Design and Implementation of Takagi-Sugeno Fuzzy Tracking Control for a DC-DC Buck Converter

This paper presents the design and implementation of a Takagi-Sugeno (T-S) fuzzy controller for a DC-DC buck converter using Arduino board. The proposed fuzzy controller is able to pilot the states of the buck converter to track a reference model. The T-S fuzzy model is employed, firstly, to represent exactly the dynamics of the nonlinear buck converter system, and then the considered controller is designed on the basis of a concept called Virtual Desired Variables (VDVs). In this case, a two-stage design procedure is developed: i) determine the reference model according to the desired output voltage, ii) determine the fuzzy controller gains by solving a set of Linear Matrix Inequalities (LMIs). A digital implementation of the proposed T-S fuzzy controller is carried out using the ATmega328P-based Microcontroller of the Arduino Uno board. Simulations and experimental results demonstrate the validity and effectiveness of the proposed control scheme

Metodología de rehabilitación de patrimonio histórico en la ciudad de Skikda, Argelia

Proyecto de intervención para la rehabilitación de un conjunto de edificios en la ciudad costera de Skikda (Argelia), a partir de la colaboración Universidad/Empresa. El proyecto ofrece ciertas singularidades y puede servir como ejemplo de una metodología de actuación cuando se acometen trabajos de cierta envergadura. En este caso, los trabajos han consistido en elaborar toda la documentación necesaria para la elaboración de los proyectos de intervención, estableciendo además una serie de relaciones entre profesionales, el desarrollo de trabajos de investigación, y el diseño e impartición de programas de formación en rehabilitación específicos para los técnicos locales. Estos trabajos, liderados por el personal docente e investigador (PDI) de la Universitat Politècnica de Catalunya (UPC), han consistido en la impartición de un curso de formación en rehabilitación de 4 meses de duración para los estudiantes de Máster en Arquitectura y técnicos locales; la asesoría técnica para la puesta en marcha de un laboratorio local para la caracterización de materiales de construcción; la asesoría y realización de la campaña de ensayos sistemática de caracterización de materiales; asesoría en la aplicación de normativa internacional para el cálculo estructural; la investigación y redacción de un estudio histórico de la ciudad; y un Plan de color de las fachadas para la posterior propuesta de intervención cromática del conjunto. Toda la información generada se ha puesto a disposición de la administración local y de los profesionales encargados de intervenir en el patrimonio arquitectónico de la ciudad, para que así puedan elaborar sus propuestas de rehabilitación sobre unas bases científicamente documentadas. Consideramos que esta experiencia puede ser replicable en otros proyectos internacionales similares, ya que el conocimiento que se genera desde la Universidad aporta rigor metodológico, herramientas de análisis y transferencia de conocimiento hacia la sociedad, además de añadir valor a los trabajos de diagnosis y rehabilitación de edificios históricos y patrimoniales. La colaboración universidad/empresa y la implicación de estudiantes, profesionales, tanto locales como externos, enriquece los proyectos, ayuda al progreso del conocimiento y refuerza las relaciones entre culturas y sociedades. This text aims to resume the experience of collaboration between the University and the Private Sector (AQUIDOS office) in the context of a project of rehabilitation of several damaged blocks in the coastal city of Skikda, in Algeria. The project shows different singularities and it is a clear example in terms of methodology of intervention, when dealing with urban projects and heritage. In this case, the works consisted in preparing all the necessary previous documentation in order to elaborate the specific projects of intervention, in stablishing at the same time a relationship between different professionals, carrying out different research studies and in designing and teaching a specific rehabilitation program oriented to local practitioners. All these works, leaded by different researchers and professors of the Universitat Politècnica de Catalunya (UPC), consisted in: teaching a specific course about rehabilitation techniques during 4 months oriented to Mater Program Students and local practitioners; in a technical assessment to start up a new local Laboratory of Construction Materials and a continuous assessment and experimental campaign about the mechanical characterization of the materials; in a entire structural assessment about implementing international and local standards and, finally, in researching about the history of the city of Skikda and elaborating a specific plan of color of the facades to decide the final intervention. All the documentation coming from this project is in hands of local Administration and those professionals who are in charge of the real project, in order that they can define the final solutions based on scientific experiments and real data. We truly consider that this experience can be repeated in other similar international projects, since the knowledge provided by the University in these cases is a source of methodological rigor, analytical tools and know‐how transfer to the society, as well as an added value to any project involving heritage. The active collaboration between University and the Private Sector, the implication of students and practitioners (both local and foreigners), always enriches these projects and pushes the progress of knowledge and the relationships between different cultures.Peer ReviewedPostprint (published version

Ethnobotanical Study of Antihemorrhagic Plants in the Skikda Region (North East Of Algeria)

Our survey was carried out at the level of 17 Municipalities of the Province of Skikda. Questionnaire sheets were distributed to 55 herbalists and 350 locale population (informants). The processing of survey data with the local population shows us that women (52 %) have more knowledge of phytotherapy compared to men (48 %) with a fairly high level of education. For the herbalists, we found that most are men (85.45 %) aged between 31-40 years (29.09 %) and 41-50 years (25.45 %), and with level of university study (36.36 %). On the other hand, 52.73 % of herbalists said they inherited their knowledge from their families and only 20 % of them were trained in institutes. From a pharmacological point of view, the leaves are the most used part of the plant (81.76 %), prepared in the form of different recipes generally intended for local use (66.65 %), while some plants can be used alone, or with honey and olive oil. Regarding the diversity of species, we have identified 24 antihemorrhagic species among them the most cited are; Dittrichia viscosa (L.) Greuter. (Asteraceae) (137 citations), Chamaecytisus triflorus (Lam.) Skalická (Fabaceae) (81 citations) and Angelica archangelica L. (Apiaceae) (72 citations). Finally, this study is interesting and forms a starting point for researchers and must be completed by in vitro and in vivo antihemorrhagic tests

The contribution of GIS in the quantification of the evolution of Skikda's coastline between 1960 and 2002 and the impact of developments

Le littoral est considéré comme un lieu de grande complexité physique et socioéconomique. La densité de population et la concurrence des activités humaines ont engendré des dégradations sur ce milieu. L’érosion côtière est un phénomène naturel de l’évolution morphologique des littoraux. Mais ces dernières décennies, il est devenu un risque flagrant qui menace les différents types de constructions (ports, équipements touristiques, zones urbaines…). Alors l’analyse et le suivi de l’évolution du trait de côte ainsi que les recherches traitant l’impact des aménagements sur le milieu côtier permettent de définir une meilleure gestion et planification littorale. Cet article se focalise sur le suivi de l’évolution dynamique du littoral en utilisant les outils de géomatique. L’analyse diachronique de l’évolution du littoral de Skikda montre une forte variabilité morphologique qui se manifeste par un recul net du trait de côte, menaçant sérieusement la stabilité des infrastructuresThe coastline is considered as a place of great physical and socioeconomic complexity. The concentration and competition from human activities have caused damage to the environment. Coastal erosion is a natural phenomenon of the morphological evolution of coastlines. However, in recent decades this phenomenon has become a very important coastal risk that threatens different types of constructions (harbor, tourist facilities, urban area…). Therefore, the analysis and monitoring of the evolution of the coastline and research on the impact of developments on the coastal environment allow defining a better management and coastal planning. This article presents the dynamic evolution of the coastline using geomatics tools. The diachronic analysis of the evolution of Skikda's coastline shows a strong morphological variability manifested by a net decline of the coastline, seriously threatening the stability of the infrastructures.Le littoral est considéré comme un lieu de grande complexité physique et socioéconomique. La densité de population et la concurrence des activités humaines ont engendré des dégradations sur ce milieu. L’érosion côtière est un phénomène naturel de l’évolution morphologique des littoraux. Mais ces dernières décennies, il est devenu un risque flagrant qui menace les différents types de constructions (ports, équipements touristiques, zones urbaines…). Alors l’analyse et le suivi de l’évolution du trait de côte ainsi que les recherches traitant l’impact des aménagements sur le milieu côtier permettent de définir une meilleure gestion et planification littorale. Cet article se focalise sur le suivi de l’évolution dynamique du littoral en utilisant les outils de géomatique. L’analyse diachronique de l’évolution du littoral de Skikda montre une forte variabilité morphologique qui se manifeste par un recul net du trait de côte, menaçant sérieusement la stabilité des infrastructures

A MEMS-based solid propellant microthruster array for space and military applications

Since combustion is an easy way to achieve large quantities of energy from a small volume, we developed a MEMS based solid propellant microthruster array for small spacecraft and micro-air-vehicle applications. A thruster is composed of a fuel chamber layer, a top-side igniter with a micromachined nozzle in the same silicon layer. Layers are assembled by adhesive bonding to give final MEMS array. The thrust force is generated by the combustion of propellant stored in a few millimeter cube chamber. The micro-igniter is a polysilicon resistor deposited on a low stress SiO2/SiNx thin membrane to ensure a good heat transfer to the propellant and thus a low electric power consumption. A large range of thrust force is obtained simply by varying chamber and nozzle geometry parameters in one step of Deep Reactive Ion Etching (DRIE). Experimental tests of ignition and combustion employing home made (DB+x% BP) propellant composed of a Double-Base and Black-Powder. A temperature of 250 therefore degrees C, enough to propellant initiation, is reached for 40 mW of electric power. A combustion rate of about 3.4 mm/s is measured for DB+20% BP propellant and thrust ranges between 0.1 and 3,5 mN are obtained for BP ratio between 10% and 30% using a microthruster of 100 mu m of throat wide

Algerian development and urbanisation : a case study of Skikda

Abstract: p.x

Assessment of metal trace elements in the echinoderm Paracentrotus lividus from the North-Eastern coast of Algeria

The echinoderm sea urchin Paracentrotus lividus Lamarck, 1816 (Echinodermata, Echinoidea) is a good species to be used in environmental and toxicology research, in particular as a heavy metal bio-indicator. Our study’s objective is to evaluate the amounts of Zn, Pb, Fe, and Cu in sea urchin specimens collected from the coast of Skikda (Northeast Algeria) in order to validate the fact that sea urchins are good indicators of metal pollution and can be used effectively for environmental biomonitoring. To realize our objectives, three sampling sites were chosen based on suspected forms and sources of contamination. The main physicochemical parameters of the seawater were measured to determine their quality. 15 specimens of urchins in each station were obtained from exposed rocky surfaces and transported to the laboratory. Before dissection, the biometric parameters and the total wet weight were determined. The soft organs (gut and gonads) of individuals were separated and utilized to evaluate the levels of heavy metals. The condition index and metal indices were also determined. Our study confirmed that P. lividus may be considered a valuable bioindicator of heavy metal contamination in marine ecosystems. The results show that the amounts of heavy metals differed significantly between stations. Samples taken from the Larbi Ben M’hidi station showed greater amounts of Pb, Zn, and Cu. These amounts are above the recommended limits for fish and aquatic animals. Also, the heavy metals found in sea urchins vary depending on the physicochemical parameters, trace metals in the seawater, and the individual biometric parameters. These higher concentrations of metals in seawater and in P. lividus individuals at the Larbi Ben M’hidi station are largely caused by the construction of a massive oil industry complex and terminal with several refineries and petrochemical units near this station, as well as by a considerable amount of domestic wastewater. Finally, to avoid this metallic pollution risk, it is necessary that permanent controls be imposed as soon as possible. Urban and industrial wastes must be treated before being released, in the hope of reducing future metal concentrations

Assessment of the G model adopted in maintenance management within the oil sector institutions in Skikda (Sonatrach) and its role in enhancing maintenance operations

This study delves into the maintenance model G adopted by the maintenance management within the oil sector institutions in Skikda (Sonatrach). Recognized as a strategic autonomous entity that encompasses everything from planning to control, this management sector is pivotal in maximizing and leveraging available production energies based on scientific diagnostics and structured execution. This is instrumental in achieving reduced maintenance costs. Moreover, the study seeks to implement this model within a comprehensive maintenance framework that encapsulates the essential pillars of maintenance management: robust organization, effective human resource management, clear objectives and strategies, along with the support and commitment of top management. A field study examining the various phases of implementing preventive and corrective maintenance using the G model revealed that this function often lacks the requisite emphasis and care. This is attributed to the maintenance management's failure to effectively implement the G model as stipulated by the company, a deficient awareness in activating maintenance management perceived merely as a cost-reduction tool, coupled with a neglect of the human resources pillar and the lack of support and commitment from senior management

ADAPTABILITY SKILL AND ITS ROLE IN THE SUCCESSFUL IMPLEMENTATION OF SAP SYSTEM IN ALGERIAN HYDROCARBONS SECTOR: CASE STUDY IN THE SKIKDA HYDROCARBONS SECTOR

Purpose: This study evaluates the prevalence of adaptability skills among personnel at Skikda hydrocarbons institutions and investigates the strategies employed to cultivate these skills. The aim is to understand their significance in the effective implementation of the SAP system within the organization.   Methodology: The research utilized a descriptive analytical approach, involving the dissemination of questionnaires to employees within the Skikda hydrocarbons sector. A total of 61 out of 70 distributed forms were retrieved and subsequently analyzed using the SPSS software.   Results: Analysis revealed that the respondents exhibit adaptability skills, characterized by the acquisition of related personal traits. Additionally, it was noted that management is actively involved in enhancing these skills among the workforce.   Practical Implications: Based on the findings, the study recommends that management should consistently apply change management strategies and foster innovation by empowering employees with a stake in decision-making processes. Such measures are anticipated to significantly enhance the prospects for a successful SAP system implementation..   Originality/Value: This research contributes to the understanding of adaptability skills in the hydrocarbons sector and highlights the critical role these skills play in the successful deployment of complex information systems like SAP. It underscores the necessity of strategic employee involvement and proactive skill enhancement in organizational change processes

Marine pollution effects on the reproduction process of Perinereis cultrifera (Annelida, Polychaeta) in Algeria

The Mediterranean Sea is one of the busiest areas worldwide in terms of maritime activity and faces considerable anthropogenic disturbances, such as pollution by hydrocarbons and heavy metals. This study evaluated the environmental status of three sites on the Algerian coast using the annelid polychaete Perinereis cultrifera as a biomonitoring sentinel species. It included different reproductive parameters such as oocyte diameter, frequency distributions, sexual maturity index, biochemical quantitative parameters represented by the vitellogenins and vitellins, and a histological study of the coelome during the reproductive period. The results showed that the females collected from El-Kala (healthy site) have the highest diameter 304.1 ± 24.3 μm during April but the values were increased in Annaba 290.0 ± 21.0 μm and Skikda 245.3 ± 26.7 μm. Significant differences were observed between worms from the three study sites during the three months of the study. Moreover, the size-frequency indicated that a relatively high proportion of females containing mature oocytes was found in April in females collected at El-Kala 52.4%, 46.4% in females collected at Annaba and 36.7% in females collected at Skikda. In addition, regarding the sexual maturity index, the highest values were recorded in April (3.8, 2.9, and 1.9) at the El-Kala, Annaba, and Skikda study sites. However, the biochemical analysis demontrated that the highest mean concentration of vitellogenin was in females of El-Kala (5.3 ± 0.3 µg/mg of coelomic fluid) in April, and the lowest mean concentration was measured in females of Skikda (1.5 ± 0.2 µg/mg of coelomic fluid). Therefore, the highest mean concentration of vitellin was measured in females of El-Kala (4.4 ± 0.2 µg/mg of oocytes) in April, while the lowest mean concentration of vitellin was measured in females of Skikda (1.02 ± 0.2 µg/mg of oocytes) in May. Significant differences were observed between worms from the three sites during the three months of the study. Furthermore, histological observations revealed that oogenesis was asynchronous, with oocytes at different stages of vitellogenesis simultaneously present. The structure of the oocytes of females collected at El-Kala showed intense vitellogenic activity due to the presence of very dense yolk cells. In contrast, the oocytes of the females collected from the two polluted sites (Annaba and Skikda) were small, vitellogenesis presented low intensity, and yolk cells were less frequent at the periphery and less uniform at the cytoplasmic mass; the nucleus was smaller, indicating a slower vitellogenic activity. These observations confirm the previously obtained results