Scintillation effects in the magnetized plasma

Statistical characteristics of scattered electromagnetic waves in the turbulent magnetized plasma caused by electron density fluctuations are calculated using complex geometrical optics approximation taking into account both diffraction effects and polarization coefficients. Scintillation level normalized on the variance of the phase fluctuations is analyzed analytically and numerically for small-scale plasma irregularities using the experimental data. New properties of the electromagnetic wave scintillations have been revealed. It is shown that splashes arise in the ionosphere leading to the turbulence and generation of new oscillations (waves and/or Pc pulsations) propagating in space and the terrestrial atmosphere. Turbulence extending in the lower atmospheric layers can influence on the meteorological parameters leading to climate change.Web of Science8116515

Design of plasmonic-waveguiding structures for sensor applications

Surface plasmon resonance has become a widely accepted optical technique for studying biological and chemical interactions. Among others, detecting small changes in analyte concentration in complex solutions remains challenging, e.g., because of the need of distinguishing the interaction of interest from other effects. In our model study, the resolution ability of plasmonic sensing element was enhanced by two ways. Besides an implementation of metal-insulator-metal (MIM) plasmonic nanostructure, we suggest concatenation with waveguiding substructure to achieve mutual coupling of surface plasmon polariton (SPP) with an optical waveguiding mode. The dependence of coupling conditions on the multilayer parameters was analyzed to obtain optimal field intensity enhancement.Web of Science99art. no. 122

Homogeneous magnetic field source for attenuated total reflection

The paper is focused on the study of two-dimensional magnetic field distribution used for an analysis of samples containing magnetically active films by means of the Attenuated Total Reflection (ATR) method. The design of a proposed electromagnet and the magnetic field model computation are presented together with the results obtained from magnetic field distribution measurement. The ATR method can provide information about a thin film thickness, refractive index, and attenuation in addition to the perfunctory coupling of an optical wave into and off a waveguide [1, 2]. The prism coupling conditions are determined for magnetic structures with induced anisotropy. The prism – a film coupler is located in the central cavity of a magnetic yoke. By current switching in the coils, we can change the amplitude and magnetic field direction in order to modulate the induced anisotropy in a thin film with magnetic ordering. By the in-plane modulation of the magnetization direction in the samples, we can change the rotation and elasticity of outgoing light

Intensity distribution of strong magnetic fields created by opposing linear Halbach assemblies of permanent magnets

The work is devoted to the geometrical configuration of permanent magnets on the basis of opposing geometrically linear assemblies (e.g. Halbach arrays) for the generation of strong magnetic fields, which have been theoretically modeled and experimentally verified. The implementation of these opposing assemblies using NdFeB magnets of a total weight of 3.75 kg provided a value of magnetic induction in the middle of an air gap of a width of 20 mm that was higher by 56% in comparison with the simplest possible design. When the air gap width was 3 mm, the induction reached a value of 2.16 T, which represents an increase of more than 100%. Simultaneously, however, unlike in the simplest possible parallel configuration, opposing Halbach assemblies have shown, in the middle of an air gap, a significant decrease of the magnetic induction values when passing from the middle of the assemblies in the direction parallel to the x-axis.Web of Science34512

The determination of cystatin C in biological samples via the surface plasmon resonance method

Surface plasmon resonance imaging biosensors have a number of advantages that make them superior to other analytical methods. These include the possibility of label-free detection, speed and high sensitivity to low protein concentrations. The aim of this study was to create and analyze biochips, with the help of which it is possible to test cystatin C in patient urine samples and compare the results with the one-time traditional ELISA method. The main advantage of the surface plasmon resonance imaging method is the possibility of repeated measurements over a long period of time in accordance with clinical practice. The surface of the biochip was spotted with anticystatin C and a negative control of mouse IgG at a ratio of 1:1. The aforementioned biochip was first verified using standard tests and then with patient samples, which clearly confirmed the required sensitivity even for very low concentrations of cystatin C. METHOD SUMMARY Surface plasmon resonance is a sensitive optical method that uses the generation of electromagnetic waves (plasmons) for detection. The propagation of surface plasmons at the metal-dielectric interface is very sensitive to changes in the refractive index, which allows for the monitoring of substance properties very close to the interface. The main advantage of the sensor over other currently used techniques is the possibility of label-free analysis and real-time analysis, with high sensitivity and specificity of the optical method.Nanotechnology Centre, VSB - Technical University of Ostrava [SGS SP 2020/20

Automatizované systémy řízení a magnetická defektoskopie ocelových lan

Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta strojn

Procesy digitalizace a filtrace výstupních signálů z magnetických defektoskopů ocelových lan

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta hornicko-geologick

Programové vybavení měřícího mikropočítačového systému ve zkušebně lan VVUÚ Radvanice

Prezenční352 - Katedra automatizační techniky a řízeníNeuveden

Magnetic field source for dark mode spectroscopy

The paper is focused on the study of two-dimensional magnetic field distribution used for the analysis of the samples containing magnetically active films by means of dark mode spectroscopy (DMS). The design of proposed electromagnet for in-plane magneto-optic configuration and the magnetic field model computation are presented together with the results obtained from magnetic field distribution measurement

Surface plasmon resonance sensor with a magneto-optical structure

Due to resonant excitation of surface plasmons, surface plasmon resonance (SPR) sensors combined with ferromagnetic thin films allow an enhancement of the magneto-optical (MO) response. MO-SPR structures with Au/Co/Au sandwiches are theoretically analyzed in transverse configuration by 4×4 matrix algebra. The influence of sandwich film thickness, layer order and Co–Au multilayers on the relative change of the reflectance for p-polarized waves is analyzed. The results show the important role of the incidence angle distribution of the reflectance without magnetic ordering on the MO-SPR response. An optimized geometry and a corresponding feedback are discussed