Iranian Journal of Materials Science and Engineering

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Anodes are critical component of cathodic protection systems. As part of this effort, three different anodes were tested in a cathodic protection system that was designed and constructed to prevent further corrosion of reinforced concrete. This anodic system includes an electrically conductive coating composition applied in fluid form over an outer surface of the concrete mix. The composition further includes a predetermined amount of electrically conductive carbon material (coke, carbon black, graphite) uniformly distributed in the epoxy resin (as a binder) whereby the coating composition has a predetermined value of resistively. This investigation attempts to find the best type and optimum content of conductive carbon filler in poxy coating, to ensure optimal anode working parameters for marine environments (basically marine and sewer environments) and if any of the coating systems tested in this study excel over the other. In this study, electric and electrochemical parameters of three layer (with average coating thickness of 300µm) coke-epoxy, carbon black-epoxy and graphite-epoxy conducting paints (with different amount of filler) have been determined during long-term anodic polarization (70 days) in a seawater solution. During this test, on the basis of impedance measurements, the electrical resistances of these coatings have been calculated every 14 days. if conductive paints exhibit good electric and electrochemical stability, they will be attractive for cathodic protection of reinforced concrete.

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Short banana fiber reinforced composites have been prepared in laboratory to determine mechanical properties. It has been observed that as soon as the percentage of the banana fiber increases slightly there is a tremendous increase in ultimate tensile strength, % of strain and young modulus of elasticity. Reinforcement of banana fibers in epoxy resin increases stiffness and decreases damping properties of the composites. Therefore, 2.468% banana fiber reinforced composite plate stabilizes early as compared to 7.7135 % banana fiber reinforced composite plate but less stiff as compared to 7.7135 % banana fiber reinforced composite plate

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In this study, an epoxy-based nanocomposite reinforced with copper oxide-graphene oxide hybrid was investigated. Initially, the hybrid powder of CuO–GO with a weight ratio of 9:1 was prepared. The hybrid filler with different weight percentages ranging from 0.1–0.5 was used to reinforce the epoxy resin. The prepared samples were analyzed using XRD, FTIR, FESEM, TEM, and tensile testing. According to the XRD results and SEM images, the hybrid powder was successfully prepared, and the mechanical testing results showed an improvement in tensile strength in the composite samples. The best composite sample in terms of tensile strength was the one containing 0.3 wt% of hybrid reinforcement, which exhibited a 73% increase in strength compared to the neat resin sample.

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Today, the application of high‑performance thin‑film nanocomposites as impedance‑matching layers in telecommunication and military technologies has gained substantial importance. In this study, a multiphase nanocomposite comprising Fe₃O₄, ZnTiO₃, and multi‑walled carbon nanotubes (MWCNT) embedded within an epoxy resin matrix was designed and synthesized under carefully controlled laboratory conditions. Experimental data were analyzed using multiple regression analysis alongside error variance reduction techniques to identify the optimal composition among the four finalized sample variants. During the fabrication process, the samples underwent sequential mixing, heating, and sonication steps to ensure proper dispersion of the fillers, followed by casting into molds with dimensions corresponding to the rectangular waveguide test section used for the electromagnetic measurements.Topological and morphological characterizations of the fabricated composites were performed by Scanning Electron Microscopy (SEM), while crystal structure assessments employed X‑ray Diffraction (XRD) analysis. Furthermore, electromagnetic characterization was conducted using WR‑90 waveguide measurements over the frequency range of 8.2–12.4 GHz. Among the samples examined, specimen C4, containing an increased ZnTiO₃ content, demonstrated superior particle dispersion and consequently improved electromagnetic impedance‑matching performance. Numerical simulations carried out with the Frequency Domain Solver of CST Microwave Studio corroborated the experimental findings with considerable agreement. The results identified Fe₃O₄ as the dominant contributor to magnetic loss mechanisms, whereas MWCNTs served as conductive constituents within the composite matrix. The inclusion of ZnTiO₃ markedly enhanced impedance matching characteristics, resulting in a significant reduction of wave reflection and thereby facilitating improved wave energy transmission control across a broad bandwidth. Specifically, for the 1 mm thick C4 sample, the reflection coefficient was reduced to −17.85 dB, while the transmission parameter S₂₁ remained below −0.072 dB at 8.2 GHz, indicating excellent impedance matching and minimal reflective loss. Frequency‑dependent analysis further demonstrated a stable balance between dielectric and magnetic contributions, manifesting in consistent electromagnetic performance without substantial deviation across the measured spectrum. Accordingly, the investigated nanocomposite emerges as a promising candidate for lightweight, high‑performance absorber layers, impedance‑matching layers, and electromagnetic coatings in advanced telecommunication and defense applications.