Samara State Technical University | Date: 2017-03-22
The invention relates to a method for compensating aberrations of an active optical system by a deformable mirror (1), comprising:(a) formation of a matrix N, binding the optical system aberrations with the displacements of the surface of a deformable mirror (1), presented as a superposition of natural frequency modes of a mirror simulator (3) having the same geometric shape and the same elasticity characteristics as the deformable mirror (1) but having zero density except for concentrated masses attached at points corresponding to the places of action of force actuators (4) onto the deformable mirror (1);(b) formation of a matrix M, binding the coefficients of the natural frequency modes of the mirror simulator (3) with the forces or displacements of the force actuators (4) that deform the mirror (1);(c) generation of a matrix F of forces or displacements for loading the deformable mirror (1) on the basis of the aberration measurement, using the matrices N and M.
Samara State Technical University | Date: 2016-09-15
Somov S.,Samara State Technical University
AIP Conference Proceedings | Year: 2017
We consider an information satellite which may be placed on an orbit with altitude from 600 up to 1000 km. We study problems on control of eight electro-reaction engines for a station-keeping of a land-survey satellite on sun-synchronous orbit. © 2017 Author(s).
Pashchenko D.,Samara State Technical University
International Journal of Hydrogen Energy | Year: 2017
The thermochemical waste-heat recuperation is one for perspective way of increasing the energy efficiency of the fuel-consuming equipment. In this paper, the thermochemical waste-heat recuperation (TCR) by combined steam-dry propane reforming is described. To understand the influence of technological parameter such as temperature and composition of inlet gas mixture on TCR efficiency, thermodynamic equilibrium analysis of combined steam-dry propane reforming was investigated by Gibbs free energy minimization method upon a wide range of temperature (600-1200 K) and different feed compositions at atmospheric pressure. The carbon and methane formation was also calculated and shown. From a thermodynamic perspective, the TCR can be used for increasing energy efficiency at temperatures above 950 K because in this range the maximum conversion rate is reached (from 1.22 to 1.30 for the different feed composition). Approximately 10 mol of synthesis gas can be generated per mole of propane at the temperatures greater than 1000 K. Furthermore, the propane conversion rate and yield of hydrogen are increased with the addition of extra steam to the feed stock. Also, undesirable carbon formation can be eliminated by adding steam to the feed. The thermodynamic equilibrium analysis was accomplished by IVTANTHERMO which is a process simulator for thermodynamic modeling of complex chemically reacting systems and several results were checked by Aspen-HYSYS. © 2017 Hydrogen Energy Publications LLC.
Volokitin A.I.,Jülich Research Center |
Volokitin A.I.,Samara State Technical University |
Persson B.N.J.,Jülich Research Center
Physical Review Letters | Year: 2011
We investigate the van der Waals friction between graphene and an amorphous SiO2 substrate. We find that due to this friction the electric current is saturated at a high electric field, in agreement with experiment. The saturation current depends weakly on the temperature, which we attribute to the quantum friction between the graphene carriers and the substrate optical phonons. We calculate also the frictional drag between two graphene sheets caused by van der Waals friction, and find that this drag can induce a voltage high enough to be easily measured experimentally. © 2011 American Physical Society.
Enikeev R.,Samara State Technical University
Food Chemistry | Year: 2012
An easy-to-use method for quantitative analysis of bacterial exopolysaccharides (EPS) was developed. The acid treatment was resultant in removing proteins and lactose and allowed to avoid long-term operation as dialysis. It was shown that, as opposed to anthron and phenol-sulphuric acid methods, reducing sugars method after EPS hydrolysis with glucose as standard provided reliable results, no matter to the EPS monosaccharide composition. EPS quantity in kefir of different brands was varied greatly, approximately at 50-200 mg/l, showing potential to enhance kefiran production by alteration of technological process. The temperature optimum for EPS production by kefir grains and kefir starter was about 30 °C, while the rise of temperature increased soluble EPS in culturing media by means of extraction from kefir grain body. © 2012 Elsevier Ltd. All rights reserved.
Saifutdinov B.R.,Samara State Technical University
Russian Journal of Physical Chemistry A | Year: 2013
The relationships that associate the equilibrium distribution constant and retention factor in high-performance liquid chromatography are analyzed critically. The K c = kV M/v a + 1 relationship suggested by Yu.A. El'tekov is derived without using the relationship between the Henry adsorption constant and the retention factor. The incorrectness of using another relationship, K c = k/φ, to calculate the distribution constant, which is determined by ignoring the excess character of the retention factor measured experimentally when deriving it, is demonstrated. It is proposed that the retention factor be determined by the ratio of the excess amount of adsorbate in an adsorption layer to the amount of adsorbate in bulk solution. © 2013 Pleiades Publishing, Ltd.
Rapoport E.Ya.,Samara State Technical University
Journal of Computer and Systems Sciences International | Year: 2013
The minimization problem for deviations of the stationary state of a system with distributed parameters from a desired state estimated in the uniform metric is considered. A constructive method for its solution using a successive parameterization of controls and the alternance properties of optimal spatial distributions of the controlled variable is proposed. Examples of the use of the proposed computational scheme of the organization of computational algorithms in optimization problems of stationary thermal conductivity processes are discussed. © 2013 Pleiades Publishing, Ltd.
Shiryaev A.K.,Samara State Technical University
Current Organic Chemistry | Year: 2012
This review is devoted to the design of new salen type ligands and its applications in the asymmetric catalysis. The main achievements in this field include development of recyclable catalysts, investigation of the mechanism of the secondary alcohols oxidative resolution and the asymmetric Henry reaction, and a study of the synthetic advantages of the salen complex catalysis. The aim of this review is to present an overview of the literature on the recent progress in the salen ligand catalytic chemistry. © 2012 Bentham Science Publishers.
Somov S.,Samara State Technical University
AIP Conference Proceedings | Year: 2012
Problems of nonlinear modeling, dynamic analysis and simulation of spatial motion by a spacecraft with a flexible weak damping structure, are considered. Attitude motion of a flexible spacecraft with pulse-width control, spin-up rotors of six single-gimbal control moment gyros (CMGs) at the initial, service and emergency modes, is studied. Results on analysis of the spacecraft nutation and flexible oscillations, are represented. © 2012 American Institute of Physics.