Mitigating Resonant Vibration via Compressor Base Frame redesign at Souq Al-Khamis Cement Factory, Libya (Part II)
Journal Article

Resonance occurs when the operating frequency of a system aligns with its natural frequency, resulting in amplified vibration amplitudes. To prevent potential damage and ensure optimal performance of a compressor's base frame at Souq Al-Khamis Cement Factory, researchers found the resonance in has been occurred when both the natural frequencies and rotating frequency were overlapped. Resonant Vibration in the base frames arises when the rotating vibration frequency aligns with the frame’s natural modes that leads to structural instability, fault unplanned shutdowns and production losses. This study analyzes resonant vibration in a cement factory compressor base frame and proposes a redesign using finite element methods to mitigate this issue. Four distinct modifications were made to the base frame on its shape, weight and boundary conditions: the first introduces fixed points to enhance rigidity, the second adds supports for increased stability, the third incorporates elements to improve durability, and the fourth enhances the thickness of the compressor. The results indicate that the redesigned configuration most effectively mitigates resonance and improves the system's natural frequency response.

Osama Amhammeed Altaher Hassin, Mostafa H Essuri Abobaker, (05-2025), Academy journal for Basic and Applied Sciences (AJBAS): الأكاديمية الليبية, 7 (1), 1-5

Comprehensive Analytical Study of Structural Reclamation in Aging Flexible Pavement
Journal Article

The progressive deterioration of flexible pavements, driven by increasing traffic loads, environmental influences, and material aging, necessitates the implementation of effective structural reclamation strategies to restore functional performance and extend service life. This study focuses on a critical segment of the Libyan coastal road network, specifically the 27.5 km part from Tripoli Street Bridge to Al-Krarim Gate. An analytical and quantitative investigation is undertaken to evaluate the structural condition and rehabilitation potential of the existing flexible pavement system, with particular attention to distress mechanisms, material degradation, and the effectiveness of various rehabilitation techniques. The assessment integrates field investigations, laboratory testing, based on AASHTO 1993, and to evaluate pavement distress, base soil strength, and asphalt concrete layers performance; Pavement Condition Index (PCI) values and core sample analyses are employed to determine the extent of structural failure. Visual distress surveys supplement the data to provide a comprehensive understanding of surface and sub-surface conditions. Analytical modeling, based on layered elastic theory is used to simulate pavement response under rehabilitated conditions and forecast long-term performance under loading. The study examines several rehabilitation methods, including full-depth reclamation (FDR), cold in-place recycling (CIR), and mechanical stabilization using cementitious additives. Each method is evaluated based on structural capacity enhancement, cost-efficiency, and service life extension. Results demonstrate that the selection of reclamation techniques tailored to subgrade conditions and traffic loads significantly improves structural performance and minimizes maintenance needs. The study concludes that full-depth repaving offers the most sustainable and economically viable solution for restoring the targeted roadway section.


Mohamed Ali Milad karm Salem, Abdalla Ali Agwila, Abdelbaset M. Traplsi, (05-2025), Journal of Alasmarya University: Applied Sciences: Journal of Alasmarya University: Applied Sciences, 2 (10), 118-134

Analytic Modeling to Study the Insolation Heat Gain of Semi Insulated Building in Hot Climate
Journal Article

Countries located in temperate, hot and arid climates, such as Libya, face the critical need to cool houses whose internal temperatures rise due to these climatic conditions. This can be achieved by employing proper insulation techniques to prevent heat gain from solar radiation (insolation). This paper addresses the impact of not implementing thermal insulation for the roof of a building, in contrast to other external parts of the structure. The temperature distribution in a single-story building was studied using finite element analysis (FEA), along with how the building absorbs heat from its surroundings during a sunny day. The thermal analysis was conducted on a 3D concrete building with walls made of concrete masonry blocks, a floor height of 3.20 meters, and a total area of 40 square meters, using ANSYS 2020 R2 software. The building model includes thermal insulation for the external envelope, but the roof and openings remain uninsulated (as is often the case with home insulation practices in Libya). The finite element method is widely used due to its high effectiveness in simulation and achieving accurate results. The analysis results demonstrated the heat distribution gained from insolation, as well as variations in the rates of heat transfer from the building's exterior to its interior. The findings showed that neglecting the thermal insulation of the roof and window openings leads to an approximate 70% increase in the building's internal temperature. Furthermore, the results clearly indicated that insulating the building's walls alone is insufficient to prevent overheating. This provides a sufficient understanding of the prioritization required in applying insulation layers for buildings located in hot climates.

Mohamed Ali Milad karm Salem, (05-2025), Academy journal for Basic and Applied Sciences (AJBAS): Academy journal for Basic and Applied Sciences (AJBAS), 1 (7), 1-5

مؤشر حالة الرصف لتقييم وإعادة تأهيل الطرق
مقال في مؤتمر علمي

إن شبكات الطرق لها تأثير على اقتصاد ونهضة البلدان لذلك تسعى الجهات الحكومية والاقتصادية للحفاظ على الطرق وحمايتها من التدهور والمحافظة أيضا على معايير جودة وسلامة الطرق.و نظرا لتعرض الطرق الى العديد من الاضرار التي تسبب في إنقاص عمرها الافتراضي, لذلك من المهم تقييم حالة الطريق والتنبؤ بمستوى التدهور الذي قد يصل اليه مستقبلا. ويمكن الحفاظ على الطريق في صورة مرضية خلال العمر التصميمي له بالصيانة الدورية في وقتها وإذا لم تتم الصيانة أو في حالة تأخرها ستؤدي الي زيادة تدهور الطرق وزيادة تكاليف الصيانة الذي قد تصل زيادتها الى 3 أضعاف لأنها قد تتحول من صيانة وقائية الى إصلاح وإعادة التأهيل. لذلك اجريت العديد من الدراسات لمساعدة متخدي القرار في اختيار المكان والتوقيت المناسب من خلال جمع البيانات عن الاضرار التي تظهر بالرصف مع مرور الوقت وتحويلها من مساحات واطوال واعماق متفرقة الى قيمة واحدة (مؤشر) معبرة عن حالة الرصف. وهناك الكثير من المؤشرات المستخدمة للتقيم تتفاوت في منهجيتها ومن اهمها مؤشر حالة الرصف. وتهدف هذه الدراسة الي استعراض اهم ما جاء في الدراسات السابقة الخاصة بتقييم حالة الرصف باستخدام مؤشر حالة الرصف وذلك لابقاء الرصف في حالة جيدة و لتجنب التكاليف الباهضة الناتجة عن اهمال الصيانة وتحديد أولويات ونوع وتوقيت الصيانة للطرق واحتياجاتها المستقبلية لتوفير الامن والراحة والسلامة المرورية لمستخدمي الطريق. 

اسماعيل قودان علي نايل، رجاء عبدالغني أعقيل، (05-2025)، المؤتمر العاشر لمواد البناء والهندسة الانشائية: جامعة سرت، 392-399

Study to produce a material for rehabilitation of concrete structure using local material
مقال في مجلة علمية

Abstract

Most concrete buildings face many different conditions that allow cracks to grow in concrete structural elements, causing deviations in the main stresses of the design sections that negatively affect the life of these structures. Therefore, it is necessary to focus on the restoration, strengthening, repair, strengthening and rehabilitation of these damaged concrete buildings because of the historical, cultural or functional value that these concrete structures represent that meet the needs of the contemporary infrastructure of society and to find appropriate solutions to ensure their safety and serviceability in addition to increasing their strength and solidity and extending their life. This study included the development of a cement material that uses locally sourced components in addition to steel fibers and some chemical additives to produce a material that reduces the various challenges associated with this task. The results were successful, in addition to the fact that the study opened other research horizons in this aspect to increase research on the best and most appropriate effective and sustainable solutions. In this study, a set of laboratory tests were conducted that were relied upon for the research, and included testing the basic materials: cement, fine sand, water, super plasticizer additives, and silica dust, and performing a compressive strength test on regular concrete samples and samples of cement mixtures improved by adding steel fibers, the super plasticizer, and silica dust. Based on the results obtained, the study presents the possibility of obtaining an improved cement mixture that can be used in rehabilitating concrete structures and structures. The study also included some recommendations that can be used to further develop the improved cement mixture using a group of additives present within the Libyan state.

محمد عاشور علي عيواز، (05-2025)، مجلة كلية طرابلس للعلوم والتقنية: مجلة كلية طرابلس للعلوم والتقنية، 12 (1)، 1-13

Double Knife-Edge Diffraction Model for Analyzing Human Body Shadowing Effects in Fifth Generation Wireless Systems
Conference paper

This paper addresses the critical challenge of human-induced signal attenuation in millimeter-wave (mmWave) communications, a key concern for fifth-generation (5G) network reliability in indoor environments. Our study introduces a simplified model to quantify the impact of human body blockage on indoor communication links at a frequency of 32.5 GHz., a frequency relevant to 5G systems. The influence of nearby scattering objects is investigated through experimental measurements involving a human body. Key wave propagation phenomena, including diffraction, are considered for each scattering object. The Double Knife-Edge Diffraction (DKED) model is used to estimate the attenuation caused by the human body (to estimate blockage losses). Through controlled experiments with human subjects, we systematically analyze how scattering objects and body positioning influence signal propagation. The model's performance is validated by comparing simulation results with experimental data. The findings show that the proposed model effectively predicts signal attenuation in indoor environments, providing valuable insights for future studies on human presence effects in fifth-generation (5G) communication systems. Keywords: 5G, DKED, diffraction, human shadowing, millimeter-wave, blockage.

Ahmed Hassen ELjeealy Ben Alabish, (05-2025), 10th International Conference on Control Engineering &Information Technology (CEIT-2025) Proceedings Book Series –PBS- Vol 23, pp.145-151: (CEIT-2025), 145-151

Impact of Human Body on Knife-Edge Diffraction in Wireless Communication
Conference paper

-This paper examines the effect of human body blockage on signal propagation (millimeter-wave (mmWave) signal propagation) in indoor environments links at 32.5 GHz (a critical frequency for fifth-generation (5G) network), with a particular focus on the diffraction effects caused by the human body, where diffraction is one of the important wave propagation mechanisms. In this study, measurements were taken to assess the effect of the human body as it moves between the transmitter and the receiver. To predict the signal attenuation, the principles of Fresnel diffraction were utilized, particularly emphasizing complex Fresnel integrals. Our results show that the received power varies significantly based on the person’s position, as diffraction loss highly depends on the body’s location. This study enhances our understanding of how human-induced diffraction, is critical for designing more reliable wireless networks. As the findings demonstrate that the proposed model effectively predicts signal attenuation in indoor environments and emphasizes the importance of accounting for human interference when optimizing communication systems, thus supporting the effective deployment of 5G technology. 

Ahmed Hassen ELjeealy Ben Alabish, (05-2025), 10th International Conference on Control Engineering &Information Technology (CEIT-2025) Proceedings Book Series –PBS- Vol 23, pp.162-169: (CEIT-2025), 162-169

Evaluating the Accuracy of DKED and Fresnel Diffraction Models for Human Body Blockage in Indoor 5G Band Communications
Conference paper

This paper investigates human-induced signal attenuation in indoor mm-wave communications at 32.5 GHz, a critical concern for 5G systems. Two distinct diffraction-based models are applied to the same indoor scenario to assess human blockage effects: one employs the Double Knife-Edge Diffraction (DKED) approach, and the other uses Fresnel diffraction principles with complex Fresnel integrals. Controlled experiments with a human subject moving between a transmitter (TX) and a receiver (RX) reveal that the DKED model consistently underestimates the received power by 2 6 dB, while the Fresnel diffraction approach underestimates it by 2–5 dB Based on the comparative results, the DKED model demonstrates higher accuracy in predicting signal attenuation, offering valuable insights for improving indoor 5G network performance

Ahmed Hassen ELjeealy Ben Alabish, (05-2025), Academy journal for Basic and Applied Sciences (AJBAS): Academy journal for Basic and Applied Sciences (AJBAS), 70-75

تأثير أساليب تدريس مادة اللغة الإنجليزية على درجات طلاب المدارس الثانوية بمراقبة تعليم صرمان
مقال في مجلة علمية

تهدف هذه الدراسة إلى فحص تأثير أساليب التدريس على الأداء الأكاديمي لطلاب المرحلة الثانوية في مادة اللغة الإنجليزية بمدينة صرمان ضمن مراقبة تعليم صرمان. اعتمد البحث تصميمًا مختلطًا يجمع بين الأساليب الكمية والنوعية، حيث جُمعت البيانات من 234 مشاركًا شملت تسعة مديري مدارس ثانوية، و45 مدرسًا للغة الإنجليزية، و180 طالبًا. استخدمت الدراسة استبيانًا مهيكلًا للمعلمين والطلاب، ودليل مقابلات مع المديرين، وعُولجت البيانات الكمية باستخدام الإحصاءات الوصفية في SPSS، بينما حلل الباحث البيانات النوعية موضوعيًا لاستخلاص الفئات الرئيسة.

أظهرت النتائج أن طريقة المحاضرة هي الأسلوب الأكثر استخدامًا بنسبة 19.5%، تلتها الأسئلة والأجوبة (16.4%) والعمل الجماعي (14.4%)، في حين كانت أساليب العرض والدراما أقل تطبيقًا. وأفاد 60.6% من الطلاب بأن طرق التدريس غير فعّالة، مقابل 29.4% رأوا أنها فعّالة و10% أنها فعّالة جدًا. وعزا الطلاب عدم الفعالية إلى قلة التفاعل الحقيقي وبروز نشاطات جانبية لا تخدم المحتوى، فيما أشار المديرون إلى أن الطرق المتنوعة تؤثر إيجابيًا على ثقة الطلاب واحتفاظهم بالمعلومات، أو سلبًا إذا لم تتناسب مع قدراتهم المعرفية.


هاجر علي محمد الصقر، د.محمود بلقاسم محمد البوسيفي، (04-2025)، 28-10-2025: المجلة الأفريقية للدراسات المتقدمة في العلوم الانسانية والاجتماعية، 4 (4)، 455-464

Evaluation of Diabetic Cardiac Autonomic Neuropathy in Libyan Patients: Cross‐Link with Biochemical and Clinical Risk Factors
Journal Article

Diabetic cardiac autonomic neuropathy (DCAN) is a significant condition that affects cardiovascular health worldwide and is associated with increased morbidity and mortality rates. Therefore, early detection and management of DCAN are crucial for reducing the risk of cardiovascular disease among individuals with T2DM. Identifying this disorder can enhance patient outcomes and quality of life by minimizing the chances of serious complications. This cross-sectional study aims to identify diabetic individuals with DCAN and to investigate its relationship with various risk factors, including hyperglycemia, the duration of diabetes, the presence of peripheral somatic neuropathy, and diabetic microvascular complications. The study included 261 patients with T2DM, comprising 61.5% females and 38.5% males. Participants underwent cardiovascular testing and clinical evaluations to identify cases of cardiac autonomic neuropathy. Out of the 261 randomly selected patients, 82 were diagnosed with DCAN, resulting in a prevalence rate of 31.4%. The average age for female patients was 57.5 ± 0.7 years, while for male patients, it was 56.3 ± 1.2 years from the total recruited patients. In addition, there is a strong association between DCAN and clinical and biochemical parameters such as lipid profile, duration of diabetes, poor diabetic control, and presence of microalbuminuria in patients with DCAN and above 60 years old, compared to younger patients. The study highlighted a strong association between DCAN and factors such as poor glycemic control, prolonged diabetes duration, and the presence of chronic microvascular complications, including neuropathy, retinopathy, and nephropathy. These findings emphasize the importance of raising awareness and proactively assessing Libyan patients who are at risk for cardiovascular autonomic neuropathy. This is crucial to reduce the likelihood of recurrent acute cardiac complications, especially in patients undergoing emergency surgery without a prior diagnosis. It is vital to recognize this risk.

Keywords. Type 2 Diabetes Mellitus, Pulse Rate, Metabolic Syndrome, Blood Pressure.

Bahaedin Mustafa Ramadan Ben Mahmud, Najwa Al Tashani, (04-2025), طرابلس: Alqalam Journal of Medical and Applied Sciences., 8 (2), 555-561