Complex potentials: bound states, quantum dynamics and wave operators

Schr\"odinger operator on half-line with complex potential and the corresponding evolution are studied within perturbation theoretic approach. The total number of eigenvalues and spectral singularities is effectively evaluated. Wave operators are constructed and a criterion is established for the similarity of perturbed and free propagators.Comment: 9 page

Spectral multiplicity for powers of weakly mixing automorphisms

We study the behavior of maximal multiplicities $mm (R^n)$ for the powers of a weakly mixing automorphism $R$. For some special infinite set $A$ we show the existence of a weakly mixing rank-one automorphism $R$ such that $mm (R^n)=n$ and $mm(R^{n+1}) =1$ for all $n\in A$. Moreover, the cardinality $cardm(R^n)$ of the set of spectral multiplicities for $R^n$ is not bounded. We have $cardm(R^{n+1})=1$ and $cardm(R^n)=2^{m(n)}$, $m(n)\to\infty$, $n\in A$. We also construct another weakly mixing automorphism $R$ with the following properties: $mm(R^{n}) =n$ for $n=1,2,3,..., 2009, 2010$ but $mm(T^{2011}) =1$, all powers $(R^{n})$ have homogeneous spectrum, and the set of limit points of the sequence $\{\frac{mm (R^n)}{n} : n\in \N \}$ is infinite

Properties of anti-corrosive ferrite pigment synthesized with the use of production waste

© 2018, International Multidisciplinary Scientific Geoconference. All rights reserved. Pigments of the inhibitory type are the active principle of most primers used to protect metals from corrosion. Developers of anticorrosive paint and varnish materials seek to replace chromium-containing pigments, which widely used until recently due to their toxicity, with more environmentally appropriate choices. These include ferrite pigments. It is known, that the most spread method for the synthesis of ferrites, which are complex oxides or salts of ferrous acid, is the joint calcination of iron oxides with oxides having basic properties. The aim of this work is an expansion of the raw material base to produce ferritic pigments by using as one of the initial components an aspiration dust (content of iron oxide exceeds 70 %) formed as a waste in steel-casting plants. Crushed brucite (natural magnesium oxide) was used as the second component. After their thorough mixing, the resulting mixture was calcined at the reaction temperature: MgО + Fe2O3 → MgFe2O4 (1) 6MgО + 4Fe3O4 + О2 → 6MgFe2O4 (2) with obtaining of magnesium ferrite. The course of the reaction was controlled by thermogravimetry and differential thermal analysis. Ferritic-magnetite structure formation was recorded by X-ray diffraction analysis. The variation of the synthesis’s temperature-time conditions made it possible to find the optimal parameters for obtaining ferrite. The synthesized ferrite was ground on a planetary mill. The studying of the painting and technical properties of the grinding product showed that it can be used as a pigment in the production of paints and varnishes. The results of electrochemical studies of steel in contact with the aqueous extract of ferritic pigment containing 3% of sodium chloride led to the conclusion of the high ability of the resulting product to inhibit the corrosion processes

Biofriendly nanocomposite containers with inhibition properties for the protection of metallic surfaces

© 2017 The Author(s) Published by the Royal Society. All rights reserved.An attempt to combine two 'green' compounds in nanocomposite microcontainers in order to increase protection properties of waterborne acryl-styrene copolymer (ASC) coatings has been made. Nlauroylsarcosine (NLS) served as a corrosion inhibitor, and linseed oil (LO) as a carrier-forming component. LO is compatible with this copolymer and can impart to the coating self-healing properties. For the evaluation of the protective performance, three types of coatings were compared. In the first two, NLS was introduced in the coating formulation in the forms of free powder and micro-containers filled with LO, correspondingly. The last one was a standard ASC coating without inhibitor at all. Low-carbon steel substrates were coated by these formulations by spraying and subjected subsequently to the neutral salt spray test according to DIN ISO 9227. Results of these tests as well as the data obtained by electrochemical study suggest that such containers can be used for the improvement of adhesion of ASC-based coatings to the substrate and for the enhancement of their protective performance upon integrity damage, whereas the barrier properties of intact coatings were decreased

HIERARCHICAL ONTOLOGY OF THE BASIC CONCEPTS OF HARDWARE, INFORMATION AND MANAGEMENT SUPPORT FOR THE CONDITION OF A CARDIAC SURGICAL SUTURE

The proposed topic includes the development of classification systems and structuring of the basic concepts associated with cardiac surgical sutures to ensure the expected process of information management and quality care for patients with cardiovascular diseases

MHD alpha^2-dynamo, Squire equation and PT-symmetric interpolation between square well and harmonic oscillator

It is shown that the alpha^2-dynamo of Magnetohydrodynamics, the hydrodynamic Squire equation as well as an interpolation model of PT-symmetric Quantum Mechanics are closely related as spectral problems in Krein spaces. For the alpha^2-dynamo and the PT-symmetric model the strong similarities are demonstrated with the help of a 2x2 operator matrix representation, whereas the Squire equation is re-interpreted as a rescaled and Wick-rotated PT-symmetric problem. Based on recent results on the Squire equation the spectrum of the PT-symmetric interpolation model is analyzed in detail and the Herbst limit is described as spectral singularity.Comment: 21 pages, LaTeX2e, 10 figures, minor improvements, references added, to appear in J. Math. Phy

Синтез азометинов на основе производных 4-аминобензолсульфамида

Synthesis of (£)-azomethines, derivatives of 4-aminobenzenesulfonamide (Streptocidum), by condensation of substituted vanillin-like benzaldehydes with streptocidum in methanol, has been described.Представлен синтез функционально замещенных ароматических (Е)-азометинов - производных 4-аминобензол-сульфамида (стрептоцида), полученных конденсацией замещенных бензальдегидов ванилинового ряда и стрептоцида в среде метанола с выходом 70-82%