Fabrication and electromagnetic characterization of novel self-metallized thin films
Unique, self-metallized films were investigated for deployable reflector antenna applications at L-band. Polyamic acid resins or soluble polyimides were doped with metal complexes, cast into films, and thermally cured. Each resulting film had a metallic layer on one side, adhering unfailingly to the polymer. Metallization was successful for silver or palladium in 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) and 4,4'- oxydianiline and for gold in BTDA and 2,2-bis[4-(4- aminophenoxy)phenyl]hexafluoropropane (4-BDAF) or the space durable polyimide, 2,2-bis(3,4-dicarboxyphenyl)- hexafluoropropane dianhydride and 4-BDAF (LaRCCP1). Reflectivity, transmissivity, and emissivity were determined, using an HP 8510 Vector Network Analyzer, to within 0.001 precision and accuracy. A custom-made test fixture/positioner, a thru-reflect-line calibration, and calculated reflection coefficients were used. The Ag film proved most suitable for further study, with 0.9957 reflectivity and 0.0042 emissivity. The Pd films were 0.89 reflective and 0.11 emissive; both Au films tested entirely transmissive. Transmission and scanning electron micrographs, S-parameters, and power coefficients are shown.
Inflatable antennas for portable direct satellite communication
Satellite-based communication system can provide access to voice, data, video and internet transmission that is independent of terrestrial infrastructure. This is particularly important in disaster response situations and military maneuvers where mobile p
Glycogen phosphorylase in lobster hepatopancreas: action of proteases on the enzyme
Abstract 1. 1. In lobster hepatopancreas, extracellular protreases cause the inactivation of glycogen phosphorylase. 2. 2. The proteolysis of glycogen phosphorylase purified from rabbit muscle by these proteases has been shown by SDS-polyacrylamide gel electrophoresis. 3. 3. A cell isolation technique has allowed us to remove proteases of extracellular digestion and to measure glycogen phosphorylase activity in lobster hepatopancreas. 4. 4. The glycogen phosphorylase activity seems to be mainly associated with R cells while it could not be detected in B cells.