The physics of foam

Weaire, D.; Phelan, Robert J.

doi:10.1088/0953-8984/8/47/055

Cited by 188 publications

(70 citation statements)

References 12 publications

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“…nearest neighbors (NN) 4.8±1.2 i i. next-nearest neighbors (NNN) 5.3±0.6 These numbers were derived by counting all NN and NNN, with and without various of the minor plates, and then averaging. These statistics are similar to those found in coarsening 2D soap froths [Weaire and Hutzler, 1999].…”

Section: Introductionsupporting

confidence: 82%

Plate Tectonics as a Far- From- Equilibrium Self-Organized System

Anderson¹

2013

Plate Boundary Zones

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Contained fluids heated from below spontaneously organize into convection cells when sufficiently far from conductive equilibrium. Fluids can also be organized by surface tension and other forces at the top. Plate tectonics was once regarded as passive motion of plates on top of mantle convection cells but it now appears that continents and plate tectonics organize the flow in the mantle. The flow is driven by instability of the cold surface layer and near-surface lateral temperature gradients. Plate tectonics may be a self-driven far-from-equilibrium system that organizes itself by dissipation in and between the plates. In this case the mantle is a passive provider of energy and material. The effect of pressure suppresses the role of the lower thermal boundary layer. I suggest that the state of stress in the lithosphere defines the plates, plate boundaries and locations of midplate volcanism, and that fluctuations in stress are responsible for global plate reorganizations and evolution of volcanic chains. Stress controls the orientations and activity of volcanic chains. The state of stress in the lithosphere is probably more important than the temperature of the mantle in localizing volcanism, although the normal variations of temperature in the mantle influence the topography and stress of the plate. Stress also controls the strength of the lithosphere. Volcanic chains should be regarded as stress-gauges and not as indicators of absolute plate motions. Changes in the orientation and magmatic activity of volcanic chains (e. g. Hawaiian and Emperor chains) cannot be due to abrupt changes in plate motions but can reflect changes in stress.

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Section: Introductionsupporting

confidence: 82%

Plate Tectonics as a Far- From- Equilibrium Self-Organized System

Anderson¹

2013

Plate Boundary Zones

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“…3) will be utilized for modeling the bubble in the foam layer. The foam has least surface area to maintain the bubbles stable that forces the bubbles into polyhedral shapes [12]. The surface of Kelvin's structure consists of six squares and eight hexagons, with a minimal seawater film thickness on each face.…”

Section: Physical Model Of Foam Layermentioning

confidence: 99%

“…The surface of Kelvin's structure consists of six squares and eight hexagons, with a minimal seawater film thickness on each face. These bubbles aggregate through the body-centered-cubic (BCC) structure for constructing the foam layer [12]. Note that the size of air bubbles is randomly distributed owing to the dynamic changing processes in the foam layer.…”

Section: Physical Model Of Foam Layermentioning

confidence: 99%

“…Table 2 summaries the numerical simulation parameters. It is commonly accepted that the probability density function of the average thickness of seawater film, p(t), follows the Rayleigh distribution [12] …”

Section: Parameters For Model Analysesmentioning

confidence: 99%

“…In the physical modeling of the foam layer, Kelvin's Tetrakaidecahedron structure [12] is used for modeling the polyhedral bubbles. The volume absorption, scattering, and extinction coefficients of the foam layer with varied water fractions are determined by numerically solving three-dimensional Maxwell's equations [13].…”

Section: Introductionmentioning

confidence: 99%

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A Numerical Study on Physical Characterizations of Microwave Scattering and Emission From Ocean Foam Layer

Jiang¹,

Xu²,

Chen³

et al. 2017

PIER B

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Abstract-This paper presents a numerical study of microwave scattering and emission from a foamcovered ocean surface. The foam layer is modeled as an inhomogeneous layer with randomly rough airfoam and foam-seawater boundaries. Kelvin's Tetrakaidecahedron structure is selected as the skeleton for simulating the air bubbles in the foam layer. The electromagnetic characteristics of the foam layer, including absorption and scattering coefficients for both vertical and horizontal polarizations, are calculated using a multilevel volume UV fast algorithm to accelerate the numerical computation of three dimensional Maxwell's equations. The surface scattering at air-foam and foam-seawater interfaces is determined using the integral equation model (IEM). The microwave emission from the foam-covered ocean surface, which accounts for multiple incoherent interactions within the foam layer and between the foam and interfaces, is modeled using the vector radiative transfer approach and numerically solved using the matrix doubling method. The model analyses of volume scattering and absorption of the foam layer reveal that the volume scattering coefficient of a foam layer increases with increasing water fraction at all selected frequencies, and its polarization dependence is negligible at a water fraction less than 2%. At 10.8 GHz and 18 GHz, the H-polarized scattering coefficient is smaller than the Vpolarized scattering coefficient for a larger water fraction; the opposite occurs at 36.5 GHz, at which V polarized scattering is weaker compared to H-polarized scattering. The model analyses of emission from a foam-covered ocean surface reveal that the emissivities at all selected operating frequencies have similar dependencies with water fraction and frequency, and they exhibit different sensitivities to water fractions. Moreover, the emissivities at high operating frequencies exhibit higher sensitivities to water fractions than the lower ones.

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Foams

Saint‐Jalmes

Durian

Weitz

2004

Kirk-Othmer Encyclopedia of Chemical Technology

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Foam is a nonequilibrium dispersion of gas bubbles in a relatively smaller volume of liquid containing surface‐active molecules. Foams that are relatively stable can be thought of as a form of condensed matter both solid‐like in being able to resist shear elastically, and liquid‐like in being able to flow and deform into arbitrary shapes. In this article, the extent to which the macroscopic stability and rheology of liquid‐based foams can be understood in terms of the underlying structure and dynamics of the constituent gas bubbles and liquid films, and their ultimate origin in terms of the physical chemistry of surface‐active molecules preferentially adsorbed at the gas–liquid interfaces are reviewed. Existing measurement techniques and survey applications in which custom foams play an important role are also discussed.

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The physics of foam

Abstract: Some recent progress in the study of liquid foams is reviewed in outline. Calculations of foam conductivity are presented, which further improve upon the approximation recently proposed by us, in accounting for the nonlinearity in the dependence of conductivity on liquid fraction.

Cited by 188 publications

References 12 publications

Plate Tectonics as a Far- From- Equilibrium Self-Organized System

Plate Tectonics as a Far- From- Equilibrium Self-Organized System

A Numerical Study on Physical Characterizations of Microwave Scattering and Emission From Ocean Foam Layer

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