Differential Neutrino Rates and Emissivities from the Plasma Process in Astrophysical Systems

The differential rates and emissivities of neutrino pairs from an equilibrium plasma are calculated for the wide range of density and temperature encountered in astrophysical systems. New analytical expressions are derived for the differential emissivities which yield total emissivities in full agreement with those previously calculated. The photon and plasmon pair production and absorption kernels in the source term of the Boltzmann equation for neutrino transport are provided. The appropriate Legendre coefficients of these kernels, in forms suitable for multi-group flux-limited diffusion schemes are also computed.Comment: 27 pages and 10 figures. Submitted to Phys. Rev.

The photo-neutrino process in astrophysical systems

Explicit expressions for the differential and total rates and emissivities of neutrino pairs from the photo-neutrino process $e^\pm + \gamma \to e^\pm + \nu + \bar\nu$ in hot and dense matter are derived. Full information about the emitted neutrinos is retained by evaluating the squared matrix elements for this process which was hitherto bypassed through the use of Lenard's identity in obtaining the total neutrino emissivities. Accurate numerical results are presented for widely varying conditions of temperature and density. Analytical results helpful in understanding the qualitative behaviors of the rates and emissivities in limiting situations are derived. The corresponding production and absorption kernels in the source term of the Boltzmann equation for neutrino transport are developed. The appropriate Legendre coefficients of these kernels, in forms suitable for multigroup flux-limited diffusion schemes are also provided.Comment: 26 pages and 7 figures. Version as accepted in Phys. Rev. D; three figures and related discussion revise

Один из способов управления технологическим процессом дуговой сталеплавильной печи

В статье приводится описание комплексной математической модели, используемой для рационального управления работой дуговых электросталеплавильных печей.In article the description of the complex mathematical model used for rational management by work of arc electrosteel-smelting furnaces is resulted

Baikal-GVD

We present the status of the Gigaton Volume Detector in Lake Baikal (Baikal-GVD) designed for the detection of high energy neutrinos of astrophysical origin. The telescope consists of functionally independent clusters, sub-arrays of optical modules (OMs), which are connected to shore by individual electro-optical cables. During 2015 the GVD demonstration cluster, comprising 192 OMs, has been successfully operated in Lake Baikal. In 2016 this array was upgraded to baseline configuration of GVD cluster with 288 OMs arranged on eight vertical strings. Thus the instrumented water volume has been increased up to about 5.9 Mtons. The array was commissioned in early April 2016 and takes data since then. We describe the configuration and design of the 2016 array. Preliminary results obtained with data recorded in 2015 are also discussed

Assessment of possibilities of transmission polarization mapping for the characterization of sclera macrostructure

The purpose of the study is to assess possibilities of applying the method of transmission polarization mapping for characterization of sclera structure. Material and methods. In the work, samples of rat, rabbit, porcine, and human sclera were examined. Samples of the human sclera were taken (enucleation of the eyeball) from patients with diagnoses: terminal painful glaucoma, subatrophy of the eyeball. From the enucleated eyes, sclera samples were taken from the posterior pole of the eye and from the equator. The sample transparency required for carrying out transmission polarization mapping in thick samples was achieved using immersion optical clearing, 85% and 50% aqueous glycerol solutions and 40% aqueous glucose solution being used as immersion agents. The polarization mapping system used in this work was assembled on the basis of a polarization microscope equipped with a measuring video camera. Re-sults. It is shown that the method of transmission polarization mapping can be used to measure the parameters of the orientational order of scleral collagen fibers, mapping of human sclera samples requiring conduction of the polarization measurements under optical clearing conditions. Since the disorganization of collagen structures of eye connective tissue can be considered as the initial stage of glaucoma process, the technique of transmission polarization mapping can be used as a basis for in vitro studies of the pathogenesis of primary open-angle glaucoma. Conclusion. The potential and limitations of polarization mapping in studying sclera structure in vitro have been established.</p

Using machine learning for recognition of text patterns of literary sources

Background. Today, in the field of artificial intelligence, there are natural language processing technologies, the purpose of which is to solve problems in such areas as machine translation, text sentiment analysis and text classification. In the article, within the framework of the problem of recognition of text patterns, the application of machine learning and data mining methods is considered. The object of the study is the types of literary sources. The subject of the research is the classification of literary sources using machine learning methods. The purpose of the work is to compare the effectiveness of machine learning methods in solving the problem of binary classification of literary sources and to identify the distinctive features inherent in each of them. Materials and methods. Classification of literary sources using the Naive Bayes classifier and Logistic regression, and the Bag of Words and TF-IDF methods. Results. A comparative analysis of the obtained models was carried out. The model with which the Logistic regression and the Bag of Words method were used together demonstrates the greatest efficiency. Conclusions. Logistic regression and the Bag of Words method demonstrated the greatest efficiency when working with text templates, while the use of stemmization and lemmatization did not affect the final model efficiency indicator. The second type of literary sources contains text constructions unique to it, such as “[Electronic resource]” or “date of access”, which increase the chance of correct classification

Thermal and Electric Conductivities of Coulomb Crystals in the Inner Crust of a Neutron Star

Thermal and electric conductivities of relativistic degenerate electrons are calculated for the case when electrons scatter by phonons in Coulomb crystals made of spherical finite--size nuclei at densities 10 11 g/cm 3 ! ¸ ae ! ¸ 10 14 g/cm 3 , corresponding to the inner crust of a neutron star. In combination with the results of the previous article (for lower ae), simple unified fits are obtained which describe the kinetic coefficients in the range 10 3 g/cm 3 ! ¸ ae ! ¸ 10 14 g/cm 3 , for matter with arbitrary nuclear composition. The results are valid for studying thermal evolution of neutron stars and evolution of their magnetic fields. The difference between the kinetic coefficients in the neutron star crust composed of ground state and accreted matters is analyzed. Thermal drift of the magnetic field in the neutron star crust is discussed. Accepted for publication in Astronomy Letters, v. 22, 1996 2 1 INTRODUCTION The thermal end electrical conductivi..