On rotationally starlike logharmonic mappings

This paper considers the class of all mappings of the form where h and g are analytic in the unit disk U, normalized by , and such that is logharmonic with respect to an analytic self‐map a of U. A distortion estimate and the radius of starlikeness are obtained for this class. Additionally, a solution to the problem of minimizing the moments of order p over the class is found, as well as an estimate for arclength.     

Quaternary (liquid + liquid) equilibrium data for the extraction of toluene from alkanes using the ionic liquid [EMim][MSO4]

(Liquid + liquid) equilibrium (LLE) studies for the extraction of aromatics from alkanes present in the petroleum fractions are important to develop theoretical/semiempirical (liquid + liquid) equilibrium models, which are used in the design of extraction processes. In this work, the ionic liquid 1-ethyl-3-methylimidazolium methylsulfate, [EMim][MSO₄], was evaluated as potential solvent for the separation of toluene from heptane and cyclohexane. The LLE data for the quaternary system {heptane (1) + cyclohexane (2) + toluene (3) + [EMim][MSO₄] (4)} were experimentally determined at T = 298.15 K and atmospheric pressure. Moreover, the LLE data for the ternary systems {heptane or cyclohexane (1) + toluene (2) + [EMim][MSO₄] (3)} were also determined. Solute distribution ratios and selectivities were calculated and analysed in order to evaluate the capability of the ionic liquid to accomplish the separation target. A comparison between the solute distribution ratios and selectivities for the quaternary and the ternary systems was also made. Finally, the experimental tie-line data were correlated with the NRTL model.     

Preparation and characterization of La<Subscript>0.6</Subscript>Sr<Subscript>0.4</Subscript>Co<Subscript>0.2</Subscript>Fe<Subscript>0.8</Subscript>O<Subscript>3-δ</Subscript> thin-film membrane on porous support by dip-coating method

Perovskite-type La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF6428) thin-film membrane prepared by modified Pechini sol–gel process, was successfully deposited on porous support of similar composition using dip-coating method. Fine grain and crack-free film with perovskite structure was obtained at sintering temperature of 800 °C and dwelling time of 60 min. The cross-sectional image indicated that LSCF6428 thin-film membrane coated on the porous support showed excellent adhesion to the support with uniform thickness. The minimum dense layer thickness obtained by dip-coating method was around 0.5 μm. It was found that the oxygen permeability of the supported thin film was lower than that of the perovskite support, which indicated that the pores of the support were reduced by thin-film deposition on the support surface. The reduction in the pore size led to the more selective permeation mechanism contributes to the overall permeation. Successful deposition of LSCF6428 thin-film membrane on porous support can be considered as a promising technique for the preparation of oxygen separation membrane.     

The hydrolytic effect of moisture and hygrothermal aging on poly(butylene succinate)/organo-montmorillonite nanocomposites

The study of hydrolysis on biodegradable poly(butylene succinate) (PBS) is essential to predict the materials properties in a humid environment. In this study, PBS nanocomposites were exposed to different conditions of relative humidity (RH) and temperature. The moisture uptake increased with organo-montmorillonite (OMMT) loading and the RH of the testing environment. The exposure of PBS and the nanocomposites to a humid environment caused changes in the mechanical properties. The hydrolytic degradation becomes more pronounced upon hygrothermal aging at high temperature, whereby premature failure occurred. PBS nanocomposites were found to exhibit a better hydrolytic stability than neat PBS. The degradation was evaluated through Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC). A drastic reduction in the molecular weight of PBS has revealed the occurrence of degradation after exposure to moisture and heat. This has led to an alteration of the thermal behavior as investigated using differential scanning calorimetry (DSC).     

Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district,Tamil Nadu,India

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv.     

Closure properties of operators on the Ma-Minda type starlike and convex functions

A normalized univalent function f is called Ma-Minda starlike or convex if zf^′(z)/f(z)?φ(z) or 1+zf^″(z)/f^′(z)?φ(z) where φ is a convex univalent function with φ(0)=1. The class of Ma-Minda convex functions is shown to be closed under certain operators that are generalizations of previously studied operators. Analogous inclusion results are also obtained for subclasses of starlike and close-to-convex functions. Connections with various earlier works are made.     

Developing a validated liquid chromatography-mass spectrometric method for the simultaneous analysis of five bioactive quassinoid markers for the standardization of manufactured batches of Eurycoma longifolia Jack extract as antimalarial medicaments

An extensive comparative study on the electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) mass spectrometry using automated flow injection analysis (FIA), was performed on eurycomanone (1), 13α(21)-epoxyeurycomanone (2), eurycomanol (3), eurycomanol-2-O-β-d-glucopyranoside (4), and 13,21-dihydroeurycomanone (5), the bioactive markers isolated from Eurycoma longifolia. The effects of eluent mixture (methanol or acetonitrile in water) and acidic modifiers (acetic acid, formic acid and trifluoroacetic acid) on the ionization efficiency of the markers were also investigated. The ESI in the positive ion mode with methanol containing 0.1% (v/v) acetic acid was selected for the subsequent optimization of nebulizer pressure, dry gas flow, dry gas temperature and capillary voltage to improve the sensitivity of the total ion chromatogram (TIC). Fragmentation of the analytes was further investigated by varying the capillary exit offset voltage and fragmentation amplitude in positive mode of ESI. The detection limits (LODs) were determined in isolation mode (selected ion monitoring, SIM). Their limits of detection (LODs) ranged between 0.03 and 0.1μgmL(-1) while the intra-day and inter-day precisions were less than 5.72% and 4.82%, respectively. The method was next applied for the simultaneous analysis of the markers to standardize various batches of manufactured extracts of E. longifolia for potential use as antimalarial products. Multiple Reaction Monitoring (MRM) mode was used for the quantification of analytes which gave protonated molecular ion, [M+H](+). For those without pseudo-molecular ions, SIM mode was used to quantify the analytes. The batches contained 5.65-9.95% of eurycomanone (1), 5.21-19.75% of eurycomanol (3) and 7.59-19.95% of eurycomanol-2-O-β-d-glucopyranoside (4) as major quassinoids whereas, 13α(21)-epoxyeurycomanone (2), and 13,21-dihydroeurycomanone (5) were much lower in concentrations of 0.78-3.90% and 0.47-1.76%, respectively.     

Enhancement of the photocatalytic activity of TiO(2) by doping it with calcium ions

Titanium dioxide (TiO(2)) with an enhanced photocatalytic activity was developed by doping it with calcium ions through a sol-gel method. The developed photocatalysts were characterized by Fourier transform infrared (FTIR) spectroscopy, N(2) physisorption, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction. Their surface morphologies were studied using surface scanning electron microscopy (SEM). The XPS analyses confirmed the presence of Ti, O, Ca, and C in the Ca-doped TiO(2) sample. The activities of the catalysts were evaluated by photocatalytic degradation of an azo dye, acid red 1 (AR1), using UV light irradiation. The results of the investigations revealed that the samples calcined at 300 °C for 3.6h in a cyclic (2 cycles) mode had the best performance. Lower percentage dopant, 0.3-1.0 wt.%, enhanced the photocatalytic activity of TiO(2), with the best at 0.5 wt.% Ca-TiO(2). The performance of 0.5 wt.% Ca-TiO(2) in the degradation of AR1 was far superior to that of a commercial anatase TiO(2) Sigma product CAS No. 1317-70-0. The effect of pH on the degradation of AR1 was studied, and the pH of the dye solution exerted a great influence on the degradation of the dye.     

Study and fabrication of europium picrate triethylene glycol complex

A mononuclear of [Eu(NO3)(Pic)(H2O)2(EO3)](Pic)·(0.73)H2O complex, where EO3=trietraethylene glycol and Pic=picrate anion, shows a red emission when used as an active layer in a single layer of ITO/EO3-Eu-Pic/Al configuration. The crystal structure of the complex consists of [Eu(NO3)(Pic)(H2O)2(EO3)]+ cation and [Pic]- anion. The Eu(III) ion is coordinated to the 10 oxygen atoms from one EO3 ligand, one Pic anion, one nitrate anion, and two water molecules. The complex is crystallized in triclinic with space group P-1. The hybrids in thin films I and II were prepared in the respective order solution concentrations of 15 and 20 mg/mL the emissive center. Comparing the photoluminescence (PL) and electroluminescence (EL) spectra, we can find that all emissions come from the characteristic transitions of the Eu(III) ion. The EL spectra of both thin films showed the occurrence of the most intense red-light emission around at 612 nm. Comparison of organic light-emitting device (OLED) current intensity characteristics as a function of voltage (I-V) show that the thin film I is better than those found for the thin film II. The thickness of the emitting layer is an important factor to control the current-voltage curve. The sharp and intense emission of the complex at low voltage indicates that the complex is a suitable and promising candidate for red-emitting materials.     

Numerical studies on a novel split-step quadratic B-spline finite element method for the coupled Schrödinger–KdV equations

We propose a novel split-step quadratic B-spline finite element method for solving the initial-boundary value problem of the coupled Schrödinger–KdV equations. A full-discrete finite element scheme is constructed. The conserved properties of the full-discrete scheme are proved. Detailed numerical results show the efficiency of our scheme.