sybil attacks pose a serious threat for wireless sensor networks (wsn) security. they can create problems in routing, voting schemes, decision making, distributed storage and sensor re-programming. in a sybil attack,the attacker masquerades as multiple sensor identities, that are actually controlled by one or a few existing attacker nodes. sybil identities are fabricated out of stolen keys, obt...

in this study, a specific ch4 sensor is fabricated based on interdigitated electrode that modified with core-shell of tungsten carbide/tin oxide (wc/sno2) nanoparticles by wet chemical method in different percents of carbon and tungsten. the morphology of wet chemical-synthesized wc/sno2 core-shell was evaluated by different methods such as patterned x-ray diffraction (xrd), and particle size a...

urease was immobilized on platinum electrode both by chemical binding and electropolymerization.the conductometric urea biosensor thus prepared showed a detection limit of 4.9×10-5 m and linear dynamic range from 4.9×10-5 to 5.8×10-3 m for urea concentration when the enzyme is covalently immobilized on pt electrodes. conductometric transducers respond to the changes in ionic strength thereby le...

............................................................................................................................... ii ACKNOWLEDGEMENT ......................................................................................................... iii List of Abbreviations.....................................................................................vii LIST OF Figures .................

This paper gives a state-of-art of wireless sensor network (WSN) technologies and solutions applied to precision agriculture (PA). The paper first considers applications and existing experiences that show how WSN technologies have been introduced in to agricultural applications. Then, a survey in hardware and software solutions is related with special emphasis on technological aspects. Finally,...

In Wireless Rechargeable Sensor Networks, one or more special mobile entities (called the Mobile Chargers) traverse the network and wirelessly replenish the energy of sensor nodes, using wireless power transfer technology. In this paper, we present some state of the art algorithms that apply to characteristic problems in such networks, namely efficient use of wireless power transfer using i) on...