Abstract: Impregnation of pores of porous silicon (PS) by Lanthanum Fluoride (LaF₃) using a novel one-step chemical bath technique, and application of the LaF₃-impregnated porous silicon (PS) structure (LaF₃/PS) as a potentiometric fluoride ion sensor have been investigated in this article. The impregnation of LaF₃ inside the pores of porous silicon was achieved using a chemical bath technique developed by this group. The Scanning Electron Microscopy (SEM) and EDX on the cross-section of LaF₃/PS/Si structure confirmed the LaF₃ film deposition inside the pores of PS. The heterostructure of LaF₃/PS/Si was investigated as fluoride ion (F^-) sensor in aqueous medium. The high specific area of PS was taken as the key subject to investigate the high fluoride sensitivity of the LaF₃/PS structure in aqueous medium. When experimented with home made fluoride solution having various concentrations the annealed LaF₃/PS/Si structure was found to detect the fluoride ion in aqueous solution. Its response was found linear in the fluoride concentration range of 2.28~4.28 pF. As capacitive sensor the overall fluoride sensitivity was found to be over-Nernstian (400 mV/pF). The experimental results indicate that LaF₃-impregnated porous silicon structure (LaF₃/PS) can be used as a high-sensitive fluoride-ion sensor in aqueous medium.

Abstract: A Wireless sensor network (WSN) is a collection of tiny sensor nodes that are deployed to monitor the environment. These sensor nodes have limited capabilities, especially the energy reserve and processing ability. So, the routing protocols design for this kind of networks is a crucial challenge. Because these routing protocols should be simple, energy-efficient, and robust to deal with a very large number of nodes, they should also be self-configurable to node failures and changes of the network topology dynamically. The most proposed routing techniques organize the network in clusters where the sensing area is divided into many sub-areas. This paper presents a new algorithm for clustering in WSN based on the node residual energy compared to the network one and allowing a better partitioning of the network area which enhance the data distortion at the sink by using the best data coding rate at the cluster head. The simulation results show that this algorithm allows network stability extension compared to the most known clustering algorithm.

Abstract: Measuring piston crown temperature and pressure during engine development cycle is paramount. This paper presents a new development in short distance telemetry system which includes an on board power generation device. A mechatronic data acquisition system is developed whereby signal conditioning is performed by a module inside the piston and the signal passed to a Bluetooth transmitter module for wireless telemetry to a Bluetooth receiver located in very close proximity, connected to an external host PC. The Data Acquisition Bluetooth module integrates a microcontroller that reads the conditioned sensor signal and performs any other required functionality. The microcontroller firmware includes a server that collates the data and transmits them via Bluetooth to the host PC to display via a client interface. An independent power supply consisting of a rotor incorporating NdFeB magnets and a wire wound stator. As the crankshaft rotates the rotor induces an AC voltage into the stator. A rectifying circuit converts the AC voltage into a regulated DC output voltage that drives the signal conditioning and embedded Bluetooth circuits.