The split-pulse laser method is used to reinvestigate the optical attenuation of distilled water in the region from 430 to 630 nm. The studies are then extended to ionic solutions of NaCl, MgCl(2), and Na(2)SO(4), these salts forming the major constituents of seawater. The effect of the concentration of these constituents on optical attenuation is investigated. Further, optical attenuation stud...

Measurements of the natural propagation of UHF radio waves on an underground train are reported. Of prime interest are the natural propagation attenuation and the median signal level behavior. The propagation attenuation rates or the median signal level behaviors are found to correlate with the train carriages and frequency. On the front carriage, the propagation attenuation rate is 54 dB/100 m...

Subsequent to modeling of natural attenuation processes to predict contaminant trends and plume dynamics, monitoring data were used to evaluate the effectiveness of natural attenuation at reducing contaminant concentrations in groundwater at seven fuel-contaminated sites. Predicted and observed contaminant trends at seven sites were compared in order to empirically assess the accuracy of some f...

Contamination in subsurface environment is a serious environmental hazard. Main sources of the contamination are petrol, diesel fuel, gasoline at oil refineries, underground storage tanks, transmission pipelines and different industries. Permeable reactive barriers (PRBs), which promising technology to remediate groundwater in-situ, filled with materials for removal contaminants present groundw...