A literature survey on electrical-current-assisted friction stir welding

Electrical-current-assisted friction stir welding (EA-FSW) is a procedure developed for the joining of similar and dissimilar materials. EA-FSW is a newly invented solid-state process to increase welded components’ efficacy in various applications, such as marine structures. EA-FSW joints have investigated the dissimilar joints on aluminum–magnesium, aluminum–steel, and polymer-to-steel. Similar joints have been performed on aluminum, magnesium, and steel. The main parameters that affect the temperature of the nugget in EA-FSW are electrical current and tool rotational velocity. This review paper presents the fundamental principle of EA-FSW, its processes mechanism, and various types of tools, and discusses the different joints that EA-FSW welded. The effect of electrical current on the quality of similar and dissimilar joints is discussed. The simulation process and detailed modeling of the EA-FSW process are discussed in the last section

On the Internal Enrichment Implementation for Non-Convex Paths, Discontinuities and Crack Problems

Studies on the cracked plates have shown high variations in the stress values around the crack tip. On the other hand, micro-cracks are observed in man-made pieces. Thus, analysis of stress fields as well as displacement at the crack tip will be inevitable and very important. Mesh-free methods are new techniques that do not require applying the communication-based concept on what is presented in the finite element method. The discretization of the problem domain is done by a set of node points. In the present study, the Element-Free Galerkin (EFG) method was used to analyze the problems of linear elastic stress field in cracked bodies. Two important and essential measures (steps) were done for increasing the accuracy of the results obtained from the analysis of the problems. In the first step, the standard moving least squares shape function was enriched for capturing discontinuity, using some extra basis functions obtained from analytical solutions.  In the next step, some consideration was applied in the case of confronting non-convex paths and discontinuities. For this purpose, the diffraction method was used to generate suitable shape functions. Finally, the accuracy of the results and proper efficiency of the proposed extended EFG method were assessed by the standard problem analysis and the results of numerical analysis were compared with the theoretical results

Friction Stir Processed AA5754-Al<sub>2</sub>O<sub>3</sub> Nanocomposite: A Study on Tribological Characteristics

This study investigates the tribological properties of an AA 5754 aluminum alloy composite reinforced with the nanopowder of Al2O3, fabricated using the friction stir processing (FSP) technique with blind holes. The aim is to analyze the effects of varying the tool rotational speed (rpm) and blind hole diameter on the wear and friction behavior of the produced composite. A pin-on disk test is conducted under dry conditions and room temperature to assess the tribological properties against steel. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) is employed to examine the worn and wear surfaces of the produced composites post test. The results indicate that increasing the applied load results in a decrease in the coefficient of friction (COF), with values ranging from 0.775 to 0.852 for 10 N and 0.607 to 0.652 for 20 N. Moreover, the wear rate diminishes with higher Al2O3 content and optimal FSP tool rotation (1280 rpm). Hardness analysis reveals variations between 33–42 HV and 35–39 HV, influenced by nanoparticle distribution. The composite demonstrates superior wear resistance compared to raw AA5754 aluminum due to its reinforced nature. However, high FSP tool rotation rates lead to abrasive wear and surface cracks. These findings offer insights into optimizing FSP parameters to enhance the tribological performance of nano-reinforced aluminum alloys

Introducing a new pharmaceutical agent: Facile synthesis of CuFe₁₂2O₁₉@HAp-APTES magnetic nanocomposites and its cytotoxic effect on HEK-293 cell as an efficient in vitro drug delivery system for atenolol

In this study, novel CuFe₁₂O₁₉@hydroxyapatite magnetic nanocomposites (CuFe₁₂O₁₉@HAp MNCs) as controlled target drug delivery were synthesized by ultrasound-assisted precipitation method for the first time. Then, the magnetic substrate was functionalized with APTES (CuFe₁₂O₁₉@HAp-APTES MNCs) to increase the efficiency of the drug delivery system. The crystallinity, size, morphology, and composition of the products were determined by FESEM, DLS, BET, TEM, XRD, EDS, and VSM. In order to investigate the drug loading ability of prepared nanocomposites, we chose antihypertensive drug (atenolol) as the model drug. After that, the release behavior of magnetic nanocomposites modified atenolol was investigated under stomach (pH value of 1.5–2) and intestine (pH value of 5.8–6.7) conditions. The results revealed that the highest entrapment efficiency was achieved by CuFe₁₂O₁₉@HAp-APTES MNCs (63.1%). Furthermore, the controlled-release potential for CuFe₁₂O₁₉@HAp-APTES MNCs was the highest compared with the pure CuFe₁₂O₁₉@HAp MNCs. Increased efficiency can be due to the binding of the amine group in APTES with the atenolol drug. The cytotoxicity of the ATL-loaded magnetic nanocomposites (ATL-CuFe₁₂O₁₉@HAp-APTES MNCs) was investigated on the HEK-293 cell line using MTT assay. Based on the results, we concluded that the synthesized magnetic nanocomposites could be effective vehicles for the sustained delivery of atenolol as an antihypertensive drug

Superior UVC light-mediated catalytic activity of a novel NiFe₂O₄@ TiO₂ magnetic nanocomposite synthesized with green route using Pulicaria Gnaphalodes plant extract for enhanced photocatalytic degradation of an antibiotic in water solution

In this study, the NiFe₂O₄@TiO₂ magnetic nanocomposite was synthesized by the green synthesis method, which is an efficient and economical method. Pulicaria Gnaphalodes plant extract was used for nanocomposite synthesis because this method is suitable for the biosynthesis of nanocomposites on a large scale, and the nanocomposite produced by plants is more stable. The efficiency of the synthesized nanocomposite was investigated for the photocatalytic degradation of Penicillin G (PNG) under UVC light irradiation in aqueous solutions. The structural characteristics of this nanocomposite were determined by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and dynamic light scattering. The effect of different parameters including pH, nanocomposite dose, penicillin G concentration and time were studied to reach optimum conditions. About 71% of PNG in optimal conditions (pH = 9, nanocomposite dose = 0.6 g/L, and penicillin G concentration = 10 mg/L) was decomposed. Generally, the NiFe₂O₄@TiO₂ nanocomposite can be used as an efficient catalyst for the degradation of PNG in aqueous solutions

Green synthesis of iron nanoparticles using Pistacia-atlantica leaf extract for enhanced removal of Cr(VI) from aqueous solution

The discharge of chromium-containing wastewater from various industries into aqueous environments is regarded as an important and challengeable matter due to its high toxicity. The application of conventional methods for eliminating this pollutant are often very expensive and difficult. Therefore, the adsorption process has been introduced as a desirable and effective method for removing chromium ions from aqueous media. In this research, iron nanoparticles (Fe-NPs) were synthesized using Pistacia-atlantica leaf extract as a reducing agent, then they were characterized by DLS, XRD, FT-IR, FESEM/EDS, and TEM techniques and its effectiveness to eliminate hexavalent chromium (Cr (VI)) from aqueous solutions was carried out. The capability of the batch adsorption procedure was assessed under different operational factors, such as initial pH, adsorbent dose and initial Cr (VI) concentration. Optimum adsorption conditions were determined at initial pH of 2, Cr (VI) concentration of 25 mg Lˉ¹ and adsorbent dose of 0.24 g Lˉ¹. Based on the obtained results, the highest removal efficiency (99.9%) by the adsorption process was occurred at pH of 2, concentration of 5 mg Lˉ¹ and 30 min of operational time. On the other hand, the results showed that the percentage of the pollutant elevated by increasing the contact time and amount of adsorbent dose, whereas that of was declined by increasing the initial concentration of Cr (VI). Besides, the experimental equilibrium data was evaluated by Langmuir, Freundlich, and Temkin isotherm models, and the outcomes revealed conformity with the Langmuir isotherm model. The Cr (VI) adsorption utilizing Fe-NPs adhered to a pseudo-first-order kinetic model. Eventually, thermodynamic studies demonstrated that the adsorption of Cr (VI) onto the surface of the Fe-NPs is endothermic and spontaneous

Phyto-assisted synthesis of magnetic NiFe₂O₄ nanocomposite using the Pulicaria gnaphalodes methanolic extract for the efficient removal of an antibiotic from the aqueous solution: a study of equilibrium, kinetics, isotherms, and thermodynamics

In this research, the magnetic NiFe₂O₄ nanocomposite was synthesized using Pulicaria gnaphalodes methanolic extract and applied to remove penicillin G from aqueous solutions. The results of field emission scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared, Vibrating-Sample Magnetometer (VSM), and energy-dispersive spectroscopy-mapping analyses showed that this nanocomposite was well synthesized with a size of approximately 50–70 nm. The maximum adsorption capacity of the magnetic NiFe₂O₄ nanocomposite was 22.95 mg/g under optimal conditions. In addition, the experimental data of penicillin G adsorption by the magnetic NiFe₂O₄ nanocomposite showed that ΔH and ΔS values were positive and ΔG was negative and were following the Temkin isotherm model with R² ¼ 0.99 and follows the pseudo-second-order kinetic model

An efficient biosynthesis of novel ZnO/CuO nanocomposites using berberis vulgaris extract (ZnO/CuO@BVENCs) for enhanced photocatalytic degradation of pollution, antibacterial and antifungal activity

In this study, an environmentally-friendly method was employed to synthesize ZnO/CuO nanocomposites using berberis vulgaris extract, resulting in ZnO/CuO@BVE NCs. The structure and properties of the ZnO/CuO@BVE NCs were characterized using various analytical techniques including XRD, UV-DRS, FESEM, FT-IR, EDAX, and TEM. UV-DRS results highlighted a bandgap energy reduction from 3.11 eV to 2.93 eV due to CuO integration with ZnO. TEM images confirmed the nanocomposite size to be between 35–50 nm. To evaluate the photocatalytic effectiveness of the biosynthesized nanocomposites, rhodamine b (RhB) was used as a representative contaminant. We thoroughly investigated the influence of multiple variables such as dye concentration, nanocatalyst amount, light source, and pH on the photocatalytic degradation of RhB. Under optimized conditions (0.15 g/L nanocatalyst, pH 11, UV light, and 3 ppm pollutant concentration), a remarkable 97.3% RhB degradation efficiency was achieved. Additionally, the antibacterial properties of the ZnO/CuO@BVE NCs were tested against six ATCC strains. Notably, they exhibited strong antibacterial action, especially against K. pneumoniae and P. aeruginosa, with a minimum inhibitory concentration (MIC) as low as 62.5 μg/mL. Furthermore, the nanocomposites demonstrated significant antifungal activity against C. albicans with an MIC of 31.2μg/mL. This research emphasizes the potential applications of ZnO/CuO@BVE NCs in environmental remediation and medical fields

Pulicaria gnaphalodes-assisted green synthesis of NiFe₂O₄@ZnO nanocomposites for sustainable remediation of an antibiotic from aqueous solution

In this study, the NiFe₂O₄@ZnO nanocomposite was synthesized in a simple, accessible and affordable method using Pulicaria gnaphalodes plant extract as a reducing agent. The structural characteristics of this nanocomposite were determined by transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, X-ray energy diffraction spectroscopy and dynamic light scattering. TEM micrograph confirmed the formation of spherical and cubic spinel ferrite with average dimensions of 75–85 nm. Some parameters such as pH, dose of NiFe₂O₄@ZnO nanocomposite, concentration of penicillin G and reaction time to reach optimal conditions were investigated. According to the results of the present research, the photocatalyst process along with the use of NiFe₂O₄@ZnO nanocomposite as an oxidizing agent is an effective method in degradation of the penicillin G antibiotic from aqueous solutions

Green synthesis of non-toxic silver nanoparticles using Salvia tebesana Bunge extract: Optimization, cytotoxicity, and antibacterial activities

The remarkable antibacterial activity and potential biomedical applications of silver nanoparticles (AgNPs) synthesized through eco-friendly approaches have garnered significant attention in recent years. This research aimed to introduce a green synthesis method for AgNPs using Salvia tebesana (S. tebesana) Bunge extract and to investigate their properties, antibacterial activities, and cytotoxicity effects. The fabricated AgNPs were analyzed with various analyses, including UV–Vis, DLS, XRD, FT-IR, and TEM analysis. The broth microdilution assay was applied to measure the Minimum Inhibitory Concentrations (MIC) of chemical AgNPs, biosynthesized AgNPs, and S. tebesana Bunge leaves extract alone against selected standard bacteria strains. The biosynthesized AgNPs displayed a surface plasmon resonance peak at approximately 415 nm, and the AgNPs synthesized using S. tebesana Bunge extract had a spherical configuration with an average size in the range of 10–15 nm. Biosynthesized nanoparticles showed a noteworthy antibacterial activity compared to chemical nanoparticles, particularly against P. aeruginosa, with the highest antibacterial activity reported at a MIC value of 39.06 μg/mL. AgNPs synthesized using S. tebesana Bunge extract demonstrated a significant decrease in fibroblast cell viability, but only when the concentration reached 2 mg/mL. The findings demonstrate that S. tebesana Bunge leaves extract enhances the antibacterial properties of AgNPs, and also represents an appropriate and biocompatible option for the synthesis of these nanoparticles. Our research highlights the potential of employing bio-safe and eco-friendly AgNPs synthesized in the presence of S. tebesana Bunge extract, which possess remarkable antibacterial properties, for various biomedical applications