Firdaws Gherraz , Khadidja Tebbakh , Nasredine Bouache

كلية الاداب واللغات-جامعة محمد الصديق بن يحيى - جيجل · الجزائر

Ce travail de recherche s’intitule « analyse sémiologique des logos des chaînes télévisées algériennes » et s’inscrit dans le cadre de la recherche en sémiologie. A partir de l’analyse d‘un corpus de 16 logos de chaînes de télévision algérienne, nous avons cherché à comprendre les mécanismes de fonctionnement et, partant, de signification de ces objets. Pour ce faire, nous nous sommes appuyées sur le modèle de Roland Barthes afin d’obtenir des résultats convaincants pour répondre aux interrogations venant à notre esprit

حسين قادري, ميلود العطري

كلية الحقوق والعلوم السياسية-جامعة باتنة 1 - الحاج لخضر · الجزائر

حنين صباح عبدالصمد, شيماء جبار ريسان

كلية التربية للعلوم الصرفة-جامعة البصرة · العراق

أحمد المالح , غازي ترجمان , محمد نور أحمد صباح لبابيدي

المعهد العالي للعلوم التطبيقية والتكنولوجيا‎ · سوريا

تهاني خلف الله أحمد علي, زكي الدين محمد الطيب الحسن

كلية الدراسات العليا-جامعة السودان للعلوم والتكنولوجيا · السودان

The wind energy is one of the fastest growing renewable sources, it is improvement and conversion technology has led to a fast development of wind power generation in recent years. Accordingly, this thesis deals with vector control of doubly fed induction generator (DFIG) connected to the grid. Control of (DFIG) based wind turbines needs to pay special attention to the distorted voltage operation scenario. Apart from the normal operation of the wind turbine, the designed control must be prepared to tackle problematic situations derived from grid voltage disturbances. These grid voltage disturbances can be of different natures (voltage dips, imbalances, harmonics, etc.) depending on the characteristics of the electric grid itself vector control has been simulated using MATLB Simulink. Simulation results are presented to validate the proposed controllers. The performance analysis of a (DFIG) driven by a wind turbine has been described. The dynamic equation of (DFIG) has been considered and the results show that DFIG performance proved to be more reliable and stable when connected to grid side with the proper converter control systems.

Brahim Admou, مراد شقراوي

كلية الطب والصيدلة - مراكش-جامعة القاضي عياض · المغرب

سمية هلال , عفاف موسوس , قاشي علال

كلية العلوم الاقتصادية والتجارية وعلوم التسيير-جامعة اكلى محند أولحاج - البويرة · الجزائر

Ahmet F. Aysan, Zhamal Nanaeva

كلية الدراسات الإسلامية-جامعة حمد بن خليفة · قطر

The thesis consists of five essays that examine the dynamics of Metaverse markets and financial services within this emerging virtual environment. It aims to explore the opportunities and challenges associated with advancing conventional and Islamic financial services within virtual environments. The first essay employs bibliometric analysis to study scholarly publications in the field of finance within the Metaverse. Through a systematic examination of 267 documents, facilitated using Biblioshiny and VOSviewer software tools, this study provides a comprehensive overview of the academic landscape and identifies the gaps in extant literature. The study highlights the most influential works and authors, setting the stage for future research in this evolving domain. The second essay utilizes the novel Quantile Vector Autoregressive (QVAR) model to analyze the inter connectedness of volatility between the Metaverse market, represented by the Global Metaverse Index, and other pivotal financial markets, including Gold, Crude Oil, Bitcoin, Nasdaq, and the Volatility Index. This analysis demonstrates a significant level of interconnectedness at extreme quantiles and identifies Nasdaq as a primary transmitter of volatility to the Metaverse market. The third essay applies the Wavelet Local Multiple Correlation (WLMC) method to evaluate the effects of economic uncertainties on Metaverse markets. The findings reveal that Metaverse indices exhibit dynamic responses to the volatility of the Twitter Economic Uncertainty Index. Furthermore, the study determines a positive correlation between the gold volatility index and Metaverse indices, whereas the correlation with the oil volatility index appears negative. Moreover, Bitcoin displays an insignificant correlation with Metaverse indices. The fourth essay conducts a qualitative examination of the Metaverse market, presenting its principal sectors and key enablers. It draws analogies between the global transition to virtual reality and significant historical transformations, such as the Industrial Revolution. It articulates the primary drivers expected to influence the future development of virtual reality and financial services within the Metaverse. Furthermore, the study offers technological foresight into the short-and long-term prospects for financial services within the Metaverse. The final essay builds on previous essays by examining the Metaverse market as a promising ground for the evolution of Islamic finance. It studies the perspectives and challenges faced by Islamic finance in the Metaverse, exploring initial Islamic engagements in virtual realities. Furthermore, it formulates strategic frameworks for advancing Islamic financial institutions into the Metaverse, equipping them with necessary information and tactics.Collectively, these essays provide valuable empirical and theoretical insights, enhancing our understanding of financial markets and services in the Metaverse. This work advances scholarship in virtual finance and offers practical strategies for integrating Islamic finance into the digital realms of the Metaverse.

حفیظة بوخاري, مريم بلعربي

كلية العلوم الاجتماعية-جامعة عبد الحميد بن باديس مستغانم · الجزائر

حــمزة عــباس حــمزة عـــصـمـلي, Muataz Ali Atieh

كلية الهندسة-جامعة الملك فهد للبترول والمعادن · السعودية

This study was carried out to examine the power of carbon-based adsorbents include activated carbon, industrial fly ash, carbon nanotubes and carbon nanofibers in the removal of phenol and 4-chlorophenol (dangers of the human health) from the water. The system experiments conducted to obtain the ideal conditions to remove the highest ratio of phenol and 4-chlorophenol through the study of five variable elements, pH, the amount of dissolved material, contact time, mixing speed and the concentration of the dissolves pollutants in water. The affection of the impregnation metal oxides includes aluminum oxide, titanium oxide and iron oxide on the four carbon based adsorbent has been studied.The results indicated that among all four adsorbents, the highest removal of phenol was observed to be 95% by using 100 mg activated carbon impregnated with aluminum oxide per 100 ml of solution at pH 7 and agitation speed 200 rpm during a time of two hours. On the other hand, the highest removal of 4-chlorophenol was observed to be 93% by using 100 mg of activated carbon impregnated with aluminum oxide per 100 ml of solution at pH 6, 150 rpm speed of mixing and 2 hours of contact time. This high removal efficiency of activated carbon refers to its special surface pours structure and its good response to the modification to its surface by impregnated metal oxides.By applying the results of experiments, a mathematical equation representing the processes of adsorption and mechanical symmetric adsorption for each carbonic material from all used materials, in both states (raw and modified), have been developed. The adsorption capacities of phenol and 4-chlorophenol have been found on the surface of the four carbon adsorbents in both states (raw and modified) through these mathematical equations. The accuracy of the answers was completely identical with the conducted tests.