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In situ synthesized graphene quantum dots (GQDs) decorated with green synthesized AgNPs (AgNPs@GQDs) hybrid nanofillers reinforced polyaniline (PANI) ternary nanocomposites was synthesized by in situ polymerization. The UV-Vis spectroscopy showed the presence of AgNPs at 402 nm in AgNPs@GQDs hybrid nanofillers, and a charge transfer complex was formed between PANI matrix and AgNPs@GQDs hybrid nanofillers. The direct optical band gap of the ternary nanocomposites calculated from UV-Vis analysis is found to be 3.085 eV, which indicates the ternary nanocomposite may be used for solar cell applications. The Fourier transfer infrared (FTIR) spectroscopy represented the occurrence of interphase interactions between the ternary nanocomposites. The X-ray diffraction (XRD) data showed the positions and intensities of the hybrid nanofillers and PANI matrix. The morphology of the ternary nanocomposites was confirmed by scanning electron microscopy (SEM). The thermogravimetric analysis (TGA) attributed to the thermal degradation of the ternary nanocomposites. The cyclic voltammetry (CV) showed the oxygen reduction potential of the ternary nanocomposites. Photoluminescence (PL) activity of the ternary nanocomposites was confirmed by fluorescence spectroscopy. The AC conductivity of the ternary nanocomposites significantly increases as compared to pure PANI due to the presence of uniformly distributed hybrid nanofillers within PANI matrix. [ABSTRACT FROM AUTHOR]

Tourism thrives upon the benefits of providing safer and risk-free systems, yet empirical evidence in developing economies still needs to be explored. Our study examines how crime and terrorist activities impact tourist demand in Indian states. We use panel data for 27 Indian states and 2 Union Territories from 1993 to 2022. Our findings confirm the differential impact of violent and non-violent crimes on tourism demand in India. We find that a 10% increase in violent and non-violent crimes leads to a decline in tourist arrival by 5.2% and 1.6%, respectively. Further, the result shows that terror mortality exhibits an inverse relation with tourist inflows, whereas improvements in hotel beds attract tourist inflows. In addition, estimates confirm that more urban expenditures enhance tourist inflows, although the effects remain marginal. Our results are consistent in different econometrics specifications. [ABSTRACT FROM AUTHOR]

A novel chromone-based Schiff base L was designed and synthesized by condensing an equimolar amount of 3-formyl chromone and 2,4-dinitro phenyl hydrazine. Schiff base L was developed as a potent colorimetric and fluorescent molecular probe to recognize Hg2+ ions over other competitive metal ions. In the presence of Hg2+, Schiff base L displays a naked-eye detectable color change under day and UV365 nm light. Various UV-Vis and fluorescence studies of L were performed in the absence and presence of Hg2+ to determine the sensitivity and the sensing mechanism. With high selectivity and specificity, the detection limit and association constant of L for Hg2+ were estimated at 1.87 µM and 1.234 × 107 M−1, respectively. The developed sensor L was applied to real soil samples for the detection of Hg2+. [ABSTRACT FROM AUTHOR]

Advances in satellite Earth observation have opened up new opportunities for global monitoring of soil moisture (SM) at fine to medium resolution, but satellite remote sensing can only measure the near-surface soil moisture (SSM). As such, it is critically important to examine the potential of satellite SSM measurements to derive the water resource variations in deeper subsurface. This study compares the SSM variability captured by the Soil Moisture Active and Passive (SMAP) satellite and the Soil Water Index (SWI) derived from SMAP SSM with subsurface SM and groundwater (GW) dynamics simulated by a high-resolution fully integrated surface water–groundwater model over an agriculturally dominated watershed in eastern Canada across two spatial scales, namely SMAP product grid (9 km) and watershed (∼4000 km2). SMAP measurements compare well with the hydrologic simulations in terms of SSM variability at both scales. Simulated subsurface SM and GW storage show lagged and smoother characteristics relative to SMAP SSM variability with an optimal delay of ∼1 d for the 25–50 cm SM, ∼6 d for the 50–100 cm SM, and ∼11 d for the GW storage for both scales. Modeled subsurface SM dynamics agree well with the SWI derived from SMAP SSM using the classic characteristic time lengths (15 d for the 0–25 cm layer and 20 d for the 0–100 cm layer). The simulated GW storage showed a slightly delayed variation relative to the derived SWI. The quantified optimal characteristic time length Topt for SWI estimation (by matching the variations in SMAP-derived SWI and modeled root zone SM) is comparable to Topt obtained in other agricultural regions around the world. This work demonstrates SMAP SM measurements as a potentially useful aid when predicting root zone SM and GW dynamics and validating fully integrated hydrologic models across different spatial scales. This study also provides insights into the dynamics of near-surface–subsurface water interaction and the capabilities and approaches of satellite-based SM monitoring and high-resolution fully integrated hydrologic modeling. [ABSTRACT FROM AUTHOR]

We examine the effectiveness of green innovation on CO2 emissions in the top twelve polluting nations—China, the US, India, Russia, Japan, South Korea, Canada, Mexico, Turkey, Italy, Poland, and the UK—from 1996 to 2020. Using panel data fixed and random effect model and decision tree analysis, we found that industrialization, urbanization, and economic growth increase CO2 emissions, whereas green energy consumption and governance decrease CO2 emissions. In the panel data tree-based model, governance is in the second and third positions in the decision tree fixed, and random effect model. Green innovation is not statistically significant despite the expected negative sign. The findings suggest that policymakers should encourage investment in green energy production and governance to combat environmental degradation. Investment in green energy should be escalated to ensure energy efficiency in the long term. [ABSTRACT FROM AUTHOR]

The synthesis of gold nanoparticles reinforced functionalized single‐walled/multi‐walled carbon nanotubes nanohybrid based polyaniline nanocomposites were carried out using in situ polymerization. The chemical interaction and nanostructured morphology of the synthesized nanocomposites are studied using ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, x‐ray diffraction analysis, x‐ray photoelectron spectroscopy, and field emission scanning electron microscopy. Thermal stability of synthesized PANI/Au@f‐SWNTs is boosted by a magnitude of 30°C as compared with the pristine PANI matrix, which is attributed to a strong barrier effect because of the development of tortuous path that resulted from a uniform distribution of Au@f‐CNTs throughout the PANI matrix. For PANI/Au@f‐SWNTs, the AC conductivity and dielectric permittivity are improved by a value of 83.58 S/cm and 1.35 × 10−5 as well as the dielectric loss is reduced by a factor of 0.11 in comparison with the pure PANI matrix at an applied frequency of 106 Hz. PANI/Au@f‐SWNTs and PANI/Au@f‐MWNTs ternary nanocomposites exhibited excellent selectivity toward the hazardous Cr(VI) heavy metal ions in an aqueous medium with a limit of detection of 0.74 and 0.89 μM with a binding constant of 1.028 × 105 and 3.46 × 104 M−1, respectively, that can be selective and sensitive for the detection of Cr(VI) metal ions in water at trace level. [ABSTRACT FROM AUTHOR]