Motilal Nehru National Institute of Technology Allahabad

About: Motilal Nehru National Institute of Technology Allahabad is a education organization based out in Allahabad, Uttar Pradesh, India. It is known for research contribution in the topics: Control theory & Electric power system. The organization has 2475 authors who have published 5067 publications receiving 61891 citations. The organization is also known as: NIT Allahabad & Motilal Nehru Regional Engineering College.

Modeling and optimization of geometrical characteristics in laser trepan drilling of titanium alloy

Abstract: Laser drilling has become an alternative to drilling precise holes in advanced difficult-to-cut superalloys. Due to better hole quality and capability to generate macro-size holes, laser trepan drilling is becoming more popular as compared with laser percussion drilling. This paper presents a study of laser trepan drilling process performance in terms of geometrical quality characteristics, such as hole taper and circularity for drilling small diameter hole in difficult-to-cut Titanium alloy sheet. Due to involvement of different process parameters such as laser power, pulse width, pulse frequency, workpiece thickness, material composition, cutting speed, stand of distance and assist gas pressure, the laser cutting is a highly nonlinear and complex process. To handle this nonlinearity and complexity, genetic algorithm has been applied for the optimization. We used assist gas pressure, pulse width, pulse frequency and trepanning speed as input process parameters. The effect of significant process parameters on hole characteristics are discussed on the basis of data obtained through a well designed orthogonal array experimental matrix. Reliable empirical models have been developed for different quality characteristics. Improvements of 49% and 8% have been registered in hole taper and circularity, respectively, at optimum level of process parameters.

Equilibrium Study on the Extraction of Levulinic Acid from Aqueous Solution with Aliquat 336 Dissolved in Different Diluents: Solvent’s Polarity Effect and Column Design

Abstract: In the present study, the reactive extraction of levulinic acid (4-oxopentanoic acid) was investigated by using Aliquat 336 in various organic solvents [benzene, dichloromethane (DCM), dodecane, methyl isobutyl ketone (MIBK), 1-octanol] from dilute aqueous solution. Equilibrium data obtained at 298 K and 101.325 kPa were used to determine the values of distribution coefficient (KD), degree of extraction (E%), loading factor (Z), and complexation constants (KE). Among the diluents tested, DCM gave the highest extraction efficiency. Using 0.5454 mol·kg–1 of Aliquat 336 in DCM, KD and E% were obtained as 2.082 and 67.55%, respectively, at 0.2795 mol·kg–1 initial acid concentration in the aqueous solution. Z values were found to be between 0.033 and 1.628 depending on the nature of the diluent used and Aliquat 336 concentration in the organic phase. Using mass action law modeling, the stoichiometry of the extraction reaction was determined. It was observed that mostly 1:1, 2:1, and 3:1 types of complexes were...

Novel way for classification and type detection of voltage sag

Abstract: This study presents a new classification of voltage sags which is based on its types, characteristic voltage and zero-sequence component of voltage. It is extremely difficult to distinguish between the voltage sags which have same type, same characteristic voltage and same zero-sequence component of voltage due to load effects and hence such classification is significant. The proposed classification is mathematically justified by introducing two new indices, namely, phase-to-neutral and phase-to-phase voltage indices. Using the theoretical relation between these two indices, it has been revealed that the voltage sags which have the same type, same characteristic voltage and same zero-sequence component of voltages, have same mathematical relations. Further, to reveal the accuracy of the proposed classification and type detection, it is validated through recorded waveforms available in IEEE database, Scottish Power, data obtained from Matlab simulation under different conditions of voltage sags and data of real power station. In addition, the proposed classification and type detection are compared with other established algorithms for type detection of voltage sags. The comparative results show that the proposed classification not only removes the existing anomalies in the earlier proposals but also shows its superiority by presenting more accurate and less confusing results.