Sources Of Electromagnetic Radiation Research Articles

Lens-free digital holographic microscopy for cell imaging and tracking by Fresnel diffraction from a phase discontinuity

In this Letter, a very simple, stable, and portable lensless digital holographic (DH) microscopy method is presented relying on the Fresnel diffraction (FD) of light from a phase discontinuity (PD). A phase plate in the transmission or a physical step in the reflection can be employed in the path of the divergent beam of a coherent light source as a component imposing the PD. The recorded diffraction pattern in the vicinity of the PD is a hologram produced by off-axis overlapping of two diffracted waves in both sides of the boundary region with adjustable fringe modulation. To validate the method, measurements are performed on the amplitude and phase specimens as well as on the dynamic processes of water evaporation and 3D tracking of floating cells. A reflective configuration of FD from a physical step can be used as a powerful platform for lensless DH microscopy using high-energy electromagnetic radiation, e.g., x-ray and UV sources for the high-resolution imaging of moving samples.

Improvement of electron beam quality in laser wakefield acceleration by a circularly-polarized laser pulse

Electron acceleration driven by laser wakefield using a laser pulse with circular polarization is studied to generate better-quality electron bunches. In order to inject electrons into the accelerating phase of the plasma wave, a density transition shaped bump is employed. Using particle-in-cell simulations, we demonstrate the influence of laser polarization on the quality of electron bunch. The simulation results (using experimentally achievable parameters) show that the electron bunch with higher peak-energy, narrow energy-spread, and low emittance can be obtained by using a laser pulse with circular polarization as compared to the usually employed linear polarization in a mm-scale length plasma. The results show the improved quality of the electron bunch generated from laser wakefield accelerations. The predicted electron bunch quality may be crucial in developing plasma-based electromagnetic radiation sources.

Development of an automated source port in IoT for application in industrial process tomography

Computed tomography technology uses an electromagnetic radiation source or particulate radiation source, to analyze / study different samples that can range from living organisms to the most diverse objects (rocks, phantoms, etc.). The use of the radioactive materials may cause harm to the operator if he is exposed to the source of radiation, so aiming at the safety of the operator, the objective of this work is to develop an Internet of Things automation system for the opening of the Industrial Process Tomography source port for industrial tomography applications. Thus, this system can drive the stepper motors through this platform can be opened at a safe distance to the operator, avoiding the operator to take radiation dose to perform this operation. For the IPT project, five source ports were made so that each was positioned diametrically opposite each array of detectors. In this project we used 192Ir sources that have activity of 18,500 MBq and that were produced in the reactor IEA-R1, from the neutron bombardment of the pellet containing stable isotope 191Ir. The main characteristics of 192Ir are: half-life of 74.2 days; radiation energy from 0.13 to 0.65 MeV. For the safety of the operator during the opening of the sources, an automated opening system with IoT that can be activated with software installed on the tomography or by a smartphone application by the MQTT protocol, which makes it possible to be monitored in real time at long distance showing the opening and closing status of each source port.

The effects of base station as an electromagnetic radiation source on flower and cone yield and germination percentage in Pinus brutia Ten.

Electromagnetic radiation is a substantial pollution factor that most of the living things found almost everywhere are constantly exposed to with current technology. The number of studies conducted on the effects of this exposed radiation on the living things constantly is limited; and almost all of the studies conducted are aimed at measuring the effects of short-term exposure. In addition to this, most of the studies conducted on plants focus on herbaceous plant species. In this study, the effects of distance to base station on flower and cone yield and germination percentage were investigated in Pinus brutia individuals, one of the critical forest tree species. The study results revealed that being close to the base station significantly reduced the number of flowers and cones in P. brutia individuals, and that the values obtained in individuals at a distance of 800m from the base station were 11 times more than the number of flowers and 7 times more than the number of cones compared to the individuals at a distance of 100m. In the seeds subject to the study, there is a three-times difference in terms of the germination percentage among the individuals located at the furthest and closest distance to the base station. These results show that P. brutia individuals are considerably affected by the base station.

Electromagnetic Compatibility Analysis and Optimization Design of Switching Power Supply Printed Circuit Board

Printed Circuit Board (PCB) is not only an important electrical module of information equipment, but also an important source of electromagnetic radiation. Only when PCB works normally and is compatible with other electrical equipment, the whole information equipment can work normally. Because of the complexity of PCB structure and the difficulty of modeling, the EMC (Electromagnetic Compatibility) analysis of PCB is very difficult. For this reason, Taking the widely used full bridge current double rectifier converter as an example, aiming at the electromagnetic compatibility problems caused by the PCB design of the switching power supply, this paper proposes a simulation method based on the electromagnetic field by establishing the near-field radiation model of the PCB, analyzes the areas with high radiation intensity in the PCB layout, by optimizing the layout and wiring of the PCB, the electromagnetic compatibility performance of the switching power supply is improved. The simulation results show that the near-field radiation characteristics of PCB can be predicted by introducing the electromagnetic field simulation method in the design stage, according to the characteristics of the magnetic field, the optimal design is realized, so that the EMC of the switching power supply reaches the standard, and finally the working performance of the switching power supply is improved.

Evaluation of Electromagnetic Radiation level in the Outdoor from Wireless Transmission Systems in Northern West Bank – Palestine

Exposure to electromagnetic fields is a major public concern due to the possible hazardous effects on health caused by exposure to these radiations. The aims of this study were to measure radiofrequency radiation levels from different wireless systems and to compare the results with the recommended limits by the World Health Organization (WHO) which should be less that 450 µw/cm2. The study was a cross-sectional study that was conducted in different cities and villages from the northern governorates in the West Bank; Jenin, Tulkarm, Nablus, Qalqilya, Tubas and Salfit. To measure the radiation levels ranging from 80 MHz to 2 GHz, a Portable Field Strength Meter with the suitable set of antennas was used. This frequency range covers the radiations from different sources as mobile phone base stations, local radio and television stations, mobile phones, Wireless Local Area Network, Bluetooth, wireless computer periphery and even microwave ovens. Points close to mobile phone base stations and local radio and television stations in addition to randomly selected points were included. The scanning process for each point was done twice and the higher reading was included in the analysis. The results were compared to the recommended limits of radiations by WHO. Also, a questionnaire was distributed to evaluate people knowledge and perception regarding radiations. A total of 2000 readings were obtained with a mean ± SD = 0.25 ± 0.214 µw/cm2. The highest reading was 1.91 µw/cm2. All the readings were below the limits of radiations recommended by the WHO. Most of the readings in the tested area 1184 (59.2%) were between 0.1 -0.45 µw/cm2 which are 1000- 4500 time less than the maximum allowed level (450 µw/cm2), 527 (26.35%) readings were <0.1 µw/cm2, 271 (13.55%) reading were between 0.45-1 µw/cm2 and the rest 17 (0.85%) were >1 µw/cm2 which were still 236-450 times less than the allowed WHO level. Regarding the questionnaire part, most of the participants use mobile phones frequently, they think radiations are dangerous and can cause cancer, they prefer not to have mobile base stations close to their living places. In this study, a scanning for all electromagnetic radiation sources caused by different sources of wireless communication systems showed theoretically no dangerous radiation levels and all the recorded levels were much lower than the recommended levels by the WHO. Most people feel afraid from radiations and think they are dangerous.

Evaluation of Electromagnetic Radiation level in the Outdoor from Wireless Transmission Systems in Northern West Bank – Palestine

Exposure to electromagnetic fields is a major public concern due to the possible hazardous effects on health caused by exposure to these radiations. The aims of this study were to measure radiofrequency radiation levels from different wireless systems and to compare the results with the recommended limits by the World Health Organization (WHO) which should be less that 450 µw/cm2. The study was a cross-sectional study that was conducted in different cities and villages from the northern governorates in the West Bank; Jenin, Tulkarm, Nablus, Qalqilya, Tubas and Salfit. To measure the radiation levels ranging from 80 MHz to 2 GHz, a Portable Field Strength Meter with the suitable set of antennas was used. This frequency range covers the radiations from different sources as mobile phone base stations, local radio and television stations, mobile phones, Wireless Local Area Network, Bluetooth, wireless computer periphery and even microwave ovens. Points close to mobile phone base stations and local radio and television stations in addition to randomly selected points were included. The scanning process for each point was done twice and the higher reading was included in the analysis. The results were compared to the recommended limits of radiations by WHO. Also, a questionnaire was distributed to evaluate people knowledge and perception regarding radiations. A total of 2000 readings were obtained with a mean ± SD = 0.25 ± 0.214 µw/cm2. The highest reading was 1.91 µw/cm2. All the readings were below the limits of radiations recommended by the WHO. Most of the readings in the tested area 1184 (59.2%) were between 0.1 -0.45 µw/cm2 which are 1000- 4500 time less than the maximum allowed level (450 µw/cm2), 527 (26.35%) readings were <0.1 µw/cm2, 271 (13.55%) reading were between 0.45-1 µw/cm2 and the rest 17 (0.85%) were >1 µw/cm2 which were still 236-450 times less than the allowed WHO level. Regarding the questionnaire part, most of the participants use mobile phones frequently, they think radiations are dangerous and can cause cancer, they prefer not to have mobile base stations close to their living places. In this study, a scanning for all electromagnetic radiation sources caused by different sources of wireless communication systems showed theoretically no dangerous radiation levels and all the recorded levels were much lower than the recommended levels by the WHO. Most people feel afraid from radiations and think they are dangerous.

Design and Performance Evaluation of a Home Energy Management System for Power Saving

In the context of the ongoing global warming, with environmental concerns regarding the greenhouse gas emissions due to our increasing energy consumption, smart energy management solutions have gained popularity as they have the potential to reduce our impact on the environment and also on our budgets. This paper proposes one of the most affordable designs for an autonomous, microcontroller-based demand-side energy management system to be installed in a home environment where it reduces the standby power consumed by the controlled devices. As a secondary function, it monitors and controls the lights to further save energy. The proposed system is designed to operate independently and also to limit the new wireless sources of electro-magnetic radiation introduced in the home environment. Six homes have been analyzed in terms of the measured energy consumption and to evaluate the energy management capabilities of the system, a prototype was built and tested. Promising results have been obtained and are detailed in the Results and Conclusion sections. A very low purchase price and good performance make this design a viable solution for intelligent home energy management, in today’s economic context.

MODULATION OF STAPHYLOCOCCUS AUREUS BIOFILM BY ELECTROMAGNETIC RADIATION

Mobile communication systems are undoubtedly an environmental source of electromagnetic radiation (EMR). Although the direct health effect of a cell phone to human is still elusive, the effect to unicellular organisms is rather apparent. The aim of this study was to examine the effects of EMR on development of bacterial biofilm. Microtitration plates with four strains of Staphylococcus aureus were exposed to electromagnetic field of frequencies 1-5 GHz, which are used in mobile phones. The results showed mostly the inhibition of the development biofilm activity at frequencies 1, 2 and 3 GHz, however the significant stimulation of biofilm development occurred at frequencies 4 and 5 GHz. Our observations demonstrate that EMR exposure produced modulation effects on bacterial biofilms, which are very important in commensal and pathogen bacteria.

DETECTION OF PULSARS AMONG NEUTRON STARS AND 
 ELECTROMAGNETIC RADIATION SOURCES USING MACHINE LEARNING METHODS

This article describes a way to simplify the process of confirming hypotheses about whether the source of electromagnetic radiation is a pulsar by using modern machine learning methods. In the course of the work, data from more than 17,000 radiation sources were analyzed and an image recognition algorithm that detects pulsars with an accuracy of up to 98 % was used

Comparative Analysis of Methods and Model of Protection Against Electromagnetic Fields in Cellular Communication

The impacts of electromagnetic radiation (EMR) of cellular phones on the human body are studied worldwide. Some groups of scientists claim that the use of cellular phones leads to diseases that have a latent period of development. In this regard, measures are necessary in order to reduce the impact of EMR on humans in advance. Reducing the EMR impact on the body of a biological object can be achieved in various ways. One of the directions is the development of shielding materials and the mathematical simulation of the distribution of EMR sources in order to prevent people from getting into their biologically hazardous areas. In the conducted study, fuzzy logic has been used to simulate the calculation of the biologically hazardous area radius. The Mamdani fuzzy inference algorithm has been used as a fuzzy output model. A comparative analysis based on the Mean Absolute Percentage Error (MAPE) indices and the accuracy with regression models has demonstrated that the developed model is 4% superior over them.

Lasing Spaser in Photonic Crystals.

Plasmonic nanolasers (spasers) are of intense interest, attributable to their ability to generate a high-intensity coherent radiation. We infiltrated a three-dimensional silica-based photonic crystal (PhC) film with spasers, composed of spherical gold cores, surrounded by silica shells with dye molecules. In spasers, the gold nanospheres supported the surface plasmons and the dye molecules transferred incoming optical energy to the surface plasmons. Our experiments show that such a structure, consisting of a PhC, which acts as an external distributed feedback resonator, and spasers, can serve as a coherent source of electromagnetic radiation. Spasers were locked in phase by the common radiation causing a phenomenon called the lasing spaser: the emission of spatially and temporarily coherent light normal to the surface of the PhC film. The far-field radiation patterns appeared in the shape of the Star-of-David, which is due to the dispersion along the Brillouin zone boundary. The infiltration of the spasers into the PhC led to drastic narrowing of the emission peak and an 80-fold decrease in the spaser generation threshold with respect to the same spasers in a suspension at room temperature.

МЕРОПРИЯТИЯ МЕДИЦИНСКОГО КОНТРОЛЯ В СИСТЕМЕ ОБЕСПЕЧЕНИЯ БЕЗОПАСНОСТИ ВОЕННОСЛУЖАЩИХ, ГРАЖДАНСКОГО ПЕРСОНАЛА, НАСЕЛЕНИЯ ПРИ ЭКСПЛУАТАЦИИ ПЕРЕДАЮЩИХ РАДИОТЕХНИЧЕСКИХ ОБЪЕКТОВ В ВОИНСКОЙ ЧАСТИ

The article presents an overview of the basic requirements for objects that are sources of electromagnetic radiation in the radio frequency range, a brief technical characteristics of radar stations, and the peculiarities of the effect of microwave radiation on the human body. Measures of medical control are recommended, carried out during the commissioning of radar stations, certification, as well as the organization of production control.

Detecting Electromagnetic Geographical Environment Changes Based on the Frequency‐Intensity Curve

Electromagnetic geographic environment is closely related to human life. With continuous popularization of public infrastructures and daily electronic instruments, such as electric power communication systems and household appliances, electromagnetic radiation sources have increased sharply in the geographic environment, which leads to increasingly serious electromagnetic radiation pollution. Thus, it is significant to monitor, evaluate, and analyze the electromagnetic radiation condition and explore its changing law in the environment. However, the traditional monitoring method can only detect anomalies within certain frequencies in the fixed stations. To fill this gap, this research first develops a vehicle‐mounted electromagnetic environment monitoring system to collect both spatial positioning data and electromagnetic data of the whole frequency range. The acquired data are then used to construct the location‐based frequency‐intensity curve to reflect the variation of electromagnetic radiation at different frequency ranges. On this basis, a curve similarity measurement method is introduced to analyze the similarity of different curves, which is effective to diagnose time‐varying sources from both global and local perspectives. This research provides a real‐time mobile monitoring method, which is significant to know the dynamic variation of local electromagnetic environment and promotes subsequent comprehensive geographic analyses.

Electromagnetic and acoustic technologies in antibacterial preparation development

Subject and Purpose. The present paper is concerned with the use of wave technologies in the development of antibiotics-alternative approaches for pathogenic microflora suppression. Lactobacilli strains picked in different ecological niches and their activity against pathogenic strains are studied with a focus on a targeted modification of adhesive and antagonistic properties of lactobacilli by exposing them to low-intensity electromagnetic (EM) fields and the ultrasound. Methods and Methodology. Lactobacilli picked in different ecological niches are experimentally studied, including (1) standard strains from probiotic preparations and (2) circulating strains picked in humans and bees. For the ultrasonic and electromagnetic radiation sources, G3-109 and G3-F and G4-141 and G4-142 generators are taken, respectively. The adhesive properties of Lactobacillus spp. strains and their antagonistic activity are estimated against C. diphtheriae, S. aureus and yeast-like fungi of Candida genus in aerobic and microaerophilic culture conditions. Statistical technology is employed in the data processing and analysis. Results. It has been established that L. plantarum strains picked in the gut of healthy bees are most antagonistic towards pathogens. It has been demonstrated that the priority culture conditions for lactobacilli are microaerophilic conditions simulating their stay in vivo. It has been shown that it is possible to modify properties of microorganisms by their exposure to ultrasound and low-intensity electromagnetic fields in narrow bands of the EHF range. The effect efficiency versus frequency has a dispersion character. Individual features of various pathogenic strains have been recognized. Conclusion. The obtained results open up prospects for electromagnetic and acoustic technologies in the development of safe alternative means to antagonize persisting pathogens and increase human body resilience.

Terahertz Scanning Reflectometer for Structure Visualization of Polymer Constructions in Additive Manufacturing

The results of the development and practical application of a quasi-optical system for reflectometry of objects in the terahertz frequency range for analyzing the structure in additive manufacturing of objects are presented. A backward-wave oscillator is used for continuous generation of electromagnetic radiation; an acousto-optic converter (Golay cell) is applied as a detector. The reflectometer is controlled by personal computer through the L-card E 154 input-output module and the standard digital-to-analog converter of the STD-21 spectrometer. The system is tested at the frequency of 874 GHz on the 3D-printed composite structure sample. Our paper is terahertz reflectometer with a source of continuous monochromatic electromagnetic radiation based on a backward wave oscillator is presented. The purpose of this work in creating a scanning THz reflectometer is considered to have been achieved. At the same time, the following tasks are solved: a quasi-optical scheme of the reflectometer is selected and assembled; the hardware part of the system (all mechanisms and components) is implemented; a program for controlling the radiation intensity registration system is adapted for this task; the test sample is manufactured using 3D printing technology, the THz reflectometer is tested. The obtained practical results of registration of the two-dimensional distribution of the reflection coefficient show that the use of THz radiation is promising for visualizing the structure of structures obtained by additive technology. Further development of the project is planned by changing the construction of the positioning mechanism, which will provide micrometric calibration of the sample holder relative to the diaphragm. The use of the quasi-optical scheme of the two-beam interferometer for recording the phase distribution and amplitude of reflected THz radiation will allow obtaining information about the spatial location of defects (inhomogeneities) of products obtained by additive technology.

Ali sinir sisteminin tipləri və emosional gərginlik arasında fizioloji qanunauyğunluqların tədris prosesində rolu

The article examines the mechanisms of the relationship between the types of higher nervous system and emotional tension. Increased emotional stress as a result of modern technological development, decreased physical activity, hypokinesia, increased exposure to closed sources of electromagnetic radiation, impaired health, increased number of failures due to mental fatigue, impaired socialization due to distance education and work, is growing. The study of physiological patterns between types of higher nervous activity and emotional tension remains relevant, and there are still many unanswered questions. In addition to the type of higher nervous system, the development of individuals individually creates conditions for more stable behavior and the manifestation of psychological indicators.

Mode of use by mobile phone and change of time of simple audio-motor reaction for users of mobile communication. Age related features of ipsilateral and contralateral effects

By analysing the time of a simple auditory-motor reaction with mono-presentation of an audio signal, the effect of the electromagnetic radiation of a mobile phone on the human auditory system is evaluated. Regularities in the frequency of occurrence of ipsi and contralateral effects in mobile users of different age groups are obtained. This study has no analogues in either Russian or foreign publications and is currently exclusive. The purpose was to study age-related features of the severity of ipsi and contralateral effects, depending on the mode of use of the mobile phone. To record the ipsi- and contralateral effects, we used the differences in the average values of a simple auditory-motor reaction between the left and right ears with mono-presentation of the sound signal of 573 respondents of different age groups. The obtained values were compared with the control group data for each age group (491 respondents). If the difference was greater than in the control group, the ipsilateral or contralateral effect was recorded. The severity of the effect was evaluated taking into account the lateral preferences of each participant in the experiments (to which ear the mobile phone is most often held) and the mode of use of the mobile phone. Statistical processing of the results was carried out using the non-parametric Mann-Whitney test and the method of descriptive statistics: prevalence indicator (Pr) (relative frequency of manifestation of a particular attribute in the sample). The comparison of the severity of ipsi and contralateral effects for different age groups allowed us to establish the following patterns. It was found that, in general, the manifestation of the contralateral effect decreases with age, and the ipsilateral effect increases. However, this change is not linear. It is shown that the features of the manifestation of the contralateral and ipsilateral effect for each age group depend both on the time of daily use of a mobile phone and on the total duration of use of a mobile phone. We believe that when studying multidimensional input data, an individual approach is necessary. The presented results confirm the negative effect of the radiation of mobile phones on the auditory system, primarily of our younger generation. Given the special vulnerability of children to physical environmental factors and the depth of penetration of EMR MT into the brain of a child, we believe that from a radiobiological point of view, there is already a need to develop a special SanPiN (sanitary rules and norms) for all available modern low-intensity sources of electromagnetic radiation, including Wi-Fi.

Non-isolated sources of electromagnetic radiation by multipole decomposition for photonic quantum technologies on a chip with nanoscale apertures.

The creation of single photon sources on a chip is a mid-term milestone on the road to chip-scale quantum computing. An in-depth understanding of the extended multipole decomposition of non-isolated sources of electromagnetic radiation is not only relevant for a microscopic description of fundamental phenomena, such as light propagation in a medium, but also for emerging applications such as single-photon sources. To design single photon emitters on a chip, we consider a ridge dielectric waveguide perturbed with a cylindrical inclusion. For this, we expanded classical multipole decomposition that allows simplifying and interpreting complex optical interactions in an intuitive manner to make it suitable for analyzing light-matter interactions with non-isolated objects that are parts of a larger network, e.g. individual components such as a single photon source of an optical chip. It is shown that our formalism can be used to design single photon sources on a chip.

Study and Modeling of Human Biological Tissue Exposed to High Frequency Electromagnetic Waves

The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the experimental values in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.