2,4-dinitrophenylhydrazanomethylphenol (dnphmp) was immobilized onto silicate rice husk ash to form a heterogeneous catalyst denoted as rhdnph. the elemental and edx analysis of rhdnph showed the nitrogen is incorporated into silica. the rhdnph had 154.6 m2g-1 as a specific surface area. the ft-ir clearly showed the appearance of –nh and c=n absorption band at the expected range. the tga curve ...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

dumpsites can produce serious pollution problems in soil, water and air, and are the most frequent method of solid waste disposal in many developing countries. one of the pollution concerns at dumpsites is the emission of methane, which has been identified as a green house gas. in order to determine the surface emission of methane at an informal settlement built on a former dumpsite, six sampli...

a hydrothermal method for preparation of nano-size zirconia has been studied to optimize the effective parameters (precursor concentration, temperature and time) using response surface methodology (rsm). the synthesized zirconia samples were characterized through x-ray diffraction (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) analyses to identify mean nano...

the aisi 316 l stainless steel (ss) specimens were exposed to passivation surface through two different processes including; holding in 40-vol% hno3 at temperature of 60 ºc for 30 min and 15-vol%h2so4 at ambient temperature for 1 hour. the corrosion behavior of specimens was evaluated in physiological solutions by electrochemical in vitro tests through linear and tafel polarization tests. cycli...