جستجوی مقالات مرتبط با کلیدواژه "ethylene glycol" در نشریات گروه "مواد و متالورژی"

Nanofluid is a suspension obtained by adding nanoscale particles (100 nm) to a base fluid to improve heat transfer. In this study, the effect of temperature and concentration of nanoparticles consisting of Alumina nanoparticles and Graphene nanosheets on the thermal conductivity of a base fluid consisting of water and ethylene glycol was studied. Also, 0.2% by volume of oleic acid (OA) and 0.2% by weight of sodium dodecyl sulfonate (SDS) were added to the base fluid as a surfactant to stabilize and disperse the nanoparticles. The volume fraction of nanoparticles of 0.05, 0.1, 0.5, 1, 1.5, 2 and 2.5% by volume and the tested temperatures were selected in the temperature range of 260-305 K. The morphology and microstructure of the nanoparticles were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermal conductivity of hybrid nanofluids was measured and compared with the base fluid. Results showed that thermal conductivity of water-ethylene glycol / nano Graphene-nano Alumina hybrid nanofluid depends on nanoparticle concentration and temperature. The thermal conductivity measurements of water-ethylene glycol / nano Graphene-nano Alumina hybrid nanofluid were compared with the thermal conductivity prediction models of nanofluids but there was no acceptable agreement. The results showed that increasing the temperature and volumetric concentration of nanoparticles increases the thermal conductivity of hybrid nanofluids. The maximum increase in thermal conductivity of hybrid nanofluid was 44.02% which was obtained in solid volume fraction of 2.5% and at temperature of 303 K.

The corrosion and corrosion inhibition of CK10 carbon steel in CO2-saturated 3% NaCl solution by anise extract (AE) dissolved in ethylene glycol (EG) was studied using polarization curves، electrochemical impedance spectroscopy (EIS) and surface analysis (AFM) methods. Inhibition efficiency increased with increase in AE concentration and temperature. The data suggest that AE functioned as inhibitor via a mixed-inhibitor mechanism and the inhibition process is attributed to the formation of a chemically adsorbed film of AE and EG on the surface of the metal via its polycentric adsorption sites. Thermodynamic adsorption parameters of studied inhibitor were calculated using the Langmuir adsorption Isotherm. Morphological studies of the carbon steel electrode surface were undertaken by atomic force microscopy (AFM).