The entanglement density of amorphous glassy polymers is well known to control their fracture mechanisms under tensile loading. There have been some reports indicating substantial deformation of a glassy polymer's surface region when exposed to interfacial friction. It is shown conclusively here that there is a direct correlation between the entanglement density of a glassy polymer and the defo...

Molecular dynamics simulations were employed to study the mechanical properties and true stress development in amorphous polymeric materials. As expected, the true stress levels are much higher than those indicated by the engineering stress. However, the true stress behavior was found to be not only quantitatively but also qualitatively different from that of the engineering stress. Highly loca...

Reservoir monitoring improves our understanding of reservoir behaviour and helps achieve more effective reservoirmanagement and prediction of future performancewith obvious economic benefits. It relies on an integrated approach involving both surveillance (well or surface based; seismic, electrical, leakage, flow and deformation measurements, etc.) and modelling. Surface deformation monitoring ...

We discuss the 2 + 1 dimensional description of the Φ1,3 deformation of the minimal model Mp leading to a transition Mp → Mp−1. The deformation can be considered as an addition of the charged matter to the Chern-Simons theory describing a minimal model. The N = 1 superconformal case is also considered. e-mail address: [email protected] † On leave of absence from ITEP, B.Cheremyshkinskay...

Twinning in metals is normally a permanent plastic deformation mechanism. Here we report reversible twinning in high stacking fault energy (SFE) aluminum. Twinning and spontaneous detwinning at the crack tip have been captured in situ during tensile straining under a transmission electron microscope. Both the in situ observation and the molecular dynamics simulations reveal a two-stage detwinni...

We investigate the quasistatic mechanical response of soils under cyclic loading using a discrete model of randomly generated convex polygons. This response exhibits a sequence of regimes, each one characterized by a linear accumulation of plastic deformation with the number of cycles. At the grain level, a quasiperiodic ratchetlike behavior is observed at the contacts, which excludes the exist...

The atmospheric artifacts in interferometric synthetic aperture radar (InSAR) measurements are a large error source in accurately estimating terrain deformation signals [1]. For example, the large magnitude, high spatial frequency atmospheric bubbles can easily be misinterpreted as deformation phenomena [2, 3]. Various InSAR time series techniques, such as the Permanent Scatterer (PS) and Small...

An arbitrary deformation of a material can always be described as the sum of a change in volume and a change in shape at constant volume (shear). Assuming constant structure, the change in volume is recovered when the load is removed, since the atoms can simply relax back to their equilibrium sizes. The change in shape, on the other hand, may or may not be recovered, since the atoms can relax i...

This paper presents a solution to implement neutral argon plasma (NAP) in minimally invasive medical devices (MIMD) for therapy in endoscopy. The NAP system is composed by compressed inert gas (argon), two electrodes and a high-voltage source to ionize the argon. The miniaturization of an argon reservoir is required. The finite element method simulation of a small reservoir of 304 L stainless s...

The algebraic cohoroology and the spectral sequences for a Z2-graded Lie algebra are briefly reviewed. The reducibility property of a strongly semisiiaple Lie superalgebra is established. The role of second and third cohomologies in the deformation of a Lie superalgebra is discussed. Using spectral sequences, the second cohomology of full BRS algebra is shown to be W and the third cohomology be...