scholarly journals Influence of a single lightning discharge on the intensity of an air electric field and acoustic emission of near-surface rocks

Solid Earth ◽  
2012 ◽  
Vol 3 (2) ◽  
pp. 307-311 ◽  
Author(s):  
S. E. Smirnov ◽  
Y. V. Marapulets
Keyword(s):  
Acoustic Emission ◽  
Electric Field ◽  
Normal Level ◽  
Electric Potential ◽  
Characteristic Time ◽  
Lightning Discharge ◽  
Potential Gradient ◽  
Capacitor Discharge ◽  
Near Surface ◽  
Sharp Fall

Abstract. The effect was observed as a sharp fall of the electric potential gradient from +80 V m−1 down to –21 V m−1. After that the field returned to its normal level according to the formula of the capacitor discharge with 17 s characteristic time. Simultaneously, the response of the acoustic emission of surface rocks in the range of frequencies between 6.5 kHz and 11 kHz was evaluated.

scholarly journals Influence of a single lightning on the intensity of an air electric field and acoustic emission of near surface rocks

2012 ◽  
Vol 4 (1) ◽  
pp. 627-640
Author(s):  
S. E. Smirnov ◽  
Y. V. Marapulets
Keyword(s):  
Acoustic Emission ◽  
Electric Field ◽  
Characteristic Time ◽  
Electric Field Intensity ◽  
Lightning Discharge ◽  
Field Potential ◽  
Potential Gradient ◽  
Frequency Range ◽  
Near Surface ◽  
Electric Field Potential

Abstract. The effect of a single lightning discharge on electric field intensity in the near ground atmosphere was investigated. The effect appeared as a sharp fall of electric field potential gradient from 80 V m−1 up to −21 V m−1. The process of intensity recovery is described by flat capacitor model with characteristic time of recovery of 17 c. Simultaneously with electric field, the acoustic emission response in the near surface rocks on lightning discharge was registered in the frequency range of 6.5–11 kHz.

scholarly journals Revisiting the long-term decreasing trend of atmospheric electric potential gradient measured at Nagycenk, Hungary, Central Europe

2021 ◽  
Vol 39 (4) ◽  
pp. 627-640
Author(s):  
Attila Buzás ◽  
Veronika Barta ◽  
Tamás Horváth ◽  
József Bór
Keyword(s):  
Time Series ◽  
Electric Field ◽  
Central Europe ◽  
Electric Potential ◽  
Potential Gradient ◽  
Time Dependent ◽  
Shielding Effect ◽  
Term Variation ◽  
Atmospheric Electric Potential Gradient

Abstract. In 2003, a decreasing trend was reported in the long-term (1962–2001) fair weather atmospheric electric potential gradient (PG) measured in the Széchenyi István Geophysical Observatory (NCK; 47∘38′ N, 16∘43′ E), Hungary, Central Europe. The origin of this reduction has been the subject of a long-standing debate, due to a group of trees near the measurement site which reached significant height since the measurements have started. Those trees have contributed to the lowering of the ambient vertical electric field due to their electrostatic shielding effect. In the present study, we attempt to reconstruct the true long-term variation of the vertical atmospheric electric field at NCK. The time-dependent shielding effect of trees at the measurement site was calculated to remove the corresponding bias from the recorded time series. A numerical model based on electrostatic theory was set up to take into account the electrostatic shielding of the local environment. The validity of the model was verified by on-site measurement campaigns. The changing height of the trees between 1962 and 2017 was derived from national-average age–height diagrams for each year. Modelling the time-dependent electrical shielding effect of the trees at NCK revealed that local effects played a pivotal role in the long-term decrease. The results suggest that earlier attempts could not quantify the shielding effect of the trees at NCK accurately. In this work it is found that the reconstructed PG time series at NCK exhibits an increase between 1962 and 1997 followed by a decaying trend since 1997. It is pointed out that long-term variation in summertime and wintertime PG averages should be analysed separately as these may contribute to trends in the annual mean values rather differently.

Removal of heavy metal from soil and groundwater by in-situ electrokinetic remediation

2000 ◽  
Vol 42 (7-8) ◽  
pp. 335-343 ◽  
Author(s):  
S. Shiba ◽  
S. Hino ◽  
Y. Hirata ◽  
T. Seno
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Electric Potential ◽  
Potential Gradient ◽  
Electrokinetic Remediation ◽  
Contaminated Aquifer ◽  
Physico Chemical ◽  
Operational Variables ◽  
Mass Transport Process

The operational variables of electrokinetic remediation have not been cleared yet, because this method is relatively new and is an innovative technique in the aquifer remediation. In order to investigate the operational variables of the electrokinetic remediation, a mathematical model has been constructed based on the physico chemical mass transport process of heavy metals in pore water of contaminated aquifer. The transport of the heavy metals is driven not only by the hydraulic flow due to the injection of the purge water but also by the electromigration due to the application of the electric potential gradient. The electric potential between anode and cathode is the important operational variable for the electrokinetic remediation. From the numerical simulations with use of this model it is confirmed that the remediation starts from the up stream anode and gradually the heavy metal is transported to the down stream cathode and drawn out through the purge water.

scholarly journals Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

2012 ◽  
Vol 30 (1) ◽  
pp. 49-56 ◽  
Author(s):  
M. Yamauchi ◽  
M. Takeda ◽  
M. Makino ◽  
T. Owada ◽  
I. Miyagi
Keyword(s):  
Electric Field ◽  
Nuclear Power ◽  
Potential Gradient ◽  
Radioactive Material ◽  
Strong Wind ◽  
Fair Weather ◽  
Large Area ◽  
Radiation Dose Rate ◽  
Radioactive Dust ◽  
Cloudy Weather

Abstract. Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14–15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50 V m−1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16–20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20–22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface.

Some simple theorems concerning crystal lattice sums of electric potential, electric field, and electric field gradient in crystals

1967 ◽  
Vol 20 (12) ◽  
pp. 2551 ◽  
Author(s):  
CK Coogan
Keyword(s):  
Electric Field ◽  
Field Gradient ◽  
Electric Potential ◽  
Higher Symmetry ◽  
Lattice Sums ◽  
Symmetry Properties ◽  
Lattice Sum ◽  
Direct Lattice ◽  
Electric Potential Field ◽  
Conver Gence

The conditions under which direct lattice sums of electric potential, field, and field gradient converge are discussed. The analogous conditions under which differences in these lattice sums, for two points in the crystal, converge are also outlined. These conditions are applied to direct lattice sum calculations in crystals in which the ideal lattice is distorted close to a defect of some kind. The conver- gence conditions are then applied to the case of determining the direct lattice sums in crystals in which higher symmetry properties can be invoked, which leads to a knowledge by inspection of the lattice sum at one point in the unit cell.

scholarly journals Electric potential differences across auroral generator interfaces

2013 ◽  
Vol 31 (2) ◽  
pp. 251-261 ◽  
Author(s):  
J. De Keyser ◽  
M. Echim
Keyword(s):  
Electric Field ◽  
High Altitude ◽  
Electric Fields ◽  
Electric Potential ◽  
Equilibrium Configuration ◽  
Potential Difference ◽  
Field Profile ◽  
Electric Potential Difference ◽  
Electric Field Profile

Abstract. Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

Cause-and-effect relations between cosmic rays, electric field, aerosols and clouds

2021 ◽  
Author(s):  
Stavros Stathopoulos ◽  
Stergios Misios ◽  
Konstantinos Kourtidis
Keyword(s):  
Cosmic Rays ◽  
Electric Field ◽  
Causal Effect ◽  
Atmospheric Electricity ◽  
Potential Gradient ◽  
Galactic Cosmic Rays ◽  
The European Union ◽  
Development Education ◽  
Cause And Effect ◽  
Global Coordination

<p>Here we examine the cause-and-effect relations between galactic cosmic rays, electric field, aerosols and clouds over a region of Atlantic Ocean, during a Forbush Decrease (FD) event on 07/12/2015, using Convergent Cross Mapping (CCM) method. For this purpose, we used FD data from the Neuron Monitor Database (NMDB), Potential Gradient data (PG) from Global Coordination of Atmospheric Electricity Measurements (GLOCAEM) and remote sensing data from MODIS/Aqua, namely Aerosol Optical Depth at 550nm (AOD), Cloud Fraction (CF), Cloud Optical Thickness (COT), Cloud Top Pressure (CTP), Cirrus Reflectance (CR) and Cloud Effective Radius-Liquid (CERL). A cause-and-effect relation was found between FD and AOD, CERL, CF and PG, over the region. On the other hand, no causal effect was found between FD and COT, CTP and CR. This research is funded in the context of the project "Cosmic and electric effects on aerosols and clouds” (MIS: 5049552) under the call for proposals “Support for researchers with emphasis on young researchers - Cycle B” (EDULL 103). The project is co-financed by Greece and the European Union (European Social Fund - ESF) by the Operational Programme Human Resources Development, Education and Lifelong Learning 2014-2020.</p>

Variations of the electric field and current in the near-surface atmosphere during magnetic storms

2021 ◽  
Author(s):  
Svetlana A. Riabova ◽  
Yaroslav O. Romanovsky ◽  
Alexander A. Spivak
Keyword(s):  
Electric Field ◽  
Magnetic Storms ◽  
Near Surface ◽  
Surface Atmosphere

Deepening of domains at e-beam writing on the -Z surface of lithium niobate

2021 ◽  
Author(s):  
Lyudmila Kokhanchik ◽  
Evgenii Emelin ◽  
Vadim Vladimirovch Sirotkin ◽  
Alexander Svintsov
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Lithium Niobate ◽  
Electric Field ◽  
Domain Walls ◽  
Normal Component ◽  
Beam Current ◽  
Near Surface ◽  
Domain Structures ◽  
Sign Inversion

Abstract The focus of the study was to investigate the peculiarities of the domains created by electron beam (e-beam) in a surface layer of congruent lithium niobate, which comparable to a depth of electron beam charge penetration. Direct e-beam writing (DEBW) of different domain structures with a scanning electron microscope was performed on the polar -Z cut. Accelerating voltage 15 kV and e-beam current 100 pA were applied. Different patterns of local irradiated squares were used to create domain structures and single domains. No domain contrast was observed by the PFM technique. Based on chemical etching, it was found that the vertices of the domains created do not reach the surface level. The average deepening of the domain vertices was several hundred nanometers and varied depending on the irradiation dose and the location of the irradiated areas (squares) relative to each other. Computer simulation was applied to analyze the spatial distribution of the electric field in the various irradiated patterns. The deepening was explained by the fact that in the near-surface layer there is a sign inversion of the normal component of the electric field strength vector, which controls the domain formation during DEBW. Thus, with the help of e-beam, domains were created completely located in the bulk, in contrast to the domains that are nucleated on the surface of the -Z cut during the polarization inversion with AFM tip. The detected deepening of e-beam domains suggests the possibility of creating the “head-to-head” domain walls in the near-surface layer lithium niobate by DEBW.

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