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The Dynamic Penetration Test (DPT) is one of the simplest and least expensive in-situ tests, used in geotechnical projects. However, in the literature, there is no available practical method for co...

To enhance the robustness and dynamic performance of a self-excited induction generator (SEIG) used in a stand-alone wind energy system (WES), a virtual flux oriented control (VFOC) based on nonlinear super-twisting sliding mode control (STSMC) is adopted. STSMC is used to replace the conventional proportional-integral-Fuzzy Logic Controller (PI-FLC) of the inner current control loops. The combination of the proposed control strategy with space vector modulation (SVM) applied to a PWM rectifier brings many advantages such as reduction in harmonics, and precise and rapid tracking of the references. The performance of the proposed control technique (STSMC-VFOC-SVM) is verified through simulations and compared with the traditional technique (PI-FLC-VFOC-SVM). It shows that the proposed method improves the dynamics of the system with reduced current harmonics. In addition, the use of a virtual flux estimator instead of a phase-locked loop (PLL) eliminates the line voltage sensors and thus increases the reliability of the system.

The emerging behavior in complex systems is more complicated than the sum of the behaviors of their constituent parts. This behavior involves the propagation of faults between the parts and require...

Background: Ultrafiltration membrane processes have become an established technology in the treatment and reuse of secondary effluents. Nevertheless, membrane fouling arises as a major obstacle in the efficient operation of these systems. Aim/Objective: This study evaluates the factors affecting pretreatment conditions for combination ultrafiltration membrane processes for reuse of secondary effluent from the sewage treatment plant. The objective of this work is to study the precoagulation effect on the removal of organic matter from secondary effluent from the wastewater treatment plant Reghaïa (Algiers) and for fouling of the membranes ultrafiltration. Methods: A comparison was made between two coagulant FeCl3 and Fe2(SO4)3 using two processing systems, Coagulation (with sedimentation) / Ultrafiltration and Coagulation (without sedimentation) / Ultrafiltration. The optimum conditions for coagulation were determined by the analysis UV254 and turbidity. Result: The results showed that there's a better reduction of the decrease of permeate flux (Jv) in the coagulation system (without sedimentation)/Ultrafiltration for both coagulants because of trapping of organic molecules responsible for fouling of the membrane inside the porous flocs formed in the coagulation.

This paper deals with the robust power control of a grid-connected brushless doubly-fed induction generator (BDFIG) driven by the variable speed wind turbine. With the using of a super twisting algorithm which is a high-order sliding mode controller (HOSMC). This approach guarantees both the dynamic performance and the same robustness as traditional first order (SMC) algorithm and reduces the chattering phenomenon, which is the biggest disadvantage in the implementation of this technique. The developed algorithm relies on the decoupling control by implementing the strategy of oriented grid flux vector control. In order to enhance the desired performances, an attempt is made by controlling the generated stator active and reactive powers in a linear and decoupled manner to ensure the global asymptotical stability, HOSMC approach is implemented. Therefore, an optimal operation of the BDFIG in sub-synchronous operation is used in addition to the stator power flows where the stator power factor is kept in a unity. The suggested method is examined with the Matlab/Simulink software. The performances and the feasibility of the designed control are illustrated by simulation results.

In our article we realized a solar distiller with four floors. The distiller tested is poly-energy, it can operate by three different energy sources: electrical resistance (power grid or photovoltaic panel), photo thermal solar collector or vegetable and animal waste. A cylindro-parabolic solar collector used to collect the heat necessary for the distillation is coupled to the four-stage still. The tested trays of the still have two different forms: “V” and “Λ”. The water desalination is done by many technologies such as the multi-stage still which is tested experimentally in this work under the weather conditions of the city of Batna, Algeria (35° 45′ North, 6° 19′ East). “V” shaped trays are the most efficient at producing distilled water because it is cheaper and more cost effective than the “Λ” floor that requires two collectors. The electricity consumption of the distiller depends on the amount of heat lost by the distiller, and the cost of electricity consumed by the distiller depends on the type of trays. The water produced by the trays of the form Λcosts more than the trays of form V.

Objectives: To combine several biometric methods used for face and iris simultaneous recognition of an individual in order to enhance the performance. Methods/Analysis: For every methodology, four approaches are used for features extraction: discrete wavelet transform, singular value decomposition, discrete cosine transform and principal component analysis. Then, matching is employed by different distance measurements: City block, Euclidean, Seuclidien, Cosine, Chebychevand Correlation. Findings: The most widely used normalization method such as min-max and a new method using geometric mean is presented. The data fusion is performed at the score level with two methods: simple sum and weighted sum. The obtained comparison results show that PCA (face) and PCA (iris) fusion scenario associated with simple sum rule and the proposed new normalization method (geometric mean) have given the best recognition rate. Application/Improvements: This new normalization method helps considerably to enhance other methods in a multimodal biometric recognition system. Keywords: Distances, Face, Fusion, Geometric Mean, Iris, Multimodal Biometrics, Recognition Rate

The present paper deals with the experimentation of a hydrogenated Palm Kernel vegetable fat as a novel bio-based Phase Change Material (PCM). This bio-based PCM with 26.53 °C of melting temperature and 74.35 J/g of the latent heat capacity of fusion was recovered from abundant and renewable underused feedstocks. The purpose is to trap this PCM without leakages into the internal microstructure of a prepared supporting material (matrix) first; and then to propose the resulting composite-PCM for a practical application of passive TES in building envelopes. This matrix was prepared from available, low-cost and eco-friendly components. However, natural clay and cellulose fibers were principally used in the preparation of the PCMs’ supporting material. 53 wt percent (wt%) of the bio-based PCM were successfully incorporated in this matrix after the direct immersion method thanks to the capillary and surface tension forces . Differential Scanning Calorimetry (DSC) results showed that the Thermal energy storage characteristics of the obtained composite-PCM are suitable for building applications. This melts at 27.33 °C with 40.27 J/g of latent heat capacity of fusion. Thermo Gravimetric Analysis (TGA) revealed that the prepared composite-PCM maintains a good thermal reliability in its working temperature range. The Hot-Disk results proved that the addition of graphite improved its thermal conductivity . Fourier Transformed Infrared Spectroscopy (FT-IR) confirmed the chemical stability of the prepared material. Finally, Scanning Electron Microcopy (SEM) showed that the bio-based PCM is successfully retained by the microstructure of the prepared matrix after the impregnation process.

The unsteady flow characteristics and responses of an NACA 0012 airfoil fitted with a bio-inspired morphing trailing edge flap (TEF) at near-stall angles of attack (AoA) undergoing downward deflections are investigated at a Reynolds number of 0.62 × 106 near stall. An unsteady geometric parametrization and a dynamic meshing scheme are used to drive the morphing motion. The objective is to determine the susceptibility of near-stall flow to a morphing actuation and the viability of rapid downward flap deflection as a control mechanism, including its effect on transient forces and flow field unsteadiness. The dynamic flow responses to downward deflections are studied for a range of morphing frequencies (at a fixed large amplitude), using a high-fidelity, hybrid RANS-LES model. The time histories of the lift and drag coefficient responses exhibit a proportional relationship between the morphing frequency and the slope of response at which these quantities evolve. Interestingly, an overshoot in the drag coefficient is captured, even in quasi-static conditions, however this is not seen in the lift coefficient. Qualitative analysis confirms that an airfoil in near stall conditions is receptive to morphing TEF deflections, and that some similarities triggering the stall exist between downward morphing TEFs and rapid ramp-up type pitching motions.

This work explores the aerodynamic and aeroacoustic responses of an airfoil fitted with a harmonically morphing Trailing Edge Flap (TEF). An unsteady parametrization method adapted for harmonic morphing is introduced, and then coupled with dynamic meshing to drive the morphing process. The turbulence characteristics are calculated using the hybrid Stress Blended Eddy Simulation (SBES) RANS-LES model. The far-field tonal noise is predicted using the Ffowcs-Williams and Hawkings (FW-H) acoustic analogy method with corrections to account for spanwise effects using a correlation length of half the airfoil chord. At various morphing frequencies and amplitudes, the 2D aeroacoustic tonal noise spectra are obtained for a NACA 0012 airfoil at a low angle of attack (AoA = 4°), a Reynolds number of 0.62 × 106, and a Mach number of 0.115, respectively, and the dominant tonal frequencies are predicted correctly. The aerodynamic coefficients of the un-morphed configuration show good agreement with published experimental and 3D LES data. For the harmonically morphing TEF case, results show that it is possible to achieve up to a 3% increase in aerodynamic efficiency (L/D). Furthermore, the morphing slightly shifts the predominant tonal peak to higher frequencies, possibly due to the morphing TEF causing a breakup of large-scale shed vortices into smaller, higher frequency turbulent eddies. It appears that larger morphing amplitudes induce higher sound pressure levels (SPLs), and that all the morphing cases induce the shift in the main tonal peak to a higher frequency, with a maximum 1.5 dB reduction in predicted SPL. The proposed dynamic meshing approach incorporating an SBES model provides a reasonable estimation of the NACA 0012 far-field tonal noise at an affordable computational cost. Thus, it can be used as an efficient numerical tool to predict the emitted far-field tonal noise from a morphing wing at the design stage.

This study is aimed at developing a simple and low-cost method to fabricate ZnO-loaded porous activated carbon (AC-ZnO) prepared from the Algerian olive-waste cakes and utilize it as a photocatalyst for the degradation of Ethyl Violet dye. The synthesized AC-ZnO material was characterized using powder X-ray diffraction, BET surface area measurements, Raman microscopy, thermogravimetric analysis, UV-visible diffuse reflectance spectroscopy, and zeta potential measurements. The degradation efficiency was evaluated with Ethyl Violet (EV) dye in aqueous solution under UV irradiation supplied by a Xenon arc lamp through a Pyrex glass filter (cutoff 280 nm), and the degraded products were identified by using electrospray ionization mass spectroscopy. Additional experiments were carried out under N2 flow and with isopropyl alcohol to examine the role of superoxide and hydroxyl radicals, respectively. The amount of ●OH radical formed on irradiated AC-ZnO was tested with terephthalic acid which can act as a chemical trap for the ●OH radicals. The results from this study indicate that the AC-ZnO is a potential catalyst for the pollutant removal and the ●OH radicals are the key species for the degradation of EV. Further, this study opens up an opportunity to produce cheaper activated carbon support from olive wastes for environmental remediation applications.

This paper presents a novel direct rotor flux oriented control with online estimation of magnetizing current and magnetizing inductance applied to self-excited dual star induction generator equipping a wind turbine in remote sites. The induction generator is connected to nonlinear load through two PWM rectifiers. The fuzzy logic controller is used to ensure the DC bus voltage a constant value when changes in speed and load conditions. In this study, a performance comparison between the conventional approach and the novel approach is made. The proposed control strategy is validated by simulation in Matlab/Simulink.

In Algeria, lighthouses are an essential element of the maritime landscape and constitute a substantial part of the local historical and cultural heritage, marked by a great variety of styles, architecture, geometrical forms, and materials. The study presented falls into the general context of pre- and post-seismic conservation of Algerian lighthouses, since all these stone masonry buildings are situated in areas characterized by a medium&ndash, high seismic hazard. In the paper, a relevant example has been analyzed: the Bengut Lighthouse, which has been classified as &ldquo, National Heritage&rdquo, by the Algerian Ministry of Culture and has been severely damaged by the Boumerd&egrave, s that occurred on 21 May 2003. After an overview of historical lighthouses in Algeria and their morpho-typological classification, the case study of the lighthouse at Cap Bengut is presented, showing the results of a detailed survey of the geometric and constructive features and of the actual cracking and damage pattern. First, based on the critical analysis of this knowledge framework, a preliminary qualitative evaluation of the seismic vulnerability has been made, analyzing and classifying the set of local and global failure modes coherently with the observed structural pathologies and damages. Then, numerical modeling has been implemented in TreMuri computer code, performing a set of pushover analyses. This allowed the investigation of the criticalities in the response of the building to seismic actions, characterization of the dynamic behavior, and comparison with the actual observed damages, which are discussed, providing an interpretation of the global and local failure modes. Based on the results of the visual assessment and numerical analysis, guidelines for the retrofitting intervention have been proposed, by considering, on the one hand, the objective of effectively mitigating the elements of vulnerability pointed out by the results and, on the other, the main principles of conservation and restoration. The presented study and its results, in perspective, are intended to provide a basis for developing risk and vulnerability analysis of typological classes of historical lighthouses at a large scale.

The present paper presents a realization of a poly-energy four-stage still, which can operate with three different sources of: electrical resistance (photovoltaic panel), photo-thermal solar collector and vegetable or animal waste. In this work, the effect of the position and the number of trays on the water productivity of a multi-effect still has been experimentally investigated for the first time. A plate was used, then placed in different heights, and then two and three and finally four trays were used. It is concluded that the effect of the tray position has a great influence on the production of distilled water in contrast to the number of trays, and when increasing the number of trays, the production of the distilled water is increased. The maximum production obtained from distilled water is 1 l/h.m². The use of a solar panel for the production of distilled water is unnecessary in oil-producing countries where energy is subsidized. These devices or their components are generally imported and their cost is very expensive. The damping time of these devices is very long.

Purpose The purpose of this paper is to use dynamic meshing to perform CFD analyses of a NACA 0012 airfoil fitted with a morphing trailing edge (TE) flap when it undergoes static and time-dependent morphing. The steady CFD predictions of the original and morphing airfoils are validated against published data. The study also investigates an airfoil with a hinged TE flap for aerodynamic performance comparison. The study further extends to an unsteady CFD analysis of a dynamically morphing TE flap for proof-of-concept and also to realise its potential for future applications. Design/methodology/approach An existing parametrization method was modified and implemented in a user-defined function (UDF) to perform dynamic meshing which is essential for morphing airfoil unsteady simulations. The results from the deformed mesh were verified to ensure the validity of the adopted mesh deformation method. ANSYS Fluent software was used to perform steady and unsteady analysis and the results were compared with computational predictions. Findings Steady computational results are in good agreement with those from OpenFOAM for a non-morphing airfoil and for a morphed airfoil with a maximum TE deflection equal to 5 per cent of the chord. The results obtained by ANSYS Fluent show that an average of 6.5 per cent increase in lift-to-drag ratio is achieved, compared with a hinged flap airfoil with the same TE deflection. By using dynamic meshing, unsteady transient simulations reveal that the local flow field is influenced by the morphing motion. Originality/value An airfoil parametrisation method was modified to introduce time-dependent morphing and used to drive dynamic meshing through an in-house-developed UDF. The morphed airfoil’s superior aerodynamic performance was demonstrated in comparison with traditional hinged TE flap. A methodology was developed to perform unsteady transient analysis of a morphing airfoil at high angles of attack beyond stall and to compare with published data. Unsteady predictions have shown signs of rich flow features, paving the way for further research into the effects of a dynamic flap on the flow physics.

IF=0.918; International audience; The paper is dedicated to the study and the optimization of a magnetohydrodynamic conduction pump. Electromagnetic pumps have several advantages to mechanical pumps, they do not use a moving mechanical part, unlike traditional electric motors, and they transform electromagnetic energy directly into kinetic energy. A fluid is set in motion in a magnetic field by an electric field supplying an electric current to the terminals of electrodes immersed in the fluid. The optimization procedure based on the particle swarm method uses a fitness function as the minimum of the mass. The electromagnetic model is carried out by the finite volume method and the steady fluid flow by COMSOL software. The optimized results of the performance characteristics of the electromagnetic pump are obtained.

The (α‐FeOOH) Goethite composite is a stable and an efficient catalyst in aqueous suspension under irradiation at 365 nm and by solar light. The photocatalytic activities of this composite were evaluated using Phenol Red (PR) dye (phenolsulfonphthalein class). In the dark, controlling factors, such as the pH and the adsorption of PR on Goethite surface were evaluated (before starting the photochemical experiments). It was found that the system PR‐Goethite present a small decrease in the main band of the dye (435 nm) which was explained by the low rate of adsorption of this dye on the Goethite. Also, we note that 40% of PR decolourisation was obtained after 200 min by the system PR‐Goethite‐hydrogen peroxide (H₂O₂) in dark due to the formation of •OH by thermal decomposition of H₂O₂ on the surface of Goethite. The effects of various experimental parameters, such as initial dye concentration, pH, photocatalyst amount, tert‐Butyl alcohol effect and H₂O₂ addition were investigated in the study of photodegradation of the dye. The results showed that the photodegradation of PR under UV‐A (365 nm) irradiation could be enhanced greatly in the presence of H₂O₂. Natural radiation tests (under sunlight) showed that degradation was faster comparing with that obtained using the artificial one at 365 nm. Studies of the mineralization using total organic carbon method under naturel light certify that this method, compatible with the environment, may be considered in the treatment of wastewater and generally in the process of removal of this kind of pollutant.

This paper deals with the seismic response evaluation of the Totem tower of Diar Es Saada, which is one of the taller unreinforced masonry (URM) building in Algeria with twenty floors and 62 m in height. The tower located in Algiers, a town exposed to important earthquakes, has survived so far without major damage or alteration. This high-rise building was designed by the French architect Fernand Pouillon in 1953 without considering regulations for earthquake-resistant construction. It was built in only fifty days by adopting an original structural system and an innovative construction processes developed by this architect: URM stone and brick load-bearing walls with reinforced concrete floors. The study carried out consists of a multidisciplinary approach. First, a detailed diagnosis was performed on site to assess the state of conservation of the building. Then, the seismic behaviour was modelled and analyzed by using both linear dynamic and non-linear static analysis in SAP2000 and TreMuri software. With regard to the current Algerian seismic design regulation, the results obtained in terms of time period, frequency, storey drifts and displacements showed that the tower can be considered as an earthquake-resistant building fulfilling the required structural safety conditions. In this respect, the Totem tower of Diar Es Saada deserves to be classified as a national heritage and its satisfactory overall structural behaviour confirms that the architect Pouillon has also excellent skills in engineering construction.

This paper presents the development and design of a methodology based on fuzzy logic to control an indoor mobile robot for a complete navigation in an unknown environment. The methodology incorporates two basic behaviors, namely: reaching the goal and avoiding obstacles. The obstacle avoidance behavior is treated using wall-following scheme based on an Interval Type-2 Fuzzy Inference technique. .This helps in handling data uncertainties to produce a better performance. The mobile robot control mechanism uses some sort of knowledge base arranged in a set of fuzzy-rule-base to implement the wanted behavior that makes the mobile robot follow the boundary of an obstacle or a wall. A constant distance to the obstacle/wall is maintained while the robot tries successfully to get around this difficulty. Once the path is clear, the obstacle avoidance behavior is inhibited and reaching the goal behavior is activated using a secondary fuzzy controller. This methodology was successfully tested on a real mobile robot for different sort of scenarios. In order to provide better insight into the work’s objective, a comparison work with another method, which uses a Partial Swarm Optimization-Fuzzy method, is carried out based on some defined criteria. The experiment shows a better improvement in the results of the proposed method.

The fixed bed reactor was combined with a solar photoreactor and UV lamp reactor. This hybrid photoreactor used a heterogeneous photocatalysis process (TiO 2 /UV) as a tertiary treatment for the degradation of tartrazine dye in water. The solar reactor removed almost all organic compounds from the wastewater. Photocatalysis was optimized using a parametric study to improve the influence of different parameters on the degradation efficiency. Color removals when using solar, UV lamp and hybrid reactors present 99%, 30%, and 99%, respectively. Tartrazine removal kinetics followed a pseudo-first order model. The hybrid solar and UV lamp system combination was a feasibility choice for removing both dyes from wastewater.

The main goal of this paper is to combine several biometric modalities (face and iris of a person) to improve recognition performance. For each modality, for features extraction, two approaches are used: Fast Fourier Transform (FFT) and singular value decomposition (SVD). Then, Classification is employed by Euclidean distance measurement. The most widely used normalization method such as min-max and z-score and a new method prctile (Percentiles of a data set). The fusion is performed at the score level with four methods such as: simple sum, weighted sum, min and max. Databases of 40 people, extracted from Olivetti Research Laboratory face Database (ORL) and the China Institute of Automation iris database (CASIA), are used for learning and testing the proposed system. Test results show that FFT (face) and FFT (iris) fusion scenario associated with min rule and new method (Prctile) gives the largest recognition result of 98.33%.

It is urgent to act currently on the problems of overconsumption of energy as well as the environment and the economy. Energy is a direct mechanical source of many devices of an artificial thermal environment of the modern habitat. To cope with the consequences of the exceed consumption of domestic use, architecture takes part by focusing on the old constructive and functional solutions. The researchers are interested even fascinated by ancient and vernacular architecture; its buildings are a masterpiece of urban planning in matters of environment. Our study has clearly chosen as an example The Mzab valley; a qualitative and retrospective analysis which aims to describe and classify all the solutions and traditional climate strategies developed by the Mzabites to produce a real thermal comfort and a residential heritage to fight against climatic solicitations. We have checked and observed in parallel if these strategies are convergent or divergent with the recommendations and the needs of the specific comfort in our case study and predetermined in this paper by the method of Givoni. This analysis has shown that Mzabite architecture symbolizes an ancient bioclimatic knowledge, Its strategies generate a perfect harmony between climate, habitat and occupant, they formed an inspiring reference and exemplary lessons available of the designers; by re-adapting these ancient solutions and techniques of our ancestors with a suitable manner to contemporary architecture, and contributing to the improvement of comfortable climate.

The aim of this study is to test the ability of photochemical processes (photolysis, Acetone/UV and H2O2/UV at 254 nm) to eliminate the Methyl Green (MG, cationic structure) and Bromocresol Purple (BCP, anionic structure) in aqueous solution in mono and binary systems. The obtained results show that the rate of decolorization by UV photolysis at 254 nm in single system is weak for BCP (25%) and acceptable for MG (66%). In dark conditions, preliminary experiments show no decolorization of the two dyes in the presence of acetone and in the presence of H2O2 for BCP. However, classical oxidation has been observed for MG in H2O2 for concentrations superior to 5 × 10−4 M. In the presence of light, a real improvement in the decolorization rate of both dyes is obtained using H2O2/UV (acting via issued from photolysis of H2O2 at 254 nm) and Acetone/UV (acting via energy transfer from the sensitizer which is Acetone to the dye). In the mixture systems, the Acetone/UV process is more effective than direct UV...

In this paper, a simulation study of the maximum power point tracking (MPPT) for a photovoltaic system using an artificial neural network is presented. Maximum power point tracking (MPPT) plays an important role in photovoltaic systems because it maximizes the power output from a PV solar system for all temperature and irradiation conditions, and therefore maximizes the power efficiency. Since the maximum power point (MPP) varies, based on the PV irradiation and temperature, appropriate algorithms must be utilized to track it in order maintain the optimal operation of the system. The software Matlab/Simulink is used to develop the model of PV solar system MPPT controller. The system simulation is elaborated by combining the models established of solar PV module and a DC/DC Boost converter. The system is studied using various irradiance shading conditions. Simulation results show that the photovoltaic simulation system tracks optimally the maximum power point even under severe disturbances conditions.

International audience

© 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. A numerical study of the NACA 0012 airfoil fitted with a harmonically morphing trailing edge flap (TEF) is performed at an angle of attack of 4o and a Reynolds number Re = 0.62×106The study focuses on high frequency, low amplitude configurations for the morphing flap and their effects on the aerodynamic performance and flow structures in the wake. Dynamic meshing methods implemented in the commercial software Ansys Fluent and driven by an in-house user-defined function (UDF) were used to model the TEF deformation using a modified unsteady parametrization. The Stress Blended Eddy Simulation (SBES) hybrid turbulence model was used for all parametric studies. For a fixed amplitude, a range of morphing frequencies (lower and higher than the natural shedding frequency) was explored. Obtained results show that at certain high frequencies a slight increase in aerodynamic efficiency could be achieved compared with a baseline design. When the morphing frequency was fixed at its shedding value, the range of amplitudes investigated indicated the presence of an optimal morphing amplitude for which up to 3% increased aerodynamic efficiency could be obtained. Some preliminary results for upstroke and downstroke TEF oscillations are briefly presented to illustrate some differences compared with the main morphing strategy adopted in the paper.

International audience; Ultrafiltration (UF) membrane processes have become an established technology in the treatment and reuse of secondary effluents from sewage treatment plants. However, without pretreatment, secondary-treated wastewater effluent shows high fouling potential and hence reduces the performance of UF membrane filtration significantly. This study investigates the potential reuse of alum sludge collected from a water treatment plant as primary coagulant in terms of membrane fouling reduction. The alum sludge was characterized by scanning electron microscopy with energy-dispersive spectroscopy and X-ray diffraction. A comparison was made between a conventional metal-ion coagulant - aluminum sulfate [Al2(SO4)3] - and alum sludge using a jar test and their performances were measured in terms of residual turbidity, UV254 (absorbance at 254 nm), and chemical oxygen demand (COD) removal. UF experiments were performed with CARBOSEP M3 (40 kDa) monotubular ceramic. It was shown that the application of coagulation by alum sludge restricted the fouling of membranes with a lowering of the permeate flux by only 34%. The results showed that alum sludge was effective in removal of organic matter; percent removal of COD and UV254 reached 90% and 60%, respectively, when combining alum sludge with UF. © 2018 American Society of Civil Engineers.

This paper proposes the modeling and control of Wind Energy Conversion Systems (WECS) based on Doubly Fed Induction Generator (DFIG). The fuzzy logic control is used to improve the extracted wind power at given wind velocity; the mechanical power available from a wind turbine is a function of its shafts speed. Then, the rotor side converter (RSC) is controlled in the aim to follow the optimal torque for given maximal wind power. The effectiveness of the proposed control strategy is validated by theoretical analysis and simulation carried out in Matlab/Simulink environment.

The aim of this work is to evaluate the performance of a submerged membrane bioreactor that operated continuously for 200 days and to assess biomass activity and membrane fouling under various operating conditions. Furthermore, a method for the characterisation of biomass activity is developed based on its separation into various fractions. Respirometry and Activated Sludge Models are used as biological process to identify active biomass and species of activated sludge. However, the equations describing the active biomass are developed. The submerged membrane bioreactor system operated at the solids retention times of 40 and 60 days with organic loading rate of 0.5635 kg/COD/m−3/day−1 and chemical oxygen demand/nitrogen ratio of 3.5. Activated sludge is generated in a system fed with soluble and easily biodegradable substrate [ethanol/sodium acetate (1:1)], this synthetic wastewater, containing no hardly biodegradable organic or inorganic particulate matter, has led to the generation of a sludge constituted essentially of two fractions: active biomass and cell debris.

In this paper, an adaptive tracking controller for a piezo-actuated stage is designed considering the LUGRE model. The adaptation algorithm of the parameterized hysteretic function is used to achieve a displacement-tracking objective under the mechanical parameters uncertainties. The Lyapunov theory is used to derive an adaptive law for the system stability. The effectiveness of the proposed controller is validated considering real-time simulation. The validation results of the proposed controller presents good performances and robustness under an external load-disturbance and parameter uncertainties.

In this paper, we propose a vector control of a doubly fed induction generator (DFIG) for variable speed wind power generation. The model is developed based on the dual powered generator for the control of the active and reactive powers. Several studies are carried out to test their operation under different wind conditions. The results have shown good performances of the wind energy converter system operate under wind variations with indirect vector control strategies.

The present study deals with wurtzite ZnS nanoparticles embedded in zeolite Y, synthesized by γ-radiolysis of exchanged zeolite ZnY in the presence of 2-mercaptoethanol (RSH). The nanocomposites were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), UV–Visible absorption, and photoluminescence (PL). Compared to the bulk state, ZnS nanocrystals have blue – shifted UV visible absorption with an excitonic peak situated at around 320 nm. They display a wide photoluminescence band with seven peaks in the range of 320–550 nm. The increase of the irradiation dose and RSH concentration results in a growth the ZnS nanocrystals and improves their optical performances. The optical as well as the structural characterizations confirmed the nanometric size of ZnS particles (Φ = 5–18 nm). When tested in photodegradation of Congo red under sun light, ZnS-zeolite Y catalyst exhibit high efficiency. For the experimental conditions: [ZnS-Y] = 0.5 g L−1; [CR] = 10 mgl−1+; pH = 6.6, the pseudo-first order constant is 0.076 min−1.

The purpose of this paper is to apply a nonlinear control law for an unmanned quadrotor helicopter. First, the quadrotor dynamic model is established using Newton-Euler formalism and taking into account various physical phenomena that can influence its dynamic behavior. Subsequently, Backstepping controller is designed. Its job is to generate commands to the four rotors to drive the quadrotor to track desired Cartesians positions and desired tilt angels. The designed methodology is based on the Lyapunov's theory of stability. This method was checked satisfactorily in simulation.

In this article we develop a new approach to control an omnidirectional mobile manipulator. This approach is based on a kinematic command structure and impedance control technique. First we define multiple control behaviors depending on the robot tasks. Two behaviors are considered here the synchronized one and the independent one. Each behavior mentioned above is described in terms of force and position models in order to allow each robot to regulate his corresponding behavior. In the case of synchronized situation, kinematic modelling is presented with particular emphasis on redundancy. We use the additional task concept to solve the control problem of these redundant holonomic systems by taking into account the external forces.

International audience; In this article we develop a new approach to control an omnidirectional mobile manipulator. The robot is considered as an individual agent aimed to perform robotic tasks described in terms of displacement and force interaction with the environment. A reactive architecture and impedance control are used to ensure reliable task execution in response to environment stimuli. The mechanical structure of our holonomic mobile manipulator is built from two joint manipulator mounted on an holonomic vehicle. The vehicle is equipped using three motorized axles with two spherical orthogonal wheels. The dynamics of the mobile manipulator robot is defined tacking into account the dynamical interaction between the base and the manipulator. Then we design a nonlinear controller for the robot using input-state linearization method. The control structure of the robot is built in order to demonstrate the main capabilities in navigation and obstacle avoidance. Several simulations were conducted to prove the effectiveness of our concept.

International audience; The use of an Electric Differential (ED) constitutes a technological advance in vehicle design along with the concept of more electric vehicles. EDs have the advantage of replacing loose and heavy mechanical differentials and transmissions with lighter and smaller electric motors directly coupled to the wheels via a single gear or an in-wheel motor. This paper deals then with an Electric Differential System (EDS) for an Electric Vehicle (EV) directly driven by dual induction motors in the rear wheels. A sensorless control technique is preferred to a position or speed encoder-based control one to reduce the overall cost and to improve the reliability. The EDS main feature is the robustness improvement against system uncertainties and road conditions. The EDS control performances are validated through experiments on a dSPACE-based test bench. The experimental results show that the proposed controller is able to track the speed reference and the curvature angle with good static and dynamic performances.

International audience; In this paper we are interested in the control of Doubly Fed Induction Machine (DFIM) using the Passivity Based Control (PBC). This work presents a solution to the problem of DFIM that requires a state observer. The proposed method shows very important advantages for nonlinear systems, especially in the trajectory tracking to achieve the needed DFIM performance. In the obtained results, the passivity provides high efficiency in DFIM based system, namely in its stability and robustness. An improvement behavior has been observed in comparison to the results given by the RST controller.

International audience; In this article we develop a new approach to control an omnidirectional mobile manipulator. This approach is based on a layered command structure and impedance control technique. First we define multiple control behaviors depending on the robot tasks. Two behaviors are considered here the synchronized one and the independent one. Each behavior mentioned above is described in terms of force and position models in order to allow each robot to regulate his corresponding behavior. In the case of synchronized situation, kinematic modeling is presented with particular emphasis on redundancy. We use the additional task concept to solve the control problem of these redundant holonomic systems by taking into account the external forces.

Three-dimensional linear BiGlobal instability of two-dimensional states over a periodic array of T-106/300 low-pressure turbine (LPT) blades is investigated for Reynolds numbers below 5000. The analyses are based on a high-order spectral/hpelement discretization using a hybrid mesh. Steady basic states are investigated by solution of the partial-derivative eigenvalue problem, while Floquet theory is used to analyse time-periodic flow set-up past the first bifurcation. The leading mode is associated with the wake and long-wavelength perturbations, while a second short-wavelength mode can be associated with the separation bubble at the trailing edge. The leading eigenvalues and Floquet multipliers of the LPT flow have been obtained in a range of spanwise wavenumbers. For the most general configuration all secondary modes were observed to be stable in the Reynolds number regime considered. When a single LPT blade with top to bottom periodicity is considered as a base flow, the imposed periodicity forces the wakes of adjacent blades to be synchronized. This enforced synchronization can produce a linear instability due to long-wavelength disturbances. However, relaxing the periodic restrictions is shown to remove this instability. A pseudo-spectrum analysis shows that the eigenvalues can become unstable due to the non-orthogonal properties of the eigenmodes. Three-dimensional direct numerical simulations confirm all perturbations identified herein. An optimum growth analysis based on singular-value decomposition identifies perturbations with energy growthsO(105).

International audience; This paper presents system analysis, modeling and simulation of an electric vehicle with different sensorless control techniques. Indeed, sensorless control is considered to be a lower cost alternative than the position or speed encoder-based control of induction motors for an electric vehicle. Two popular sensorless control methods, namely, the Luenberger observer and the Kalman filter methods are compared regarding speed and torque control characteristics. They are also compared against the well-known model reference adaptive system. Simulations on a test vehicle propelled by 37-kW induction motor lead to very interesting comparison results.

International audience; This paper presents system modeling, analysis, and simulation of an electric vehicle (EV) with two independent rear wheel drives. The traction control system is designed to guarantee the EV dynamics and stability when there are no differential gears. Using two in-wheel electricmotorsmakes it possible to have torque and speed control in each wheel. This control level improves EV stability and safety. The proposed traction control system uses the vehicle speed, which is different from wheel speed characterized by a slip in the driving mode, as an input. In this case, a generalized neural network algorithm is proposed to estimate the vehicle speed. The analysis and simulations lead to the conclusion that the proposed system is feasible. Simulation results on a test vehicle propelled by two 37-kW induction motors showed that the proposed control approach operates satisfactorily.

International audience; This paper proposes a Sensorless Direct Torque Control (SDTC) neural network traction control approach of an Electric vehicle (EV) without differential gears (electrical differential system). The EV is in this case propelled by two induction motor (one for each wheel). Indeed, using two electric in-wheel motors give the possibility to have a torque and speed control in each wheel. This control level improves the EV stability and the safety. The proposed traction control system uses the vehicle speed that is different from wheels speed characterized by slip in the driving mode, as an input. In terms of the analysis and the simulations carried out, the conclusion can be drawn that the proposed system is feasible. Simulation results on a test vehicle propelled by two 37-kW induction motors showed that the proposed SDTC neural network approach operates satisfactorily.

International audience; This paper presents system analysis, modeling and simulation of an EV with two independent rear wheel drives. The traction control system is designed to guarantee the EV dynamics and stability in case of no differential gears. Using two electrics in-wheel motors give the possibility to have a torque and speed control in each wheel. This control level improves the EV stability and the safety. The proposed traction control system uses the vehicle speed, which is different from wheels speed characterized by slip in the driving mode, an input. In this case, a generalized neural network algorithm is proposed to estimate the vehicle speed. In terms of the analysis and the simulations carried out, the conclusion can be drawn that the proposed system is feasible. Simulation results on a test vehicle propelled by two 37-kW induction motors showed that the proposed control approach operates satisfactorily.

International audience; This paper presents system analysis, modeling and simulation of an Electric Vehicle (EV) with three different control strategies: Field Oriented Control (FOC), Direct Torque Control (DTC), and DTC using Space Vector Modulation (DTCSVM). The objective is to assess the control strategy impact on the EV efficiency taking into account the vehicle dynamics. Indeed, among EV motor electric propulsion features, the energy efficiency is a basic characteristic that is influenced by vehicle dynamics and system architecture. Simulation tests have been carried out on a 37-kW EV that consists in an induction motor with a three-level IGBT inverter. Preliminary results seem to indicate that the DTC-SVM scheme is the best candidate.

International audience; Recently, the Permanent Magnet Synchronous Motor (PMSM) find a widespread utilization in modern adjustable AC drives. This is achieved by using current controlled Voltage Source Inverter (VSI) systems. Because of its ease implementation, fast current control response and inherent peak current limiting capability, hysteresis current control is considered as the simplest technique used to control the motor currents for AC machines. On the other hand, the ramp comparator controller has some advantages, such as limiting maximum inverter switching frequency to the carrier triangular waveform frequency and producing well-defined harmonics. In order to take advantage of the position features of both these two controllers, this paper presents the design and software implementation of a hybrid current controller. The proposed intelligent controller is a simultaneous combination and contribution of the hysteresis current controller and the ramp comparator. Comparisons using simulations on a 0.9-kW PMSM confirm that the proposed hybrid current controller gives better performance and has the advantage of conceptual simplicity. In particular, harmonic spectra of the stator current, obtained by using a fast Fourier transform, are used for comparison purposes.

International audience; As recent studies on the evolution of a technology indicate, the role of a standard, or dominant design, is highly significant in a number of contemporary industries such as computer, telecommunications and consumer electronics. Following Katz' and Shapiro's pioneering works (1985), our paper rationally evaluates the concepts and results developed over the past ten years in this field. It is grounded on a typology of two types of models: the first is based on users' anticipatory behaviour, and the second, on the collaborative behaviour of existing firms. The article initially discusses the specificity of network technologies, then analyses market standardisation models, and finally, studies the different actors models. Our conclusion builds upon existing works in network technologies. We next propose a research agenda