Mapping of induced polarization using natural fields

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Erika Gasperikova ◽  
H. Frank Morrison
Keyword(s):  
Electric Field ◽  
Surrounding Medium ◽  
Low Frequency ◽  
Induced Polarization ◽  
The Body ◽  
Electromagnetic Response ◽  
Frequency Dependent ◽  
Finite Body ◽  
Electric Field Profile ◽  
Measured Response

The observed electromagnetic response of a finite body is caused by induction and polarization currents in the body and by the distortion of the induction currents in the surrounding medium. At a sufficiently low frequency, there is negligible induction and the measured response is that of the body distorting the background currents just as it would distort a direct current (dc). Because this dc response is not inherently frequency dependent, any observed change in response of the body for frequencies low enough to be in this dc limit must result from frequency‐dependent conductivity. Profiles of low‐frequency natural electric (telluric) fields have spatial anomalies over finite bodies of fixed conductivity that are independent of frequency and have no associated phase anomaly. If the body is polarizable, the electric field profile over the body becomes frequency dependent and phase shifted with respect to a reference field. The technique was tested on data acquired in a standard continuous profiling magnetotelluric (MT) survey over a strong induced polarization (IP) anomaly previously mapped with a conventional pole‐dipole IP survey. The extracted IP response appears in both the apparent resistivity and the normalized electric field profiles.

scholarly journals BEM Modelling of High Voltage ELF electric field applied to a 3D pregnant woman model

2010 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Cristina Peratta ◽  
Andres Peratta ◽  
Dragan Poljak
Keyword(s):  
Pregnant Woman ◽  
Electric Field ◽  
Electric Fields ◽  
High Voltage ◽  
Medical Information ◽  
Three Dimensional ◽  
Low Frequency ◽  
Element Model ◽  
The Body ◽  
Geometrical Properties

The paper introduces a three dimensional multidomainboundary element model of a pregnant woman and foetus for the analysis of exposure to high voltage extremely low frequency electric fields. The definition of the differentphysical and geometrical properties of the relevant tissues is established according to medical information available in existing literature. The model takes into account changes in geometry, body mass, body fat, and overall chemical composition in the body which influence the electrical properties, throughout the different gestational periods. The developed model is used to solve the case of exposure to overhead power transmission lines at different stages of pregnancy including weeks 8, 13, 26 and 38. The results obtained are in line with those published in the earlier works considering different approaches. In addition, a sensitivity analysis involving varying scenarios of conductivity, foetus postures and geometry for each stage is defined and solved. Finally, a correlation between the externally applied electric field and the current density inside the foetus is established and the zones of maximum exposure are identified.

THE EFFECT OF LOW FREQUENCY ELECTROMAGNETIC RADIATION ON THE MORPHOLOGY OF DENTAL AND PERIODONTAL TISSUES (EXPERIMENTAL INVESTIGATION)

2019 ◽  
Vol 72 (5) ◽  
pp. 773-778
Author(s):  
Iryna V. Markovskaya
Keyword(s):  
Electric Field ◽  
Electromagnetic Radiation ◽  
Low Frequency ◽  
Histochemical Staining ◽  
The Body ◽  
Morphometric Study ◽  
Control Group ◽  
High Biological Activity ◽  
Periodontal Tissues ◽  
Alternating Electric Field

Introduction: Low intensity electromagnetic effects possess a high biological activity, reduce the adaptive reserves of the body, impair immunity, adversely affect the functional state of the organs and body systems. The aim of the study was to identify in the experiment the effect of low-frequency electromagnetic radiation on the morphological state of the dental and periodontal tissue. Materials and methods: The experiment was conducted on WAG rats weighing 180–200 g, during which two groups were formed: group 1 (control group) included 12 WAG rats, which were not performed any manipulations; the rats of group 2 (investigation group) (n=12) for 30 days were exposed to a 70 kHz low-frequency alternating electric field (5th frequency range) daily from 9.00 to 12.00. To simulate a low-frequency 70 kHz alternating electric field, certified experimental equipment was used. The study material was the upper jaw tissue. Histological and histochemical staining methods were used. Morphometric study was conducted. Results: Complex morphological study on the experimental material allowed identifying the damaging effect of low-frequency electromagnetic radiation on the structural components of tooth and periodontal tissues. Conclusions: Our findings suggest that the workers who are exposed to occupational low-frequency electromagnetic radiation should be included in the risk group for developing diseases of the dentomandibular system in order to carry out timely therapeutic and preventive measures.

scholarly journals An Efficient Deterministic-Stochastic Model of the Human Body Exposed to ELF Electric Field

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Anna Šušnjara ◽  
Dragan Poljak
Keyword(s):  
Electric Field ◽  
Stochastic Model ◽  
Human Body ◽  
Low Frequency ◽  
Stochastic Approach ◽  
Axial Current ◽  
The Body ◽  
Cylindrical Antenna ◽  
New Perspective ◽  
Mean Trend

The paper deals with the deterministic-stochastic model of the human body represented as cylindrical antenna illuminated by a low frequency electric field. Both analytical and numerical (Galerkin-Bubnov scheme of Boundary Element Method) deterministic solutions of the problem are outlined. This contribution introduces the new perspective of the problem: the variability inherent to input parameters, such as the height of the body, the shape of the body, and the conductivity of body tissue, is propagated to the output of interest (induced axial current). The stochastic approach is based on the stochastic collocation (SC) method. Computational examples show the mean trend of both analytically and numerically computed axial current with the confidence margins for different set of input random variables. The results point out the possibility of improving the efficiency in calculation of basic restriction parameter values in electromagnetic dosimetry.

scholarly journals Effect of Geometrical Properties on Localized Surface Plasmon Resonance of Gold Nanoparticles

2021 ◽  
Vol 31 (4) ◽  
Author(s):  
Luong Lam Nguyen ◽  
Quoc Trung Trinh ◽  
Quang Bao Tu ◽  
Van Quynh Nguyen ◽  
Thi Hong Cam Hoang
Keyword(s):  
Gold Nanoparticles ◽  
Surface Plasmon Resonance ◽  
Electric Field ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Surrounding Medium ◽  
Localized Surface Plasmon ◽  
Geometrical Properties ◽  
Electric Field Profile

This work reportson plasmonic effects (i.e light scattering and absorption properties) induced by two different gold nanoparticles (AuNPs)-shaped: spherical particle and triangular particle. The scattering cross-section and electric field profiles have been investigated by using theboundary element method (MNPBEM toolbox). Two configurations: the isolated AuNPand the coupledtwo-gold NPsystem have been considered to evaluate the localized surface plasmon resonance (LSPR) in eithersingle or coupled AuNPstructures. The effect of the surrounding medium on the scattering behavior of the NPs has also been examined. Then the dependence of “hotspot” intensity on the distance between two NPs has been recognized by mapping the electric field profile. The obtained results can be used as the guidelines for synthesizing AuNP structures to employ LSPR for sensing or other applications.

Development of a Low Frequency Electric Field Probe Integrating Data Acquisition and Storage

2020 ◽  
Vol E103.C (8) ◽  
pp. 345-352
Author(s):  
Zhongyuan ZHOU ◽  
Mingjie SHENG ◽  
Peng LI ◽  
Peng HU ◽  
Qi ZHOU
Keyword(s):  
Electric Field ◽  
Data Acquisition ◽  
Low Frequency ◽  
Frequency Electric Field ◽  
Electric Field Probe ◽  
And Storage

PEMANFAATAN RADIASI ENERGI TEGANGAN 150 KV UNTUK LAMPU LED PENERANGAN JALAN

Jurnal Teknik ◽  
2018 ◽  
Vol 7 (1) ◽  
Author(s):  
Mauludi Manfaluthy
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
High Voltage ◽  
Low Frequency ◽  
Energy Utilization ◽  
World Health ◽  
Electromagnetic Signals ◽  
Health Organization ◽  
The Magnetic Field ◽  
Low Frequency Waves

WHO (World Health Organization) concludes that not much effect is caused by electric field up to 20 kV / m in humans. WHO standard also mentions that humans will not be affected by the magnetic field under  100 micro tesla and that the electric field will affect the human body with a maximum standard of 5,000 volts per meter. In this study did not discuss about the effect of high voltage radiation SUTT (High Voltage Air Channel) with human health. The research will focus on energy utilization of SUTT radiation. The combination of electric field and magnetic field on SUTT (70-150KV) can generate electromagnetic (EM) and radiation waves, which are expected to be converted to turn on street lights around the location of high voltage areas or into other forms. The design of this prototype works like an antenna in general that captures electromagnetic signals and converts them into AC waves. With a capacitor that can store the potential energy of AC and Schottky diode waves created specifically for low frequency waves, make the current into one direction (DC). From the research results obtained the current generated from the radiation is very small even though the voltage is big enough.Keywords : Radiance Energy, Joule Thief, and  LED Module.

Electric-field profile and current control of a long epitaxial GaAs n layer

1972 ◽  
Vol 8 (4) ◽  
pp. 93 ◽  
Author(s):  
G.A. Swartz ◽  
A. Gonzalez ◽  
A. Dreeben
Keyword(s):  
Electric Field ◽  
Current Control ◽  
Field Profile ◽  
Epitaxial Gaas ◽  
Electric Field Profile

scholarly journals Strong Waves from Pulsars and Morphologies in SNRs

1983 ◽  
Vol 101 ◽  
pp. 499-501
Author(s):  
Gregory Benford ◽  
Attilio Ferrari ◽  
Silvano Massaglia
Keyword(s):  
Large Amplitude ◽  
Crab Nebula ◽  
Surrounding Medium ◽  
Low Frequency ◽  
Optical Emission ◽  
Amplitude Wave ◽  
Surface Magnetic Field ◽  
Plasma Absorption ◽  
The Crab Nebula ◽  
Large Amplitude Wave

Canonical models for pulsars predict the emission of low–frequency waves of large amplitudes, produced by the rotation of a neutron star possessing a strong surface magnetic field. Pacini (1968) proposed this as the basic drain which yields to the pulsar slowing–down rate. The main relevance of the large amplitude wave (LAW) is the energetic link it provides between the pulsar and the surrounding medium. This role has been differently emphasized (Rees and Gunn, 1974; Ferrari, 1974), referring to absorption effects by relativistic particle acceleration and thermal heating, either close to the pulsar magnetosphere or in the nebula. It has been analyzed in the special case of the Crab Nebula, where observations are especially rich (Rees, 1971). As the Crab Nebula displays a cavity around the pulsar of dimension ∼1017cm, the function of the wave in sweeping dense gas away from the circumpulsar region is widely accepted. Absorption probably occurs at the inner edges of the nebula; i.e., where the wave pressure and the nebular pressure come into balance. Ferrari (1974) interpreted the wisps of the Crab Nebula as the region where plasma absorption occurs, damping the large amplitude wave and driving “parametric” plasma turbulence, thus trasferring energy to optical radiation powering the nebula. The mechanism has been extended to interpret the specific features of the “wisps” emission (Benford et al., 1978). Possibly the wave fills the nebula completely, permeating the space outside filaments with electromagnetic energy, continuously accelerating electrons for the extended radio and optical emission (Rees, 1971).

scholarly journals Slithering CSF: Cerebrospinal Fluid Dynamics in the Stationary and Moving Viper Boa, Candoia aspera

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 672
Author(s):  
Bruce A. Young ◽  
Skye Greer ◽  
Michael Cramberg
Keyword(s):  
Cerebrospinal Fluid ◽  
Cardiac Cycle ◽  
Low Frequency ◽  
Mean Amplitude ◽  
The Body ◽  
Body Waves ◽  
Lower Amplitude ◽  
Lateral Undulation ◽  
Recovery From Anesthesia ◽  
The Relationship

In the viper boa (Candoia aspera), the cerebrospinal fluid (CSF) shows two stable overlapping patterns of pulsations: low-frequency (0.08 Hz) pulses with a mean amplitude of 4.1 mmHg that correspond to the ventilatory cycle, and higher-frequency (0.66 Hz) pulses with a mean amplitude of 1.2 mmHg that correspond to the cardiac cycle. Manual oscillations of anesthetized C. aspera induced propagating sinusoidal body waves. These waves resulted in a different pattern of CSF pulsations with frequencies corresponding to the displacement frequency of the body and with amplitudes greater than those of the cardiac or ventilatory cycles. After recovery from anesthesia, the snakes moved independently using lateral undulation and concertina locomotion. The episodes of lateral undulation produced similar influences on the CSF pressure as were observed during the manual oscillations, though the induced CSF pulsations were of lower amplitude during lateral undulation. No impact on the CSF was found while C. aspera was performing concertina locomotion. The relationship between the propagation of the body and the CSF pulsations suggests that the body movements produce an impulse on the spinal CSF.

scholarly journals Plasma-surface interaction: dielectric and metallic targets and their influence on the electric field profile in a kHz AC-driven He plasma jet

2019 ◽  
Vol 28 (4) ◽  
pp. 045003 ◽  
Author(s):  
A Sobota ◽  
O Guaitella ◽  
G B Sretenović ◽  
V V Kovačević ◽  
E Slikboer ◽  
...  
Keyword(s):  
Electric Field ◽  
Plasma Jet ◽  
Surface Interaction ◽  
Field Profile ◽  
Plasma Surface ◽  
Electric Field Profile
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