المستودع الرقمي لـجامعة طرابلس

يواجه طلبة الدراسات العليا في الجامعات الليبية العديد من المشاكل والصعوبات التي تعوق دون اكمال مسيرتهم العلمية في الوقت المطلوب، ويعد دراسة هذه المشاكل والوقوف عليها وتقييمها من أهم الركائز لتطوير اي برنامج دراسات عليا مستقبلاً، ومن هنا قام الباحث بدراسة العوائق التي تحول دون اكمال الطالب لدراسته العليا في الوقت المحدد وذلك حسب ما تشير اليه المادة 126 من اللائحة 501 لسنة 2010 والتي تحدد مدة دراسة الماجستير بثلاثة سنوات، مع امكانية اضافة ستة أشهر كحالة استثنائية، حيث لاحظنا استغراق الطالب لوقت طويل جداً لإكمال دراسته العليا، وذلك من خلال تواجد الباحث بصفة عضو هيئة تدريس بقسم الإعلام. ومن هنا تلخصت مشكلة البحث في السؤال: " ماهي الأسباب التي تجعل من طالب الدراسات العليا يستغرق أربع سنوات او اكثر للحصول على درجة الماجستير؟"، وقد أستخدم الباحث المنهج الوصفي كمنهجية للبحث، وأستخدم والاستبيان والمقابلة للحصول على نتائج واقعية من خلال العينة التي تم دراستها، وهي دفعة خريف 2015 لطلبة الدراسات العليا بقسم الإعلام بجامعة طرابلس. وتركزت أهداف البحث في معرفة الاسباب التي تجعل من الطالب يأخذ وقت طويل لمناقشة رسالة الماجستير والتأكد من المرحلة التي وصل اليها الطالب في دراسته العليا، وكذلك مدى اتساق أسباب التأخر بين الطالب والأستاذ، ومن خلال نتائج الاستبيان والمقابلة توصل الباحث لأهم النتائج وهي أن الطلبة والأستاذ اتفقوا على أن الظروف الخارجة عن المألوف كالحروب وماصاحبها من تهجير وعواقب نفسية واجتماعية وأخيراً جائحة كورونا كانت من أهم الاسباب التي جعلت اكمال الماجستير يستغرق وقت طويل، ,توصل الباحث أيضاً بأن اعتماد العنوان والخطة لم يستغرق وقتاُ طويلاً ولكن المشكلة في مرحلة مابعد الخطة، وأيضاً غياب أساتذة متخصصين في العلاقات العامة حال دون وجود تناسق وانسجام مع طالب العلاقات مما ساهم في اطالة أمد الدراسة، ومن أهم الاسباب التي ركز عليها أساتذة الدراسات العليا هي عدم اتقان الطالب لمناهج البحث العلمي.
نجيب فرج رحومة(3-2021)

Background: Management of partially edentulous patients with hard and soft tissue undercuts is complicated, and the use of flexible dentures for these cases offers dual advantages of aesthetics and flexibility. However, research shows a varying preference for flexible dentures among general dental practitioners, prosthodontists, and other dental specialties. Objectives: The aim of this study was to survey the attitude and awareness of a sample of Libyan dental clinicians towards advantages, disadvantages, indications, and contraindications of flexible dentures. Material and methods: A descriptive cross-sectional study was conducted among 250 dentists currently practicing in different cities of Libya. Only 218 dentists responded. Using Google form software, a self-administrable e-questionnaire consisting of thirty-one multiple choice questions with "yes," "no" or "not sure" answers encompassing major aspects of flexible dentures was conducted through an online survey. Results: Out of 250 Libyan dentists to whom the questionnaire was sent, only 218 dentists responded and our results revealed that the respondents were females more than males with a ratio (2:1) and more than half of them were of age group (35-60 years) work in governmental dental practice with more than ten years of experience and 34.9% of them prefer and often offer flexible dentures to their patients. The majority of respondents with a long-term success of the flexible denture were prosthodontists who had more than ten years of experience with a correct response rate of more than 50% of questions that reflected their attitude and knowledge. Conclusions: Despite the fact that flexible dentures are not taught in Libyan universities of dentistry, about more than one-third of respondents prefer and recommend this treatment to their patients, and the long-term success of these prostheses was dependent on clinicians' education and their clinical experience.
Yusra Muftah Saad Elfaidy, Warida Abdalla Elnaihoum, Aseidah Abdullah Elgotrany(4-2022)

INTRODUCTION: CAD/CAM denture base materials are milled from pre-polymerized pucks of resin that are highly condensed. So, they provide no polymerization shrinkage eliminating its subsequent disadvantages. This technology offered improved fit, strength properties and more bio-hygienic denture bases compared with conventional processing of the denture base material. OBJECTIVES: The aim of the study was to evaluate the physico-mechanical properties of CAD/CAM denture base material and the effect of thermo-cycling on it compared with the conventional one. MATERIALS AND METHODS: The study was conducted on two parallel groups, divided according to the denture material used. Group (1) conventional PMMA (control group), group (II) CAD/CAM PMMA (study group) of 40 specimens each (16 for impact strength, 16 for flexural strength, 8 for surface roughness and grinded powder form both materials for residual monomer test). Each group was divided into 2 sub-groups: (A) No thermo-cycling and (B) Thermo-cycling, then subjected to 4 different tests, impact strength, flexural strength, surface roughness and residual monomer tests. Data were collected, tabulated and statistically analyzed. Significance level was set at 5%. Bar charts were used for graphical presentations. RESULTS: Our study revealed a highly statistically significant decrease in residual monomer of CAD/CAM PMMA material in both conditions before and after thermo-cycling when compared to conventional PMMA material, which therefore leads to enhanced impact strength and significantly reduced surface roughness after heat treatment. On the other hand, also a highly significant reduction of its flexural strength after thermocycling has been observed. CONCLUSIONS: CAD/CAM dentures with lower amount of methacrylate monomer exhibit more favourable physico-mechanical properties and they have a long-term biocompatibility even with thermal changes making them a more satisfactory as a denture base material for edentulous patients.
Yusra Muftah Saad Elfaidy, Ahmed M. Abdelhamid, Sonia M. Elshabrawy(12-2018)

For decades, lightweight concrete has been used in various civil engineering applications. Cellular concrete is a type of lighweight concrete that is an emerging composite in materials engineering still. However, due to its low weight, it can be integrated with industrial by-products to develop more advanced composites such as ultra-lightweight cellular concrete (ULCC). ULCC is sustainable and regarded as a potential candidate due to its simplicity of use and other benefits. A systematic review of the potential applications of ULCC in geotechnical construction are presented in this review article. Due to technological breakthroughs and changes in environmental conditions, and their material property is one of the variables that influence the degradation of roadway. Several investigations have been conducted by incorporating different materials into pavement structures to achieve longer-lasting and better pavement infrastructures than those at present. Sustainability benefits, workability, low prices, time, and structural capacity are factors that have been widely focused. This study focuses on the raw materials, production techniques, types, and properties of the ULCCs. The boundary densities of the ULCCs were considered from 400 to 1600 kg/m3. Structures all across the globe have benefited from the usage of cellular concrete in some form or another. However, much work in this field should be focused on, particularly in geotechnical applications. Geotechnical applications need specific attention to develop this kind of concrete with enhanced qualities. In order to address this need, this review paper has extensively focused on raw materials, manufacturing procedures, cellular concrete characteristics, types and uses of ULCC, particularly in geotechnical applications. Furthermore, several limitations and gaps in ULCC application in highway construction are highlighted, and recommendations on further improving its use and performance are provided.
Hakim S. Abdelgader(6-2022)

3D integral imaging is a true 3D imaging technology. It offers the simplest form that is capable of recording and replaying the true light field 3D scene in the form of a planar intensity distribution, by employing microlens array. There is a new world health crisis threatening the humanity with the spread of Covid-19 (Coronavirus Disease-2019). The Covid-19 belongs to a family of viruses that may cause various symptoms such as pneumonia, fever, breathing difficulty, and lung infection. Real images of Covid-19 patients confirmed by computed tomography CT were used to segment areas of increased attenuation in the lungs, all compatible with ground glass opacities and consolidations. This paper describes a new method to generate an indicative Covid-19 3D integral image models. The method is based on a Multiprocessor Ray Tracing System including Philips viewer, 3D slicer software and unidirectional camera. Experimental results are extremely satisfactory and for the first time it is proved that 3D integral images Covid-19 models are generated through Multiprocessor ray tracing system in order to deep monitoring and visualization to could be aid diagnosis in the absence of RT-PCR kits as demonstrated. A new file format content is created as well.
Dr. Mahmoud Geat Eljadid(3-2022)

Bokashi is an organic fertilizer made from organic materials through fermentation process. A high quality bokashi should have C/N ratio between 10-20, which normally produced from a mix raw organic material with has C/N ratio of 30. However, many studies have shown a composition of raw organic material without a calculation of C/N ratio. Therefore, the objectives of this study were to gather the initial C/N ratio of various raw material from previous published studies, calculate the C/N ratio, and examine the descriptive characteristic (colour, aroma, and texture) of bokashi made from three selected C/N ratios of raw material (30, 70, and 110) and various length of fermentation (10, 17, and 24 days). This research combined literature reviews and laboratory experimental. For laboratory experimental, Complete Randomise Design (CRD) was applied. The result showed that all bokashi produced from raw material mixture with the C/N ratio up to 110 was still acceptable to be directly applied as a fertilizer. Bokashi produced with longer fermentation time had better texture but lower aroma and colour quality
RABYA A LAHMER(1-2021)

Decreased wheat crop yields due to the presence of weeds, insufficiently effective herbicides, and the development of weed resistance to high-efficiency herbicides indicated the need to develop alternative ways to control weeds. Therefore, we sought a possible solution in examining the efficiency of different concentrations (1, 5, 10 and 20%) of aqueous extracts of Ambrosia artemisiifolia and Sorghum halepense in controlling certain weed species for wheat crops: Avena fatua, Bromus rigidus and Convolvulus arvensis. The efficacy of aqueous extracts through the content of total phenols and four polyphenolic acids (chlorogenic, p-coumaric, and sikimic) on the level of shikimic acid concentration in treated weeds was investigated. Statistical analysis of the data showed that the change all tested concentrations of aqueous extracts affect the change in the concentrations of sikimic acid , especially the 20% solution of A. artemisiifolia. Conducted research also showed that method of monitoring the content of shikimic acid is adequate for determining the herbicidal effect of plant aqueous extracts
Rabya A Ibrahim(1-2022)

الملخص أظهرت النتائج الشهرية باستخدام أقماع بيرليزي وجود اختلافات في الكثافة العددية للحيوانات الدقيقة المرتبطة بأشجار الأيوكالبتوس أو الكافور Eucalyptus camaldulensis والصنوبر Pinus halepensis والعوامل المناخية في غابة النصر بطرابلس لإجمالي 021 عينة من نثار الأوراق لسنة 2112 . بلغ إجمالي الكثافة العددية للحيوانات الدقيقة السنوية 002.111 فردًا / 01 cm / m من نثار الأوراق. أوضحت النتائج أن الكثافة العددية للكوليمبولا كان فعالاً في تفكك ³ وتكسير نثار الأوراق، والحلم كمفترسات، والفطريات والبكتيريا لتحلل نثار الأوراق. تم تقسيم الدراسة إلى فترتين. ) 0( مايو - 2، والكوليمبولا 2.، والحيوانات الدقيقة الأخرى 011 فرد/ .. أكتوبر، أظهرت أن متوسط وفرة الحلم كان 2 01 cm / m ³ من نثار الأوراق على التوالي. ) 2( نوفمبر- أبريل، أظهرت أن متوسط وفرة الحلم كان 21 ، والكوليمبولا 135 ، ومجموعة الحيوانات الدقيقة الأخرى 011 فرداً / 15 cm / m نثار الأوراق على التوالي. أوضحت الدراسة وجود فروق ذات دلالة ³ معنوية عند المستوى 1.110 وفي اختبار Duncan عند المستوى 1.110 بين شهر يناير والأشهر الأخرى. تم عرض جميع البيانات البيولوجية والكيميائية والفيزيائية المؤثرة على التنوع البيولوجي لمفصليات الأرجل ونثار أوراق الكافور والصنوبر في غابة النصر بطرابلس. توصي الدراسة بالنظر في أهمية تعريف وتصنيف والتنوع البيولوجي للحيوانات الدقيقة والعوامل المختلفة المرتبطة بنثار الأوراق كمؤشرات بيئية مهمة واستدامة النظام البيئي للغابات في ليبيا.
هدي مصطفي عمر الشبة , نوال عبد السلام محفوظ(12-2021)