Multi-Parameters Study on Landfill Pole-Dipole Leak Detection
The theoretical model of pole- dipole landfill leak detection and the parameters that influence the location results are studied in this paper. Parametric curves for a single leak show that the greater the thickness of the media above the liner, and the greater the distance from dipole and HDPE, the lower of the detection sensitivity; in a certain range, expand the dipole spacing, leaks can be detected effectively. To identify and resolve multiple leaks, the potential measurements must be made close to the liner and the detector dipole spacing must smaller than the separation of the leak.
Tracer verification and monitoring of containment systems (II)
A tracer verification and monitoring system, SEAtrace{trademark}, has been designed and field tested which uses gas tracers to evaluate, verify, and monitor the integrity of subsurface barriers. This is accomplished using an automatic, rugged, autonomous monitoring system combined with an inverse optimization code. A gaseous tracer is injected inside the barrier and an array of wells outside the barrier are monitored. When the tracer gas is detected, a global optimization code is used to calculate the leak parameters, including leak size, location, and when the leak began. The multipoint monitoring system operates in real-time, can be used to measure both the tracer gas and soil vapor contaminants, and is capable of unattended operation for long periods of time (months). The global optimization code searches multi-dimensional {open_quotes}space{close_quotes} to find the best fit for all of the input parameters. These parameters include tracer gas concentration histories from multiple monitoring points, medium properties, barrier location, and the source concentration. SEAtrace{trademark} does not attempt to model all of the nuances associated with multi-phase, multi-component flow, but rather, the inverse code uses a simplistic forward model which can provide results which are reasonably accurate. The system has calculated leak locations to within 0.5 meters andmore » leak radii to within 0.12 meters.« less
Antimicrobial activity in pulp extract of Neem(Azadirachta indica Linn.)
Antimicrobialactivityin leaf extract of neem ( Azadirachta indica ) against human pathogenic bacteria. E.coli, Staphylococcus aureus, Pseudomonas aeruginosa , Salmonella typhimurium, Bacillus pumilus. Antimicrobia l activities of alcoholic extracts of neem leaves were used. Varying concent ration of each extracts 200mg/ml, 150 mg/ ml,100mg/ml, 50mg/ml, 25mg/ml prepared by using disc diffusion method. When compared with gentamycin 200mg and gentamycin 10mg, the methanol and ethanol extract shows maximum inhibition on Bacillus pumillus, Pseudomonas aeruginosa and Staphylococcus aureusin an asending order.