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Piston subsystem is subjected to very complex but dynamic forces. Such forces include combustion gas force, inertial dynamics forces, lubricating action/damping forces, contact friction forces to name a few. Further, piston ring mounted in piston in addition to these forces experiences out ward springing action inside engine mounting due to inherent elasticity. To evaluate the strength of reciprocating piston, the simultaneous effect of all these forces should be considered, while simulating through finite element method. With effect of all these forces, the currently considered piston of Gray Cast Iron, aluminum alloy and Metal-Metric-Composite (Si-C) are given four different crown shapes for optimization of material and crown geometry for better strength. The rings mounted are considered to be coated with Nickasil. The combined numerical simulation for contact and finite element simulation of structural strength and their correlation suggest many important outcomes. Von-Misses stress is maximum in case of type-B Al-alloy crown, while it is minimum in case of type-C SiC metal matrix piston.

Background Silicon and aluminum oxides make the bulk of agricultural soils. Plants absorb dissolved silicon as silicic acid into their bodies through their root. The silicic acid moves with transpiration to target tissues in the plant body where it polymerizes into biogenic silica. Mostly, the mineral forms on a matrix of cell wall polymers that create a composite material. Historically, silica deposition (silicification) was supposed to occur once water evaporated from the plant surface leaving behind increased concentration of silicic acid within plant tissues. However, recent publications indicate that certain cell wall polymers and proteins initiate and control the extent of plant silicification. Scope Here we review recent publications on the polymers that scaffold the formation of biogenic plant silica, and propose a paradigm shift from spontaneous polymerization of silicic acid to dedicated active metabolic processes that control both location and extent of the mineralization. Conclusion Protein activity concentrate silicic acid beyond its saturation and polymeric structures at the cell wall stabilize it and allow its flow with the transpiration stream, or bind it and allow its initial condensation. Nucleation and further polymerization is enabled on a polymeric scaffold, which is embedded within the mineral. Deposition is terminated once free silicic acid is consumed or the chemical moieties for its binding are saturated.

Non structural elements in a building are those members which come in to the path of earthquake force affected by it but do not take part in the dissipation of energy produced during an earthquake. Failure of these members during an earthquake causes not only economic losses but human life too. The building will remain safe after an earthquake but may become unserviceable for the purpose for which it has been constructed. For the earthquake resistant design of building study of behavior of these members is necessary. It has been found that seismic design of structure is given much attention but very little attention has been given to protecting non structural member of the buildings 1 . This article has been prepared after studying codes and articles published in various journals. The main objective of this article is to make design people aware of the importance of non structural element in the earthquake resistant design of buildings.