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Economic load dispatch (ELD) became recently a mandatory tool for reliable and economic power system operation. ELD improves the security of the power supply while minimizing the generation costs. Daily load curve imposes conflicting requirements on ELD scheme, such as fulfilling demand during peak periods while limiting the cost. Demand response (DR) is an intelligent approach that ensures load demand fulfillment without introducing additional costs. DR allows shifting the electricity consumption to the non‐peak periods. Therefore, DR could be considered as a virtual power plant. ELD is usually solved as nonlinear constraint optimization problem. Three simple, fertile, and robust meta‐heuristic optimizations are competing in this article for solving ELD incorporating DR as virtual power plant. These are ant lion optimizer (ALO), particle swarm optimization (PSO), and artificial immune system (AIS). The objectives are minimizing the overall cost, system losses, and emission levels. Variety of distinctive study systems are considered to test the functionality and feasibility of the proposed algorithms; they are 6‐bus, 30‐bus, and 118‐bus IEEE systems. MATLAB environment is used for coding ALO, PSO, AIS, and the systems under concern. The comprehensive results show that incorporating DR in ELD reduces the costs/losses/emissions without affecting the power system security and reliability. The comparative results verify the robustness and reliability of ALO in minimizing the overall operating cost and emission levels of the power systems under concern while confining with the constraints. Moreover, they show that ALO has the highest accuracy and convergence efficiency while enjoying the reduced computation storage and execution time.

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This study is devoted to understand the mechanisms of mineral fillers in asphalt at the mixture and mastic scales. To do so, the physical properties of asphalt mixtures and mastics were evaluated; in addition, a chemical investigation was presented on the mastic scale for the sake of providing insight behind the possible mechanisms between asphalt binder and mineral filler. Three mineral fillers namely hydrated lime (HL), limestone (LS), and cement bypass dust (CD) were incorporated into an asphalt binder at different filler-to-binder (F/B) ratios. For the mechanistic evaluation of the mixtures, the indirect tensile strength (ITS), moisture damage evaluation, resilient modulus, and static creep-recovery tests were carried out. The fracture energies also were quantified for all the studied mixtures. The results of penetration and softening point tests, as well as their pertinent penetration index (PI), were discussed to elucidate some physical properties of the mastics. The nuclear magnetic resonance (NMR) spectroscopy was performed on the mastics to obtain information on molecular structures of the formed composites. The findings of this study emphasize that the physical properties of mixtures and mastics are highly dependent on type and concentration of mineral filler. The 1H-NMR and 13C-NMR results proved that the inclusion of the studied fillers did not change the molecular structure of the base asphalt binder; hereby the physical mechanisms stand behind the attained properties. It is believed that the findings of this work would contribute to growing knowledge of the mechanisms of mineral fillers in asphalt mixtures.

Over the years, researchers have developed many laboratory methods for conditioning and evaluating the moisture damage of asphalt mixtures. Most of the tests do not fully simulate field conditions and the evaluation criterion does not always predict the long-term susceptibility to moisture damage. This paper aims to present a comprehensive conditioning and evaluation method that simulates field conditions to assess the durability of bituminous layers against moisture damage. The equipment consists of a system applying a cyclic load on samples in which water can be forced through. The assessment procedure is based on the Indirect Tensile Strength (ITS) test after the conditioning method, from which the concept of the Damage Rate (Dr) as an indicator for classifying the durability of mixtures against moisture damage, was developed. The method would allow asphalt practitioners to evaluate the mixture for susceptibility to moisture on a routine basis

The aim of this study is to address the feasibility of using Nanosilica (NS) in bituminous pavements from the perspective of asphalt binder and corresponding mixture characteristics. In this paper, the characteristics of asphalt binder containing 0%, 2%, 4% and 6% of NS have been investigated in terms of the penetration, softening point, viscosity, and changes in chemical bonds using the Fourier Transform Infrared (FTIR) Spectroscopy. An additional laboratory study was conducted to characterize the performance properties of the corresponding asphalt mixtures based on the resilient modulus, indirect tensile strength, fracture energy, moisture susceptibility, and fatigue life. Overall, the addition of NS material has a positive influence on different properties of the asphalt binder and mixture and can be used to construct durable pavements, thereby reduce the life-cycle costs of the pavement.