Luminescence spectra of germanosilicate optical fibres I - radioluminescence and cathodoluminescence

Data are reported on the luminescence spectra generated by X-ray and electron irradiation of optical fibres, fibre preforms and silica. The impurities and imperfections in the fibre core have a higher luminescence efficiency than those in the substrate material. The core luminescence provides a major fraction of the total light emission, despite the fact that the core is a small fraction of the total fibre volume. A wide variety of overlapping emission bands are reported. The spectra are strongly temperature dependent but the component emission bands can generally be linked to either Ge impurities, giving the 400 nm band, exciton emission near 460 nm or other blue/UV bands linked to E'-type defects. Overall, the study of the fibre luminescence provides a sensitive technique for analysis d changes and repeatability of fibre fabrication

Dynamics of stress-index and spectral indicators of cardiointervalogram of elite skiers-racers in the preparatory, competition and transition periods depending on the volume and intensity of training loads

Acutality: Heart rate variability, allows you to assess the state of the autonomic nervous system, which is useful for studying the condition of athletes, including endurance athletes, for example, ski racers. The stress index indicator is often used to assess the impact of stress on a person. It is shown that the stress index is closely correlated with the intensity of metabolism and with the indicators of energy consumption of the body.Objective. To provide information on the values of the stress index for athletes depending on a number of factors, including their sports specialization, and for ski racers on the volume and intensity of the training load during the preparatory, competitive, transitional periods of the ski season.Materials and methods. The literature analysis in the Pubmed database for the last 10 years in English and Russian languages has been carried out.Conclusion. A review of the literature on the magnitude of the stress index showed that athletes who train for endurance, this indicator is low, especially among ski racers, if it is compared with the magnitude of the index in representatives of other sports, as well as with healthy people who do not play sports. There is no information about the value of the stress index in athletes in foreign literature, but there is such information in the domestic literature, which allowed us to present this review, which also includes the results of our research

Dynamics of the RRNN interval of the cardiointervalogram depending on the specialization of the training process, stage of the annual preparation cycle and other factors (review)

In order to study the mechanisms of adaptation to loads that require high endurance, the article analyzes and systematizes the literature and the results of our own studies of the duration of the RRNN interval of the cardiointervalogram/heart rate (HR) in the prone position among athletes, in particular, among cross-country skiers. It has been established that the value of RRNN depends on sports specialization (maximum for athletes training for endurance), on the length of training and the level of sportsmanship (for cross-country skiers, with an increase in the level of skill, the value of RRNN increases, and heart rate decreases), on the periods of the annual cycle. So, the athlete K.D. it is maximum in the preparatory period (1497 ms/40 beats/min), but lower in the competition (1477 ms/40.6 beats/min) and in the transition (1467 ms/ 40.8 beats/min) periods. The value of RRNN also depends on the stage of the training camp, or TCB. So, the athlete K.D. from the beginning of the TS to its end, it gradually increases - from 1423 ms to 1572 ms, and the heart rate decreases accordingly from 42.1 to 38.1 beats/min. It was shown that the type of vegetative regulation of heart activity in elite skiers does not change during the annual cycle (all members of the Tatarstan team had type IV regulation according to the classification of N.I. Shlyk, i.e. vagotonia). This confirms the notion that endurance training increases the influence of the parasympathetic system on the activity of the heart. The results of the study of the elite skier-racer K.D. (the first author of the article), fixing the volume and intensity of the training load in all three periods of the annual cycle, as well as the results of a study of the Tatarstan national team (without fixing the loads), revealed that, in general, throughout the season, including in the preparatory period, the median RRNN correlates with the volume (Vkm; Vmin) training loads (the higher they are, the greater the median RRNN). However, the competitive period is characterized by an inverse dependence of the median RRNN on the volume (Vmin) of the load, which is regarded as a reflection of the formation of an anxiety state in this period, although the formation of an anxiety state in the team of Tatarstan (n = 8) was not detected in the competitive period (they have a median of RRNN in the preparatory period was 1430 ms/42 beats/min), and in the competition period – 1490 ms/40.2 beats/min). The authors conclude that even a palpatory calculation of the heart rate of a cross-country skier in conditions of clinostasis (rest) can serve as a guideline in managing the training process, since an increase in heart rate with exercise therapy indicates a decrease in physical performance, and a progressive decrease in heart rate (up to 38 beats/min) – on its increase, as well as on the formation of the synthesis of non-neuronal acetylcholine (ACh). It is assumed that excessive production of non-neuronal ACh, which can lead to weakness of the sinus node, is prevented by a significant increase in ANS SO activity in elite skiers

The effect of irradiation on the magnetic properties of rock and synthetic samples: Implications to irradiation of extraterrestrial materials in space

© 2015, Pleiades Publishing, Ltd. We report here the results of laboratory analog experiments to consider the potential effects of solar energetic particles (SEP or solar-flare-associated particles) and galactic cosmic rays (GCR) on the magnetic properties of extraterrestrial materials. We carried out proton bombardment experiments (with irradiation energies E1=400, E2 =850 keV and three irradiation fluences in 1014–1016p/cm2 range) and lead-ion bombardment experiments (E =1 GeV) on (previously demagnetized by 120 mT alternating magnetic field) rock and synthetic samples with the following magnetic carriers: metallic iron and nickel iron, Ti-rich and Ti-free magnetite, pyrrhotite. Irradiation experiments resulted in either further demagnetization or magnetization of irradiated samples depending on the type of magnetic mineralogy and type of ionizing radiation involved. Apart for the formation of radiation-induced remanent magnetization (RIRM), we observed major changes in bulk magnetic properties, i.e., a moderate to dramatic decrease (up to 93%) in the coercivity of remanence Bcr for all iron-bearing phases (iron-in-epoxy and Bensour meteorite samples). Contrary to iron-bearing samples, several magnetite-bearing samples experienced a radiation-induced magnetic hardening (increase in Bcr). Magnetic hardening was also observed for Ar2+ ion-irradiated nickel iron-bearing HED meteorites, measured for comparison with the previously stated results. Therefore, the combined effect of SEP with GCR may magnetically soften iron-bearing materials and harden magnetite-bearing materials. In order to answer the question wether RIRM may account for natural remanent magnetization of meteorites and lunar samples, physical mechanism of RIRM formation and potential dependence of RIRM intensity on the background magnetic field present during irradiation event should be investigated

Estimated Inpatient Hospital Stay in Individual Wards: Guidelines on Radiation Safety after Radioiodine Therapy

Radionuclide therapy safety requirements are regulated by the Russian Radiation Safety Standards (RRSS), which state the maximum allowed radionuclide activity in the body and the equivalent dose rate (EDR) of gamma radiation. Therefore, it is necessary to estimate the time of an inpatient hospital stay in specially designed radionuclide therapy wards. The article presents the findings of individual 131I biokinetics studies in 64 patients admitted to radioiodine therapy of thyrotoxicosis and differentiated thyroid cancer. We developed a method to calculate the time interval to reach the EDR of 20μSv/h and the recommended EDR of 3 and 0.3μSv/h for adults and children, respectively. It is based on the measurement of the 131I excretion constant. Keywords: Radioiodine therapy, Radiation safety, Guidelin