A robot must employ a suitable control method to obtain a good stability. The Two-Wheeled Self Balancing Robot in this paper is designed using a MPU-6050 IMU sensor module and ATmega128 microcontroller as its controller board. This IMU sensor module is employed to measure any change in the robot's tilt angle based on gyroscope and accelerometer readings contained in the module. The tilt angle readings are then utilized as the setpoint on the control methods, namely PD (Proportional Derivative), PI (Proportional Integral), or PID (Proportional Integral Derivative). Based on the conducted testing results, the PID controller is the best control strategy when compared to the PD and PI control. With parameters of Kp = 14, Ki = 0005 and Kd = 0.1, the robot is able to adjust the speed and direction of DC motor rotation to maintain upright positions on flat surfaces.

Water is a basic human need in everyday life. However in some areas consumable clean water is still unattainable. There is an urgent need for water purification equipment. Several researches on water purification devices has been carried out with different methods. One of the methods amongst them is using the Dielectric Barrier Discharge Reactors. This method applies appropriate temperatures to make it safe for use. This paper discusses about the various methods used in water purification. The previous researchers discussed a lot about the parameters of the ozone producing capability. They also explained the characteristics and effects of voltage related to voltage sources. Furthermore, the factor of non-potable water is also used as a research material. Based on these previous researches, the researcher reviewed and investigated two of the types of electrodes used - The screw and helix type. They were examined in the same reactor tube length, thickness and tube material dimensions.

Ozone generation using screw-type electrodes with different distance peak to peak was studied, with the view to comparing the effectiveness of the two technologies in improving for high ozone concentration. Current density, heat flux, and distribution electric potential were performed by using simulation software Ansys. These simulations indicate that the screw-type electrode with a distance of 2 mm generates the higher current density, the result is the same as the initial assumption that the screw distance 2 mm will be better than distance 1.5 mm because it has lower heat flux. Experimental work confirms that a screw model with a distance of 2 mm also has high ozone concentration than a distance 1.5 mm screw model due to current density making electric field strength also higher to produce high ozone concentration, as was also noted by previous authors.

No abstract