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The main emphasis of this paper is placed on the effectiveness of the proposed optimization method in material identification. The primary motivation of integrating GA, ACO and PSO is to minimize each other’s weaknesses and to promote respective strengths. In the proposed algorithm, the effect of random initialization of GA is subdued by passing the products of GA through the ACO and PSO operators to well organize the exploitative and exploratory search coverage. In return, GA improves the convergence rate and alleviates the strong dependency on the pheromone array in ACO as well as resolves the conflict arisen in identifying the trade-off parameter and further refine the exploitative search of PSO with the introduction of two-point standard mutation and one-point refined mutation. The proposed algorithm has been verified and applied in composite material identification with absolute percentage errors between measured and evaluated natural frequencies not more than 2%. [ABSTRACT FROM AUTHOR]

Destructive identification approaches are no longer in favor since the advent of nondestructive evaluation approaches, as they are accurate, rapid, and cheap. Researchers are devoted to improving the accuracy, rate of convergence, and cost of such approaches, which depend greatly on the types of vibrational experiments conducted and the types of forward and inverse methods used in numerical section. Therefore, this article presents a review on the development of nondestructive vibrational evaluation approaches in identifying the elastic constants of composite plates, in experimental and numerical manners in order to enlighten researchers with the current trends of nondestructive vibrational approaches. [ABSTRACT FROM PUBLISHER]

Many applications consider Polypyrrole (PPy) one of the most prominent conductive polymers due to its distinguished character, low cost, and easy preparation. Recently, organic polymeric conductors have seen an upsurge in photocatalysts for energy conversion, and air/water depollution under either UV and/or visible light illumination. We present a comprehensive review of related papers for PPy in water/air pollutant photodegradation, CO 2 reduction reaction (CO 2 RR), or evolution of hydrogen from water dissociation (WSP) under simulated sunlight irradiation, mainly in the last ten years. Besides, some of the current applications for PPy as pure or a portion of composite material are also included briefly. This review also includes the synthesis strategies, polymerization process parameters, modification methods, photocatalytic activity, and challenges that face PPy-based materials. Above and over, the main difficulties and prospects of using PPy-based photocatalytic material in the perspective application have also been mentioned. [Display omitted] • The synthesis and applications of polymeric-based semiconductive. • The role of PPy in enhancing the performance of semiconductive material as a photocatalyst. • The impact synthesis route on the performance and character of prepared material. [ABSTRACT FROM AUTHOR]

In this study, maghemite/PMMA nano-fibrous composites have been successfully fabricated by using the electrospinning process. PMMA nano-fibres have been selected to be used as the matrix; the PMMA was dissolved in three diverse solvents (Acetone, THF and DMF) in order to obtain fine PMMA nano-fibres. As a result, the PMMA–DMF proved to be the most appropriate polymer solution among the three solvents, with its impressive defect-free surface morphology results. The production of maghemite using Massart’s procedure resulted in nano-particles with an average diameter of 4.98 ± 0.13 nm (using transmission electron microscopy (TEM)). Maghemite nano-particle were then mixed with a prepared polymer solution in order to fabricate maghemite/PMMA nano-fibrous composite. Furthermore, the investigation of the morphology and structure of the composite was carried out using field emission scanning electron microscopy (FESEM), Energy-dispersion X-ray spectroscopy (EDX), Alternating Gradient Magnetometer (AGM), Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD) and tensile strength measurement devices. The results indicated that there was a great amount of maghemite, both in and on the composite’s surface, which can be utilized in the purpose of magnetic applications. [ABSTRACT FROM AUTHOR]

The chitosan/polyvinyl Alcohol/zeolite electrospun composite nanofibrous membrane was fabricated for adsorption of methyl orange. The EDX, TGA and tensile test were carried out for the characterization of the membrane. The Young’s Modulus of the nanofibrous membranes increased by more than 100% with the addition of zeolite to chitosan/PVA. The batch adsorption tests were conducted by varying the initial concentration of methyl orange, contact time and pH of the dye solution. UV–vis results showed that most of the dye was adsorbed within 6 min. An adsorption kinetic study was carried out using the pseudo-second-order kinetic model, Lagergren-first-order model and intra particle diffusion model. The adsorption kinetics obeyed the Pseudo second order model. The adsorption mechanism was analyzed using the Langmuir and Freundlich isotherm model. The experimental data fits well with the Freundlich model. The adsorption capacity of the membrane was 153 mg/g. Adsorption capacity was decreased with increasing pH value. The resulting nanofiber became less active over methyl orange after several runs. [ABSTRACT FROM AUTHOR]