A method of calculating dispersion curves for guided waves in slight, azimuthally anisotropic formations is developed with perturbation theory. The fluid is assumed to be inviscid, the formation perfectly elastic and homogeneous, and the ·borehole wall cylindrical. The first step is calculating the elastic moduli for a transversely isotropic formation whose moduli are close to those for the azi...

Understanding the controls on the elastic properties of reservoir rocks is crucial for exploration and successful production from hydrocarbon reservoirs. We studied the static and dynamic elastic properties of shale gas reservoir rocks from Barnett, Haynesville, Eagle Ford, and Fort St. John shales through laboratory experiments. The elastic properties of these rocks vary significantly between ...

In order to point out the influence of thermal history (fictive temperature) and OH content on the elastic properties of silica glass, we have performed high resolution in situ Brillouin spectra of SiO2 glass from room temperature to the supercooled liquid at 1773K across the glass transition. The well known anomalous increase of elastic modulus in the glassy state and in the supercooled liquid...

For the limitation of experimental methods in crystal characterization, in this study, the mechanical, thermodynamic and electronic properties of wurtzite and zinc-blende GaN crystals were investigated by first-principles calculations based on density functional theory. Firstly, bulk moduli, shear moduli, elastic moduli and Poisson's ratios of the two GaN polycrystals were calculated using Voig...

The structural and elastic properties of strongly curved cylindrical interface are characterised by spontaneous curvature, spontaneous area per molecule and three elastic moduli corrcsponding respectively to area extension, bending and mixed deformation of

OBJECTIVES To evaluate and compare the flexural strength and the elastic moduli of three provisional crown materials (methyl methacrylate based autopolymerized resin, bis acryl composite based autopolymerized resin and urethane dimethacrylate based light polymerized resin) after storing in artificial saliva and testing at intervals of 24 hours and 7 days. STUDY DESIGN A metal master mould wit...

The viscoelastic properties of planar phospholipid (dimyristoylphosphatidylcholine) bilayer membranes at 308 K are studied, many of them for the first time, using the nonequilibrium molecular dynamics simulation (NEMD) method for membrane area change. First, we present a unified formulation of the intrinsic three-dimensional (3D) and apparent in-plane viscoelastic moduli associated with area ch...

Expressions for the pressure-dependent apparent elastic constants of cubic crystals are derived in terms of their original secondand third-order elastic constants. New expressions are obtained for the apparent compliances and their pressure derivatives. Results are shown to be in agreement with those based on the apparent elastic moduli. ( 1998 Elsevier Science Ltd. All rights reserved.

S U M M A R Y We discuss analytical results for seismic radiation during rapid episodes of inelastic brittle deformation that include, in addition to the standard moment term, a damage-related term stemming from changes of elastic moduli in the source region. The radiation from the damagerelated term is associated with products of the changes of elastic moduli and the total elastic strain compo...