Application of radial return mapping algorithm for finite strain elastoplasticity in a hybrid finite element and particle-in-cell model

The radial return mapping algorithm within the computational context of a hybrid Finite Element and Particle-In-Cell (FE/PIC) method is constructed to allow a fluid flow FE/PIC code to be applied solid mechanic problems with large displacements and large deformations. The FE/PIC method retains the robustness of an Eulerian mesh and enables tracking of material deformation by a set of Lagrangian particles or material points. In the FE/PIC approach the particle velocities are interpolated from nodal velocities and then the particle position is updated using a suitable integration scheme, such as the 4th order Runge-Kutta scheme[1]. The strain increments are obtained from gradients of the nodal velocities at the material point positions, which are then used to evaluate the stress increment and update history variables. To obtain the stress increment from the strain increment, the nonlinear constitutive equations are solved in an incremental iterative integration scheme based on a radial return mapping algorithm[2]. A plane stress extension of a rectangular shape J2 elastoplastic material with isotropic, kinematic and combined hardening is performed as an example and for validation of the enhanced FE/PIC method. It is shown that the method is suitable for analysis of problems in crystal plasticity and metal forming. The method is specifically suitable for simulation of neighbouring microstructural phases with different constitutive equations in a multiscale material modelling framework.

Ecological fire regimes for the recovery and management of threatened small mammals in southern Australia

The application of fire to fauna management, particularly for endangered species, is a significant issue for wildlife managers. Mammals respond to fire regimes including intensity, frequency and season of occurrence, and changes in fire-regimes are implicated in detrimental effects on mammal communities. For many species temporal habitat change is a key factor affecting the persistence of populations. These species require the option of colonising the shifting habitat mosaic. There is substantial evidence that species such as the native rodents New Holland Mouse (Pseudomys novaehollandiae) and Heath Rat (Pseudomys shortridgei) are early successional species dependent on such temporal habitat changes. In conrast species such as the dasyurid marsupial, Swamp Antechinus (Antechinus minimus) are late successional species, which may take up to 20 years to recolonise. In many situations ecological fire regimes need to be implemented to increase areas of suitable habitat for population expansion and reintroductions. This paper assesses research findings and the development of management actions incorporating ecological fire regimes for the recovery of Pseudomyine rodents and the Swamp Antechinus. Spatially explicit models are required to determine changes and patterns at the landscape level. The prospect of global climate change also is of significance and needs to be assessed.

No smoke without fire : Benedict XVI and true liturgical reform

I read the recent comments on Pope Paul VI and the 'smoke of Satan' (July AD2000) with interest not long after I had finished re-reading the massive work by the late Archbishop Annibale Bugnini, generally considered to be the main architect of the liturgical reforms prior to, during, and after Vatican II.

Trial by fire

Victoria is facing its driest summer for nearly one hundred years, with conditions worse than in 1983 when the state was swept by the devastating Ash Wednesday bushfires. The fires were particularly fierce in Mount Macedon in central Victoria, and the Woodend Fire Brigade is in the front line of the struggle to avoid a repeat of Ash Wednesday. Trial by Fire follows this brigade as they do all that they can to keep their community safe from the devastation of the fires.

Trading activities and cross-sectional variation in stock expected return : evidence from Kuala Lumpur stock exchange

Trading activity has been considered as one of the possible factor that explains the cross-sectional variation in stock returns. In this study I use trading volume as a possible measure to proxy for liquidity as part of the trading activity. Monthly observations were used over a period 1995 to 2005 to examine the liquidity effect on stock expected returns. Based on findings it is appeared that level of liquidity does matter in explaining the expected stock returns in Malaysian capital market. While Fama-french factors also provide important explanation for stock returns. But none of the second moment variables proxying liquidity appeared to be statistically significant. However, momentum effect apprearently explain ing the cross-sectional variation in stock returns.