pH SENSOR The final control element can be a pump or an ON/OFF valve. Sizing of the final control element is complicated and depends on many factors. This is one situation where a titration curve can be invaluable. In many cases, it may be necessary to use two final control elements, each delivering different amounts of chemical and having different setpoints. For example, one valve may deliver...

In this paper, the improved  -expansion method is proposed to solve the Kundu–Eckhaus equation and Gerdjikov–Ivanov model. The applied method are analytical methods to obtaining the exact solutions of nonlinear equations. Here, the aforementioned methods are used for constructing the soliton, periodic, rational, singular and solitary wave solutions for solving some equations. We obtained furthe...