Center for Solar Energy Research and Studies

Remediating petroleum-contaminated soils from oil fields is one of the most challenging tasks for both the Libyan oil sector and the global oil industry. It is therefore necessary to isolate and identify bacteria capable of metabolically synthesising biosurfactants from oil-contaminated soil, as they can be used for bioremediation. Two bacterial strains, which degrade petroleum hydrocarbons and produce biosurfactants, were isolated from oil-contaminated soils in the southern Sirte basin in central North Libya, using an enrichment technique. Morphological, biochemical, and 16S rRNA analyses indicated that the isolates are more likely to be of the species Dietzia cinnamea and Rhodococcus pyridinivorans. The biodegradation efficiency (BE) of crude oil and diesel oil separately (1% v/v) was evaluated after 14days of incubation for both strains using the GC-FID technique. The strains effectively degraded 91.87% and 75.35% of the crude oil. Whereas for diesel oil, they displayed a lower BE of 87.61% and 70.14%, respectively. Multiple screening tests were then used to check for the production of bioemulsifiers in the bacterial isolates. The drop collapse test was positive for both bacteria tested, collapsing the culture supernatant in less than 30s. The oil spread test performed with crude oil showed a clear zone of 2.98 ± 0.02cm and 2.71 ± 0.04cm in diameter, respectively. Furthermore, the emulsification index (E24) of biosurfactant against diesel oil was measured to be 34 ± 0.17% and 30.8 ± 0.3%, respectively. It was found that biosurfactants can enhance the efficiency of oil degradation, which makes them attractive for future application in the MEOR (microbial enhanced oil recovery) process. Therefore, it has potential applications in bioremediation.

تستكشف هذه الدراسة حلاً مستداماً لمعالجة عدم التطابق الومني بين العرض والطلب على الكهرباء في منطقة براك الشاطئ من خلال استغلال فائض الكهرباء خلال ساعات انخفاض الطلب لإنتاج الهيدروجين عبر التحليل الكهربائي، ثم استخدام خلايا الوقود لتوليد الكهرباء خلال فترات الذروة. تقيم الدراسة جدوى استخدام نظام يعتمد على الهيدروجين لتحقيق استقرار الشبكة الفرعية دون الحاجة إلى وحدات توليد كهرباء إضافية. ووفقاً للنتائج، يمكن للمحلل الكهربائي إنتاج ما يصل إلى 271.8 متر مكعب من الهيدروجين في الساعة، ويتطلب ذلك حوالي 9.1 ميغاواط من الكهرباء، وهو ما يكفي لتغطية العجز في الطاقة البالغ 6.1 ميغاواط في الشبكة. وبسعة تخزين للهيدروجين تبلغ 421,255 متر مكعب، يمكن لهذا النظام تخزين الهيدروجين لاستخدامه لاحقاً في خلايا الوقود لتغطية العجز البالغ 1689 ميغاواط في الشبكة الفرعية خلال أوقات الذروة. وتشير النتائج إلى أنه من خلال تحسين إنتاج الهيدروجين بالتحليل الكهربائي واستخدام خلايا الوقود لتوليد الكهرباء، يمكن للنظام المقترح توفير 8,424 ميغاواط من الطاقة، مما يغطي فعلياً عجز الشبكة. ولا يقتصر هذا الأسلوب على سد الفجوة بين العرض والطلب فحسب، بل يثبت أيضاً أنه حل فعال من حيث التكلفة والكفاءة لتحقيق استقرار الشبكة دون الحاجة إلى محطات توليد كهرباء إضافية.

تقدم هذه الورقة تحليلاً لنظام طاقة شمسية عائم بقدرة 600 ميجاوات مقترح تركيبه في الخمس، ليبيا. تمت محاكاة النظام باستخدام برنامج PVsyst الإصدار 7.4 مع طريقة التحويل القائمة على طريقة HDKR باستخدام بيانات الطقس من Meteonorm الإصدار 8.1 ومصادر بيانات الطقس Solargis. تظهر نتائج المحاكاة أن النظام سيحقق إنتاجًا سنويًا للطاقة يبلغ 1,346 جيجاوات ساعة/سنة، ونسبة أداء للنظام تبلغ 81.7٪، وإنتاجًا محددًا للطاقة يتراوح بين 1,850 و 2,050 كيلووات ساعة/كيلوواط/سنة مع عامل قدرة يبلغ 25.6٪. سيحقق نظام FPV مكاسب إشعاع خلفي ثنائي الوجه تتراوح بين 3.0 و4.5٪ وسيوفر 1.25 مليون متر مكعب من المياه السطحية سنويًا، ما يعادل قيمة نقدية تتراوح بين 250,000 و625,000 يورو سنويًا. يبلغ إجمالي الاستثمار المطلوب للمشروع ما بين 480 و540 مليون يورو، أي ما يعادل 0.80 إلى 0.90 يورو لكل واط ذروة من التيار المباشر، وينتج عنه تكلفة طاقة متوسطة (LCOE) تتراوح بين 0.055 و 0.065 يورو لكل كيلوواط/ساعة على مدى 25 عامًا ومعدل خصم 5٪. وهذا يتماشى مع LCOE لمحطات الطاقة التقليدية في ليبيا، والتي تتراوح بين 0.07 و 0.10 يورو لكل كيلوواط/ساعة. عند إضافة التكلفة الكربون (SC_CO2 ~70 دولارًا أمريكيًا/طن CO2)، تتراوح تكلفة الطاقة المعدلة بيئيًا بين 0.028 و0.035 يورو/كيلوواط ساعة. تثبت النتائج التي تم الحصول عليها جدوى أنظمة الطاقة الكهروضوئية العائمة (FPV) على نطاق المرافق العامة في ليبيا.

Helicobacter pylori (H. pylori) infection remains a major health problem in developing countries because of its high prevalence. H. pylori colonizes the stomach of children and causes local inflammation. Accurate diagnosis is essential to ensure appropriate treatment and reduce the risk of long-term complications. In Libya, limited data are available regarding H. pylori diagnostic methods. The Objective of this study was to compare the diagnostic performance of invasive and non-invasive methods for detecting H. pylori infection among pediatric dyspeptic patients (histopathology method and serology method). A gastric biopsy and a blood sample were collected from 120 dyspeptic children attending the gastroenterology units at Tripoli Children's Hospital. The overall prevalence of H. pylori infection was 84% using the invasive method, and 51% using the non-invasive method. The histopathology-based diagnostic method is the gold standard diagnostic tool for H. pylori detection. However, additional research with a higher number of patients and in other areas of Libya should be conducted in the future to confirm the study's findings.

Recruitment systems face increasing challenges due to the diversity of résumé formats, lack of personalized guidance for job seekers, and the persistence of human bias in candidate evaluation. Traditional systems often fail to accurately extract essential information, assess résumé quality, and provide actionable recommendations aligned with labor market requirements. This paper presents an intelligent résumé analysis and job recommendation system based on Natural Language Processing (NLP) and transparent rule-based logic. The system extracts structured information from text-based PDF résumés using PDFMiner3, PyResParser, and spaCy. Résumé quality is evaluated using a rule-based scoring mechanism, while skill gap analysis is performed through explicit comparison between extracted skills and predefined domain requirements. Based on this analysis, the system generates personalized job and training recommendations. The system was evaluated through laboratory testing and real-world field evaluation in collaboration with Human Resources specialists. Experimental results show 90% skill extraction accuracy, 92% job domain classification accuracy, 89% skill gap detection accuracy, and over 91% relevance in job and training recommendations. The findings demonstrate that the proposed system provides an effective, interpretable, and fair solution for intelligent recruitment and career development

The long-term reliability of Linear Fresnel Reflector (LFR) systems is critically limited by thermomechanical stress, which arises from heterogeneous solar flux on the receiver tube. To address this challenge, this work investigates the optical performance of two new Concave-Wall Design, of 45° and 90° orientations, evacuated receivers. A comparative analysis against a conventional circular absorber was conducted using high-fidelity Monte Carlo ray-tracing across diverse geographic and seasonal conditions. The primary finding is that the Concave-Wall Design of 90° orientation geometry provides a substantial enhancement in thermal management; heat flux non-uniformity was reduced by up to 15 %, a result achieved by geometrically dividing the concentrated flux to eliminate damaging hotspots. While optically competitive, the Concave-Wall Design designs also showed a minor efficiency gain (2–4 %) at low solar angles. This study demonstrates that a strategic geometric redesign can solve a key failure mode in linear Fresnel reflector technology, showing that a negligible trade-off in peak optical performance yields a crucial improvement in thermal stability and receiver durability.

With a growing demand for electric power, interconnecting national grids is crucial for ensuring stability and creating economic benefits through energy export1. This paper evaluates the transmission lines of the Libyan Electrical Network to determine their capacity to accommodate additional power for export the electrical energy to the Southern Europe Countries. The study simulates the injection of power from new photovoltaic (PV) stations in Ghadames, Asdaada, Hoon, and Bani Walid, and then analyses the grid's stability when this power is withdrawn from two potential coastal interconnection points, Al Garaboly and Al-Khoms. Using NEPLAN software, network performance was assessed under normal (N) and contingency (N-1) conditions across three scenarios, which are: the existing Libyan grid scenario, and changing the existing ratio of Current Transformer (CT) scenario, the final scenario is integration of new 400 kV lines currently under construction. The results indicate that Al-Khoms is a more robust interconnection land point than Al-Garabuli. The most effective strategy for increasing export capacity involves activating the new 400 kV lines, which allowed for a maximum stable export of 1430 MW from Al-Khoms Station and 660 MW from Al- Garaboly Station under N-1 conditions. The evaluation of the transmission network is a fundamental aspect in selecting the optimal connection land point. However, several other considerations influence the final decision regarding the connection, such as the route of the submarine cable. These considerations include environmental studies that account for sensitive areas such as coral reefs and ecological impacts, in addition to oil concessions and military sites etc. It is essential to consider these factors to determine the best electrical connection point.

Fracture toughness is a critical mechanical property influencing the clinical durability of prosthodontic materials, especially those used in high-stress posterior regions. Differences in composition, microstructure, and fabrication technologies can significantly affect resistance to crack propagation. This experimental study evaluated the fracture toughness of three prosthodontic material groups (n = 10 each). Standardized samples were prepared and tested using the Vickers indentation technique under controlled laboratory conditions. Descriptive statistics were calculated for each group, and a one-way analysis of variance (ANOVA) was performed to determine significant differences among the groups. Post-hoc pairwise comparisons were conducted using Tukey’s Honest Significant Difference (HSD) test. Statistically significant differences in fracture toughness were observed among the three groups (p < 0.001). Group II demonstrated the highest mean fracture toughness (5.39 ± 0.34 MPa·m^1/2), followed by Group III (4.34 ± 0.36 MPa·m1/2). Group I recorded the lowest mean value (2.82 ± 0.56 MPa·m1/2). Tukey’s post-hoc analysis confirmed that all pairwise comparisons were significant (p < 0.001), indicating that each material group exhibited distinct mechanical performance profiles. The findings show that the fracture toughness of prosthodontic materials vary significantly depending on their composition and manufacturing technology. Materials in Group II outperformed the other groups, suggesting greater suitability for clinical situations where high resistance to fracture is required. Further studies incorporating additional mechanical tests and long-term clinical evaluation are recommended to validate these results under functional oral conditions.

This study investigates the physicochemical interactions between cocarboxylase (a hydrophilic derivative of thiamin) and three anionic surfactants, sodium cholate (NaC), sodium deoxy cholate (NaDC), and sodium dodecyl sulfate (SDS), in aqueous media. A multi-technique approach comprising UV–Vis spectroscopy, conductivity, surface tension, and viscosity measurements was employed to examine micellization, interfacial properties, and encapsulation efficiency. The critical micelle concentration (CMC) of NaC, NaDC, and SDS decreased in the presence of cocarboxylase. The values of binding constant indicate to stronger interaction between cocarboxylase and NaDC micelles as against NaC and SDS micelles. Thermodynamic parameters indicate that the micellization and drug-micelle interaction are spontaneous processes. Morphological analysis confirmed spherical micelle formation across all systems. Overall, the finding emphasize the potential of the bile salt micelles, especially NaDC, as effective carriers for the encapsulation and delivery of hydrophilic molecules such as cocarboxylase.