtures with different spectral position of cholesteric gap relative to the wavelength of incident beams, subject to the use of some fitting parameters

Geophysical studies with laser-beam detectors of gravitational waves

The existing high technology laser-beam detectors of gravitational waves may find very useful applications in an unexpected area - geophysics. To make possible the detection of weak gravitational waves in the region of high frequencies of astrophysical interest, ~ 30 - 10^3 Hz, control systems of laser interferometers must permanently monitor, record and compensate much larger external interventions that take place in the region of low frequencies of geophysical interest, ~ 10^{-5} - 3 X 10^{-3} Hz. Such phenomena as tidal perturbations of land and gravity, normal mode oscillations of Earth, oscillations of the inner core of Earth, etc. will inevitably affect the performance of the interferometers and, therefore, the information about them will be stored in the data of control systems. We specifically identify the low-frequency information contained in distances between the interferometer mirrors (deformation of Earth) and angles between the mirrors' suspensions (deviations of local gravity vectors and plumb lines). We show that the access to the angular information may require some modest amendments to the optical scheme of the interferometers, and we suggest the ways of doing that. The detailed evaluation of environmental and instrumental noises indicates that they will not prevent, even if only marginally, the detection of interesting geophysical phenomena. Gravitational-wave instruments seem to be capable of reaching, as a by-product of their continuous operation, very ambitious geophysical goals, such as observation of the Earth's inner core oscillations.Comment: 29 pages including 8 figures, modifications and clarifications in response to referees' comments, to be published in Class. Quant. Gra

Home Experiment with Physics in High School

Запровадження компетентнісного підходу в системі освіти України має певні особливості стосовно кожного навчального предмету. У загальній фізичній освіті компетентнісний підхід є засобом посилення дієвості предметних знань, умінь та навичок учнів, а отже, реалізація його має здійснюватися шляхом посилення практичної, прикладної спрямованості навчального процесу. У цьому контексті важливе місце в системі навчання фізики має належати навчальному фізичному експерименту, частиною якого є домашні досліди і спостереження. Виконання домашніх експериментальних завдань сприяє засвоєнню програмного теоретичного матеріалу, формуванню в школярів експериментальних умінь та навичок, а також конструкторських здібностей. Враховуючи широкі педагогічні можливості домашнього експерименту, його слід розглядати як невід’ємний елемент навчального процесу з фізики в старшій школі, що потребує ретельного планування. Педагогічна практика свідчить на користь системного використання домашніх лабораторних робіт в старшій школі. Це означає, що цей вид навчальної роботи має бути чітко спланованим і охоплювати усі теми шкільного курсу фізики. У профільних класах та класах з поглибленим вивченням фізики можливий практикум з домашнього фізичного експерименту. У статті наведено приклади домашніх лабораторних робіт, які можуть бути використані в навчальному процесі з фізики в старшій школі.The introduction of the competence approach in the education system of Ukraine has certain features for each subject. In a General physical education competence approach is a means to enhance the usefulness of subject knowledge, abilities and skills of students and, therefore, its implementation should be carried out by enhancing the practical, applied orientation of the learning process. In this context, an important place in the system of physics teaching must be an educational physical experiment, part of which is home tests and monitoring. The experimental homework tasks contributes to the assimilation of the program of theoretical material, the formation of students ' experimental skills and design abilities. Given the broad educational opportunities of the home experiment, it should be viewed as an integral part of the educational process in physics in high school, which requires careful planning. Teaching practice evidence in favor of the systematic use of domestic laboratory work in high school. This means that this type of study should be clearly planned and should include all subjects of the school course of physics. In specialized classes, and classes with advanced study of physics possible, a workshop on homemade physical experiment. The article provides examples of domestic laboratory work, which can be used in the educational process in physics in high school

Optimal design of turbines taking into consideration the mode of operation

The technique of turbines parameters optimization taking into consideration a variable mode of their operation has been developed. Block-hierarchical representation of design process is used. The hierarchy of local optimization problems is organized by a functional sign and realized in a common information space. The structure of optimization technique is shown, and also the analysis of the data streams uniting these problems in unified process of optimal design is resulted. By means of the developed technique optimal design of the 4-stage turbine expander with rated power 4 MW has been performed. Results of the design are presented and analyzed

Very high frequency gravitational wave background in the universe

Astrophysical sources of high frequency gravitational radiation are considered in association with a new interest to very sensitive HFGW receivers required for the laboratory GW Hertz experiment. A special attention is paid to the phenomenon of primordial black holes evaporation. They act like black body to all kinds of radiation, including gravitons, and, therefore, emit an equilibrium spectrum of gravitons during its evaporation. Limit on the density of high frequency gravitons in the Universe is obtained, and possibilities of their detection are briefly discussed.Comment: 14 page