Faber polynomial coefficient estimates for analytic bi-close-to-convex functions

Using the Faber polynomials, we obtain coefficient expansions for analytic bi-close-to-convex functions and determine coefficient estimates for such functions. We also demonstrate the unpredictable behavior of the early coefficients of subclasses of bi-univalent functions. A function is said to be bi-univalent in a domain if both the function and its inverse map are univalent there.     

Accessible single-valued neutrosophic graphs

This paper derived single-valued neutrosophic graphs from single-valued neutrosophic hypergraphs via strong equivalence relation. We show that any weak single-valued neutrosophic graph is a derived single-valued neutrosophic graph and any linear weak single-valued neutrosophic tree is an extendable linear single-valued neutrosophic tree.     

Surface modified SPIONs‐Cr(VI) ions‐immobilized organic‐inorganic hybrid as a magnetically recyclable nanocatalyst for rapid synthesis of polyhydroquinolines under solvent‐free conditions at room temperature

In this work, a magnetic hybrid dichromate nanocomposite with triphenylphosphine surface modified superparamagnetic iron oxide nanoparticles (SPIONs) as a recyclable nanocatalyst was designed, prepared and characterized by Fourier transform infrared spectroscopy (FT‐IR) spectra, X‐ray diffraction (XRD) pattern analysis, vibrating sample magnetometer (VSM) curves, X‐ray fluorescence (XRF) analysis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images and dynamic light scattering (DLS) analysis. Then, it was used in a green and efficient procedure for one‐pot multicomponent synthesis of polyhydroquinoline derivatives by the condensation of aldehydes, dimedone or 1,3‐cyclohexadione, ethyl acetoacetate and ammonium acetate. This protocol includes some new and exceptional advantages such as short reaction times, low catalyst loading, high yields, solvent‐free and room temperature conditions, easy separation and reusability of the catalyst.     

Kinetics Study of the Thermal Decomposition of Post-consumer Poly(Ethylene Terephthalate) in an Argon Atmosphere

The thermal decomposition of post-consumer samples of a carbonated water bottle made of poly(ethylene terephthalate), PC-PET, was examined by linear temperature programing under an argon atmosphere to determine its mass loss kinetics. A simple kinetic model, called the first order pseudo single-component model, was used. The total weight-loss of each sample assumed to be in two periods, with each period corresponding to a one step decomposition of the PC-PET to volatiles. Three methods for determining the kinetic parameters by thermal gravimetric analysis were examined: differential analysis at a constant heating rate (differential), temperatures of a given conversion at a number of heating rates (isoconversional), and the maximum rate at multiple heating rates (peak temperature). The latter two multiple heating rates methods results were comparable to each other but they were not in agreement with the results from the differential method. The results of the differential method were insensitive to the heating rate and consistent with kinetics data reported in the literature for PET.     

Recent advances in synthesis of 2-pyridones: a key heterocycle is revisited

Owing to the versatile applications in different areas including biology, natural compounds, dyes, and fluorescent materials, the synthesis of 2-pyridone compounds is an important research field and has attracted a great deal of attention. In this review, 2-pyridones new synthetic methods are classified to tree classes including reactions based on pyridine rings, cyclization, and cycloaddition reactions.     

A Rapid and Sensitive LC–MS Method for Determination of Ezetimibe Concentration in Human Plasma: Application to a Bioequivalence Study

A selective and highly sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been developed for determination of ezetimibe concentrations in human plasma. Ezetimibe was extracted from plasma with ethyl acetate followed by evaporation of the organic layer and, then, reconstitution of the residue in mobile phase before injection to chromatograph. The mobile phase consisted of acetonitrile-ammonium acetate (10 mM, pH 3.0), 75:25 (v/v). An aliquot of 10 μL was chromatographically analyzed on a prepacked Zorbax XDB-ODS C₁₈ column (2.1 × 100 mm, 3.5 micron). Detection of analytes was achieved by mass spectrometry with atmospheric pressure chemical ionization (APCI) interface in the negative ion mode operated under the multiple-reaction monitoring mode (m/z transition: ezetimibe 408–271). Standard curves were linear (r = 0.998) over the wide ezetimibe concentration range of 0.05–30.0 ng mL⁻¹ with acceptable accuracy and precision. The limit of detection was 0.02 ng mL⁻¹. The validated LC–APCI–MS method has been used successfully throughout a bioequivalence study on an ezetimibe generic product in 24 healthy male volunteers.

     

New materials based on thiazolothiazole and thiophene candidates for optoelectronic device applications: theoretical investigations

We report theoretical analysis on the geometries and electronic properties of new conjugated compounds based on thiazolothiazole synthesized by Ando et al. (Synth. Met., 156:327 [13]). The theoretical ground-state geometry and electronic structure of the studied molecules were investigated by the density functional theory (DFT) method at Becke’s three-parameter functional and Lee–Yang–Parr functional (B3LYP) level with 6-31G(d,p) basis set. The effects of the ring structure and the substituents on the geometries and electronic properties of these materials are discussed to investigate the relationship between molecular structure and optoelectronic properties. This investigation was used to drive further syntheses towards compounds more useful as active optoelectronic materials. Theoretical knowledge of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the components is basic in studying organic solar cells, so the HOMO, LUMO, and gap energy V _oc (open-circuit voltage) of the studied compounds are calculated and discussed. These properties suggest these materials as good candidates for use in organic dye-sensitized solar cells.     

The effect of target rotation rate on structural and morphological properties of thin garnet films fabricated by pulsed laser deposition

The effect of target rotation rate on the structural and morphological properties of pulsed laser deposition grown Bi:YIG garnets is investigated. The rotation rate dependence of the surface morphology and magnetic properties of the thin films were studied using atomic force microscopy combined with a magneto-optical measurement setup. The results show that decrease in the target rotation rate can also increase the roughness, the index of refraction, and the surface skewness and can decrease Faraday rotation by an order of magnitude.     

Solubility prediction of deferiprone in N-methyl-2-pyrrolidone + ethanol mixtures at various temperatures using a minimum number of experimental data

Experimental solubility of deferiprone (DFP) in N-methyl-2-pyrrolidone (NMP) + ethanol (EtOH) mixtures at 293.2, 298.2, 303.2 and 308.2 K was determined and mathematically represented using various models. The trained versions of the van’t Hoff equation, its combined version with log-linear model, Jouyban–Acree model and a combination of van’t Hoff + Jouyban–Acree model were reported to simulate DFP solubility in the binary mixture compositions at various temperatures. The mean percentage deviation (MPD) was used as an accuracy criterion. The obtained overall MPDs for back-calculated and predicted solubility of DFP in NMP + EtOH mixtures varied from 1.1% to 3.2% and 2.6% to 6.6%, respectively. Some of apparent thermodynamic quantities for the dissolution processes of DFP are also reported.