AMPA experimental communications systems

The program was conducted to demonstrate the satellite communication advantages of Adaptive Phased Array Technology. A laboratory based experiment was designed and implemented to demonstrate a low earth orbit satellite communications system. Using a 32 element, L-band phased array augmented with 4 sets of weights (2 for reception and 2 for transmission) a high speed digital processing system and operating against multiple user terminals and interferers, the AMPA system demonstrated: communications with austere user terminals, frequency reuse, communications in the face of interference, and geolocation. The program and experiment objectives are described, the system hardware and software/firmware are defined, and the test performed and the resultant test data are presented

Description of Nuclear Structure Effects in Subbarrier Fusion by the Interacting Boson Model

Recent theoretical developments in using the Interacting Boson Model to describe nuclear structure effects in fusion reactions below the Coulomb barrier are reviewed. Methods dealing with linear and all orders coupling between the nuclear excitations and the translational motion are discussed, and the latter is found to lead to a better description of the barrier distribution data. A systematic study of the available data (cross sections, barrier and spin distributions) in rare-earth nuclei is presented.Comment: 9 pages + 2 Figures (in eps form). To be published in the Proceedings of the FUSION97 Conference, South Durras, Australia, March 1997 (J. Phys. G). Full text and figures are also available at http://nucth.physics.wisc.edu/preprints/mad-nt-97-01.abs.htm

Gulls

Abundant gull (Figure 1) populations in North America have led to a variety of conflicts with people. Gulls cause damage at aquaculture facilities and other properties, and often collide with aircraft. Their use of structures on and near water results in excessive amounts of bird droppings on boats and docks. Their presence near outdoor dining establishments, swimming beaches, and recreational sites can lead to negative interactions with people. Large amounts of gull fecal material pollutes water and beaches resulting in drinking water contamination and swim bans. A combination of dispersal techniques, exclusion and limited lethal control may reduce damage to an acceptable level. No single management method to prevent gull conflicts works all the time or in all settings. Wildlife management methods should be integrated so that one method enhances the effect of another. For example, frightening devices often are more effective when done in conjunction with habitat modification (e.g., removal of food resources or roosting habitat) to make a site less attractive to gulls. Likewise, exclusion devices, such as overhead wires, work better when combined with covering or removing food resources. Gulls are classified as a migratory bird species and are protected by federal and, in most cases, state laws. In the United States, gulls may be taken only with a permit issued by the U.S. Fish and Wildlife Service. Occasionally, an additional permit is required from the state wildlife management agency. Permits are issued only after dispersal and other non-lethal damage management methods have been employed and proven ineffective at resolving the conflicts. No federal permit is needed, however, to frighten or mechanically exclude gulls