https://repository.sustech.edu/handle/123456789/28467 Tue, 18 Aug 2026 19:11:45 GMT 2026-08-18T19:11:45Z https://repository.sustech.edu/handle/123456789/28487 Geophysical Characterization of Waterlogging Phenomenon at Merowe – Sudan Osman, Khalid Abdelfattah M.; . Babiker, Elgaily M; Elmamoun, Mohamed E. Merowe town and the surrounding irrigated agricultural scheme have been affected by a severe waterlogging phenomenon, which has led to the collapse of numerous residential structures. This study aims to investigate the causes of groundwater table rise to near-surface levels and to propose appropriate mitigation measures. A geoelectrical investigation using the Vertical Electrical Sounding (VES) method was conducted and integrated with hydrogeological assessments and an evaluation of irrigation practices in the study area. The geology of the area is dominated by the Nubian Sandstone Formation, which is overlain by Quaternary to Recent sediments including Nile silt, alluvial deposits, and aeolian (wind-blown) sediments. Geophysical investigations indicate that the principal aquifer system comprises alluvial deposits consisting predominantly of sand, silt, and gravel, with a thickness generally of less than 10 m and resistivity values ranging from 300 to 1000 Ω•m. Underlain by pebbly sandstone and coarse- to medium-grained sandstone units, with thicknesses ranging from 20 to 50 m and resistivity values between 80 and 300 Ω•m. These sandstone units are intermittently interbedded with mudstone layers exhibiting resistivity values of less than 20 Ω•m. The Sum of Excess Water index revealed that the northern part of the study is very poorly drained. Surface water accumulation resulting from excessive irrigation is enhanced by the prevailing geological structure, which restricts effective subsurface drainage and consequently leads to a rise in the groundwater table. To mitigate these conditions, the study recommends improving irrigation management within the agricultural scheme. Integrated irrigation management, combining controlled surface canal irrigation with groundwater abstraction, is suggested as an effective strategy. Mon, 01 Jun 2026 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28487 2026-06-01T00:00:00Z https://repository.sustech.edu/handle/123456789/28485 Classical Vector Space-based Semantic Representation and Dimensionality Reduction for Arabic Text Clustering: a survey Nooreldeen, Ebtihal; Zanaboni, Anna Maria The Arabic language poses many challenges for automatic text processing due to its linguistic complexity, including rich morphology, the use of diacritics, and the frequent omission of vowels in written text. In general, two key factors significantly influence performance in text processing: the incorporation of semantic information in document representation and the control of dimensionality. This paper presents a survey of Arabic document clustering employing classical vector space models for text representation (as opposed to dense embedding models), with a particular focus on semantic representation and dimensionality reduction. The survey explores several applications of clustering, such as text summarization and information extraction, and reviews existing comparisons between clustering algorithms. Although classical vector space methods provide a somewhat limited perspective, the body of work found, covering the period from 2001 to 2025, is quite diverse. Key challenges, major findings, and the Arabic document corpora used in the reviewed literature are concisely presented in comprehensive synoptic tables Tue, 03 Feb 2026 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28485 2026-02-03T00:00:00Z https://repository.sustech.edu/handle/123456789/28475 The Stability Analysis of a Modified Cascade Control Strategy for Khartoum Refinery Delayed Coking Unit's Drums Ahmed, Lina Amer Alsharif; Hamed, Tomadir Awad Ibraheem The delayed coking unit is a process that converts heavy oil residues into more valuable products. The pressure control of the coking drums is important for process safety, yield, and stability. However, it has received limited study compared to temperature control. Cascade control is suitable for many industrial processes, especially when enhanced by combining proportional (P), integral (I), and derivative (D) actions in the control loops. This study focused on modifying a previous cascade control strategy developed to control the pressure inside the coking drums at Khartoum Refinery by controlling the heating fuel flow rate. The modification included replacing the Proportional (P) controller in the secondary loop with Proportional-Integral (PI) and Proportional-Integral-Derivative (PID) controllers to evaluate their impact on the overall control system stability. MATLAB simulations were used to calculate system transfer functions and test stability through direct substitution, root locus, Bode plots, and step response analysis. The results showed instability with both controllers due to reduced phase margins and increased high-frequency noise. Several control strategies were recommended to enhance the system performance, such as Lead/Lag compensators, Model Predictive Control (MPC), and State Feedback control. Sat, 23 May 2026 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28475 2026-05-23T00:00:00Z https://repository.sustech.edu/handle/123456789/28474 التصور القرآني للبناء والعمران: قراءة هندسية آدم, فتح الرحمن محمد; حبيب, الطيب عبد اللطيف تُعنى الهندسة المدنية بتطوير البنية التحتية، بما في ذلك المباني والطرق وشبكات المياه والصرف الصحي، بما يسهم في خدمة المجتمعات البشرية. وعلى مر العصور، أسهم الباحثون في إرساء القواعد العلمية والمعرفية لهذا المجال. يهدف هذا البحث إلى استكشاف أوجه التقاطع المعرفي بين مفاهيم الهندسة المدنية والدلالات المتعلقة بالبناء والعمران الواردة في القرآن الكريم.، بهدف تأصيل المعرفة الهندسية وربطها بالوحي. ولتحقيق ذلك، اعتمدت الدراسة منهجاً تحليلياً لاستخراج الآيات القرآنية المتعلقة بالتشييد وتفسيرها باستخدام برنامج "الباحث القرآني" وأدوات الذكاء الاصطناعي. ركزت الدراسة على تحليل المكونات الإنشائية الأساسية، كالقواعد (الأساسات)، الأعمدة، والأسقف، بالإضافة إلى تقييم مواد البناء المذكورة في النص القرآني. وتوصلت النتائج إلى وجود توافق دقيق بين الإشارات القرآنية والمبادئ الحديثة للهندسة المدنية، مما يعكس إعجازاً علمياً مبكراً في هذا المجال. وتوصي الدراسة ب ضرورة توظيف هذا التأصيل المعرفي لتطوير حلول هندسية مستدامة ومبتكرة لمواجهة التحديات العمرانية المعاصرة. Sat, 23 May 2026 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28474 2026-05-23T00:00:00Z