Abstract

Over the past decades, the urban heritage of Libyan old cities has faced numerous challenges, including functional imbalances, economic, cultural, and social transformations, as well as several intertwined factors threatening the fragile structures of these heritage cities. Despite the severity of the situation, heritage preservation efforts have been limited to restoring a few buildings classified as having high historical and symbolic value. This reflects the inadequacy of the adopted policies and procedures in safeguarding these multi-layered urban structures and ensuring their transmission to future generations. This study focuses on the case of Old Derna, which has suffered from successive factors of decline, leaving the city in a critical and deteriorated condition in recent years. The research aims to highlight the importance of preserving the heritage of Old Derna in the face of ongoing threats of degradation, and to explore preliminary steps that could pave the way toward a balanced and sustainable preservation strategy that ensures the reconstruction of the old city while maintaining its historical identity. Keywords: Old City – Heritage – Preservation – Sustainability – Derna – Decline Factors – Urban Transformations.

Abstract

Benghazi has faced decades of delayed development plans, resulting in entire residential neighborhoods lacking essential services, or having deteriorated services exceeding their lifespan, compounded by war-related destruction. Addressing this requires a comprehensive and dynamic national reconstruction project, based on a scientific and flexible strategy with prioritized implementation and funding alternatives, supported by a trained management team capable of analyzing economic, social, political, human, and financial resources, in line with sustainable development principles. This study proposes the creation of a comprehensive database covering all service and production sectors in the city, including evaluation of above-ground and underground infrastructure, water and energy networks, human resources, and training needs. Detailed data on residential neighborhoods, population, housing units, and available services are also included. This data forms the basis of an electronic system for data analysis and decision support in reconstruction and sustainable development. The system facilitates monitoring project execution, setting priorities, selecting optimal technical and financial alternatives, scheduling budgets, and provides dynamic updates to ensure reliability for future development projects. Keywords: Reconstruction – Infrastructure – Data – Analysis – Sustainable Development – Project Management.

Abstract

Stone columns (SCs) are widely used as an effective technique to enhance the engineering performance of poor soils. The process enhancement of soils using stone columns is accomplished by the consolidated acceleration of weak soils through shortened drainage paths, increasing the load-bearing capability and decreasing settlement by addition of robust granulated materials. Despite the existence of several methods for assessing the bearing capacity of reinforced soils, predicting the behaviour of stone columns is prone to peculiar challenges that require comprehensive analysis. This paper reviews previously published literature on granular columns and includes various efforts to analyse and model weak treated grounds comprised of partially or fully penetrated, single or collections of granular columns. The paper also compares the differences between the most common design methods for assessing the bearing capacity of stone columns. Finally, the review guides engineers on the procedures and considerations to apply during system design. Keywords: Bearing Capacity, Granular Piles, Stone Column, Failure Mechanism.

Abstract

The majority of centralized wastewater treatment plants in low-income countries require rehabilitation or renovation over the next decade. In most cases, centralized treatment plants generate long-term financial burdens for governments and local administrations. Therefore, decentralization appears to be a reasonable solution, referring to systems that serve small areas of urban zones based on hydrology, terrain, and local ecological concerns. Sustainable decentralized treatment emphasizes on-site treatment and material recycling, contributing to achieving sustainable development goals, particularly SDG6 – Clean Water and Sanitation. The Biological Aerated Filter (BAF) technology is attractive and well-suited as a decentralized wastewater treatment system, capable of removing carbonaceous matter and nutrients through biomass growth on support media surfaces, as well as physical removal of suspended solids in a single stage. It can also be applied for secondary and tertiary stages of treatment. This study reviews the performance of three filtration media: activated carbon, sand, and ceramic particles, all used as attached growth zones in BAFs, to create low-cost bio-filtration beds and improve effluent quality. Results indicate that all three filtration media-based beds performed excellently in carbonaceous matter removal and nitrification at a hydraulic retention time of 12 hours with 100% influent recirculation. The research was conducted at Colentina Laboratories, Faculty of Hydrotechnics, Technical University of Civil Engineering Bucharest, Romania. Keywords: Biological Aerated Filter, Carbonaceous Matter Removal, Nitrification.

Abstract

The development of the economy in most countries is related to projects in the construction industry carried out by various contractors. Currently, the objectives of construction projects have slightly shifted and become more challenging, considering that projects should prioritize sustainability. Multiple factors such as climate change, limited non-renewable energy sources, and increasing population affect the present situation, making sustainability a key priority, especially in construction projects. This statistical study aims to determine the understanding of the concept of sustainability, the current practices in the Libyan construction industry, and the related obstacles, providing recommendations for prevailing issues while contributing to the knowledge base of the construction sector in Libya. The research focuses on the current use of green materials in construction projects in Benghazi, Libya, as well as the challenges of applying green materials. Respondents include contractors, clients, and consultants. Keywords: Sustainability, Construction Project, Construction Industry, Climate Change, Non-Renewable Energy, Green Material.

Abstract

Benghazi North power plant is subjected to large ambient air and seawater temperature fluctuations throughout the year, adversely impacting performance and generated power, consequently increasing CO₂ emission rates. Stabilizing the inlet air temperature and controlling the condenser inlet cooling water temperature under design conditions enhances and maintains performance and efficiency year-round. A single-effect water-lithium bromide absorption cycle powered by a solar parabolic trough collector was implemented. For efficient operation during non-sunny periods, an insulated thermal storage tank stores the thermal energy of the working medium, with an assisting heat supply from HRSG downstream exhaust gases to compensate any temperature drop inside the tank, which must not fall below 80°C to ensure effective cooling system operation. Model results indicate an improvement of overall efficiency by 3.635% and generated power by 12.18%, reducing greenhouse gas emissions by 3.537%. Annual power output increased by 9.767% and 7.728% for standalone gas turbines and combined cycle power plants, respectively, and net electricity production increased by 141,358,530 kWh/yr, saving $14,135,853 annually. Despite relatively high capital costs, the payback period is 1.48 years at an energy selling price of $0.1/kWh. The annual solar contribution factor of the parabolic trough system reached 91.896% during sunny periods. Keywords: Solar Cooling, Plant Efficiency, Renewable Energy, Pollution Reduction, Power Production.