The Synchronous Approach to Designing Reactive Systems

Synchronous programming is available through several formally defined languages having very different characteristics: Esterel is imperative, while Lustre and Signal are declarative in style; Statecharts and Argos are graphical languages that allow one to program by constructing hierarchical automata. Our motivation for taking the synchronous design paradigm further, integrating imperative, declarative (or dataflow), and graphical programming styles, is that real systems typically have components that match each of these profiles. This paper motivates our interest in the mixed language programming of embedded software around a number of examples, and sketches the semantical foundation of the Synchronie toolset which ensures a coherent computational model. This toolset supports a design trajectory that incorporates rapid prototyping and systematic testing for early design validation, an object oriented development methodology for long term software management, and formal verification at the level of automatically generated object code.     

Ligand‐Free Synthesis of Aluminum‐Doped Zinc Oxide Nanocrystals and their Use as Optical Spacers in Color‐Tuned Highly Efficient Organic Solar Cells

The color of polymer solar cells using an opaque electrode is given by the reflected light, which depends on the composition and thickness of each layer of the device. Metal‐oxide‐based optical spacers are intensively studied in polymer solar cells aiming to optimize the light absorption. However, the low conductivity of materials such as ZnO and TiO₂ limits the thickness of such optical spacers to tenths of nanometers. A novel synthesis route of cluster‐free Al‐doped ZnO (AZO) nanocrystals (NCs) is presented for solution processing of highly conductive layers without the need of temperature annealing, including thick optical spacers on top of polymer blends. The processing of 80 nm thick optical spacers based on AZO nanocrystal solutions on top of 200 nm thick polymer blend layer is demonstrated leading to improved photocurrent density of 17% compared to solar cells using standard active layers of 90 nm in combination with thin ZnO‐based optical spacers. These AZO NCs also open new opportunities for the processing of high‐efficiency color tuned solar cells. For the first time, it is shown that applying solution‐processed thick optical spacer with polymer blends of different thicknesses can process solar cells of similar efficiency over 7% but of different colors.     

Modelling of through silicon via and devices electromagnetic coupling

This paper is essentially composed of two parts for future synthesis. We developed 2D and 3D simulations, starting from a 0.35 μm standard CMOS technology, focusing on through silicon via or redistribution layer induced coupling; nMOSFET, pMOSFET, and the sensitive regions of the CMOS inverter are investigated. We also study stacked devices in 3D circuits, in the radiofrequency range, and propagation of electromagnetic waves along some interconnections with discontinuities. This study is performed in the time domain—a finite-difference time-domain method is applied to the analysis of some vias flanked by two striplines, all embedded in silicon. Electric and magnetic field distributions, transmission and reflexion parameters, and pulse propagations along a transverse via are presented.     

First-principles study of nickel-silicides ordered phases

We present a study of nickel-silicides ordered alloys by means of first-principles calculations. Emphasis was put on the phases (low and high temperatures) identified in the binary phase diagram, namely: Ni₃Si-β₁, -β₂, and -β₃, Ni₃₁Si₁₂-γ, Ni₂Si-δ, -θ, Ni₃Si₂-?, NiSi-MnP and NiSi₂-α. In addition, some common structures are computed for information: L1₂, D0₃ and D0₂₂. The simulations reproduce with a high accuracy lattice parameters and formation energies of main experimental structures, except for β₂ and β₃. Our results clarify the crystallographic nature of the γ structure, and the comparison of experimental Raman spectra and vibrational calculations will help experimentalists to identify without ambiguity NiSi₃ structures.     

Validation of two tropical marine bivalves as bioindicators of mining contamination in the New Caledonia lagoon: Field transplantation experiments

The bioaccumulation and retention capacities of some key local contaminants of the New Caledonia lagoon (Ag, As, Cd, Co, Cr, Cu, Mn, Ni and Zn) have been determined in the oyster Isognomon isognomon and the edible clam Gafrarium tumidum during transplantation experiments. In a first set of experiments, oysters and clams from a clean site were transplanted into contaminated sites. Uptake kinetics determined in the field indicated that for Cr and Cu in oysters and Co, Ni, and Zn in clams, concentrations in transplanted bivalves reached those of resident organisms after 100d, whereas for the other elements, it would require a longer time for transplanted bivalves to reach the same levels as in the resident populations (e.g., up to 3 years for Cd). However, the slow uptake rate for metals observed in the latter transplantation is rather related to low bioavailability of metals at the contaminated sites than to low bioaccumulation efficiency of the organisms. Indeed, results of a second transplantation experiment into two highly contaminated stations indicated a faster bioaccumulation of metals in both bivalves. Results of both transplantations point out that the clam G. tumidum is a more effective bioindicator of mining contamination than I. isognomon, since it is able to bioaccumulate the contaminants to a greater extent. However the very efficient metal retention capacity noted for most elements indicates that organisms originating from contaminated sites would not be suitable for monitoring areas of lower contamination. Hence, geographical origin of animals to be transplanted in a monitoring perspective should be carefully selected.     

Compressibility of carbon woven fabrics with carbon nanotubes/nanofibres grown on the fibres

Growth of carbon nanotubes (CNT) or carbon nano-fibres (CNF) on carbon fibrous substrates is a way to increase the fracture toughness of fibre reinforced composites (FRC), with encouraging results reported in the recent years. If these nano-engineered FRC (nFRC) are destined to leave laboratories and enter industrial-scale production, a question of adapting the existing composite manufacturing methods will arise. The paper studies compressibility of woven carbon fibre performs (two types of fabrics) with CNT/CNF grown on the fibres using the CVD method. The results include pressure vs thickness and pressure vs fibre volume fraction diagrams for one and four layers of the fabric. Morphology of the nFRC is studied with SEM. It is shown that the pressure needed to achieve the target fibre volume fraction of the preform increases drastically (for example, from 0.05 MPa to more than 0.5 MPa for a fibre volume fraction of 52%) when CNT/CNF are grown on it. No change in nesting of the fabric plies is noticed. The poor compressibility can lower the achievable fibre volume fraction in composite for economical vacuum assisted light-RTM techniques and increase the pressure requirements in autoclave processing.     

Combined microwave and enzymatic treatments for ��-lactoglobulin and bovine whey proteins and their effect on the IgE immunoreactivity

Effect of combined microwave (MW) and enzymatic hydrolysis on the human immunoglobulin E (IgE)-binding properties of ??-lactoglobulin (??-lg) and other whey proteins (WP) was investigated. Separated ??-lg and full whey protein isolate (WPI) were hydrolyzed with trypsin, chymotrypsin, mixture of trypsin/chymotrypsin, and pepsin at three microwave power levels: 50?W during 1 and 5?min, 100 and 200?W during 1 and 3?min. The immunoreactivity of the obtained hydrolysates resulting from combined microwave protease treatment was assessed using sera of young patients allergic to bovine whey proteins. The application of microwave treatment at 200?W enhances the hydrolysis of ??-lg by pepsin in 3?min and decreases significantly its immunoreactivity. The extensive hydrolysis of the microwave-treated ??-lg and WPI with trypsin, chymotrypsin, and the mixture of trypsin with chymotrypsin did not have an impact on the IgE binding of the products obtained in all the studied conditions.     

High energy dry coating mixing: Elements on velocities,temperatures and melting

In dry coating processes no liquid, solvent, binder or water, is required. This makes them advantageous compared to wet coating alternative: being low cost, no drying step required, environmentally friendly (no volatile organic compounds related problems) and simple in operation. But there is still a lack of fundamental knowledge of the implied mechanisms. Often the process itself has been empirically designed and is not always well characterized.In this work, some hydrodynamic elements are developed in a high energy mixer used for dry coating: the specific behavior of the Nara hybridizer NHS-0 is investigated. In the first part, recirculation velocities and temperatures are derived during the process, or when the purge is on. The effects of the pressure purge and of the rotor velocity on the purge and the effect of the rotation on the temperature increase are studied. In the second part, a simple experimental approach is carried out to derive qualitatively the local temperature inside the apparatus with the help of polymers with different melting temperatures. This approach illustrates a first step for dry coating application with waxes.     

Choice of a pertinent color space for color texture characterization using parametric spectral analysis

This article presents a comparison of different color spaces including RGB, IHLS and L?a*b* for color texture characterization. This comparison is based on the fusion of the independent spatial structure and color feature cues. In IHLS and L*a*b*, two channel complex color images are created from the luminance and the chrominance values. For such images, two dimensional complex multichannel linear prediction models are used to perform parametric power spectrum estimation and the structure feature cues are computed from this estimated power spectrum. Quantitative comparison of auto spectra of luminance and combined chrominance channels for different color spaces is done. This comparison is based on the degree of decorrelation between luminance and chrominance information provided by different color space transformations. Three dimensional histograms are used as color feature cues. Then, to classify color textures, Kullback-Leibler divergence based symmetric distance measures are calculated for pure color, luminance structure and chrominance structure feature cues. Individual as well as combined effect of information from all feature cues on classification results is then compared for different color spaces and different color texture data sets. The proposed color texture classification method performs better than the state of the art methods in certain cases. The L*a*b* color space gives us a better characterization of the chrominance spatial structure as well as the overall spatial structure for all of the chosen data sets. Experimental results on pixel classification of color textures are also presented and discussed.