To determine how fracture–vuggy structure, pressure, and injection–production mode influence displacement efficiency in the water flooding process in fracture–vuggy reservoirs, two types of models were built based on the characteristic of such reservoir: two fracture models with different fracture apertures and two fracture– vuggy models with different sizes of vugs. A series of twophase fluid ...

a new model is proposed for two-dimensional simulation of the concrete fracture in compression. the model generated by using the voronoi diagram method and with considering random shape and distribution of full graded aggregates at the mesoscopic level. the aggregates modeled by combining irregular polygons, which then is placed into the concrete with no intersection between them. by this new m...

This study presents a probabilistic, 3-D framework to describe brittle fracture in structural components which incorporates weakest link statistics and a micromechanics model reflecting local damage of material. The Weibull stress (a,) emerges as a fracture parameter to define conditions leading to local material failure. This parameter is correlated with the macroscopic loading and used to des...

We examined the effect of a local anesthetic, dibucaine, on the plasma membrane of Tetrahymena pyriformis strain NT-1 using freeze-fracture electron microscopy. Intramembranous particles (IMPs) were distributed homogeneously on the plasma membrane of untreated cells. But, when Tetrahymena cells had been treated with 1.3 mM dibucaine for 5 min at growth temperature, freeze-fracture micrographs o...

Cracks in a rock mass subjected to a uniaxial stress will be preferentially closed depending on the angle between the fracture normal and the direction of the applied stress. If the prestress fracture distribution is isotropic, the effective elastic properties of such a material are then transversely isotropic due to the preferred alignment of the cracks. Velocity measurements in multiple direc...

The stress distribution on the tip of the cracks and the stress intensity factor on them are the main courses in the fracture mechanic. The stress intensity factor of the cracks with the different load exited and the different geometry are listed in the tables of the standard books. In all of them, the cracks are located in the central point of the plates. In the uniform edge loaded case, the c...

This article describes a new freeze-fracture autoradiographic technique for the detection of radioactive ligands associated with the surface of cells in monolayer or suspension culture. Since freeze-fracture replicas are produced in the conventional way, all membrane features normally seen in freeze-fracture are retained, and autoradiographic grains produced by the labeled ligands are seen supe...

The local approach to fracture (LAF) is a methodology aimed to calculate macroscopic fracture properties of a body, from the knowledge of the local stress strain field at the fracture site, and the modeling of the acting fracture mechanisms. In the present work, this method was applied to a CF8M steel, aged 30000 h at 325 °C, in order to elucidate if LAF could be able to describe the measured f...

High resolution measurements of fracture aperture of granite and sandstone rocks were performed using CAT scanner. The aperture distribution was statistically characterized for future experimental and numerical studies on single and multiphase flow and transport. The fracture aperture can be measured in-situ and nondestructively with CAT-scanning. The minimum pixel size is 0.27 x 0.27 mm, but f...

We used fracture-label and surface labeling techniques to characterize the distribution and topology of wheat germ agglutinin (WGA) receptors in the plasma membrane of boar sperm heads. We show that freeze-fracture results in preferential, but not exclusive, partition of WGA-binding sites with the outer (exoplasmic) half of the plasma membrane. Labeling of the inner (protoplasmic) half of the m...