the effect of temperature on the viscoelastic behavior of chicken meat frankfurters was assessed by creep recovery tests. compression creep-recovery tests were performed at room temperature (20°c) and refrigeration (5°c) on samples of cylindrical shape. the viscoelastic behavior of samples was characterized based on the parameters of the four-element burgers model. during the compression phase,...

The analysis of viscoelastic materials is one of the most important subjects in engineering structures. Several works have been so far made for the integral equation methods to viscoelastic problems. From the basic assumptions of viscoelastic constitutive equations and weighted residual techniques, a simple but effective Boundary Element (BE) formulation is developed for the Kelvin viscoelastic...

The rheological properties of four different Kuwaiti crude oils in the presence of polyacrylamide (PAA) were investigated. PAA was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. Four different temperatures (25, 30, 35, and 40 °C) were used to evaluate different viscoelastic parameters of the treated and untreated Kuw...

The effects of the surfactants, alcohol ethoxylate, amine ethoxylate, amine oxide and SDS on cell membranes were investigated using the lipid soluble spin label 5-doxyl stearic acid (5-DS). Electron paramagnetic resonance (EPR) spectroscopy revealed that the action of the surfactants was to significantly increase membrane fluidity of Proteus mirabilis, Staphylococcus aureus and Saccharomyces ce...

Surfactants have the special ability to interact with the lipid bilayer of cell membranes. The red blood cell is one of the most used cellular membrane models to study the mechanisms underlying surfactant – induced osmotic cell resistance.The aim of this study is the evaluation of the effect of the prepared surfactants on red blood cells (RBC) as a model for biological membranes. Also, in this ...

The biodegradation of polycyclic aromatic hydrocarbons (PAH) often is limited by low water solubility and dissolution rate. Nonionic surfactants and sodium dodecyl sulfate increased the concentration of PAH in the water phase because of solubilization. The degradation of PAH was inhibited by sodium dodecyl sulfate because this surfactant was preferred as a growth substrate. Growth of mixed cult...

Capsular polysaccharides (SPS) are the integral components of gram-negative bacteria, and also have potential uses as vaccines. In this paper, interaction of anionic SPS, isolated from Klebsiella K28, K43, K51 and K20, with cationic surfactants and cationicnonionic mixed surfactants were investigated by turbidimetric titration, viscometric method. Variation of size and zeta-potential was measur...

In this paper, we report studies which aim to elucidate the mechanisms involved in the antimicrobial activity of three cationic lysine-based surfactants: LLM, LALM, and C6 (LL)2. To this end, a simple membrane model (i.e., 1,2-dipalmitoyl-sn-phosphatidylcholine, DPPC) was used to explore the monolayer properties at the air/liquid interface. Compression π-A isotherms of mixtures of DPPC/lysine s...

Within the framework of a comprehensive investigation concerning the use of surfactants to enhance the in-situ remediation of Polycyclic Aromatic Hydrocarbons (PAH) contaminations in the subsurface, SMART (Streamtube Model for Advective and Reactive Transport), a multicomponent transport model, was developed to study the processes (interactions) taking place when surfactants and PAH migrate thr...