DSpace Collection:
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/2698
2024-03-28T10:40:51ZDetection system parameters' effects on amplitude and spectral features of SFAP generated from a cylindrical multilayer volume conductor
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/13361
Titre: Detection system parameters' effects on amplitude and spectral features of SFAP generated from a cylindrical multilayer volume conductor
Auteur(s): Messaoudi, Noureddine; Belkacem, Samia
Résumé: The electromyographic (EMG) signal represents the electrical variations of muscles activities. It can be detected on the skin surface above the aimed muscle. The assessment of the effects of anatomical, physiological and detection system parameters on the shape of the detected surface EMG signal is more evident by using the signal generated by a single fibre action potential (SFAP). Amplitude and spectral characteristics of the detected signal are good estimators of the effects of the anatomical, physiological and detection system parameters on the shape of generated signal. In this work, we interpret the effects of the detection system parameters (the fibres inclination angle and the inter-electrode distance) on the average rectified value (ARV) and on the median frequency (MDF) of the surface SFAP signal generated in a multilayer cylindrical volume conductor contains the limb muscle. The potential is detected on the skin surface with a detection system which is constituted by eight 1D and 2D spatial filters and a grid of nine point electrodes. We show that the increase of the fibres inclination angle decreases the ARV and the MDF of the simulated signal and that the increase of the inter-electrode distance increases them.2023-01-01T00:00:00ZApplication of Synchro-Phasor Measurement Unit in Smart Grid Including Renewable Energy
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/11872
Titre: Application of Synchro-Phasor Measurement Unit in Smart Grid Including Renewable Energy
Auteur(s): Mahboubi, Meriem; Ouadi, Abderrahmane
Résumé: Renewable energy is one of the most abundant energies in our planet. In order to satisfy the world demand of electrical energy, solar and wind energy may be used. Identical to all other types of power generation plants, the integration of these renewable energy sources in smart power grid has an impact on its operation. Thus, when the electrical power is injected into the power grid by these energy sources, the system electrical parameters must be well monitored for synchronization purpose. This can be accomplished with the aid of synchro-phasors measurement units. The phase angle of the utility is a critical parameter for the operation of power devices feeding power into the grid such as PV and wind energy inverters. There are many techniques to obtain the grid phase angle such as the zero-crossing detection and the orthogonal phase locked loop. This research work discusses the use of Phasor Measurement Unit (PMU) for providing this important parameter to system synchronization in the case of high penetration of solar or wind energy in the power grid.2022-01-01T00:00:00ZChimie en solution Tome 1 : Les Acides et les Bases Cours &TD
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/11637
Titre: Chimie en solution Tome 1 : Les Acides et les Bases Cours &TD
Auteur(s): BOUZID, M.; Ouradi, A. (Co-auteur); Benmounah, M. (Superviseur)
Résumé: Je trouve implicite et instructif, l’introduction de ce chapitre « Les acides et les
bases » sur la base d’articles récents, publiés dans des journaux de référence. Des articles
qui présentent, à juste titre, le chapitre « des acides et des bases » depuis le coeur de la
biochimie médicale, fondement de la physiologie. La lecture de ce type de publication est
un complément avéré d’information et d’actualisation pour les étudiants en sciences
médicales et sciences de la vie, autant pour les enseignants et chercheurs dans le domaine.
La chimie de part ces composantes : la structure de la matière, la chimie
organique, la thermodynamique et la chimie en solution, prédispose l’étudiant destiné à la
biologie, la pharmacie, la médecine…justement, à saisir le fondamental de ces cycles
complexes de la vie. Cette préparation pédagogique est déterminante pour former un
esprit lucide, digne de ces disciplines.....2023-01-01T00:00:00ZPMU Phasor Estimation Using Different Techniques
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/6537
Titre: PMU Phasor Estimation Using Different Techniques
Auteur(s): Bentarzi, Hamid; Ouadi, Abderrahmane
Résumé: Many models of phasor measurement units (PMU) have been implemented; however, few dynamic models have been developed when the power system parameters change. It is necessary to use a method that can somehow estimate the frequency and correct the phasors. The conventional way to determine frequency is to detect zero crossings per unit time. However, this method has many drawbacks such as high cost and low accuracy. Also, after the frequency determination, the phasor should be corrected by suitably modifying the algorithm without omitting any data. This chapter presents different estimation techniques such as discrete Fourier transform (DFT), smart discrete Fourier transform (SDFT) that may be used to estimate the phasors. These estimated values would be incorrect if the input signals are at an off-nominal frequency and the phase angles would drift away from the true values. To correct this issue, first of all, the off-nominal frequency has been estimated using different techniques such as least error squares and phasor measurement angle changing, and then it is used to correct the phasors2021-01-01T00:00:00Z