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Toumi S.,National School of Hydraulic Engineering, Blida | Meddi M.,LGEE | Mahe G.,IRD | Mahe G.,Montpellier University | Brou Y.T.,University of Artois
Hydrological Sciences Journal

In this study, remote sensing and geographic information systems (GIS) are implemented in order to map and assess water erosion using the Universal Soil Loss Equation (USLE) in the Wadi Mina watershed in Algeria. The study area is characterized by great irregularity in rainfall which is mainly generated during storm events. The region is also known for its steep slopes, marly lithology and very sparse vegetation cover, making it more exposed and vulnerable to erosion. The USLE model can be described as the combination of six factors that feature the specific characteristics of the watershed. Data from multi-temporal remote sensing analysis and GIS are used to individually assess and map each factor. Integration of thematic maps for the USLE factors in the GIS is used to identify the impact of each factor on soil loss, as well as to rank the relative importance of the erosion zones, and further to quantify soil loss in the investigated region. © 2013 © IAHS Press. Source

Abbes A.S.B.,University of Science and Technology of Oran | Meddi M.,National School of Hydraulic Engineering, Blida
International Journal of Hydrology Science and Technology

The watershed of the studied region, part of the large basin of Macta situated in the north-west of Algeria, is submitted to flash floods and is particularly dangerous. Facing to the recurring of those catastrophic events, the understanding of hydrologic process constitutes a strategic axis of prevention against floods. Functioning indicators of the basin have been searched for by modelling of the flow on different floods observed at level of the stations established along Mekkera Wadi. Among hydrologic models, the Muskingum model has been chosen for floods propagation study and estimations of flows, and the QdF model is used to evaluate the extreme quintiles and build the hydrographs of different return periods. The floods episodes observed at level of stations of Sidi Ali Benyoub and of Sidi Bel Abbès are characterised by importance of damages caused. The town of Sidi Bel Abbès built in the major bed of Mekkera and so the communes situated in the plains are the most exposed to these sudden floods. Copyright © 2016 Inderscience Enterprises Ltd. Source

Ladoux P.,National School of Hydraulic Engineering, Blida | Raimondo G.,Airbus | Caron H.,French National Railways Company SNCF | Marino P.,The Second University of Naples
IEEE Transactions on Power Electronics

This paper presents a new technique in voltage balancing for single-phase railway substations. Using the concept of chopper-controlled impedance, the authors study the feasibility of an active Steinmetz circuit based on ac choppers. The low power losses in semiconductor devices make the proposed topology an interesting alternative to classical solutions such as those based on voltage source inverters. Design criteria are presented using information obtained from measurements carried out on a substation of the French National Railways. Finally, the study is validated by means of simulations and experimental results carried out on a 1.5 kVA prototype. © 2013 IEEE. Source

Yahia M.,University of Limoges | Tao J.W.,National School of Hydraulic Engineering, Blida | Sakli H.,National Engineering School of Tunis
Progress In Electromagnetics Research C

We hybridize vector Finite Element Method (FEM) and a Modified Multimodal Variational Formulation (MMVF) to the accurate and fast design of complex isotropic rectangular filters. The MMVF is applied to the full-wave description in the rectangular waveguides while the FEM characterizes waves in the arbitrarily shaped discontinuities. The proposed hybrid method is applied to the full-wave analysis of circuits with great practical interest (i.e., cross-shaped iris and multimode filters), thus improving CPU time and memory storage against several full-wave FEM based Computer Aided Design (CAD) tools (i.e., HFSS High Frequency Structural Simulator). The performances of the proposed hybrid method are validated with experimental results and HFSS simulations. Source

Meddi M.,National School of Hydraulic Engineering, Blida
Journal of Urban and Environmental Engineering

Soil erosion by rain and surface runoff is an important problem in the Mediterranean countries. The study of the relationship between erosion and sediment transport with hydrological and climatic factors have been conducted in many countries around the world. The aim of this work is to show rainfall impact on the variability of spatial and temporal concentration in twelve drainage basins in the west of Algeria. We will also seek to find a representative parameter of rainfall erosive potential on a Time and spatial scale. When studying sediment transport in twelve drainage basins of the Centre and the west of Algeria, we have found that the modified Fournier index Which explains much of the specific degradation compared to the Fournier index. The study of the temporal variability of the annual rainfall series, modified Fournier index and concentration of the precipitation in the year for a series from 1930 to 2007 showed a negative trend of the two variables. The annual rainfall and modified Fournier index have declined by more than 20%. This decline is more significant in inland areas. © 2013 Journal of Urban and Environmental Engineering (JUEE). All rights reserved. Source

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