Determination of benzimidazoles in pharmaceuticals and human serum by high-performance liquid chromatography

A liquid chromatographic method is described for the quantification of prednisolone, benzimidazoles, and preservatives using a C₁₈ analytical column as stationary phase. The mobile phase was 30:70 methanol:pH 2.5 phosphate buffer at a flow rate of 1.0 mL min^?1 with absorbance detection at 235 nm. The method was linear for concentrations ranged from 40–10,000 ng mL^?1. Low values of coefficient of variance were obtained when samples were analyzed as replicates. Excellent recovery values were recorded in commercial products and fortified samples. International Conference of Harmonization protocols were employed to perform comprehensive method validation. The reported method has applications for pharmaceutical and serum samples.     

Calculation of Fluid Flow in the Oil Well under the Action of Powder Gas Generator

A numerical algorithm is developed, and the parameters of fluid flow in the oil well under the action of powder charge are calculated. For different combustion conditions, the dependence of gas pressure on the time and the maximum amplitude of fluid rise are found. The value is obtained for decreasing the pressure in the well relative to the hydrostatic pressure in the stratum; the hydrostatic pressure arises in cooling down the gases to the ambient temperature.     

Encapsulation of organic UV ray absorbents into layered double hydroxide for photochemical properties

Organic–inorganic nanohybrids, 3,4-dihydroxycinnamic acid/layered double hydroxide (CA/LDH), 4-hydroxy-3,5-dimethoxycinnamic acid/layered double hydroxide (SA/LDH), and 3-amino-5-triflouromethylbenzoic acid/layered double hydroxide (FBA/LDH) have been synthesized by co-precipitation reaction of organic ultraviolet (UV) ray absorbents such as 3,4-dihydroxycinnamic acid, 4-hydroxy-3,5-dimethoxycinnamic acid, 3-amino-5-triflouromethylbenzoic and Zn₂Al layered double hydroxide (LDH). Detailed structural and absorption properties of the nanohybrids were studied by using X-ray diffraction (XRD), FT-IR and UV-Vis transmittance spectra which revealed that organic UV absorbents have been intercalated into the interlayer spaces of LDH and all nanohybrids showed excellent UV ray absorption. All the nanohybrids showed a lower catalytic activity as compared to the net organic UV ray absorbents by applying air oxidation to castor oil.     

Simulation of thermal and velocity slip on the peristaltic flow of a Johnson–Segalman fluid in an inclined asymmetric channel

This research is concerned with the peristaltic motion of a Johnson–Segalman fluid in an inclined asymmetric channel. The equations for a magnetohydrodynamic fluid in an inclined asymmetric channel are developed. Both the thermal and velocity slip conditions are used. Series solutions for stream function, temperature, pressure gradient and heat transfer coefficients are derived. The solutions are compared with the previous published work. Numerical integration has been performed for pressure rise per wavelength. Graphical results are presented and discussed for some embedded parameters. A comparative study with the existing available results is shown.     

Flash-boiling atomization

Flash-boiling atomization is one of the most effective means of generating a fine and narrow-dispersed spray. Owing to its complexity its potential has not been fully realized to date. The paper reviews the present knowledge of the different mechanisms involved in the flash-boiling atomization process. These include intense nucleation, fast bubbles’ growth and liquid atomization. The inter-relationships between the distinctive processes determine the spray quality. Recent experimental observations and physical interpretations have improved our insight and led to better understanding of the whole process. One practical result is the establishment of design criteria for an optimal flash-boiling atomizing system.     

Another view of the upper and intermediate explosion limits of a H2–O2 system

In the present note we consider the two simultaneous mechanisms that are dominated by gas-phase reactions, namely the upper and intermediate explosion limits, and show that by employing the Le-Chatelier rule, a unified explosion limit is obtained in the form of a single analytical expression.     

Biomathematical study of non‐Newtonian nanofluid in a diverging tube

The present article deals with the peristaltic ?ow of a nano‐Eyring Prandtl ?uid model in a diverging tube. The governing equations for the considered model in view of the nanoparticles are presented in cylindrical coordinates using long wavelength and low Reynolds number approximation. The resulting nonlinear di?erential equations are solved for velocity, temperature, nanoparticle, and pressure gradient using the homotopy perturbation method. Numerical integration has been carried out for pressure rise, frictional forces, velocity, temperature, and nanoparticles. The numerical results are discussed through graphs. The e?ects of various emerging parameters are investigated for ?ve di?erent peristaltic waves. Streamlines have been plotted at the end of the article for the considered waveforms. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21047     

Bioscouring of cellulosic textiles

A study on bioscouring of cotton yarn with the pectinase enzyme was carried out and the results compared with the usual alkali scoured material. The results indicate that the bioscoured yarn has lower percentage of non‐cellulosic constituents (impurities), higher tenacity, higher absorbency and the same whiteness after hydrogen peroxide bleaching as compared with the Solomatic bleached yarn. A similar study on cotton fabric indicates that a combined desizing and bioscouring is not feasible at least at ambient temperature. More work, however, is required to compare bioscouring followed by bleaching with the Solomatic or two step scouring and bleaching methods. One interesting finding is that the efficiency of washing of the desized fabric improves on adding ethylene diamine tetraacetic acid sequestrating agent in the wash liquor. Additional advantages of bioscouring are lower energy cost and more easily biodegradable effluent in comparison to alkali scouring.     

Thermal and velocity slip effects on the peristaltic flow of a six constant Jeffrey’s fluid model

In the present article, peristaltic flow of an incompressible six constant Jeffrey’s fluid model have been discussed. The flow have been analyzed in a wave frame of reference moving with the wave speed c. We have modeled the governing equations of a two dimensional and two directional flow under long wave length and low Reynold’s number approximation. Slip effects have been utilized for both velocity and temperature profile. The analytical solution for the proposed problem have been evaluated. The expression for the pressure rise is calculated using numerical integration. The graphical results are presented to interpret various physical parameters of interest for velocity, pressure gradient and temperature profile.     

Physics-informed deep learning study for MHD particle-fluid suspension flow with heat transfer in porous annular-sector duct

Thermal enhancement remains a critical requirement in different engineering applications. Many factors can affect the efficiency of the techniques used for this aim. The purpose of this study is to investigate the impact of particle-fluid suspensions with heat transfer through porous annular-sector duct on enhancement techniques and address the potential application of deep learning to suspension problems. The analysis is focused on the fully developed region of the forced convection flow. Thermal and rheological properties of particle-fluid suspensions were studied using physics-informed neural networks exploiting transfer learning capabilities for making parameter analysis. Another finite element solution was introduced as a measure of accuracy and to support our findings. Results were prepared in a comparative manner for both solvers including contour plots, tabular, and two dimensional figures. The average Nusselt number and friction factors were calculated for different cases to investigate the value of the thermal performance factor. Our results indicate the downside of suspensions on thermal enhancement and their negative impact on other techniques.