Thin Disk Theory with a Non-Zero Torque Boundary Condition and Comparisons with Simulations

We present an analytical solution for thin disk accretion onto a Kerr black hole that extends the standard Novikov-Thorne alpha-disk in three ways: (i) it incorporates nonzero stresses at the inner edge of the disk, (ii) it extends into the plunging region, and (iii) it uses a corrected vertical gravity formula. The free parameters of the model are unchanged. Nonzero boundary stresses are included by replacing the Novikov-Thorne no torque boundary condition with the less strict requirement that the fluid velocity at the innermost stable circular orbit is the sound speed, which numerical models show to be the correct behavior for luminosities below ~30% Eddington. We assume the disk is thin so we can ignore advection. Boundary stresses scale as alpha*h and advection terms scale as h^2 (where h is the disk opening angle (h=H/r)), so the model is self-consistent when h < alpha. We compare our solution with slim disk models and general relativistic magnetohydrodynamic disk simulations. The model may improve the accuracy of black hole spin measurements.Comment: 11 pages, 8 figures, MNRAS accepte

Simulation of concurrent process with Petri-Markov nets

Abstract. Mathematical apparatus of Petri-Markov nets is described. Petri-Markov simple subnets are introduced. Structures for the simulation of parallelism based on the simple subnets are proposed. Mathematical relationships for the evaluation of the time characteristics of algorithms for a wide class of concurrent computing systems are described. [Ivutin A.N Introduction Currently, a parallelism is a prevailing paradigm of computational processes organisation. In the specialised computer sphere, the idea of parallelism has been used in practice for more than fifty years (CDC-6600 1964 [1] consists of ten independent functional devices operated in parallel), with up-to-date concurrent computations being used in practice in both multi-core processors and computer networks In The methodology of the modelling of concurrent processes was elaborated in the works by C. Petri, W. Reisig, J. Peterson, and V.E

Slim disks around Kerr black holes revisited

We investigate stationary slim accretion disks around Kerr black holes. We construct a new numerical method based on the relaxation technique. We systematically cover the whole parameter space relevant to stellar mass X-ray binaries. We also notice some non-monotonic features in the disk structure, overlooked in previous studies.Comment: 12 pages, 11 figures. The relativistic slim accretion disk solutions have been published online at http://users.camk.edu.pl/as/slimdisk. An appendix containing the manual for the data available online has been added to the previous version of the pape

Parton Distribution Functions of the Charged Pion Within The xFitter Framework

We present the first open-source analysis of parton distribution functions (PDFs) of charged pions using xFitter, an open-source QCD fit framework to facilitate PDF extraction and analyses. Our calculations are implemented at next-to-leading order (NLO) using APPLgrids generated by MCFM generator. Using currently available Drell-Yan and photon production data, we find the valence distribution is well constrained; however, the considered data are not sensitive enough to unambiguously determine sea and gluon distributions. Fractions of momentum carried by the valence, sea and gluon components are discussed, and we compare with the results of JAM collaboration and the GRV group.Comment: 9 pages, 6 figure

Spectra of black hole accretion models of ultraluminous X-ray sources

© 2017 The Authors. We present general relativistic radiation magnetohydrodynamics simulations of super- Eddington accretion on a 10M ☉ black hole. We consider a range of mass accretion rates, black hole spins and magnetic field configurations. We compute the spectra and images of the models as a function of viewing angle and compare them with the observed properties of ultraluminous X-ray sources (ULXs). The models easily produce apparent luminosities in excess of 10 40 erg s -1 for pole-on observers. However, the angle-integrated radiative luminosities rarely exceed 2.5 × 10 39 erg s -1 even for mass accretion rates of tens of Eddington. The systems are thus radiatively inefficient, though they are energetically efficient when the energy output in winds and jets is also counted. The simulated models reproduce the main empirical types of spectra - disc-like, supersoft, soft, hard - observed in ultraluminous X-ray sources (ULXs). The magnetic field configuration, whether 'standard and normal evolution' (SANE) or 'magnetically arrested disc' (MAD), has a strong effect on the results. In SANE models, the X-ray spectral hardness is almost independent of accretion rate, but decreases steeply with increasing inclination. MAD models with non-spinning black holes produce significantly softer spectra at higher values of M●, even at low inclinations. MAD models with rapidly spinning black holes are unique. They are radiatively efficient (efficiency factor ~10-20 per cent), superefficient when the mechanical energy output is also included (70 per cent) and produce hard blazar-like spectra. In all models, the emission shows strong geometrical beaming, which disagrees with the more isotropic illumination favoured by observations of ULX bubbles

Russian Cross-disciplinary Consensus on the diagnosis and treatment of spondyloarthritis associated with inflammatory bowel diseases

The Russian Cross-disciplinary Consensus on the diagnositic and treatment of spondyloarthritis (SpA) in inflammatory bowel diseases (IBD) was prepared on the initiative of the Loginov Moscow Clinical Scientific Center, using the Delphic system. Its purpose was to consolidate the opinions of experts on the most actual issues of diagnosis and treatment of concomitant immuno-inflammatory diseases (SpA and IBD). An interdisciplinary approach is provided by the participation of leading gastroenterologists and rheumatologists. The working group analyzed domestic and foreign publications on the problem of curation of patients with SpA and IBD. There have been 17 statements and 2 treatment algorithms formulated. Statements 1–3 reflect the fundamental principles of management of patients with SpA and IBD. The principles of early diagnosis of SpA and IBD, including the diagnosis of complications of therapy, are described below. Eleven statements are devoted to current methods of treatment, on the basis of which 2 treatment algorithms have been developed. The statements of the Consensus were submitted to the Expert Council for consideration, edits were made, after which an online vote took place. This paper presents current recommendations for the management, diagnosis and treatment of patients with SpA and IBD

The Iron Age Pottery Assemblages of the Settlement "Panovo Hillfort"

The paper includes into the scientific circulation the materials received during the excavations of the Panovo station in 1925 by B.S. Zhukov. "Panovo hillfort" is a monument of multiple settling, at first this place was inhabited in Neolithic, then in the Bronze Age it was populated by the bearers of Chirki cultural traditions. In the final Bronze Age settlement appears here, associated with the bearers of textile ceramics traditions, at the initial stage of the Early Iron Age occupied by the representatives of the Akozino culture ACHA (Ananyino Cultural and Historical Area). In VII-V centuries BC the settlement was included into the circle of monuments of Vyatka-Vetluga culture ACHA. The materials obtained during the excavations of the settlement are a valuable source for understanding the processes of development of the Vetluga River basin by the Ananyino communities as well as the interaction between the bearers of different cultural traditions within the Ananyino world itself. In IV/III-III centuries BC in this site the bearers of Gorodetz culture appear. The final stage of developing of the site falls at the end of the I millennium BC - first half of the I millennium AD and at the middle - third quarter of the I millennium AD. Different ceramic traditions, following each other, are fixed at the settlement of this period. The finds clearly reflect the above-mentioned stages of developing of the site. It is important to note that the settlements of the first half of the I millennium AD in the forest territories of the Transvolga region are very little known today, not enough materials have been collected and they are still poorly studied, and therefore the use the excavation materials from the settlement "Panovo hillfort" is relevant

Prospects for Reducing Accidents on the Roads of the Russian Federation Using the Scientific and Methodological Approach

This article reports the results of an in-depth analysis of the transport situation in the Russian Federation and presents the main programmes, aimed at its improvement. The paper deals with the major ways of reducing risk of traffic accidents and increasing traffic safety. The paper proposes the scientific and methodological approach, providing the specialists with the opportunities of conducting a comprehensive assessment of the causes of emergencies and aiming at eliminating road accidents rates. The origin of the process of an emergency situation occurrence has been investigated and designed, the key components (constituents) of the process have been identified and the basic mechanisms, influencing the basic components, have been analyzed. The algorithm of the application of the proposed and developed scientific and methodological approach at the level of departmental organizations has been suggested. The article describes the mathematical model of the process of emergency situations occurrence, which, together with the applied telematics systems and intelligent transport systems, will help to achieve the basic objectives of the study

Prospects for Reducing Accidents on the Roads of the Russian Federation Using the Scientific and Methodological Approach

This article reports the results of an in-depth analysis of the transport situation in the Russian Federation and presents the main programmes, aimed at its improvement. The paper deals with the major ways of reducing risk of traffic accidents and increasing traffic safety. The paper proposes the scientific and methodological approach, providing the specialists with the opportunities of conducting a comprehensive assessment of the causes of emergencies and aiming at eliminating road accidents rates. The origin of the process of an emergency situation occurrence has been investigated and designed, the key components (constituents) of the process have been identified and the basic mechanisms, influencing the basic components, have been analyzed. The algorithm of the application of the proposed and developed scientific and methodological approach at the level of departmental organizations has been suggested. The article describes the mathematical model of the process of emergency situations occurrence, which, together with the applied telematics systems and intelligent transport systems, will help to achieve the basic objectives of the study.</jats:p