Microscopic calculations and energy expansions for neutron-rich matter

We investigate asymmetric nuclear matter with two- and three-nucleon interactions based on chiral effective field theory, where three-body forces are fit only to light nuclei. Focusing on neutron-rich matter, we calculate the energy for different proton fractions and include estimates of the theoretical uncertainty. We use our ab-initio results to test the quadratic expansion around symmetric matter with the symmetry energy term, and confirm its validity for highly asymmetric systems. Our calculations are in remarkable agreement with an empirical parametrization for the energy density. These findings are very useful for astrophysical applications and for developing new equations of state.Comment: 15 pages, 9 figures, published versio

A survey of Mechanical failure and design for Reliability of MEMS

In this paper, several experimental mechanical investigation techniques are presented to evaluate the reliability of micro-electro-mechanical systems (MEMS). Microsystems in recent years have spread in many everyday devices. We find micro-scale sensors and actuators in automotive, biomedical and aerospace applications where are demanded very strict performance requirements. Electromechanical non-linear coupling is often a crucial problem both in design and also for the reliability of the system. Mechanism of failure and failure modes has to be taken into account in order to evaluate the reliability of the final system. Focusing on device failure, it emerges that mechanical damage is the most significant source. In this paper a survey of recent advance in mechanical testing of MEMS is presented including: Mechanical fatigue, mechanical strength and plasticity, surface and contact failure and creep. Different design of testing specimens is discussed to identify the material properties and failure modes behavior in order to obtain design rules and strategies

Toward the Ab-initio Description of Medium Mass Nuclei

As ab-initio calculations of atomic nuclei enter the A=40-100 mass range, a great challenge is how to approach the vast majority of open-shell (degenerate) isotopes. We add realistic three-nucleon interactions to the state of the art many-body Green's function theory of closed-shells, and find that physics of neutron driplines is reproduced with very good quality. Further, we introduce the Gorkov formalism to extend ab-initio theory to semi-magic, fully open-shell, isotopes. Proof-of-principle calculations for Ca-44 and Ni-74 confirm that this approach is indeed feasible. Combining these two advances (open-shells and three-nucleon interactions) requires longer, technical, work but it is otherwise within reach.Comment: Contribution to Summary Report of EURISOL Topical and Town Meetings, 15-19 October 2012; missing affiliations added and corrected errors in Tab

Identification of Test Structures for Reduced Order Modeling of the Squeeze Film Damping in Mems

In this study the dynamic behaviour of perforated microplates oscillating under the effect of squeeze film damping is analyzed. A numerical approach is adopted to predict the effects of damping and stiffness transferred from the surrounding ambient air to oscillating structures ; the effect of hole's cross section and plate's extension is observed. Results obtained by F.E.M. models are compared with experimental measurements performed by an optical interferometric microscope.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

Spectrochemical Investigation of di methoxy Aniline Dithiocarbamate metal complexes-Biological activity

Dithiocarbomates are a class of sulfur-based metal-chelating compounds commonly used in industry, agriculture, and medicine. 2,6 di methoxy Aniline dithiocarbamate  Complexes of Copper and Ruthenium have been prepared  and Characterized by Spectroscopic methods like IR,NMR and also analysis of Biological activity. The investigation of these complexes confirmed that the stability of metal–ligands coordination through, S & S,N atoms as bidendate chelates.