A numerical investigation was performed on triangular solar air collectors by integrating unique layouts of triangular and alternating triangular copper metal foams with graded and non-graded pore densities. A three-dimensional CFD model was established to solve the governing equations of coupled systems for porous and non-porous domains. The two-energy-equations model was implemented to simulate heat transfer in porous media. The mathematical model was validated with numerical and experimental tests, with maximum mean absolute percentage error of 5% and 7%, respectively. To compromise heat transfer improvement with pressure losses, a partial metal foam insertion was adopted, covering 10% to 25% of the air duct volume. The findings indicate
... Show MoreThe enhancement of the thermal and thermo-hydraulic performance of a semi-circular solar air collector (SCSAC) is numerically investigated using porous semi-circular obstacles made of metal foam with and without longitudinal porous Y-shaped fins. Two 10 and 40 PPI porous material samples are examined. Three-dimensional models are built to simulate the performance of SCSAC: model (I) with clear air passage; model (II) with only metal foam obstacles, and model (III) with metal foam obstacles as well as porous Y-fins. COMSOL Multiphysics software version 6.2 based on finite element methodology is employed. A conjugate heat transfer with a (k-ε) turbulence model is selected to simulate both heat transfer and fluid flow across the entir
... Show MoreA comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respective
... Show MoreThe objective of this review was to describe the COVID-19 complications after recovery.
The researchers systematically reviewed studies that reported post-COVID-19 complications from three databases: PubMed, Google Scholar and the World Health Organization (WHO) COVID-19 database. The search was conducted between 21 November 2020 and 14 January 2021. Inclusion criteria were articles written in English, with primary data, reporting complications of COVID-19 after full
This review highlights recent advances in the development and use of eco-friendly polymeric membranes made from polymer blends for treating oily wastewater, a major source of environmental pollution. Among treatment options, membrane separation stands out because of its high efficiency and ability to selectively remove oil from water using semi-permeable barriers. The focus of this review is on polymeric membranes derived from polymer blends, which show improved mechanical strength, thermal stability, and resistance to fouling. Additionally, the role of nanomaterials such as titanium dioxide, graphene oxide, and iron nanoparticles is discussed for their ability to boost membrane porosity, permeability, and oil separation efficiency.
... Show MoreFetal growth restriction is a significant contributor to fetal morbidity and mortality. In addition, there are heightened maternal risks associated with surgical operations and their accompanying dangers. Monitoring fetal development is a crucial objective of prenatal care and effective methods for early diagnosis of Fetal growth restriction, allowing prompt management and timely intervention to improve the outcomes. Screening for Fetal growth restriction can be achieved via many modalities; it can be medical, biochemical, or radiological. Some recommended combining more than one for better outcomes. Currently, there is inconsistency about the best method of Fetal growth restriction screening. In this review, a comprehensive
... Show MoreIn recent years, the evolution of the community structure in social networks has gained significant attention. Due to the rapid and continuous evolution of real-world networks over time. This makes the process of identifying communities and tracking their topology changes challenging. To tackle these challenges, it is necessary to find efficient methodologies for analyzing the behavior patterns of dynamic communities. Several previous reviews have introduced algorithms and models for community detection. However, these methods have not been very accurate in identifying communities. Moreover, none of the reviewed papers made an apparent effort to link algorithms that can accurately detect dynamic communities. This review aims to present a ta
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