The ability of the US Environmental Protection Agency’s Community Multi-scale Air Quality (CMAQ) model to simulate the wet deposition of ammonium during 8-week winter and summer periods in 2001 is evaluated using observations from the National Acid Deposition Program (NADP) monitoring sites. The objective of this study is to ascertain the effects of precipitation simulations and emissions on CM...

manganese oxide nanoparticles (mn3o4-nps) were prepared using precipitation method. the prepared nanoparticles were characterized by a number of techniques, including x-ray diffraction (xrd) analysis, scanning electron microscopy (sem), transmission electron microscopy (tem) and fourier transforms infra red (ft-ir) spectroscopy. the xrd pattern showed that the structure of mn3o4-nps was tetrago...

Contrasting metabolic regimes operate in Opuntia basilaris Engelm. and Bigelov, before and after precipitation. During periods of drought, atmospheric CO(2) exchange and transpiration are greatly reduced throughout the day/night cycle by stomatal closure and a highly impervious cuticle. The hypothesis is that endogenously produced CO(2) is retained and recycled through dark CO(2) fixation, orga...