localized head slip with localized thread slip; localized head slip with complete thread slip; complete head slip with localized thread slip; and complete head slip with complete thread slip. The nut rotation can cause a reduction of the bolt tension too. Plain washers and spring washers are used to prevent loosening of bolted joints. However, it is important to know the performance of various types of washers in bolted joints. In the first paper, "The Role of Washer in Prevention of Failure of Bolted Joints Subjected to Dynamic Shear Loading: An Experimental and Analytical Study", the authors, Abhay Kakirde and Shriram Dravid, have experimentally investigated the loosening of bolted joints to analytically establish the role of the washer in controlling loosening failures of bolted joints subjected to dynamic loading. The influence of the process parameters-number of load cycles and pretension value on the loosening angle-was investigated for pretension/torque values ranging from 20 N-m, 22.5 N-m and 25 N-m, number of load cycles ranging from 30,000 to 300,000 cycles, using statistical analysis for three conditions of no washer, plain washer and spring washer. The results were presented in terms of slackening/loosening angle with respect to torque/pretension and load cycles. The results are useful in understanding the role of type of washer in the prevention of loosening of the bolted joint.

Earth tube heat exchanger also known as Earth Air Heat Exchanger (EAHE) is designed to effectively reduce energy consumption. The heat exchangers have an inherent relationship with the surrounding environment, and exchangers can cool or heat the ventilation air using cold or heat accumulated in the soil. They depend on the natural contrast between ambient air temperature and subsurface temperature. It is a well-known fact that while ambient temperatures are subject to daily fluctuations and temperature of the soil, i.e., Earth's Undisturbed Temperature (EUT) beyond a depth of, say, 2 to 3 m remains virtually constant throughout the year. The difference of about 7 oC and 12 oC remains higher than ambient air temperature in winter and lower than ambient air temperature in summer. The choice of the characteristic dimensions of the tube and the depth to which it is laid plays an important role in determining the characteristic dimensions of the EAHE in such a way that optimal thermal effectiveness is reached with acceptable pressure loss, to derive the actual heat that can be dissipated. They observed that EAHE can be used in place of air-conditioning system for better results in summer. In the paper, "Design of Earth Tube Heat Exchanger for Thermal Comfort in Residential Buildings", the authors, V N Mane and D V Ghewade, have presented the performance characteristics of EAHE systems in the case of Kolhapur region for a specific case of decreasing the room temperature from 32 oC to 26 oC. The authors have considered the cooling load requirement, the convection mode of heat transfer (between tube and air) and electrical analogy of heat conduction (heat transfer between tube and earth) to derive the actual heat that can be dissipated. The work explored the seasonal sensitivity of EAHE systems to variations in the temperatures at Kolhapur region.

Energy storage devices are very critical electrical components used in many locomotives. The devices consist of electrical parts which are covered with insulated sheet of polypropylene and are made up of AISI 1040 steel cases or boxes with ER 70S-6 as filler material and closed with Metal Inert Gas (MIG) welding. MIG welding, also referred to as Gas Metal Arc Welding, is a process that involves a wire being constantly fed through a welding gun at a steady pace. MIG welding is affected by welding current, voltage, electrode feed rate, gun travel speed and geometry of the weld or height of reinforcement or throat thickness. In the case of the storage devices, due to exposure to high voltage of about 5 KV, SF6 gas exerts tensile force on the butt welding of the case; and due to the bulging effect in these boxes, the welded joint breaks. In the paper, "An Analytical and Experimental Investigation of Welded Joint Strength for Energy Storage Devices", the authors, Saurabh Gandhe, V S Aher, V D Wakchaure, Ingole M W and Surve S M, have carried out an investigation to optimize the values of variables and effect of throat thickness of weld joint by observing the leakage test under high voltages. They have concluded that 5 mm throat thickness design was safe with a minimum bulging of 4 mm, which is very less in comparison, and there is no failure of the welded joint with applied voltage of 7,500 V.