scholarly journals To the method of studying the permittivity of soils (on an example of soils of ravine forests of the northern variant of the steppe zone of Ukraine)

2016 ◽  
Vol 17 (3-4) ◽  
pp. 90-97
Author(s):  
V. A. Gorban
Keyword(s):  
Dielectric Permittivity ◽  
Soil Sample ◽  
Solid Phase ◽  
Clay Fraction ◽  
Dielectric Permeability ◽  
Steppe Zone ◽  
Electrophysical Characteristic ◽  
Soil Particles ◽  
Soil Fractions ◽  
Soil Fraction

The article is devoted to the establishment of the peculiarities of the method for studying the dielectric permittivity of soils, which is its important electrophysical characteristic. The dielectric permittivity of the soil, which is a complex multiphase medium, depends on the dielectric properties of the mineral composition of its solid phase, the chemical composition, structure and composition of soil particles, their shape and size, and also the dielectric features of inter-porous air and moisture. Now it is possible to greatly simplify the technique of measuring the dielectric permittivity of soils due to the wide dissemination of compact digital instruments that provide high accuracy in measuring the capacitive characteristics of various media. For the approbation of the method, samples of soils of ravine forests of the northern variant of the steppe zone of Ukraine were used, as well as individual soil fractions of 2–3, 1–2 and 0.5–1 mm. All samples were studied in an air-dry state to level out the effect of moisture on the dielectric permittivity of soils, as described in many scientific papers. For measurements, a cylindrical condenser made of organic glass was manufactured, which does not conduct an electric current. The diameter of the capacitor plates was 20 mm, the distance between them was 0.7 mm. After placing the sample in the condenser, it was sealed by pressure from above the weight of about 0.3 kg to create a better contact with the covers of the capacitor. The measurements were carried out using a digital capacitance meter CM-9601A in the range of 0.1–200 picofarads at a test frequency of 800 Hz. At the end of the measurement, the soil sample was weighed to calculate its density. All measurements were performed three times. As a result of using this technique, it was found that the permittivity of a general soil sample is generally higher than that of individual soil fractions. This is explained by the more compact placement of soil particles in the soil sample and its greater density, while in studies of individual fractions, due to their shape, there remain pores between the aggregates that are not filled with soil material, which cause a decrease in sample density. As a result, the maximum density is typical for the soil fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This is due to the fact that the maximum permittivity, as a rule, is characteristic for the fraction 0.5–1 mm, and the minimum for the fraction 2–3 mm. This assertion was proved by the measurements carried out. It was also found that the value of dielectric permittivity is significantly affected by soil enrichment of the clay fraction, the increased content of which causes an increase in the dielectric permittivity. Thus, as a result of the research, a method for measuring the dielectric permittivity of soils was tested using a modern digital capacitive meter. An increase in the dielectric permittivity of soils with an increase in their density and an increase in the content of the clay fraction was established. Soils, in general, have an increased permittivity in comparison with soil fractions of 2–3, 1–2 and 0.5–1 mm. There was a need to develop and approbate a technique for measuring the dielectric permittivity of soils in the field using undisturbed addition samples. In the future, in complex studies of soils, it is also desirable to perform a measurement of their dielectric permeability.

scholarly journals Effect of Bovine Manure on Fecal Coliform Attachment to Soil and Soil Particles of Different Sizes

2007 ◽  
Vol 73 (10) ◽  
pp. 3363-3370 ◽  
Author(s):  
Andrey K. Guber ◽  
Yakov A. Pachepsky ◽  
Daniel R. Shelton ◽  
Olivia Yu
Keyword(s):  
Clay Fraction ◽  
Free Cell ◽  
Organic Coating ◽  
Bacterial Attachment ◽  
Fecal Coliforms ◽  
Clay Particles ◽  
Soil Particles ◽  
Soil Fractions ◽  
Sand Particles ◽  
Coated Sand

ABSTRACT Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt fraction, and the clay fraction of loam and sandy clay loam soils were separated and used along with soil samples in batch attachment experiments with water-FC suspensions and water-manure-FC suspensions. In the absence of manure colloids, bacterial attachment to soil, silt, and clay particles was much higher than the attachment to sand particles having no organic coating. The attachment to the coated sand particles was similar to the attachment to silt and clay. Manure colloids in suspensions decreased bacterial attachment to soils, clay and silt fractions, and coated sand fractions, but did not decrease the attachment to sand fractions without the coating. The low attachment of bacteria to silt and clay particles in the presence of manure colloids may cause predominantly free-cell transport of manure-borne FC in runoff.

scholarly journals Chemical and Spectroscopic Investigation of Different Soil Fractions as Affected by Soil Management

2020 ◽  
Vol 10 (7) ◽  
pp. 2571 ◽  
Author(s):  
Francesco De Mastro ◽  
Claudio Cocozza ◽  
Gennaro Brunetti ◽  
Andreina Traversa
Keyword(s):  
Diffuse Reflectance ◽  
Soil Depth ◽  
Soil Layer ◽  
Mineralogical Composition ◽  
Coarse Fraction ◽  
Soil Fractions ◽  
Soil Fraction ◽  
Drift Analysis ◽  
Diffuse Reflectance Infrared ◽  
Conventional Ct

The interaction of organic matter with the finest soil fractions (<20 μm) represents a good way for its stabilization. This study investigates the effects of conventional (CT), minimum (MT), and no (NT) tillage, fertilization, and non-fertilization, and soil depth (0–30, 30–60, and 60–90 cm) on the amount of organic carbon (OC) in four soil fractions. Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) was performed to obtain information about the OC quality and the mineralogical composition of these fractions. The CT shows the highest amount of the finest fraction while the fertilization enhances the microbial community with the increase of soil micro-aggregates (250–53 μm). The coarse fraction (>250 μm) is highest in the upper soil layer, while the finest fraction is in the deepest one. The greatest OC content is observed in the topsoil layer and in the finest soil fraction. DRIFT analysis suggests that organic components are more present in the finest fraction, calcite is mainly localized in the coarse fraction, quartz is in micro-aggregates and 53–20 μm fraction, and clay minerals are in the finest fraction.

Loss involved by igniting soil fractions during the mechanical analysis of soils

1928 ◽  
Vol 18 (1) ◽  
pp. 123-130
Author(s):  
F. J. Martin
Keyword(s):  
Organic Matter ◽  
Clay Fraction ◽  
Tropical Soils ◽  
Mechanical Analysis ◽  
Lateritic Soils ◽  
Soil Fractions ◽  
Silica Alumina ◽  
Silica Alumina Ratio

1. Examinations have been made of the losses involved by igniting fractions of tropical soils.2. It has been found that these losses are partly due to organic matter and partly to combined water; the greater part of the loss is due to water.3. In the clay fraction there is a correlation between the amount of combined water and the silica/alumina ratio; the greater the ratio the less the combined water. This is affected by the proportion of iron present.4. Lateritic soils lose more water on ignition than other soils but the lateritic material in soils is not necessarily evenly distributed throughout the fractions; those fractions containing the highest proportions of lateritic material lose the most water.

scholarly journals Nanoclay and Its Importance

2021 ◽  
pp. 71-81
Author(s):  
K. Nagaraju ◽  
T. N. V. K. V. Prasad ◽  
V. Munaswamy ◽  
Y. Reddi Ramu
Keyword(s):  
Clay Fraction ◽  
Cost Effective ◽  
Morphological Properties ◽  
Silicate Layer ◽  
Clay Material ◽  
Soil Fraction ◽  
Quaternary Ammonium Ions ◽  
Nano Clay ◽  
The One ◽  
Layer Groups

Clays are the one of the most important minerals and have numerous applications in nanotechnology, helps in improvise the product quality, cost effective and protect the environment from pollution. This review explained about the key characters of nanoclay particles and classification of nanoclay based on the sheets arrangements in their structural unit called layer. Nano clay major groups are kaoline-serpentine, smectite, mica, vermiculite, pyrophyllite talc and chlorite. The physicho-chemical and morphological properties of halloystite and mantmorillonite clay represents the 1:1 and 2:1 layer groups respectively. Nano clays are the group which is naturally present in the soil fraction of clay and most important nano clay material present in the soil are montmorillonite and allophone. Montmorillonite is a characteristically crystalline, phyllosilicate and hydrous silicate layer. Organo clays are the organically modified forms of the montmorillonite and formed from quaternary ammonium ions intercalation process and which have been used in inks, rheomodifiers, cosmetics, greases, as a additives in paints and also used in controlled release of drugs in delivery systems. Largest usage of nanoclaysis being practiced in polymer-clay nanocomposites. Organo clays are most importantly using in water treatment and pollution control. Allophane is formed by weathering of volcanic ash; it is non crystalline alluminium silicate derivative. Agricultural lands in Chile mostly formed by the allophane clay fraction. It is most suitable for enzyme mobilization. It also very useful in abortion of phenolic compounds, mill effluent colours and phosphates from waste water.

scholarly journals Destruction of bonds between soil particles in the process of water erosion

2015 ◽  
pp. 20-30
Author(s):  
O. G. Bushueva ◽  
A. V. Gorobets ◽  
N. G. Dobrovol’Skaya ◽  
Z. P. Kiryukhina ◽  
S. F. Krasnov ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Temperature ◽  
Solid Phase ◽  
Water Erosion ◽  
Water Current ◽  
Washout Rate ◽  
Shear Stresses ◽  
Soil Particles ◽  
Influence Of Water ◽  
Number Of Particles

It is known that tensile strength of soil samples is by three orders of magnitude greater than the shear stresses on the bottom of slope streams responsible for the detachment and transport of soil particles by water current. C.E. Mirtskhulava believed that detachment of soil particles by water current occurs due to the fatigue destruction of bonds between soil particles.Taking this fact into account, tensile strength is lower by two orders of magnitude. M.A. Nearing had an opinion that detachment of soil particles occurs in the points of separation of vortices from the bottom of the stream, where the shear stress is by two orders of magnitude higher than the average. These approaches did not explain overcoming by slope streams of the cohesion forces between soil particles. Studies of the influence of water temperature on the washout rate of model samples have shown that the soil erosion is highly dependent on the water temperature, which is close to the Van’t Hoff’s rule. This means that destruction of bonds between soil particles is probably the result of interaction between the soil solid phase and water molecules. Experiments have also shown that destruction of bonds between soil particles in the sample of chernozem monoaggregate soil occurs under a layer of still water. Upon the start of the water flow, particles that lost bond with the rest of the soil body immediately break away. The number of particles with disrupted bonds grows with the duration of the sample exposure to still water, although with some flattening. Experiments confirm the validity of the hypothesis of non-hydraulic nature of forces that disrupt inter-aggregate bonds during water erosion.

Dielectric permittivity of fine-grained fractions of soil samples from eastern Spain at 200 MHz

Geophysics ◽  
2010 ◽  
Vol 75 (1) ◽  
pp. J1-J9 ◽  
Author(s):  
Christina Salat ◽  
Andreas Junge
Keyword(s):  
Dielectric Permittivity ◽  
Water Content ◽  
Laboratory Data ◽  
Clay Fraction ◽  
Soil Samples ◽  
Small Scale ◽  
Carbonate Content ◽  
Dry Density ◽  
High Attenuation ◽  
Fine Grained

To provide a database for interpreting GPR field data by means of small-scale laboratory studies, we have determined the real and imaginary parts of the dielectric permittivity of fine-grained fractions of soil samples from eastern Spain in the laboratory. We use the parallel-plate method in combination with an impedance analyzer and focus on the frequency of [Formula: see text]. The measurements are compared to physical properties such as volumetric water content, dry density, clay fraction, and carbonate content. The results show the well-known increase in dielectric permittivity with increasing water content, as presented in the literature; however, our values are systematically higher. This deviation may be caused by the exceptionally high carbonate content of the samples. We establish a basic relationship between dielectric permittivity and water content that is characteristic for soils in the research area. In addition to the dominating influence of water on permittivity, we find a correlation with dry density as well, which is linear for dry samples. Finally, we calculate the attenuation coefficients and find high attenuation for samples with high clay fraction, even at low water contents. A 1D model of the permittivity distribution is constructed from borehole data (water content and layer thickness) coincident with a GPR profile and from the laboratory data. The modeled GPR trace explains the observation and thus connects laboratory measurements to GPR data.

scholarly journals The effect of shape and sizes of particles of wet quartz powders on complex dielectric permittivity in the frequency range of 10 kHz – 10 GHz

2021 ◽  
Vol 2140 (1) ◽  
pp. 012004
Author(s):  
P P Bobrov ◽  
E S Kroshka ◽  
O V Rodionova
Keyword(s):  
Dielectric Permittivity ◽  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Dielectric Permeability ◽  
Complex Dielectric Permittivity ◽  
Particle Sizes ◽  
Frequency Range ◽  
High Concentration ◽  
River Sand

Abstract The results of experimental studies of complex dielectric permeability of river sand and powders of granules of fused quartz with narrow distributions of particles in size at the frequencies from 10 kHz to 10 GHz are presented. The granule particles are spheres and the sand particles are irregularly shaped. The samples were moistened with distilled water and NaCl salt solution with conductivity of 0.1 and 0.77 S/m. It has been shown that the shape of the particles affects the complex dielectric permittivity (CDP) in the low frequency part of the range only when proportion of the solution is small and its concentration is weak. At full saturation of the samples with the solution and its high concentration, as well as in all cases at frequencies above 100 MHz, the influence of the particle shape is small. In the mid-frequency part of the range (from units to tens of megahertz) in a sample of quartz granules with small particles, there is a strong relaxation process, leading to a significant increase in the real part of the CDP. A similar, but slight increase is observed in samples of sand with larger particles. In the high-frequency range, the effect of the shape and particle sizes is very weak.

scholarly journals Sorption Characteristics of 137Cs and 90Sr into Rembang and Sumedang Soils

2018 ◽  
Vol 16 (3) ◽  
pp. 277 ◽  
Author(s):  
Budi Setiawan ◽  
Yusran Dani ◽  
Nurmaya Arofah
Keyword(s):  
Ionic Strength ◽  
Soil Sample ◽  
Metal Ion ◽  
Solid Phase ◽  
Radioactive Waste Disposal ◽  
Sorption Behavior ◽  
Planning And Design ◽  
Kd Values ◽  
Important Input ◽  
Radionuclide Activity

In order to understand the sorption behavior of 137Cs and 90Sr into soil sample from Rembang and Subang, it is important to estimate the effect of contact time, ionic strength and concentration of metal ion in the solution. For this reason, the interaction of 137Cs and 90Sr with soil sample has been examined. The study performed at trace concentration (~10-8 M) of CsCl and SrCl2, and batch method was used. NaCl has been selected as a representative of the ionic strength with 0.1; 0.5 and 1.0 M concentrations. Concentration of 10-8~10-4 M CsCl and SrCl2 were used for study the effect of Cs and Sr concentrations in solution. Apparent distribution coefficient was used to predict the sorption behavior. The sorption equilibrium of 137Cs and 90Sr into soil was attained after 5 days contacted with Kd value around 3300-4200 mL/g, where Kd was defined as the ratio of number of radionuclide activity absorbed in solid phase per-unit mass to the number of radionuclide activity remains is solution per-unit volume. Presence of NaCl as background salt in the solution affected Kd values due to competition among metal ions into soil samples. Increase of Cs or Sr concentration in solution made Kd value decreased drastically. This information is expected could provide an important input for the planning and design of radioactive waste disposal system in Java Island in the future.

scholarly journals Study on the particle shape of soft clay in Tianjin port

2019 ◽  
Vol 136 ◽  
pp. 03007
Author(s):  
Xuekui Wang ◽  
Dongjun Li ◽  
Yaoting Zhu
Keyword(s):  
Aspect Ratio ◽  
Soil Sample ◽  
Particle Shape ◽  
Soft Clay ◽  
Microscopic Analysis ◽  
Silty Clay ◽  
Soil Particles ◽  
Port Area ◽  
Average Aspect Ratio ◽  
Typical Soil

Microscopic analysis of soils has attracted wide attention, but at present, the analysis of particle shape of soft clay is still scarce. In this paper, the fractal dimension of particle aspect ratio, roundness and roughness is studied by selecting typical soil samples in Tianjin Port area. The main conclusions are as follows: (1) The average aspect ratio of clay, silty clay and silt is 1.56, 1.58 and 1.65, respectively, which shows that the smaller the soil particles are, the smaller the aspect ratio of the whole soil sample is; (2) The average roundness of clay, silty clay and silt are 0.91, 0.89 and 0.88, respectively, which indicates that the smaller the soil particles are, the closer the roundness of the whole soil sample is to 1, the closer the soil particles are to the circle. (3) The smaller the soil particles are, the smoother the surface of the particles is, and the smaller the soil particles are, the more obvious the correlation is.

scholarly journals The rapid assessment of concentrations and solid phase associations of macro- and micronutrients in alkaline soils by mid-infrared diffuse reflectance spectroscopy

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1339 ◽  
Author(s):  
I. Bertrand ◽  
L. J. Janik ◽  
R. E. Holloway ◽  
R. D. Armstrong ◽  
M. J. McLaughlin
Keyword(s):  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Solid Phase ◽  
Clay Fraction ◽  
Partial Least Square ◽  
Least Square ◽  
Alkaline Soils ◽  
Mid Infrared ◽  
Pls Analysis ◽  
Macro And Micronutrients

Chemical analysis is a crucial but often expensive and time consuming step in the characterisation of soils. Mid-infrared diffuse reflectance (MIR-DRIFT) spectroscopy coupled with partial least square (PLS) analysis was used to determine macro- and micronutrient concentrations of a range of alkaline soils from southern Australia. Solid phase associations of macro- and micronutrients were also investigated using the mineralogical information contained in the infrared spectra of soil samples. Results showed that MIR-PLS analysis is a powerful and rapid technique for the accurate prediction of more than 15 chemical properties from each soil sample spectrum. Correlation coefficients for MIR derived concentration versus laboratory determined values were greater than R2 = 0.80 for soil moisture, calcium carbonate concentration, total concentration of Mg, K, S, Fe, Al, Mn, Zn, Cu, and oxalate- extractable Al, Fe, Mn, and Si. In calcareous soils, sulfur was associated with carbonate and conversely Mg was more related to the clay concentration of soils. Micronutrients such as Fe, Zn, Mn, and Cu were positively associated with smectite/illite in the clay fraction and negatively with kaolinite. The potential use of these results in partitioning model to assess plant available micronutrients pools is discussed.

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