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Go to Editorial ManagerChemical additives and polymeric materials, selected for their compatibility and ability to improve asphalt's performance in demanding environments. Key additives, including Polyphosphoric Acid (PPA), Polyvinyl Acetate (PVAC) beads, Maleic Anhydride (MA), and Ethylene Vinyl Acetate (EVA) resin, were mixed in precise ratios with the asphalt binder. These additives were chosen to evaluate their effects on crucial performance indicators, such as the Penetration Index (PI) and activation energy, which measure the material’s thermal stability, flexibility, and resistance to deformation. Results demonstrated that the addition of these materials significantly increased the asphalt’s activation energy by up to 45.44%, enhancing its resistance to temperature fluctuations and providing better stability under various environmental stresses. The Penetration Index (PI) also improved notably, indicating that modified asphalt exhibits greater durability and reduced susceptibility to cracking or deformation under thermal changes. These enhancements contribute to lower road maintenance requirements and support greater energy efficiency in asphalt production and application processes. Compared to neat asphalt, the modified asphalt exhibited superior thermal stability, mechanical resilience, and overall performance, making it suitable for use in diverse climatic conditions. This study provides valuable insights into sustainable asphalt modification techniques, emphasizing the role of polymer and chemical additives in extending pavement lifespan and reducing environmental impact through improved material properties.
The process of increasing the heat transfer coefficient, resulting in enhancing system efficiency, is known as heat transfer enhancement. Enhancing heat transport is both economically beneficial and a considerable energy conservation problem. To improve heat transfer, many passive components are utilized within tubes, including wire plugs, enhanced surfaces, rough edges, twisted tape inserts, and liquid additives. This study evaluated twisted tape inserts, which are highly effective passive devices. Considering its numerous advantages, such as effortless maintenance, uncomplicated operation, and straightforward production. The twisted tape inserts within the tube generated a vortex and swirling flow. The interior convective heat transfer process is significantly improved. A summary of various twisting tape additives that can boost performance.
In recent decades, many factors have emerged in the building design field, as the technology development after the industrial revolution has left many environmental problems affecting building environments and turning them into unhealthy ones. Also, the issues of consuming natural resources required innovative and modern solutions to address, which needed the guidance and focus of researchers, engineers, and many other relevant disciplines to find the best treatments to solve them. One of the essential treatments was using advanced smart technology to solve the environmental problems of buildings, such as providing thermal comfort and reducing energy consumption. The concept of adaptive smart envelopes is one of this manifestation of advanced technology in the field of building design characterized by interaction and adaptation to the surrounding environment through the application of many technologies which it works to improve its environmental efficiency. The research aim was to simulate the changes in the building environment, which is treated by covering the building with an adaptive smart envelope by using the Rhinoceros Grasshopper programme.
Millimeter Wave (mmWave) Massive Multiple Input Multiple Out (MIMO) system is a key technology for future wireless transmission. The system's architecture can differ based on the type of Analog-to-Digital Converters (ADCs) used at the receiver, whether they are all low-resolution or a mix of different resolutions (Mixed-ADCs). Mixed-ADCs is a promising solution to achieve better performance than low-resolution ADC-only architectures by leveraging high-resolution ADCs to capture critical signal components while maintaining energy efficiency through low-resolution ADCs. In this paper, the problem of channel estimation for this system architecture is taken into consideration. A novel compressive-sensing based algorithm, that is called Approximate Conjugate Gradient Pursuit (ACGP), is proposed to estimate the channel coefficients. The performance of the proposed algorithm is investigated under varying system parameters, including different Signal-to-Noise Ratios (SNR), Radio Frequency (RF) chains, ADC resolutions, and numbers of observation frames. Matlab software was used to perform numerical simulations. The results demonstrated that mixed-ADCs architecture outperforms low resolutions only in performance. It was found that ACGP achieves lower Minimum Mean Squared Error (MMSE) compared to Orthogonal Matching Pursuit (OMP) and Least Square (LS), particularly in low SNR conditions showcasing its robustness and efficiency in signal reconstruction, achieving an average enhancement of 30% to 50% at moderate SNR levels. While OMP exhibited faster computation times under various number of observation frames, ACGP maintained stable computational performance, with a slight increase in computation time. For applications where accurate channel estimation is required under noisy environment, the proposed algorithm is an effective choice to meet such requirements.