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The work deals with the development of an effective numerical tool in the form of pseudospectral method for wave propagation analysis in anisotropic and inhomogeneous structures. Chebyshev polynomials are used as basis functions and Chebyshev-Gauss-Lobatto points are used as grid points. The formulation is implemented in the same way as conventional finite element method. The element is tested successfully on a variety of problems involving isotropic, orthotropic and functionally graded material (FGM) structures. The formulation is validated by performing static, free vibration and wave propagation analysis. The accuracy of the element in predicting stresses is compared with conventional finite elements. Free vibration analysis is carried out on composite and FGM beams and the computational resources saved in each case are presented. Wave propagation analysis is carried out using the element on anisotropic and inhomogeneous beams and layer structures. Wave propagation in thin double bounded media over long propagating distances is studied. Finally, a study on scattering of waves due to embedded horizontal and vertical cracks is carried out, where the effectiveness of modulated pulse in detecting small cracks in composites and FGMs has been demonstrated.

Incidence of unusually high numbers of stillbirths was observed at a piggery unit at the Veterinary University research farm in Tamil Nadu State of India. Systematic examination of the tissue from stillborn piglets led to the identification of presence of Porcine circovirus 2 (PCV2). Detailed analysis utilizing electron microscopy, polymerase chain reaction and sequencing confirmed the presence of PCV2 in the tissue of affected piglets. Histopathology analysis of the affected piglet tissue showed lymphoid cell depletion of lymphnodes, spleen and infiltration of liver, kidney, myocardium, etc. Retrospective examination of the morbidity and mortality history in the farm revealed high mortality in young and weanling piglets suggestive of PCV2 infection-induced diseases. This is the first report of emergence of major disease incidence in farmed swine due to PCV2 infection in India.

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