Abstract:The detection of Leptospira bacteria in water using polyaniline (PANI) nanocomposites thin films doped with Fe-Co via sol-gel method is investigated in this research. In this study, the relationship between Leptospira bacteria concentration to current was measured based on current-voltage (I-V) performance. The morphologies of the thin film are characterized using FESEM, TEM and AFM. Based on the results, the developed nanocomposite thin films are compatible to detect the presence of pathogenic Leptospira bacteria. FESEM shows the irregularity of nanoparticles in terms of substrate size which was in the range of 80 nm to 120 nm. AFM image provided a specific morphology structure for Leptospira detection. Precisely, the PANI-Fe0.4-Co0.6 nanocomposite thin film has shown higher sensitivity towards pathogenic Leptospira detection. These results reaffirmed the potentials of Polyaniline-Fe- Co nanocomposite thin films for pathogenic Leptospira bacteria detection in water.

Keywords:Pathogenic Leptospira; Polyaniline; I-V measurement; Thin Film.

Abstract:The purpose of the paper is to manipulate the separately excited DC motor via the usage of the strength electronic IGBT (Insulate Gate Bipolar Transistor). The speed of separately excited DC motor may be manipulated by using varying the armature terminal voltage. In this way the speed may be controlled for above rated speed and under the rated speed respectively. In this model, the speed of motor up to and below the rated speed may be achieved via changing the armature voltage. The voltage of armature terminal may be precise by using IGBT or MOSFET established chopper. The IGBT chopper get the signal from controller and adjustable voltage is given to the armature of dc motor according to the specified speed. The main benefits to apply this method is that the speed varies proportionally with armature terminal voltage and varies inversely with subject terminal voltage with the help of maintaining the voltage of discipline and armature steady respectively. The PI controller is finding for isolation of delay and presents very fast manage. The version of one after the other excited DC motor is designed and the general format of DC force mechanism is obtained. By the assessment of triangular carrier signal with reference signal we get the PWM pulse for chopper switch. The simulation version is designed within the MATLAB/SIMULINK. The simulation output parameters of simulation model of DC motor such as; armature current, armature voltage, torque, speed, field current is analyzed.

Keywords:Armature Voltage control, DC/DC Buck converter, Proportional Integral (PI) controller. PWM generator, separately excited DC motor.