Nanocomposites based on polypyrrole (PPy) doped with molybdate (PPy(MoO 4 )) and montmorillonite (MMT) were prepared by chemical polymerisation. The morphology of nanocomposite particles was studied by scanning electron microscopy. The chemical structure of conducting polymers (CPs) in nanocomposites was characterised by Raman spectroscopy. The thermal analysis showed that all CPs in the nanocomposites were stable for more than 500 C. Energy diffraction X-ray showed that the amount of Mo in element the PPy(MoO 4 )/MMT nanocomposite was 5.55%. The corrosion protection mechanism of the nanocomposites was investigated by electrochemical methods, showing that MMT acted as a barrier layer in nanocomposite and molybdate as an inhibitor for corrosion protection of metal.

Multi-criteria decision making (MCDM) methods are systematical science projects to help decision-makers reach accurate decisions. Applying MCDM methods in the military is important because accurate decision making is the deciding factor for success and can reduce expenditure and increase defense capability. The full consistency method (FUCOM), one of the methods in the MCDM group, has many advantages, and its results are reliable. This paper aims to evaluate and select an appropriate fighter aircraft for Vietnam People’s Air Force. Using FUCOM as a decision-making process, we find the final weight values of criteria and apply the additive ratio assessment (ARAS) method to derive the final ranking of alternatives to comply with criteria. Sensitivity analysis is conducted and the result is compared with the weighted product method to substantiate the sturdiness of the proposed method. The results show the Su-35 as the best available solution.

No abstract

This paper deals with the nonlinear buckling and post-buckling of sandwich cylindrical panels with non-uniform porous core and functionally graded face sheets. The imperfect sandwich cylindrical panels are subjected to axial loading on elastic foundation. Based on the Donnell shell theory, with von Kármán geometrical nonlinearity, the governing equations are derived. The effects of elastic foundation, various panel geometrical characteristics, porosity parameters, and the thickness of the porous core are investigated. The effects of foundation parameters, porosity parameters, the thickness of the porous core, and material parameters are investigated.

No abstract