Rishi Bankim Chandra Colleges are a group of three co-located general degree colleges located in Naihati, West Bengal, India, namely Rishi Bankim Chandra College for Women, operating in the morning shift, Rishi Bankim Chandra College, operating in the day shift, and Rishi Bankim Chandra Evening College, operating in the evening shift. They offer undergraduate courses in arts, commerce and sciences. The three colleges are affiliated to West Bengal State University.
This paper explores the contribution of naiyᾱyika Bhāsarvajña (c. 950 CE) in Indian Nyāya Philosophy. He was one of the most celebrated figure of medieval Indian philosophy and his work centres around at the intersection of Classical Nyāya and the critical debates of his time with the school of Buddhist and Jaina philosophers. Focusing on his iconoclastic work ‘Nyāyasāra’, this paper will try to explore how his definition of Perception (Pratyakṣa) both differ from Maharṣi Gautama’s original doctrine of Perception and yet remains faithful to the core fundamentals of Nyāya tradition. Bhāsarvajña’s neo conception of Perception as “the instrument of correct and direct cognition” [“samyak aparokṣa anubhava sādhanaṁ pratyakṣam”] not only gave him liberty to confront and defend the contemporary challenges against Nyāya philosophy, but it also allowed him expand the possibility of Nyāya Epistemology to include both ordinary and higher forms of experience. His methods made him look like an ‘Ekadeśī’ philosopher, who was influenced selectively form different schools of traditions yet remain faithful to his own identity and school. In this way, Bhāsarvajña contributed in shaping the progress and development of Indian Logic and Epistemology during a decisive moment of intellectual turmoil.
This paper summarizes the science outcomes of the first Workshop on Data Analysis using observations from the XSPECT payload onboard the XPoSat, which brought together early-career researchers and experts to explore the instrument's scientific capabilities through lectures and hands-on analyses. Participants performed end-to-end data analysis, including calibration, spectral modeling, and timing studies, on seven sources comprising Neutron Star Low-Mass X-ray Binaries, pulsars, and Black Hole X-ray Binaries, demonstrating the instrument's scientific potential. The observations, obtained during the first year of XSPECT operations, together with in-house developed software, were provided to the participants, making them the first users outside the instrument team to analyze XSPECT data. For NS-LMXBs, Aql X-1 exhibited a classical Type-I X-ray burst, enabling constraints on the stellar radius through spectral fitting. Sco X-1, observed across its complete Z-track, revealed systematic spectral evolution driven by accretion-rate fluctuations and disk-corona coupling, while Cir X-1 displayed orbital phase-dependent transitions between hard and soft states, reflecting changes in accretion geometry. Among accretion-powered pulsars, GX 301-2 showed a double-peaked, energy-dependent pulse profile and strong iron fluorescence lines due to stellar wind reprocessing, whereas Vela X-1 exhibited orbital phase-dependent absorption and steady coronal temperatures. Among BH-XRBs, Cyg X-1 transitioned from a hard to soft-intermediate state with increasing disk contribution and spectral softening, while Cyg X-3 remained in the intermediate state with multiple emission lines originating from a clumpy stellar wind. The workshop outcomes highlight the scientific promise of XSPECT and the importance of collaborative training in maximizing the science from XSPECT and future Indian space astronomy missions.
Binary complexes of 7-azaindole (7AI) with various proton donor-acceptor species have long been used as prototypical systems to investigate double-proton exchange tautomerization as the key photochemical pathway of these complexes. Here, we demonstrate the occurrence of an alternative and faster electronic relaxation pathway of different degrees and suppression of double-proton exchange tautomerization in a series of binary complexes of 7AI with polyfluorophenols (FnPhOHs, where n = 0-5). The efficiency of the alternative excited-state relaxation channel is correlated with the quenching efficiency of the UV fluorescence from the locally excited state of 7AI. The quenching efficiency is found to be dependent on the number of fluorine substitutions on the phenolic sites, and the Stern-Volmer quenching constant (KSV) values increase by more than an order of magnitude from phenol (PhOH) to pentafluorophenol (F5PhOH). The quenching efficiency displays a linear correlation with the binding energies of the binary complexes between 7AI and FnPhOHs in the ground state. Furthermore, quenching is found to be greatly enhanced with the lowering of the temperature of the medium, which promotes complex formation, implying that quenching is static in nature. Given that the acidity of fluorophenols increases with the number of fluorine substitutions, the origin of the alternative electronic relaxation of 7AI is associated with a proton-coupled electron transfer (PCET) process. Electronic structure theory calculations indeed show the enhanced feasibility of PCET in the binary complexes of 7AI from PhOH to F5PhOH.
A Cu(II) complex with 3-methylpyridine-2-carboxylic acid, formulated as (C14H12CuN2O4)n (Complex I), was synthesized and characterized using infrared spectroscopy (IR), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. The crystal structure of Complex I is monoclinic, space group P2₁/c, with unit-cell parameters a = 4.9892(6) Å, b = 15.002(2) Å, c = 8.5649(12) Å, and volume V = 638.49(15) Å3. The Cu(II) center adopts a quasioctahedral coordination geometry and is located at a crystallographic inversion center. Density functional theory (DFT) calculations and Hirshfeld surface analysis revealed that noncovalent interactions, including H···O, H···C, and π···π contacts, play a significant role in stabilizing the three-dimensional supramolecular architecture of the complex.
The [2 + 2] cycloaddition of alkenes is thermally forbidden and traditionally achieved through high-energy UV irradiation. However, recent advances in triplet energy transfer (EnT) enable these cycloadditions under visible light, offering mild, selective and sustainable access to cyclobutane scaffolds. With an emphasis on the key mechanistic aspects, this review highlights recent (2022-2025) advances in energy-transfer mediated inter- and intramolecular [2 + 2] photocycloadditions of olefinic substrates with efficient strategies for the construction of cyclobutane frameworks. The intermolecular reaction section is categorized into alkene-alkene [2 + 2] cycloadditions, alkene-heterocycle [2 + 2] cycloadditions, and aza-/thia-Paternò-Büchi reactions. The intramolecular reaction section is subdivided into [2 + 2] cycloadditions involving hetero-/carbocycles and acyclic analogues. In addition, recent EnT-mediated [2π + 2σ] cycloadditions are discussed, exploring new opportunities to activate strained substrates.
