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Karaseva N.A.,Lipetsk State Technical University | Ermolaeva T.N.,Lipetsk State Technical University
Talanta | Year: 2014

Piezoelectric immunosensors on the basis of homologous and group-specificantibodies have been developed for detecting penicillin G, ampicillin, and the total content of penicillin antibiotics. The receptor coating of the sensor was obtained by the immobilization of penicillin G or ampicillin hapten-protein conjugates on the polypyrrole film obtained by electropolymerization and activated by glutaraldehyde. The affinity constants and the cross reactivity coefficients have been calculated. This made it possible to estimate the affinity and specificity of the polyclonal and monoclonal antibodies used. The calibration curves are linear in the range of concentrations 2.5-250.0 ng ml-1 (penicillin G), 2.5-500.0 ng ml -1 (ampicillin), and 1-500 ng ml-1 (group of penicillin). The limits of detection are 0.8 ng ml-1, 3.9 ng ml-1, which are lower than MRL, established for penicillin antibiotics. The sensors were tested in detecting penicillins in milk, pork, beef, liver. © 2013 Elsevier B.V.

Karaseva N.,Lipetsk State Technical University | Ermolaeva T.,Lipetsk State Technical University
Microchimica Acta | Year: 2015

Piezoelectric immunosensors have been developed for the determination of trace concentrations of Staphylococcal enterotoxin A (SEA) in foodstuff. Antibodies against SEA were covalently immobilized on an electropolymerized polypyrrole substrate on a gold electrode which warrants increased stability of the biolayer and sensitive detection. The calibration plot is linear in the 1–80 ng∙mL‾1 SEA concentration range, the limit of detection is 0.4 ng∙mL‾1, and the time of analysis is <30 min. The sensor was successfully applied to quantify SEA in chicken meat and milk. [Figure not available: see fulltext.] © 2015, Springer-Verlag Wien.

Cherkashina T.I.,Lipetsk State Technical University | Mazur I.P.,Lipetsk State Technical University | Aksenov S.A.,National Research University Higher School of Economics
Materials Science Forum | Year: 2013

Numerical and physical simulation on model samples can provide data for various aspects of metal forming, without resorting to time-consuming and costly full-scale tests. This paper presents examples of modeling of the deformation of a slab with a liquid core. The use of soft reduction can enhance the homogeneity of the structure, which improves the quality of cast billets. Mathematical modeling is described here where the fluid layer is taken into account by the influence of boundary conditions in the crust in the form of ferrostatic pressure, which allows calculation of the intensity of deformation, total deformation and strain. It also provides a novel method for studying the process of soft reduction. It is based on a physical model of the slab consisting of a closed solid shell made of a calibrated lead shot and the Wood's alloy. To simulate the liquid molten metal, the interior of the shell is filled with gelatin. This approach can be applied to further studies on deformation processes and the penetration of deformation into complex metallic systems. © (2013) Trans Tech Publications, Switzerland.

Schmidt A.,Lipetsk State Technical University
Materials and Manufacturing Processes | Year: 2011

Genetic algorithm is an emerging technique used in engineering design activities to find an optimized solution which satisfy a number of design goals. Nonlinear direct method of goal search use successive linearization techniques, which are sensitive to the chosen starting solution and quality of the objective function. The proposed technique can solve programming problems having non-convex regions, which are usually avoided in classical optimization problems. The efficacy of the proposed novel method is demonstrated by solving a number of test problems. The results suggest that the proposed method is effective and represents a practical tool for solving sheet forming problems. Copyright © Taylor & Francis Group, LLC.

Babkin A.S.,Lipetsk State Technical University | Gladkov E.A.,Moscow State Technical University
Welding Journal | Year: 2016

This paper presents a new graphical method for determining welding parameters of qualitative welds in gas metal arc welding (GMAW). The mathematical models of quality criteria for GMAW of mild and low-alloy steels in the flat position are described. It was proposed to use the weld sizes, such as depth of penetration, bead width, and reinforcement, as quality criteria. By means of mathematical statistics, one has shown that for the given random variations of the welding parameters, the proposed mathematical models allow calculation of the weld sizes with acceptable accuracy. A technique for constructing an optimal welding parameter area was proposed. Such optimal process provides high-quality weld formation of square and double square-groove welds.

Karaseva N.A.,Lipetsk State Technical University | Ermolaeva T.N.,Lipetsk State Technical University
Talanta | Year: 2012

A piezoelectric immunosensor on the basis of electrogenerated polymer for detecting trace quantities of chloramphenicol, a drug which is used in veterinary for treatment and prevention of infectious diseases, was developed. The detection was conducted in a competitive format with the use of hapten-protein conjugate and monoclonal antibodies. The limit of detection is 0.2 ng ml -1, the calibration curve is linear in the range of concentrations 0.5-100.0 ng ml -1. Chloramphenicol was detected in food (meat, milk, egg, honey). © 2011 Elsevier B.V. All rights reserved.

Mikhaylov V.V.,Lipetsk State Technical University | Chesnokov A.V.,Lipetsk State Technical University
Proceedings of the 7th International Conference on Textile Composites and Inflatable Structures, STRUCTURAL MEMBRANES 2015 | Year: 2015

Pneumatic air-inflated cushions are considered. The iteration technique for obtaining equilibrium pressure in their chambers is offered. It is based on the Broyden's method and uses the proposed function of cushion's surface and the differential equation of equilibrium. The technique for obtaining the maximum load, which may be applied on a cushion, is proposed. The research of the influence of temperature variations on the behavior of pneumatic cushions is executed.

Chesnokov A.V.,Lipetsk State Technical University | Mikhaylov V.V.,Lipetsk State Technical University
Proceedings of the 7th International Conference on Textile Composites and Inflatable Structures, STRUCTURAL MEMBRANES 2015 | Year: 2015

Rectangular pneumatic envelopes, made of a polymer film, are considered. The envelopes are subjected to non-uniform external loads, which consist of symmetric and inverse-symmetric parts. The functional dependence describing the envelope's surface is given. The improved technique for obtaining geometrical parameters of envelopes is offered. It uses the differential equation of equilibrium, the method of least squares and the linearization procedure with Taylor series. The results of the work may be used for taking into account physical non-linear properties of polymer membranes, for estimation of changes of air-pressure in pneumatic cushions, for selection the most appropriate embodiment of the cushion from a set of possible variants.

Blyumin S.L.,Lipetsk State Technical University
Automation and Remote Control | Year: 2011

In the paper, we discuss a role of quantum calculus, "differential calculus without taking limits" as a discrete analog of continuous mathematical analysis oriented on information technologies. We studied distinctive calculi that are alternative to quantum calculus and relate finite discriminators of values of an argument with finite discriminators of values of a function at their different combinations. © Pleiades Publishing, Ltd., 2011.

Schmidt A.,Lipetsk State Technical University
Procedia Computer Science | Year: 2012

The analysis at nano-scale is important for the modeling of plastic deformation and its structures. We reviewed algorithms at nano-scale using FEM and presented a solution for modeling of such processes and corresponding algorithms. Also, we studied dislocations and avalanches in the deformed body, how they affect the quality, and methods to decrease their affluence on the product. For meshing of the model proposed method is to relate particle size and mechanical properties, which is investigated in the context of plastic deformation. Damage models presented in the paper can be proved useful for the production modeling and manufacturing. Modeling of buckling and plastic deformation proved to be useful to study the phenomenon and can be optimized with the proposed methods. Numerical verification using test benchmarks were conducted to demonstrate flange buckling, its particle measurements, and avalanches in the deformed part to validate propositions. © 2012 Published by Elsevier Ltd.

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