  We have used Simple Denoising Algorithm using Wavelet Transform on the
monthly solar neutrino flux data from (1) SAGE detector during the period from
1st January 1990 to 31st December 2000; (2) SAGE detector during the period
from April 1998 to December 2001; (3) GALLEX detector during the period from
May 1991 to January 1997; (4) GNO detector during the period from May 1998 to
December 2001; (5) GALLEX-GNO detector (combined data) from May 1991 to
December 2001 and (6) average of the data from GNO and SAGE detectors during
the period from May 1998 to December 2001. (1) exhibits periodicity around 20,
27, 36, 70, 90 and 114 months. (2) shows periodicity around 21, 28, 31 and 33
months. For (3) we observe periodicity around 24, 40, 54, 57, 59, 62 and 64
months. For (4) periodicity is seen around 23, 30 and 34 months. (5) gives
periodicity around 49, 57, 64, 74, 79, 88, 95 and 99 months while (6) shows
periodicity around 24, 32, 35 and 38 months. We have found almost similar
periods in the solar flares, sunspot data, solar proton data which indicates
that the solar activity cycle may be due to the variable character of nuclear
energy generation inside the sun.
