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We present multiwavelength observations and a model for flat spectrum radio quasar NVSS J141922-083830, originally classified as a blazar candidate of unknown type (BCU II object) in the Third Fermi-LAT AGN Catalog (3LAC). Relatively bright flares (>3 magnitudes) were observed on 21 February 2015 (MJD 57074) and 8 September 2018 (MJD 58369) in the optical band with the MASTER Global Robotic Net (MASTER-Net) telescopes. Optical spectra obtained with the Southern African Large Telescope (SALT) on 1 March 2015 (MJD 57082), during outburst, and on 30 May 2017 (MJD 57903), during quiescence, showed emission lines at 5325\r{A} and at $\approx$3630\r{A} that we identified as the Mg II 2798\r{A} and C III] 1909\r{A} lines, respectively, and hence derived a redshift z = 0.903. Analysis of Fermi-LAT data was performed in the quiescent regime (5 years of data) and during four prominent flaring states in February-April 2014, October-November 2014, February-March 2015 and September 2018. We present spectral and timing analysis with Fermi-LAT. We report a hardening of the gamma-ray spectrum during the last three flaring periods, with a power-law spectral index $\Gamma = 2.0$-$2.1$. The maximum gamma-ray flux level was observed on 24 October 2014 (MJD 56954) at $(7.57 \pm 1.83) \times 10^{-7}$ ph~cm$^{-2}$s$^{-1}$. The multi-wavelength spectral energy distribution during the February-March 2015 flare supports the earlier evidence of this blazar to belong to the FSRQ class. The SED can be well represented with a single-zone leptonic model with parameters typical of FSRQs, but also a hadronic origin of the high-energy emission can not be ruled out., Comment: 15 pages, 11 figures, 8 tables, accepted for publication in MNRAS (29 July 2022)

Gamma-ray bursts (GRBs) are bright extragalactic flashes of gamma-ray radiation and briefly the most energetic explosions in the Universe. Their catastrophic origin (the merger of compact objects or the collapse of massive stars) drives the formation of a newborn compact remnant (black hole or magnetar) that powers two highly relativistic jets. To distinguish between magnetized and baryonic jet models and ultimately determine the power source for these energetic explosions, our team studies the polarization of the light during the first minutes after the explosion (using novel instruments on fully autonomous telescopes around the globe) to directly probe the magnetic field properties in these extragalactic jets. This technology allowed the detection of highly polarized optical light in GRB 120308A and confirmed the presence of mildly magnetized jets with large-scale primordial magnetic fields in a reduced sample of GRBs (e.g. GRB 090102, GRB 110205A, GRB 101112A, GRB 160625B). Here we discuss the observations of the most energetic and first GRB detected at very high TeV energies, GRB 190114C, which opens a new frontier in GRB magnetic field studies suggesting that some jets can be launched highly magnetized and that the collapse and destruction of these magnetic fields at very early times may have powered the explosion itself. Additionally, our most recent polarimetric observations of the jet of GRB 141220A indicate that, when the jetted ejected material is decelerated by the surrounding environment, the magnetic field amplification mechanisms at the front shock (needed to generate the observed synchrotron emission) produce small magnetic domains. These measurements validate theoretical expectations and contrast with previous observations that suggest large magnetic domains in collisionless shocks (i.e. GRB 091208B)., To appear in the Proceedings of the 16th Marcel Grossmann Meeting (July 5-10, 2021)

Full list of authors: Buckley, D. A. H.; Bagnulo, S.; Britto, R. J.; Mao, J.; Kann, D. A.; Cooper, J.; Lipunov, V.; Hewitt, D. M.; Razzaque, S.; Kuin, N. P. M.; Monageng, I. M.; Covino, S.; Jakobsson, P.; van der Horst, A. J.; Wiersema, K.; Böttcher, M.; Campana, S.; D'Elia, V.; Gorbovskoy, E. S.; Gorbunov, I.; Groenewald, D. N.; Hartmann, D. H.; Kornilov, V. G.; Mundell, C. G.; Podesta, R.; Thomas, J. K.; Tyurina, N.; Vlasenko, D.; van Soelen, B.; Xu, D., We report on results of spectropolarimetry of the afterglow of the long gamma-ray burst GRB 191221B, obtained with SALT/RSS and VLT/FORS2, as well as photometry from two telescopes in the MASTER Global Robotic Network, at the MASTER-SAAO (South Africa) and MASTER-OAFA (Argentina) stations. Prompt optical emission was detected by MASTER-SAAO 38 s after the alert, which dimmed from a magnitude (white-light) of ∼10-16.2 mag over a period of ∼10 ks, followed by a plateau phase lasting ∼10 ks and then a decline to ∼18 mag after 80 ks. The light curve shows complex structure, with four or five distinct breaks in the power-law decline rate. SALT/RSS linear spectropolarimetry of the afterglow began ∼2.9 h after the burst, during the early part of the plateau phase of the light curve. Absorption lines seen at ∼6010 and 5490 Å are identified with the Mg ii 2799 Å line from the host galaxy at z = 1.15 and an intervening system located at z = 0.96. The mean linear polarization measured over 3400-8000 Å was ∼1.5 per cent and the mean equatorial position angle (θ) was ∼65°. VLT/FORS2 spectropolarimetry was obtained ∼10 h post-burst, during a period of slow decline (α = -0.44), and the polarization was measured to be p = 1.2 per cent and θ = 60°. Two observations with the MeerKAT radio telescope, taken 30 and 444 d after the GRB trigger, detected radio emission from the host galaxy only. We interpret the light curve and polarization of this long GRB in terms of a slow-cooling forward shock. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society., Some of the observations presented here were obtained with SALT under programme 2018-2-LSP-001 (PI: DAHB), which is supported by Poland under grant no. MNiSW DIR/WK/2016/07. Based on observations collected at the European Southern Observatory under ESO programme 0104.D-0600(C). DAHB and JT acknowledge support through the National Research Foundation (NRF) of South Africa. MB is supported by the South African Research Chairs Initiative (grant no. 64789) of the Department of Science and Innovation and the NRF.5 DMH acknowledges financial support from the NRF and the SAAO. SR is partially supported by NRF with grant no. 111749 (CPRR) and by a University of Johannesburg Research Council grant. DAK acknowledges support from Spanish National Research Project RTI2018-098104-J-I00 (GRBPhot). NPMK acknowledges support by the UK Space Agency. MASTER (equipment) is supported by Lomonosov Moscow State University Development Program. VL and DV are supported by RFBR grant 19-29-11011. CGM acknowledges financial support from Hiroko and Jim Sherwin. We thank the Director and staff of SARAO for supporting our MeerKAT DDT observation. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. Based on observations made with the SALT and the MeerKAT radio telescope array., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

Problems arising in coke-battery operation are considered. The equivalent age of coke batteries may be determined by taking account of their technical state and their operating conditions and calculating the starting time for their major repair or complete reconstruction.

Full list of authors: Gupta, Rahul; Gupta, S.; Chattopadhyay, T.; Lipunov, V.; Castro-Tirado, A. J.; Bhattacharya, D.; Pandey, S. B.; Oates, S. R.; Kumar, Amit; Hu, Y. -D.; Valeev, A. F.; Minaev, P. Yu; Kumar, H.; Vinko, J.; Dimple; Sharma, V.; Aryan, A.; Castellón, A.; Gabovich, A.; Moskvitin, A.; Ordasi, A.; Pál, A.; Pozanenko, A.; Zhang, B. -B.; Kumar, B.; Svinkin, D.; Saraogi, D.; Vlasenko, D.; Fernández-García, E.; Gorbovskoy, E.; Anupama, G. C.; Misra, K.; Sárneczky, K.; Kriskovics, L.; Castro-Tirado, M. Á.; Caballero-García, M. D.; Tiurina, N.; Balanutsa, P.; Lopez, R. R.; Sánchez-Ramírez, R.; Szakáts, R.; Belkin, S.; Guziy, S.; Iyyani, S.; Tiwari, S. N.; Vadawale, Santosh V.; Sun, T.; Bhalerao, V.; Kornilov, V.; Sokolov, V. V., Multipulsed GRB 190530A, detected by the Gamma-ray Burst Monitor (GBM) and Large Area Telescope onboard Fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric analysis of the prompt emission observed using AstroSat and Fermi to provide insight into the prompt emission radiation mechanisms. The time-integrated spectrum shows conclusive proof of two breaks due to peak energy and a second lower energy break. Time-integrated (55.43 ± 21.30 per cent) as well as time-resolved polarization measurements, made by the Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat, show a hint of high degree of polarization. The presence of a hint of high degree of polarization and the values of low energy spectral index (αpt) do not run over the synchrotron limit for the first two pulses, supporting the synchrotron origin in an ordered magnetic field. However, during the third pulse, αpt exceeds the synchrotron line of death in few bins, and a thermal signature along with the synchrotron component in the time-resolved spectra is observed. Furthermore, we also report the earliest optical observations constraining afterglow polarization using the MASTER (P < 1.3 per cent) and the redshift measurement (z = 0.9386) obtained with the 10.4 m GTC (Gran Telescopio Canarias) telescopes. The broad-band afterglow can be described with a forward shock model for an ISM (interstellar medium)-like medium with a wide jet opening angle. We determine a circumburst density of n0 ∼ 7.41, kinetic energy EK ∼ 7.24 × 1054 erg, and radiated gamma-ray energy Eγ,iso ∼ 6.05 × 1054 erg. © 2022 The Author(s)., RG, DB, SBP, KM, and VB acknowledge BRICS grant DST/IMRCD/BRICS/PilotCall1/ProFCheap/2017(G) for the financial support. This publication uses data from the AstroSat mission of the Indian Space Research Organisation (ISRO), archived at the Indian Space Science Data Centre (ISSDC). CZT-Imager is built by a consortium of institutes across India, including the Tata Institute of Fundamental Research (TIFR), Mumbai, the Vikram Sarabhai Space Centre, Thiruvananthapuram, ISRO Satellite Centre (ISAC), Bengaluru, Inter University Centre for Astronomy and Astro-physics, Pune, Physical Research Laboratory, Ahmedabad, and Space Application Centre, Ahmedabad. This research also has used data obtained through the HEASARC Online Service, provided by the NASA-GSFC, in support of NASA High Energy Astrophysics Programmes. This work is based on data from the OSN Public Archive at IAA (IAA-CSIC) and the CAHA Archive at CAB (INTA-CSIC). The MASTER equipment is supported by Lomonosov MSU Development Programme. VL and VK are supported by RFBR 19-29-11011 grant. The research group of JV is supported by the project ‘Transient Astrophysical Objects’ GINOP 2.3.2-15-2016-00033 of the National Research, Development and Innovation Office (NKFIH), Hungary, funded by the European Union. AA acknowledges funds and assistance provided by the Council of Scientific and Industrial Research (CSIR), India with file number 09/948(0003)/2020-EMR-I. AP, SB, and PM acknowledge a support of the RSCF grant 18-12-00378. The GROWTH India Telescope (GIT) is a 70 cm telescope with a 0.7 deg field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the IAO (Hanle), operated by the Indian Institute of Astrophysics (IIA). MCG acknowledges support from the Ramón y Cajal Fellowship RYC2019-026465-I. YDH acknowledges support under the additional funding from the RYC2019-026465-I. BBZ acknowledges support by the National Key Research and Development Programme of China (2018YFA0404204), the National Natural Science Foundation of China (grant numbers 11833003, U2038105, and 12121003), the science research grants from the China Manned Space Project with NO.CMS-CSST-2021-B11, and the Programme for Innovative Talents, Entrepreneur in Jiangsu. RSM acknowledges support under the CSIC-MURALES project with reference 20215AT009., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

GRB 190829A at z=0.0785 is the fourth closest long GRB ever detected by the Neil Gehrels Swift observatory, and the third confirmed case with a very high energy component. We present our multi-wavelength analysis of this rare event, focusing on its early stages of evolution, and including data from Swift, the MASTER global network of optical telescopes, ALMA, and ATCA. We report sensitive limits on the linear polarization of the optical emission, disfavouring models of off-axis jets to explain the delayed afterglow peak. The study of the multi-wavelength light curves and broadband spectra supports a model with at least two emission components: a bright reverse shock emission, visible at early times in the optical and X-rays and, later, in the radio band; and a forward shock component dominating at later times and lower radio frequencies. A combined study of the prompt and afterglow properties shows many similarities with cosmological long GRBs, suggesting that GRB 190829A is an example of classical GRBs in the nearby universe., Comment: 13 pages, 8 figures, accepted for publication in MNRAS

The problems arising in the operation of coke battery 3 at Rourkela Steel Plant (India) are considered. The design of coke battery 3 is described. It has an Otto system; the capacity of a single coking chamber is 21.6 m3. Hybrid heating is employed, and heating gas is supplied to the bottom of the chamber. A method is proposed for hydraulic regulation of the coke battery with unidirectional heating-gas input and product output.

The paper presents an analysis of the failures of components of the mechanical part of 2ES6 Sinara main electric locomotives in operation at the West Siberian Railway operating domain. The causes and consequences of failures of the most vulnerable components are determined. The task is to determine the level of dynamic loading in the “bogie – rod - traction electric motor” subsystem to reduce the dynamic effects in the “locomotive - track” system. The urgency of the problem of increased dynamic loading of components of the mechanical part is proved, and a mathematical model of vertical oscillations of traction rolling stock is formed on the basis of the second-order Lagrange equation in the form of a system of equations that allows assessing the load of components in operation. The spectral density of random perturbations was chosen—an approximation of random perturbations using the spectral density of the track roughness of Professor A. I. Belyaev. Using a computer, values were calculated, and graphs of the amplitude-frequency characteristics of vertical displacements, maximum accelerations of the body, bogie, traction electric motor and wheelset of the considered conditional uniaxial electric locomotive were built. A comparative analysis of the calculation results and empirical data is carried out. The task is to change the existing design of the suspension system of the traction electric motor of the electric locomotive under consideration and to analyze the oscillations of its components in further studies.

Operational problems at coke battery 6 of Rourkela Steel Plant in India are considered. The structure of coke battery 6 of PVR type (useful capacity of the coke ovens 41.6 m3) is described; it is characterized by bottom supply of the heating gas and hybrid heating. Removing the scale buildup from the inclined section of the heating channels improves the thermal and hydraulic conditions, extends coke-battery life, and eliminates nonuniform heating of the coke cake.

The results of LIGO/Virgo S200302c (O3) error-box optical inspection by MASTER are presented. We observed 4242 square degrees square degrees inside 3σ error box during 1 month. We present MASTER OT J141401.39–483305.7, MASTER OT J215856.95–392909.6, MASTER OT J061642.05+435617.9, MASTER OT J052817.95+672801.4—optical transients found by the MASTER auto-detection system during this inspection as the result of a survey of large error-fields, indicating the efficiency of MASTER observational strategy.

We present MASTER observations from inspecting the large error-box associated with LIGO/Virgo G270590, and our observational strategy. MASTER observed 6292 square degrees inside the 3σ error box. We present new optical sources detected during this inspection.

We present the results of MASTER Global Robotic Net optical observations of the region within the LIGO/Virgo S200219ac error-box, triggered during the O3 run. We observed 1124 square degrees inside the 3σ error box during a half month. We present the identified optical transients found during this study, which are not related to gravitational waves, and briefly discuss the MASTER observation strategy.

We present the results of MASTER Global Robotic Net optical observations of the LIGO GW170104 error-box during the LIGO/Virgo O2 run. We observed 3421 square degrees inside 3σ error-field. Dozens of optical transients unrelated to gravitational waves were discovered as the result of MASTER observation strategy, that we presented, including short very bright MASTER optical transients J133017.28+780951.8.

Problems arising in the reconstruction of coke battery 1 at Isfahan steel plant are considered. The construction of coke battery 1 (coke-oven capacity 27.3 m3) with a PVR-51 dust-free coke-discharge system and bottom heating-gas supply is described. The losses of unprocessed coke-oven gas are calculated after coke-battery startup and after the elimination of leaks at seams in the refractory lining. Introduction of a method of detecting leaks at lining seams in the coke-oven walls reduces the losses of unprocessed coke-oven gas from 1738.73 to 44.6 m3/h.

The reconstruction of coke battery 1 at Isfahan steelworks is considered. The construction of a PVR-51 system at coke battery 1 (useful oven capacity 27.3 m3, with lower heating-gas supply, is described. The automatic temperature-monitoring system for coke-battery heating by coke-oven gas is discussed. The gas motion in battery heating with internal furnaces is considered. A system for temperature regulation and maintenance in the upper heating channels is proposed.

Problems in the operation of coke battery 6 at Rourkela Steel Plant (India) are analyzed. Coke battery 6 is of PVR-51 type, with heating-gas supply at the bottom, and consists of 41.6-m3 ovens; combined heating is employed. The use of a stainless-steel sleeve to eliminate the leaking of heating gas (coke-oven gas) from the hearth channels at the slipping seams is described. This extends battery life and eliminates the leakage of coke-oven gas.

Problems arising in the operation of coke battery 2 at Isfahan steel plant (Iran) are considered. The reinforcement of coke battery 2 (chamber capacity 27.3 m3) is considered; heating gas is supplied to the bottom of the battery, which is equipped with a PVR-51 dust-free discharge system. Repair of the reinforcement without disassembly is proposed, so as to extend its working life before replacement.

The reconstruction of coke battery 1 at Isfahan Steel Works is considered. The structure of the Dinas component in the insulating walls at coke battery 1 with a PVR-51 system is described; this battery has bottom supply of the heating gas; the useful volume of a single oven is 27.3 m3. The research shows that drying and heating of the Dinas component by a burner with a protective casing protects the refractory surface of the insulating wall from an open flame during heating from 20 to 500°C.