Liste des documents
Multiyear Load Growth Based Techno-Financial Li-ion Discharge and Corrosion Behaviors in a Microgrid Located in Algeria
The primary current-collector materials used in lithium-ion cells, aluminum and copper, are both susceptible to environmental degradation. Localized corrosion occurred on bare aluminum electrodes during simulated ambient-temperature cycling in an excess of electrolyte. The highly oxidizing potential associated with the positive electrode charge condition was the most important factor. In contrast to typical aqueous electrolyte pitting, each site was filled with a mixed metal/metal-oxide product, forming surface mounds or nodules. The status quo for relaying such confidence is economic and technical planning models, which are used to design microgrids and distributed energy resources DER. Long-term DER investments and short-term DER dispatch are typically determined by these models. This paper investigates the optimal cost analysis of a hybrid (photovoltaic-diesel) renewable energy system (HRES) in the Adrar region based on the Total Net Present Cost (TNPC). The Hybrid Optimization Model for Electric Renewable is used to perform the optimal cost analysis of HRES. Furthermore, the system is simulated for each time step for each year of the project's 20-year lifespan. The trade-off for this model, which captures battery storage levels from year to year, photovoltaic performance degradation, and diesel cost escalation above the inflation rate, is that the model is more precise, but the calculation takes longer. To begin, we ran the model without MultiYear and used the Optimizer to find the best system design. The optimal system for the single-year model includes a Danvest generator with 760 kW, 200 kWh of recommended Li-ion storage, and a slightly lower COE of $0.309/kWh. Various scenarios have been simulated, taking into account variations in the power production of the gasified biomass generator, and various solutions to ensure the balance generation/consumption have been analyzed. Voir les détails
Mots clés : corrosion, Diesel, Financial planning optimization, Hybrid energy system (HES), Li-ion battery, Multi-year planning, Microgrid, Photovoltaic, Technical planning optimization, total net present cost
Conception et réalisation d’un système d’imagerie ultrasonore commandé par carte FPGA.
Cette étude sera basée sur l’étude, la conception et la réalisation software et hardware d’un système de déplacement micrométrique à trois axes commandés par carte FPGA. Ce système permet un scanning des pièces par des transducteurs ultrasonores. Les signaux échographiques acquis sont acheminés vers un PC pour traitement et exploitation. Ce travail consiste aussi à implémenter des algorithmes sur MATLAB permettant de constituer des images ultrasonores et de les traiter pour détecter et localiser les éventuels défauts (ex. Fissures) dans les pièces examinées Voir les détails
Mots clés : déplacement micrométrique, carte FPGA, transducteurs ultrasonores
Diagnostic des défauts et contrôle non destructif des tôles magnétiques des transformateurs de puissance Pratique : Centre de Recherche en Technologies Industrielles
Les transformateurs de puissance sont des éléments clés des systèmes électriques et leurs défaillances sont très coûteuses. Cette thèse présente une étude comparative entre les caractéristiques électromagnétiques et thermiques d’une tôle magnétique saine d’un transformateur et une tôle corrodée. Les paramètres magnétiques extraits des boucles d'hystérésis telles que l'aimantation à saturation, l'aimantation coercitive, rémanente, la perméabilité magnétique et la zone d'hystérésis ont été analysées. Il a été démontré que la perte d'hystérésis dans le cas de l'échantillon avec corrosion est supérieure au cas de l'échantillon sans corrosion. Les paramètres électriques et thermiques sont également dégradés. Voir les détails
Mots clés : transformateur de puissance, corrosion, pertes, champ magnétique, distribution de la température.
Détection des feux de forêts en utilisant les images aériennes acquises par drone et le modèle YOLOv3
Forest fires in recent years have destroyed hundreds of thousands of hectares and caused the death of several people, these fires also have a significant economic cost. In this work, we propose an approach for an early wildfire detection, before their development into fires, because it is difficult to control them afterwards. The approach is based on the processing of aerial data acquired by unmanned aerial vehicles (UAV), and the automatic early wildfire detection, which allows to send an emergency alert directly to the relevant services and a to have a fast response. The technique used is based on transfer learning applied on a model of object detection which is YOLOv3, then validate the effectiveness of the model using the datasets of Flame, FiSmo and other images. The performances obtained in terms of Recall, F1-Score, Accuracy and Precision are respectively: 95.535%, 95.085%, 92.559%, and 96.428%. Voir les détails
Mots clés : Drone, Wildfire, Forests, YOLOv3, Detection.
Caractérisation mécanique jonctions d’assemblables :acier inoxydable 304L /alliages de types ZY-4
In order to avoid or minimize the appearance of the harmful phases in the zone of diffusion of the works employed aiming at controlling the flow of diffusion of the chemical elements through the interface, although studies are undertaken, the nature of the compounds, the formation kinetics of certain phases and the number of zones formed at the interface in the temperatures of their practices, between 950-1100°C, remain controversial. The data related to the compromises between the operating parameters of the welding thermal cycle, in particular the temperature and the holding time of the isothermal bearing during a direct bond Zy4/steel are not very developed in the literature. The recent results obtained on the shape of the interface and the nature of the phases formed which will serve as a basis for the interpretation of the results which will be obtained and presented in the last chapter. The ZPR consists of three layers regardless of the holding temperature The CI ~ 4 to 6 μm thick type - is located on the steel side. The thickness CII is practically independent of temperature, formed of a mixture of ε+Zr2 phases between 950 and 1020°C and of ε+-Zr phases for T=1050°C. Its thickness as well as its microstructure strongly depend on the holding temperature. The thickness of the ZPR evolves continuously up to 1020°C and increases drastically when T=1050°C . Results obtained from the evolution of the thickness of the reaction product zone as a function of residence time e=f, used to define the experimental parameters are used to select the thickness of the ZPR. During these steps the liquid fraction is gradually increasing and the thickness of CIII becomes drastically enlarged after 45 minutes of isothermal holding. Voir les détails
Mots clés : diffusion of the chemical elements, harmful phases
Caractérisation physico-chimique et électrochimique d’un soudage par friction rotative
The objective of This dissertation of master is to perform rotary friction welding . the first is to carry out a homogeneous welding by varying the speed of rotation and the second is to carry a heterogeneous welding AL2017/ Steel 304L . We follow a physico-chemical and electrochemical characterization on its two types of welding . Voir les détails
Mots clés : Rotary friction welding, AL2017/ Steel 304L, types of welding
Caractérisation microstructurale et micromécanique d’unassemblage X60/316L, réalisé par Cladding, après déformation par laminage à chaud.
The objective of this work is to study the behavior of an assembly composed of a high yield strength steel and an austenitic stainless steel made by the cladding process under the effect of hot working followed by recrystallization annealing. Microstructural and micromechanical characterizations were performed on the whole multi-material and at the interface. In the present work, we have highlighted the importance of understanding and mastering the aspects of phase transformation and recrystallization mechanisms in order to optimize the mechanical properties by thermal and/or thermomechanical treatment. Voir les détails
Mots clés : Cladding, HSLA steel, stainless steel, thermomechanical treatment, recrystallization, phase transformation, Microhardness, annealing.
Conception et réalisation d’un système d’imagerie ultrasonore commandé par carte FPGA
This research will be built on the study, the conception and the software and hardware realization of a micrometric displacement system with three axes, controlled by FPGA board. This system allows a scanning of the parts by ultrasonic transducers. The acquired ultrasound signals are sent to a PC for processing and exploitation. This work also consists in implementing algorithms on MATLAB allowing to constitute ultrasonic images and to process them in order to detect and locate the possible defects (ex.cracks) in the examined parts. Voir les détails
Mots clés : micrometric displacement, FPGA board, ultrasound transducers
Etude de la soudabilité de l'alliage d'aluminium 7075 soudé par le procédé de soudage par point par friction malaxage FSSW
The welding of metal structures and constructions in various industrial sectors is tending towards the intensive use of modernized welding processes such as FSSW. In order to reduce the weight of metallic devices and structures, the replacement of riveting by welding is considered in the current research. In the present work, the interest will be focused on the study of this process. Sheets in AA7075-T6 are welded using different speeds of rotation and depth of penetration, we have used several simple but effective analytical methods suitable for this type of research, such as mechanical tests, such as tensile tests and hardness tests, to determine the best properties for a good weld that can maintain the mechanical properties of the base materials. We also conducted a microscopic study to detect the different zones in welding position, and we reached zones, which are ZM ZAT ZATM These zones result from the heat generated by the friction that occurs between the welding tool and the aluminum plates. We show that increasing the speed of rotation and the depth of penetration of pawn increases the resistance of the weld joint. So we obtain a tensile force equal to 2.03 kN at a speed of 1800 rpm and a penetration value of 3.4 Voir les détails
Mots clés : ZM ZAT ZATM, welding of metal structures, FSSW, AA7075-T6
Elaboration et caractérisation des nanoparticules Ferrite/ Mg/Mn par co-précipitation
Nanosciences and nanotechnologies have experienced great growth over the past fifteen years, thanks to the development of new tools for elaboration, observation and analysis. This thesis focuses on the development of iron-based nanoparticles by the coprecipitation method with an experimental protocol and under different temperature and pH conditions. The characterization of the phases was carried out by X-ray diffraction, Infrared spectroscopy with Fourier Transform FTIR and Ultraviolet-visible spectroscopy. Voir les détails
Mots clés : Nanosciences and nanotechnologies, iron-based nanoparticles, X-ray diffraction