Флуктуационно-диссипативная теорема и частотные моменты функций реакции плотной плазмы на электромагнитное поле

The fluctuation-dissipative theorem and frequency moments for quadratic functions of the reaction of a dense plasma in a constant magnetic field to an electromagnetic field are considered. The frequency moments of the corresponding correlation functions are studied. A model approach is proposed to calculate quadratic reaction functions that determine nonlinear phenomena caused by the quadratic interaction of electromagnetic waves in a dense charged medium (Coulomb systems, plasma) in a constant magnetic field. Keywords: dense plasma, nonlinear fluctuation-dissipative theorem, quadratic reaction functions, nonlinear phenomena.

The effectiveness of complex treatment of acute catarrhal mastitis in cows

The article presents data on the study of the therapeutic efficacy of methods for treating cows with acute catarrhal mastitis. The research was carried out on the basis of 2 cattle farms SPK (collective farm) "Kolos" Myasnikovsky district of Rostov region and individual entrepreneur Head of the peasant (farm) farm AA Berekchiyan Myasnikovsky district of the Rostov region, as well as on the basis of the North Caucasian zonal research veterinary institute - a branch of the Federal State Budgetary Institution "Federal Rostov Agrarian Scientific Center". To study the therapeutic efficacy of the treatment regimen for acute catarrhal mastitis, 2 groups of animals (experimental and control) were also formed according to the principle of analogous pairs, 15 animals each. Control cows were injected with the antibacterial drug amoxicillin LA 15% twice with an interval of 48 hours at the rate of 1 ml of the drug per 10 kg of animal body weight. The drug was administered fractionally, divided into 2 injections. The animals of the experimental group were also injected with the semisynthetic antibiotic amoxicillin LA 15% twice with an interval of 48 hours at the rate of 1 ml of the drug per 10 kg of the animal's body weight. The treatment regimen was supplemented by exposing the animal's body to pulsed low-intensity infrared laser radiation with simultaneous exposure to pulsed incoherent infrared and red radiation and a constant magnetic field in the infiltrate area once a day at the rate of 5 minutes per 10 cm2 of the affected area for 5-7 days. In the course of our research, it was found that therapy for catarrhal mastitis using pulsed low-intensity infrared laser radiation with simultaneous exposure to pulsed incoherent infrared and red radiation and a constant magnetic field in the infiltrate area once a day, as well as the semisynthetic antibiotic amoxicillin LA 15% twice with at intervals of 48 hours showed a high degree of effectiveness. This is confirmed by the rapid recovery of the clinical picture, physiological parameters, and morphological data of the blood of experimental animals. The therapeutic efficiency of the proposed method of treatment was 100%, recovery occurred on average in 3.9 ± 0.15 days. The signs of the inflammatory process disappeared gradually, however, by the 3rd day of treatment, the secretion of milk was completely restored and a significant improvement in the condition of the animals was noted.

Entanglement entropy of inhomogeneous XX spin chains with algebraic interactions

We introduce a family of inhomogeneous XX spin chains whose squared couplings are a polynomial of degree at most four in the site index. We show how to obtain an asymptotic approximation for the Rényi entanglement entropy of all such chains in a constant magnetic field at half filling by exploiting their connection with the conformal field theory of a massless Dirac fermion in a suitably curved static background. We study the above approximation for three particular chains in the family, two of them related to well-known quasi-exactly solvable quantum models on the line and the third one to classical Krawtchouk polynomials, finding an excellent agreement with the exact value obtained numerically when the Rényi parameter α is less than one. When α ≥ 1 we find parity oscillations, as expected from the homogeneous case, and show that they are very accurately reproduced by a modification of the Fagotti-Calabrese formula. We have also analyzed the asymptotic behavior of the Rényi entanglement entropy in the non-standard situation of arbitrary filling and/or inhomogeneous magnetic field. Our numerical results show that in this case a block of spins at each end of the chain becomes disentangled from the rest. Moreover, the asymptotic approximation for the case of half filling and constant magnetic field, when suitably rescaled to the region of non-vanishing entropy, provides a rough approximation to the entanglement entropy also in this general case.

Calculation of energy and magnetic susceptibility of Fe atomic system during dislocation motion in magnetic field

PurposeThe purpose is to calculate the change in the total energy of a small fragment of an idealized lattice of iron (in its pure form and with impurity atoms) containing an edge dislocation during its elementary motion at one interatomic spacing, both under the influence of a constant magnetic field and without it. The introduction of a magnetic field into the system is aimed at checking the adequacy of the description of the phenomenon of magnetoplasticity by changing the total energy of the atomic system.Design/methodology/approachThe design procedure is based on a quantum-mechanical description of the switching process of the covalent bond of atoms in the dislocation core. The authors used the method of density functional theory in the Kohn-Shem version, implemented in the GAUSSIAN 09 software package. Using the perturbation theory, the authors modeled the impact of an external constant magnetic field on the energy of a system of lattice atoms.FindingsThe simulation results confirmed the effect of an external constant magnetic field on the switching energy of the covalent bond of atoms in the dislocation core, and also a change in the magnetic susceptibility of a system of atoms with a dislocation. This complements the description of the magnetoplastic effect during the deformation of metals.Originality/valueThe authors created quantum-mechanical models of the dislocation motion in the Fe crystal lattice: without impurities, with a substitutional atom Cr and with an interstitial atom C. The models take into account the influence of an external constant magnetic field.

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment

In this paper, polymer composites based on polylactide (PLA) and epoxy resin (Epidian 5) were studied in terms of the influence of magnetic induction on their changes in physicochemical properties. The composites contained admixtures in the form of magnetite (Fe3O4) and crystalline cellulose (Avicel PH-1010) in the amount of 10%, 20%, and 30% by weight and starch in the amount of 10%. The admixtures of cellulose and starch were intended to result in the composites becoming biodegradable biopolymers to some extent. Changes in physical and chemical properties due to the impact of a constant magnetic field with a magnetic induction value B = 0.5 T were observed. The changes were observed during tests of tensile strength, bending, impact strength, water absorbency, frost resistance, chemical resistance to acids and bases, as well as through SEM microscopy and with studies of the composition of the composites that use the EDS method and of their structure with the XRD method. Based on the obtained results, it was found that the magnetic induction value changes the properties of composites. This therefore acts as one method of receiving new alternative materials, the degradation of which in the environment would take far less time.