This issue has three papers. In the first paper, "Impact Energy Study of Foam-Filled Crashworthy Structures of Aluminum and Mild Steel Square Tubes", the author, Sagar K G A, has presented experimental results using aluminum and mild steel square tubes of 2 mm and 3 mm and two types of foam filler materials with varying densities. Based on the examination of the results obtained to assess their peak load resistance through quasi-static compression tests, the author has inferred that the use of 3 mm aluminum square tube filled with the low-density polyurethane foam (75 kg/m3) is optimal to enhance increased resistance to deformation and also to give improved impact absorption.

Fins are most commonly used in heat exchange devices to enhance convective heat transfer, and find application in a wide range of engineering devices. Developing the most efficient heat exchange systems is challenging in the context of ongoing research on the design of new micro- and nano-electronic devices. The second paper is on the application of numerical analysis and experimental evaluation to pin-fin heat exchangers that are widely required for the cooling of electronic components. In the paper, "Novel Arrangement for Pin-Fin Heat Sinks to Improve Efficiency of Thermal Dissipation", the authors, Juan Ramirez-Vazquez and Martin Nieto-Perez, have carried out numerical analysis with a proper pin-fin heat sink of square shape (pin profile: rectangular) design in order to determine the best configuration that improves the thermal-hydraulic dissipation. Deflectors are used in the design in such a way that they help direct the air flow to pass through rectangular cross-sectional fins. The experimental results are found to be in-line with the numerically evaluated results. Overall, the deflector elements implemented in an 8 x 8 pin-fin configuration are found to help prevent heat stagnation. Studies of this nature with a set of new geometric parameters of pin-fins and fin-deflectors would throw light on optimizing the heat flow and further improving the efficiency of thermal dissipation.

Composite materials like Glass Fiber Reinforced Polymer (GFRP) have been gaining importance due to their low weight and high mechanical properties in successfully replacing conventional metals in several manufacturing industries, such as aerospace, defense, nuclear, automotive, etc. In spite of the several favorable properties associated with GFRP composites, machining of GFRP in the processes such as trimming, turning, milling and drilling is significantly different as compared to other engineering materials because of the complex nature (inhomogeneity and anisotropy). Given these complexities, it is all the more important to study the effect of cutting parameters and material parameters on its machining process to arrive at best parametric settings to achieve improved quality and increased productivity. In the last paper, "Drilling Performance and Multi-Resolution Vibration Analysis of GFRP", the authors, Arpan Maity, Rayapati Subbarao, Nirmal Kumar Mandal, Arghya Chattopadhyay and Subhajit Chattopadhyay, have experimentally studied the effect of cutting parameters for different cutting speeds and feed rates on the cutting force (thrust force and torque), vibration, delamination factor and surface roughness of the GFRP material. They have noted that the start point of the torque cycle is delayed for a few seconds than the thrust force, and that the torque decreases with increasing cutting speed. At higher feed rates, the increment in acceleration is less, and all the coefficients of vibration first decreased, and all the coefficients started increasing at a feed rate of 300 mm/min. The delamination factor is found to increase with cutting speed, resulting in the increase in cutting force. The surface became much smoother for cutting speed of 1000 rpm and feed rate of 500 mm/min compared to other cases. Overall, the results illustrate significant relations between drilling factors and drilling responses.