Development of a method to identify change in the pattern of extreme streamflow events in future climate: Application on the Bhadra reservoir inflow in India

Study region: Bhadra basin (1968 km2), located in peninsular India, is considered for demonstration. Study focus: A general framework to assess the impact of climate change on the pattern of daily extreme streamflow events is proposed. Whereas, the impact is confirmed in the recent literature for most of the hydrologic variables at monthly/seasonal time scale, assessment and quantification at finer time scale, e.g. daily, is challenging. Complexity increases for the derived hydrologic variables, such as soil moisture and streamflow as compared to primary hydrologic variables, such as precipitation. The proposed general framework is demonstrated with the daily inflow to the Bhadra reservoir. Different statistical limits of extremes are defined and change in daily extreme pattern (number and magnitude) in the future (2006–2035) is assessed with respect to the baseline period (1971–2000). New hydrological insights for the region: Demonstration of the proposed methodology with the inflow to Bhadra reservoir reveals that the daily extreme events are expected to increase in number with the increase in the threshold of the extreme. For a particular threshold, the average magnitude of the extreme events in the future is found to be higher as compared to the baseline period. However, for monthly totals the case is not the same − it remains almost similar. The methodology, being general in nature, can be applied to other locations in order to assess the future change in streamflow and other derived variables

AN AN UPDATED REVIEW ON HERBAL DRUGS: NOOTROPIC ACTIVITY AND POSSIBLE MECHANISMS

Nootropic drugs are those which are proclaimed to direct toward boosting the cognitive capabilities. Memory encodes, decodes, and stores information. Cognitive deficits or memory impairment that is present with neuropsychiatric conditions insists adoption of nootropics to improve cognitive abilities. At present, there is an enormous impulse to analyze medicinal plants worldwide for bettering cognitive behavior due to their minimal adverse effects. This paper is a review to refurbish knowledge on therapeutic and pharmacological actions along with major chemical constituents, safety, and conceivable mechanism of action of the chosen herbs from ayurvedic pharmacopoeia. Simultaneously, it comes up with further investigation and standardization on nootropic herbs

Advancements in wearable ammonia sensors using polypyrrole/MWCNT coated yarn

In this study, we utilized a dip coating method to modify insulating yarn with polypyrrole and multiwall carbon nanotubes (MWCNTs) to convert it into a conductive yarn. The resulting fabricated conducting yarn underwent thorough characterization through scanning electron microscope, x-ray diffraction pattern, and thermal gravimetric analysis. Subsequently, we examined the ammonia sensing properties of the modified yarn at various stages of its development. Our findings revealed that the combination of MWCNTs followed by polypyrrole modification significantly enhanced the ammonia sensing capabilities compared to using MWCNTs or polypyrrole-coated yarn individually. Specifically, the MWCNTs followed by polypyrrole modified yarn demonstrated an excellent sensing response, remarkable repeatability (up to 24 continuous cycles), quick response time (11 ± 2 s), and recovery time (34 ± 5 s). Additionally, the sensor exhibited good linearity in detecting ammonia vapor concentrations within the range of 20-100 ppm. We also assessed the sensor’s performance with diverse vapors at room temperature, revealing its high selectivity for ammonia. Furthermore, the sensor’s response correlated linearly with yarn length. Remarkably, it demonstrated minimal sensitivity to humidity and exceptional stability over fifty days. These results have the potential to lead to the development of wearable room temperature ammonia sensors, suitable for use in agricultural and industrial chemistry, as well as in environmental, automotive, and medical applications.ISSN:1361-665XISSN:0964-172

Development of a method to identify change in the pattern of extreme streamflow events in future climate: application on the Bhadra reservoir inflow in India

Study region: Bhadra basin (1968 km2), located in peninsular India, is considered for demonstration. Study focus: A general framework to assess the impact of climate change on the pattern of daily extreme streamflow events is proposed. Whereas, the impact is confirmed in the recent literature for most of the hydrologic variables at monthly/seasonal time scale, assessment and quantification at finer time scale, e.g. daily, is challenging. Complexity increases for the derived hydrologic variables, such as soil moisture and streamflow as compared to primary hydrologic variables, such as precipitation. The proposed general framework is demonstrated with the daily inflow to the Bhadra reservoir. Different statistical limits of extremes are defined and change in daily extreme pattern (number and magnitude) in the future (2006–2035) is assessed with respect to the baseline period (1971–2000). New hydrological insights for the region: Demonstration of the proposed methodology with the inflow to Bhadra reservoir reveals that the daily extreme events are expected to increase in number with the increase in the threshold of the extreme. For a particular threshold, the average magnitude of the extreme events in the future is found to be higher as compared to the baseline period. However, for monthly totals the case is not the same − it remains almost similar. The methodology, being general in nature, can be applied to other locations in order to assess the future change in streamflow and other derived variables

Highly Diastereo- and Enantioselective Synthesis of Spiro-tetrahydrofuran-pyrazolones via Organocatalytic Cascade Reaction between γ‑Hydroxyenones and Unsaturated Pyrazolones

The first diastereo- and enantioselective synthesis of spiro-tetrahydrofuran-pyrazolones is reported via organocatalytic asymmetric cascade oxa-Michael/Michael reaction between γ-hydroxyenones and unsaturated pyrazolones. Bifunctional squaramide catalyst was found to be effective for this reaction. With 10 mol % of catalyst, excellent results were attained for a variety of spiropyrazolones under mild reaction conditions

Highly Diastereo- and Enantioselective Synthesis of Spiro-tetrahydrofuran-pyrazolones via Organocatalytic Cascade Reaction between γ‑Hydroxyenones and Unsaturated Pyrazolones

The first diastereo- and enantioselective synthesis of spiro-tetrahydrofuran-pyrazolones is reported via organocatalytic asymmetric cascade oxa-Michael/Michael reaction between γ-hydroxyenones and unsaturated pyrazolones. Bifunctional squaramide catalyst was found to be effective for this reaction. With 10 mol % of catalyst, excellent results were attained for a variety of spiropyrazolones under mild reaction conditions

CdS Quantum Dot Gels as a Direct Hydrogen Atom Transfer Photocatalyst for C-H Functionalization

Here, we report CdS quantum dot (QD) gels, a three-dimensional network of interconnected CdS QDs, as a new type of direct hydrogen atom transfer (d-HAT) photocatalyst for C-H functionalization. We discovered that the photoexcited CdS QD gel could generate various neutral radicals, including α-amido, heterocyclic, acyl, and benzylic radicals, from their correspond-ing stable molecular substrates, including amides, thio/ethers, aldehydes, and benzylic compounds. Its C-H activation ability imparts a broad substrate and reaction scope. The mechanistic study reveals that this reactivity is intrinsic to CdS materials, and the neutral radical generation did not proceed via the conventional sequential electron transfer and proton transfer pathway. Instead, the C-H bonds are activated by the photoexcited CdS QD gel via a d-HAT mechanism. This d-HAT mechanism is supported by the linear correlation between the logarithm of the C-H bond activation rate constant and the C-H bond dissociation energy with a Brønsted slope α = 0.5. Our findings expand the currently limited direct hydrogen atom transfer photocatalysis toolbox and provide new possibilities for photocatalytic C-H functionalization

Organocatalytic Asymmetric Michael/Hemiketalization/Retro-aldol Reaction of α‑Nitroketones with Unsaturated Pyrazolones: Synthesis of 3‑Acyloxy Pyrazoles

An organocatalytic asymmetric cascade Michael/hemiketalization/retro-aldol reaction between unsaturated pyrazolones and α-nitroketones is described. A bifunctional thiourea catalyst was found to be efficient for this reaction. With 10 mol % of catalyst, high yields as well as excellent enantioselectivities are attained for a variety of 3-acyloxy pyrazoles under mild reaction conditions

Green Chemistry Based Gold Nanoparticles Synthesis Using the Marine Bacterium PBCW2 and Their Multitudinous Activities.

Green chemistry has paved an 'avant-garde avenue' in the production and fabrication of eco-friendly stable nanoparticles employing the utilization of biological agents. In the present study we present the first report on the potential of the marine bacterium Lysinibacillus odysseyi PBCW2 for the extracellular production of gold nanoparticles (AuNPs). Utilizing a variety of methods, AuNPs in the cell-free supernatant of L. odysseyi (CFS-LBOE) were identified and their antioxidant, antibacterial, and dye-degrading properties were examined. The visual coloring of the reaction mixture to a ruby red hue showed the production of LBOE-AuNPs; validated by means of XRD, TEM, SEM, XRD, DLS, TGA, and FT-IR analysis. Additionally, the 2,2-diphenyl-1-picrylhydrazyl technique and the well diffusion assay were used to examine their dose-dependent antioxidant and antibacterial activity. These biogenic LBOE-AuNPs showed 91% dye degradation efficiency during catalytic reduction activity on BTB dye, demonstrating their versatility as options for heterogeneous catalysis