Digital Repository for University of Tripoli

The adomian decomposition method (ADM) was used to solve various wave equations. We compared the obtained solution by ADM with the Reduced Differential Transform Method (RDTM) and the Variational Iteration Method (VIM). The results show that ADM is very effective, simple and easy compared with other methods.
Muna Shaban Akrim(12-2019)

Building and infrastructure damages, such as tunnels, have become a more important issue because of the continuous expansion of rural and urban constructions. It is well-known that when high-strength concretes (HSCs) are exposed to high temperatures; it is more likely to experience explosive fire-induced spalling than conventional strength concrete. Spalling might result in catastrophic loss of life and damage to nearby critical infrastructure. The exposure of reinforcement bars to elevated temperature, decreased permeability, higher density, moisture transfer, and brittleness of the HSC contribute to spalling. The concrete on a structural member's surface may be violently ripped apart by a high and fast rising temperature during a fire. Despite being a non-combustible material, the physics-chemo-mechanical properties of concrete deteriorate when subject to high temperatures. The magnitude and duration of a fire in a concrete structure define the severity of the fire. The resistance to fire spalling of HSCs under different fire conditions, extremes, and tendencies must be explored urgently. Cementitious materials exhibited a positive impact as an alternative to cement in HSC because they are known as environmentally friendly concrete materials with superior fire-resistant properties. In addition, the inclusion of fibers as an additive reinforcement is adopted to prevent and mitigate fire spalling in HSCs. Therefore, the establishment of appropriate fire-safety measures is a fundamental requirement in building design to ensure the safety of its inhabitants. While the process of fire spalling for HSC during a fire has not yet been completely understood. For this reason, a critical literature study on recent developments in HSC fire-resistance performance should be conducted to determine the present fire spalling behavior of HSC in the event of high temperatures and/or a fire. This article systematically reviews the mechanisms, influential factors, and types of fire spalling. This literature also reviews the behavior, fire spalling modelling, and strategies to prevent spalling in HSC applications. Given the advantages of the research subject, several hotspot research topics for scientific investigations are also suggested to facilitate the widespread use of HSCs in advanced construction applications.
Hakim S. Abdelgader (5-2022)

Abstract Back ground: Full coverage porcelain fused to metal crowns (PFM) is commonly recommended for restoration of extensively damaged teeth. Ability of the dentist to adequately prepare teeth is necessary to achieve a proper success and longevity of these restoration. Aims: This study aimed to determine the degree of axial taper and total occlusal convergence angles (TOC) for Porcelain Fused To Metal crowns (PFM) prepared with clinically practiced values, that carried out by dental practitioners in Tripoli center, Libya. Materials and Methods: It was a descriptive, cross-sectional study design and held at Alzendah private dental laboratory, Tripoli Libya. A convenience sample (40) models of Porcelain Fused To Metal Crowns (PFM) preparations carried out by private dental practitioners were scanned by employing a 3D model scanner (Ceramill Map300, Amanngirrbach, Austria). Evaluation of the total occlusal convergence (TOC), bucco-lingual and mesio-distal convergence angles of each abutment tooth was proceeded using B&B dental software (Guide system, B&B, Italy). The degree of taper was measured on the axial walls of each crown preparation and the bucco-lingual and mesio-distal convergence angles subsequently calculated. Results: A total of 40 casts having crown preparations (15 anterior, 25 posterior). The mean convergence angles mesio-distally for all preparations was 40.29° (sd 21.8°), and for the bucco-lingual was 29.92° (sd 9.3°), with mean of TOC was 35.10°. In anterior preparations, the mean bucco-lingual convergence angle was 42.32° (sd 12.2°) compared to 24.52° (sd 15.5°) for posterior preparations (p
Dr. Khaled Omar & Abdussalam Eljabali(1-2022)

Abstract Introduction: Provisional restoration is an important part of fixed prosthodontics. It must provide pulp protection, positional stability, occlusion maintenance , and space preservation. There are two methods for provisional restoration fabrication; direct and indirect techniques. Aim: the study aims to identify the most preferred technique of fabricating provisional fixed restorations according to different parameters and situations and to highlight the advantages and disadvantages of each technique, by specialist dentists practicing in different dental clinics in Tripoli. Methodology: In this study, 120 closed ended questionnaires were distributed to specialist dentists in dental fixed restoration among different private dental clinics in Tripoli/Libya to find out which technique they prefer to apply in their clinics. Results: This study has revealed that dentists prefer the direct technique for the anterior area and single unit and up to 3-4 units fixed partial denture. While indirect technique was more commonly used by dentists in cases of multi-units and posterior teeth. In addition, it has a higher success rate and does not cause pulpal and gingival irritation.
NARJES ELGHEZAWI HANAN IRHOMA , ABDUSSALAM ELJABALI (7-2021)

بحث يُعنى بتأصيل السيرة الذاتية التي خلدها الشعراء في قصائدهم متجاوزين النثر، معتمدين على النص الشعري بما فيه من كثافة ووحدة وإشارات ، خصائص سيرة الشعر نوع فريد تشمله هذه الدراسة.
محمد الصادق سالم الخازمي(7-2017)

صدر عن حوليات الآداب والعلوم الاجتماعية التي تصدر عن مجلس النشر العلمي– جامعة الكويت سنة (2020) كتاب للأستاذ الدكتور منير كرادشة وآخرون بعنوان:" أوجه التحديات التي تواجه المسنين في سلطنة عمان: محافظة مسقط أنموذجا". وتم تقسيم محتويات الكتاب إلى خمسة فصول رئيسة، ويقع الكتاب في (123) صفحة، من الحجم المتوسط، والدكتور كرداشة هو أستاذ علم الاجتماع بجامعة اليرموك، ويعد من المختصين بالشأن العُماني، له عدة كتب ودراسات اجتماعية متخصصة عن سلطنة عُمان.
حسين سالم مرجين (5-2022)

one of the main factors that affect the success of the cast crown is the accuracy of the internal and marginal fit, a well-fitting crown reduces the chance for recurrent caries and periodontal disease, whereas the space between a poorly-fitting crown and tooth preparation enables accumulation of bacterial plaque, the use of paint- on die spacing technique to produce the cement gap and subsequently to improve the seating of the cast crowns has become quite popular in the recent years. The purpose of the study is to compare the marginal gap and the internal fit produced by two paint-on die spacing materials (Manicure and paint on die spacer ). Twenty four identical stone dies were made, 12 were coated with paint- on die spacer material, and 12 were coated with nail varnish material, the dies coated with die spacer were divided into three groups (DA,DB,DC), and the dies coated with nail varnish were also divided into three groups (VA,VB,VC), groups DA and VA were coated with one layer, DB and VB were coated with two layers, DC and VC were coated with three layers, for both groups wax patterns were made and casted using the lost waxing technique and all steps were standardized, impression replicas of the casted crowns were made and sectioned by means of the impression replica technique, measurements were taken using Scanning Electron Microscope, from 4 points (marginal gap, mid-axial, axio-occlusal and mid-occlusal). There was no statistical significant difference in accuracy between crowns fabricated on die spacer coated dies and crowns fabricated on nail varnish coated dies. with the crowns fabricated on die spacer coated dies being slightly more accurate.
ABDUSSALAM ELJABALI(12-2019)

Mobile terminals allow users to access services while on the move. This unique feature has driven the rapid growth in the mobile network industry, changing it from a new technology into a massive industry within less than two decades. In this thesis, we address admission control problems in a cellular wireless environment. The admission control is responsible for deciding whether an incoming call or connection can be accepted or not, which are based on the available codes . We provide an extensive survey of the existing admission control algorithms. The issues related to and the approaches for designing admission control in third generation(3G) cellular wireless networks are discussed. An admission control method considering the quality of service(QoS) requirements in wireless is presented along with an analytical traffic model for the Universal Mobile Telecommunication Systems(UMTS). In 3G networks we have dynamic capacity that depends on the interference levels in the covered area and the number of active users. This implies that the distance of a mobile user from the base station, which is called Node B, is also an important factor because of the signal fading. The first part of this work is an algorithm written in C++ programming language that distributes users in different zones assuming that the cell area is divided into Z virtual zones, where Z depends on the number of users. In the rest of this thesis we present a simulation model for the Universal Mobile Telecommunication Systems(UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of the mathematical model showed that, a product form equilibrium distribution holds in the case of two cells. Theses results are used to validate a simulation, and to show that the behaviour of the system is similar to that in the mathematical model. Once the product form of Jackson’s Theorem is known to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage of a network. To be more realistic, we used traffic distributions in the simulator, where a user can generate world wide web sessions(www), file transfer sessions, and Emails. These followed recommendations in the ETSI standard and further demonstrated the feasibility of the model.
Wael Saleh Abughres(7-2008)