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.
Evaluation of Methods for Monitoring Landfill Barriers
Physical principles of methods and systems are being described and discussed with respect to their applicability for long term reliable control of different barriers. Emphasis is put on the detection and localization of leakages.
Avian infectious bronchitis.
Avian infectious bronchitis (IB) is caused by the gammacoronavirus infectious bronchitis virus (IBV). The virus causes infections mainly in chickens and is a significant pathogen of commercial meat and egg type birds. IB is an acute, contagious disease characterised primarily by respiratory signs in growing chickens. In hens, decreased egg production and quality are often observed. Some strains of the virus are nephropathogenic and produce interstitial nephritis and mortality. The severity of IBV-induced respiratory disease is enhanced by the presence of other pathogens, including bacteria, leading to chronic complicated airsacculitis. Diagnosis of IB requires virus isolation or demonstration of viral nucleic acid from diseased flocks. Demonstration of a rising serum antibody response may also be useful. The widespread use of live and inactivated vaccines may complicate both the interpretation of virus isolation and serology findings. The occurrence of antigenic variant strains may overcome immunity induced by vaccination.