Power Plant Heat exchanger is widely used in chemical and petroleum plants because it can sustain wide range of temperature and pressure. Heat exchanger is a high nonlinearity and poor dynamics plant; therefore it is complex to model and difficult to control its dynamics. In this paper two types of heat exchanger model and controller are applied for selecting suitable model and controller. First model is called (Physical model) and derived using real parameter of heat exchanger plant. Second, a Second Order Plus Dead Time (SOPDT model) that is derived from the response of heat exchanger. While the controllers are consisted of fuzzy proportional derivative (FPD) controller and proportional integral derivative (PID) controller and applied to the model and their responses are compared with the existing PID controller. The PID controller response based on Physical model gives similar response of existing PID controller based real heat exchanger plant in comparison with SOPDT model. That means the Physical model is able to represent the heat exchanger plant dynamics more accurately than SOPDT model. For the controller, the FPD control gives a slight enhancement based on SOPDT model. Therefore, FPD controller is more suitable than PID controller.

Diapers have been popular with parents for a past few decades now for protecting babies/children from urine when they urinate. However, there are some disadvantages when using diapers such as skin rash, irritation, and infection. Skin rashes can occur when the diaper is wet with urine and left to be used for a long time with the baby. This paper aims (i) to develop wet diaper detection and notification device for helping caretakers identify wet diaper conditions, (ii) to evaluate the performance of the wet diaper detection and notification device based on the response time to trigger notification after detecting wet diaper condition. The methods of this study were divided into four phases including project design, algorithm development, hardware development, and performance evaluation. This system serves to identify the wet diaper condition based on temperature and humidity values. DHT22 was selected as a main sensor and Arduino pro mini was selected as the microprocessor for this project. As the results, two wet diaper detection and notification devices have been designed and fabricated. Comparisons have been made to evaluate the performance between the first and second versions of the devices. The performance of second version device resulting better response time with 1700ms to notify the caretaker when detecting the wet diaper condition.