This paper characterized bovine extraocular muscles (EOMs) using creep, which represents long-term stretching induced by a constant force. After preliminary optimization of testing conditions, 20 fresh EOM samples were subjected to four different loading rates of 1.67, 3.33, 8.33, and 16.67%/s, after which creep was observed for 1,500 s. A published quasilinear viscoelastic (QLV) relaxation fun...

In the present study, we examine a worm-like micelle consisting of a nonionic surfactant system of polyoxyethylene phytosterol (PhyEO(m))/glycerin fatty acid monoester (GFA-C(n))/Water (m=10, 20, 30; n=8, 10, 12) using rheological measurements looking towards potential application of the system as a gel base. Phase diagrams in the dilute region of the PhyEO(m)/GFA-C(n)/Water systems show the fo...

In matrix acidizing operations, the main goal is increasing permeability. For production engineers, it is desirable that acid could be injected into whole [M.N.1] [amehri.gh2] pay zone. Sometimes, this pay zone has a long height and various sub-layers which have different permeability values. To prevent acid from going completely into the most permeable sub-layer, one of the useful techniques i...

Surfactants are characterized by the essential features that we saw in sodium oleate. A surfactant molecule has a hydrophilic (water-loving) head and a long hydrophobic (water-hating or oil-loving) tail. For this reason, we often describe surfactants is being amphiphilic molecules they love everything. Surfactants can be categorized according to the charge present in the hydrophilic portion of ...

Imidazolium-based ionic surfactants with hydrocarbon tails of different sizes were simulated with lipid bilayers at different salt concentrations. Starting with the random position of ionic surfactants outside the bilayer, surfactants with long tails mostly insert into the bilayer, while those with short tails show the insertion of fewer surfactant molecules, indicating the effect of the tail l...

Abstract Background Viscoelastic soluble polymeric additives have been used successfully for a long time as drag reducers in pipelines carrying commercial liquids like crude oil. Most of these polymers suffer from irreversible degradation when exposed to high shearing zones valves, elbows, and pumps which reduces, or eliminates, its flow enhancement effect. Insoluble were proven be an effective...

Nonionic surfactants are amphipathic molecules consisting of a hydrophobic (alkylated phenol derivatives, fatty acids, longchain linear alcohols, etc.) and a hydrophilic part (generally ethylene oxide chains of various length). Although not as important commercially, tertiary amine and various sugar surfactants are also nonionic surfactants. Due to their favorable physicochemical properties, no...

This paper presents a review on recent progress in quantitative structure-property relationship (QSPR) studies of surfactants and applications of various molecular descriptors. QSPR studies on critical micelle concentration (cmc) and surface tension (gamma) of surfactants are introduced. Studies on charge distribution in ionic surfactants by quantum chemical calculations and its effects on the ...

The “head” part of surfactant molecules consist of a polar or ionic group. The “tail” of many surfactants consist of a single hydrocarbon chain whereas that of some other surfactants, e.g., phospholipids, are made of two hydrocarbon chains both of which are connected to the same head. In contrast, gemini surfactants2–5, consist of two single-chain surfactants whose heads are connected by a “spa...