scholarly journals Detection and estimating the blood accumulation volume of brain hemorrhage in a human anatomical skull using a RF single coil

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10416
Author(s):  
Moshe Oziel ◽  
Boris Rubinsky ◽  
Rafi Korenstein
Keyword(s):  
Experimental Study ◽  
Electromagnetic Radiation ◽  
Hemorrhagic Stroke ◽  
Average Error ◽  
Tissue Fluid ◽  
Brain Hemorrhage ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Single Coil ◽  
Chicken Blood

Objective An experimental study for testing a simple robust algorithm on data derived from an electromagnetic radiation device that can detect small changes in the tissue/fluid ratio in a realistic head configuration. Methods Changes in the scattering parameters (S21) of an inductive coil resulting from injections of chicken blood in the 0–18 ml range into calf brain tissue in a human anatomical skull were measured over a 100–1,000 MHz frequency range. Results An algorithm that combines amplitude and phase results was found to detect changes in the tissue/fluid ratio with 90% accuracy. An algorithm that estimated the injected blood volume was found to have a 1–4 ml average error. This demonstrates the possibility of the inductive coil-based device to possess a practical ability to detect a change in the tissue/fluid ratio in the head. Significance This study is an important step towards the goal of building an inexpensive and safe device that can detect an early brain hemorrhagic stroke.

Gradient structures of Ni – Zn ferrites for electromagnetic radiation protection devices

2021 ◽  
Vol 5 ◽  
pp. 39-46
Author(s):  
V. V. Karanskij ◽  
◽  
S. V. Smirnov ◽  
A. S. Klimov ◽  
E. V. Savruk ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electromagnetic Radiation ◽  
Radiation Protection ◽  
Electromagnetic Compatibility ◽  
Protective Coatings ◽  
Frequency Range ◽  
Near Surface ◽  
Zn Ferrite ◽  
Absorbing Materials ◽  
Plasma Electronic

Increasing the reliability requirements for electromagnetic compatibility of electronic equipment requires the creation of protective coatings that absorb electromagnetic radiation or the development of new radio-absorbing materials. In the frequency range up to 1 GHz, radio-absorbing materials based on Ni – Zn ferrites are of the greatest interest. The absorption of electromagnetic radiation by ferrites occurs due to resonant phenomena at the level of domains and atoms. Improving the performance of ferrites is possible by modifying their surface properties. In this paper, gradient structures for electromagnetic radiation protection products are obtained by treating the surface of Ni – Zn ferrite samples with a low-energy electron beam. To generate the electron beam, a unique development was used — a forevacuum plasma electronic source that allows forming and transporting a beam with a power density of up to 105 W/cm2 under conditions of high pressure and high gas release. As a result of processing, gradient structures were found on the surface of ferrites. A theoretical analysis and experimental study of the obtained structures “non – magnetic conductor – ferrite”, characterized by an increased attenuation coefficient and a reduced reflection coefficient of electromagnetic radiation in the frequency range from 0.5 to 2.5 GHz. The possibility of obtaining near-surface layers depleted in zinc with increased electrical conductivity and reduced magnetic permeability is shown.

scholarly journals Experimental study of particle concentration fluctuations in a turbulent steady flow

2008 ◽  
Vol 49 ◽  
pp. 121-126 ◽  
Author(s):  
François-Xavier Cierco ◽  
Mohamed Naaim ◽  
Florence Naaim-Bouvet
Keyword(s):  
Image Processing ◽  
Experimental Study ◽  
High Speed ◽  
Particle Concentration ◽  
Free Stream ◽  
Frequency Range ◽  
Wind Tunnel Experiments ◽  
Simple Theoretical Model ◽  
Over Time

AbstractSpecific features of the physics of blown sand and PVC particles were investigated in wind-tunnel experiments. The fluctuations in particle concentration over time were derived from image processing of high-speed films (500 Hz). Spectral analysis of these time series showed a slowly decreasing slope within a frequency range that could be larger than the inertial sub-range of the free stream. A specific transport regime also appears in the lower part of the flow for frequencies less than 10 Hz. The role of turbulence in the generation of this regime is discussed using a simple theoretical model able to describe the aerodynamic behavior of a particle.

Electromagnetic fields at work places experts of the cellular companies

10.12737/5019 ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 1-4
Author(s):  
Горохов ◽  
E. Gorokhov ◽  
Ляпкало ◽  
A. Lyapkalo
Keyword(s):  
Magnetic Fields ◽  
Electromagnetic Radiation ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Working Conditions ◽  
Base Stations ◽  
Frequency Range ◽  
Magnetic Components ◽  
Electronic Computers ◽  
The Impact

The paper presents the results of instrumental studies by means of hygienic assessment of levels of electromagnetic fields (EMF) on the workplaces in cellular companies. Measurements of EFM were made on workplaces of 2 groups of employees during the studies: office administrative specialists and technical employees. Instrumental measurements of EMF levels were made by Personal Electronic Computers (PCs) and receivingtransmitting equipment of base cellular stations (BCS). Measurements of EMF from the PC´s screens based on electric and magnetic components were performed: a tension of electric fields with a frequency range of 5Hz-2 kHz and 2 kHz-4 kHz; a tension of magnetic fields in the frequency range of 5Hz-2 kHz and 2 kHz-4 kHz. Measurements of flux density of electromagnetic energy were performed at operating platforms of base stations and at control operating equipment rooms of cellular stations. There were about 150 workplaces of office administrative specialists with PCs surveyed and more 500 workplaces of technical specialists. The activities of administrations of cellular companies were estimated to ensure the safety of working conditions of employees under the influence of electromagnetic radiation (EMR). Literature data on the impact of EMR on human health and health of employees were presented.

Sign in / Sign up

Export Citation Format

Share Document