Peristaltic motion of micropolar fluid in circular cylindrical tubes: Effect of wall properties

In this paper, peristaltic motion of micropolar fluid in a circular cylindrical flexible tube with viscoelastic or elastic wall properties has been considered. A finite difference scheme is developed to solve the governing equations of motion resulting from a perturbation technique for small values of amplitude ratio. The time mean axial velocity profiles are presented for the case of free pumping and analysed to observe the influence of wall properties for various values of micropolar fluid parameters. In the case of viscoelastic wall, the effect of viscous damping on mean flow reversal at the boundary is seen.     

Sequence spaces of fuzzy real numbers defined by Orlicz functions

In this article we study different properties of convergent, null and bounded sequence spaces of fuzzy real numbers defined by an Orlicz function, like completeness, solidness, symmetricity, convergence free etc. We prove some inclusion results, too. The work of the first author was carried under University Grants Commission of India project No.-F. No. 30-240/2004 (RS).     

Applications of Carbon Dots (CDs) in Latent Fingerprints Imaging

Carbon dots (CDs), a new member of the carbon-based material family, possess unique properties, such as high fluorescence, non-toxicity, eco-friendliness, stability and cost-effectiveness. These properties helped CDs to receive tremendous attention in various fields, namely, biological, opto-electronic, bio-imaging and energy-related applications. Although CDs are widely explored in bio-imaging and bio-sensing applications, their effectiveness in forensic science and technology is comparatively new. In this review, applications of CDs pertaining to latent FPs recovery since 2015 to 2020 is summarized comprehensively.     

Dielectric relaxation and conductivity studies on (PEO:LiClO4) polymer electrolyte with added ionic liquid [BMIM][PF6]: Evidence of ion–ion interaction

Polymer electrolytes, (PEO:LiClO₄)+x IL (1‐Buty‐3‐methylimidazolium hexafluorophosphate) with varying concentration of IL; x = 0,5,10,15,20 wt % have been prepared by solution cast technique and characterized by X‐Ray diffraction, differential scanning calorimetery, FTIR, conductivity and dielectric relaxation measurements in the frequency range of 100 Hz–5 MHz. Temperature dependence of relaxation frequency and conductivity were found to be typical of thermally activated process both at T > T_m and T < T_m. Composition dependence of conductivity, dielectric relaxation, and degree of crystallinity has also been studied. On addition of IL, the degree of crystallinity after a decrease at 5 wt % IL increases slightly at 10 wt % and then finally decreasing. Variation of conductivity and relaxation frequency with composition could only be partly explained on the basis of variation of degree of crystallinity. An additional feature of ion–ion interaction (contact ion pair formation between IL or salt cations and their associated anions) has been invoked which was supported by FTIR studies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

In silico fight against novel coronavirus by finding chromone derivatives as inhibitor of coronavirus main proteases enzyme

Structural Chemistry - Novel coronavirus, 2019-nCoV is a danger to the world and is spreading rapidly. Very little structural information about 2019-nCoV make this situation more difficult for drug...     

Phenylacetylene: A Hydrogen Bonding Chameleon

Molecules with multiple hydrogen bonding sites offer the opportunity to investigate competitive hydrogen bonding. Such an investigation can become quite interesting, particularly when the molecule of interest has neither lone‐pair electrons nor strongly acidic/basic groups. Phenylacetylene is one such molecule with three hydrogen bonding sites that cannot be ranked into any known hierarchical pattern. Herein we review the structures of several binary complexes of phenylacetylene investigated using infrared optical double‐resonance spectroscopy in combination with high‐level ab initio methods. The diversity of intermolecular structures formed by phenylacetylene with various reagents is remarkable. The nature of intermolecular interaction with various reagents is the result of a subtle balance between various configurations and competition between the electrostatic and dispersion energy terms, while trying to maximize the total interaction strength.     

Facile Synthesis of Metal–Organic Framework (ZIF-11) and Ag NPs Encapsulated-ZIF-11 Composite as an Effective Heterogeneous Catalyst for Photodegradation of Methylene Blue

Facile synthesis of metal–organic framework based on zeolitic imidazolate (ZIF-11) has been optimized to get a material with rho topology. For the first time AgNPs in various dosing amounts (using 150, 300 and 500 μL of its suspension in methanol) have been successfully encapsulated within ZIF-11 matrix at room temperature using binary solvent (methanol and toluene) yielding novel multi-core-shell AgNPs@ZIF-11 (AZ1, AZ2 and AZ3) composites. Encapsulation of AgNPs (particle size: 11.76 ± 2.3 nm) has been confirmed by TEM and ultraviolet diffuse reflectance spectroscopic (UV-DRS) analysis. The lowering of band gap of ZIF-11 from 4.36 to 4.21 eV indicates the micro-environment of AgNPs within ZIF-11 framework, which has also been ensured by XPS analysis. ZIF-11 and AgNPs@ZIF-11 composites are highly stable up to 500 °C under air and N₂ atmosphere. It has been found that AZ1 composite exhibits excellent photocatalytic activity (almost 100% degradation) toward MB (1.6 mg/L) at pH ≥ 8. Further, various factors such as loading amount of AgNPs (150, 300 and 500 μL suspension in methanol), amount of catalysts (5 mg, 10 mg and 15 mg) and concentration (1.6 mg L⁻¹, 3.19 mg L⁻¹ and 6.38 mg L⁻¹) of methylene blue (MB) dye during photodegradation experiments have been investigated. The capacious achievement of AZ1 composite is its reusability and recyclability; it can be reutilized up to three cycles with the same efficiency (100%) while under fourth and fifth cycle, it can degrade off 92.12% and 72.75% MB, respectively. AgNPs may act as a mediator to promote the quick transfer of photo-induced electrons and electron–hole pairs separation in ZIF-11. This work opens a new type of easily fabricated core-shell composites utilizing ZIF-11 for wastewater remediation process.