2. The fermentation reactor shown below is very sensitive to the pH. Thus, there are two control loops (labeled "1" and "2") to control the pH. The nutrient solution is naturally acidic, but if it is too acidic, then a basic buffer is added (via loop 1). Also, if the solution in the tank becomes too acidic, then a basic buffer can be added (via loop 2). The worst-case scenario is if the solution in the reactor becomes too acidic. Based on this scenario, answer the following questions. pH measured Nutrient Solution T Caustic (basic) buffer fermentation pH measured product a) What is the gain between the caustic flowrate and the pH of the tank? Circle: Positive Negative Neutral b) What is the gain between the nutrient flowrate and the pH of the tank? Circle: Positive Negative Neutral c) Should the valve be designed as air-to-open or air-to-close? Circle: air-to-open air-to-close d) Is control loop #1 feedforward or feedback? Circle: Feedforward Feedback e) Is control loop #2 feedforward or feedback? Circle: Feedforward Feedback f) What is the gain between the caustic flowrate and the volume of liquid in the tank? Circle: Positive Negative Neutral