scholarly journals Numerical Calculation of Electric Fields in Housing Spaces Due to Electromagnetic Radiation from Antennas for Mobile Communication

10.14311/478 ◽  
2003 ◽  
Vol 43 (5) ◽  
Author(s):  
H.-P. Geromiller ◽  
A. Farschtschi
Keyword(s):  
Electromagnetic Wave ◽  
Electric Field ◽  
Electromagnetic Radiation ◽  
Electric Fields ◽  
Mobile Communication ◽  
Signal Frequency ◽  
High Signal ◽  
Maximum Value ◽  
Mobile Antennas ◽  
The Impact

The influence of electromagnetic radiation from mobile antennas on humans is under discussion in va'rious groups ofscientists, This paper deals with the impact ofelectromagnetic radiation in a housing space. The space is assumedto be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetically transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source ofradiation is considered to be far away from the housing, the radiation is regarded to be from a plane wave. Due to the high signal frequency and ferroconcrete walls, 5 sides ofthe housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.

scholarly journals Numerical Calculation of Electric Fields in Housing Spaces due to Electromagnetic Radiation from Antennas for Mobile Communication

10.14311/580 ◽  
2004 ◽  
Vol 44 (3) ◽  
Author(s):  
H.-P. Geromiller ◽  
A. Farschtschi
Keyword(s):  
Electromagnetic Wave ◽  
Electric Field ◽  
Electromagnetic Radiation ◽  
Electric Fields ◽  
Mobile Communication ◽  
Signal Frequency ◽  
High Signal ◽  
Maximum Value ◽  
Mobile Antennas ◽  
The Impact

The influence of electromagnetic radiation from mobile antennas on humans is under discussion in various group of scientists. This paper deals with the impact of electromagnetic radiation in housing spaces. The space is assumed to be bordered by 5 walls of ferroconcrete and a door-window combination on the 6th side, the latter to be electromagnetic transparent. The transparent side of the housing is exposed to an electromagnetic wave. As the source of radiation is considered to be far away from the housing, the radiation is regarded as a plane wave. Due to the high signal frequency and the ferroconcrete walls, 5 sides of the housing space are considered to be perfect conductors. The electric field inside the housing is calculated numerically by the method of finite differences for different angles of incidence of the radiated electromagnetic wave. The maximum value of the calculated electric field is outlined in a diagram.

scholarly journals Restraining Surface Charge Accumulation and Enhancing Surface Flashover Voltage through Dielectric Coating

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 750
Author(s):  
Jixing Sun ◽  
Sibo Song ◽  
Xiyu Li ◽  
Yunlong Lv ◽  
Jiayi Ren ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Electric Fields ◽  
Transition Process ◽  
Metallic Particle ◽  
Particle Charging ◽  
Insulating Surfaces ◽  
Surface Flashover ◽  
Charging Time ◽  
The Impact

A conductive metallic particle in a gas-insulated metal-enclosed system can charge through conduction or induction and move between electrodes or on insulating surfaces, which may lead to breakdown and flashover. The charge on the metallic particle and the charging time vary depending on the spatial electric field intensity, the particle shape, and the electrode surface coating. The charged metallic particle can move between the electrodes under the influence of the spatial electric field, and it can discharge and become electrically conductive when colliding with the electrodes, thus changing its charge. This process and its factors are mainly affected by the coating condition of the colliding electrode. In addition, the interface characteristics affect the particle when it is near the insulator. The charge transition process also changes due to the electric field strength and the particle charging state. This paper explores the impact of the coating material on particle charging characteristics, movement, and discharge. Particle charging, movement, and charge transfer in DC, AC, and superimposed electric fields are summarized. Furthermore, the effects of conductive particles on discharge characteristics are compared between coated and bare electrodes. The reviewed studies demonstrate that the coating can effectively reduce particle charge and thus the probability of discharge. The presented research results can provide theoretical support and data for studying charge transfer theory and design optimization in a gas-insulated system.

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.

Assessing The Risk Associated with Simultaneous Exposure To Mobile Communication Signals Within 900–2500 MHz in Nigeria

2020 ◽  
Author(s):  
B O Ayinmode ◽  
I P Farai
Keyword(s):  
Ionizing Radiation ◽  
Field Strength ◽  
Electric Field ◽  
Mobile Communication ◽  
Base Station ◽  
Simultaneous Exposure ◽  
Communication Signals ◽  
Frequency Bands ◽  
Maximum Value ◽  
Total Electric Field

Abstract In this study, the total exposure due to signals within GSM 900, GSM 1800, CDMA-1900 and 3G-2100 frequency bands at 200 m from the foot of 120, 100 and 80 base station masts in the Nigerian cities of Lagos, Ibadan and Abuja, respectively, was assessed. A calibrated hand-held spectrum analyser was used to measure the level of power (in dBm) of each signal within the mobile frequency bands. The exposure quotient associated with the combine electric field strengths from the various frequency bands in each city was estimated. The maximum value of total electric field strength at each point in Lagos, Ibadan and Abuja was 0.83 V/m, 0.53 V/m and 1.63 V/m, respectively. This study shows that the exposure quotient due to the simultaneous exposure to the four bands of mobile communication signals in each city is far less than one, as recommend by International Commission on Non-Ionizing Radiation Protection.

scholarly journals Impact of disturbance electric fields in the evening on prereversal vertical drift and spread F developments in the equatorial ionosphere

2018 ◽  
Vol 36 (2) ◽  
pp. 609-620 ◽  
Author(s):  
Mangalathayil A. Abdu ◽  
Paulo A. B. Nogueira ◽  
Angela M. Santos ◽  
Jonas R. de Souza ◽  
Inez S. Batista ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Plasma Bubble ◽  
Large Variability ◽  
Plasma Drift ◽  
F Region ◽  
Vertical Drift ◽  
Spread F ◽  
The Impact ◽  
Magnetic Disturbances

Abstract. Equatorial plasma bubble/spread F irregularity occurrence can present large variability depending upon the intensity of the evening prereversal enhancement in the zonal electric field (PRE), that is, the F region vertical plasma drift, which basically drives the post-sunset irregularity development. Forcing from magnetospheric disturbances is an important source of modification and variability in the PRE vertical drift and of the associated bubble development. Although the roles of magnetospheric disturbance time penetration electric fields in the bubble irregularity development have been studied in the literature, many details regarding the nature of the interaction between the penetration electric fields and the PRE vertical drift still lack our understanding. In this paper we have analyzed data on F layer heights and vertical drifts obtained from digisondes operated in Brazil to investigate the connection between magnetic disturbances occurring during and preceding sunset and the consequent variabilities in the PRE vertical drift and associated equatorial spread F (ESF) development. The impact of the prompt penetration under-shielding eastward electric field and that of the over-shielding, and disturbance dynamo, westward electric field on the evolution of the evening PRE vertical drift and thereby on the ESF development are briefly examined. Keywords. Ionosphere (ionospheric irregularities)

Effectiveness of Pulsed Electric Fields in Controlling Microbial Growth in Milk

2008 ◽  
Vol 4 (7) ◽  
Author(s):  
Adedayo Otunola ◽  
Ayman El-Hag ◽  
Shesha Jayaram ◽  
William A Anderson
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
Milk Fat ◽  
Indigenous Population ◽  
Inoculum Size ◽  
Microbial Inactivation ◽  
Log Reduction ◽  
The Impact

A study was conducted to assess the effectiveness of pulsed electric field (PEF) inactivation of a heterogeneous community of microbes. The aim was to assess the impact of process parameters on an indigenous population of microbes present in milk, rather than pure cultures used in other studies. Tests over an electric field strength range of 10 – 40 kV/cm and 10 to 120 pulses per millilitre showed that high electric field strength and pulse number inactivated microbes by up to approximately 2 log. Inoculum size affected PEF effectiveness when only a few pulses were applied. A significant log-reduction was achieved against the indigenous microbes found in milk that were apparently recalcitrant to commercial pasteurization. Microbial inactivation was more extensive when E. coli was not added to the indigenous population, indicating that the added pure culture was more resistant than the indigenous microbes. The milk fat content had a significant negative effect on the extent of log-reduction for indigenous microbes, when 2% and 18% levels were compared.

Analysis of Optically Induced Fluid Flows in Electric Fields

2008 ◽  
Author(s):  
Edward Judokusumo ◽  
Aloke Kumar ◽  
Stuart Williams ◽  
Steve Wereley
Keyword(s):  
Electric Field ◽  
Laser Beam ◽  
Electric Fields ◽  
Continuous Wave ◽  
Fluid Flows ◽  
Analytical Models ◽  
Signal Frequency ◽  
Illumination System ◽  
Source Type ◽  
Microfluidic Mixers

In this paper we demonstrate opto-electrothermal pumping in a very simple setup consisting primarily of parallel electrodes and explore the characteristics of such flows with different optical intensity patterns. For our parallel electrode configuration setup, ITO-coated electrodes were used to generate electric fields. The optical illumination system uses a laser beam (continuous wave, 1,064 nm). The experiments are analyzed in terms of existing analytical models for electrothermal flows. Microvortices created using the electric field and focused laser beam resembles a sink/source type flow with the laser spot as the center of the sink/source. The flow velocity is characterized as a function of the AC signal frequency and the strength of electric field. At larger frequencies (f > 1 MHz), the velocity of the vortices decreases and around f > 5 MHz, Brownian motion dominates fluid flow. The line illumination is created by holographically stretching the point illumination. The line is about 28 μm in length. Result of this experiment is determined by means of visualization only. The creation of these vortices can not only be used to create microfluidic pumps but also also show immense promise as microfluidic mixers without utilizaing any invasive components.

SPACE-TIME EVOLUTION OF ELECTRIC FIELDS IN CORES OF COMPACT STARS

2012 ◽  
Vol 12 ◽  
pp. 193-197
Author(s):  
WEN-BIAO HAN ◽  
REMO RUFFINI ◽  
SHE-SHENG XUE
Keyword(s):  
Electric Field ◽  
Electromagnetic Radiation ◽  
Time Evolution ◽  
Electron Density ◽  
Electric Fields ◽  
Gravitational Collapse ◽  
Space Time ◽  
Compact Stars ◽  
Equilibrium Configurations ◽  
Space Time Evolution

Studying the electrodynamics of proton and electron fluids in cores of compact stars, we find oscillations of electron density and electric field around their equilibrium configurations, provided cores undergo a pulsation or trigger of gravitational collapse. These field and density oscillations can possibly lead to observable electromagnetic radiation.

scholarly journals Comparative Analysis of the Various Generalized Ohm's Law Terms in Magnetosheath Turbulence as Observed by Magnetospheric Multiscale

2021 ◽  
Author(s):  
Julia Stawarz ◽  
Lorenzo Matteini ◽  
Tulasi Parashar ◽  
Luca Franci ◽  
Jonathan Eastwood ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Electron Mass ◽  
Turbulent Fluctuation ◽  
Electron Pressure ◽  
Ohm’S Law ◽  
Magnetospheric Multiscale ◽  
Ohm's Law ◽  
Turbulent Plasmas ◽  
The Impact

<p><span>Electric fields (<strong>E</strong>) play a fundamental role in facilitating the exchange of energy between the electromagnetic fields and the changed particles within a plasma. </span>Decomposing <strong>E</strong> into the contributions from the different terms in generalized Ohm's law, therefore, provides key insight into both the nonlinear and dissipative dynamics across the full range of scales within a plasma. Using the unique, high‐resolution, multi‐spacecraft measurements of three intervals in Earth's magnetosheath from the Magnetospheric Multiscale mission, the influence of the magnetohydrodynamic, Hall, electron pressure, and electron inertia terms from Ohm's law, as well as the impact of a finite electron mass, on the turbulent electric field<strong> </strong>spectrum are examined observationally for the first time. The magnetohydrodynamic, Hall, and electron pressure terms are the dominant contributions to <strong>E</strong> over the accessible length scales, which extend to scales smaller than the electron gyroradius at the greatest extent, with the Hall and electron pressure terms dominating at sub‐ion scales. The strength of the non‐ideal electron pressure contribution is stronger than expected from linear kinetic Alfvén waves and a partial anti‐alignment with the Hall electric field is present, linked to the relative importance of electron diamagnetic currents within the turbulence. The relative contributions of linear and nonlinear electric fields scale with the turbulent fluctuation amplitude, with nonlinear contributions playing the dominant role in shaping <strong>E</strong> for the intervals examined in this study. Overall, the sum of the Ohm's law terms and measured <strong>E</strong> agree to within ∼ 20% across the observable scales. The results both confirm a number of general expectations about the behavior of <strong>E</strong> within turbulent plasmas, as well as highlight additional features that may help to disentangle the complex dynamics of turbulent plasmas and should be explored further theoretically.</p>

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