The permeability of soils with organic fluids

1991 ◽  
Vol 28 (1) ◽  
pp. 140-147 ◽  
Author(s):  
Muniram Budhu ◽  
R.F. Giese Jr. ◽  
George Campbell ◽  
Lynn Baumgrass
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Pure Water ◽  
Clay Soils ◽  
Organic Liquids ◽  
Exponential Equation ◽  
General Observation ◽  
Acetone Water ◽  
Constant Viscosity ◽  
Organic Fluids

Permeability measurements, using a consolidometer, were made for kaolinite, montmorillonite, and a clay-rich soil (the Lockport clay) with a variety of organic liquids and water as permeants. These data, along with selected values from the literature, were used to evaluate several theories that have been proposed as explanations for the general observation that permeabilities of clay soils with organic fluids as the permeants are higher than with water as the permeant. Of the several obvious differences in physical properties between water and organic liquids (e.g., dielectric constant, viscosity, dipole moment, specific gravity, and surface tension), only the dielectric constant provided a consistent correlation with the permeabilities used in this study. The permeabilities for the organic chemicals used in this study can be predicted using the measured permeability for the soil with water as the permeant and the dielectric constant of the organic by way of an exponential equation. For mixtures of acetone–water and methanol–water, the permeabilities did not vary linearly with the composition; the permeabilities remained close to values for pure water until approximately 70% (by volume) of the fluid was organic. Key words: permeability, organics, dielectric constant, soils.

Electrohydrodynamic stability: Taylor–Melcher theory for a liquid bridge suspended in a dielectric gas

2002 ◽  
Vol 452 ◽  
pp. 163-187 ◽  
Author(s):  
C. L. BURCHAM ◽  
D. A. SAVILLE
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Electric Fields ◽  
Liquid Bridge ◽  
Numerical Solutions ◽  
Specific Conductivity ◽  
Axisymmetric Deformation ◽  
Aspect Ratios ◽  
The Stability ◽  
Theory And Experiment

A liquid bridge is a column of liquid, pinned at each end. Here we analyse the stability of a bridge pinned between planar electrodes held at different potentials and surrounded by a non-conducting, dielectric gas. In the absence of electric fields, surface tension destabilizes bridges with aspect ratios (length/diameter) greater than π. Here we describe how electrical forces counteract surface tension, using a linearized model. When the liquid is treated as an Ohmic conductor, the specific conductivity level is irrelevant and only the dielectric properties of the bridge and the surrounding gas are involved. Fourier series and a biharmonic, biorthogonal set of Papkovich–Fadle functions are used to formulate an eigenvalue problem. Numerical solutions disclose that the most unstable axisymmetric deformation is antisymmetric with respect to the bridge’s midplane. It is shown that whilst a bridge whose length exceeds its circumference may be unstable, a sufficiently strong axial field provides stability if the dielectric constant of the bridge exceeds that of the surrounding fluid. Conversely, a field destabilizes a bridge whose dielectric constant is lower than that of its surroundings, even when its aspect ratio is less than π. Bridge behaviour is sensitive to the presence of conduction along the surface and much higher fields are required for stability when surface transport is present. The theoretical results are compared with experimental work (Burcham & Saville 2000) that demonstrated how a field stabilizes an otherwise unstable configuration. According to the experiments, the bridge undergoes two asymmetric transitions (cylinder-to-amphora and pinch-off) as the field is reduced. Agreement between theory and experiment for the field strength at the pinch-off transition is excellent, but less so for the change from cylinder to amphora. Using surface conductivity as an adjustable parameter brings theory and experiment into agreement.

Surface Tension Estimation of Binary System of Several Organic Liquids

2010 ◽  
Vol 28 (5) ◽  
pp. 469-476
Author(s):  
A. A. Saleh ◽  
H. A. A. Algane ◽  
E. T. Hashim
Keyword(s):  
Surface Tension ◽  
Binary System ◽  
Organic Liquids

Über die Deutung der Gleichstromleitfähigkeit organischer Flüssigkeiten bei niedrigen Temperaturen

1964 ◽  
Vol 19 (9) ◽  
pp. 1070-1075
Author(s):  
H. Vogel ◽  
H. Bässler
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Liquid State ◽  
Static Dielectric Constant ◽  
Coulomb Energy ◽  
Organic Liquids ◽  
Characteristic Distance ◽  
Lower Region ◽  
Pure Coulomb ◽  
The Law

The activation energy of the d. c. conductance of organic liquids lies between 0.04 and 0.45 eV in the lower region of temperature of their liquid state. A comparison of these values with the static dielectric constant shows, that the activation energy may be regarded as a pure COULOMB energy: E2 = e2/2 ε r . The characteristic distance r has the approximate value of 8.5 Å for hydrocarbons. It decreases for halogen- and nitro-derivates. Formerly it was found that the conductivity of mixtures obeys the law σM = σAC · σB1-C. This can easily be explained assuming εM = c εA + (1 — c) εB. In the case of rather different ε values or of homologuous compounds forming complexes, σ increases. This is identical with a kink in the log σ (c) -curve.

scholarly journals On the contribution of Aitken mode particles to cloud droplet populations at continental background areas – a parametric sensitivity study

2007 ◽  
Vol 7 (3) ◽  
pp. 6077-6112
Author(s):  
T. Anttila ◽  
V.-M. Kerminen
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Chemical Composition ◽  
Pure Water ◽  
Particle Surface ◽  
Chemical Properties ◽  
Sensitivity Study ◽  
Geometric Standard Deviation ◽  
Cloud Droplets ◽  
Aitken Mode

Abstract. Aitken mode particles are potentially an important source of cloud droplets in continental background areas. In order to find out which physico-chemical properties of Aitken mode particles are most important regarding their cloud-nucleating ability, we applied a global sensitivity method to an adiabatic air parcel model simulating the number of cloud droplets formed on Aitken mode particles, CD2. The technique propagates uncertainties in the parameters describing the properties of Aitken mode to CD2. The results show that if the Aitken mode particles do not contain molecules that are able to reduce the particle surface tension more than 30% and/or decrease the mass accommodation coefficient of water, α, below 10−2, the chemical composition and modal properties may have roughly an equal importance at low updraft velocities characterized by maximum supersaturations <0.1%. For larger updraft velocities, however, the particle size distribution is clearly more important than the chemical composition. In general, CD2 exhibits largest sensitivity to the particle number concentration, followed by the particle size. Also the shape of the particle mode, characterized by the geometric standard deviation (GSD), can be as important as the mode mean size at low updraft velocities. Finally, the performed sensitivity analysis revealed also that the chemistry may dominate the total sensitivity of CD2 to the considered parameters if: 1) the value of α varies at least one order of magnitude more than what is expected for pure water surfaces (10−2–1), or 2) the particle surface tension varies more than roughly 30% under conditions close to reaching supersaturation.

scholarly journals Aerosol hygroscopicity at high (99 to 100%) relative humidities

2009 ◽  
Vol 9 (4) ◽  
pp. 15595-15640 ◽  
Author(s):  
C. R. Ruehl ◽  
P. Y. Chuang ◽  
A. Nenes
Keyword(s):  
Surface Tension ◽  
Inorganic Compounds ◽  
Droplet Diameter ◽  
Pure Water ◽  
Sodium Dodecyl ◽  
Bulk Solution ◽  
Active Compounds ◽  
Surface Active ◽  
Surface Active Compounds ◽  
Aerosol Hygroscopicity

Abstract. The hygroscopicity of an aerosol largely determines its influence on climate and, for smaller particles, atmospheric lifetime. While much aerosol hygroscopicity data is available at lower relative humidities (RH) and under cloud formation conditions (RH>100%), relatively little data is available at high RH (99.2 to 99.9%). We measured the size of droplets at high RH that had formed on particles composed of one of seven compounds with dry diameters between 0.1 and 0.5 μm, and calculated the hygroscopicity of these compounds. We use a parameterization of the Kelvin term, in addition to a standard parameterization (κ) of the Raoult term, to express the hygroscopicity of surface-active compounds. For inorganic compounds, hygroscopicity could reliably be predicted using water activity data and assuming a surface tension of pure water. In contrast, most organics exhibited a slight to mild increase in hygroscopicity with droplet diameter. This trend was strongest for sodium dodecyl sulfate (SDS), the most surface-active compound studied. The results suggest that partitioning of surface-active compounds away from the bulk solution, which reduces hygroscopicity, dominates any increases in hygroscopicity due to reduced surface tension. This is opposite to what is typically assumed for soluble surfactants. Furthermore, we saw no evidence that micellization limits SDS activity in micron-sized solution droplets, as observed in macroscopic solutions. These results suggest that while the high-RH hygroscopicity of inorganic compounds can be reliably predicted using readily available data, surface-activity parameters obtained from macroscopic solutions with organic solutes may be inappropriate for calculations of the hygroscopicity of micron-sized droplets.

Temperature and Concentration of the Dielectric Constant of Mixtures of Organic Liquids and Water

1960 ◽  
Vol 213O (1) ◽  
Author(s):  
G. P. Srivastasa ◽  
Y. P. Varshni
Keyword(s):  
Dielectric Constant ◽  
Organic Liquids

scholarly journals An Experimental Study on Wetting of Coal Dust by Surfactant Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yidan Jiang ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Ye Pei ◽  
Gaogao Wu
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Reverse Osmosis ◽  
Sodium Sulfate ◽  
Moisture Absorption ◽  
Coal Dust ◽  
Pure Water ◽  
Surfactant Solution ◽  
Limited Range ◽  
Dust Reduction

Surfactants can improve the wetting performance of the dust-reduction spraying water, thus improving the dust-reduction effect by spray. In this study, the performance of surfactant solution in wetting coal dust was investigated through experiments. In addition, the effects of surfactant type, mass fraction, metamorphic degree of coal, particle size, and additives were investigated. According to the results of surface tension experiments, the surface tension of the solution decreased with the increase of the concentration of surfactant. However, after reaching CMC, the surface tension did not have significantly decrease. SDBS and OP-10 had higher efficiency in decreasing the surface tension than the other two types of surfactants. The addition of sodium sulfate additives can further reduce the surface tension of the surfactant solution by a limited range. The coal dust wetting experiment showed that with the increase in the concentration of the surfactant, the contact angle of the droplets on the coal dust tablet was continuously reduced, and the wettability of the solution was continuously improved. The wettability of the OP-10 solution was optimal. At the same concentration, the minimum contact angle can be obtained in the OP-10 solution. As the contact angle of the coal dust increased, the growth rate in the coal dust reverse osmosis moisture absorption of the surfactant solution relative to the pure water increased. After the addition of sodium sulfate, the reverse osmosis moisture absorption of coal dust increased to varying degrees. In addition, as the concentration of additives increased, the moisture absorption of coal dust increased.

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