Shiv Nadar University

About: Shiv Nadar University is a education organization based out in Dadri, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Graphene. The organization has 1015 authors who have published 1924 publications receiving 18420 citations.

Metal-free C(sp2)-H functionalization of azoles: K2CO3/I2-mediated oxidation, imination, and amination.

Abstract: The direct C2−H oxidation and imination of a wide variety of azoles was achieved by using a commercially available simple K2CO3/I2 reagent combination. The iodinated azole adduct, produced via the in situ generation of N-heterocyclic carbene, is the key intermediate for C2−H oxidation, imination, and amination of azoles. Significantly, these reactions proceed under mild conditions with high to excellent yields, are scalable to large quantity and exhibit a broad substrate scope. Interestingly, this direct C2−H imination method allowed us to access various pharmacologically active N6-alkyl or N6-aryl substituted benzimidazoquinazolinone scaffolds through intramolecular C−H imination in a sequential one-pot reaction.

Crack interaction study in piezoelectric materials under thermo-electro-mechanical loading environment

Abstract: Multiple voids and cracks were generated during material processing techniques, which interact with each other and affects the service performance of piezoelectric components. This work aims to study the behavior of piezoelectric components in presence of multiple cracks under thermo-electro-mechanical loading environment. Extended finite element method has been implemented to model geometrical discontinuities with crack interaction phenomenon. In this work, thermo-electro- mechanical problem has been decoupled into thermal and electro-elastic problems. Temperature distribution has been obtained by solving heat conduction equation and then used as an input to the electro-elastic problem. In post processing phase, interaction integral method and generalized Stroh formalism were used to predict the stress intensity factors. The methodology has been implemented with in-house developed MATLAB code. Set of cases for crack interaction studies were presented using the proposed approach.

Unravelling oxygen driven α to β phase transformation in tungsten.

Abstract: Thin films of β-W are the most interesting for manipulating magnetic moments using spin-orbit torques, and a clear understanding of α to β phase transition in W by doping impurity, especially oxygen, is needed. Here we present a combined experimental and theoretical study using grazing incidence X-ray diffraction, photoelectron spectroscopy, electron microscopy, and ab initio calculations to explore atomic structure, bonding, and oxygen content for understanding the formation of β-W. It is found that the W films on SiO2/Si have 13-22 at.% oxygen in A15 β structure. Ab initio calculations show higher solution energy of oxygen in β-W, and a tendency to transform locally from α to β phase with increasing oxygen concentration. X-ray absorption spectroscopy also revealed local geometry of oxygen in β-W, in agreement with the simulated one. These results offer an opportunity for a fundamental understanding of the structural transition in α-W and further development of β-W phase for device applications.

In silico modeling for quick prediction of inhibitory activity against 3CLpro enzyme in SARS CoV diseases

Abstract: As of 2 September 2020, the 2019 novel coronavirus or SARS CoV-2 has been responsible for more than 2,56,02,665 infections and 8,52,768 deaths worldwide. There has been an urgent need of newer drug discovery to tackle the situation. Severe acute respiratory syndrome-associated coronavirus 3C-like protease (or 3CLpro) is a potential target as anti-SARS agents as it plays a vital role in the viral life cycle. This study aims at developing a quantitative structure-activity relationship (QSAR) model against a group of 3CLpro inhibitors to study their structural requirements for their inhibitory activity. Further, molecular docking studies were carried out which helped in the justification of the QSAR findings. Moreover, molecular dynamics simulation study was performed for selected compounds to check the stability of interactions as suggested by the docking analysis. The current QSAR model was further used in the prediction and screening of large databases within a short time.Communicated by Ramaswamy H. Sarma.

Off-Farm Labor Supply and Correlated Shocks: New Theoretical Insights and Evidence from Malawi

Abstract: We offer new conceptual insights into the understanding of occupational choice in uncertain rural environments, with a focus on its ex ante (before a shock) and ex post (after a shock) consequences for farmers belonging to different portions of the asset distribution. We model theoretically the choice between relatively safe subsistence farming, higher return but higher risk cash crop activities, and off-farm labor—conditional on preexisting asset allocation—and look at the general equilibrium labor market implications of correlated shocks. Our results, backed by evidence from Malawi, challenge some stylized perceptions in the literature on consumption smoothing via off-farm labor supply.