The first paper, "A Study of Process and Tool Parameters on Friction Stir Welding of AA 6061 Joints", by Akash Shukla and Nairut Shah, examines the utilization of Taguchi method for augmenting tensile strength of friction stir welded Al 6061 alloy. On a comparison of the joint strength at different profiles, the authors have noted that the maximum weld strength (168 MPa) is obtained in the case of triangular tool profile than that of the hexagonal and circular tool profiles, at a rotation speed of 1600 rpm and a welding speed of 14 mm/min. The simulation results obtained indicated that the peak temperatures are maximum at the tool pin center; and when the speed of tool is more than the flow stress, the authors have observed an increase in temperature and a decrease in pressure.

Cryogenic treatment is a supplementary process to conventional heat treatment process in steels, and is used widely to enhance the wear resistance of the tool and improve the surface quality, by means of inexpensive and onetime permanent treatment affecting the entire section of the component unlike coatings. The performance of tool made of specific steel depends on the selection of steel, design, accuracy with which the tool is made, and application of proper heat treatment. In the second paper, "Effect of Cryogenic Treatment on Tool Life", Lakhwinder Pal Singh has carried out experimental studies to improve the cutting life of the tool during turning operations of AISIM2 tool steels. Three specimen groups-Conventionally Heat Treated (CHT), Shallow Cryogenically Treated (SCT) and Deep Cryogenically Treated (DCT)-were used in the experimental program, and with the help of a tool maker's Microscope, the flank wear of the specimen was measured at the end of each run. The author has noticed an improvement in tool life in terms of flank wear of DCT and SCT, by about 50% and 21.4%, respectively, as compared with CHT group.
In a wide range of engineering applications, extended surfaces-generally known as fins-find an application to increase the heat transfer rate from surfaces which are convectively cooled. Extensions on the finned surfaces are used to increase the surface area of the material. Even by slightly varying the material properties, the convective heat transfer coefficient rate can be varied. The fins are also known to be electroplated, and the base material is coated with another material having a higher thermal conductivity. In the paper, "Evaluating the Performance of Electroplated Composite Fins in Plate Heat Exchangers", A Kalyan Charan, Syed Wajihullah Ishaq, Mohammad Khaja Rafay and M Vinay Bhargav have analyzed thermal characteristics on the outer surface of the longitudinal fins of different materials using a steady state operation without internal heat generation in the fin. The thermal analysis of pure metal fins (aluminum fins and copper fins) and electroplated composite fins-aluminum with copper coating and copper with silver coating-carried out by the authors, in the laboratory using Pin-Fin apparatus and simulations evaluated in ANSYS, suggests that electroplated composite fins of copper with silver coating display most efficient values of convective heat transfer coefficient and heat flux.

The design of water tanks is crucial in earthquake-prone zones for the continued availability of water. After the Chilean earthquake of 1960, two mass-spring models were proposed to distinguish the basic dynamic properties of the elevated tank. Recent earthquakes of magnitudes ' 4.5, such as Uttarkashi (1991), Latur (1993), Bhuj (2001), etc., have indicated the vulnerability of storage tanks in the Indian subcontinent. The dynamic behavior of the elevated tanks is somewhat complex in nature. A new approach to dynamic force control mechanical systems is being implemented using high-impedance (mechanically stiff) systems such as hydraulic actuators, which are inherently velocity sources. In the last paper, "Seismic Assessment and Retrofitting of an Elevated Water Tank Using Active Tendon Control", Sarit Chanda has proposed an active tendon control panel consisting of prestressed cables, activators and a control element in the case of a heritage Tala tank in Kolkota, to make the water tank more resistant to seismic activity. In order to control two-directional sway which generates torsional effect, two-control setup is considered. The author has studied controlled versus uncontrolled response model of the elevated water tank, when any kind of vibration occurs on the ground surface. The results indicated a relative drift taking place equally on either side, resulting in an equilibrium state.