Development and characterization of non-treated and chemically modified olive pomace biosorbents to remove Ce(III) ions from aqueous solutions

Journal of Radioanalytical and Nuclear Chemistry - In this study, low-cost olive pomace, which is a waste of olive mill, was chemically modified using different acids, characterized, and utilized...     

The diamagnetic susceptibility of hydrogenic donor in two-dimensional semiconductors with anisotropic effective mass of carriers

In this study, the effects of quantum confinement and effective mass anisotropy parameter on the diamagnetic susceptibility of a hydrogenic donor placed in GaAs, Si, and Ge quantum wells with infinite confinement potential are investigated in the effective mass and parabolic band approximations by using two and one parameter trial wave functions. It is observed that the diamagnetic susceptibility of a hydrogenic donor in anisotropic quantum wells is essentially equal to the transverse diamagnetic susceptibility part when well widths are larger than L > 100 Å, and the impurity is located at center. Moreover, a two parameter trial wave function model gives higher values of diamagnetic susceptibility, except for χ_z (GaAs).     

The Viscous Properties of Anionic/Cationic and Cationic/Nonionic Mixed Surfactant Systems

The behavior of mixed cationic/anionic and cationic/nonionic surfactants solutions have been studied by viscosimetry. The systems studied were sodium dodecyl sulfate (SDS)/cetyltrimethylammonium bromide (CTAB) and CTAB/Brij (polyoxyethylene lauryl ether, n = 10 and 23) in aqueous and sodium chloride solutions. The relative viscosity of single nonionic surfactant solutions is larger than that of SDS or CTAB solutions. It increases with the number of ethylene oxide groups. In the mixed systems, viscosity deviates from ideal behavior. The deviation results from electrostatic interactions. The surfactant mixture composition affects the self-assembled microstructure and rheology. A new mixed system that forms clear micellar solution above CMC was detected. In CTAB/Brij systems, the experimental data also deviate from ideal behavior due to mixed micelle formation and electroviscous effect. This effect is less pronounced than that of SDS/CTAB system and could be suppressed by adding an electrolyte (NaCl).     

Synthesis,characterization, antioxidant properties and DFT calculation of some new pyrimidine derivatives

Abstract

In this study, 5-benzoyl-4-(4-(methylthio)phenyl)-6-phenyl-1,2,3,4-tetrahydro-2-thioxo (1), oxo (2) and imino (3) pyrimidine derivatives were prepared via Multicomponent Cyclocondensation Reactions (MCRs). The compounds thiazolo[3,2-a]pyrimidin-3(5H)-one (4) and thiazin-4(6H)-one (5) were obtained via the reaction of compound 1 with bromoacetic acid and 3-bromopropionic acid, respectively. Structures were determined by using FT-IR, ¹H/¹³C NMR and elemental analyses. Also the compounds 4 and 5 were analyzed by X-ray single crystal analysis. All compounds were investigated as corrosion inhibitors using density functional theory (DFT) at the level of B3LYP/6-31G (d, p). According to the calculations, the compound 3 appears to be a good inhibitor for corrosion. On the other hand, total antioxidant properties were measured in vitro by DPPH^?, ABTS^?+ test, hemolysis of phenylhydrazine erythrocytes and metal chelating effect. The results were compared with standard antioxidants such as trolox and α-tocopherol. These data revealed that compounds 1, 2 and 5 are more active with respect to 3 and 4 in scavenging the radicals.     

The hydrostatic pressure and electric field effects on the normalized binding energy of hydrogenic impurity in a GaAs/AlAs spherical quantum dot

A theoretical study of combined effects of the hydrostatic pressure and the electric field on the subband ground state energy and on the normalized ground state binding energy of a hydrogenic donor impurity on center located in a GaAs/AlAs spherical quantum dot with fixed dot radius is presented. The study is performed in the framework of the effective mass and parabolic band approximations and using a variational procedure. As a key result, it may be possible to gather high resolution maps of electric field on the studied structure with described technique.     

Synthesis and spectral studies of pyranone derivative and its Cu(II), Co(II), Ni(II) and Zn(II) complexes

Under the thermolysis condition, 5-phenyl-2,3-dihydro-2,3-furandione (IV) in inert aprotic solvents as p-xylene at 130–140°C yields 3-benzoyl-4-hydroxy-6-phenyl-2H-pyran-2-one (VI) via phenyl ketene (V). The compound (VI) was converted into the corresponding 3-benzoyl-4-hydroxy-6-phenylpyridin-2(1H)-one (VII), and 3-benzoyl-2-oxo-6-phenyl-2H-pyran-4-yl acetate (VIII), by its reactions with ammonium hydroxyde, and acetic anhydride, respectively. On the other hand, a series of new various metal complexes (IX-XIa, XIb) of VI was synthesized. The results suggest that the compound VI as bidentate ligand indicate a binuclear structure for the Cu(II) complex with square-planar geometry. The Ni(II) and Zn(II) complexes are of tetrahedral and the Co(II) complex is also octahedral geometry with water molecules at the axial positions. The structures of compounds and complexes were characterized on the basis of elemental analysis, Mass, IR, ¹H, and ¹³C NMR spectra. The text was submitted by the authors in English.     

On Suborbital Graphs for the Modular Group

This paper proves a conjecture of G. A. Jones, D. Singermanand K. Wicks, that a suborbital graph for the modular groupis a forest if and only if it contains no triangles. 2000 MathematicsSubject Classification 05C05, 05C20, 20H35.     

Capsaicin emulsions: Formulation and characterization

Oleoresin capsicum, the oil extract of chili pepper, is mainly composed of capsaicin. Capsaicin is a hydrophobic volatile compound exhibiting antimicrobial activity against various microorganisms. Capsaicin in the form of an emulsion-based carrier system could be a good alternative to enhance bioavailability and simultaneously to increase the shelf-life of food. In this study, capsaicin emulsions were formulated using three different surfactants (Tween 80, commercial soy lecithin, and sucrose monopalmitate/SMP). Effects of aqueous phase composition, pH, and heating the pre-homogenized dispersion were investigated. For characterization, NMR relaxometry, color, turbidity, and antioxidant activity experiments were conducted. Antimicrobial efficacies of the emulsions were also evaluated against Escherichia coli andStaphylococcus aureus. Mean particle sizes of emulsions with surfactants Tween 80, lecithin, and SMP were found to be 68.30, 582.63, and 50.10?nm, respectively. Lecithin-containing emulsions showed the highest antimicrobial activity against S. aureus with 4.60?log reduction, whereas the same effect was observed in Tween 80-containing emulsions against E. coli with 3.86 log reduction. Emulsions prepared with SMP showed the highest antioxidant activity with 0.482?mg DPPH/L emulsion. The formulated emulsions have the potential to be used in food industry as antimicrobial food grade solutions.     

On the stability at all times of linearly extrapolated BDF2 timestepping for multiphysics incompressible flow problems

We prove long‐time stability of linearly extrapolated BDF2 (BDF2LE) timestepping methods, together with finite element spatial discretizations, for incompressible Navier‐Stokes equations (NSE) and related multiphysics problems. For the NSE, Boussinesq, and magnetohydrodynamics schemes, we prove unconditional long time L² stability, provided external forces (and sources) are uniformly bounded in time. We also provide numerical experiments to compare stability of BDF2LE to linearly extrapolated Crank‐Nicolson scheme for NSE, and find that BDF2LE has better stability properties, particularly for smaller viscosity values. © 2016 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 999–1017, 2017