Enhancement of the Traffic Differentiation Architecture for WBAN Based on IEEE 802.15.4

In the healthcare domain, Wireless Body Area Network has emerged as a vital technology that is capable of providing better methods to diagnose various hazardous diseases. The CANet projet is a project that proposes alternative monitoring solutions. This paper studies the possibility of transmitting different types of information through an IEEE 802.15.4 MAC layer that not supports the transmission of heterogeneous information. We have proposed an extension to the MAC layer which makes possible the transmission of various information types. This solution designed by “diffrentiation layer” uses a purge function to ensure the use of CAP and CFP by the same node in the same superframe and allows the differentiation between several information. Our results show that our solution is reliable under worst-case.     

Mechanical thinning to make few-layer graphene from pencil lead

Simple, fast and low cost production of graphene and few-layer graphene (FLG) with high yield is presented. The synthesis consists of mechanical ablation of pencil lead on a harsh glass surface with simultaneous ultrasonication followed by a purification to remove the inorganic binder present in the pencil lead. The combination of several characterization techniques, i.e. SEM, TEM and Raman show that FLG with lateral size of few micrometers, consisted of 1 up to 20 and occasionally up to fifty sheets is obtained by this process.     

Global behaviour of a composite stiffened panel in buckling. Part 2: Experimental investigation

The present study analyses an aircraft composite fuselage structure manufactured by the Liquid Resin Infusion (LRI) process and subjected to a compressive load. LRI is based on the moulding of high performance composite parts by infusing liquid resin on dry fibres instead of prepreg fabrics or Resin Transfer Moulding (RTM). Actual industrial projects face composite integrated structure issues as a number of structures (stiffeners, …) are more and more integrated onto the skins of aircraft fuselage.A post-buckling test of a composite fuselage representative panel is set up, from numerical results available in previous works. Two stereo Digital Image Correlation (DIC) systems are positioned on each side of the panel, that are aimed at correlating numerical and experimental out-of-plane displacements (corresponding to the skin local buckling displacements of the panel). First, the experimental approach and the test facility are presented. A post-mortem failure analysis is then performed with the help of Non-Destructive Techniques (NDT). X-ray Computed Tomography (CT) measurements and ultrasonic testing (US) techniques are able to explain the failure mechanisms that occured during this post-buckling test. Numerical results are validated by the experimental results.     

LaCrO3–VO x –YSZ anode material for solid oxide fuel cells operating on H2S-containing syngas

The perovskite type lanthanum chromite LaCrO₃ has been synthesized by nitrate-citrate combustion method. Phase transformations have been studied by using simultaneous differential scanning calorimetry and thermogravimetric analysis. The bulk structure of LaCrO₃ as well as the catalyst have been examined by X-ray diffraction (XRD). The cell was made using LaCrO₃–VO _x –YSZ anode. Impedance measurements showed that the polarization resistance was much smaller when the fuel changed from pure H₂ to 5000 ppm H₂S balance H₂. The performance for 5000 ppm H₂S balance H₂ was much better than with pure H₂ as a result of a lower polarization resistance. At 900 °C the maximum power density was 463 mW cm⁻² when using H₂S-containing H₂ as fuel. The presence of H₂S in the syngas significantly decreased the polarization resistance and improved the fuel cell performance. At 900 °C the achieved power density was 214 mW cm⁻² for H₂S (5000 ppm)-containing syngas (40% CO + 60% H₂).     

Fabrication and characteristics of melt-spun Al ribbons reinforced with nano/micro-BN phases

Melt-spun aluminum ribbons with up to 5 wt.% of embedded nano/micro boron nitride (BN) phases, namely multiwalled BN nanotubes (BNNTs) or BN microparticles (BNMPs), were fabricated by melt-spinning in an argon atmosphere. The comparative structural characteristics were analyzed using X-ray diffraction, scanning and transmission electron microscopy, and internal friction measurements as a function of temperature within an 80–800 K range. Room temperature tensile tests were carried out on ribbons. These revealed reinforcing effects on pure Al-matrices after nano/micro-BN embedment for both added phases with the notably higher numbers peculiar to the BNNT-containing samples. The intrastructural interactions between BN additions and Al-matrices are discussed based on the structural analysis and the internal friction data.     

Ethanol aus Biomasse als zukünftiger Kraftstoff für Automobile

Ethanol from Biomass as a Future Fuel for Automobiles. Methanol and ethanol seem to be the most attractive mid-term candidates for future application as fuels for automobiles. For countries having coal, natural gas or wood recources methanol will be the most optimal solution, where as in countries having excellent conditions for plant material cultivation, ethanol will become the fuel of the future. The production routes for methanol from coal, natural gas and mussicipal waste has been discussed very often. However, upon the production of ethanol from plant material, so-called biomass, just limited information is available. From the point of view of the motor car industry the potential of biotechnology for the production of ethanol as automobile fuels is discussed.