Prediction of Aqueous Solution Surface Tension of Some Surfactant Mixtures and Composition of Their Monolayers at the Solution–Air Interface

Measurements of the surface tension of the aqueous solution of SDDS mixture with fluorocarbon surfactants (FC) were carried out and considered in light of the surface tension of aqueous solutions of individual surfactants. Similar analyses were made for many other aqueous solutions of binary and ternary mixtures, taking into account the literature data of the surface tension of aqueous solutions of TX100, TX114, TX165, SDDS, SDS, CTAB, CPyB and FC. The possibility of predicting the surface tension of the aqueous solution of many surfactant mixtures from that of the mixture components using both the Szyszkowski, Fainerman and Miller and Joos concepts was analyzed. The surface tension of the aqueous solutions of surfactant mixtures was also considered based on the particular mixture component contribution to the water surface tension reduction. As a result, the composition of the mixed surface layer at the solution–air interface was discussed and compared to that which was determined using the Hua and Rosen concept. As follows from considerations, the surface tension of the aqueous solution of binary and ternary surfactant mixtures can be described and/or predicted.

Efficiency of Extremophilic Microbial Mats for Removing of Pb(II), Cu(II) and Ni(II) ions from Aqueous Solutions

Two different extremophilic films were used as natural biosorbents to remove Cu(II), Ni(II) and Pb(II) from aqueous solution. Surface area, scanning electron microscope imaging and Fourier transformation infrared were used to characterize the surface of biosorbents. The results indicated high affinity of biosorbents to remove Pb(II) Cu(II) and Ni(II) with adsorption ratio ranged between 73.6–100% for both two biosorbent. The two biosorbents success to remove the metal ions from the aqueous mixture in the order of Pb(II) > Cu(II) > Ni(II). The maximum removal ratios of metal ions were achieved at pH = 6, 150 min contact time, 2.5 g/L biosorbent dose and 50 mg/L metal ions. The isothermal studies showed that both Langmuir and Freundlich models well expressed the adsorption process. Kinetically, the pseudo-second order reaction well express the type of reaction than pseud-first order reaction.

Development of a Gradient Descent Algorithm for Pathway Routing Based on Functional-Voxel Modeling

This paper considers a pathfinding algorithm using the gradient method for functional-voxel modeling problems. The basic principles of constructing gradient lines based on the functional voxel model are investigated. The tool to describe the scene with obstacles is the mathematical apparatus of R-functions. To solve the problem of pathfinding in a weakly deterministic environment, we propose an algorithm that is based on the use of: gradient method analyzing the color palette of images of local features of the function; mathematical apparatus of R- functions describing the topography of the solution surface at the current moment in time. An algorithm of target control that solves the problem of getting out of possible "trapped objects" is considered. For this, the principle of changing the position of the target was developed to control the gradient direction.

Adlay seed hull polysaccharide as a green corrosion inhibitor for mild steel in acid solution: Surface analyses and theoretical calculations

Adlay seed hull polysaccharide (ASP) was developed here as a green corrosion inhibitor for mild steel in 1 M HCl solution, and its inhibition effect was studied with electrochemical experiments,...