http://dspace.zu.edu.ly/xmlui/handle/1/1748 Wed, 08 Apr 2026 21:44:25 GMT 2026-04-08T21:44:25Z https://dspace.zu.edu.ly:443/bitstream/id/9a9ef79d-cc3f-4e48-9c75-9eeb97a72904/ http://dspace.zu.edu.ly/xmlui/handle/1/1748 http://dspace.zu.edu.ly/xmlui/handle/1/1870 Stability and Control of Non-Linear Dynamical System Subjected to Multi External Force with Velocity Feedback Soleman, Samira M.; Shiabani, Hanan M.; Sewaee, Fatma M. Abstract: The response of a dynamical non-linear system of two-degree-of freedom, subjected to multi excitations forces is investigated. Analysis of the amplitude and phase plane are obtained. The multiple scale analyses of various 1:2 internal resonance conditions and simultaneous resonance case are considered. The method of multiple time scale (MTS) is applied to solve the non-linear differential equations describing the system up to second order approximation. All possible resonance cases at this approximation are obtained and studied numerically to determine the worst case. The effects of different parameters are studied. The frequency response equations are solved numerically. These vibrations were controlled using the damper . الملخص: تم التحقيق في استجابة نظام ديناميكي غير خطي من الدرجة الثانية والذي يتعرض لقوى خارجية متعددة. يتم الحصول على السعة تحليليا. وقد تم دراسة التحليلات متعددة النطاق لمختلف شروط الرنين الداخلي والرنين المختلط بنسبة .1:2 يتم تطبيق طريقة المقياس (MTS) لحل المعادلات التفاضلية غير الخطية التي تصف النظام حتى التقريب من الدرجة الثانية. يتم الحصول على جميع حالات الرنين الممكنة عند هذا التقريب ودراستها عدديا لتحديد الحالة الاسوأ. تمت دراسة تأثيرات المعاملات المختلفة. تحل معادلات استجابة التردد عدديا. تم التحكم في الاهتزازات باستخدام المخمد . Tue, 15 Feb 2022 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/1870 2022-02-15T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/1777 غلاف كتاب المؤتمر + فهرس المحتويات التقنية, اللجنة Tue, 15 Feb 2022 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/1777 2022-02-15T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/1776 PREDICTION OF CALCIUM CARBONATE AND CALCUIM SULFATE SCALE DEPOSITS IN MABRUK OIL FIELD, LIBYA Alnajar, Asmaa D.; Refai, R. T. This Study focuses on predictions and probability of calcium carbonate and calcium sulfate scale formation. It has been conducted in the Sirt Basin on concession ‘‘NC -17’’ namely is Mabruke oil – field. Twenty-six chemically analysed water samples from different wells in this oil field were used in this study; these samples showed Total Dissolved Solids (TDS) ranges from 9075 to 85261 mg/L. The chemical analysis of petroleum – associated waters from such wells was studied and interpreted. This was done in order to find out and predict CaCO3 and CaSO4 scales. This prediction was based on geochemical analytical calculations as well as applying Stiff and Davis method, this method is one of the easiest ways to calculate calcium carbonate and calcium sulfate scaling in brines, Where the saturation index is calculated and thus the prediction of scaling deposits. Accordingly, it was found that CaCO3 scale was found to be likely in most water samples, Factors causing this type of scale are mainly pH, Pressure, HCO3 and Ca concentrations. On the contrary CaSO4 scale was found unlikely in most of the studied waters, with the fact that salinity, Ca+2 and SO4-2 concentrations are the main factors causing such scale. Tue, 15 Feb 2022 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/1776 2022-02-15T00:00:00Z http://dspace.zu.edu.ly/xmlui/handle/1/1775 ON NEUTROSOPHIC PRE-APPROXIMATION SPACE Al Amin, Entesar The purpose of this article is to extend some more topics of topology in neutrosophic topology. We introduce the concept of neutrosophic pre-approximation space and its properties. Pre-open (pre-closed) sets are investigated. In addition, we define pre- lower (pre- upper) approximations of neutrosophic sets ; we define a new type of sets called neutrosophic pre- rough (pre-exact) sets and investigate some of their properties. We will develop five well-defined new regions and study the relationship between them, which will be useful in the study of GIS. Tue, 15 Feb 2022 00:00:00 GMT http://dspace.zu.edu.ly/xmlui/handle/1/1775 2022-02-15T00:00:00Z