Comments on the effect of liquid layering on the thermal conductivity of nanofluids

This article provides critical examinations of two mathematical models that have been developed in recent years to describe the impact of nano-layering on the enhancement of the effective thermal conductivity of nanofluids. Discrepancy between the two models is found to be an artefact of an incorrect derivation used in one of the models. With correct formulation, both models predict effective thermal conductivity enhancements that are not significantly greater than those predicted by classical Maxwell theory. This study indicates that nano-layering by itself is unable to account for the effective thermal conductivity enhancements observed in nanofluids.     

Uniqueness of the entanglement measure for bipartite pure states and thermodynamics

We apply the axiomatic approach to thermodynamics presented by Giles to derive a unique measure of entanglement for bipartite pure states. This implies that local manipulations of entanglement in quantum information theory and adiabatic transformations of states in thermodynamics have the same underlying mathematical structure. We discuss possible extensions of our results to mixed and multipartite states.     

CuI-catalyzed Coupling Reactions of Aryl Iodides with Amides Using L-Proline and KF/Al2O3

An efficient experimentally simple and inexpensive catalyst system for the selective amidation of aryl iodides using 15 mol% of CuI as catalyst, 15 mol% of L-proline as ligand and KF/Al2O3 as a base in toluene is described.     

Novel amide derivatives of 3-phenylglutaric acid as potent soluble epoxide hydrolase inhibitors

Molecular Diversity - Soluble epoxide hydrolase (sEH) enzyme plays an important role in the metabolism of endogenous chemical mediators, epoxyeicosatrienoic acids, which are involved in the...     

Recent strategies in the synthesis of thiophene derivatives: highlights from the 2012–2020 literature

Molecular Diversity - Thiophene-based analogs have been fascinated by a growing number of scientists as a potential class of biologically active compounds. Furthermore, they play a vital role for...     

Facile synthesis of novel dihydroquinoline-3,3-dicarbonitriles in the presence of glacial acetic acid as a catalyst under solvent-free conditions

A series of novel dihydroquinoline derivatives were synthesized using malononitrile, 2-aminobenzoic acid, and benzaldehydes in the presence of a catalytic amount of acetic acid, without the use of any additional cocatalyst, under solvent-free conditions. The reaction is characterized by high efficiency, easy workup, simple purification of the products, and availability of catalyst.     

DFT, ab initio, NMR, and NBO analyses of N-substituted hydrazino acetamides: Experimental vs theoretical values

We studied the DFT (B3LYP) and HF at 6-31+G/6-31+G^∗∗ levels of theory in order to throw light on the conformation, structure, intramolecular hydrogen bond network, as well as proton and nitrogen NMR (GIAO method) of a series of model primary amides in the gas phase and/or in solution (chloroform, methanol, water, dimethyl sulfoxide, and heptane). In this manner, it was possible to show that the amidic group of these model compounds acts as the H-bond donor and interacts with two different H-bond acceptors, thus stabilizing the C₈ pseudocycle. The study was conducted to gain a better understanding of the conformation (both experimentally and theoretically) adopted by hydrazino acetamides (model compounds for aza-β³-peptides). In the light of this, we were able to explain why aza-β³-peptides develop a different H-bond network in comparison to their isosteric β³-peptide analogues (an extension of the β-peptide concept).     

Modeling and optimizing of sonochemical degradation of Basic Blue 41 via response surface methodology

The nanocatalyst-assisted sonodegradation of Basic Blue 41 (BB41) dye in aqueous medium was modeled and optimized using response surface method (RSM) based on Box-Behnken design. The studied variables included pH, initial dye concentration, H₂O₂ concentration and sonolysis time while each factor varied at three levels: Low level (−1), Medium level (0) and High level (+1). The ultrasound -assisted degradation was well described by developing quadratic model with correlation value squared (R²) of 0.9114. Factor effects along with interaction effects were evaluated. The graphical optimization step was conducted to achieve the best experimental condition in dye removal. pH, H₂O₂ concentration and initial dye concentration of the reaction were investigated. It was recognized that at lower pH values the dye removal rate decreased. However, dye removal rate increased (82.5%) by increasing the concentration of H₂O₂ and by lowering the initial dye concentration.