The Great Mica Belt of Jharkhand, India, is an intensively disturbed mining region due to long-term mica extraction, which increases anthropogenic pressures on environmental components. Despite the environmental fragility of this region, systematic baseline information on rainwater chemistry and trace metal deposition has been lacking, particularly in comparison to other mining-impacted regions where such studies are more extensively documented. Addressing this gap is crucial for understanding atmospheric deposition processes in mining-dominated landscapes of eastern India. Unlike previous studies that predominantly focus on coal-mining, urban, or industrial regions, this study specifically investigates a mica-mining dominated environment, which has distinct mineralogical composition and emission characteristics influencing rainwater chemistry. This study aims to evaluate the chemical composition and trace metal concentrations of monsoonal rainwater collected at Koderma and Tisri within the Great Mica Belt. A total of 60 rain water samples were analyzed for physicochemical parameters (pH, EC, TDS), major and minor ions (i.e., Ca2⁺, Mg2⁺, Na⁺, K⁺, Cl⁻, HCO₃⁻, SO₄2⁻, NO₃⁻, NH₄⁺ and F⁻), and metals. Source contributions were evaluated using enrichment factor (EF), non-sea-salt fraction (nssf), and neutralization factor analyses. Rainwater pH ranged from 5.38 to 7.26, indicating acidic to alkaline conditions, with 9
In this work, the structural, electrical, electro-thermal, and switching properties of As2Se3-doped Ge2Sb2Te5 films have been studied. Upon annealing, the films undergo a phase transition at higher temperatures from the amorphous state to a stable hexagonal phase via a metastable face-centered-cubic phase, notably without any observed phase separation and lattice distortion. Doping with As2Se3 significantly improves the thermal stability of the amorphous phase, increasing the crystallization temperature from-168 degrees C to-225 degrees C (x = 0.21). The band gap is increased due to the formation of high-energetic Ge-Se and As-Se bonds. Furthermore, the data retention temperature for a 10-year period is substantially improved from 78 degrees C to 124.93 degrees C with a corresponding increase in the activation energy. The threshold current required for phase transformation is reduced to 0.23 mA. Higher-doped films generate more Joule heat due to their increased resistivity, which, in turn, allows for a reduction in power consumption for the same applied current, indicating promising applications in phase change memory devices.
This study from Hulas Khera, in the Central Ganga Plain, reconstructs past climatic conditions and lake-level fluctuations since similar to 6350 calibrated years BP. It integrates sediment textural analysis, mineral magnetism, elemental composition, and AMS radiocarbon dating. Variations in detrital input reflect catchment erosion associated with shifts in rainfall patterns, indicating precipitation as the primary driver of magnetic property changes. The C-M diagram indicates floodplain deposition, driven by suspension settling. Grain-size end-members EM1 and EM2 (mean sizes: 8.9 and 53 mu m) in the fine to coarse silt domain are associated with surface runoff during periods of heightened seasonal precipitation, corresponding to intensified Indian Summer Monsoon activity around 5400 to 4600, 4000, 3300, 2000, and 800 cal yrs. BP. In contrast, EM3 and EM4 (mean sizes: 92 and 160 mu m), within fine sand domain, are prominent during intervals of extended drought and monsoon minima around similar to 6300-5400, similar to 4300, similar to 3600, similar to 2800-2200, similar to 1800-900, and similar to 600-300 cal yrs. BP, coinciding with regional dry phases recorded in the Kanwar Lake record from the Central Ganga Plain, and reduced upwelling record of the Arabian Sea. Abrupt shifts in Indian Summer Monsoon (ISM) strength recorded correspond to known monsoon minima during the Little Ice Age and the Dark Age Cold Period, highlighting the sensitivity of regional hydrodynamics to mid- to late-Holocene monsoonal variability.
MXene is a youngest member of two-dimensional (2D) materials community having controlled structure, unique composition and highly chemical active surface functionality. The layered structure of Mxene possesses high surface area, high porosity, high metallic order conductivity, flexibility, which offers them as a suitable and potential material for detection of environmental gases and analytes. In the present study, Ti3C2 MXene nanosheets were synthesized by selectively etching the Al layers from Ti3AlC2 MAX phases using hydrofluoric acid (HF) under prolonged stirring. The chemiresistive type sensor configuration was prepared, where synthesized Ti3C2 nanosheets were used as active layer to detect the hydrogen (H2) gas at room temperature. The prepared samples were irradiated by 10 key N+ ion at three different flounces of 1x1015, 5x 1015 and 1x 1016 ions cm- 2 using indigenously developed low energy ion beam table top accelerator. The comparative study have been done to analyse the impact of ion irradiation on skelton, surface changes, and H2 gas sensing of Ti3C2 MXene nanosheets after and before irradiation. It was observed that after irradiation, the sensor exhibited a higher and faster response, with the response magnitude increasing linearly with ion fluence. The maximum response value reached 2.1 for the sensor irradiated at ion fluence of 1x1016 ions cm- 2, compared to a value of 1.37 for the pristine Ti3C2 MXene sensor. After irradiation the sensor show a faster response and recovery in comparison to that pristine MXene thin film sensor and optimized response and recovery time performance were found 98 s and 109 s, respectively for the sample irradiated at higher ion fulence (1x1016 ion cm- 2). The findings demonstrate that the ion irradiation has a significant effect on the structural and morphological properties of MXene nanosheets, which in turn enhances their gas sensing performance and with increasing ion fluence, the sensor demonstrates good short as well as long term stability, exhibiting a consistent response pattern and faster response as well as recovery in comparison to pristine Ti3C2 MXene sensor. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were employed to investigate the surface morphology and microstructural properties of the fabricated MXene samples.
This study presents integrated paleoseismic and geodetic studies from the Kaladungi Fault (KF) in the Kumaon-Garhwal Himalaya to constrain the rupture history of major historical earthquakes. A paleoseismic trench excavated at the base of a 15 m high fault scarp at Nandpur revealed geological evidence of four surface-rupturing paleoearthquakes. In total 24 Optically Stimulated Luminescence (OSL) and 24 radiocarbon (14C) ages allowed robust bracketing of these events. Based on offsets of sedimentary units and ages we infer that Event-I took place between BCE 2945-1990 and BCE 1480-862, and Event-II was between BCE 1264-643 and BCE 793-287. These events could not be correlated with any paleo-earthquakes due to broad age brackets and nonavailability of any pre-historic records. Event-III occurred between CE 1242-1408 and CE 1415-1529, while Event-IV (MRE) was between CE 1692-1761 and CE 1689-1822. To constrain and correlate the rupture lengths of Event III and Event IV, we considered historical records and regional paleoseismic data from Nepal, Kumaon-Garhwal to the western Himalaya. The Event-III corresponds to the CE 1505 earthquake and Event-IV (MRE) represents the CE 1803 earthquake. Moreover, the long-term slip-rate for the KF is estimated to be similar to 7.1 mm/yr, which suggests the similar to 40% of the total slip (similar to 17.7 mm/yr, estimated from geodetic) being partitioned on this fault. Paleoseismic evidence for the CE 1803 event indicates surface rupture, as demonstrated by fault displacements and tightly bracketed ages, countering previous claims of a blind rupture. Supporting this interpretation, geodetic modeling and seismicity patterns constrain the downdip locking extent of the Main Himalayan Thrust to similar to 100 km north of the Main Frontal Thrust. The reassessment of rupture dimensions for CE 1803 event aligns with a seismic moment magnitude Mw similar to 8.1-8.2 rupture. With updated strain budget of similar to 3.9 m of elastic strain accumulated since 1803, the region now represents a mature seismic gap with potential for another great earthquake. This study underscores the importance of integrating trench-based paleoseismic chronologies with GPS-constrained crustal deformation models to enhance seismic hazard assessments along the Himalayan front.
