Indian Institute of Technology Bhubaneswar

About: Indian Institute of Technology Bhubaneswar is a education organization based out in Bhubaneswar, India. It is known for research contribution in the topics: Large Hadron Collider & Computer science. The organization has 1185 authors who have published 3132 publications receiving 48832 citations.

Protonation of Cytosine: Cytosinium vs Hemicytosinium Duplexes

Abstract: Cytosine, a nucleobase, can exhibit two protonated states, cytosinium and hemicytosinium. The controlled synthesis of structures containing these ions is highly desired but not yet achieved. Herein, we report strategies for robust synthesis of both structures by controlling the strength of an acid used for protonation and its concentration. The duplex structure is always obtained by using an acid with a pKa > 4.2, which is incapable of disrupting the relatively stable duplex structure. When stronger acids (pKa < 4.19) are used, the duplex structure is obtained by controlling acid concentration to protonate a half of cytosine in solution, and the cytosinium structure is obtained with excess acid. These strategies are successfully applied to synthesize both forms of 5-fluorocytosine, an antifungal drug. The hemicytosinium structure exhibits superior physicochemical properties than the parent drug and the cytosinium salt. These strategies may be useful to prepare materials important to various branches of sc...

On the performance of Tamm-plasmon and surface-plasmon hybrid-mode refractive-index sensor in metallo-dielectric heterostructure configuration

Abstract: Hybrid modes formed as a consequence of coupling between Tamm-plasmon polariton (TPP) mode and surface plasmon polariton (SPP) mode in a metallo-dielectric heterostructure geometry exhibit interesting dispersive features which can be employed for realizing highly sensitive and accurate surface-plasmon-resonance (SPR) sensor. The transverse magnetically (TM) polarized TPP modes (TM-TPP), formed at the interface of distributed-Bragg reflector (DBR) and metal, are strongly dispersive as compared to SPP modes at optical frequencies that forms the basis of narrow interaction bandwidth which, in turn, results in improved accuracy of sensing. By deploying a nano/micro-fabrication compatible TiO 2 /SiO 2 -based DBR architecture in combination with different plasmon-active metals such as gold (Au), silver (Ag) and aluminum (Al), we propose a TM-TPP and SPP hybrid-mode sensor which exhibit high sensitivity ≥ 900 nm/RIU for analyte refractive indices varying between 1.330 and 1.345. The investigation also revealed that the hybrid-mode sensor is most accurate in case of Al-based configuration amongst Au, Ag and Al which is primarily due to weaker dispersion characteristics exhibited by Al at visible frequencies. Since, the dispersive behavior of TM-TPP modes could be tailored appropriately in any spectral band, the sensing configuration could be immensely useful for designing sensors at those wavelength where optical sources are readily available.

A comprehensive protection scheme for micro-grid using fuzzy rule base approach

Abstract: The paper presents a comprehensive primary and backup protection scheme for micro-grid using fuzzy rule base approach. The proposed scheme starts with pre-processing of the retrieved current and voltage signals at both ends of the faulted feeder and adjacent feeder to compute the differential features. The differential features are used to build two separate decision trees (DTs) for the primary and backup protection. The differential features between immediate buses of faulted feeder are considered for primary protection and differential features between far end buses of faulted and adjacent feeders are used to build decision tree for secondary protection. From the developed decision tree classification boundaries, the fuzzy membership functions are generated and the corresponding fuzzy rule base is formulated for final relaying decision. The proposed scheme is tested for numbers of fault and no fault events simulated in the studied micro-grid with wide variations in system parameters and fault parameters in different operating mode. The extensive test results show the efficacy of the proposed protection scheme to provide a reliable protection measure to both primary and backup protection of micro-grid.