Precision calculation of energy levels for four-valent Si I

We report results of the calculation of the low-lying levels of neutral Si using a combination of the configuration interaction and many-body perturbation theory (CI+MBPT method). We treat Si I as an atom with four valence electrons and use two different starting approximations, namely $V^{N-2}$ and $V^{N-4}$. We conclude that both approximations provide comparable accuracy, on the level of 1%

Calculation of francium hyperfine anomaly

The Dirac-Hartree-Fock plus many-body perturbation theory (DHF+MBPT) method has been used to calculate hyperfine structure constants for Fr. Calculated hyperfine structure anomaly for hydrogen-like ion has been shown to be in good agreement with analytical expressions. It has been shown that the ratio of the anomalies for $s$ and $p_{1/2}$ states is weakly dependent on the principal quantum number. Finally, we estimate Bohr--Weisskopf corrections for several Fr isotopes. Our results may be used to improve experimental accuracy for the nuclear $g$ factors of short-lived isotopes.Comment: 5 pages, 3 tables, 2 figures. arXiv admin note: text overlap with arXiv:1703.1004

Spatial sequencing of microbial reduction of chromate and nitrate in membrane bioreactor

Sequential reduction of chromate and nitrate, two competitive electron acceptors, has been demonstrated for strains of Pseudomonas genus for both planktonic cells and cells immobilised in agar layers on the surface of synthetic membrane. Denitrification occurs practically after chromate depletion. This order of reduction process is consistent with redox potentials of the respective reactions. In a membrane bioreactor, competitive inhibition results in nitrate transfer through the membrane without transformation. Thus the receiving phase is contaminated with nitrate. To address this problem, a membrane has been used for spatial sequencing of chromate and nitrate reduction. Bacterial cells were immobilised in two layers with each layer placed on opposing sides of the membrane. By this means, chromate reduction is localised into the layer contacting the feed phase while nitrate reduction occurs in the layer facing the receiving phase. As a result, only traces of the pollutants are detected in the receiving phase.Міжнародний благодійний фонд відродження Києво-Могилянської академі

A uniqueness result for the inverse problem of identifying boundaries from weighted Radon transform

We study the problem of the integral geometry, in which the functions are integrated over hyperplanes in the $n$-dimensional Euclidean space, $n=2m+1$. The integrand is the product of a function of $n$ variables called the density and weight function depending on $2n$ variables. Such an integration is called here the weighted Radon transform, which coincides with the classical one if the weight function is equal to one. It is proved the uniqueness for the problem of determination of the surface on which the integrand is discontinuous.Comment: 10 pages, 1 figur

Problems of research of speech activities of bilingual students in the context of contemporary linguistic situation

Situation of bilinguism is discussed on the basis of people speaking both Armenian (native for the person or his/her ancestors) and Russian. One of the languages is, as a rule, dominating in the mind of the bilingual person, it “forces out” the second, though the ideal situation may occur when both languages are equal, their usage is accompanied by meta-language reflection on both of them, their differences and similarities.Рассматривается ситуация билингвизма на примере людей, владеющих как армянским (родным для себя или предков), так и русским языками. Демонстрируется, что, как правило, один из языков в сознании билингва является доминирующим, «вытесняет» другой, хотя наблюдается и ситуация, признаваемая идеальной, – равное владение обоими языками, сопровождающееся метаязыковой рефлексией по поводу каждого из них, их сходства и различия

Functional reserves of students related to a special medical group for health reasons

The relevance of this work is determined by the high prevalence of physical inactivity among students assigned to a special medical group for health reasons. The purpose of the study is to analyze the impact of physical education in a special medical group on the functional reserves of students’ body. A group of 20 first-year students was observed. Girls were engaged in physical culture during one school year. The examination at the beginning and end of the observation period included anthropometry, physiometry and functional testing. The heart rate and respiration rate in most girls exceeded the upper limit of the physiological norm; the vital capacity of the lungs did not reach the lower limit of the norm during initial testing. Functional tests showed low results. Statistically significant decrease heart rate and respiration rate increasing the lung capacity was found on re-examination. The results of the functional test have improved. The results obtained led to the conclusion that body’s functional reserves are reduced in students assigned to a special medical group for health reasons. Feasible physical culture classes are accompanied by the expansion of the body’s functional reserves. &nbsp