Tissue Morphology and Bio-metamaterials as the Driving Mechanism of Electromagnetic Response in the sub THz frequency Range

2012 ◽  
Author(s):  
Paul Ben Ishai ◽  
Eli Safrai ◽  
Alexander Puzenko ◽  
Alexander Polsman ◽  
Yuri Feldman
Keyword(s):  
Electromagnetic Response ◽  
Driving Mechanism ◽  
Frequency Range ◽  
Tissue Morphology

scholarly journals Modelling natural electromagnetic interference in man-made conductors for space weather applications

2016 ◽  
Vol 34 (4) ◽  
pp. 427-436 ◽  
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Exact Solution ◽  
Space Weather ◽  
Electromagnetic Interference ◽  
Geomagnetic Storms ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Variations ◽  
Wide Range

Abstract. Power transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling mis-operation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has a rather complicated structure, simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in space weather applications.

scholarly journals Selective EHF absorber based on BaFe12O19 hexaferrite

2019 ◽  
Vol 30 ◽  
pp. 07006
Author(s):  
Kirill V. Dorozhkin ◽  
Grigorii E. Kuleshov ◽  
Alexander V. Badin ◽  
Maxim O. Gering ◽  
Kseniya V. Simonova
Keyword(s):  
Ferromagnetic Resonance ◽  
Room Temperature ◽  
Hexagonal Ferrite ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Natural Ferromagnetic Resonance

The results of the study of the electromagnetic response of the hexagonal ferrite composite BaFe12O19 in the frequency range 34–250 GHz at room temperature are presented. At a frequency of 46.5 GHz a region of natural ferromagnetic resonance was found. The possibility of creating a selective EHF absorber based on the developed material is shown.

Driveline instability of racing motorcycles in straight braking manoeuvre

2017 ◽  
Vol 232 (17) ◽  
pp. 3045-3061 ◽  
Author(s):  
Luca Leonelli ◽  
Stefano Cattabriga ◽  
Silvio Sorrentino
Keyword(s):  
Time Domain ◽  
Rear Wheel ◽  
Driving Mechanism ◽  
Frequency Range ◽  
Comprehensive Description ◽  
Excited Vibration ◽  
Stability Maps ◽  
Overall Performance ◽  
Road Racing ◽  
Time Invariant

Experimental evidence shows that a self-excited vibration may appear during braking manoeuvres performed by road-racing motorcycles. It involves vertical oscillation of front and rear wheel axles as well as angular oscillation of the driveline in a frequency range between 17 and 22 Hz. As a consequence, severe oscillations of the tyre-ground vertical loads can be observed, leading to a loss of grip and ultimately weakening the vehicle overall performance. Several contributions on this topic can be accounted for in the literature; however, a comprehensive description of the phenomenon has not been given yet. The present work is aimed at simulating the above vibration with a planar multibody motorcycle model, and then at analyzing its driving mechanism. Stability maps are drawn for time-invariant braking manoeuvres, and validated with respect to time domain simulations.

scholarly journals Electromagnetic response from composite carbon-containing structures with technological inhomogeneities at EHF

2021 ◽  
Vol 2140 (1) ◽  
pp. 012010
Author(s):  
E A Trofimov ◽  
G E Kuleshov ◽  
V D Moskalenko ◽  
A V Badin ◽  
K V Dorozhkin
Keyword(s):  
3D Printing ◽  
Transmission Coefficient ◽  
Composite Structures ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Absorption Coefficients ◽  
Polymer Volume ◽  
Composite Carbon ◽  
Frequency Dependences

Abstract The results of studies of the electromagnetic response from composite structures made of a carbon-containing polymer with the inclusion of spherical pores in the bulk of the material and with pyramidal corrugation on the surface of the material are presented. The results of modeling the frequency dependences of the transmission, reflection and absorption coefficients in the EHF range are shown. Samples of composite carbon-containing structures with technological inhomogeneities have been fabricated by 3D printing. Measurements of the electromagnetic response from experimental samples were carried out in the frequency range from 100 to 1000 GHz. At frequencies up to 250 GHz, the inclusion of air pores in the polymer volume reduces the transmission coefficient, practically does not affect the reflection, and increases the absorption. Pyramid corrugated material absorbs more than 99% of radiation in the frequency range from 200 to 635 GHz.

scholarly journals Electromagnetic response from multilayer composite coatings based on carbonyl iron, ferroelectrics and MWCNTs at microwave

2019 ◽  
Vol 30 ◽  
pp. 07011
Author(s):  
Grigoriy E. Kuleshov ◽  
Alexey V. Sbrodov ◽  
Tatyana N. Shematilo
Keyword(s):  
Experimental Study ◽  
Composite Materials ◽  
Carbonyl Iron ◽  
Composite Coatings ◽  
Dielectric Constants ◽  
Electromagnetic Response ◽  
Multilayer Composite ◽  
Frequency Range ◽  
Electromagnetic Characteristics ◽  
Frequency Dependences

The electromagnetic characteristics of composite materials based on carbonyl iron, ferroelectrics, and MWCNTs were studied in this article. The complex magnetic and dielectric constants of the experimental samples were measured in the frequency range from 1 GHz to 18 GHz. The results of calculation and the experimental study of the frequency dependences of the reflection coefficient on a multilayer composite coating located on a reflective surface are presented.

scholarly journals Terahertz Optics of Materials with Spatially Harmonically Distributed Refractive Index

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5208
Author(s):  
Dzmitry Bychanok ◽  
Gleb Gorokhov ◽  
Artyom Plyushch ◽  
Alfredo Ronca ◽  
Marino Lavorgna ◽  
...  
Keyword(s):  
Refractive Index ◽  
Thermoplastic Polyurethane ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Spatially Periodic ◽  
3D Printed ◽  
New Generation ◽  
Analytical Expressions ◽  
Theoretical Results

The electromagnetic properties of structures with spatially periodic distributed graded refractive index were investigated in the terahertz frequency range. The band structure and electromagnetic response of material with harmonically distributed refractive index were calculated and analyzed. The analytical expressions for frequencies of the first and second bandgap are derived. 3D printed gyroid based architectures were proven to be harmonically graded refractive index structures with designed bandgaps in THz frequency ranges. The transmission coefficient of thermoplastic polyurethane-based samples were experimentally measured in the frequency range 100–500 GHz and compared with theoretical results. Due to losses in the real world produced samples, the predicted response is significantly dumped in the terahertz range and only traces of band gaps are experimentally observed. This funding paves the way toward a new generation of 3D printed THz components for gradient-index optics applications.

scholarly journals Broadband selection of EHF radiation of metamaterial surface obtained by photolithography

2021 ◽  
Vol 2140 (1) ◽  
pp. 012012
Author(s):  
K V Bilinskiy ◽  
K V Dorozhkin ◽  
V D Moskalenko ◽  
G E Kuleshov ◽  
A V Badin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Time Domain ◽  
Optical Methods ◽  
Ring Resonators ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Experimental Researches ◽  
Selection Of

Abstract In paper results of research of metamaterial surface based on split-ring resonators obtained by photolithography are presented. Numerical simulation of electromagnetic response of the created structure are shown. Experimental researches of the transmission coefficient using quasi-optical methods of continuous and time-domain spectroscopy in the frequency range from 34 to 200 GHz were carried out. Area of broadband screening in the EHF range has been found.

Density-based discrimination of protein and RNA in the ribosome

1992 ◽  
Vol 50 (1) ◽  
pp. 464-465
Author(s):  
Joachim Frank
Keyword(s):  
Transfer Function ◽  
Spatial Frequency ◽  
Three Dimensional ◽  
Wiener Filter ◽  
Dark Field Image ◽  
Dark Field ◽  
Frequency Range ◽  
Bright Field ◽  
Contrast Transfer Function ◽  
Pass Filter

Cryo-electron microscopy combined with single-particle reconstruction techniques has allowed us to form a three-dimensional image of the Escherichia coli ribosome.In the interior, we observe strong density variations which may be attributed to the difference in scattering density between ribosomal RNA (rRNA) and protein. This identification can only be tentative, and lacks quantitation at this stage, because of the nature of image formation by bright field phase contrast. Apart from limiting the resolution, the contrast transfer function acts as a high-pass filter which produces edge enhancement effects that can explain at least part of the observed variations. As a step toward a more quantitative analysis, it is necessary to correct the transfer function in the low-spatial-frequency range. Unfortunately, it is in that range where Fourier components unrelated to elastic bright-field imaging are found, and a Wiener-filter type restoration would lead to incorrect results. Depending upon the thickness of the ice layer, a varying contribution to the Fourier components in the low-spatial-frequency range originates from an “inelastic dark field” image. The only prospect to obtain quantitatively interpretable images (i.e., which would allow discrimination between rRNA and protein by application of a density threshold set to the average RNA scattering density may therefore lie in the use of energy-filtering microscopes.

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