most of the earth's crust contains fluids, and fractures are common throughout the upper part. they exist at a wide range of scales from micro-fractures within grains to major faults and shear zones that traverse the crust. in this paper, the stress-dependent permeability in fractured rock masses have been investigated considering the effects of nonlinear normal deformation and shear dilation o...

The routine measurement of direction-dependent reservoir rock properties like permeability often takes place along the axial direction of core samples. As permeability is a tensor property of porous materials, it should be fully described by a tensor matrix or by three main permeabilities in principal directions. Due to compaction, cementation, and other lithification processes, which take plac...

We have measured the levels of 3',5'-guanosine monophosphate (cyclic GMP) in isolated retinas from toad to investigate their correlation to the opening and closing of the light-dependent permeability of photoreceptors. When Ca2+-induced changes in cyclic GMP concentration are compared with the Ca2+-induced changes in the permeability of photoreceptor light-dependent channel, four quantitative d...

Brain tumor-associated cerebral edema arises because tumor capillaries lack normal blood-brain barrier function; vascular permeability factor (VPF, also known as vascular endothelial growth factor, VEGF) is a likely mediator of this phenomenon. Clinically, dexamethasone reduces brain tumor-associated vascular permeability through poorly understood mechanisms. Our goals were to determine if supp...

The objective of this study was to evaluate the effects of nitric oxide (NO) on H2O2-mediated endothelial permeability. H2O2(0.1 mM) increased permeability at 90 min to 298% of baseline. Spermine NONOate (SNO), an NO donor, at 0.1 or 1 mM did not alter permeability. However, 0.1 mM H2O2+ 1 mM SNO increased permeability to 764%, twice that of 0.1 mM H2O2alone. These treatments were not directly ...

The permeability characteristics of natural fracture systems are crucial to the production potential shale gas wells. To investigate behavior a regional fault that is located within Wufeng Formation, China, samples with micro-fractures was measured at different confining pressures and complemented helium pycnometry for porosity, computed micro-tomographic (µCT) imaging, comparison well testing ...