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.

Experimental study on bursting events around a bar in physical model of a braided channel

Abstract: Sediment particles entrainment from the channel bed is influenced by flow turbulence which creates fluctuating shear stress at the bed. Sweep quadrant event is considered to be most important for entrainment of sediment particles as it exerts forces in the flow direction resulting in rolling and sliding of sediment particle. Similarly, the ejection event has been considered important for sediment transport since these events maintain the sediment particles in suspension. In this paper, the nature of bursting events and in particular, the sweep events were studied in a model of braided river with a central island. The instantaneous velocities of flow were measured using the ADV. The turbulent stresses were determined from these instantaneous velocities. Box–Cox transformation is applied to transform the original data into a normally distributed data. The velocity measurements near the braided bar were made at 12 vertical sections using an ADV. The maximum value of turbulent kinetic energy and the R...

Experimental Investigation on a Ducted Savonius Vertical Axis Wind Turbine and its Performance Comparison with and without Endplates

Abstract: As the energy demand is growing and fossil fuel based energy resources are getting depleted, there has been an increased focus on the use of renewable energy resources. Wind energy is a highly suitable energy resource that can be harvested for the purpose. This research deals with the design and fabrication of novel designs as a mean to harness wind energy using a ‘Savonius’ Turbine. It is generally employed to harvest the low to very low wind speed potentials. The paper introduces a novel concept about a Ducted Savonius wind turbine where power generation can increase more than 10 folds. The paper provides experimental validation of the effect of using a converging ducted structure with a single stage and double stage configurations of a Savonius wind turbine. The paper also compares the turbine’s performance with and without endplates and compares Single Stage and Double Stage Turbine. The experiment results show that around 15% increase in tangential blade velocity in single stage rotor when end plates are used. The results of the study proves that power coefficient increases with the addition of a converging ducted structure with the Savonius wind turbine, and also with the use of endplates.

An Efficient Premiumness and Utility-Based Itemset Placement Scheme for Retail Stores

Abstract: In retail stores, the placement of items on the shelf space significantly impacts the sales of items. In particular, the probability of sales of a given item is typically considerably higher when it is placed in a premium (i.e., highly visible/easily accessible) slot as opposed to a non-premium slot. In this paper, we address the problem of maximizing the revenue for the retailer by determining the placement of the itemsets in different types of slots with varied premiumness such that each item is placed at least once in any of the slots. We first propose the notion of premiumness of slots in a given retail store. Then we discuss a framework for efficiently identifying itemsets from a transactional database and placing these itemsets by mapping itemsets with different revenue to slots with varied premiumness for maximizing retailer revenue. Our performance evaluation on both synthetic and real datasets demonstrate that the proposed scheme indeed improves the retailer revenue by up to 45% w.r.t. a recent existing scheme.

Asymmetric-donor (D2D2′)–acceptor (A) conjugates for simultaneously accessing intrinsic blue-RTP and blue-TADF

Abstract: The development of new photoluminescent (PL) materials with simultaneous room-temperature phosphorescence (RTP) and thermally activated delayed fluorescence (TADF) features is highly desirable for bio-imaging, security applications and sensors due to the involvement of both singlet and longer-lived triplet states. Here, we report two carbazolyl-phenoxy-phthalonitrile conjugates (CPPN, CPPNF). Spectroscopic studies combining two daughter compounds (PPN, PPNF) in polar and nonpolar hosts confirmed efficient blue-RTP from the higher-energy triplet state (TPPN) due to the phenoxy-phthalonitrile (PPN) part, and blue-TADF via reverse intersystem crossing from the low-lying triplet state (TCzPN) of the carbazolyl-phthalonitrile (CzPN) part to the singlet (S1) state of the same CzPN part, utilizing the TPPN state that acts as an intermediate for spin–vibronic coupling. Such PL characteristics are observed due to the energetic proximity of 3LEPPN, 1CTCzPN and 3CTCzPN. In the hydrogen-bonded matrix and crystals, we found faint persistent green-RTP characteristics of the PPNF due to supramolecular interactions and aggregation of the molecule. This study could pave the way to understanding the involvement of different excited states associated with TADF and RTP processes of asymmetric-donor–acceptor systems.