difference between fanning friction factor and darcy friction factor
Fanning friction factor This friction factor is one-fourth of the Darcy friction factor, so attention must be paid to note which one of these is meant in the "friction factor" chart or equation consulted. Of the two, the Fanning friction factor is the more commonly used by chemical engineers and those following the British convention.
Configuration factor In dentistry, the configuration factor was first introduced by Davidson CL,1986, and later quantitavly extended Feilzer et al. in 1987 and refers to the number of bonded surfaces to the number of un-bonded surfaces in a dental restoration. For example, for a class I preparation there would be 5 bonded surfaces and only 1 un-bonded surface; the net result would be a c-factor of 5. With an increasing C factor the developing curing contraction stresses of bonded restorations (resin composites) increases too (Feilzer et al. 1987). The developing curing contraction in a bonded restoration generate stress on the bonded interface that are in competition with the developing bond strength of the setting restorative to the cavity surfaces, which may result in (partial) debonding, marginal leakage and post-operative pain (Davidson et al. 1984).