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In the present study, finite element analysis were carried out to investigate the ballistic performance of Al2O3-Kevlar 29/epoxy armour system impacted by a 4340 steel projectile. The perforation capacity of a 10 mm thick target was studied against a blunt, ogive, and conical shaped projectile with a fixed diameter and mass of 7.56 mm and 10.7 gm, respectively. The simulations were carried out in Ansys/Autodyn by considering the projectile as a deformable body. The variation of the ballistic limit velocity (BLV) and energy, progressive damage of the target, and projectile deformation were studied comprehensively. It was found that the nose configuration of the projectile significantly influence the target’s ballistic performance. The perforation capacity of the blunt projectile was lower than the ogive and conical shape in all the velocity regimes. At higher impact velocity (Vi>600 m/s), the target’s resistance was better against the ogive projectile than that of the sharp conical projectile. Interestingly, this phenomenon got reversed when the incident velocity nears the ballistic limit. Also, from the simulation results, it has been possible to obtain the optimum thicknesses of the components for a given total thickness of the armour.

Fibre reinforced polymer composites have been established as potential materials for making body armours. The present work depicts estimation of ballistic resistance of multilayer ceramic backed fibre reinforced composite target through 3D numerical simulation using Ansys/Autodyn software. The present numerical and material models have been validated against the results available in the literature. After that, the velocity–time history of the projectile is examined for impact velocities ranging between 330 to 1200 m/s. Here, the study has been focused on predicting the progressive damage and failure modes of the ceramic-composites target plate under impact. Also, the variation in residual velocities, time of penetration/perforation with different incident velocities, damage pattern in the deformable projectile and the kinetic energy of the impactor is studied. Finally, the trend of variation of ballistic limit velocity with different masses and diameter of the impactor has also been investigated.

Ceria-incorporated zirconia nanocomposites (CIZNCs) are prepared and characterized by some latest analytical tools. The efficiency of this material is evaluated toward arsenic(III) immobilization for removal via adsorption from its aqueous phases. The physicochemical aspects of this immobilization reaction have been reported at optimized pH 5.0. The kinetics of this reaction is of pseudo-second order type. The equilibrium data fit very well with the Langmuir isotherm with a monolayer adsorption capacity of 17.07 mg·g–1(226 mmol·kg–1) at 303 K. Analysis of reaction kinetics parameters shows that the fraction of molecules bearing the threshold energy of reaction (ΔN/Nav) is 0.99 at our working conditions. Thermodynamic analysis of equilibrium data reveals the exothermic and spontaneous nature of arsenic(III) adsorption over CIZNCs. X-ray photoelectron spectroscopy and cyclic voltammetric examinations have confirmed the oxidation of arsenic(III) to arsenic(V) over the CIZNC surface.

Through experimental testing and numerical simulations, this study examines the effects of ballistic events on thin FRP composite laminated plates fabricated using a hand lay-up method. Experimental ballistic impact tests using a pneumatic gun are conducted on composite plates reinforced with woven glass and woven Kevlar 29 fibers. An advanced three-dimensional finite element model programed in Ansys/Autodyn v19.1 is employed to verify the experimental findings and analyze the ballistic perforation characteristics of the target. The crucial material constants needed for the constitutive material model used in the simulation are acquired through precise experimentation on samples prepared from the fabricated laminates. Significant agreement is observed between the FE simulations and experimental findings, particularly concerning the assessment of residual velocities of the projectile and damage pattern in the laminates. The results of this study show that when subjected to ballistic impact by a flat-ended cylindrical projectile, the thin woven FRP composite primarily experiences damage characterized by delamination, fiber breakage and matrix cracking. Additionally, based on current simulations, it is observed that the ballistic limit velocity of the Kevlar 29/epoxy laminate exceeds that of GFRP by 25.64% when both materials have an equal thickness of 2.8 mm.

A straightforward method for synthesizing cyclopenta[c]chromanones is demonstrated. The strategy involves a [3+2] cycloaddition of VCPs and activated coumarins under Pd-catalyzed conditions. The reaction provides the desired products bearing up to four consecutive stereocenters with high diastereocontrol. Control experiments and density functional theory studies support the proposed mechanism and the observed diastereoselectivity in the product through a thermodynamically controlled pathway.

In this investigation, simulations are conducted to assess the ballistic resistance of an armor system composed of 95% alumina–Kevlar 29/epoxy composite subjected to normal and oblique impact. The oblique angles are varied from 0° to 70° in the step of 10-degree increments, and the projectile's impact velocities range between 220 and 1200 m/s. The present simulation results are aligned with existing numerical and experimental data available in the literature, demonstrating the consistency and reliability of the approach. Special attention is provided to obtain the critical oblique angle at which the projectile's penetration mode switches from perforation to embedment or ricochet. The simulation results also include the projectile's residual velocities, ballistic limit velocities, and the armor system's performance in terms of penetration or damage for normal and oblique impact. It is established that the oblique angle of the projectile significantly alters the effectiveness of the ceramic–composite armor against ballistic impact. When dealing with oblique angles below 30° (< 30°), the reduction in the projectile's residual velocity, as the obliquity angle increases, is limited to a maximum of 15%. This implies that the target's perforation resistance exhibits less sensitivity to the applied load of the projectile in this range. However, when incident angles exceed 45° (> 45°), the ballistic limit velocity has a significant and abrupt rise due to the augmented effective target thickness under oblique impact conditions.