An Efficient Route for the Synthesis of Flavans Using Sequential One-pot Jeffery Heck Coupling and Reduction as Key Protocol

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Theoretical Investigation of α-decay Chains of Fm-isotopes

Background: The theoretical and experimental investigations of decay properties of heavy and superheavy nuclei are crucial to explore the nuclear structure and reaction dynamics. Purpose: The aim of this study is to probe the α-decay properties of 243Fm and 245Fm isotopic chains using relativistic mean-field (RMF) approach within the framework of preformed cluster-decay model (PCM). Methods: The RMF densities are folded with the relativistic R3Y NN potential to deduce the nuclear interaction potential between the α particle and daughter nucleus. The penetration probability is calculated within the WKB approximation. Results: The α-decay half-lives of even-odd 243Fm and 245Fm isotopes and their daughter nuclei are obtained from the preformed cluster-decay model. These theoretically calculated half-lives are found to be in good agreement with the recent experimental measurements. Conclusions: The novel result here is the applicability of the scaling factor within the PCM as a signature for shell/sub-shell closures in α-decay studies. As such, we have also demonstrated that N=137, 139 and Z=94 corresponding to 231,233Pu could be shell/sub-shell closures. The least T1/2 is found at 243,245Fm which indicate their individual stability and α-decay as their most probable decay mode

Design of Compact Antenna Array for MIMO Implementation Using Characteristic Mode Analysis for 5G NR and Wi-Fi 6 Applications

In this paper, we present a compact antenna for 5G new radio (NR) and Wi-Fi 6 applications. Using characteristic mode analysis (CMA), two orthogonal modes have been separated and then a gap-coupled shaped feed-line has been used to excite the radiator. An open stub is added to achieve the wide operating bandwidth of the antenna. The size of a single antenna element and the 1 $\times$ 2 array-unit (AU) are 20 $\times$ 21.5 mm2 and 40 $\times$ 21.5 mm2, respectively. The operating and fractional bandwidths (FBW) of the AU are 5.18–7.71GHz and 39.25%, respectively. The proposed AU is used to develop a number of radiating element-independent multiple-input-multiple-output (MIMO) antennas comprising of 2AUs, 4AUs, and 8AUs with identical electrical characteristics and good isolation ( ${I}$ ) ≥ 18.8 dB. All the AUs have realized gain ~ 3.0 dBi, and the total antenna efficiency ~ 70% making it suitable for the single-user MIMO (SU-MIMO) and multiple users MIMO (MU-MIMO) needed for Wi-Fi 6 applications. To show the application of these antennas, the deployment scenario of a 16AUs MIMO antenna on a large size ground plane which mimics the smart TV panel and router chassis, etc., is also presented. These AUs may find potential applications in radiator-number independent MIMO systems