In this paper, we propose a new method for Bulk waves detection of an acoustic microwave signal during the propagation of acoustic microwaves in a piezoelectric substrate (Lithium Niobate LiNbO₃). We have used the classification by probabilistic neural network (PNN) as a means of numerical analysis in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the Bulk waves easily. These singularities inform us of presence of Bulk waves in piezoelectric materials.

La conception, le développement et l'évaluation des performances thermiques d'un cuiseur solaire boîte trapèze à surface réceptrice inclinée (CSBSRI) est présenté dans le présent article. Une chaîne d'acquisition de données équipée de divers instruments de mesure est installée pour le contrôle du système. Les profils thermiques des différentes composantes du cuiseur ont été mesurés au site saharien de Ghardaïa pour différentes conditions climatiques durant la saison hivernale et estivale. L'analyse des performances du cuiseur solaire est évaluée au moyen de la puissance de cuisson ajustée, qui ; se situant dans l'intervalle des Normes du Standard de Funk, met le cuiseur réalisé dans la gamme des Standards Internationaux. Les tests expérimentaux entrepris démontrent que le cuiseur proposé, avec une surface d'ouverture inclinée ; améliore considérablement les performances thermiques du cuiseur solaire, il est de ce fait adapté à la cuisson des aliments en été et en hiver où la hauteur du soleil est faible.

In Algeria, Opuntia ficus-indica production is important. This seasonal fruit is a characteristic of arid and semiarid regions. Taking into account its high content in antioxidants, it has an excellent nutritional value. The aim of this research is the prickly pear morphological and physicochemical characterization study, which is widely present in the Arris (Batna, Algeria) area. The results of this experimental study are comparative to those of the same species from other world regions. The whole fruit weight is estimated to reach 63.38 g with a juice ratio of 71.42 %, a pH of 5.54, moisture of 89.3 % and a brix of 10.4 %. The quantitative amount of the phenolic compounds of the fruit revealed contents of 45.70 mg GAE / 100 g of MF for total polyphenols.

The complexity of systems in the current process industry is conducive to the concerns of industrialists about the risks that may be inherent in these systems. Risk reduction measures should be considered and implemented to reduce the initial risk to an acceptable level. This is usually achieved by using a combination of systems that provide security, inter alia, Safety Instrumented Systems (SIS). The implementation of a SIS requires the determination of its Safety Integrity Level (SIL) which it must have in order to attain the tolerable risk. The standards IEC 61508 and 61511 provide a framework for the determination of SIL and propose different methods. The objective of this work consists in proposing an approach of allocation and optimization of the security barriers, using the methods of risk graph and LOPA (Layer Of Protection Analysis) In order to evaluate the performance of the safety measures put in place for the control of risks in a hydrocarbon storage station. A cost benefit analysis (CBA), as a decision support tool, is carried out to improve the safety level of the process studied.