The Nanostructure Zeolites MFI-Type ZSM5

The development of new porous solids begins to provide effective and original solutions to the problems of pollution and sustainable development, and the challenge is to discover new performance of these materials. Among these materials are zeolites; however, one type has retained the attention since its discovery in 1972; this is zeolite-type ZSM-5, because of their particular properties in many industrial processes. These porous solids are characterized on the atomic scale by the existence of pores, distributed regularly in the matter and are likely to accommodate in their structures, gases, liquids, and solids for trap or temporarily store them. Only the average porosity of these zeolites constitutes an obstacle to the catalysis of cumbersome molecules that are well branched. To deflect this inaccessibility factor and trying to find a solution to this steric hindrance, the attention of the researchers was focused on using the surface properties of ZSM-5. It is well known that the efficiency and selectivity of a porous catalyst depends on its textural and structural characteristics and more precisely on the number of locations active on the external surface and the number of locations accessible through the porous system. The nanocrystallinity in the field of zeolites can be defined as a situation in which the physicochemical properties are largely determined by a larger number of atoms in the outer limit of crystallite. In this chapter, the work of several researchers who synthesized the ZSM5 in the field of nanostructures is presented. We find that, despite the different methods of synthesis, however, the field of nanostructures ZSM5 has been achieved. Certain parameters such as the concentration of mineral agent, the concentration of the structuring agent, and the duration of aging have a direct influence on the crystal size of the zeolites obtained. Different characterizations were used to identify the purity and size of the nanocrystals ZSM5

Analyse Quantitative des Risques : Application sur les Bacs de Stockage

The liquefied petroleum gas is one area where catastrophic release scenarios are omnipresent. For this purpose, it is essential to implement preventive and protective safety barriers a high level of reliability, availability, maintainability and safety using in-depth quantitative risk analyzes, to ensure total control of these areas, and reducing the severity and frequency of occurrence of these catastrophic scenarios. This thesis exploit the principles of dependability, the probability laws as well as the different methods of Quantitative Risk Analysis. After establishing a state of the art on the application of Bayesian Belief Networks as a powerful and dynamic decision support tools in the Quantitative analysis, an expression on how to obtain probabilistic importance factors by Bayesian inference was highlighted. In order to give importance to this researcher work: an application on the water deluge system, one of the most important safety barriers installed in LPG storage areas, has been studied through modeling and simulation by the different methods of Analysis and probabilistic models such as: FMEA, Fault Tree Analysis, Monte Carlo Simulation, Binary Decision Diagram, Exponential Law, Weibull Law and Probabilistic Importance Factors. At the end of this work, a Bayesian Belief Network was developed to define the interaction between the criticality of the equipment’s and their impact on the unavailability of the system as well as the integration of expert opinions. This Bayesian Network has been used as a dynamic and efficient decision support tool for optimizing the performance of the studied system.La zone de stockage de gaz de pétrole liquéfié est l’une des unités de procédés ou les scénarios les plus catastrophiques sont omniprésents. A cet effet, il est primordial d’implémenter des barrières de sécurité préventives et d’intervention avec un haut niveau de fiabilité, disponibilité, maintenabilité et de sécurité suite à des analyses quantitatives approfondies sur les risques, afin de garantir une totale maitrise de ces zones, et réduire la gravité et la fréquence d’occurrence de ces scénarios catastrophiques. Cette thèse a tiré profit des principes de la sûreté de fonctionnement, les lois de probabilité ainsi que les différentes méthodes d’Analyse Quantitative des Risques. Après avoir établi un état de l’art sur l’application des Réseaux bayésiens comme étant un outil d’aide à la décision performent et dynamique dans l’analyse Quantitative, nous avons pu définir les équations nécessaires pour l’obtention des facteurs d’importance probabiliste par inférence bayésienne. Afin de mettre en évidence ce travail de recherche une application sur le système déluge à eau, l’une des barrières de sécurité la plus importante installée dans les zone de stockage de GPL, a été étudiée en passant par la modélisation et simulation par les différentes méthodes d’analyse et modèles probabilistes tel que : AMDE, Arbre de défaillance, Simulation de Monté Carlo, Diagramme de décision binaire, loi exponentiel, loi de Weibull et les facteurs d’importance probabilistes. A la fin de ce travail un Réseau Bayésien a été élaborer pour définir l’interaction entre la criticité des équipements et leurs impacts sur l’indisponibilité du système ainsi que l’intégration d’avis d’experts. Ce Réseaux Bayésien a été utilisé comme étant un outils d’aide à la décision dynamique et efficace pour l’optimisation des performances du système étudie

Reliability analysis by mapping probabilistic importance factors into bayesian belief networks for making decision in water deluge system

International audienceLiquid petroleum gas (LPG) is one area where catastrophic release scenarios have occurred. For this reason, preventive, and protective barriers have to be installed in order to reduce the occurrence and the severity of these scenarios. This article addresses an analysis of deluge system barrier and proposes a making decision process to ensure a high level of reliability, availability, maintainability, and safety (RAMS) using a robust Reliability Analysis with conditional probabilities. To achieve this RAMS target, a methodology for converting fault tree analysis (FTA) in continuous time using Monte Carlo (MC) simulation to Bayesian belief network (BBN) is developed. The probabilistic importance factors (PIFs) for critical components ranking and decision making are also mapped using BBN inferences in Water Deluge Systems (WDS) with an optimization aim using redundancy or maintenance tasks. This analysis illustrates the helpfulness of mapping PIFs into BBN for making a decision in any critical technological infrastructures

Textural properties of ZSM-5 nanocrystals prepared in alkaline potassium fluoride medium

International audienceIn this paper, we optimized the fluorine route in hydrothermal conditions under atmospheric pressurefor the synthesis of ZSM-5 crystals of controlled size. Several experimental parameters were varied forobtaining particles in the nanoscale range in the shortest time with the highest crystalline as well astextural properties. The 100% crystalline ZSM-5 crystals were obtained for a temperature of reaction of100◦C and a crystallization time of 7 days. The concentration of the organic template was found to greatlyinfluence the crystallization process. XRD showed that the best result was obtained for a TPABr/SiO2ratioof 0.4. Below this ratio, a slowdown of the crystallization process was observed. The increase of the molarratio template/silica above 0.4 induced an unfavourable increase of the alkalinity of the mixture. Thisresulted in a decrease of the crystal growth and consequently a decrease of the size of the zeolite crystals.In these conditions, the average diameter of the crystals was extended from 20 to 47 nm. Beyond 20 h, the ageing time had a little effect on the crystallinity of the final products, whereas the crystal size wasconsiderably reduced from 52 nm to less than 25 nm when the ageing time was increased from 20 to 44 h

Comparison of the evolution of physicochemical and microbial characteristics of the wastes, those most commonly generated in Algeria during composting

Purpose This paper focuses on monitoring the behavior of five different types of waste and humus during composting to see the impact of the nature of the substrate on the process and the quality of mature compost. Method Green waste, coffee waste, household waste (Fraction of the household waste which having dimensions smaller than 8 mm) and humus were collected separately from different areas of Oran city, western Algeria, composted in windrows of 2 m long, 1 m wide, and 0.5 m high each for 150 days during the winter and spring period (2019-2020). The physicochemical parameters and characteristics were determined on the one hand, and on the other hand, the evolution of the microflora was monitored. Results The results show a correlation between the parameters of each substrate. Furthermore, it was found that green waste, coffee waste, and household waste can give the best quality of compost if the process conditions are respected (maintenance of C/N ratio and moisture level). However, small waste and very small waste can also be used to amend green areas and public gardens. The results also showed that the concentration of pathogenic microorganisms such as Salmonella and Shigella did not exceed the NFU44-051 standard. Conclusion The findings support the industrialization of waste valorization by composting as an effective technique for waste reduction given the current situation and encourage investors and promote the industrialization of waste recovery by composting in Algeria

Study by AES and EELS spectroscopies of antimony and phosphorous evaporated on massive indium and on cleaned InP

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The behaviour of ternary compounds InGaAs and GaAsN subjected to electron irradiation.

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Le 1er séminaire international sur les innovations technologiques au service de l'agriculture durable (SIITA)

Le 1er Séminaire International sur les innovations technologiques au service de l'agriculture  durable a permit de faire le point sur un certain nombre de thématiques scientifiques en se basant sur les innovations technologiques au service de l'agriculture durable et ses impacts sur l'environnement et l'industrie. IL a regroupé des chercheurs universitaires nationaux et internationaux et des industriels pour discuter, sur les innovations et nouvelles tendances en matière de production, conservation et développement de l'agriculture. Elle a été également une occasion pour développer et renforcer la collaboration entre les chercheurs et les industriels en matière de recherche scientifique dans les domaines agriculture, agro-alimentaire et environnement. Le séminaire s'est décliné en en cinq thèmes: Thème 1: Histoire d'innovations technologiques dans l'agriculture ; Thème 2: L'innovation pour relever les défis de l'agriculture pour un développement durable; Thème 3: Innovation individuelles et collectives de toutes natures; Thème 4: Évaluation des innovations apportées par les agriculteurs dans l'exploitation agricole et industrielle; Thème 5: Importance économique et commerciale des innovations technologiques pour le développement des chaînes de valeur agricoles/agro-alimentaires