Seismic noise subsoil in order to draw seismic microzonation maps showing the predicted ground response to earthquakes. Research on the origin of seismic noise indicates that the low frequency part of the spectrum (below 1 Hz) is due to natural causes, chiefly ocean waves. In particular the peak between 0.1 and 0.3 Hz is clearly associated with the interaction of water waves of nearly equal frequencies but opposite directions. At high frequency (above 1 Hz), seismic noise is mainly produced by human activities such as road traffic and industrial work; but there are also natural sources, like rivers. Around 1 Hz, wind
Antioxidant effect of polyphenols and natural phenols in the prevention or treatment of skin aging in humans are absent. Experiments on linoleic acid subjected to 2,2′-azobis (2-amidinopropane) dihydrochloride-induced oxidation with different combinations of phenolics show that binary mixtures can lead to either a synergetic effect or to an antagonistic effect. Antioxidant levels of purified anthocyanin extracts were much higher than expected from anthocyanin content indicating synergistic effect of anthocyanin mixtures. Antioxidant effect of polyphenols and natural phenols A polyphenol antioxidant is a type of antioxidant containing a polyphenolic substructure and studied in vitro. Numbering over 4,000 distinct species mostly from plants, many of these compounds have antioxidant