Interaction of peristaltic flow with pulsatile magneto-fluid through a porous medium

Summary The interaction of purely periodic mean flow with a peristaltic induced flow is investigated within the framework of a two-dimensional analogue. The mathematical model considers a viscous incompressible fluid under the effect of a transverse magnetic field through a porous medium between infinite parallel walls on which a sinusoidal traveling wave is imposed. A perturbation solution to the complete set of Navier-Stokes equations is found for the case in which the frequency of the traveling wave and that of the imposed pressure gradient are equal. The ratio of the traveling wave amplitude to channel width is assumed to be small. For this case a first-order steady flow is found to exist, as contrasted to a second-order effect in the absence of the imposed periodic pressure gradient. The effect of the magnetic parameter, permeability parameter and the various parameters included in the problem are discussed numerically.     

Synthesis of 9-Hydroxy-1H-Benzo[f]chromene Derivatives with Effective Cytotoxic Activity on MCF7/ADR,P-Glycoprotein Inhibitors,Cell Cycle Arrest and Apoptosis Effects

β-Enaminonitriles bearing 9-hydroxy-1H-benzo[f]chromene moiety was synthesized. The targeted compounds were evaluated for their anti-proliferative activity against three human tumor cell lines, PC-3, SKOV-3 and HeLa, and the active cytotoxic compounds were further evaluated against cancer cells, MCF-7/ADR, and two normal cell lines, HFL-1 and WI-38. Few compounds were assigned to be the most potent derivatives against PC-3, SKOV-3 and HeLa cell lines in comparison with Vinblastine and Doxorubicin. Several compounds possessed a relatively good potency against MCF-7/ADR cells as compared with Doxorubicin and were tested as a P-gp inhibitor. Moreover, the halogenated substituents, 2,4-F₂, 2,3-Cl₂, 2,5-Cl₂ and 3,4-Cl_2; have good potency against P-gp-mediated MDR in MCF-7/ADR as compared with Doxorubicin. Meanwhile, Rho123 accumulation assays revealed that few compounds effectively inhibited P-pg and efflux function. In addition, certain derivatives induced apoptosis and an accumulation of the treated MCF-7/ADR cells in the G1, S and G1/S phases.     

Sorption performance of light rare earth elements using zirconium titanate and polyacrylonitrile zirconium titanate ion exchangers

Lanthanum, cerium, neodymium, and samarium were sorption from aqueous solutions using zirconium titanate (ZrTi) and polyacrylonitrile zirconium titanate (PANZrTi) ion exchangers. The characterizations of prepared materials were performed using XRD, SEM, FTIR, TGA, and DTA techniques. The sorption behavior of various ions toward synthesized resin has been studied depending on reaction temperatures, pH values, and initial concentrations. The selectivity order found is Sm³⁺?>?Nd³⁺?>?Ce³⁺?>?La³⁺ on ZrTi-100, Ce³⁺?>?Sm³⁺?≈?Nd³⁺?>?La³⁺ on ZrTi-150, and Sm³⁺?≈?Ce³⁺?>?Nd³⁺?>?La³⁺ on PANZrTi depending on the condition of prepared ZrTi samples. The K_d for lanthanide ions was slightly decreased with temperature increased, which indicated the exothermic nature. The sorption data obtained for equilibrium conditions have been analyzed using the different isotherm models, and the applicability of these isotherm equations was compared by the correlation coefficients, R². It was established that the equilibrium isotherm models’ applicability follows the order: Langmuir?>?Dubinin– Radushkevich?>?Freundlich. It is found the Ce³⁺ has high adsorption capacity on each of ZrTi-100 and ZrTi-150, while Nd³⁺ has high adsorption capacity on PANZrTi.     

AC conductivity and dielectric properties of GeSexTl0.3 amorphous thin films

AC conductivity and dielectric properties have been studied for amorphous thin films with different thicknesses of glassy system GeSe_xTl_0.3 with X = 3, 4 that prepared with thermal evaporation technique. The measurements are taken at temperature range (303-403 K) and frequency range (10²-10⁵ Hz).AC conductivity σ_ac(ω) is found to be proportional to ω^s where s < 1. The temperature dependence of the ac conductivity and the parameter s can be discussed with the aim of the correlated barrier-hopping (CBH) model.The dielectric constant ?′and the dielectric loss ?″ showed frequency and temperature dependence. The maximum barrier height W_M calculated from the dielectric measurements according to Giuntini equation are in good agreement with that proposed by the theory of hopping of charge carriers over a potential barrier as suggested by Elliott in the case of chalcogenide glasses.     

Analysis of saponins as bioactive zoochemicals from the marine functional food sea cucumber Bohadschia cousteaui

The edible portion of sea cucumber, body walls, is a source of natural bioactive compounds. Triterpene saponins are the main chemical constituents in sea cucumber that have potential interest for the body health and food industry. Twenty-one lanostane-type non-sulphated triterpene glycosides were isolated from the methanol/methylene chloride extract of the body walls of Bohadschia cousteaui. Ten new saponins called coustesides A (1), B (3), C (9), D (10), E (11), F (12), G (15), H (16), I (17) and J (18), including two pentasaccharide and eight hexasaccharide saponins, together with eleven known triterpene glycosides, were isolated by reversed-phase semi-preparative HPLC. Their structures were mainly determined by 1D- and 2D-NMR (¹H, ¹³C, COSY, TOCSY, HSQC, HMBC and ROESY) as well as MS experiments and acid hydrolysis. Most of the isolated compounds showed good antifungal activity against Candida albicans. Moreover, sea cucumber B. cousteaui is a rich source of biologically active saponins. Therefore, sea cucumbers are eaten for their therapeutic values as a functional food than for their seafood taste.     

Evaluation of the Effect of Polymeric Compounds as Compatibilizers for NR/EPDM Blend

The degree of compatibility of NR/EPDM blend can be improved by the use of specially selected polymeric compounds. Acrylonitrile and N-(4-chlorophenyl) acrylamide were homopolymerized and then copolymerized. The two homopolymers and the copolymer were incorporated each into the noncompatible blend system (50/50) NR/EPDM as compatibilizers. The effects of these compounds on the compatibility of both rubbers were evaluated by ultrasonic, differential scanning calorimetry (DSC), and rheometric techniques. The results obtained were compared with those of a reference blend. It was found that a fairly good compatibility had been achieved using polyacrylonitrile.     

One–bath dyeing of polyester/wool blend with disperse dyes

The present work aims to investigate and develop a one–bath dyeing process for most common blend fibres to replace the conventional two–step process usually applied to dye each fibre constituent separately. The main objectives of the proposed process is the conservation of energy, raw materials, dyes, auxiliaries and labour.     

Using difference spectrophotometry to study the influence of different ions and buffer systems on drug protein binding.

Difference spectrophotometry was used to investigate the effect of different ions and buffer systems on the binding of the anti-inflammatory drug tenoxicam to human serum albumin (HSA). Chloride anions, as well as sodium cations, were found to decrease the binding affinity. The effect of chloride ions was greater on the primary binding constant K1, while sodium ions had a greater effect on the secondary binding constant K2. The number of binding sites n1 and n2 were not affected except at 0.12% HSA, for which the presence of sodium ions halved n2. Potassium ions significantly increased K1. The presence of potassium instead of sodium ions increased binding affinity at lower HSA concentrations. The number of binding sites n1 and n2 were fewer in presence of potassium than in the presence of sodium ions except at 0.12% HSA. The divalent calcium and magnesium cations increased the binding affinity of HSA to tenoxicam, with a greater effect on K1. The effect of magnesium ions on K1 occurred when the MgCl2 concentration was increased to 3 and 9 mM, with the former seeming to be a critical concentration. The number of primary binding sites n1 was not affected by calcium ions, but was halved by 1 mM MgCl2. Both calcium and magnesium cations decreased n2, which was halved when the concentration of either cation was increased to 9 mM. The effect of buffer systems on tenoxicam binding to HSA was dependent on HSA concentration. The value of K1 was higher in Sorensen's phosphate buffer than in Tris [tris(hydroxymethyl) aminomethane HCl] buffer when the HSA concentration was 0.04% and 0.16%, while the reverse was observed at 0.08% and 0.12% HSA. The other binding parameters (K2, n1, and n2) were higher in Sorensen's phosphate than in Tris buffer. However; at certain HSA concentrations, the values of such parameters were comparable in both buffer systems.     

Treatment of TENORM waste: Phosphogypsum produced in fertilizer industry

This study concerns treatment of phosphogypsum (PG) waste from phosphoric acid production, containing ²²⁶Ra as major radioactive contaminant. Physical and chemical treatment was performed. The physical treatment was based on the particle size separation (dry and wet frationation), whereas the chemical treatment was carried out using leaching solutions (single and sequential leaching processes). The results showed that the particle size separation affected the distribution of radionuclides in PG waste. High enrichment fators (Q) of ²²⁶Ra and ²¹⁰Pb were obtained in the wet fractionation. The Q value for ²²⁶Ra and ²¹⁰Pb was 3.1 and 3.9 compared to the PG bulk. The chemical leaching conditions of PG waste were optimized. In the single chemical leaching, 40% of total radium-226 in PG was removed. In the sequential leaching, about 87% of ²²⁶Ra was removed when the PG waste was washed with alkali solutions and pretreated and leached with a nitric acid solution.