Структурное моделирование метаматериалов
This paper presents a computer model of a FSS based on mushroom-shaped metamaterial. The model is based on the calculation of equivalent distributed inductance and distributed capacitance of the unit cell of the surface according to its geometric dimensions. The computer model is realized as the “META” program based on MathCAD ver.15 software and provides an opportunity to investigate the dispersion characteristics of the frequency-selective surface of a “Maltese cross” mushroom-shaped metamaterial.
The results of the study of radiation-induced strengthening and microstructure evolution in the 0Kh18N10T austenitic stainless steel irradiated by neon ions (with energy of 230 MeV) and neutrons (En > 0.1 MeV) are presented. The experiments were performed in an inner beam of an U-400 cyclotron in Dubna and in an EWA reactor (Institute of Atomic Energy, Swerk, Poland). The dependence of the mechanical properties on the dose of irradiation-induced damage was determined. Changes in microstructure are studied by TEM, and the density of the aggregates of irradiation-induced defects was determined as a function of the dose. The data obtained are discussed in terms of mechanical properties and microstructure characteristics.
In this paper, an overview of slow wave systems and metamaterials using in devices intended for application in the area of biomedical engineering is presented. Short characteristic of physical and engineering specifications of slow waves systems and metamaterials are listed. In addition, possible variants of upgrading an exciting engineering solution by dint of slow wave systems and metamaterials application are offered.
The conference is co-organized by the Foundation for Research and Technology – Hellas (FORTH), one of the biggest and most successful research centres in Greece, and in particular by its Institute of Electronic Structure and Laser (IESL), which is an internationally recognized center of excellence in Lasers and Applications, Microelectronics and Devices, Materials Science and Theoretical and Computational Physics. Besides FORTH, Crete has other Institutions, with more recognized the University of Crete, centered at Heraklion, which was classified among the top 100 young (less than 50 years old) Universities worldwide, as well as the Technical University of Crete, located in Chania, with emphasis in Engineering Sciences. All these institutions are characterized by high quality research and education, making Crete a place that combines a glorious past with an inspiring present.
Reasons of appearance and possible ways of frequency dispersion control in metamaterials based on helix structures with the help of a longitudinal propagation ground plane and a ground plane with capacitive conductivity in azimuth direction are considered. It is shown that existence of metamaterial constructions based on helix systems with abnormal dispersion is a perspective way of reduction if devices longitudinal dimensions keeping the same time their electrodynamics characteristics and parameters. In the case with frequency rise up the wave phase velocity also increases keeping the structure electrical length and the presence of slow-wave coefficient allows structure dimensions decreasing.
The paper deals with the algorithm of the identification of discrete systems with variable delay, consisting of an ideal sampler, zero-order hold and the linear continuous part. The delay parameter (fractional part of time delay) is estimated through the inverse modified Z-transform. The estimation is based on the equality of the continuous-time part step response to zero at the time delay point. The time delay of the discrete system (integer component) is adjusted by means of the integer part of the estimate obtained.
The 18th International Vacuum Electronics Conference (IVEC 2017) helded on 24-26 April 2017 in London, UK. With technical co-sponsorship from the IEEE Electron Devices Society (EDS), the conference provide a forum for scientists and engineers from around the globe to present the latest developments in vacuum electronics technology at frequencies ranging from the UHF to THz frequency bands. IVEC was originally created in 2000 by merging the U.S. Power Tubes Conferences and the European Space Agency TWTA Workshops. Now a fully international conference, IVEC is held every other year in the U.S., and in Europe and Asia alternately every fourth year.
The papers appearing in this book comprise part of the proceedings of the 13th International Congress on Artificial Materials for Novel Wave Phenomena – Metamaterials 2019. All papers have been independently peer reviewed before final submission to the conference. They reflect the authors’ opinions and, in the interests of timely dissemination, are published as presented and without change. Their inclusion in this publication does not necessarily constitute endorsement by the editors or the Metamorphose VI AISBL.
A method based on the spectral analysis of thermowave oscillations formed under the effect of radiation of lasers operated in a periodic pulsed mode is developed for investigating the state of the interface of multilayered systems. The method is based on high sensitivity of the shape of the oscillating component of the pyrometric signal to adhesion characteristics of the phase interface. The shape of the signal is quantitatively estimated using the correlation coefficient (for a film–interface system) and the transfer function (for multilayered specimens).
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.