Shales are complex porous materials, normally consisting of percolating and interpenetrating fluid and solid phases. The solid phase is generally comprised of several mineral components and forms an intricate and anisotropic microstructure. The shape, orientation, and connection of the two phases control the anisotropic elastic properties of the composite solid. We develop a theoretical framework that allows us to predict the effective elastic properties of shales. Its usefulness is demonstrated with numerical modeling and by comparison with established ultrasonic laboratory experiments. The theory is based on a combination of anisotropic formulations of the self‐consistent (SCA) and differential effective‐medium (DEM) approximations. This combination guarantees that both the fluid and solid phases percolate at all porosities. Our modeling of the elastic properties of shales proceeds in four steps. First, we consider the case of an aligned biconnected clay‐fluid composite composed of ellipsoidal inclusions. Anisotropic elastic constants are estimated for a clay‐fluid composite as a function of the fluid‐filled porosity and the aspect ratio of the inclusions. Second, a new processing technique is developed to estimate the distribution of clay platelet orientations from digitized scanning electron microphotographs (SEM). Third, the derived clay platelet distribution is employed to estimate the effective elastic parameters of a solid comprising clay‐fluid composites oriented at different angles. Finally, silt minerals are included in the calculations as isolated spherical inclusions.

No abstract

The interfacial zone separating cement paste and aggregate in mortar and concrete is believed to influence many of the properties of these composites. This paper presents a theoretical framework for quantitatively understanding the influence of the interfacial zone on the overall electrical conductivity of mortar, based on realistic random aggregate geometries. These same ideas may also be used to approximately predict the fluid permeability of mortar.

The hypothesis tested here was that subjects who view certain combinations of nonverbal behaviors in three channels (eye contact, posture, and distance) evidence a high degree of agreement in the assignment of specific meanings to these combinations. However, other combinations of these same channels, as well as unichannel behaviors, will result in little agreement about their meanings. An actor's nonverbal behaviors were filmed simultaneously by four cameras. One camera recorded behaviors in all three channels, whereas each of the other cameras filmed the behavior of a single channel. Three hundred and twenty subjects assigned meanings to the filmed behaviors by selecting from a checklist of 20 adjectives those adjectives that best described the actor's behavior. A panel of judges had previously found that these adjectives portrayed one of the following meanings: deprivation of status or esteem, deprivation of love or affection, provision of love or affection, provision of status or esteem. Five adjectives were selected from each class of meaning. In general, the results support the hypothesis. Some deviations were found and are discussed.

No abstract