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Rybin O.,Kharkiv State University of Food Technology and Trade | Raza M.,Bahauddin Zakariya University
International Journal of Applied Electromagnetics and Mechanics | Year: 2010

Analytical and numerical optimization method for evaluating the complex effective dielectric and magnetic constants of elementary flat slab of metamaterial is presented. The minimization problem is solved for a cascaded network representation of the slab utilizing the Effective Medium Theory. The algorithm is benchmarked using the free Meep FDTD software package. © 2010 - IOS Press and the authors. All rights reserved.


Rybin O.N.,Kharkiv State University of Food Technology and Trade | Pitafi A.I.,Bahauddin Zakariya University
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2011

An analytical modeling and numerical analysis of the effective electromagnetic response of two-component metamaterial medium with spherical metallic inclusions is presented. Calculationshave been made within the microwave frequency range. The analytical modeling has been done using two different modified mathematical models of the complex relative permittivity and permeability for unbounded composite medium with spherical inclusions. Numericalsimulations of the above mentioned parameters have been made using S-parameters obtained from Finite-Difference Time-Domain technique. The numerical simulation has been carried out for different radii of the inclusions. Remarkable coincidence between analytical and numericalresults was found. The enhancement of effective relative permittivity and refractive index of the considered composite has been observed. Recommendations for the practical application of presented artificial material for designing microwave patch antennas have shortly beendiscussed. © 2011 by Begell House, Inc.


Rybin O.,Kharkiv State University of Food Technology and Trade | Rybin O.,Kharkov National Academy of Municipal economics
International Journal of Applied Electromagnetics and Mechanics | Year: 2012

In the paper, the possibility of achieving negative permeability for two-component metamaterials is analytically proven. The metamaterial media are presented as an infinite host dielectric material (air) with periodically embedded ferric cylindrical and spherical inclusions saturated with a biasing external magnetic field. The appropriate frequency-dependent inequalities are obtained in the frequency range where permeability becomes negative. The cases when electromagnetic wave propagates parallel and transverse to the direction of biasing magnetic field are studied. © 2012 - IOS Press and the authors. All rights reserved.


Rybin O.,Kharkiv State University of Food Technology and Trade
International Journal of Applied Electromagnetics and Mechanics | Year: 2012

The complex effective relative permeability of a two-component ferrite-like metamaterial was studied for the two cases of electromagnetic wave propagation with respect to direction of dc magnetic bias field, namely, parallel and transverse. The metamaterial of interest is the host dielectric with periodically embedded ferric cylindrical or spherical inclusions. The inclusions are saturated with the biasing magnetic field and the magnetic losses are taken into account. The analysis was performed utilizing the Microwave Effective Medium Theory for two-component artificial composite materials with saturated lossless ferric inclusions [1]. Computations revealed that low values of refractive index as well as negative values of permeability can be achieved. © 2012-IOS Press and the authors. All rights reserved.


Zolochevsky A.,Kharkiv Polytechnic Institute | Parkhomenko L.,Kharkiv State University of Food Technology and Trade | Kuhhorn A.,TU Brandenburg
Materials Chemistry and Physics | Year: 2012

The effects of oxygen exchange kinetics at the oxygen-lean side of the perovskite-type hollow fiber membrane for oxygen separation from air, on chemical stresses, as well as those from bulk oxygen transport, are studied. Closed-form analytical solutions for oxygen permeation flux at steady state in the fiber lumen, and for the distribution of oxygen non-stoichiometry and chemical stresses in a transient state in the hollow fiber membrane have been obtained. Different operating modes of the Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ hollow fiber membrane module to produce oxygen from air at 1173 K have been considered including sweep-gas operation, high-pressure operation and vacuum operation. Values of the chemical surface exchange coefficient in the broad range of oxygen partial pressure and the chemical diffusion coefficient have been determined from the permeation measurements. Values of the oxygen non-stoichiometry on both sides of the Ba 0.5Sr 0.5Co 0.8Fe 0.2O 3-δ hollow fiber at equilibrium with the surrounded atmosphere have been obtained from the experimental data for different operating modes of membrane module. Chemical stresses in the hollow fibers of the module with three operating modes have been calculated. Practical recommendations on how to improve the performance and operating conditions, as well as, to avoid membrane break have been formulated. Investigations have shown that influence of oxygen surface exchange kinetics on chemical stresses increases strongly with decreasing the hollow fiber membrane thickness. © 2012 Elsevier B.V. All rights reserved.


Zolochevsky A.,Kharkiv Polytechnic Institute | Grabovskiy A.V.,Kharkiv Polytechnic Institute | Parkhomenko L.,Kharkiv State University of Food Technology and Trade | Lin Y.S.,Arizona State University
Solid State Ionics | Year: 2012

The durability of the perovskite-type ceramic oxygen ion-conducted membranes strongly depends on the magnitude of the chemically induced stresses. This paper examines the influence of both membrane thickness and exchange of oxygen vacancies at the interface between the membrane surface and surrounding gas phase on the chemically induced stresses in the tubular perovskite-type membrane under the gradient of oxygen partial pressure created between air and an inert gas. A mathematical model relating the chemically induced strains and stresses in the tubular membrane to oxygen non-stoichiometry in perovskite-type oxide has been developed, and solved numerically by the ANSYS codes. Calculation results show that when the membrane thickness is significantly higher than the so-called characteristic membrane thickness, the largest first principal stress on the air feeding side of the membrane is practically identical to the one found under the assumption of the constant oxygen non-stoichiometry condition on the permeate side. An analogous comparison for the largest von Mises stress on the permeate side of the membrane gives rise to the difference by 50%. The influence of the oxygen surface exchange kinetics on the stresses strongly increases with decreasing thickness of the membrane. In case of the membrane of 0.1 mm thickness which is of the same order of magnitude as the characteristic membrane thickness, the largest first principal stress on the feeding side that was calculated without and with oxygen surface exchange effect is different by a factor of two, while the corresponding largest von Mises stresses on the permeate side are different by a factor of about four. In general, the presence of oxygen surface exchange resistance and reduced membrane thickness lower the chemically induced stresses. © 2012 Elsevier B.V. All rights reserved.


Rybin O.,Kharkiv State University of Food Technology and Trade
International Journal of Applied Electromagnetics and Mechanics | Year: 2011

In this paper, Effective Medium Theory for two-component metamaterial media as infinite host dielectric medium embedded periodically with cylindrical iron inclusions and spherical ones saturated with an external biasing magnetic field is developed in the microwave frequencies. The long wave approximation of effective permeability tensors for the considered metamaterial media has been obtained using the microwave extension of Effective Medium Approximation for polycrystalline ferrites and the long wave approximation of expressions of the effective magnetic permeability for two-component undiluted metal-dielectric composites with infinitely long non-magnetic metal cylindrical and spherical inclusions. The effective magnetic properties of the metamaterial media for the case of microwave propagation transverse to bias have been studied. It is shown that the considered metamaterial can exhibit the ultra-low refractive index phenomenon and the phenomenon of negative magnetic permeability for the case of microwave propagation transverse to bias. © 2011 ? IOS Press and the authors.


Rybin O.,Kharkiv State University of Food Technology and Trade
International Conference on Mathematical Methods in Electromagnetic Theory, MMET | Year: 2012

Alternative numerical optimization technique for evaluating the complex effective relative permittivity and permeability of elementary sub-slab with the thickness equals the constant of unit cell of a slab metamaterial is presented. The technique is benchmarked with the help of free FDTD software and the optimization technique obtained previously in [1]. © 2012 IEEE.


Ziolkovska A.,Kharkiv State University of Food Technology and Trade
Food Hydrocolloids | Year: 2012

This study examined the application of few-stages aqueous extraction of mucilage from whole flaxseed. Key processing conditions included temperature (40-100 °C), duration (0-60. min), seed to water ratio (1 to 5-30) and mixer rotational speed (0-240 revolutions per minute). It was found, that mucilage extraction from flaxseed is appropriate to carry out without swelling. The maximum yield of flaxseed mucilage was obtained at 80 ± 2 °C with seed to water ratio of 1 to 25. The equation, which described equilibrium solid yield during the extraction depending on the phases' ratio and the temperature, was found. The equation of solid yield depending on duration and mixer rotational speed under the temperature of 80 ± 2 °C and the seed to water ratio of 1 to 25 was determined. It was showed, that the use of stirring is not expedient for the intensifying the process. The rational duration of extraction under the selected parameters was 30 ± 1. min. To increase the solid content in the extract the few-stages extraction was applied. The three-stage countercurrent extraction of flaxseed mucilage from whole seeds under the temperature of 80 ± 2 °C, the seed to water ratio of 1 to 25, the duration of each stage of 30 ± 1. min was established to receive flaxseed mucilage extract with content of solids from 0.70 to 0.72%, i.e. to extract from 98.3 to 99.1% of mucilage from flaxseed. © 2011 Elsevier Ltd.


Rybin O.,Kharkiv State University of Food Technology and Trade
International Journal of Modern Physics C | Year: 2013

A new optimization technique for evaluating the complex effective relative permittivity and permeability of elementary sub-slab whose thickness equals to the constant of a unit cell of a slab metamaterial is developed. The objective of the technique is based on a numerical solving of appropriate minimization problem for a cascaded network representation of the slab metamaterial utilizing the Effective Medium Theory (EMT) and the definition of S- and T-parameters of the metamaterials considered as a four-pole network. The technique is tested using the open source FDTD software package and the optimization technique obtained [O. Rybin and M. Raza, Int. J. Appl. Electrom. Mech. 32, 207 (2010)]. © 2013 World Scientific Publishing Company.

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