Influence of the key parameters on the dynamic behavior of the hydrogen absorption by LaNi5

The optimal design of hydride tanks is a major technological issue for the rapid development of this technology. In this paper, a two-dimensional model of a closed metal–hydrogen reactor is presented. The temperature and the pressure temporal evolutions within the reactor as a function of time are reported. In order to determine the parameters to optimize a fast kinetic and optimal heat exchange, the impact of the supply pressure, the porosity and the dynamic viscosity have been studied. The results show that the effect of these parameters are key-factors for an optimized tank design.     

Measuring Geospatial Properties: Relating Online Content Browsing Behaviors to Users’ Points of Interest

With the growth of the Mobile Internet, people have become active in both the online and offline worlds. Investigating the relationships between users’ online and offline behaviors is critical for personalization and content caching, as well as improving urban planning. Although some studies have measured the spatial properties of online social relationships, there have been few in-depth investigations of the relationships between users’ online content browsing behaviors and their real-life locations. This paper provides the first insight into the geospatial properties of online content browsing behaviors from the perspectives of both geographical regions and individual users. We first analyze the online browsing patterns across geographical regions. Then, a multilayer-network-based model is presented to discover how inter-user distances affect the distributions of users with similar online browsing interests. Drawing upon results from a comprehensive study of users of three popular online content services in a metropolitan city in China, we achieve a broad understanding of the general and specific geospatial properties of users’ various preferences. Specifically, users with similar online browsing interests exhibit, to a large extent, strong geographic correlations, and different services exhibit distinct geospatial properties in terms of their usage patterns. The results of this work can potentially be exploited to improve a vast number of applications.     

Performances for a synchronous machine with optimised efficiency while wide speed domain is attempted

A combined control technique is proposed to improve the efficiency of an in-wheel motor with outer rotor for traction system. The double excited motor has permanent magnets and field winding as excitation sources. The 'combined control strategy' employed in the extended speed operation is based on an alternate field-weakening technique by negative d-axis current injection and by adequately feeding the auxiliary field winding, respectively. The alternate technique proposed is detailed and the computed results are obtained using 2D finite-element method analysis, and the MATLAB/Simulink package stand by to validate it. The tests will prove the expected speed gain and the validity of the machine's topology.     

SimRDH: A Modeling and Simulation Environment With Component Hybrid Dynamic Nets, Elevator Application

Component hybrid dynamic nets (CHDNs) are a graphic model for hybrid dynamic systems, which allow every component of the hybrid system to be individually represented. On the basis of this methodology, a software tool dedicated to electrical engineering simulations has been developed. Thus, the aim of this paper is to present a brief review of the model structure and to describe the developed software called SimRDH. In order to show the applications of this software tool, a hydraulic system, a mechanical system, and finally, an elevator system powered by supercapacitors have been studied.     

Exploring the power of social hub services

World Wide Web - Given the diverse focuses of emerging online social networks (OSNs), it is common that a user has signed up on multiple OSNs. Social hub services, a.k.a., social directory...     

A novel approach for modeling the internal behavior of a PEMFC by using electrical circuits

This paper presents a method for modeling a PEMFC by using electrical circuits. In particular, it focuses on temperature and voltage distribution of fuel cell. The current distribution is calculated by using the Newton-Raphson method in order to estimate the physical parameters (connection resistances) of the model. Several test on a single PEMFC cell have been carried out during this study. In order to validate the model, temperature and voltage sensors have been installed in different segments of a single cell. A distinguishing advantage of the developed model is its ability to detect and localize the faults within the PEMFC cell, as well as simulate different faults in all of the three directions of the PEMFC cell.     

Evaluation of the effect of fennel (Foeniculum vulgare Mill) essential oil addition on the quality parameters and shelf‐life prediction of yoghurt

Yoghurt was prepared by adding three concentrations of fennel essential oil (FEO) (2.5, 5 and 7.5 µL) in 100 mL of pasteurised milk. Fennel essential oil did not affect the viability of yoghurt starters during fermentation. Based on sensory analysis, only the 5‐µL FEO concentration was incorporated in order to investigate the physicochemical and microbiological properties of enriched yoghurt during storage. Results showed that FEO in yoghurt did not significantly affect the quality after acidification (P > 0.05). However, total solid content, syneresis and lightness (L*) differed significantly (P < 0.05). Bacterial counts indicated that the control yoghurt had the highest values. Fortified yoghurt had an increased shelf life of 29 days.     

Vibratory behavior reduction of electrical machines through materials properties evaluation

Most of the electromagnetic devices, especially electrical machines, have the disadvantage to be exposed to high vibrations caused by magnetic forces. The aim of this study is to propose a methodology to optimize the cylindrical stators generally used in electrical machines regarding the vibration phenomena. Techniques for vibration reduction require knowledge of the proper frequencies, which depend on mechanical shapes and dimensions as well as material properties such as mass density, Young's modulus and Poisson's ratio. This paper proposes a new approach which is based on the identification of mass density (lamination stacking factor) and Young's modulus in the goal to minimize the vibratory behavior of electrical machines. In this goal, we have used artificial intelligent and finite element method (FEM) analysis to solve the magneto‐mechanical inverse problem (IP). In the proposed approach, a Multilayer Perceptron Neural Network (MLPNN) is used as a forward model in order to decrease the FEM time consuming. Thus, a Genetic Algorithm (GA) is used to solve the IP in a reasonable time of running. An example study of an induction machine proves that the developed approach may be applied in both design and identification applications. Copyright © 2011 John Wiley & Sons, Ltd.