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Deceleration characteristics of vehicles are important for intersection design, deceleration lane design, traffic simulation modeling, vehicular emission and fuel consumption modeling, etc. Heterogeneous traffic stream consists of vehicles with wide variation in their physical dimensions, weight to power ratio and dynamic characteristics, which affect their deceleration behaviour. Majority of past studies are restricted to deceleration behaviour study of cars and trucks in homogenous traffic. Present study aims to analyze the deceleration behaviour of different vehicles types (like truck, car, motorized two and three-wheeler) on Nagpur-Mumbai Express Highway at Wardha, India. Drivers were asked to decelerate their vehicles from their maximum speed to zero speed in shortest time and their speed profiles are collected using Global Positioning System. Deceleration behaviour of different vehicle types is significantly different. Vehicles with higher maximum speed have higher deceleration time, deceleration distance, maximum and mean deceleration rates during their deceleration manoeuvre. In deceleration manoeuvre, vehicle's deceleration rate initially increases, attains the maximum deceleration and decreases afterwards. A dual regime model is developed to describe deceleration behaviour over entire speed range of all vehicle types except car. For car, a second order polynomial is proposed.

Pollution from vehicles is due to discharges like Carbon monoxide (CO), Carbon dioxide (CO 2), Hydrocarbon (HC) and Oxides of Nitrogen (NOx) through their tailpipe. Cars, being in dominant proportions (36.5%) in Indian traffic stream with small cars above 50% in total car proportions, are the main contributors to pollutants. Literature reveals that all factors being constant, at signalized intersection, car emission rates are the function of speed and acceleration. Since it is difficult to collect speed and position data at the actual intersection, this study is conducted on link road between National Highway 31 and IIT Guwahati, India, replicating the queue leader at signalized intersection. Tailpipe emissions are measured using onboard emission measurement system and speed and position data are measured using GPS device. Study illustrates that tailpipe emissions like CO, HC and NO x are sensitive to vehicle speed at similar acceleration level. Tailpipe emission rate initially decreases with increase in speed and then increase afterwards with further increase in speed, at similar acceleration level. Emission rates are found to increase with increase in vehicle acceleration rate. It was observed that deceleration does not influence tailpipe emission of small cars.

Pyrochlore phosphors have shown their worth in modern day lighting in the last few years. Colour tunability of the phosphor is one of the modern techniques used to obtain white light‐emitting diodes (WLEDs). In the proposed work, Y2Zr2O7:Sm3+,Eu3+ phosphors were investigated for WLED applications as well as display devices. A convectional solid‐state diffusion method was used to synthesize the proposed phosphors. X‐ray diffraction of the proposed phosphors was performed and compared with the standard Inorganic Crystal Structure Database. The crystal structure of the sample was cubic in nature, obtained from Rietveld refinement. Vibrational and morphological studies on the samples were carried out using Fourier transform infrared spectroscopy and scanning electron microscopy analysis. The photoluminescence study of the colour tunable phosphor showed the characteristic peak of Sm3+ together with the two sharp peaks of Eu3+ ions. Greenish yellow to red colour tunability was observed in the proposed phosphor with enhancement of Eu3+ ions. All these results showed the worth of this sample for WLEDs applications as well as in display devices.

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