Seasonal fluctuations of esterase-6 allelic frequencies of Drosophila melanogaster in an area heavily sprayed with insecticides.

uploaded by Plazi from Taxodro

Oleic acid-based compounds as lube oil additives for engine oil

The ongoing research focuses on preparing three compounds, based on oleic acid esters, through two steps to form 2-(3-acetylthioureido)-3-hydroxy-2-(hydroxymethyl) propyl oleate (Compound A), 2-(3-acetyl thioureido)-2-(hydroxymethyl) propane-1,3-diyl dioleate (Compound B) and 2-(3-acetyl thioureido)-2-[(oleoyloxy) methyl] propane-1,3-diyl dioleate (Compound C). The chemical structure of the prepared compounds has been distinguished and ascertained using different spectroscopic techniques as Fourier transform infrared spectroscopy (FTIR), proton and carbon nuclear magnetic resonance (1H and 13C NMR), quantum chemical study “theoretical studies”. The efficacy of the prepared compounds was ultimately scrutinized as lubricating oils’ additives. It gives excellent results as detergent/ dispersant additives. Both the experimental and theoretical quantum chemistry studies of antioxidant compounds yield insufficiently effective findings. The strength of the produced compounds shows that the one with three oleic groups is most effective when compared to one and two groups. Additionally, the dispersancy increases as the percentage of the dispersants rises from 0.25 to 1.5 %. Keep in mind that as time passes, dispersancy increases more. C > B > A, correspondingly, is the order in which the dispersancy percent decreases

Electrophysical characteristics of polyurethane/organo-bentonite nanocomposites

Modification of the Egyptian Bentonite (EB) was carried out using organo-modifier namely; octadecylamine ODA. Before the modification, the cation exchange capacity (CEC) of the EB was measured, also it was purified from different impurities using HCl and distilled water. The Organo-bentonite OB was characterized using IR, XRD, and TEM. PU/ODA-B nanocomposites were prepared by in situ polymerization then characterized by XRD and TEM. An amount of ODA-B ranging from 0.25% up to 5% by weight was added to the polyol component of the resin before mixing with toluene diisocynate TDI. TEM showed that the nanocomposites achieved good dispersion in the polyurethane matrix. The mechanical, swelling and electrical properties of the nanocomposites were measured. The results indicate that the tensile strength of all the nanocomposites enhanced with the addition of OB compared with the pure PU. The crosslink density of the nanocomposites increases with increasing the content of OB. The Pool–Frenckel conduction mechanism predominates for all the nanocomposite samples and the blank one

Evaluation of some vanillin-modified polyoxyethylene surfactants as additives for water based mud

Water-based drilling fluids are increasingly being used for oil and gas exploration and are generally considered to be more environmentally acceptable than oil-based or synthetic-based fluids. In this study, new types of vanillin-modified polyoxyethylene surfactants were evaluated as additives in water-based mud. Their rheological properties in water-based mud were investigated which included the apparent viscosity, the plastic viscosity, the yield point, the gel strength, the thixotropy as well as the filtration properties. Also, the effect of high temperature on the rheology of the formulated water based mud was studied. The tested ethoxylated non-ionic surfactants showed good results when utilized in the formulation of water-based mud

Three novel Gemini amide amphiphilics synthesis, characterization, thermodynamics, surface properties and biological activity

Three Gemini amphiphiles had prepared through reaction of amide of succinic acid with different bromo olefins. Their chemical structure was emphasized different spectroscopic methods. the surface tension measurements were investigated at 20, 40 and 60 °C. The Gemini surfactant with the longest tail clarified enhancement of surface parameters values with elevating mixture temperature.Both (ΔGoads) & (ΔGomic) data are negative, providing spontaneously occurrence of adsorption and micellization processes while the positivity of (ΔSoads) &(ΔSomic) revealing more order for both processes. Thermodynamic behaviour increases by raising chain length. All of fabricated amphiphiles exhibited antimicrobial activity against bacteria and fungi

Physico-chemical characteristics of nano-organo bentonite prepared using different organo-modifiers

Different types of nano-organo bentonite (NOB) were prepared from the Egyptian Bentonite (EB). EB was characterized by energy dispersive X-ray EDX. It was purified from different impurities using a conventional method via the treatment with HCl and distilled water. The modification of the clay was carried out using different types of organo-modifiers namely; hexadecyl trimethyl ammonium bromide (HTAB), 3-aminopropyltriethoxysilane (Silane), octadecylamine (ODA), and dodecylamine (DDA). The cation exchange capacity (CEC) was measured for pristine bentonite after and before modification. The NB was characterized by FTIR, XRD, TEM, and TGA techniques. The obtained results indicated that variation of the interlayer space gallery was effected by the type of the penetrator used

Profiling the chemical content of <i>Ficus lyrata</i> extracts <i>via</i> UPLC-PDA-qTOF-MS and chemometrics

<div><p>This study attempts to elucidate the secondary metabolite profiles of <i>Ficus lyrata</i> leaves and fruits grown in Egypt. Non-targeted metabolite profiling <i>via</i> ultra performance liquid chromatography (UPLC)-qTOF-MS was used to identify various chemical classes in <i>F. lyrata</i> fruits and leaves (i.e. flavonoids, phenolic acids and fatty acids) analysed by chemometrics. A total of 72 metabolites were evaluated <i>via</i> a UPLC-qTOF-MS-based metabolomic study. Seventeen flavonoids were characterised and tentatively identified with the main constituents being catechins/procyanidins, <i>O</i>- and <i>C</i>-linked flavonoid glycosides. The major procyanidins were dimers and trimers comprising (epi)catechin and (epi)afzelechin units, whereas the predominant flavones were <i>C</i>-glycosides of luteolin and apigenin. Aside from these major flavonoid classes, a group of benzoic acids, caffeoylquinic acids, fatty acid and sphingolipids were also annotated. This study provides the most complete map for polyphenol distribution in <i>F. lyrata</i> leaves and fruits and the basis for future investigation of its fruits nutritional value or possible nutraceutical uses.</p></div