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A numerical simulation aiming to study and investigate flow behavior over a high lift low speed airfoil type AG-16 at various angles of attack ranging from 0 degree to 15 degree and constant Reynolds number “39,709” was performed. Computational fluid dynamic CFD technique was applied to study the flow characteristics around the complicated shape airfoil; for better calculation results and smoother meshing generation process unstructured mesh with tetrahedron grid element was used. SOLIDWORKS program was used for modeling requirements; the modeling process includes designing three-dimensional wing with airfoil cross section AG-16 to take into account the influence of third dimension on the flow variables. The magnitude of adverse pressure gradient and flow separation point was investigated, the critical/stall angle of attack of this type airfoil was specified and the aerodynamic efficiency was studied and analyzed with respect to various angles of attack. The numerical results illustrate that the lift coefficient rise rapidly with decreasing angle of attack. The critical angle of attack that gives the maximum lift was recorded at 14 degree on the other hand the drag increased rapidly at high angles of attack due to flow separation, the optimum angle of attack that provide the maximum aerodynamic ratio was 4 degree.

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There is a critical need in orthopedic and orthodontic clinics for enhanced implant-bone interface contact to facilitate the quick establishment of a strong and durable connection. Surface modification by bioactive multifunctional materials is a possible way to overcome the poor osteoconductivity and the potential infection of Ti-based implants. Ti-25Zr biometallic alloy was prepared by powder metallurgy technique and then coated by Nano-composite fiber using electrospinning. Ceramic Nanocompound (CaTiO3, BaTiO3) was used as filler material and individually added to polymeric matrices constructed from the blend of polycaprolactone/chitosan. Using optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and wettability, respectively, the morphology, chemical analysis, surface roughness, and contact angle measurements of the samples were evaluated. The result shows a significant improvement in cell viability, proliferation, and ALP activity for coated samples compared to noncoated samples. PCL/Chitosan/Nano-CaTiO3 (CA1) recorded remarkable enhancement from the surface-coated samples, demonstrating a significantly higher cell viability value after seven days of MC3T3-E1 cell culture, reaching 271.56 ± 13.15%, and better cell differentiation with ALP activity reaching 5.61 ± 0.35 fold change for the same culture time. PCL/Chitosan/Nano-BaTiO3 (BA1) also shows significant improvement in cell viability by 181.63 ± 17.87% and has ALP activity of 3.97 ± 0.67 fold change. For coated samples, cell proliferation likewise exhibits a considerable temporal increase; the improvement reaches 237.53% for (CA1) and 125.16% for (BA1) in comparison with uncoated samples (bare Ti-25Zr). The coated samples resist bacteria in the antibacterial test compared to the noncoated samples with no inhibition zone. This behavior suggests that a Nanocomposite fiber coat containing an active ceramic Nanocompound (CaTiO3, BaTiO3) promotes cell growth and holds promise for orthodontic and orthopedic bioapplication.

ملخص البحث :

Biofunctionalization of an implant using functional ceramics with exceptional electrical characterization, such as BaTiO3 and SrTiO3, has gained considerable attention in creating a composite coating with bio-polymer to activate metal implant surfaces for bone tissue engineering applications and, at the same time, resist bacterial infection. A Ti–Zr alloy sample was created by powder technology, and then a coating was applied using the electrospinning technique. Individually, nanopowders of ceramic compounds such as nBaTiO3 and nSrTiO3 were added to a blend of polycaprolactone and chitosan to create composite solutions that could be converted into a nanofibrous coating layer using the electrospinning technique. The samples were analyzed for their morphology, chemical composition, surface roughness, dielectric constant, and wettability. The techniques employed were SEM, EDS, FTIR, an LCR meter, and a contact angle goniometer. The samples’ cytocompatibility was assessed by examining the cell viability, ALP activity, proliferation, and attachment of MC3T3-E1 osteoblast cells on both coated and uncoated sample surfaces.The bacterial resistance assays were conducted against Staphylococcus aureus and Streptococcus mutans. The findings demonstrate a notable enhancement in the biocompatibility of the coated specimens following a week of cellular cultivation. The composite coating containing piezoelectric BaTiO3 has a dielectric constant Ɛr (16) close to dry human bone at 100HZ frequency. Cell proliferation increases dramatically with time in coated samples, and the improvement approaches 125.16% for (BA1) and 111.38% for (SR1) as compared to uncoated Ti–25Zr sample. Cell viability percentage for the coated samples is compared with bare Ti–25Zr, which has an 80.52 ± 1.97% crucial increase, while (BA1) has 181.63 ± 17.87 and (SR1) 170.09 ± 18.12%. No zone of inhibition was detected in the bacterial resistance test for the uncoated sample, while the samples with composite coating show an adequate and comparable inhibitory zone. The composite nano-fiber has a strong biocompatibility, and the coating process is simple and economical, holding potential for use in orthodontic and orthopedic bone regeneration applications.

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Using bioactive and biocompatible coatings to biofunctionalized metallic implant surfaces for enhanced bone regeneration while resisting bacterial infection has attracted materials scientists' interest. Bio-metallic Ti-25Zr disc sample was prepared using powder metallurgy and then coated using an electrospinning method to form a nanocomposite fiber as a coating layer over the surface of the metal alloy substrate. Three nano-compounds (Nano-hydroxyapatite, NanoTitanium dioxide, Nano-strontium titanite) were added individually to the Polycaprolactone/Chitosan blend to prepare the electrospinning solutions. The results show a significant improvement in biocompatibility for the coated samples after seven days of (MC3T3-E1) cell culture. Cell viability percentages were significantly higher for the coated samples compared to uncoated ones, with values of PCL/Chitosan/nHA (HA1) has 239.45±17.95%, PCL/Chitosan/nSrTiO3 (SR1) has170.09±8.12%, and PCL/Chitosan/nTiO2 (TI1) has 117.19±19.42%, while bare Ti-25Zr has 80.52±1.97%. Cell proliferation also shows a remarkable increase with time for coated samples, and the enhancement reaches 197.76% for (HA1), 111.38% (SR1), and 45.81 % (TI1) in comparison with (bare Ti-25Zr). For the antibacterial test, no inhibition zone for the control sample (bare Ti-25Zr) was observed, while the coated samples showed a suitable and comparable inhibition zone. The coating procedure is simple and inexpensive, and composite nano-fiber has high biocompatibility and promise in orthodontic and orthopedic bone regeneration.