scholarly journals Modelling and assessment of the electric field strength caused by mobile phone to the human head

2016 ◽  
Vol 73 (6) ◽  
pp. 538-543 ◽  
Author(s):  
Raimondas Buckus ◽  
Birute Strukcinskiene ◽  
Juozas Raistenskis ◽  
Rimantas Stukas
Keyword(s):  
Electromagnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Mobile Phone ◽  
Electric Field Strength ◽  
Mobile Phones ◽  
Frequency Band ◽  
Human Head ◽  
Field Exposure ◽  
Head Surface

Background/Aim. Electromagnetic field exposure is the one of the most important physical agents that actively affects live organisms and environment. Active use of mobile phones influences the increase of electromagnetic field radiation. The aim of the study was to measure and assess the electric field strength caused by mobile phones to the human head. Methods. In this paper the software ?COMSOL Multiphysics? was used to establish the electric field strength created by mobile phones around the head. Results. The second generation (2G) Global System for Mobile (GSM) phones that operate in the frequency band of 900 MHz and reach the power of 2 W have a stronger electric field than (2G) GSM mobile phones that operate in the higher frequency band of 1,800 MHz and reach the power up to 1 W during conversation. The third generation of (3G) UMTS smart phones that effectively use high (2,100 MHz) radio frequency band emit the smallest electric field strength values during conversation. The highest electric field strength created by mobile phones is around the ear, i.e. the mobile phone location. The strength of mobile phone electric field on the phantom head decreases exponentially while moving sidewards from the center of the effect zone (the ear), and constitutes 1-12% of the artificial head?s surface. Conclusion. The highest electric field strength values of mobile phones are associated with their higher power, bigger specific energy absorption rate (SAR) and lower frequency of mobile phone. The stronger electric field emitted by the more powerful mobile phones takes a higher percentage of the head surface. The highest electric field strength created by mobile phones is distributed over the user ear.

scholarly journals The assessment of electromagnetic field radiation exposure for mobile phone users

2014 ◽  
Vol 71 (12) ◽  
pp. 1138-1143 ◽  
Author(s):  
Raimondas Buckus ◽  
Birute Strukcinskiene ◽  
Juozas Raistenskis
Keyword(s):  
Electromagnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Mobile Phone ◽  
Radiation Exposure ◽  
Electric Field Strength ◽  
Rural Area ◽  
Mobile Phones ◽  
Field Radiation ◽  
Made In

Background/Aim. During recent years, the widespread use of mobile phones has resulted in increased human exposure to electromagnetic field radiation and to health risks. Increased usage of mobile phones at the close proximity raises questions and doubts in safety of mobile phone users. The aim of the study was to assess an electromagnetic field radiation exposure for mobile phone users by measuring electromagnetic field strength in different settings at the distance of 1 to 30 cm from the mobile user. Methods. In this paper, the measurements of electric field strength exposure were conducted on different brand of mobile phones by the call-related factors: urban/rural area, indoor/outdoor setting and moving/stationary mode during calls. The different types of mobile phone were placed facing the field probe at 1 cm, 10 cm, 20 cm and 30 cm distance. Results. The highest electric field strength was recorded for calls made in rural area (indoors) while the lowest electric field strength was recorded for calls made in urban area (outdoors). Calls made from a phone in a moving car gave a similar result like for indoor calls; however, calls made from a phone in a moving car exposed electric field strength two times more than that of calls in a standing (motionless) position. Conclusion. Electromagnetic field radiation depends on mobile phone power class and factors, like urban or rural area, outdoor or indoor, moving or motionless position, and the distance of the mobile phone from the phone user. It is recommended to keep a mobile phone in the safe distance of 10, 20 or 30 cm from the body (especially head) during the calls.

scholarly journals Assessment of Radiofrequency Radiation Exposure Levels from Mobile Phones and Wireless Hotspots in Some Parts of Makurdi-Nigeria

2020 ◽  
Vol 3 (3b) ◽  
pp. 138-143
Author(s):  
NB Akaagerger ◽  
DK Kaki ◽  
AI Philip ◽  
BA Ikyo
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Power Density ◽  
Mobile Phones ◽  
Radio Waves ◽  
Safety Level ◽  
The Public ◽  
State Measurement ◽  
Exposure Levels

Radio waves and Microwaves also known as Radio Frequency Radiations (RFR) have been associated with health hazards. This research was carried out to assess the safety level of these radiations in Makurdi, Benue State. Measurement of RFR power density and electric field strength were carried out for mobile phones. A Cornet 15SA Electrosmog meter was used for assessing RFR exposure levels. Measurements of RFR power density (mWm-2) and electric field strength (Vm-1) for wireless hotspots were carried out within 10m radius to offices and open areas with high occupancy. Radiation levels from mobile phones were measured on the surface with mobile phones in contact with the meter in a normal direction such that maximum readings are obtained. A survey questionnaire was also designed to assess the level of knowledge of the residents concerning the effects of exposure to RF radiations. The field strength and Power density from mobile phones were found to range from 0.1946 Vm-1 to 26.2446 Vm-1 and 0.1004 mWm-2 to 1.827 Wm-2 respectively. These are within ICNIRP recommended value of 10 Wm-2 for members of the public. Environmental levels of RFR in areas with RFR generating devices showed that RFR levels ranged from 5.0595Vm-1 (0.0679 Wm-1) to 7.3961Vm-1 (0.145 Wm1). Also, assessment of areas with Wi-Fi hotspots showed that the presence of hotspots significantly increased background levels of RFR. These values were compared with measurements carried out in areas without RF devices which ranged from 0.10212Vm-1 (0.02766 mWm-2) to 1.7334 Vm-1 (0.0079 Wm-2). The presence of devices was seen to increase the amount of radiation in the environment. The questionnaire results indicated that there was need to further educate the public on the effects of these radiations and precautionary to be adopted for safety.

scholarly journals Comparison of electric field strength and spatial distribution of electroconvulsive therapy and magnetic seizure therapy in a realistic human head model

2016 ◽  
Vol 36 ◽  
pp. 55-64 ◽  
Author(s):  
W.H. Lee ◽  
S.H. Lisanby ◽  
A.F. Laine ◽  
A.V. Peterchev
Keyword(s):  
Spatial Distribution ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Human Head ◽  
Neural Activation ◽  
Activation Threshold ◽  
Magnetic Seizure Therapy ◽  
Stimulus Current ◽  
The Brain

AbstractBackgroundThis study examines the strength and spatial distribution of the electric field induced in the brain by electroconvulsive therapy (ECT) and magnetic seizure therapy (MST).MethodsThe electric field induced by standard (bilateral, right unilateral, and bifrontal) and experimental (focal electrically administered seizure therapy and frontomedial) ECT electrode configurations as well as a circular MST coil configuration was simulated in an anatomically realistic finite element model of the human head. Maps of the electric field strength relative to an estimated neural activation threshold were used to evaluate the stimulation strength and focality in specific brain regions of interest for these ECT and MST paradigms and various stimulus current amplitudes.ResultsThe standard ECT configurations and current amplitude of 800–900 mA produced the strongest overall stimulation with median of 1.8–2.9 times neural activation threshold and more than 94% of the brain volume stimulated at suprathreshold level. All standard ECT electrode placements exposed the hippocampi to suprathreshold electric field, although there were differences across modalities with bilateral and right unilateral producing respectively the strongest and weakest hippocampal stimulation. MST stimulation is up to 9 times weaker compared to conventional ECT, resulting in direct activation of only 21% of the brain. Reducing the stimulus current amplitude can make ECT as focal as MST.ConclusionsThe relative differences in electric field strength may be a contributing factor for the cognitive sparing observed with right unilateral compared to bilateral ECT, and MST compared to right unilateral ECT. These simulations could help understand the mechanisms of seizure therapies and develop interventions with superior risk/benefit ratio.

scholarly journals GRANULATION OF RAW MATERIALS DURING THE DIELECTRIC HEATING PROCESS

2019 ◽  
Vol 14 (1) ◽  
pp. 94-99
Author(s):  
Юрий Крайнов ◽  
Yuriy Kraynov ◽  
Алексей Коробков ◽  
Aleksey Korobkov ◽  
Марьяна Белова ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Raw Materials ◽  
Point Of View ◽  
Heating Process ◽  
Electrodynamic System ◽  
Dielectric Heating ◽  
Gear Ring

The aim of the work is to develop and justify the parameters of the installation for the granulation of non-food waste of animal and vegetable origin in the process of dielectric heating. Objectives of the study: to develop microwave installations with volumetric resonators of different configurations, providing high electric field strength and continuity of the process of granulating raw materials; calculate the parameters of the electrodynamic system of the generator (electric field strength, the intrinsic Q factor of the resonator) and visualize the distribution pattern of the electromagnetic field in the resonators of different configurations. The studies were based on the dielectric heating theory and the theory of forming granules from multicomponent raw materials. The parameters of the electrodynamic system of the microwave generator were studied in the CST Microwave Studio program. The structural performance of volume resonators is analyzed from the point of view of the implementation of the requirements imposed by microwave devices and granulators intended for use in farms. Analyzed devices with a toroidal resonator and a disk matrix and with ellipsoid resonators and gear ring matrices are analyzed. The electromagnetic field distributions are visualized in the developed design versions of resonators combined with the working chamber of granulators. The values of the self-quality of the resonators and the electric field strength in them are calculated.

Optical Measurement of the Electric Field Strength in a Gel Insulator

2016 ◽  
Vol 136 (10) ◽  
pp. 1420-1421
Author(s):  
Yusuke Tanaka ◽  
Yuji Nagaoka ◽  
Hyeon-Gu Jeon ◽  
Masaharu Fujii ◽  
Haruo Ihori
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Optical Measurement

Effect of external magnetic field on lane formation in driven pair-ion plasmas

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Swati Baruah ◽  
U. Sarma ◽  
R. Ganesh
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Coupling Parameter ◽  
Critical Parameters ◽  
Coulomb Coupling ◽  
Lane Formation ◽  
Parameter Values

Lane formation dynamics in externally driven pair-ion plasma (PIP) particles is studied in the presence of external magnetic field using Langevin dynamics (LD) simulation. The phase diagram obtained distinguishing the no-lane and lane states is systematically determined from a study of various Coulomb coupling parameter values. A peculiar lane formation-disintegration parameter space is identified; lane formation area extended to a wide range of Coulomb coupling parameter values is observed before disappearing to a mixed phase. The different phases are identified by calculating the order parameter. This and the critical parameters are calculated directly from LD simulation. The critical electric field strength value above which the lanes are formed distinctly is obtained, and it is observed that in the presence of the external magnetic field, the PIP system requires a higher value of the electric field strength to enter into the lane formation state than that in the absence of the magnetic field. We further find out the critical value of electric field frequency beyond which the system exhibits a transition back to the disordered state and this critical frequency is found as an increasing function of the electric field strength in the presence of an external magnetic field. The movement of the lanes is also observed in a direction perpendicular to that of the applied electric and magnetic field directions, which reveals the existence of the electric field drift in the system under study. We also use an oblique force field as the external driving force, both in the presence and absence of the external magnetic field. The application of this oblique force changes the orientation of the lane structures for different applied oblique angle values.

scholarly journals Investigating the feasibility of cerebellar transcranial direct current stimulation to facilitate post-stroke overground gait performance in chronic stroke: a partial least-squares regression approach

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Dhaval Solanki ◽  
Zeynab Rezaee ◽  
Anirban Dutta ◽  
Uttama Lahiri
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Chronic Stroke ◽  
Least Squares Regression ◽  
Significance Level ◽  
Gait Performance ◽  
Wilcoxon Rank Sum Test ◽  
Gait Parameters ◽  
The Mean

Abstract Background Investigation of lobule-specific electric field effects of cerebellar transcranial direct current stimulation (ctDCS) on overground gait performance has not been performed, so this study aimed to investigate the feasibility of two lobule-specific bilateral ctDCS montages to facilitate overground walking in chronic stroke. Methods Ten chronic post-stroke male subjects participated in this repeated-measure single-blind crossover study, where we evaluated the single-session effects of two bilateral ctDCS montages that applied 2 mA via 3.14 cm2 disc electrodes for 15 min targeting (a) dentate nuclei (also, anterior and posterior lobes), and (b) lower-limb representations (lobules VIIb-IX). A two-sided Wilcoxon rank-sum test was performed at a 5% significance level on the percent normalized change measures in the overground gait performance. Partial least squares regression (PLSR) analysis was performed on the quantitative gait parameters as response variables to the mean lobular electric field strength as the predictors. Clinical assessments were performed with the Ten-Meter walk test (TMWT), Timed Up & Go (TUG), and the Berg Balance Scale based on minimal clinically important differences (MCID). Results The ctDCS montage specific effect was found significant using a two-sided Wilcoxon rank-sum test at a 5% significance level for 'Step Time Affected Leg' (p = 0.0257) and '%Stance Time Unaffected Leg' (p = 0.0376). The changes in the quantitative gait parameters were found to be correlated to the mean electric field strength in the lobules based on PLSR analysis (R2 statistic = 0.6574). Here, the mean electric field strength at the cerebellar lobules, Vermis VIIIb, Ipsi-lesional IX, Vermis IX, Ipsi-lesional X, had the most loading and were positively related to the 'Step Time Affected Leg' and '%Stance Time Unaffected Leg,' and negatively related to the '%Swing Time Unaffected Leg,' '%Single Support Time Affected Leg.' Clinical assessments found similar improvement in the TMWT (MCID: 0.10 m/s), TUG (MCID: 8 s), and BBS score (MCID: 12.5 points) for both the ctDCS montages. Conclusion Our feasibility study found an association between the lobular mean electric field strength and the changes in the quantitative gait parameters following a single ctDCS session in chronic stroke. Both the ctDCS montages improved the clinical outcome measures that should be investigated with a larger sample size for clinical validation. Trial registration: Being retrospectively registered.

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