EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF PULSED LASER ENERGY TRANSMISSION THROUGH THE ATMOSPHERE

An experimental study has been conducted and compared with a computed numerical model in order to determine the limitations induced by the air breakdown on the transmission of a high energy laser pulse through the standard atmosphere. The 10.6 µm CO2 laser displays up to 300 J in a 2.5 µsec pulse with a high power peak (typically 5x108 W ; 50 ns F W H M) followed by a high energy tail. The laser beam is focused by means of a 5 X telescope at 67.5 m (f/D = 135) outside the laboratory. Envelope of the beam and energy density distribution in the focal plane are presented. Aerosol concentration and size distribution measurements are obtained by means of a particle optical counter (Knollenberg axially scattering spectrometer probe : 0.5 µm 45 µm). Energy and fluence transmitted through the air breakdown - induced plasma for given atmospherical conditions are measured as a function of time and incident fluence and then compared with results of a computed numerical hydrodynamic bi-dimensional model

Why Some Exotic Species Are Deeply Integrated into Local Cultures While Others Are Reviled

One key challenge for invasive species management is finding support from local communities. Without local support, management plans can be severely compromised. What makes people support or reject management of invasive species can be linked to their perception of the target invasive species. In other words, it can be harder to control invasive species that are assimilated into the local community. We identify five factors associated with how quickly invasive species can become culturally assimilated. These factors are arrival time, economic impact, aesthetic value, effect on human health, and origin of nonnative species and of human immigrants. We suggest that understanding how these factors contribute to the incorporation of nonnative species into local cultures is important in determining effective control measures. In this vein, publicly accessible educational programs explaining the problems that invasive species produce will be required to implement effective invasive species management.Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Dimarco, Romina Daniela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Simberloff, Daniel. University of Tennessee; Estados Unido