Gh. Weiss et al., IMPROVED COMPUTATIONAL METHODS FOR THE CALCULATION OF KOHLRAUSCH-WILLIAMS WATTS (KWW) DECAY FUNCTIONS, Polymer, 35(9), 1994, pp. 1880-1883
Convergence-accelerating methods have been applied to series expansion
s for the stable-law density Q(alpha)(z) = 1/pi integral-infinity/0 e(
-ualpha) cos(zu) du which is, in turn, simply related to the spectral
density of the Kohlrausch-Williams/Watts (KWW) decay function phi(t)=e
-(t/tau)alpha]. N.m.r. relaxation parameters such as NOEF, T1 and T1rh
o are computed for polycarbonate and polydimethylsiloxane using the ne
w series and the results compared to experiment and to earlier computa
tions which employed a decomposition of the KWW function into a sum of
exponential terms.