On the Definition of Effective Permittivity and Permeability For Thin Composite Layers

The problem of definition of effective material parameters (permittivity and permeability) for composite layers containing only one-two parallel arrays of complex-shaped inclusions is discussed. Such structures are of high importance for the design of novel metamaterials, where the realizable layers quite often have only one or two layers of particles across the sample thickness. Effective parameters which describe the averaged induced polarizations are introduced. As an explicit example, we develop an analytical model suitable for calculation of the effective material parameters $\epsilon_{\rm{eff}}$ and $\mu_{\rm{eff}}$ for double arrays of electrically small electrically polarizable scatterers. Electric and magnetic dipole moments induced in the structure and the corresponding reflection and transmission coefficients are calculated using the local field approach for the normal plane-wave incidence, and effective parameters are introduced through the averaged fields and polarizations. In the absence of losses both material parameters are purely real and satisfy the Kramers-Kronig relations and the second law of thermodynamics. We compare the analytical results to the simulated and experimental results available in the literature. The physical meaning of the introduced parameters is discussed in detail.Comment: 6 pages, 5 figure

Micro turbinas de gas con generadores de alta velocidad para sistemas de energia locales inteligentes

At present, the share of energy collected from renewable resources and low-power units is growing, and the generation becomes distributed, having many facilities that operate in co-generation mode. That is why the construction of an energy system with distributed heterogeneous sources and the improvement of its efficiency have become widely discussed issues. This paper proposes a solution of a local smart energy systemfortheTechnoEcoPark, a sciencepark of Rostov State Transport University, Rostov, Russia. The solution aims to integrate the distributed generation facilities, including environmentally friendly renewable resources, grid infrastructure and consumers with controllable and uncontrollable load. Theapproachtothe problem is the application of a smart control systemthatmanagesgeneration, distribution and consumptionof energy in a mini-CHP-based autonomous energy system. Such smart control systems reveal the trends of optimal energydistribution in a autonomousenergysystem. The study substantiates that installation of an in-house mini-CHP can solve the task of supplying heat and powertotheTechnoEcoPark. The important advantage of the solution is a significant reduction of expenses on energy consumption as the generation costs less compared to the grid tariffs. The proposed energy supply system of the TechnoEcoPark exemplifies the integration of heterogeneous heat and power sources and consumers into a commonnetwork. The paper outlines the mechanisms of the energy system efficiency improvement. These mechanisms make it possible to provide heat and power supply services to consumers and to return the generated power into the centralized grid. The materials of the paper can be of use to the specialists and researchers who are interested in generation and distribution of energy in autonomous systems.En la actualidad, la proporción de energía recolectada de recursos renovables y unidades de baja potencia está creciendo, y la generación se distribuye, teniendo muchas instalaciones que operan en modo de cogeneración. Es por eso que la construcción de un sistema de energía con fuentes heterogéneas distribuidas y la mejora de su eficiencia se han convertido en temas ampliamente discutidos. Este documento propone una solución de un sistema de energía inteligente local para TechnoEcoPark, un parque científico de la Universidad Estatal de Transporte de Rostov, Rostov, Rusia. La solución tiene como objetivo integrar las instalaciones de generación distribuida, incluidos los recursos renovables ecológicos, la infraestructura de la red y los consumidores con carga controlable e incontrolable. El enfoque del problema es la aplicación de un sistema de control inteligente que gestiona la generación, distribución y consumo de energía en un sistema de energía autónomo basado en mini-CHP. Tales sistemas de control inteligente revelan las tendencias de distribución óptima de energía en un sistema energético autónomo. El estudio confirma que la instalación de un mini-CHP interno puede resolver la tarea de suministrar calor y energía al TechnoEcoPark. La ventaja importante de la solución es una reducción significativa de los gastos en consumo de energía, ya que la generación cuesta menos en comparación con las tarifas de la red. El sistema de suministro de energía propuesto por TechnoEcoPark ejemplifica la integración de fuentes heterogéneas de calor y energía y consumidores en una red común. El documento describe los mecanismos de mejora de la eficiencia del sistema energético. Estos mecanismos permiten proporcionar servicios de suministro de calor y energía a los consumidores y devolver la energía generada a la red centralizada. Los materiales del documento pueden ser de utilidad para los especialistas e investigadores interesados ​​en la generación y distribución de energía en sistemas autónomos