Showing papers by "Bharathiar University published in 2022"

Plant growth promoting bacteria improve growth and phytostabilization potential of Zea mays under chromium and drought stress by altering photosynthetic and antioxidant responses

Abstract: Drought in heavy metal polluted arid and semiarid regions severely inhibits the plant growth and phytoremediation potential by affecting photosynthesis, antioxidant defense mechanism, and other biochemical processes. In the present study, we explored the role of plant growth-promoting bacteria (PGPB) on Zea mays growth and phytoremediation efficiency in Chromium (Cr) contaminated soils under drought stress by assessing plant stress tolerance, photosynthetic gas exchange activities, chlorophyll fluorescence, and Cr accumulation. Two efficient Cr and drought resistant PGPB with the potential to reduce Cr(VI) to Cr(III) and produce plant growth-promoting metabolites even under Cr, drought, or Cr+drought stress conditions were isolated and identified as Providencia sp. (TCR05) and Proteus mirabilis (TCR20). In pot experiments, the inoculation of TCR05 and TCR20 increased the plant growth, pigments, protein, phenolics, and relative water content and decreased the lipid peroxidation, proline, and superoxide dismutase activity under Cr, drought, or Cr+drought conditions. Irrespective of stress treatment, TCR05 and TCR20 also improved plant photosynthetic efficiency by increasing the CO 2 assimilation rate, stomatal conductance to water vapor, transpiration rate, maximum quantum efficiency of PSII, actual quantum efficiency of PSII, electron transport rate, photochemical quenching, reducing the internal CO 2 concentration and non-photochemical quenching. Besides, the PGPB decreased the translocation of Cr through immobilization of Cr in root. These results denoted that strains TCR05 and TCR20 could be a capable bio-inoculant for improving plant growth and phytostabilization practices in Cr contaminated sites even under water-limited conditions. • Potential Cr(VI) reducing MST-PGPB strains TCR05 and TCR20 were isolated. • MST-PGPB enhanced stress tolerance of Z. mays under combined stress conditions. • PGPB inoculation improved the PSII performance of Z. mays under combined stresses. • PGPB inoculation improved Cr phytostabilization under combined stress conditions.

Complex Pythagorean fuzzy einstein aggregation operators in selecting the best breed of Horsegram

Abstract: The intention of this article is to develop and introduce an extension from Pythagorean fuzzy sets (PFS) to complex Pythagorean fuzzy sets (CPFS) related to weighted aggregated functions involving Einstein operator. The main purpose of such an extension is that the periodicity of the terms can also be taken into account during the aggregation operation. The prime goal of this article is to formulate the aggregation operators such as the complex Pythagorean fuzzy Einstein weighted arithmetic aggregating operator (CPFEWA), complex Pythagorean fuzzy Einstein ordered weighted arithmetic aggregating operator (CPFEOWA), complex Pythagorean fuzzy Einstein weighted geometric aggregating operator (CPFEWG) and complex Pythagorean fuzzy Einstein weighted ordered geometric aggregating operator (CPFEOWG) and to detail few of it’s prime properties. Finally, to express the effectiveness of the proposed approach and to elucidate the purpose of these operators, a multi criteria decision making problem to select the best breed of Horsegram is considered using the data given by the expert and the result is compared with the results of the existing operators.

Surface tuned polyethersulfone membrane using an iron oxide functionalized halloysite nanocomposite for enhanced humic acid removal

Abstract: Nanomodification of ultrafiltration (UF) membranes has been shown to be a simple and efficient technique for the preparation of high-performance membranes. In this work, an iron oxide functionalized halloysite nanoclay (Fe-HNC) nanocomposite was prepared and used as a nanofiller for polyethersulfone (PES) membranes. The effect of Fe-HNC concentration on the filtration performance of the membrane was investigated by varying the nanocomposite dosage (0-0.5 wt %) in the casting dope. Various characterization studies showed that the incorporation of Fe-HNC nanocomposites improved the membrane morphology and enhanced the surface properties, thermal stability, mechanical strength, hydrophilicity, and porosity. The permeability to pure water and filtration of humic acid (HA) were significantly improved by incorporating Fe-HNC into the PES membranes. The membrane with Fe-HNC loading of 0.1 wt % exhibited the highest pure water permeability (174.3 L/(m2 h bar)) and removal of HA (90.1 %), which were 1.8 times and 29 % higher, respectively than the pristine PES membrane. Moreover, fouling studies showed the enhanced antifouling ability of the Fe-HNC nanocomposites modified PES membranes, especially against irreversible fouling. Continuous membrane regeneration-based fouling removal studies from HA showed that the PES/0.1 wt % Fe-HNC membrane exhibited a high fouling recovery of 70.4 % with very low reversible and irreversible fouling resistance of 9.61 % and 14.78 %, respectively, compared to the pristine PES membrane (fouling recovery: 40.4 %; reversible fouling: 21.7 %; irreversible fouling: 20.1 %). Overall, the Fe-HNC nanocomposite proved to be an effective nanomodifier for improving the permeability of PES membranes and the antifouling ability to treat HA polluted aqueous streams.

Design of rutile nanospheres decorated rGO/β-CD nanoflakes composite: A sustainable electrocatalyst for effective non-enzymatic determination of L-Tyrosine

Abstract: A novel and facile electrochemical sensing device has fabricated based on TiO2@rGO/β-CD nanocomposite altered GCE for trace-level detection of L-Tyrosine. The crystalline nature, functional groups, shape morphology of nanocomposite were confirmed using various characterization techniques. The FE-SEM results expose TiO2 nanospheres were strongly bind with flake-like rGO/β-CD composite. The layer-like morphology of GO was modified to a flake-like structure with reduction in occurrence of dextrin linkages attached to GO layers with host-guest supramolecular interaction. These features further confirmed using HR-TEM analysis. The TiO2 nanospheres exist in flake-like surface of rGO/β-CD composite that significantly enhanced the active superficial area, conductivity of nanocomposite. The fabricated electrode shows superior and improved electrocatalytic oxidation, high sensitivity and low detection limits towards L-Tyr. It was ascribed to synergistic recombination between the edge planes of carbon-based materials and TiO2 exist in nanocomposite. The TiO2@rGO/β-CD modified GCE response over wide dynamic range (0.01–1920 μM), LOD (7.6 nM) for L-Tyr detection. Additionally, it displayed notable repeatability, reproducibility and storage stability. Moreover, the practicability of the proposed sensor in Apple juice, Tyr tablet and recovery results satisfactory. All strategies proposed TiO2@rGO/β-CD nanocomposite as sustainable electrocatalyst that could be explored as excellent candidate for detecting the L-Tyrosine in real sample analysis.

Design of rutile nanospheres decorated rGO/β-CD nanoflakes composite: A sustainable electrocatalyst for effective non-enzymatic determination of L-Tyrosine

Abstract: A novel and facile electrochemical sensing device has fabricated based on TiO2@rGO/β-CD nanocomposite altered GCE for trace-level detection of L -Tyrosine. The crystalline nature, functional groups, shape morphology of nanocomposite were confirmed using various characterization techniques. The FE-SEM results expose TiO2 nanospheres were strongly bind with flake-like rGO/β-CD composite. The layer-like morphology of GO was modified to a flake-like structure with reduction in occurrence of dextrin linkages attached to GO layers with host-guest supramolecular interaction. These features further confirmed using HR-TEM analysis. The TiO2 nanospheres exist in flake-like surface of rGO/β-CD composite that significantly enhanced the active superficial area, conductivity of nanocomposite. The fabricated electrode shows superior and improved electrocatalytic oxidation, high sensitivity and low detection limits towards L -Tyr. It was ascribed to synergistic recombination between the edge planes of carbon-based materials and TiO2 exist in nanocomposite. The TiO2@rGO/β-CD modified GCE response over wide dynamic range (0.01–1920 μM), LOD (7.6 nM) for L -Tyr detection. Additionally, it displayed notable repeatability, reproducibility and storage stability. Moreover, the practicability of the proposed sensor in Apple juice, Tyr tablet and recovery results satisfactory. All strategies proposed TiO2@rGO/β-CD nanocomposite as sustainable electrocatalyst that could be explored as excellent candidate for detecting the L -Tyrosine in real sample analysis.