Simulation and Comparison of Three and Nine level Cascaded H-bridge Multilevel Inverter

The multilevel inverter was developed as a solution to increase the converter operating voltage above the voltage limits of classical semiconductors. The function of the multilevel inverter is to synthesize a high voltage waveform from several lower levels of dc voltages. If the switching angle arrangement technique is not selected properly then the total harmonic distortion of voltage output waveform may become unacceptable. In this paper the sinusoidal pulse width modulation (SPWM) control strategy is used to control output voltage. In this paper simulation of single phase three and nine level cascaded H-bridge multilevel inverter is performed in Simulink environment. The comparison of THD values of these inverters is done

Efficient removal of Cr (VI) from aqueous solution by using tannery by-product (Buffing Dust)

The current study is focused on using tannery waste called buffing dust to remove hexavalent chromium from an aqueous solution. The buffing dust was characterised by using different technique like FTIR, SEM, and BET analysis. The adsorption experiment was conducted in batch mode. The different operating factors including contact time, dose and initial Cr (VI) concentration were investigated. The optimum adsorption capacity was observed at contact time of 240 min and dose of 1g/100 mL. The adsorption isotherm such as Langmuir, Freundlich and Temkin were investigated at different initial concentration. It was observed that Langmuir isotherm model was best fitted for present study with maximum adsorption efficiency of 11.33 mg/g. The kinetic study was performed for pseudo first order and pseudo second order and it was found that pseudo second order model was provided the best match with regression coefficient (R2) of 0.9991