Dynamics of viscoelastic membranes

We determine both the in-plane and out-of-plane dynamics of viscoelastic membranes separating two viscous fluids in order to understand microrheological studies of such membranes. We demonstrate the general viscoelastic signatures in the dynamics of shear, bending, and compression modes. We also find a screening of the otherwise two-dimensional character of the response to point forces due to the presence of solvent. Finally, we show that there is a linear, hydrodynamic coupling between the in-plane compression modes of the membrane and the out-of-plane bending modes in the case where the membrane separates two different fluids or environments

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction

A representational predicament for a subordinate vis-à-vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC

THE PHENOMENOLOGICAL THEORIES OF MARTENSITE CRYSTALLOGRAPHY

The development of the basic phenomenological theories of martensite crystallography into the generalised multiple lattice invariant shear analysis of Acton et al., referred to as the CRAB theory is summarised. Unfortunately the generality of the CRAB theory, and perhaps the concise notation adopted in its presentation, appears to have obscured the fact that it incorporates, as a special case, a new and very simple, direct and powerful formulation of the basic single shear theory. In order to encourage wider use of this method of predicting the crystallographic features of martensitic transformations, the single shear CRAB theory is presented here, using elementary matrix algebra, for the case when the parent structure is referred to an orthonormal basis. The corresponding equations which arise when a general parent basis is adopted are also given using the notation of the tensor calculus, in an appendix

COMPUTER SIMULATION OF THE STRUCTURE OF bcc/hcp AND bcc/9R MARTENSITE INTERFACES

The structures of two interfaces of martensitic transformations in Cu Zn based alloys have been investigated using computer simulation techniques. A new interatomic potential has been developed which is assumed to represent all interactions between atoms in the parent bcc phase and the product hcp and 9R phases. Stable relaxed structures of bcc/hcp and bcc/9R interfaces have been found. In both cases the interface migrates into the bcc phase during the relaxation process. The boundary in the bcc/hcp computer model is broad involving about 6 (110) bcc planes of atoms, whereas that in the bcc/9R model is simpler involving only 3 planes. This suggests that the 9R product structure might be preferred in practice