Graphene nanosheets have been synthesized from commercial expandable graphite by heating in a microwave oven and dispersing in ethanol by ultrasonication. Scanning and transmission electron microscopy and electron energy-loss spectroscopy and atomic force microscope showed that the nanosheets were about 2 nm in thickness and 10 microm in diameter. The field emission of the graphene sheets has b...

An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been reported in many wells, presents a big challenge in Maroon field. The main challenges are preventing gas migration and achieving zonal isolation using a competent cement sealant system which is able to withstand downhole stresses and high temperatures during production cycles. Unlike conventional cem...

an oil and gas well cementing in gachsaran formation, where sustained annular pressure has been reported in many wells, presents a big challenge in maroon field. the main challenges are preventing gas migration and achieving zonal isolation using a competent cement sealant system which is able to withstand downhole stresses and high temperatures during production cycles. unlike conventional cem...

suspension polymerization processes are significantly important in polymer bead formation. one of the important factors for bead size control in these processes is variation in surface tension. in this research, the prediction of optimum concentration of a surface active agent was investigated on the basis of the experimental surface tension diagrams. the experimental data show that the desired...

to explore the possibility of using graphene based biosensor, adsorption of hydrogen peroxide on graphene has been investigated using density functional theory. the electronic properties of defect free and defective graphene in the presence of different number of hydrogen peroxide have been studied. the graphene with the most stable configuration defect named as sw defect is considered. the hig...

IMPORTANCE Transcatheter aortic valve replacement (TAVR) is an effective treatment option for high-risk patients with severe aortic stenosis. Different from surgery, transcatheter deployment of valves requires either a balloon-expandable or self-expandable system. A randomized comparison of these 2 systems has not been performed. OBJECTIVE To determine whether the balloon-expandable device is...

Impregnation of expandable graphite (EG) after thermal treatment with an epoxy resin containing surface-active agents (SAAs) enhanced the intercalation of epoxy monomer between EG layers and led to further exfoliation of the graphite, resulting in stacks of few graphene layers, so-called "stacked" graphene (SG). This process enabled electrical conductivity of cured epoxy/SG composites at lower ...

in this research, graphene was synthesized by chemical vapor deposition (cvd) method in atmosphere pressure (14.7 psi). different functionalization method was used for oxidizing of graphene such as acid and alkaline treatments. the functionalized graphene (fg) was characterized by ftir and raman spectroscopy. nanofluid with water and different concentration (0.05, 0.15 and 0.25 wt %) of fg were...