Electrode effect at a mountain station

The present study was conducted in Salt marshes and Salt pans in central parts of Iran. 121 specimens of ants were collected by trapping and hand during spring, summer and autumn 2017 to 2019. Nine species belong to two subfamilies of Myrmicinae and Formicinae were identified. The vegetation, physical and chemical parameters of soil such as salinity, Ph, and other factors were investigated. Darband Shoor Mountain station with five species had the highest diversity and vegetation density and the lowest salinity of soil (72.14 ds/m) whereas Salt Lake station had only one species, with no vegetation and the highest salinity of soil (153.15 ds/m). Cataglyphis lividus (André, 1881) was the dominant species in all the stations except in Darband Shoor Mountain station. All the species were reported for the first time from salt marshes and salt pans in the central parts of Iran and were approved by Prof. Brian Taylor, in Royal Entomological Society of London, England.

Download Full-text

Electrical studies on the doping dependence and electrode effect of metal–PANI–metal structures

Journal of Physics D Applied Physics ◽

10.1088/0022-3727/38/9/017 ◽

2005 ◽

Vol 38 (9) ◽

pp. 1437-1443 ◽

Cited By ~ 25

Author(s):

R F Bianchi ◽

H N da Cunha ◽

R M Faria ◽

G F Leal Ferreira ◽

J Mariz G Neto

Keyword(s):

Metal Structures ◽

Doping Dependence ◽

Electrode Effect ◽

Electrical Studies

Download Full-text

Electrode effect measurements above the sea

Journal of Atmospheric and Terrestrial Physics ◽

10.1016/0021-9169(61)90101-5 ◽

1961 ◽

Vol 20 (1) ◽

pp. 79-81 ◽

Cited By ~ 29

Author(s):

R. Mühleisen

Keyword(s):

Electrode Effect

Download Full-text

On the effect of electrode finiteness in small-scale electrical resistivity imaging

Geophysics ◽

10.1190/geo2018-0074.1 ◽

2018 ◽

Vol 83 (6) ◽

pp. EN39-EN52 ◽

Cited By ~ 2

Author(s):

Cécile Verdet ◽

Yannick Anguy ◽

Colette Sirieix ◽

Rémi Clément ◽

Cécile Gaborieau

Keyword(s):

Electrical Resistivity ◽

Point Source ◽

Cell Model ◽

Characteristic Size ◽

Electrode Spacing ◽

Small Scale ◽

Electrode Effect ◽

Point Approximation ◽

Electrode Length ◽

The Impact

Electrical resistivity tomography (ERT) profiles including finite steel-rod electrodes have been widely used in assuming a surface-node current injection for inversion. This hypothesis was shown by others to be safe for ratios of electrode embedment to electrode spacing smaller than 20%. Relying on the conductive cell model (CCM), we took into account the complete electrodes in the DC forward problem. We found that an electrode effect is included in resistivity sections inverted with a surface point electrode model. Several synthetic examples indicated that this unwanted effect is particularly developed when the electrode spacing does not meet a double constraint from the characteristic size of a shallow heterogeneity and from the electrode embedment. This effect deserved correction. A point approximation for a finite electrode referred to as the equivalent electrode point (EEP) was sought by placing a point-source current in the ground along the electrode length. The appropriate EEP depth was the one for which the CCM and a buried point source minimized a systematic geometric error; i.e., the relative change of the geometric factors obtained with the CCM and with an EEP. An EEP placed at 73% of the electrode length was declared as a suitable point approximation for an electrode. Use of this point assumption for inversion remedied efficiently the electrode effect subject to conditions. More precisely, the electrode spacing should stay within a lower bound equal to twice the electrode embedment and an upper bound equal to the shallow heterogeneity characteristic size divided by 0.75. The interest of such a metrological appraisal of the suitable acquisition layout to be used on the field was illustrated by a small-scale ERT field survey. This case study permitted us to understand more reliably the impact from fires upon a centimetric shallow layer in a calcareous wall.

Download Full-text