Al-Nahrain Journal for Engineering Sciences

The intention of this study is to explore the efficiency and feasibility of adsorption of Reactive Blue dye (H3R) used in textile industries using Raw wheat straw (RWS) and Modified wheat straw (MWS) as a low-cost adsorbent. Wheat straw was modified using cationic surfactant (CTAB) to study the improvement of dye removal. The properties of Raw and Modified wheat straw are studied by means of Fourier transform infrared (FTIR) and scanning electron microscope (SEM) analysis to determine the functional groups and the nature of their surface. Continuous experiments were conducted by fixed-bed column to study the characteristics of the breakthrough curve using different bed heights and flow rates. Results showed that the breakthrough time increases with the increase of bed height and flow rate, which in turn result in higher removal capacity. Results also showed that a higher flow rate leads to a lower adsorption capacity due to insufficient residence time. Bed depth service time model (BDST), Adam-Bohart and Thomas models were used to predict the breakthrough curves and to determine the adsorption capacity of the column. The highest bed capacity of 12.95 and 32.2 mg/g for MWS were obtained using 10 mg/L, 10 cm bed height at 10 mL/min and 30 mL/min respectively.

The aim of this work is to optimize EPD variables (voltage, time, and focus) using alternating current through the Taguchi Design of Experiment (DOE). Coating Nano hydroxyapatite (Nano-HA) on a Ti6Al4V substrate depends on thickness and roughness, then characterization of a coating layer to determine the optimum state. Hydroxyapatite (HAp) powder was deposited on a Ti-6Al-4V alloy substrate by electro-deposition with ethanol as a solvent under AC current, to improve the alloy surface quality based on coating thickness and maximum coating mass meeting the requirements of a biological orthopedics application. Ethanol was used as a solvent to precipitate ketazone and HAp on the base alloy. Taguchi's approach was used in order to determine the optimal conditions for EPD and subsequently to apply various criteria for depositing the biochemical coating. The surface and cross-section composition of the paint is described by characterization. Numerous tests and inspections; Zeta, XRD and SEM stability test, water contact angle and optical microscopes were used to describe the surface morphology of the HAp layer. The value of the optimum conditions for deposition of the HAp layer which is a simultaneous thickness and maximum coating mass, was predicted at a sedimentation voltage of 40 V, 2 min sedimentation time and 1 g / L for the concentration of the suspended solution at room temperature. The validity of the model resulting from the response surface methodology was assessed by comparing the expected results with the experimental results. In addition, close agreement was observed between the experimental results and the expected results. For the solution at room temperature, the results obtained with the highest value of the coating thickness of 41at the surface roughness of 0.94 and the contact angle of the alloy before coating is 67.489º reduced to. 38.132º after plating, which indicates an increase in the harmony of the metal implant and biocompatibility.

The traditional finishing method cannot keep up with recent labor market requirements, solve the problem of increasing production, improve the surface roughness and accuracy of workpiece. While the unconventional magnetic abrasive finishing (MAF) method has shown as a promising technique that can be used to finish complicated surfaces. MAF finishes metals, alloy, ceramic, and other materials that are difficult to finish by other processes. In another word, MAF improves the quality of surfaces with low cost.
This paper focuses on optimize and study the effect of inductor and pole geometry (radius of hole, angle of core, angle of pole, radius of pole), on (surface roughness (Ra) and material removal weight (W)) and fined the optimum values that increase the efficiency of MAF method. Taguchi method employed to study the influence of geometry parameters and find the optimum values using orthogonal array L9. The results conclude that the most significant factor that effects change in surface roughness (ΔRa) and material removal weight(ΔW) are radius of the hole (R) and angle of core (α), respectively.

In the present work the effect of Corrosion & Scale Inhibitor was evaluated by using of the commercial product (Kurita S2050) that mainly containing of (Na2HPO4) sodium phosphate as corrosion inhibitor and (C6H11NaO7) sodium glocunate as scale inhibitor & dispersant. The dosing rate of this chemical was controlled according to the treatment system depend mainly on the monitoring of LI & RI indexes for (30) days treatment in the cooling tower unit of Al-Dora Oil refinery-Baghdad. The corrosion rate and the corrosion inhibitors efficiency were calculated by measurement of weight loss in standard test coupon (AISI 1010). After 30 day of the Field Test, the result show that the treatment program performance was effective in the corrosion & scale inhibition through an acceptable corrosion rate less than 0.018 in gmd. Also the result of corrosion rate was analyzed statistically by using of (ANN) to formulate a prediction equation to corrosion rate identification.

A new robust control algorithm is proposed for a class of nonlinear systems represented by a Single Link Manipulator (SLM) system. This algorithm is based on new techniques and methods in order to obtain a controller for the SLM system. First of all, the system is simplified using Variable Transformation Technique (VTT) in order to fit the analysis procedure. Then, a new idea of designing a model reference for the multiple states (n=4) system is presented to correspond the control design. Next, the Lyapunov Stability Analysis (LSA) is used to figure out a proper controller that can compensate the stability and the performance of the SLM system. After that, the Most Valuable Player Algorithm (MVPA) is applied to find the optimal parameters of the proposed controller to accomplish the optimum performance improvement. Finally, it can be concluded that the proposed control algorithm has improved the stability and the performance of the SLM system. In addition, the simulation results show the remarkable effects of the proposed nonlinear controller on the SLM system.

The main purpose of this paper is to design a robust second order sliding mode controller that can deal with uncertain nonlinear systems. This controller can keep the main advantages of the first order sliding mode controller, such as the ability to make the system asymptotically stable by forcing the error and its derivatives to have a zero value, the simplicity in the operation, and the robustness in the existence of perturbations. In spite of the features that characterize the first order sliding mode controller (1 SMC), it still suffers from the unwanted phenomenon “chattering”, which originates from a discontinuous control part (sign function). In this context, saturation function can be used instead of sign function to reduce this problematic chattering. Different from the saturation function method, the second order sliding mode controller can be used to overcome the chattering; suffered by the first order sliding mode controller and to retain the stability and performance of the system. In this paper, the twisting and the super twisting second-order algorithms of the sliding mode controller were used, and their results were compared with the first order sliding mode controller. So, this subject focused on the chattering problem who suffers from it the 1 SMC and try to reduce it by using the 2 SMC, the uncertain pendulum system was adopted in this work for the purpose of checking the three controllers. The simulations results showed that the second order sliding mode controller has the ability to reduce both the chattering magnitude and the steady state error and achieve an asymptotically stable system. The results were obtained by using MATLAB programming.

In this study, previous researches were reviewed in relation to the seismic evaluation and retrofitting of an existing building. In recent years, a considerable number of researches has been undertaken to determine the performance of buildings during the seismic events. Performance based seismic design is a modern approach to earthquake resistant design of reinforcement concrete buildings. Performance based design of building structures requires rigorous non-linear static analysis. In general, nonlinear static analysis or pushover analysis was conducted as an efficient instrument for performance-based design. Pushover analysis came into practice after 1970 year. During the seismic event, a nonlinear static analysis or pushover analysis is used to analyze building under gravity loads and monotonically increasing lateral forces. These building were evaluated until a target displacement reached. Pushover analysis provides a better understanding of buildings seismic performance, also it traces the progression of damage and failure of structural components of buildings.