For more than a decade, externally bonded carbon fiber reinforced polymer (CFRP) composites successfully utilized in retrofitting reinforced concrete structural elements. The function of CFRP reinforcement in increasing the ductility of reinforced concrete (RC) beam is essential in such members. Flexural and shear behaviors, ductility, and confinement were the main studied properties that used the CFRP as a strengthening material. However, limited attention has been paid to investigate the energy absorption of torsion strengthening of concrete members, especially two-span concrete beams. Hence, the target of this work is to investigate the effectiveness of CFRP-strengthening technique with regard to energy absorption of two-span RC

This paper is focused on orthogonal function approximation technique FAT-based adaptive backstepping control of a geared DC motor coupled with a rotational mechanical component. It is assumed that all parameters of the actuator are unknown including the torque-current constant (i.e., unknown input coefficient) and hence a control system with three motor control modes is proposed: 1) motor torque control mode, 2) motor current control mode, and 3) motor voltage control mode. The proposed control algorithm is a powerful tool to control a dynamic system with an unknown input coefficient. Each uncertain parameter/term is represented by a linear combination of weighting and orthogonal basis function vectors. Chebyshev polynomial is used

This study aims to evaluate the adsorption isotherm of carbon microparticles prepared from pumpkin (Cucurbita maxima) seeds for adsorbing curcumin (as a model of dye). The results were derived and compared using the kinetics approach based on several standard adsorption isotherm models, namely the Langmuir, Temkin, Freundlich, and Dubinin-Radushkevich models. The second aim is to evaluate the effects of carbon particle size (from 100 to 1000 mm) on the adsorption characteristics. The experimental results showed that the adsorption on the surface of carbon microparticles occurred in monolayer with a physical phenomenon. This is because the active areas are located only on the outer surface of carbon and no surface structure in th

     Dental amalgam is a mixture of approximately 50% mercury and varying ratios of silver, tin, zinc, and copper. Dental amalgam is a major source of mercury pollution because it is readily absorbed through 90-100% vapour and the oral mucosa. In addition, in certain situations with the oral environment, various types of metallic orthodontic brackets are highly aggressive and can lead to corrosion. However, polyvinyl alcohol (PVA) material has no cytogenetic effects on human health or the environment and is therefore applied in the manufacturing of the new composite material. Different additives from the bonding agent (PVA; 2.4, 4.8, and 7.2 g)  dissolved in about 10 ml of water, heated on a hot plate under a hig

         The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Resu

   In this study, titanium dioxide (TiO₂ (are synthesized by sol– gel simple method. Thin films of sol, gel, and sol- gel on relatively flat glass substrates are applied with Spin coating technique with multilayers. The optical and morphological properties (studied using AFM) of TiO₂ layers show good properties, with particles diameters less than 4 nm for all prepared samples and have maximum length 62 nm for TiO₂ gel thin films of three layers. The results show low roughness values for all films especially for 4 layers sol (8.37nm), which improve the application in dye sensitive solar cell (DSSc)         .