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The industrial systems are recently leaning towards every possible means of automation for enhanced accuracy and better time management. But in case of developing countries like Bangladesh, the development of such sophisticated systems is not always cost effective for the manufacturers. Keeping this idea in mind, an initiative was taken to design and fabricate a low cost group of robotic guided vehicles to perform logistics in a quasi -industrial environment. The group consisted of two robotic vehicles those were capable of carrying certain loads and supply them to a predefined unloading location. An imaginary industrial environment was prepared in the laboratory and the robots went through several successful test runs which validated the efficiency and capability of the prototypes. The robots were prepared mostly with locally available materials and technology to reduce the expenditure. The manufacturing process also covered the use of appropriate technology. Both the robots were microcontroller operated and were re-programmable for introducing the possible changes those could happen in the industrial environment. The test runs were performed by programming them for maneuvering through both linear and curved trajectories. They consisted of tactile sensor feedback control to refine their positions in the destinations and deliver the load in an accurate orientation. The research proved the possibility of developing Automated Guided Vehicle Systems (AGVS) for the logistics purposes of local industries within a moderate cost limit.

A spherically expanding flame in a quiescent premixture is a bifurcation phenomenon, in which the flame becomes unstable at a radius, greater than some critical value, while remaining stable below that critical radius. Beyond this critical radius, developing instabilities are initiated by propagating cracks to form a coherent structure covering the entire flame surface and the flame accelerates. The present paper reports a Schlieren photographic study of spherical flame propagation in methane—air, iso-octane—air and n-heptane—air premixtures at different initial conditions where the onset of instability and the flame acceleration are clearly perceived. Critical size and corresponding elapsed time for the development of such instability are measured and these values are correlated with the appropriate flame parameter.