85 research outputs found
Resonant Magnetic Vortices
By using the complex angular momentum method, we provide a semiclassical
analysis of electron scattering by a magnetic vortex of Aharonov-Bohm-type.
Regge poles of the -matrix are associated with surface waves orbiting around
the vortex and supported by a magnetic field discontinuity. Rapid variations of
sharp characteristic shapes can be observed on scattering cross sections. They
correspond to quasibound states which are Breit-Wigner-type resonances
associated with surface waves and which can be considered as quantum analogues
of acoustic whispering-gallery modes. Such a resonant magnetic vortex could
provide a new kind of artificial atom while the semiclassical approach
developed here could be profitably extended in various areas of the physics of
vortices.Comment: 6 pages, 7 figure
Use of viral pathogens and indicators to differentiate between human and non-human fecal contamination in a microbial source tracking comparison study
Assays for the detection and typing of adenoviruses, enteroviruses and F+ specific coliphages were performed on samples created as part of a national microbial source tracking methods comparison study. The samples were created blind to the researchers, and were inoculated with a variety of types of fecal contamination source (human, sewage, dog, seagull and cow) and mixtures of sources. Viral tracer and pathogen assays demonstrated a general ability to discriminate human from non-human fecal contamination. For example, samples inoculated with sewage were correctly identified as containing human fecal contamination because they contained human adenovirus or human enterovirus. In samples containing fecal material from individual humans, human pathogen analysis yielded negative results probably because the stool samples were taken from healthy individuals. False positive rates for the virus-based methods (0-8%) were among the lowest observed during the methods comparison study. It is suggested that virus-based source tracking methods are useful for identification of sewage contamination, and that these methods may also be useful as an indication of the public health risk associated with viral pathogens. Overall, virus-based source tracking methods are an important approach to include in the microbial source tracking 'toolbox'
Comment: Response of underground multiconductor cable systems to external fields illumination
Comments on "Coupling of electromagnetic fields to underground cable transmission systems," by F. Han and S. Sali, Vol. 9, No. 7/8, 953_973, 1995
Numerical modelling of complex resistivity effects on a homogeneous half-space at low frequencies
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