Prediction for swelling deformation of fractal-textured bentonite and its sand mixtures in salt solution

Clay Minerals ◽  
2019 ◽  
Vol 54 (2) ◽  
pp. 161-167
Author(s):  
Guo-sheng Xiang ◽  
Feng Yu ◽  
Yong-fu Xu ◽  
Yuan Fang ◽  
Sheng-hua Xie
Keyword(s):  
Fractal Dimension ◽  
Surface Structure ◽  
Effective Stress ◽  
Salt Solution ◽  
Void Ratio ◽  
Distilled Water ◽  
Nacl Solution ◽  
Swelling Properties ◽  
Deformation Tests ◽  
Good Agreement

AbstractSwelling deformation tests of Kunigel bentonite and its sand mixtures were performed in distilled water and NaCl solution. The salinity of NaCl solution has a significant impact on the swelling properties of bentonite, but not on its surface structure. The surface structure was characterized using the fractal dimension Ds. Based on the fractal dimension, a unique curve of the em–pe relationship (em is the void ratio of montmorillonite and pe is the effective stress) at full saturation was introduced to express the swelling deformation of bentonite–sand mixtures. In mixtures with a large bentonite content, the swelling deformation always followed the em–pe relationship. In mixtures with a small bentonite content, when the effective stress reached a threshold, the void ratio of montmorillonite em deviated from the unique em–pe curve due to the appearance of a sand skeleton. The threshold of vertical pressure for mixtures in different solutions and the maximum swelling strains were estimated using the em–pe relationship. The good agreement between estimates and experimental data suggest that the em–pe relationship might be an alternative method for predicting the swelling deformation of bentonite–sand mixtures in salt solution.

A SIMPLE METHOD FOR TESTING THE FRACTAL DIMENSION OF COMPACTED BENTONITE IMMERSED IN SALT SOLUTION

2017 ◽  
Vol 24 (03) ◽  
pp. 1750040 ◽  
Author(s):  
GUOSHENG XIANG ◽  
YONGFU XU ◽  
SHENGHUA XIE ◽  
YUAN FANG
Keyword(s):  
Fractal Dimension ◽  
Salt Solution ◽  
Void Ratio ◽  
Nitrogen Adsorption ◽  
Laboratory Method ◽  
Nacl Solution ◽  
Simple Method ◽  
Sodium Chloride Solutions ◽  
Compacted Bentonite ◽  
Deformation Test

This study employs swelling deformation test for estimating the fractal dimension of salt-modified bentonite soil by measuring the void ratio of montmorillonite ([Formula: see text]) and the effective stress ([Formula: see text]). For the compacted Tsukinuno bentonite, a typical Na-montmorillonite, the fractal dimension is tested by the swelling deformation test conducted in sodium chloride solutions with different concentrations. According to the results, the fractal dimension of the specimens is essentially constant irrespective of the concentration of inundating NaCl solution. The strong correlation of the results from the swelling deformation test with those from the nitrogen adsorption test indicates that the swelling deformation test is an effective laboratory method for testing the fractal dimension of compacted bentonite in salt solution.

scholarly journals The Influence of Salt Solution on Morphological Changes in a Geosynthetic Clay Liner

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mochamad Arief Budihardjo
Keyword(s):  
Salt Solution ◽  
Morphological Changes ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Distilled Water ◽  
Nacl Solution ◽  
Geosynthetic Clay Liner ◽  
Clay Liner ◽  
Morphological Variations ◽  
Crystal Deposit

Morphological variations of geosynthetic clay liner (GCL) samples, hydrated with two different permeates, distilled water and NaCl solution (100 mM concentration), were observed in detail using microscopic analysis. After the GCL samples were hydrated with the NaCl solution, they were observed with an optical microscope. While the surface of the treated GCL samples was similar to the surface of the untreated GCL, a crystal deposit was found on the surface of the treated samples. Using a scanning electron microscope (SEM), a more solid appearance was observed for the bentonite particles contained in the GCL after the sample was hydrated with distilled water in comparison to the GCL sample that was hydrated with the NaCl solution. It appears that salt solution hydration results in less swelling of the bentonite particles. Furthermore, the energy-dispersive X-ray spectrometer (EDS) results showed that distilled water hydration had no effect on the distribution of the elements contained in the GCL samples. However, bound chlorine was observed, which demonstrated that the bentonite particles had absorbed the NaCl solution. In addition, changes in the hydraulic conductivity of the hydrated GCL samples were also observed.

Specificity of sodium chloride aversion of hypertensive rats

1959 ◽  
Vol 196 (6) ◽  
pp. 1326-1332 ◽  
Author(s):  
Melvin J. Fregly
Keyword(s):  
Sodium Chloride ◽  
Salt Solution ◽  
Distilled Water ◽  
Nacl Solution ◽  
Salt Solutions ◽  
Hypertensive Rats ◽  
Threshold Levels ◽  
Preference Threshold

Rats made hypertensive by encapsulation of both kidneys with latex envelopes manifest a relative NaCl aversion if given choice between water and .15 m NaCl solution to drink. The specificity of this aversion was tested by offering hypertensive rats choice between salt solutions, other than NaCl, and water. It was observed that hypertensive rats manifested aversions for KCl, Na2SO4, LiCl and Na saccharin which were similar in character to the NaCl aversion. As soon as hypertensive rats were able to differentiate between any of these salt solutions and distilled water offered simultaneously, they rejected the salt solutions in favor of water. These animals never ingested more of any salt solution used than water. With the exception of the Na saccharin solutions, normal rats ingested more salt solution than water and rejected salt solution only at concentrations 3–10 times above preference threshold levels. Hence, it would appear that the NaCl aversion manifested by hypertensive rats is not specific, but part of a general salt aversion.

Swelling characteristics of bentonite after long-term dissolution in alkaline solution

Clay Minerals ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 409-416
Author(s):  
Guo-sheng Xiang ◽  
Wei-min Ye ◽  
Li-yong Lv
Keyword(s):  
Fractal Dimension ◽  
Reaction Time ◽  
Alkaline Solution ◽  
Void Ratio ◽  
Swelling Properties ◽  
Swelling Characteristics ◽  
Naoh Solution ◽  
Swelling Coefficient ◽  
High Level

AbstractIn a high-level radioactive waste repository, bentonite may react with the alkaline solution produced by cement degradation. In this study, bentonite was mixed with alkaline solution in a closed system and reacted for 3–24 months. Furthermore, swelling tests were conducted on the alkaline-dissolved bentonite immersed in distilled water. The swelling deformation decreased significantly with increases in the concentration of NaOH solution and reaction time, and this was mainly due to montmorillonite dissolution. The fractal e–p relationship (e is the void ratio and p is the vertical pressure) with two calculation coefficients (the swelling coefficient and the fractal dimension) was employed to determine the swelling of alkaline-dissolved bentonite. The fractal dimension increased slightly with increasing reaction time or concentration of NaOH solution, as the dissolution traces caused by the alkaline solution favoured an increase in the irregularity and fractality of the bentonite surface. The swelling coefficient decreased linearly with decreasing montmorillonite content. In addition, the swelling coefficient and the fractal dimension were related exponentially to the reaction time in alkaline solution. A relationship between the swelling of alkaline-dissolved samples and the reaction time was proposed, which might be used to assess the swelling properties of bentonite barriers that would be affected by long-term dissolution of the alkaline solution in a closed repository.

scholarly journals Effect of storage of shelled Moringa oleifera seeds from reaping time on turbidity removal

2011 ◽  
Vol 9 (3) ◽  
pp. 597-602 ◽  
Author(s):  
M. Golestanbagh ◽  
I. S. Ahamad ◽  
A. Idris ◽  
R. Yunus
Keyword(s):  
Sodium Chloride ◽  
Salt Solution ◽  
Room Temperature ◽  
Moringa Oleifera ◽  
Storage Conditions ◽  
Distilled Water ◽  
Nacl Solution ◽  
Turbidity Removal ◽  
Indigenous Plant ◽  
And Storage

Moringa oleifera is an indigenous plant to Malaysia whose seeds are used for water purification. Many studies on Moringa oleifera have shown that it is highly effective as a natural coagulant for turbidity removal. In this study, two different methods for extraction of Moringa's active ingredient were investigated. Results of sodium chloride (NaCl) and distilled water extraction of Moringa oleifera seeds showed that salt solution extraction was more efficient than distilled water in extracting Moringa's active coagulant ingredient. The optimum dosage of shelled Moringa oleifera seeds extracted by the NaCl solution was comparable with that of the conventional chemical coagulant alum. Moreover, the turbidity removal efficiency was investigated for shelled Moringa oleifera seeds before drying in the oven under different storage conditions (i.e. open and closed containers at room temperature, 27 °C) and durations (fresh, and storage for 2, 4, 6 and 8 weeks from the time the seeds were picked from the trees). Our results indicate that there are no significant differences in coagulation efficiencies and, accordingly, turbidity removals between the examined storage conditions and periods.

scholarly journals Post-liquefaction reconsolidation of sand

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150745 ◽  
Author(s):  
O. Adamidis ◽  
G. S. P. Madabhushi
Keyword(s):  
Void Ratio ◽  
One Dimensional ◽  
Geotechnical Centrifuge ◽  
Significant Damage ◽  
Pore Water Pressures ◽  
The One ◽  
Crucial Parameter ◽  
Excess Pore ◽  
Good Agreement ◽  
Made In

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

Corrosion of polycrystalline ZnSe by alternating high voltage in a saline solution

1991 ◽  
Vol 6 (4) ◽  
pp. 667-669
Author(s):  
Joseph King
Keyword(s):  
Grain Boundary ◽  
High Voltage ◽  
Salt Solution ◽  
Saline Solution ◽  
Prolonged Exposure ◽  
Low Voltage ◽  
Mechanical Damage ◽  
Chemical Vapor ◽  
Nacl Solution ◽  
Chemical Vapor Deposited

Prolonged exposure of chemical vapor deposited, polycrystalline ZnSe to high ac voltages in the presence of a 1 molal NaCl solution induces severe mechanical damage. The damage takes the form of defects which originate at the surface and grow intergranularly into the bulk with a bush-like morphology. Neither exposure to the salt solution in the absence of the high voltage nor low voltage dc electrolytic exposure produces the defects. The damage may be associated with an intergranular hydride phase or grain boundary impurity segregations present or formed during the environmental exposure.

Isothermal Bubble Motion Through a Rotating Liquid

1972 ◽  
Vol 94 (1) ◽  
pp. 187-192 ◽  
Author(s):  
D. L. Schrage ◽  
H. C. Perkins
Keyword(s):  
Radial Direction ◽  
Terminal Velocity ◽  
Distilled Water ◽  
Analytical Prediction ◽  
Bubble Motion ◽  
Large Pressure ◽  
Rotating Liquid ◽  
Angular Velocities ◽  
Large Pressure Gradient ◽  
Good Agreement

An analytical and experimental study of isothermal bubble motion through a liguid which is itself in motion is presented. Both analytical and experimental results are reported for the velocities and trajectories of oxygen bubbles moving through a liquid annulus which is rotating at angular velocities ranging from 500 to 1500 rpm. Results are presented for both distilled water and glycerin. The analytical prediction of the trajectories and velocities showed good agreement with the experimental data. It was found that the bubbles, which were injected at the exterior of the liquid annulus, spiralled inward rapidly and, due to the large pressure gradient in the radial direction, did not reach a constant or terminal velocity.

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