Nonlinear magnetoinductive transmission lines

Power transmission in one-dimensional nonlinear magnetic metamaterials driven at one end is investigated numerically and analytically in a wide frequency range. The nonlinear magnetic metamaterials are composed of varactor-loaded split-ring resonators which are coupled magnetically through their mutual inductances, forming thus a magnetoiductive transmission line. In the linear limit, significant power transmission along the array only appears for frequencies inside the linear magnetoinductive wave band. We present analytical, closed form solutions for the magnetoinductive waves transmitting the power in this regime, and their discrete frequency dispersion. When nonlinearity is important, more frequency bands with significant power transmission along the array may appear. In the equivalent circuit picture, the nonlinear magnetoiductive transmission line driven at one end by a relatively weak electromotive force, can be modeled by coupled resistive-inductive-capacitive (RLC) circuits with voltage-dependent capacitance. Extended numerical simulations reveal that power transmission along the array is also possible in other than the linear frequency bands, which are located close to the nonlinear resonances of a single nonlinear RLC circuit. Moreover, the effectiveness of power transmission for driving frequencies in the nonlinear bands is comparable to that in the linear band. Power transmission in the nonlinear bands occurs through the linear modes of the system, and it is closely related to the instability of a mode that is localized at the driven site.Comment: 11 pages, 11 figures, submitted to International Journal of Bifurcation and Chao

Noise induced breather generation in a sine-Gordon chain

International audienceWe consider a sine-Gordon chain driven sinusoidally at one end. In the absence of noise, there exists a well known critical value of the amplitude beyond which breather modes can be generated via the phenomenon of supratransmission. We consider values of the driving amplitude below the critical amplitude such that no breather propagates in the medium. We show that noise induces breather generation with a given probability depending on the noise intensity. We also propose a bifurcation diagram which extends the supratransmission effect to a more realistic signal, namely a noisy sinusoidal excitation. We finally discuss some promising signal processing applications that can be developed by taking into account the contribution of noise in the media sharing this supratransmission phenomenon

Regular Geometrical Languages and Tiling the Plane

International audienceWe show that if a binary language L is regular, prolongable and geometrical, then it can generate, on certain assumptions, a p1 type tiling of a part of ℕ2. We also show that the sequence of states that appear along a horizontal line in such a tiling only depends on the shape of the tiling sub-figure and is somehow periodic

Formal Development of Multi-Purpose Interactive Application (MPIA) for ARINC 661

International audienceThis paper reports our experience for developing Human-Machine Interface (HMI) complying with ARINC 661 specification standard for interactive cockpits applications using formal methods. This development relies on the FLUID modelling language, we have proposed and formally defined in the FORMEDICIS project. FLUID contains essential features required for specifying HMI. To develop the Multi-Purpose Interactive Applications (MPIA) use case, we follow the following steps: an abstract model of MPIA is written using the FLUID language; this MPIA FLUID model is used to produce an Event-B model for checking the functional behaviour, user interactions, safety properties, and interaction related to domain properties; the Event-B model is also used to check temporal properties and possible scenario using the ProB model checker; and finally, the MPIA FLUID model is translated to Interactive Cooperative Objects (ICO) using the PetShop CASE tool to validate the dynamic behaviour, visual properties and task analysis. These steps rely on different tools to check internal consistency along with possible HMI properties. Finally, the formal development of the MPIA case study using FLUID and its embedding into other formal techniques, demonstrates reliability, scalability and feasibility of our approach defined in the FORMEDICIS project

Plant addition impact on aflatoxin B1

Aflatoxin B1 is a mycotoxin that can be present in peanut-based products, such as fried peanut biscuits, if Good Agricultural Practices are not respected. Impact of plant powder presence on aflatoxin B1 levels was investigated in contaminated peanut biscuits. It was observed that adding 2% of Moringa oleifera powder led to a significant (p < .05) reduction of the toxin after 3 hr of contact time in the dough before the frying step. The toxin level reduction was estimated at 17%. The addition of moringa powder can also have some nutritional benefits. It doubled the content of iron and calcium in the biscuits, leading to products that could bear a claim “source of” for 100 g of biscuits. There was almost no loss of those minerals during the frying step. β-carotene content is a nutrient present in moringa powder, unfortunately the losses during the frying step were estimated at 78%, probably due to the molecule migration from the biscuit to the frying bath. Adding 2% moringa powder in fried peanut biscuit could present safety and nutritional benefits, however, consumer acceptance should be studied as the color as well as the peanut smell and flavors were significantly impacted (p < .05). It is recommended to pursue the investigation of the role of moringa powder onto the toxin degradation to understand the mechanism behind and assess the toxicity of the secondary molecules generated