The strength of the composite deck slab depends mainly on the longitudinal shear transfer mechanism at the interface between steel and concrete. The bond strength developed by the cement paste is weak and causes premature failure of composite deck slab. This deficiency is effectively overcame by a shear transferring mechanism in the form of mechanical interlock through indentations, embossments, or fastening studs. Development of embossment patterns requires an advanced technology which makes the deck profile expensive. Fastening studs by welding weakens the joint strength and also escalates the cost. The present investigation is attempted to arrive at a better, simple interface mechanism. Three types of mechanical connector schemes are identified and investigated experimentally. All of the three shear connector schemes exhibited full shear interaction with negligible slip. The strength and stiffness of the composite slabs with shear connectors are superior about one and half time compared to these of the conventional reinforced concrete slabs and about twice compared to these of composite slabs without mechanical shear connectors. The scheme2 and scheme3 shear connector mechanisms integrate deck webs and improve strength and stiffness of the deck, which can effectively reduce the cost of formworks and supports efficiently.

In recent years, there is growing interest in hybridisation of military vehicles due to the features and advantages offered by the technology. Generally, the hybrid electric vehicle (HEV) is propelled by a combination of electric motors and internal combustion engine (ICE). Hybrid electric combat vehicles, when compared with conventional vehicles, have the advantages of improved fuel efficiency and drivability due to optimal operation of ICE, regenerative braking and silent operation capability. Limitations related to key technologies such as compact electric motors/generators, power electronics and energy storage systems that are required to operate under extreme environmental conditions pose challenges to the development of hybrid electric power pack. Technical challenges of HEV technologies considering futuristic applications of combat vehicles is described. The configuration specification of hybrid electric power train architecture suited to deliver high automotive performance and power demands for infantry combat vehicles (ICV) is also discussed.

NomeNclatureA Distance between sprocket to CG W Gross vehicle weight in N INtroDuctIoNMain battle tank (MbT) Forms the backbone of the mechanised forces for any conventional army. Traditionally these platforms were designed keeping in mind the conventional warfare philosophy or the iron triangle of firepower, mobility and protection. Such an iron triangle underwent minor changes with the introduction of un-conventional warfare by non-state actors post 1 9/11. Hence, the conventional design philosophy based on contemporary threat scenario needs to be modified or incorporated with fresh threats in order to extrapolate it as a future combat scenario. One such future combat scenario is as shown in Fig. 1. This threat scenario forms the baseline for arriving at the configuration for the generation next main battle tank (GNMbT). However, the dilemma facing designers of such GNMBT is whether to arrive at a configuration which is evolutionary or revolutionary in nature.An evolutionary approach per se is an extension of an existing platform with add-ons or technology upgrades so that contemporary threats are addressed. Examples for such an approach include Arjun (Mk-I and Mk-II), Challenger (1,2 and TES), M1 Abrahms (A1 and A2), Leopard 2 (A1 to A7+) etc. On the other hand, the alternate approach includes arriving at an altogether new configuration which not only addresses the future threats but also truly revolutionary in configuration and design. Design Configuration of a Generation Next Main Battle Tank for Future Combat ABsTrACTThe future combat scenario will undergo a sea change as compared to the conventional and un-conventional warfare employed by the traditional armies and non-state actors. In such a scenario, the main battle tank which serves as a game changer during these conflicts has to face the dilemma whether its design should be either evolutionary or revolutionary. To determine the basis of selecting the right type of design based on the above, the broad parameters that define the configuration namely number of crew, weight, armament system, survivability, operating range, transportability, tactical mobility, trafficability, intelligence -surveillance -target acquisitionreconnaissance (ISTAR), system modularity and theatre of operation have been considered. Taking these parameters into account, this study evaluates both the evolutionary and revolutionary design configurations for a generation next main battle tank. Finally, from the outcome of this study it is observed that the revolutionary design approach not only fares better compared to the evolutionary approach, but also possess ease of adaptiveness as an universal combat weapon platform.

No abstract

The aim of the study was to recover copper and lead metal from waste printed circuit boards (PCBs). The electrowinning method is found to be an effective recycling process to recover copper and lead metal from printed circuit board wastes. In order to simplify the process with affordable equipment, a simple ammonical leaching operation method was adopted. The selected PCBs were incinerated into fine ash powder at 500°C for 1 hour in the pyrolysis reactor. Then, the fine ash powder was subjected to acid-leaching process to recover the metals with varying conditions like acid-base concentration, electrode combination, and leaching time. The relative electrolysis solution of 0.1 M lead nitrate for lead and 0.1 M copper sulphate for copper was used to extract metals from PCBs at room temperature. The amount of lead and copper extracted from the process was determined by an atomic absorption spectrophotometer, and results found were 73.29% and 82.17%, respectively. Further, the optimum conditions for the recovery of metals were determined by using RSM software. The results showed that the percentage of lead and copper recovery were 78.25% and 89.1% should be 4 hrs 10 A/dm2.