Biosynthesis of zinc oxide nanoparticles using Euphorbia milii leaf constituents: Characterization and improved photocatalytic degradation of methylene blue dye under natural sunlight

A facile biosynthesis route was followed to prepare zinc oxide nanoparticles (ZnO NPs) using Euphorbia milii (E. milii) leaf constituents. The SEM images exhibited presence of spherical ZnO NPs and the corresponding TEM images disclosed monodisperse nature of the ZnO NPs with diameter ranges between 12 and 20 nm. The Brunauer–Emmett–Teller (BET) analysis revealed that the ZnO NPs have specific surface area of 20.46 m²/g with pore diameter of 2 nm–10 nm and pore volume of 0.908 cm³/g. The EDAX spectrum exemplified the existence of Zn and O elements and non-appearance of impurities that confirmed pristine nature of the ZnO NPs. The XRD pattern indicated crystalline peaks corresponding to hexagonal wurtzite structured ZnO with an average crystallite size of 16.11 nm. The FTIR spectrum displayed strong absorption bands at 512 and 534 cm^?1 related to ZnO. The photocatalytic action of ZnO NPs exhibited noteworthy degradation of methylene blue dye under natural sunlight illumination. The maximum degradation efficiency achieved was 98.17% at an illumination period of 50 min. The reusability study proved considerable photostability of the ZnO NPs during photocatalytic experiments. These findings suggest that the E. milii leaf constituents can be utilized as suitable biological source to synthesis ZnO NPs for photocatalytic applications.     

Thermophysical properties of neat and radiolytically degraded acidic extractants present in room temperature ionic liquid

In the present work, radon concentrations were measured in surface and underground water samples in Faridabad District of Southern Haryana, India using an active radon monitor based on alpha scintillation technique and results have been inter-compared. The average radon concentration in the underground water samples was observed to be 4 times higher than in the surface water samples. The estimated annual effective dose varied from 5.7 to 58.5 μSvy^?1 with an average of 24.2 μSvy^?1 for underground water samples and 1.1 to 12.5 μSvy^?1 with an average of 6.7 μSvy^?1 for surface water samples. The estimated annual effective dose for both type of samples was found to be less than 0.1 mSvy^?1, which is the safe limit as suggested by World Health Organisation and EU Council.

     

Finite element computations of viscoelastic two-phase flows using local projection stabilization

A three-field local projection stabilized (LPS) finite element method is developed for computations of a three-dimensional axisymmetric buoyancy driven liquid drop rising in a liquid column where one of the liquid is viscoelastic. The two-phase flow is described by the time-dependent incompressible Navier-Stokes equations, whereas the viscoelasticity is modeled by the Giesekus constitutive equation in a time-dependent domain. The arbitrary Lagrangian-Eulerian (ALE) formulation with finite elements is used to solve the governing equations in the time-dependent domain. Interface-resolved moving meshes in ALE allows to incorporate the interfacial tension force and jumps in the material parameters accurately. A one-level LPS based on an enriched approximation space and a discontinuous projection space is used to stabilize the numerical scheme. A comprehensive numerical investigation is performed for a Newtonian drop rising in a viscoelastic fluid column and a viscoelastic drop rising in a Newtonian fluid column. The influence of the viscosity ratio, Newtonian solvent ratio, Giesekus mobility factor, and the Eötvös number on the drop dynamics are analyzed. The numerical study shows that beyond a critical Capillary number, a Newtonian drop rising in a viscoelastic fluid column experiences an extended trailing edge with a cusp-like shape and also exhibits a negative wake phenomena. However, a viscoelastic drop rising in a Newtonian fluid column develops an indentation around the rear stagnation point with a dimpled shape.     

Hellmann–Feynman connection for the relative Fisher information

The (i) reciprocity relations for the relative Fisher information (RFI, hereafter) and (ii) a generalized RFI–Euler theorem are self-consistently derived from the Hellmann–Feynman theorem. These new reciprocity relations generalize the RFI–Euler theorem and constitute the basis for building up a mathematical Legendre transform structure (LTS, hereafter), akin to that of thermodynamics, that underlies the RFI scenario. This demonstrates the possibility of translating the entire mathematical structure of thermodynamics into a RFI-based theoretical framework. Virial theorems play a prominent role in this endeavor, as a Schrödinger-like equation can be associated to the RFI. Lagrange multipliers are determined invoking the RFI–LTS link and the quantum mechanical virial theorem. An appropriate ansatz allows for the inference of probability density functions (pdf’s, hereafter) and energy-eigenvalues of the above mentioned Schrödinger-like equation. The energy-eigenvalues obtained here via inference are benchmarked against established theoretical and numerical results. A principled theoretical basis to reconstruct the RFI-framework from the FIM framework is established. Numerical examples for exemplary cases are provided.     

Gastroprotective potentials of the ethanolic extract of Mukia maderaspatana against indomethacin-induced gastric ulcer in rats

This study investigated the protective effects of the ethanolic extract of Mukia maderaspatana against indomethacin-induced gastric ulcer in rats. Gastric ulceration was induced by single intraperitoneal injection of indomethacin (30 mg/kg b.wt.). M. maderaspatana extract produced significant reduction in gastric mucosal lesions, malondialdehyde and serum tumour necrosis factor-α associated with a significant increase in gastric juice mucin content and gastric mucosal catalase, nitric oxide and prostaglandin E2 levels. The volume and acidity of the gastric juice decreased in pretreated rats. The plant extract was evaluated in the gastric juice of rats, untreated has showed near normal levels in pretreated rats. The M. maderaspatana was able to decrease acidity and increase the mucosal defence in the gastric area, therefore justifying its use as an antiulcerogenic agent. Ranitidine significantly increased pH value and decreased pepsin activity and gastric juice free and total acidity. The anti-ulcer effect was further confirmed histologically.     

Platinum/carbon black composites as counter electrodes for high-performance dye-sensitized solar cells

Journal of Solid State Electrochemistry - Low-cost counter electrodes for dye-sensitized solar cells (DSSCs) are prepared using platinum/carbon black (Pt/CB) composites via a spin-coating process....     

Piperidine‐mediated synthesis of thiazolyl chalcones and their derivatives as potent antimicrobial agents

A series of new thiazolyl chalcones, 1‐[2‐amino‐4‐methyl‐1, 3‐thiazol‐5‐yl]‐3‐aryl‐prop‐2‐en‐1‐one were prepared by piperidine mediated Claisen‐Schmidt condensation of thiazolyl ketone with substituted aromatic aldehyde. These chalcones on cyclization gave 2‐amino‐6‐(2‐amino‐4‐methyl‐1,3‐thiazol‐5‐yl)‐4‐aryl‐4H‐pyridine‐3‐carbonitrile and 2‐amino‐6‐(2‐amino‐4‐methyl‐1,3‐thiazol‐5‐yl)‐4‐aryl‐4H‐pyran‐3‐carbonitrile. The results showed that this skeletal framework exhibited marked potency as antimicrobial agents. The most active antibacterial agent was 2‐amino‐6‐(2‐amino‐4‐methyl‐1,3‐thiazol‐5‐yl)‐4‐(4‐chlorophenyl)‐4H‐pyran‐3‐carbonitrile while 2‐amino‐6‐(2‐amino‐4‐methyl‐1,3‐thiazol‐5‐yl)‐4‐(4‐methoyphenyl)‐4H‐pyran‐3‐carbonitrile appeared to be the most active antifungal agent. J. Heterocyclic Chem., (2011).     

Synthesis and in vitro antimicrobial studies of thiodihydropyrimidine derivatives

In the present study, a series of thiodihydropyrimidine derivatives were synthesized from different substituted aromatic aldehydes, ethyl acetoacetate, and urea/thiourea using a bimetallic TUD-1 catalyst. The structures of all the synthesized compounds were characterized by melting point determination, thin layer chromatography (TLC), infrared (IR), ¹HNMR, and ¹³C-NMR values. All the synthesized compounds were screened for their antimicrobial activities against two gram positive bacteria, two-gram negative bacteria, and two fungal strains.     

Metal‐Free Triplet Phosphors with High Emission Efficiency and High Tunability

Design of highly efficient phosphorescent emitters based on metal‐ and heavy atom‐free boron compounds has been demonstrated by taking advantage of the singlet fission process. The combination of a suitable molecular scaffold and appropriate electronic nature of the substituents has been utilized to tailor the phosphorescence emission properties in solution, neat solid, and in doped PMMA thin films.