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Noordally R.,Laboratoire Dinformatique Et Of Mathematiques | Nicolay X.,Laboratoire Dinformatique Et Of Mathematiques | Anelli P.,Laboratoire Dinformatique Et Of Mathematiques | Lorion R.,Laboratoire DEnergetique | Tournoux P.U.,Laboratoire Dinformatique Et Of Mathematiques
Asian Internet Engineering Conference, AINTEC 2016 | Year: 2016

Internet connectivity is not fairly distributed around the world, in particular for islands or isolated areas. An example, the internet connection of Reunion Island is mainly based on links to France located about 10; 000kms away. This situation generated a particular connection which induced high delays and degraded internet service. Typically, the minimal delay between France and Reunion Island is around 180ms. In this paper, we investigate the performance of the Internet connection by analyzing delay and path properties from and to Reunion Island mapped to continent IPv4 spread. With two experiments, based on 27 local probes and 7; 860; 000 traces, we propose a correlation analyzing between delay and path properties. One particular finding is that the delay is more dependent of the chosen path as the geographical distance, compared to models in literature. © 2016 ACM.

Alloune R.,Renewable Energy Development Center Algeria | Alloune R.,Laboratoire dEnergetique | Alloune R.,Ecole des Mines de Nantes | Balistrou M.,Laboratoire dEnergetique | And 3 more authors.
Journal of the Energy Institute | Year: 2017

The aims of this study is to investigate the performance, combustion and exhaust emissions of a single-cylinder, air cooled, direct injection (DI), compression ignition engine using biodiesel from non-edible feedstock. In this work, biodiesel (B100) used to lead this investigation is Citrullus colocynthis L. methyl ester (CCME) and its blends B30 with diesel fuel. The biodiesel is produced via alkaline-catalyzed transesterification process using methanol (6:1 M ratio), 1% of sodium hydroxide at the reaction temperature of 60 °C for 1 h. The important physical and chemical properties of CCME are close to those of diesel fuel. Fuels (diesel fuel, B100 and B30) were tested on a DI diesel engine at 1500 rpm for various power outputs. The results indicated that B100 and B30 exhibit the same combustion characteristics compared to diesel fuel. However, B100 and B30 display earlier start of combustion. At lower engine loads, the peaks of cylinder pressure and heat release rate (HRR) were higher for B30 than B100 and diesel fuel during premixed combustion period. At higher engine loads the peaks of cylinder pressure was higher for B100 than B30 and diesel fuel, but the HRR during diffusion combustion is more considerable than diesel fuel. The brake specific fuel consumption (BSFC) was higher for B100 than diesel fuel at all engine loads while B30 exhibited comparable trends. The thermal efficiency is slightly higher for B100 than B30 and diesel fuel at low loads and increase for B30 at full loads.B30 and B100 provided a higher reduction of hydrocarbons emissions up to 50% for B100. Nitrogen oxides and particulate matter emissions were also reduced. © 2017 Energy Institute.

Lounici M.S.,Ecole des Mines de Nantes | Lounici M.S.,Laboratoire dEnergetique | Loubar K.,Ecole des Mines de Nantes | Tarabet L.,Laboratoire des systemes thermiques | And 3 more authors.
Energy | Year: 2014

The use of natural gas in compression ignition engines as supplement to liquid diesel in a dual fuel combustion mode is a promising technique. In this study, the effect of DF (dual fuel) operating mode on combustion characteristics, engine performances and pollutants emissions of an existing diesel engine using natural gas as primary fuel and neat diesel as pilot fuel, has been examined. At moderate and relatively high loads, the results show very interesting behavior of dual fuel operating mode in comparison to conventional diesel, both for engine performance and emissions. It showed a simultaneous reduction of soot and NOx species over a large engine operating area. Moreover, it showed the possibility to obtain lower BSFC (brake specific fuel consumption) than conventional diesel engine. However, this mode presents some deficits at low loads, especially concerning unburned hydrocarbons and carbon monoxide emissions. Understanding those deficiencies is a key of such engines improvement. Some suggestions for new measures towards DF mode improvement are deduced. © 2013 Elsevier Ltd.

Babbah S.,Laboratoire dEnergetique | Maestre I.R.,University of Cádiz | Draoui A.,Laboratoire dEnergetique | Cubillas P.,University of Cádiz | Gallero F.J.G.,University of Cádiz
International Journal of Energy, Environment and Economics | Year: 2012

The majority of the buildings existing in the North of Morocco have a badly construction adapted to the climate of the area. This has, as a result, a strong energy consumption both in winter and in summer which is not desirable economically, and it also has a negative impact on the environment. The aim, within the framework of this work, is to obtain a thermal comfort level with an energy consumption reduced by analyzing the influences of constructive quality and the orientation of the building for its energy needs. For that, we carried out a description and analyzed various types of buildings of the area in the North of Morocco. This enabled us to release certain types of residences representative from the point of view of the construction materials used and typology. © 2011 Nova Science Publishers, Inc.

Dansoko M.,Laboratoire dEnergetique | Nkwawo H.,University of Paris 13 | Diourte B.,Laboratoire dEnergetique | Floret F.,University of Paris 13 | And 2 more authors.
International Journal of Electrical Power and Energy Systems | Year: 2014

This article proposes a new decentralized sliding mode control design for two synchronous generators driven by marine turbines. Decentralized Sliding Mode Multimachine Control (DSMMC) is applied to a third-order model of the wound rotor synchronous generator in multimachine configuration. Our goal consists in regulating frequency and voltage of synchronous generators in order to ensure their direct interconnection. In addition, the control strategy named Maximum Power Point Tracking (MPPT) is used to maximize the energy production. Simulations in Matlab environment are realized for a semidiurnal type tide (tide of period 12 h 25 min) using data of Raz de Sein (Britany, France). Simulations results are presented in order to highlight robustness properties under mechanical and electrical perturbations. Finally, our control method is compared to Decentralized NonLinear Control (DNLC) and conventional AVR-PSS. © 2014 Elsevier B.V. All rights reserved.

Dansoko M.,Laboratoire dEnergetique | Nkwawo H.,University of Paris 13 | Diourte B.,Laboratoire dEnergetique | Floret F.,University of Paris 13 | And 2 more authors.
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013

This article presents the decentralized sliding mode control design for two marine turbines connected to Grid. MPPT strategy control (Maximum Power Point Tracking) is used to maximize the energy production. Simulations in Matlab environment are made over one tide period of semidiurnal type and under some perturbations using data of Raz de Sein (Britany, France). In the first part of the simulation, the obtained results show that the energy production system can be directly connected to grid. In the second part of simulations, a comparative result using the proposed method and conventional AVR-PSS is discussed. © IFAC.

Grondin D.,CNRS Physical Eletrochemistry Materials and Interfaces Lab | Grondin D.,Laboratoire dEnergetique | Deseure J.,CNRS Physical Eletrochemistry Materials and Interfaces Lab | Ozil P.,CNRS Physical Eletrochemistry Materials and Interfaces Lab | And 3 more authors.
Journal of Power Sources | Year: 2011

Classical solid oxide fuel cell anode (Ni-cermet) could be employed as solid oxide electrolysis cell cathode. Ni-cermet has been synthesized and tested as solid oxide electrolyzer cathode using three-electrode techniques between 700 °C and 900 °C. yttria stabilized zirconia was used as the electrolyte and Pt as the counter electrode. Polarization curves and impedance spectra have been analyzed for two gas compositions. The presented results demonstrated an influence of Ni-cermet electrode behavior upon gas composition and temperature. The present results highlight a mechanism changing on Ni-cermet electrode upon gas composition. In a second part, a one-dimensional steady state model is developed to predict the cathodic behavior of Ni-cermet. This model takes into account mass and charge conservation, transport of species and reaction kinetics. It considers the porous electrode to be a homogeneous medium characterized. The influence of varying chemical and electrochemical steps kinetic on the shape of polarization curves is discussed. At high overpotential values the model with two rate-limiting steps has been validated using numerical optimization method. © 2011 Elsevier B.V.

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