Mechanic of Advanced and Smart Materials

Abstract In this study, we combined the experimental work performed using a one-dimensional simulation program to simulate the capacity of a solar cell. Simulation can be used to show the real effects of a phenomenon on the target subject, under controlled and regulated conditions.In this here, CdTe based thin film solar cell has been investigated under AM 1.5 ghobal spectrum with using Solar Cell Capacitance Simulator-1D (SCAPS-1D) software. Initially, solar cells with nanostructured FTO/TiO2/n-CdSe/p-CdTe were considered as the elementary cells and FTO/ TiO2/n-CdSe/p- CdSe1_xTex/p-CdTe as the upgraded cells. The purpose of this study was to investigate the key role of layer CdSe xTe 1-x. The results of the analyzes showed that the presence of CdSe xTe1- x nanostructured layer, between p- type CdTe absorber layer and n- type CdSe layer increased PCE from 14.05% to 21.98%, JSC from 20.42. mA/ cm2 to 26.06 mA/cm2, FF from 54.73% to 57.69% and VOC from 1.25 V to 1.46 V compared to the elementary cell.

Abstract Water hardness refers to the total concentration of calcium (Ca2+) and magnesium (Mg2+), which is expressed in terms of the equivalent of calcium carbonate. Excessive amounts of Ca2+ and Mg2+ in water lead to serious consequences for home and industrial use. In this research, cellulose acetate (CA) was used to prepare polymer membranes used to remove calcium and magnesium ions. Graphene oxide (GO) and FeOOH nanoparticles were also added to the polymer solution to improve membrane performance to remove total water hardness. FTIR, SEM and XRD were also used for characterization of prepared nanostructures. The advantages of this research include the use of biocompatible polymer as well as proper membrane performance at low pressures (about 3 times) which saves energy compared to high pressure membrane processes such as reverse osmosis. The results showed that the addition of FeOOH nanoparticles and graphene oxide nano plates improved the performance of the prepared membranes.

Abstract Cyclones are devices used to separate two or more phases from each other. Cyclones are centrifugal particle collection systems that use the effect of a tornado to separate solid particles from the gas stream. The purpose of this article is to investigate the effect of 5 inlet parameters including inlet height, inlet width, outlet diameter, total cyclone height and body cyclone height on both pressure outlet and cut-off diameter. These parameters have not yet been investigated by Sobel analysis. In this article, the effect of 5 cyclone inlet parameters including inlet height, inlet width, outlet diameter, total cyclone height and cyclone body height on two outlet parameters including pressure drop and shear diameter was investigated through their regression equation and Sobel statistical sensitivity analysis. So far, the effect of these 5 parameters on these outputs has not been investigated through Sobel statistical sensitivity analysis. The results show that inlet width with 40%, inlet height with 36% and outlet diameter with 24% had the greatest effect on pressure drop, respectively, and the height of the cyclone and the square height of the body had no effect on pressure. On the other hand, the inlet height with 40%, the inlet height with 38%, the height of the cyclone with 12% and the body height of the cyclone with 10% have the greatest effect on the shear diameter, respectively, and the cyclone outlet diameter has no effect on the cut-off diameter.

Abstract Metamaterials are materials that exhibit unusual properties. Auxetic materials, as a class of metamaterials, are structures with a negative Poisson ratio. These materials become thicker when applied under tensile stress, unlike conventional materials, in the perpendicular direction to the applied force, and become thinner when applied under compressive stress. Auxetic behavior is an independent property that can be obtained from microscopic or macroscopic levels and even molecular or cellular levels. Many structures and materials are known of this feature. This unique feature has created potential applications in the military, aerospace, medical and intelligent sensors, and many other industries. However, there are still many problems with the widespread use of these structures. This paper provides a comprehensive review of these structures that have unique properties and applications of auxetic materials. In addition, some of the latest developments in these materials are described. Materials with a negative Poisson ratio have great potential in various applications such as lightweight structures or biomaterial applications.

Abstract Today, the corrosion of oil and gas supply and distribution lines is a major challenge in these industries. In order to prevent the corrosion of underground pipes, various types of coatings, especially bituminous base coatings, are used to protect oil and gas pipelines. One of the widely used tests for detecting defects in metal pipes of gas transmission lines is the magnetic flux leakage test method. This test is performed only on the metal pipe itself and determines the defects of the pipe. In this paper, the possibility of using this test to detect pipeline coating defects has been investigated. If the coating defects are detected, they can be prevented from spreading and reaching the metal body of the pipe. For this purpose, the magnetic flux leakage test of a part of a gas pipe with a coal-based bitumen coating along with a defect and with different thicknesses in the pipe and coating was simulated in Comsol software. The magnetic properties of the coatings were also extracted with a magnetometer. The results of the simulations showed that the leakage of magnetic flux in the coating defects is insignificant and cannot be measured to reveal the defects.

Abstract This research examines the vibrations of multi-layer aluminum-metal fiber cylindrical shells with embedded piezoelectric layers that have fluid-structure interaction based on the three-dimensional elasticity theory. Using the state space approach, the equations of motion for simple support boundary conditions were obtained. The natural frequencies of the multi-layer metal fiber cylindrical shell containing the driving fluid were obtained by solving the special frequency equation. The effect of different parameters such as length to radius, fluid velocity, ambient wave number and radius to thickness was investigated for aluminum reinforced with carbon fibers. The volume ratio of composite/metal was considered constant. So far, no research has been done on multi-layered aluminum fiber-metal cylindrical shells with embedded piezoelectric layers that have fluid-structure interaction. It is a very new topic. The consistency and convergence of the results of this research was confirmed by comparing the results of natural frequencies reported in the literature, and the high accuracy of the results of this research is expressed.

Abstract In this article, the free vibrations of non-uniform and non-homogeneous beams with the general non-classical boundary conditions including end objects with mass moment of inertia, eccentricity, and rotational and translational flexible constraints are investigated. A review of related beam sources shows that unlike many studies and various methods used to investigate the vibrations of non-uniform and non-homogeneous beams, the presented method often does not lead to a unique solution for the beam with the general boundary conditions. Hence presented solution cannot be used for the other special cases. Therefore, the purpose of this thesis is to present a new method based on the application of the Cauchy’s formula for iterated integrals which according to the best of author’s knowledge has not been considered so far. By using this method and its related equations, it is possible to analyze the vibrations of different types of homogeneous uniform, homogeneous non-uniform, functionally graded uniform, and functionally graded none-uniform beams. The validation of the obtained results for some of the studied configurations have been compared with the available data reported in related studies and good agreement observed. Also parametric study has been presented in order to investigate the effect of aspect ratio for wedge and tapered beams. To carry out convergence test and other calculations throughout this article a code in Mathematica software has been written.