the preparation of air–fuel mixture is considerably dependent on fluid flow dynamics to achieve improved performance, efficiency, and engine combustion in the appearance of flow. in this study, the effects of mixtures of hydrogen and compressed natural gas (cng) on a spark ignition engine are numerically considered. this article presents the results of a direct-injection engine using methane–hy...

in the present work, a titanium-based ziegler-natta catalyst was employed to synthesize ultra molecular weight polyethylene in a slurry medium. the effect of different parameters such as ethylene pressure, temperature, catalyst composition, and hydrogen pressure was studied. as the results indicate, increasing either [al]/[ti] ratio or temperature causes polymerization rate to go through a maxi...

We optimized the geometries of the graphene and graphene with hydrogen using PW91VWN, PWCIPL,MPWLYP, G96LYP, G96141.0-210.6-310, 6-31G*Ievels of theory and compared our results with each other.We present the most important structural parameters determined for the addition of a hydrogen atom tographene and the outward movement of the carbon atom that is bonded to hydrogen is 0.48 A Also wecalcul...