Indian Institute of Technology Kharagpur

About: Indian Institute of Technology Kharagpur is a education organization based out in Kharagpur, India. It is known for research contribution in the topics: Natural rubber & Dielectric. The organization has 16887 authors who have published 38658 publications receiving 714526 citations.

HSAB principle applied to the time evolution of chemical reactions.

Abstract: Time evolution of various reactivity parameters such as electronegativity, hardness, and polarizability associated with a collision process between a proton and an X- atom/ion (X = He, Li+, Be2+, B3+, C4+) in its ground (1S) and excited(1P,1D,1F) electronic states as well as various complexions of a two-state ensemble is studied using time-dependent and excited-state density functional theory. This collision process may be considered to be a model mimicking the actual chemical reaction between an X-atom/ion and a proton to give rise to an XH+ molecule. A favorable dynamical process is characterized by maximum hardness and minimum polarizability values according to the dynamical variants of the principles of maximum hardness and minimum polarizability. An electronic excitation or an increase in the excited-state contribution in a two-state ensemble makes the system softer and more polarizable, and the proton, being a hard acid, gradually prefers less to interact with X as has been discerned through the dro...

Fast efficiency optimization techniques for the indirect vector-controlled induction motor drives

Abstract: This paper presents two simple and very useful techniques for the efficiency optimization of the indirect vector-controlled induction motor drives. In the synchronously rotating reference frame the flux-producing current is controlled until the power at the DC link is minimum. Of the two techniques, the first method controls the flux-producing current in a regular and smooth manner. The second technique combines loss model and search approaches in a unique way to propose a hybrid method, where the first estimate is from the loss model approach and the subsequent adjustment of the flux is through the search technique. Both the algorithms are simple, easily realizable, and offer fast convergence. Also, smooth control of the flux offers excellent dynamic performance. A comparative assessment shows that the hybrid method is the best, even if an approximate equivalent circuit for the induction motor is used for the analysis and optimization of the losses. The close agreement between the simulation and the experimental results confirms the validity and usefulness of the proposed techniques.

A thermo-electric model of material removal during electric discharge machining

Abstract: In Electro Discharge Machining (EDM), melting is the main process for metal removal. However, for short pulses (discharge duration 100 μs), this electrostatic force becomes very small and does not play a significant role in the removal of metal. In the model proposed, the electrostatic force acting on the metal surface and the stress distribution inside the metal due to this electrostatic force have been estimated. The variation of the yield strength with depth inside the metal has also been found out and finally the 'crater depth' due to this electrostatic force has been calculated.

Stylometric Analysis of Bloggers’ Age and Gender

Abstract: We report results of stylometric differences in blogging for gender and age group variation. The results are based on two mutually independent features. The first feature is the use of slang words which is a new concept proposed by us for Stylometric study of bloggers. Slang is a non-dictionary word that has evolved with time due to its frequent and popular usage. For the second feature, we have analysed the variation in average length of sentences across various age groups and gender. These two features are then augmented with previous study results reported in literature for stylometric analysis of age and gender. The combined feature list enhances the accuracy by a remarkable extent in predicting age and gender. These experiments were done on a 20,000 blog corpus. Experimental results show that these features work well in detection of bloggers’ demography. However, gender determination is more accurate than age group detection over a data spread across all ages but the accuracy of age prediction increases if we sample data with remarkable age difference.