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Polyaniline (PANI)/Ag nanocomposites were prepared by separate synthesis of silver nanoparticles by inert gas condensation, incorporating in the 1-methyl-2-pyrrolidinone (NMP) solution of polyaniline emeraldine base (PANIEB) and then cast into films at 120 °C. X-ray diffraction confirmed the presence of ∼67 nm silver nanoparticles in the polyaniline matrix. From the thermogravimetric analysis it is observed that the nanocomposite films have a higher degradation temperature than the pure PANI film. Scanning electron microscopy showed a uniform distribution, with spherical and granular morphology for low concentration of Ag nanoparticles, whereas for higher concentration (1.0% Ag) nanorods are formed. The impedance spectroscopic studies of NMP plasticized nanocomposite films suggest microphase separation into reduced and oxidized repeat units. Incorporation of silver nanoparticles in PANI reduces the charge trapping centres and increases the conducting channels, which causes a tenfold decrease in the real part of impedance.

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Effective transportation status surveillance imposes critical challenges for the Intelligent Transportation System (ITS) design. In this paper, the microscopic congestion detection protocol (MCDP) is proposed to make the vehicle-to-vehicle (V2V) communication capable of monitoring vehicle density and identifying traffic jam. By introducing transportation control domain in the existing network protocol header, each vehicle can count its neighbors and estimate the time spacing among vehicles. MCDP provides an infrastructure-less solution to the estimate of vehicle density, flow, and average velocity in a microscopically manner. Moreover, the safety speed limit is introduced to make each vehicle calculate its time to cover the intervehicle distance, such that every vehicle is able to assess the transportation congestion by comparing with some predefined safety time threshold. Monte Carlo simulations of the MCDP over four typical Chinese highways are presented to compare the MCDP scheme with the existing GreenShield congestion detection scheme. In addition, real road traces generated by SUMO over NS2 are utilized to show the achieved performance in terms of throughput, end-to-end delay, and packet delivery rate (PDR) in comparison to DSR and AOMDV in IEEE 802.11p and IEEE 802.11ac scenarios. On the basis of all the results, we conclude that MCDP is an inexpensive transport congestion detection technique for Vehicular Ad Hoc Networks (VANETs).

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We report synthesis of bismuth sulfide (Bi2S3) via conventional solid state reaction method at low temperature ∼150 °C and ambient pressure. X-ray diffraction analysis confirmed the orthorhombic phase of prepared material. Transmission electron microscope images revealed the formation of nanorods having diameter ∼20 nm and length ∼100 nm to ∼150 nm. Impedance and modulus plane plots from 20 Hz to 2 MHz show presence of bulk and grain boundary phases in Bi2S3 at each measurement temperature from 310 K to 400 K. An equivalent circuit model comprised of two resistance–R and constant phase element-Q (RQ) loops in series explains the electrical parameters (resistance and capacitance) and relaxation processes coupled with grains and grain boundaries. The conduction in Bi2S3 obeyed adiabatic small polaron hopping model. High and temperature dependent dielectric constant was observed in Bi2S3 suggesting it as an efficient material to be used in capacitive energy storage devices.

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