The first observations of UV (290–400 nm) ever made at an agro-meteorological/radiometric station located in the metropolitan region of Maceió (9°28′S, 35°49′W, 127 m), Northeast Brazil, during 2008 are reported in this work. Solar UV radiation variability in different time scales and...

This work proposes an heuristic indicator for mid-term tendencies of stock prices based on non-linear dynamic equations combined with a graphical method inspired on cell morphology analysis. The model consists of ordinary differential equations with parameters that are fitted by means of the...