Bank of Extended Kalman Filters for Faults Diagnosis in Wind Turbine Doubly Fed Induction Generator

In order to increase the efficiency, to ensure availability and to prevent unexpected failures of the doubly fed induction generator (DFIG), widely used in speed variable wind turbine (SVWT), a model based approach is proposed for diagnosing stator and rotor winding and current sensors faults in the generator. In this study, the Extended Kalman Filter (EKF) is used as state and parameter estimation method for this model based diagnosis approach. The generator windings faults and current instruments defects are modelled, detected and isolated with the use of the faults indicators called residuals, which are obtained based on the EKF observer. The mathematical model of DFIG for both healthy and faulty operating conditions is implemented in Matlab/Simulink software. The obtained simulation results demonstrate the effectiveness of the proposed technique for diagnosis and quantification of the faults under study

Modeling and Simulation of the Variable Speed Wind Turbine Based on a Doubly Fed Induction Generator

This chapter presents the modeling and simulation results of variable speed wind turbine driven by doubly fed induction generator (DFIG). The feeding of the generator is ensured through its stator directly connected to the electrical grid and by its rotor connected to the grid through two power converters, which are controlled by the pulse width modulation (PWM) technique. This configuration is the most used in the wind power generation systems. For the variable speed operation of the studied system, the maximum power point tracking strategy is applied for the turbine, and the stator flux-oriented vector control is used for the generator. The MATLAB/Simulink software is used for the system modeling and simulation. For the wind velocity model, a random wind profile is simulated, and the turbine and the generator parameters are extracted from an existing wind turbine system in the literature. The obtained results are addressed in this chapter

La RSE et la contribution à la Performance Financière

In recent decades, the issue of corporate social responsibility has been the subject of several fruitful debates, both in the scientific and practical framework. Indeed, in this manuscript we will deal with an issue that we constantly encounter, but which differs from one context to another and from one managerial strategy to another. The issue relates to the impact of the integration of corporate social responsibility practices on financial performance, an issue that is mixed between proponents and opponents. This manuscript first deals with the continuous development of the notion of Corporate Social Responsibility (CSR) through the years and according to the visions of different authors, and then we have addressed the key concepts considered paramount for the outcome of our research. In a second plan, we will approach the notion of financial performance which has served us for the completion of a conceptual model carried out by us at the end of this article, allowing us to formulate the hypotheses related to our problematic in order to go towards the validation in a future moment. And finally, we will proceed to the presentation of two theories; namely the stakeholder theory, which has had an unparalleled impact on the organisational world, will come the agency theory, these two theories will serve us to understand the notion of CSR at the crossroads of scientific thought. And to conclude, we will present a conceptual model that we were able to build through the elements mentioned above, allowing us to know the variables involved in achieving financial performance through the integration of CSR practices, mainly with standards and certifications.     JEL Classification: L20, L21. Paper type: Theoretical Research.Au cours des dernières décennies, la question de responsabilité sociale (ou sociétale) des entreprises fait l’objet de plusieurs débats fructueux, que ce soit dans le cadre scientifique ou pratique. En effet, au niveau de ce manuscrit nous traiterons une problématique que nous rencontrons constamment, mais qui diffère d’un contexte à un autre et d’une stratégie managériale à une autre. La question se rapporte à l’impact de l’intégration des pratiques de la responsabilité sociale des entreprises sur leur performance financière, une problématique mitigée entre partisans et contradicteurs. Ce manuscrit traite en prime abord le développement continu de la notion de Responsabilité Sociale des Entreprises (RSE) à travers les années et selon les visions de différents auteurs, puis nous avons abordé les concepts clés estimés primordiaux pour l’aboutissement de notre recherche. Dans un second plan, nous allons aborder la notion de performance financière qui nous a servi pour l’accomplissement d’un modèle conceptuel effectué par notre soin à la fin de cet article, nous permettant de formuler les hypothèses liées à notre problématique afin d’aller vers la validation dans un moment futur. Et enfin, nous allons procéder à la présentation de deux théories ; à savoir la théorie des parties prenantes, ayant eu un impact sans égal dans le monde organisationnel, par la suite ; viendra la théorie d’agence, ces deux théories nous serviront à comprendre la notion de RSE au carrefour de la pensée scientifique. Et pour conclure, nous présenterons un modèle conceptuel que nous avons pu constituer à travers les éléments cités ci-dessus, nous permettant de connaitre les variables en jeu pour l’atteinte de la performance financière à travers l’intégration des pratiques RSE, principalement avec les normes et certifications.     Classification JEL : L20, L21. Type de l’article : Article théorique

SHE Control for PV System Connected to the Grid

In this article, we have proposed a new control of a PV system connected to the grid. The goal is to reduce current and voltage harmonicsfor increasing the quality of delivered energy. First, we have modeled a PV panel. Then we have dimensioned the BOOST converter by finding L and C values. Next, we have used Perturb and Observe (P&O) Maximum Power Point Control (MPPT) to improve energy efficiency. Finally, We have developed a control of single-phase H-bridge inverter in order to eliminate the 3rd,5th,7th and 9th harmonics order, and added an LCLTo connect the PV inverter to the grid, an LCL betweenthe inverter and the grid. Theperformance of the proposed system was tested by computing spectrum and THD usingMatlab/Simulink software. The proposed architecture provides better Total Harmonic Distortion (THD) which satisfy the EN50160 requirement the THD must be less than 4.66%. We found that THD was decreased from 61.93% to 0.04%

Reaction of some rapeseed (Brassica napus L.) genotypes to different drought stress levels during germination and seedling growth stages☆

Drought is a major abiotic stress that affects seed germination and plant growth in arid and semi-arid regions. Rapeseed is an oilseed crop adapted to Mediterranean area; however, it is reported that it is sensitive to water stress occurring during seed germination. In this study, we investigated how seed germination and early seedling growth of six rapeseed genotypes were influenced by different water stress levels. In addition to the control (absence of drought stress), three drought levels were simulated using three osmotic potentials of polyethylene glycol (PEG-6000), −9, −10 and −11 bars. A completely randomized design with three replications was used for this experiment. Germination percentage (GP), shoot length (SL), root length (RL), shoot elongation rate (SER) and root elongation rate (RER) were determined to evaluate the genotypes response to PEG-induced drought stress. Results showed drought stress, genotype and interaction stress × genotype had a significant effect on the studied parameters. GP decreased with the increase in stress level. The genotype ‛Nap9’ was the most interesting, having the highest GP values, namely 63.33, 62.67 and 28% under the stress levels −9, −10 and −11 bars, respectively. The genotype ‛H2M-5’, which ranked second with respect to this parameter, was statistically comparable to ‛Nap9’. Also, SL, RL, SER and RER decreased with the increase in drought stress level. However, the studied genotypes reacted differently to various water stress levels. Once again, the genotype ‛H2M-5’ exhibited the highest average RL and RER under all drought levels. Particularly, for severe drought conditions (−11 bars), ‛H2M-5’ had an average RL of 1.54 cm and RER of 0.36 cm/d. Field evaluation under controlled conditions is needed to confirm findings of the present experiment. The mutant ‛H2M-5’ could be a valuable and promising germplasm for developing a performant and adapted variety to be designed for harsh environments particularly characterized by early drought coinciding with germination and seedling growth stages

Liver damage in COVID-19 infected patients: A series of 299cases: Mohammed VI Hospital University experience

COVID-19 infection is a viral infection with a particular tropism for lung tissue. However, organs involvementother than lung have been reported. Liver is also reported to be injured during infection by COVID-19 infection, which is most often revealed by an early elevation of alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST).Involvement of liver could be explained by interaction of the virus with the hepatocytes directly through infecting them or through ischemia secondary to lung lesions. Drugs used in COVID-19 management have also been reported to be hepatotoxic.Our work is a retrospective study that was about 299 COVID-19 infected patients. We aim through this study to report the occurrence of liver damage in COVID-19 infection. All subjects of our study have been admitted to the Oujda Mohammed VI university hospital of Morocco. All biological explorations in our series have been performed in the central laboratory of the same establishment

The HoxD cluster is a dynamic and resilient TAD boundary controlling the segregation of antagonistic regulatory landscapes

The mammalian HoxD cluster lies between two topologically associating domains (TADs) matching distinct enhancer-rich regulatory landscapes. During limb development, the telomeric TAD controls the early transcription of Hoxd genes in forearm cells, whereas the centromeric TAD subsequently regulates more posterior Hoxd genes in digit cells. Therefore, the TAD boundary prevents the terminal Hoxd13 gene from responding to forearm enhancers, thereby allowing proper limb patterning. To assess the nature and function of this CTCF-rich DNA region in embryos, we compared chromatin interaction profiles between proximal and distal limb bud cells isolated from mutant stocks where various parts of this boundary region were removed. The resulting progressive release in boundary effect triggered inter-TAD contacts, favored by the activity of the newly accessed enhancers. However, the boundary was highly resilient, and only a 400-kb deletion, including the whole-gene cluster, was eventually able to merge the neighboring TADs into a single structure. In this unified TAD, both proximal and distal limb enhancers nevertheless continued to work independently over a targeted transgenic reporter construct. We propose that the whole HoxD cluster is a dynamic TAD border and that the exact boundary position varies depending on both the transcriptional status and the developmental context. Press

Syndromes microdélétionnels (syndrome de Williams et syndrome de la délétion 22q11) au CHU Hassan II de Fès: à propos de 3 observations

Les syndromes microdélétionnels sont définis par la présence d’une anomalie chromosomique de taille mineure (inférieure à 5 mégabases) ou aneusomie segmentaire, décelable par cytogénétique moléculaire (FISH : Fluorescent in Situ Hybridization). Les syndromes microdélétionnels représentent des syndromes cliniques avec des phénotypes suffisamment caractéristiques pour être reconnus cliniquement. Actuellement la FISH est la technique de choix pour rechercher ces syndromes. Plusieurs syndromes microdélétionnels peuvent être confirmés aisément, les plus recherchés sont Le syndrome de Williams (microdélétion en 7q11.23) et le syndrome de la délétion 22q11 (microdélétion en 22q11.2). Le syndrome de Williams est caractérisé par une anomalie du développement qui associe un retard psycho-moteur, une dysmorphie du visage évocatrice et un profil cognitif et comportemental spécifique, une sténose aortique supravalvulaire -SASV- le plus souvent. Le Syndrome de la délétion 22q11 se caractérise par l’association de plusieurs malformations d’expression variable: une cardiopathie congénitale de type conotroncal, une dysmorphie faciale discrète mais caractéristique et une hypoplasie du thymus et des parathyroïdes. Nous rapportons nos premières observations au CHU Hassan II confirmées par FISH : Syndrome de la délétion 22q11 (n:2) et un syndrome de Williams. Le but de cet article est la mise à jour de nos connaissances sur ces deux syndromes et la mise en valeur du rôle de la cytogénétique moléculaire dans le diagnostic et le conseil génétique des syndromes microdélétionnels

Liquid biopsy beyond cancer: a miRNA detection in serum with electrochemical chip for non-invasive coeliac disease diagnosis

Coeliac disease is a very common autoimmune disease estimated to affect 1 in 100 people worldwide. It occurs in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine, and it is accurately diagnosticated through duodenal biopsy, an invasive diagnostic method. The liquid biopsy, generally used for monitoring cancer, is an appealing alternative even for autoimmune pathology such as coeliac disease, allowing for detecting disease progression or resistance to treatment. For this reason, an electrochemical peptide nucleic acid (PNA) device combined with a smartphone-assisted potentiostat for non-invasive coeliac disease diagnosis is proposed, by measuring the selected overexpressed miRNA-486-5p in serum, enlarging the application of liquid biopsy in nontumor pathologies. For highly sensitive detection, the polyester-based printed sensor is nanomodified with gold nanoparticles and a synthetic customized PNA probe. The designed sensor can detect the target analyte in the range of 10–100 nM with a limit of detection of 0.7 nM by measuring the variation of the response of the electrochemical mediator hexaammineruthenium in the presence of PNA–miRNA duplex on the nanostructured working electrode surface. The analyses testing serum samples are found in agreement with ones obtained by realxtime quantitative polymerase chain reaction (RT-qPCR), demonstrating the reliability of this innovative electrochemical chip developed