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

A direct power control of the doubly-fed induction generator based on the SVM Strategy

This paper proposes a direct power control scheme for the doubly-fed induction generator (DFIG) for variable speed wind-power generation. The machine is connected as a generator. Its rotor is fed by a two-level inverter. We propose to control the DFIG with a technique based on the direct power control (DPC) performances. A combination of a space-vector modulation (SVM) technique and active and reactive power controllers is made to replace hysteresis controllers used in the classic DPC drive resulting in a fixed switching frequency of the power converter. The performances obtained by using this control strategy are shown under MATLAB Simulink