Charged spherically symmetric solution in Mikhail-Wanas field theory

A set of coupled differential equations obtained by Wanas in the Mikhail-Wanas generalized field theory is completely integrated.     

Mössbauer studies of polyethyl methacrylate containing ferric chloride as a stabilizer

A convenient technique is described for removal of sodium and other metal ion interference from sodium iodide-123 and sodium iodide-124 solutions used to label antibodies. Distillation methods have disadvantages compared to column purification techniques used to remove salt impurities that interfere in radioiodination reactions.This research was supported in part by Research Grant /85-0025/ from Sheik Abdulrahman Ali Al-Jeraisy.     

Green solid-phase peptide synthesis 4. γ-Valerolactone and N-formylmorpholine as green solvents for solid phase peptide synthesis

Herein, we report the use of γ-valerolactone (GVL) and N-formylmorpholine (NFM) as DMF substitutes in polystyrene based SPPS. The solubility of selected amino acids and coupling reagents were studied in GVL and NFM, followed by their use in the successful synthesis of Aib-enkephalin pentapeptide (H-Tyr-Aib-Aib-Phe-Leu-NH₂) and Aib-ACP decapeptide (H-Val-Gln-Aib-Aib-Ile-Asp-Tyr-Ile-Asn-Gly-NH₂).     

Time Resolved Microwave Interferometry Measurement of the Electron Density in a Pulsed 1,3-Butadiene Discharge

Pulsed plasmas containing organic precursors are becoming increasingly common for multiple applications. To understand the nature of such discharges, in-situ time resolved microwave interferometry measurements of the electron density in a 60 W pulsed inductively coupled 1,3-butadiene discharge have been made. Measurements were also made for continuous wave plasmas at 40, 50, 60 and 70 W power for comparison. The data shows that the time averaged electron densities are independent of pulse width at a particular duty cycle. In addition, time averaged values increase approximately linearly with increasing duty cycle. Such linearity in average density is tied to the ambipolar loss rate. This knowledge is important for understanding the growth kinetics of plasma polymerized films.     

Chlorella minutissima—A Promising Fuel Alga for Cultivation in Municipal Wastewaters

It is imperative to slash the cost of algal oil to less than $50 bbl^?1 for successful algal biofuel production. Use of municipal wastewater for algal cultivation could obviate the need for freshwater and the nutrients—N and P. It would also add CO₂ through bacterial activity. Chlorella minutissima Fott et Nova dominated the entire phycoflora year around and through each stage of the wastewater treatment at the oxidation pond system of Wazirabad (Delhi) in India. The ability to grow so profusely in such varied and contrasting situations made this alga unique. Besides pollution tolerance, it grew heterotrophically in dark under acidic conditions and as a mixotroph in presence of light over a range of organic C substrates. It could utilize both ammoniacal and nitrate nitrogen, survived anaerobicity, 5% NaCl and ?10 bar of osmotic stress. C. minutissima grew at pH 4–11 and raised the pH set initially by 1 to 3 units in 7.5 h. It showed gigantism and largely kept afloat in presence of utilizable organic carbon, while flocculated in mineral medium and on aging. The alga also possessed potential for biofuel production. The studied parameters indicate why C. minutissima was a potential biomass builder in municipal sewage and could be used to determine which other alga(e) may serve the purpose.     

Thermoluminescence characteristics of inorganically and organically capped ZnS:Cu nanophosphors

ZnS:Cu nanophosphors were prepared by wet chemical methods and characterized by X-ray diffraction (XRD). The typical morphologies of the nanophosphors were investigated by scanning electron microscopy (SEM). The thermoluminescence (TL) properties of inorganically and organically passivated ZnS:Cu nanophosphors were investigated after γ-irradiation using a ⁶⁰Co source at room temperature. The TL glow curve of capped ZnS:Cu showed variation in TL peak and intensity as the capping agent was changed. Amongst the synthesized samples the TL glow curve of SiO₂ capped ZnS:Cu showed the highest TL intensity. It has been found that TL response of SiO₂ capped ZnS:Cu is linear in the range 10-550 Gy. A discussion of the obtained results is also presented.     

Ultrasonic degradation of polymers: effect of operating parameters and intensification using additives for carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA)

Use of ultrasound can yield polymer degradation as reflected by a significant reduction in the intrinsic viscosity or the molecular weight. The ultrasonic degradation of two water soluble polymers viz. carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) has been studied in the present work. The effect of different operating parameters such as time of irradiation, immersion depth of horn and solution concentration has been investigated initially using laboratory scale operation followed by intensification studies using different additives such as air, sodium chloride and surfactant. Effect of scale of operation has been investigated with experiments in the available different capacity reactors with an objective of recommending a suitable type of configuration for large scale operation. The experimental results show that the viscosity of polymer solution decreased with an increase in the ultrasonic irradiation time and approached a limiting value. Use of additives such as air, sodium chloride and surfactant helps in increasing the extent of viscosity reduction. At higher frequency operation the viscosity reduction has been found to be negligible possibly attributed to less contribution of the physical effects. The viscosity reduction in the case of ultrasonic horn has been observed to be more as compared to other large capacity reactors. Kinetic analysis of the polymer degradation process has also been performed. The present work has enabled us to understand the role of the different operating parameters in deciding the extent of viscosity reduction in polymer systems and also the controlling effects of low frequency high power ultrasound with experiments on different scales of operation.     

Absence of morphotropic phase boundary effects in BiFeO<Subscript>3</Subscript>–PbTiO<Subscript>3</Subscript> thin films grown via a chemical multilayer deposition method

We report an unusual behavior observed in (BiFeO₃)_1−x –(PbTiO₃) _x (BF–xPT) thin films prepared using a multilayer chemical solution deposition method. Films of different compositions were grown by depositing several bilayers of BF and PT precursors of varying BF and PT layer thicknesses followed by heat treatment in air. X-ray diffraction showed that samples of all compositions show mixing of two compounds resulting in a single-phase mixture, also confirmed by transmission electron microscopy. In contrast to bulk compositions, samples show a monoclinic (M_A-type) structure suggesting disappearance of the morphotropic phase boundary (MPB) at x=0.30 as observed in the bulk. This is accompanied by the lack of any enhancement of the remanent polarization at the MPB, as shown by the ferroelectric measurements. Magnetic measurements showed an increase in the magnetization of the samples with increasing BF content. Significant magnetization in the samples indicates melting of spin spirals in the BF–xPT films, arising from a random distribution of iron atoms. Absence of Fe²⁺ ions was corroborated by X-ray photoelectron spectroscopy measurements. The results illustrate that thin film processing methodology significantly changes the structural evolution, in contrast to predictions from the equilibrium phase diagram, besides modifying the functional characteristics of the BP-xPT system dramatically.     

Second order symmetric duality in nondifferentiable multiobjective fractional programming with cone convex functions

In the present paper, we consider Mond-Weir type nondifferentiable second order fractional symmetric dual programs over arbitrary cones and derive duality results under second order K?F-convexity/K?F-pseudoconvexity assumptions. Our results generalize several known results in the literature.     

Velocity correlations in dense granular flows observed with internal imaging

We show that the velocity correlations in uniform dense granular flows inside a silo are similar to the hydrodynamic response of an elastic hard-sphere liquid. The measurements are made using a fluorescent refractive-index-matched interstitial fluid in a regime where the flow is dominated by grains in enduring contact and fluctuations scale with the distance traveled, independent of flow rate. The velocity autocorrelation function of the grains in the bulk shows a negative correlation at short time and slow oscillatory decay to zero similar to simple liquids. Weak spatial velocity correlations are observed over several grain diameters. The mean square displacements show an inflection point indicative of caging dynamics. The observed correlations are qualitatively different at the boundaries.