Development of a green corrosion inhibitor for use in acid cleaning of MSF desalination plan

A green and cost-effective inhibitor based on Date palm leaves extract was formulated for use during acid cleaning of thermal desalination plants. The inhibitor formulation designated as F1 was tested against the corrosion of ferrous-based alloys namely: carbon steel, Ni-resist, and 316L stainless steel in 2% HCl solution at 40 °C under static and hydrodynamic conditions. Weight loss and electrochemical methods complemented with scanning electron microscopy were used in the study. Experiments were performed for 6, 24, and 72 h and the performance of F1 was compared with that of a commercial acid corrosion inhibitor. F1 exhibited excellent corrosion inhibition performance. Under static and dynamic conditions, 0.4% of F1 provided excellent corrosion inhibition up to 72 h and comparable to the commercial inhibitor performance. The inhibitors (F1 and the commercial one) exhibited a behavior typical of a mixed type corrosion inhibitor in the studied environment according to the potentiodynamic polarization. Results from cyclic potentiodynamic polarization experiments excluded pitting corrosion risk on the 316L stainless steel in the studied medium. Results from all applied techniques are in good agreement

Dynamic replication strategies in data grid systems: A survey

In data grid systems, data replication aims to increase availability, fault tolerance, load balancing and scalability while reducing bandwidth consumption, and job execution time. Several classification schemes for data replication were proposed in the literature, (i) static vs. dynamic, (ii) centralized vs. decentralized, (iii) push vs. pull, and (iv) objective function based. Dynamic data replication is a form of data replication that is performed with respect to the changing conditions of the grid environment. In this paper, we present a survey of recent dynamic data replication strategies. We study and classify these strategies by taking the target data grid architecture as the sole classifier. We discuss the key points of the studied strategies and provide feature comparison of them according to important metrics. Furthermore, the impact of data grid architecture on dynamic replication performance is investigated in a simulation study. Finally, some important issues and open research problems in the area are pointed out

Torque and stator flux ripples minimization for direct torque control of PMSM by using space vector modulation

International audienceIn this article, we present the strategy of the direct Torque control (DTC) of the permanent magnets synchronous machine (PMSM) with regulators in hysteretic controlled by the technique SVM: Space Vector Modulation that use the hysteresis comparator for the determination the voltage module and its angle. This method of control allows reducing the fluctuations at the level of the torque and of the flux also in the low speed contrary with control of the classical DTC where the frequency of switching is incontrollable. Simulations results obtained allow demonstrate the performances of this command especially in the behavior of the couple and the flux

Torque and stator flux ripples minimization for direct torque control of PMSM by using space vector modulation

International audienceIn this article, we present the strategy of the direct Torque control (DTC) of the permanent magnets synchronous machine (PMSM) with regulators in hysteretic controlled by the technique SVM: Space Vector Modulation that use the hysteresis comparator for the determination the voltage module and its angle. This method of control allows reducing the fluctuations at the level of the torque and of the flux also in the low speed contrary with control of the classical DTC where the frequency of switching is incontrollable. Simulations results obtained allow demonstrate the performances of this command especially in the behavior of the couple and the flux