Conceptually new methods of hydrate formation are proposed. The first one is based on the shock wave impact on a water-bubble medium. It is shown that the hydrate formation rate in this process is ...typically very high. A gas hydrate of carbon dioxide was produced. The process was experimentally studied using various initial conditions, as well as different external action magnitudes. The obtained experimental data are in good agreement with the proposed model. Other methods are based on the process of boiling liquefied gas in an enclosed volume of water (explosive boiling of a hydrating agent and the organization of cyclic boiling-condensation process). The key features of the methods are the high hydrate formation rate combined with a comparatively low power consumption leading to a great expected efficiency of the technologies based on them. The set of experiments was carried out. Gas hydrates of refrigerant R134a, carbon dioxide and propane were produced. The investigation of decomposition of a generated gas hydrate sample was made. The criteria of intensification of the hydrate formation process are formulated.
We report on the earliest detection of the optical transient MASTER OT J123248.62-012924.5 coincident within the error box with the optical and X-ray transient AT2021lfa/ZTF21aayokph. In our images ...the brightness of the object rises monotonically with
confidence. We interpret this transient as a gamma-ray burst (GRB) characterized by smooth optical self-similar (SOSS) emission, while the nondetection of gamma-ray emission at space observatories is interpreted in terms of the hypothesis of a ‘‘failed’’ GRB. Thus, this is the first detection of a nonmonotonic orphan burst.
This paper considers latest highlights in simultaneous and follow-up optical observations of high energy astrophysical phenomena by MASTER Global Robotic Net. Such extreme Universe sources includes ...gamma-ray bursts, gravitational wave events, detected by LIGO/Virgo, fast radio bursts, high energy neutrino sources and others. Some of the neutrinos detected by ground-based facilities owe their births to supermassive black holes – blazars, which are in a special anxious state with high statistical reliability. We discovered the effect of a rapid decrease in the brightness of the blazar PKS 0735+17 at the time of the multiple detection of the high-energy neutrino event IceCube-211208A. This decrease in brightness within several hours was detected with a high confidence (SNR 10) in comparison with a multi-day brightening state of the blazar, which was accompanied not only by a maximum increase in the average brightness, but also by an increase in the amplitude of its brightness fluctuations. Additionally, we analyzed all cases of successful observation of blazars around neutrino events and obtained statistically reliable indications of the relationship between neutrino events and optical activity of blazars in the doubled error box at the 4.2
level.
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We present the results of early observations for 130 error-boxes of gamma-ray bursts performed with the Mobile Astronomical System of TElescope-Robots (MASTER) global network of robotic telescopes ...from Moscow State University in fully automatic mode (2011–2017). Among them, GRB 130907A, GRB 120811C, GRB 110801A, GRB 120404A, GRB 140129B, GRB140311B, and GRB 160227A are considered in details. Among these 130 gamma-ray bursts, in the first 60 s after the trigger with the Swift, Fermi, INTEGRAL, MAXI, Lomonosov, and Konus-Wind orbital observatories, the MASTER was pointed on 51 gamma-ray bursts, being the leader in terms of the first pointing. Full observation automation and MASTER own real-time image processing software allowed us to obtain unique data on early optical emission that accompanied 44 gamma-ray bursts (GRB 110801A, GRB120106A, GRB 120404A, GRB 120811C, GRB 120907A, GRB 121011A, GRB 130122A, GRB 130907A, GRB 131030A, GRB 131125A, GRB 140103A, GRB 140108A, GRB 140129B, GRB 140206A, GRB 140304A, GRB 140311B, GRB 140512A, GRB 140629A, GRB 140801A, GRB140907A, GRB 140930B, GRB141028A, GRB 141225A, GRB 150210A, GRB 150211A, GRB 150301B, GRB 150323C, GRB 150404A/Fermi trigger 449861706, GRB 150403A, GRB 150413A, GRB 150518A, GRB 150627A, GRB 151021A, GRB 151215A, GRB 160104A, GRB 160117B, GRB 160131A, GRB 160227A, GRB 160425A, GRB 160611A, GRB 160625B, GRB 160804A, GRB 160910A, GRB 161017A, GRB 161117A, GRB 161119A). We obtain light curves for 13 gamma-ray bursts among the above listed ones and compare the data in the optical (MASTER), X-ray (Swift-XRT), and hard X-ray (Swift-BAT) ranges.
The results of white-light photometry for a uniquely long series of data (13.5 hours of observations, 1124 measurements) for the Near-Earth Asteroid (NEA) 2015 TB145 are presented. These data were ...obtained with the MASTER-Amur and MASTER-Tavrida wide-field robotic telescopes of the Mobile Astronomical System of Telescope-Robots (MASTER) global network of Lomonosov Moscow State University, located in the Crimea and in Blagoveshchensk. The object moved by more than 120° during the observations. The asteroid passed the point of closest approach to the Earth, i.e., observations were carried during both the asteroid's approach and recession. Thus, due to the geometry of the passage, this series of observations contains information about the asteroid viewed at different angles, and is very suitable for precisely determining the shape of the object. Mathematical modeling of the light curve and astrometric positions (with the Asteroids3D code) was carried out, and the probable shape of the asteroid (conical) and the rotation period of 5.9 hours were obtained, as well as the orientation of the rotation axis in ecliptic coordinates: longitude λ = 53°, latitude β = −20°. The derived period coincides with twice the period of 2.9 hours obtained by other observers published earlier, within the uncertainties.
2-(p-Tolylsulfanyl)-2-trifluoromethyl-3,6-dihydro-2Н-thiopyran 1-oxides undergo a vinylogous Pummerer reaction upon interaction with trifluoroacetic anhydride, forming ...2-(p-tolylsulfanyl)-4-tri-fluoroacetoxy-2-trifluoromethyl-3,4-dihydro-2Н-thiopyrans. The hydrolysis, acetylation, and free radical desulfanylation of these compounds with a subsequent oxidation of the sulfur atom leads to 4-acetoxy-2-trifluoromethyl-3,4-dihydro-2Н-thiopyran 1-oxides. The Pummerer addition reaction of the latter with acetic anhydride and boron trifluoride etherate results in a ring contraction and formation of 3-acet-oxy-2-diacetoxymethyl-5-(trifluoromethyl)thiolanes, which could be converted with sodium boro-hydride to 3-hydroxy-2-hydroxymethyl-5-(trifluoromethyl)thiolanes having antiviral activity.
2070 unique, homogeneous photometric and polarization observations of the microquasar in a binary system with a black hole V404 Cyg/GS2023+338 obtained in 2015 with the MASTER global network of ...robotic telescopes (16 robotic telescopes located at eight points on the Earth in Russia, Spain, South Africa, and Argentina) are presented. MASTER was the first telescope network to obtain optical observations of the microquasar after its gamma-ray outburst in 2015. Observations were carried out from 18:34:09 UT on June 15, 2015 until December 2015 in four polarizations and in the four standard
BV RI
filters. The paper presents the results of these observations and a comparative analysis of optical and X-ray data. The observations confirm the previously discovered super-long delays of the optical radiation relative to the X-ray outbursts. Possible mechanisms causing the delay in the optical variations relative to the X-ray variations are discussed. Variability of the optical polarization discovered earlier is confirmed another similar episode reported.
Based on the Chetaev theorem on stable dynamical trajectories in the presence of dissipative forces, we obtain the generalized condition for stability of relativistic classical Hamiltonian systems ...(with an invariant evolution parameter) in the form of the Stückelberg equation. As is known, this equation is the basis of a competing paradigm known as parametrized relativistic quantum mechanics (pRQM). It is shown that the energy of dissipative forces, which generate the Chetaev generalized condition of stability, coincides exactly with Bohmian relativistic quantum potential. Within the framework of Bohmian RQM supplemented by the generalized Chetaev theorem and on the basis of the principle of least action for dissipative forces, we show that the squared amplitude of a wave function in the Stückelberg equation is equivalent to the probability density function for the number of particle trajectories, relative to which the velocity and the position of the particle are not hidden parameters. The conditions for reasonableness of trajectory interpretation of pRQM are discussed. Based on analysis of a general formalism for vacuum-flavor mixing of neutrino within the context of the standard and pRQM models we show that the corresponding expressions for the probability of transition from one neutrino flavour to another differ appreciably, but they are experimentally testable: the estimations of absolute value for neutrino mass based on modern experimental data for solar and atmospheric neutrinos show that the pRQM results have a preference. It is noted that the selection criterion of mass solutions relies on proximity between the average size of condensed neutrino clouds, which is described by the Muraki formula (29th ICRC, 2005) and depends on the neutrino mass, and the average size of typical observed void structure (dark matter + hydrogen gas), which plays the role of characteristic dimension of large-scale structure of the Universe.
We report the results of the experiments on dynamic nuclear polarization (DNP) of (29)Si nuclei under saturation the electron paramagnetic resonance (EPR) transitions of the photoexcited spin S=1 ...states of the oxygen+vacancy complexes in irradiated (29)Si isotopically controlled silicon. The effect of isotope (29)Si abundance on the line width and hyperfine structure of the Si-SL1 EPR spectra was observed. It was shown clearly that the decrease of the (29)Si abundance leads to the transformation the DNP mechanism from the "differential" to "resolved" solid-effect accompanied with the increase of DNP degree. High steady-state (29)Si nuclear polarization of 6% due to "resolved" solid-effect was achieved in silicon crystals with the (29)Si isotope abundance below 4.7%. It was found that the DNP induced by saturation the hyperfine structure EPR lines of triplet centers does not follow the symmetric first derivative EPR line shape, showing the additional contribution to the DNP process.
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