Efficient Method for Oxidation of Ketones to Esters with 4-Aminoperoxybenzoic Acid Supported On Silica Gel

4-Aminoperoxybenzoic acid supported on silica gel was found to be a versatile and efficient oxidant for the oxidation of ketones to esters.     

One-pot synthesis of novel polysubstituted furopyran derivatives via pseudo seven-component reaction (6 + 1) of isocyanides with bisarylidene Meldrum's acid containing ether groups

In the present study, a group of polysubstituted furopyran derivatives possessing ether spacer groups were synthesized under good-to-exceptional yields via cycloaddition of bisarylidene Meldrum's acid derivatives (1 mmol) with isocyanides (6 mmol) within dichloromethane (CH₂Cl₂) for 3 to6 hours at room temperature with no assistance from any type of catalysts. The structure of the products was then confirmed by Fourier Transform-infrared spectroscopy, ¹H-nuclear magnetic resonance spectroscopy, ¹³C-nuclear magnetic resonance spectroscopy, and elemental analysis. Moreover, the 5c , 5d , and 5f compounds exhibited favorable pharmaceutical behavior as antibacterial.     

Microwave‐associate synthesis of Co3O4 nanoparticles as an effcient nanocatalyst for the synthesis of arylidene barbituric and Meldrum's acid derivatives in green media

In this study, Co₃O₄ nanocatalysts were constructed in environmentally appropriate conditions using controlled, effective, and facile microwave method. The final nanostructures were characterized by SEM, XRD, and TEM analyses. The products had a small size distribution, homogeneous morphology, and crystallographic structures associated with the formation of Co₃O₄ nanostructures. Moreover, EDS mapping analysis confirmed the existence of Co and O elements in the final structure, and the magnetic properties of the samples were investigated by VSM. The application of this nanostructure in a catalytic process was further examined, and the results suggested that it could be used as a novel candidate for the synthesis of arylidene barbituric and Meldrum^,s acid through Knoevenagel condensation of aldehydes by barbituric and Meldrum^,s acid in aqueous media. The high yield of these nanocatalysts would be justified by the nature of the nanostructure as well as the experimental procedure developed in this study, which affected the physicochemical features of the products.     

Highly Regioselective Ring Opening of Epoxides with Thiols Catalyzed by SbCl3 Under Solvent-Free Conditions

The ring-opening reaction of epoxides with thiols by SbCl ₃ supported on Kieselguhr under solvent-free conditions, afforded high yields of β-hydroxy sulfides. Nucleophilic attack of the thiols occurs regioselectively at the less hindered side of the epoxides.     

Theoretical investigation of functionalized fullerene nano carrier drug delivery of fluoxetine

In recent years, fullerene nanoparticles have received extensive attention due to their unique physical and chemical properties. Properly modified fullerene nanoparticles have excellent biocompatibility and significant anti-tumor activity and anti-depression, which makes them have broad application prospects in the field of cancer anti-depression. The present study used the density functional theory (DFT) calculations to perform a theoretical examination of the interaction of fluoxetine (F) as medicine with the functionalized fullerene O and NO (F–O and F–NO surface in gas phase physiological media. According to DFT calculations, adsorption energies were ?3396.6350645, ?3540.2952907, ?6778.526894, and ?6952.251487 kJ for F/P complexes (fullerene O and NO (F–O and F–NO surface) respectively, proposing the possibility of the adsorption process of F molecule onto the fullerene surface concerning the energetic perspective. Calculations of electronic parameters aimed at determining the molecule's reactivity. Bandgap of F–O and F–NO were 0.03715, 0.04328 respectively, by this value we can recognize the reactivity of complexes.     

On the stability of a radical cubic functional equation in quasi-$${\beta}$$-spaces

In this paper, we introduce and solve the radical cubic functional equation

$$f\left({\sqrt[3]{x^{3} + y^{3}}}\right)= f(x) + f(y).$$

We also establish stability in quasi-\({\beta}\)-Banach spaces, and then the stability by using subadditive and subquadratic functions for the radical cubic functional equation in (\({\beta}\), p)-Banach spaces is given.

     

Hermite–Hadamard Type Inequalities for Functions Whose Derivatives are Operator Convex

In this paper, we shall offer two inequalities for differentiable mappings which the induced maps by them on the set of Hermitian operators are operator convex. we establish some estimates of the right hand side of a Hermite–Hadamard type inequality in which such functions are involved.     

Characterizing the Role of Shale Geometry and Connate Water Saturation on Performance of Polymer Flooding in Heavy Oil Reservoirs: Experimental Observations and Numerical Simulations

Many heavy oil reservoirs contain discontinuous shales which act as barriers or baffles to flow. However, there is a lack of fundamental understanding about how the shale geometrical characteristics affect the reservoir performance, especially during polymer flooding of heavy oils. In this study, a series of polymer injection processes have been performed on five-spot glass micromodels with different shale geometrical characteristics that are initially saturated with the heavy oil. The available geological characteristics from one of the Iranian oilfields were considered for the construction of the flow patterns by using a controlled-laser technology. Oil recoveries as a function of pore volumes of injected fluid were determined from analysis of continuously recorded images during the experiments. We observed a clear bypassing of displacing fluid which results in premature breakthrough of injected fluid due to the shale streaks. Moreover, the results showed a decrease of oil recovery when shales’ orientation, length, spacing, distance of the shale from production well, and density of shales increased. In contrast, an increase of shale discontinuity or distance of the shale streak from the injection well increased oil recovery. The obtained experimental data have also been used for developing and validating a numerical model where good matching performance has been observed between our experimental observations and simulation results. Finally, the role of connate water saturation during polymer flooding in systems containing flow barriers has been illustrated using pore level visualizations. The microscopic observations confirmed that besides the effect of shale streaks as heterogeneity in porous medium, when connate water is present, the trapped water demonstrates another source of disturbance and causes additional perturbations to the displacement interface leading to more irregular fingering patterns especially behind the shale streaks and also causes a reduction of ultimate oil recovery. This study reveals the application of glass micromodel experiments for studying the effects of barriers on oil recovery and flow patterns during EOR processes and also may provide a set of benchmark data for recovery of oil by immiscible polymer flood around discontinuous shales.     

Holographic conductivity of holographic superconductors with higher-order corrections

We analytically and numerically disclose the effects of the higher-order correction terms in the gravity and in the gauge field on the properties of s-wave holographic superconductors. On the gravity side, we consider the higher curvature Gauss–Bonnet corrections and on the gauge field side, we add a quadratic correction term to the Maxwell Lagrangian. We show that, for this system, one can still obtain an analytical relation between the critical temperature and the charge density. We also calculate the critical exponent and the condensation value both analytically and numerically. We use a variational method, based on the Sturm–Liouville eigenvalue problem for our analytical study, as well as a numerical shooting method in order to compare with our analytical results. For a fixed value of the Gauss–Bonnet parameter, we observe that the critical temperature decreases with increasing the nonlinearity of the gauge field. This implies that the nonlinear correction term to the Maxwell electrodynamics makes the condensation harder. We also study the holographic conductivity of the system and disclose the effects of the Gauss–Bonnet and nonlinear parameters \(\alpha \) and b on the superconducting gap. We observe that, for various values of \(\alpha \) and b, the real part of the conductivity is proportional to the frequency per temperature, \(\omega /T\), as the frequency is large enough. Besides, the conductivity has a minimum in the imaginary part which is shifted toward greater frequency with decreasing temperature.