الملخص

يواجه استقرار الجهد تحديات كبيرة بسبب الطلب المتزايد على الكهرباء والاعتماد على خطوط النقل الطويلة، خاصة في شبكات الجهد المتوسط بجنوب ليبيا. تركز هذه الدراسة على شبكة سبها بجهد 66 كيلو فولت، التي تعاني من عدم استقرار الجهد نتيجة الاعتماد على مصادر توليد الطاقة الشمالية وخسائر الطاقة التفاعلية العالية. باستخدام برنامج، NEPLAN تم تقييم فعالية جهازين من تقنيات، FACTS وهما المعوض المتزامن الثابت (SVC) والمعوض المتزامن الديناميكي، (STATCOM) في تحسين استقرار الجهد.

تناولت الدراسة ثلاثة سيناريوهات: بدون تعويض، باستخدام، SVC وباستخدام. STATCOM أظهرت النتائج أن كلا الجهازين يحسنان استقرار الجهد بشكل ملحوظ ويقللان من خسائر الطاقة، مع تفوق STATCOM في الاستجابة الديناميكية والكفاءة الإجمالية. تؤكد هذه النتائج أهمية تقنيات التعويض المتقدمة في ضمان استقرار وموثوقية توصيل الطاقة في الظروف التشغيلية الصعبة.

Abstract The aim of this study was to estimate the levels of TNF-α in serum and gingival crevicular fluid, in patients with chronic periodontitis (CP), before and after phase I therapy with subgingival delivery of Hyaluronic acid (Gengigel Gel). A total of thirty subjects were included in this study; 20 CP patients as a study group (group I) and 10 systemically healthy subjects with clinically healthy gingiva as a control group (group II). The nonsurgical periodontal therapy (SRP) + HA gel were done in group I. Periodontal parameters, including PI, GI, BOP, PD and the CAL, were recorded. GCF and serum were collected from all individuals included in the study; the first sample was collected from all groups (study and control) before treatment. The second sample was collected 4 weeks after subgingival delivery of Hyaluronic acid & phase I therapy from group I. Levels of TNF-α in GCF and serum were quantified using ELISA. The results showed a statistically significant reduction in total levels of TNF-α in serum and TNF-α in GCF in study group after application of Hyaluronic acid with phase I therapy. Results also showed all clinical parameters were significantly improved after application of Hyaluronic acid with phase I therapy in groups I (p<0.001). Scaling and root planing (SRP) is the mainstay of treatment of periodontal diseases, furthermore subgingival application of Hyaluronic acid gel with SRP were effective in improving clinical parameters in CP patients. TNF-α level in serum and GCF are reduced after phase I therapy with application of Hyaluronic acid.

Abstract

As technological advancements continue to revolutionize teaching, the use of technology in both college/university and classrooms is making flipped learning a trending instructional model. The roles and responsibilities of instructors and students often require a new or enhanced skill set where the instructor designs intentional learning experiences to engage students outside of the classroom. This research was conducted to investigate the effectiveness of flipped learning strategy to overcome the educational communication problems. Also, it has been explained the definition of the flipped classroom and its impact on course evaluations and student outcomes. Besides, it has been discussed the comparison between the flipped learning strategy and the traditional way of teaching. As well, it has been explained some advantages and disadvantages of the flipped classroom. Above and beyond, it has been mentioned the most important critiques against the flipped leaning. More to the point, it has been shown some steps to implement the flipped classroom strategy. As well as, it has been presented some reasons of why should be flipped our classrooms. Ultimately, some important recommendations have been given to guarantee an effective learning in the education process.

Key words:  flipped classrooms, flipped learning, higher education, technological advancement, effective flipping ,

This study investigates whether internal auditors in Libyan oil companies possess the necessary competence and capabilities in the security of electronic accounting information systems within an era of transition from manual auditing to electronic accounting information system auditing. The study also examines the issue of whether internal auditors implement sufficient safeguards to address the risks associated with electronic accounting information systems. A questionnaire survey adopted for data collection revealed that: internal auditors in the sampled companies possess a high level of competence and efficiency in electronic accounting information system security; and that they also follow all protective measures to counter the risks of electronic accounting information systems. However, descriptive statistics show that the mean scores of participants' responses regarding the competence and efficiency of internal auditors in electronic accounting information system security were lower than the overall mean of the axis. This could be seen as a deficiency on the part of internal auditors in reviewing risks related to electronic accounting information systems, monitoring management's implementation of regular maintenance of electronic systems, ensuring the existence of sufficient protection programs to scan electronic programs or magnetic disks, implementing procedures to limit risks arising from electronic equipment damage, and periodically evaluating information security applications within the company. Descriptive statistics also indicate that the average scores of participants' responses regarding internal auditors' adherence to all protective measures to counter the risks of electronic accounting information systems were lower than the overall mean of the axis. This could be seen as a deficiency on the part of internal auditors in monitoring IT staff in implementing required security measures, participating in updating security methods according to changes in the evolving IT environment, participating in developing specific security policies such as selecting the appropriate technology and its effectiveness, participating in developing and formulating a strategy for developing the security of electronic accounting information systems, and contributing to the detection of security breaches through reports and describing the type of breach

Vortex airflow-assisted melt differential electrospinning for preparing superfine fiber yarns was proposed. This method with solvent-free exhibits a higher yield of 20 ± 5.17 m/min compared to the range of 0–5 m/min achieved by solution electrospinning with organic solvents. Simulation and high-speed photography show that the fibers are aggregated by suction airflow and twisted into yarns by vortex airflow. Polylactic acid (PLA) superfine fiber yarns exhibit fine fiber diameters ranging from 0.96 to 5.57 μm, a yarn diameter of 211.7 ± 40.8 μm, and a high tensile strength of 39.4 ± 3.12 MPa. Furthermore, these PLA melt electrospun yarns can be woven into fabric with a water contact angle of 120.1° and triboelectric voltage of 7.41 V, demonstrating their potential in self-cleaning textiles and flexible smart textiles. Moreover, this method is generally applicable to thermoplastic polymers including polyethylene …