Homogeneous and inhomogeneous ignition modes of n-heptane were studied using high-speed imaging in a high-pressure shock tube (HPST). n-Heptane, fuel with strong negative temperature coefficient (NTC) behavior, was mixed 4%-21% oxygen argon or nitrogen ignited over wide range (700–1250 K) at elevated pressures (> 10 atm). Ultraviolet (UV) images OH* emission captured through sapphire shock-tube...

Homogenous charge compression ignition (HCCI) combustion is spontaneous multi-site combustion of a nominally premixed air/fuel mixture that exhibits high rate of pressure rise and short combustion duration. To avoid excessive pressure rise rate and knocking, HCCI engines are fueled with highly diluted mixture using a combination of excess air and/or EGR. HCCI combustion is attractive due to ...

The synthesis of a series of C1-symmetric metallocene complexes rac-[1-(5,6-dialkoxy-2-methyl1-η5-indenyl)-2-(9-η5-fluorenyl)ethane]zirconium dichlorides (alkyl: n-butyl, n-hexyl, n-octyl, ndecyl) is described. These complexes are versatile catalysts in the polymerization of propylene after in situ activation with triisobutylaluminum (TIBA) and Ph3C[B(C6F5)4] in toluene and heptane solution. Al...

For many years, commercial-grade hexane has been the preferred solvent for extracting oil from cottonseed. Recent environmental and health concerns about hexane may limit the use of this solvent; therefore, the need for a replacement solvent has become an important issue. Heptane is similar to hexane, but does not have the environmental and health concerns associated with the latter. On a labor...