Critical State

Kinematic hardening rules formulated in a hardening/dynamic recovery format are examined for simulating rachetting behavior. These rules, characterized by decomposition of the kinematic hardening variable into components, are based on the assumption that each component has a critical state for its dynamic recovery to be activated fully. Discussing their basic features, the authors show that they can predict much less accumulation of uniaxial and multiaxial ratchetting strains than the Armstrong and Frederick rule. Comparisons with multilayer and multisurface models are made also, resulting in a finding that the simple one in the present rules is similar to the multilayer model with total strain rate replaced by inelastic (or plastic) strain rate. Part II of this work deals with applications to experiments.

Two asphalt mixtures, a dense graded mix (DGM) and a Stone Mastics Asphalt (SMA) were investigated using triaxial shear strength testing. The objective was to study the effect of air voids content on the mixture strength properties by varying air voids content ...

Two significant consequences of quantum fluctuations are entanglement and criticality. Entangled states may not be critical but a critical state shows signatures of universality in entanglement. A surprising result found here is that the entanglement entropy may become arbitrarily large and negative near the dissociation of a bound pair of quantum particles. Although apparently counter-intuitive, it is shown to be

Abstract: When threatened by crises such as global terrorism, financial collapse, pandemic diseases, and natural disasters, states may resort to measures that harm the interests of foreign investors protected under the bilateral investment treaty (BIT) regime. Many such ...

A test of quantum mechanics proposed by K. Popper and dealing with two-particle entangled states emitted from a fixed source has been criticized by several authors. Some of them claim that the test becomes inconclusive once all the quantum aspects of the source are considered. Moreover, another criticism states that the predictions attributed to quantum mechanics in Popper's analysis are untenable. We reconsider these criticisms and show that, to a large extend, the `falsifiability' potential of the test remains unaffected.

The marine sector surrounding Panarea Island (Aeolian Islands, South Italy) is affected by widespread submarine emissions of CO2 -rich gases and thermal water discharges which have been known since the Roman Age. On November 3rd, 2002 an anomalous degassing event affected the area, probably in response to a submarine explosion. The concentrations of minor reactive gases (CO, CH4 and H2) of samples collected in November and December, 2002 show drastic compositional changes when compared to previous samples collected from the same area in the 1980s. In particular the samples collected after the November 3rd phenomenon display relative increases in H2 and CO and a strong decrease in the CH4 contents, while other gas species show no significant change. The interaction of the original gas with seawater explains the variable contents of CO2, H2S, N2, Ar and He which characterize the different samples, but cannot explain the large variations of CO, CH4 and H2 which are instead compatible with changes in the redox, temperature and pressure conditions of the system. Two models, both implying an increasing input of magmatic fluids are compatible with the observed variations of minor reactive species. In the first one, the input of magmatic fluids drives the hydrothermal system towards atypical (more oxidizing) redox conditions, slowly pressurizing the system up to a critical state. In the second one, the hydrothermal system is flashed by the rising high-T volcanic fluid, suddenly released by a magmatic body at depth. The two models have different implications for volcanic surveillance and risk assessment: In the first case, the November 3rd event may represent both the culmination of a relatively slow process which caused the overpressurization of the hydrothermal system and the beginning of a new phase of quiescence. The possible evolution of the second model is unforeseeable because it is mainly related to the thermal, baric and compositional state of the deep magmatic system that is poorly known.