Estimating the electrical conductivity of clayey soils with varying mineralogy using the index properties of soils

2022 ◽  
Vol 217 ◽  
pp. 106388
Hyunwook Choo ◽  
Junghee Park ◽  
Thu Thi Do ◽  
Changho Lee
Agropedology ◽  
2019 ◽  
Vol 27 (2) ◽  
Yagani Sinha ◽  
Rajeev Srivastava ◽  
Jagdish Prasad ◽  
M.S.S. Nagaraju ◽  

Soil salinity is a major environmental hazard which adversely affects plant growth, crop production, soil and water quality and agricultural productivity.Soil salinity is determined by measuring electrical conductivity of soil water suspension. Though saturation paste ECe closely relates with plant growth and development but its measurement is laborious and time-consuming specifically in clayey soils when large number of samples are analyzed. Measurement of EC1:2 (1:2 Soil: water suspension) is very quick and economical. Therefore, a need is felt to develop a relationship between ECe and EC1:2so that the values of EC1:2 could easily be related to ECe. For this, anexperiment was conducted on four soil series representing swell-shrink soils. Soils were artificially salinized with solutions (salt) of 0.2, 0.5, 1 and 2% of chloride salts (NaCl, CaCl2, MgCl2 and their mixture) and replicated three times. The results indicate that a significant relationship (r=0.96) exists between ECe and soil EC1:2and soil ECe can be reliably predicted from EC1:2 in swell-shrink soils.

Horst G. Brandes

Permeability values for a range of fine-grained deep-sea sediments are presented and evaluated in terms of index properties such as plasticity, grain size and carbonate content. It is found that whereas clay-rich sediments have similar permeabilities to those of equivalent land-based fine-grained soils, the presence of volcanic, carbonate and other non-clay fractions tends to increase permeability somewhat. Volcanic silty-clayey soils from Hawaii have comparable permeability values, although they can be slightly more permeable.

John C. Russ ◽  
Nicholas C. Barbi

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Klaus-Ruediger Peters ◽  
Samuel A. Green

High magnification imaging of macromolecules on metal coated biological specimens is limited only by wet preparation procedures since recently obtained instrumental resolution allows visualization of topographic structures as smal l as 1-2 nm. Details of such dimensions may be visualized if continuous metal films with a thickness of 2 nm or less are applied. Such thin films give sufficient contrast in TEM as well as in SEM (SE-I image mode). The requisite increase in electrical conductivity for SEM of biological specimens is achieved through the use of ligand mediated wet osmiuum impregnation of the specimen before critical point (CP) drying. A commonly used ligand is thiocarbohvdrazide (TCH), first introduced to TEM for en block staining of lipids and glvcomacromolecules with osmium black. Now TCH is also used for SEM. However, after ligand mediated osinification nonspecific osmium black precipitates were often found obscuring surface details with large diffuse aggregates or with dense particular deposits, 2-20 nm in size. Thus, only low magnification work was considered possible after TCH appl ication.

1991 ◽  
Vol 18 (3) ◽  
pp. 611-627 ◽  
Marta L. Fiorotto ◽  
William J. Klish

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

1980 ◽  
Vol 41 (C5) ◽  
pp. C5-219-C5-222
J. P. Desfours ◽  
C. Godart ◽  
J. P. Nadai ◽  
A. Mauger ◽  
G. Weill ◽  

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