Crustal and Upper Mantle Velocity Model along the DOBRE-4 Profile from North Dobruja to the Central Region of the Ukrainian Shield : 1. Seismic Data

For studying the structure of the lithosphere in southern Ukraine, wide-angle seismic studies that recorded the reflected and refracted waves were carried out under the DOBRE-4 project. The field works were conducted in October 2009. Thirteen chemical shot points spaced 35-50 km apart from each other were implemented with a charge weight varying from 600 to 1000 kg. Overall 230 recording stations with an interval of 2.5 km between them were used. The high quality of the obtained data allowed us to model the velocity section along the profile for P-and S-waves. Seismic modeling was carried out by two methods. Initially, trial-and-error ray tracing using the arrival times of the main reflected and refracted P-and S-phases was conducted. Next, the amplitudes of the recorded phases were analyzed by the finite-difference full waveform method. The resulting velocity model demonstrates a fairly homogeneous structure from the middle to lower crust both in the vertical and horizontal directions. A drastically different situation is observed in the upper crust, where the Vp velocities decrease upwards along the section from 6.35 km/s at a depth of 15-20 km to 5.9-5.8 km/s on the surface of the crystalline basement; in the Neoproterozoic and Paleozoic deposits, it diminishes from 5.15 to 3.80 km/s, and in the Mesozoic layers, it decreases from 2.70 to 2.30 km/s. The sub-crustal Vp gradually increases downwards from 6.50 to 6.7-6.8 km/s at the crustal base, which complicates the problem of separating the middle and lower crust. The Vp velocities above 6.80 km/s have not been revealed even in the lowermost part of the crust, in contrast to the similar profiles in the East European Platform. The Moho is clearly delineated by the velocity contrast of 1.3-1.7 km/s. The alternating pattern of the changes in the Moho depths corresponding to Moho undulations with a wavelength of about 150 km and the amplitude reaching 8 to 17 km is a peculiarity of the velocity model.Peer reviewe

Dynamics of psychophysiological functions and indicators of physical and technical readiness in young football players aged 12-13 and 15-16 years during a 3-month training process

Dynamics of psychophysiological functions and indicators of physical and technical readiness in young football players aged 12-13 and 15-16 years during a 3-month training process / Zhanneta Kozina, Marian Cretu, Danil Safronov, Ivan Gryn, Yurii Shkrebtii, Nataliya Bugayets, Tatiana Shepelenko, Andrii Tanko // Physiotherapy Quarterly. – 2019. – № 27 (3). – Р. 20-27. – DOI: https://doi.org/10.5114/pq.2019.86464Метою дослідження було дати порівняльну характеристику динаміки психофізіологічних функцій та показників фізичної та технічної підготовленості юних футболістів 12–13 та 15–16 років за період 3 місяців тренувань.The purpose of the research was to provide a comparative characteristic of the dynamics of psychophysiological functions and indicators of physical and technical readiness of young footballers aged 12–13 and 15–16 years during 3 months of training.Цель исследования – дать сравнительную характеристику динамики психофизиологических функций и показателей физической и технической подготовленности юных футболистов 12–13 и 15–16 лет за 3 месяца тренировок

Mesoporous silicon carbide: Via nanocasting of Ludox® xerogel

Porous SiC with uniformly sized 12 nm and 22 nm spherical mesopores was synthesized from nanocomposites of polycarbosilane (PCS) preceramic polymer and xerogels of Ludox® SiO2 nanoparticles as templates. The influence of PCS type (Mw 800 and 2000 Da), PCS:SiO2 ratio, pyrolysis temperature 1200-1400 °C, and addition of Ni complex to the preceramic composite was studied with respect to the SiC porous morphology, crystalline structure and chemical properties. We found that the pore walls of Ni-free por-SiC are composed of relatively large (20 nm) crystallites embedded inside a poorly crystalline SiC/SiC1+x phase. Increasing the pyrolysis temperature resulted in an increase of the large crystallites fraction, as well as of the stability with regard to air oxidation; however, some degradation of the porous morphology was noted too. The presence of Ni (1.5% wt relatively to PCS) noticeably improved the crystallinity of por-SiC prepared at 1200-1300 °C, with no degradation of the porous morphology occurring. On the other hand, higher Ni loadings and temperatures led to the transformation of the porous morphology into aggregates of irregularly packed large crystallites.SCOPUS: ar.jinfo:eu-repo/semantics/publishe