Banwarilal Bhalotia College, known by the abbreviation B. B. College, established in 1944, is a college in Asansol, Paschim Bardhaman district, West Bengal, India. It offers undergraduate courses in arts, commerce and sciences. It is affiliated with Kazi Nazrul University, Asansol. B.
Interferometric observations of the low-frequency radio sky (<1 GHz) are largely limited by systematic effects introduced by the ionosphere. Here, we analyse a ten-hour nighttime uGMRT Band-4 observation of 3C48 to characterize ionospheric phase fluctuations across baselines up to 25 km. We compute spatial phase structure functions across three sub-bands (575-725 MHz), revealing power-law behaviour consistent with turbulence and a diffractive scale r (diff) approximate to 6.7-8.3 km useful for assessing calibration requirements. The turbulence exhibits anisotropy with smallest scales perpendicular to Earth's magnetic field - consistent with wave-like structures such as MSTIDs rather than field-aligned irregularities. These findings from a single case study demonstrate uGMRT's sensitivity for ionospheric characterization at low-latitudes (similar to 19 degrees N) and inform direction-dependent calibration strategies for similar conditions.
We present a detailed depolarization analysis of the radio galaxy 𝙸𝙻𝚃𝙹𝟶𝟷𝟸𝟸𝟷𝟻.𝟸𝟷+𝟸𝟻𝟺𝟹𝟹𝟺.𝟾 using polarimetric data from the 𝐿𝑂𝐹𝐴𝑅 Two-metre Sky Survey} (LoTSS) Data Release 2 (DR2) catalogue. This source, with ~ 47 rad m and projected linear size ~ 335 kpc at z ≈ 0.05 , serves as a pilot for systematic qu-fitting of mostly unresolved LoTSS sources, building on prior single-target studies that established the need for multi-component Faraday models in complex magneto-ionic media. Fitting five depolarization models to the LoTSS HBA (120-168 MHz) fractional polarization spectra reveals a decisively preferred three-component model (one Faraday-thin instrumental leakage, plus two external Faraday dispersions), demonstrating that LoTSS data alone can constrain moderate Faraday complexity in typical DR2 galaxies. Our results highlight turbulence and inhomogeneity in the foreground magneto-ionic medium and outline a path for population studies of LoTSS FR-I sources.
We consider spin-orbit coupled Bose-Einstein condensates with cubic-quintic nonlinear interaction within the framework of second quantization formulation and find eigen states using numerical simulation and mean-field approximation. We show that two low-lying Schr & ouml;dinger cat states remain degenerate upto a certain value of Raman coupling strength and these states can serve as qubit basis. We take three different nonlinear perturbations and find that the perturbations can result in different rotations of qubit state on Bloch sphere. We calculate the unitary operator corresponding to each perturbation and suggest the possibilities for obtaining various gates in ultra-cold atomic system.
The blue economy, encompassing sustainable use of coastal and oceanic resources for economic growth, environmental health, and improved livelihoods, is critically influenced by salinity fluctuations of the marine and estuarine ecosystems. This research explores the impact of salinity on the blue economy in the inshore region of the Bay of Bengal, particularly focusing on the Bali Island sampling station located in the central sector of Indian Sundarbans. Surface water salinity data from 1984 to 2024 was collected during high tide, forming the basis of trend analysis and forecasting up to 2050 with an AI-based Neural Auto-Regressive (NAR) model. The study identifies potential adverse effects on infrastructure, tourism, and biodiversity. It also reviews the policy framework addressing salinity-related challenges, emphasizing the urgent need for adaptive strategies.
Despite its agroecological diversity, the Eastern Himalayan Region (EHR) is highly vulnerable to climate variability, but long-term, subregional climate diagnostics are still lacking. This study offers one of the earliest comprehensive assessments of the EHR at the Agroecological Subregion (AESR) scale in terms of hydroclimatic conditions. For this, high-resolution long-period (1951-2020) gridded (0.25° × 0.25°) daily rainfall and temperature data from 84 IMD stations distributed across AESRs were analyzed. To assess trends, the Mann-Kendall test and Sen's slope estimator were employed, while rainfall variability, concentration, droughts, and flood frequencies were delineated using diverse hydroclimatic indices. The following indices were utilized: PCI, APCI, MPCI, standardized precipitation anomaly (PI), climatic water balance (CWB), and SPEI. The findings reveal strong spatial variations across AESRs. In the high-altitude Himalayan regions (AESRs 16.2 and 16.3), there was an intensification of rainfall. While in the Upper Brahmaputra Plain (AESR 15.4) and Purvanchal Hills (AESR 17.2), rainfall decreased, this occurred alongside an elevated frequency of droughts. The region experienced a 0.52°C increase in maximum temperatures and a 0.32°C increase in minimum temperatures, with significant warming post-1986 except in AESR 16.2. The decrease in regional climatic water surplus by 7.2% over seventy years caused a pronounced moisture deficit. This could have affected planting schedules, crop phenology, and soil moisture recharge for key rainfed crops such as rice, tea, and mustard. AESRs primarily composed of agroforestry systems demonstrate a capacity to buffer, thereby sustaining a diverse range of production (including crops, fruits, fodder, timber) while boosting carbon sequestration and biodiversity conservation. These spatial contrasts underscore the need for AESR-specific adaptation strategies, including flood early warning systems in plains, drought-resilient crops in uplands, and policy support for agroforestry-based systems across the EHR.
