The Effect Of Catalyst Support On The Decomposition Of Methane To Hydrogen And Carbon.

Decomposition of methane into carbon and hydrogen over Cu/Ni supported catalysts was investigated. The catalytic activities and the lifetimes of the catalysts were studied. Cu/Ni supported on Ti02 showed high activity and long lifetime for the reaction. Transmission electron microscopy (TEM) studies revealed the relationship between the catalyst activity and the formation of the filamentous carbon over the catalyst after methane decomposition

A realistic testing of a shipboard wireless sensor network

International audienceWireless Sensor Networks (WSN) may be a very useful technology for monitoring systems in hostile environments. Few works have treated the use of this technology in the particular metallic shipboard environment. This paper reports on the deployment of a WSN on board a ferry in realistic conditions. The network was tested during sailings and stopovers for several days. The results of our previous papers reporting on the radio wave propagation on board ships are recalled. Network performance and its topology evolution with respect to previous results are presented. In spite of the metallic structure of ferries and the dynamic movement of crew and passengers on board, the results show a significant network reliability and connectivity. The previous conclusions have been also confirmed by the topology evolution of the network and the analysis of RSSI levels of links between sensor nodes

A Realistic Experiment of a Wireless Sensor Network on Board a Vessel

International audienceWireless Sensor Networks (WSN) may be a very useful technology for monitoring systems in hostile environments. Few works have treated the use of this technology in the particular metallic shipboard environment. This paper reports on the deployment of a WSN on board a ferry-type boat during realistic conditions. The network was tested during sailings and stopovers for several days. The results of our previous papers reporting on the radio wave propagation on board ships are recalled. The network performance and a comparison of its evolution with respect to previous results are presented. In spite of the metallic structure of ferries and the dynamic movement of crew and passengers on board, the results have shown a very good network reliability and connectivity. The previous conclusions have been also confirmed by the topology evolution of the network and the analysis of RSSI levels of links between sensor nodes

A Realistic Experiment of a Wireless Sensor Network on Board a Vessel

International audienceWireless Sensor Networks (WSN) may be a very useful technology for monitoring systems in hostile environments. Few works have treated the use of this technology in the particular metallic shipboard environment. This paper reports on the deployment of a WSN on board a ferry-type boat during realistic conditions. The network was tested during sailings and stopovers for several days. The results of our previous papers reporting on the radio wave propagation on board ships are recalled. The network performance and a comparison of its evolution with respect to previous results are presented. In spite of the metallic structure of ferries and the dynamic movement of crew and passengers on board, the results have shown a very good network reliability and connectivity. The previous conclusions have been also confirmed by the topology evolution of the network and the analysis of RSSI levels of links between sensor nodes

REST API auto generation: a model-based approach

t. Most of software products, especially mobile applications (apps) rely on a back-end web services to communicate with a shared data repository. Statistics have demonstrated exponential demand on web services, mainly REST, due to the continuous adoption of IoT (Internet of Things) and Cloud Computing. However, the development of back-end REST web services is not a trivial task, and can be intimidating even for seasoned developers. Despite the fact that there are several studies that focus on automatic generation of REST APIs, we argue that those approaches violate the rules of code flexibility and are not appropriate for novice developers. In this study, we present an approach and a framework, named RAAG (REST Api Auto-Generation), that aims to improve productivity by simplifying the development of REST web services. Our RAAG framework abstracts layers, where code generation has been avoided due its limitations. A preliminary evaluation shows that RAAG can significantly improves development productivity and is easy to operate even by novice developers

DYNAMIC SOIL-STRUCTURE INTERACTION ANALYSIS: DETECTING THE RELIABILITY OF MODELLING THE PILES AS A PLATE ELEMENT FOR A MULTISTORY BUILDING RESTING ON DEEP FOUNDATION

The assessment of seismic responses of buildings in dynamic-soil-pile-structure interaction problems has been one of the main interests among researchers in recent decades. Simulating such problems is usually done by two-dimensional models to overcome the difficulties encountered in 3D models. Commonly, piles were represented by plate elements of infinite length, disregarding the soil flowing between piles. Recently, Plaxis – a finite element software- implemented a new feature known as “the embedded pile row” that allows the definition of piles\u27 out of plane spacing in a 2D model. Many researchers proved its validity in accurately simulating the real 3D pile’s behavior. The objective of this paper is to detect the reliability of modeling the piles as plate elements, by comparing the performance of the structural-pile system with the plate feature to that with the embedded pile row feature. A series of 2D finite element models are generated while varying the soil type, the earthquake frequency content, and the out-of-plane piles\u27 spacing. This paper demonstrated that the building response with piles modeled as plate elements is just adequate when the surrounding soil is dense. Yet, regarding the pile response, the plate feature is unable to capture the real behavior for all soil types

Performance Analysis of a Hierarchical Shipboard Wireless Sensor Network

International audienceWireless Sensor Networks (WSN) have recently gained a great attention in several applications such as environmental monitoring and target tracking. Applying this technology to shipboard monitoring systems may be a cost-effective solution to reduce the cost of wires installation and maintenance. However, wireless communications on board ships may be severely obstructed by the metallic structure of bulkheads. In this paper, we analyze the efficiency of a shipboard WSN by measurement and simulation. A measurement campaign is conducted to study the radio wave propagation and to verify the feasibility of a WSN on board a ship. Based on the measurement results, a hierarchical group-based topology for a large-scale shipboard WSN is proposed. A realistic simulation model of the ship, taking into account the environment particularities, is then performed using OPNET network simulator. Performance of the WSN architecture is evaluated using the ZigBee model. Measurement results show the feasibility of WSN technology on board ships, while simulation results show significant performance of proposed architecture in terms of end-to-end delay and packet delivery ratio

Wireless Sensor Network on Board Vessels

International audienceWireless Sensor Networks (WSNs) have been used recently in different applications such as environmental monitoring and target tracking. Few papers have investigated the viability of this technology on board ships. We study in this paper the possibility of replacing the wired shipboard monitoring system by a WSN. This environment has a specific metallic structure which makes the wireless communication more difficult than in other classical indoor and outdoor environments. Two types of experiments have been carried out on board a ferry-type boat during sailings and stopovers. The first experiment consists of point-to-point measurements using ZigBee-based equipments and the second one consists of deploying and testing a WSN on board the ferry. These tests have been conducted during realistic conditions on board the ferry, which give a high level of reliability to results with respect to the earlier experiments on board ships moored to the harbor. In spite of the harsh metallic structure and the dynamic environments on board the ferry, the obtained results have shown that the wireless solution may be a cost-effective alternative of the huge amount of cables used actually to connect sensors to central control units

Étude de la propagation des ondes électromagnétiques pour le déploiement des réseaux sans fil à bord d'un bateau

International audienceAfin de déployer des réseaux de communications sans fil (réseau local sans fil, réseau de capteurs, téléphone sans fil) à bord des navires, une étude de la propagation des ondes électromagnétiques (EM) est nécessaire dans cet environnement particulier. En effet, les communications sans fil à l'intérieur d'un bateau peuvent être sévèrement limitées par la structure métallique des ponts, des cloisons et des portes étanches. Cet article présente une étude expérimentale de la propagation des ondes EM à bord des navires. Ce travail fait partie du projet SAPHIR financé par la région Bretagne. Des mesures en porteuse pure, visant à déterminer la couverture radioélectrique pour des environnements typiques, ont été réalisées à bord d'un ferry. Ensuite, d'autres mesures, consistant en une caractérisation doublement directionnelle du canal de propagation en utilisant un sondeur MIMO (Multiple Input Multiple Output), ont été réalisées. Les mesures MIMO visent à déterminer les principales directions de propagation des ondes EM dans des scénarios typiques, tels que la communication entre des pièces adjacentes, les ponts adjacents, ou entre les cabines des passagers et les couloirs

Mechanism And Rate Limiting Step For The Catalytic Decomposition Of Methane To Hydrogen And Carbon Nanotube.

The main focus of this paper is to report a mechanism, a rate-limiting step, and a rate law consistent with experimental observation for the decomposition of methane to hydrogen and carbon nanotube over Ni/Mn based catalyst