Divya Sachdev; Sandeep Singh;Renu Pasricha; Shweta Gupta; Veeresh Kumar
Abstract
Surface tension mediated U-shaped interlinked diammine network (spermine) assembled at the air-water interface, when interacted with aqueous functionalized gold nanoparticles (AuNPs), form ring like nanogold structures. These electrostatic force guided self-assembies of the ligand diammine with gold ...
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Surface tension mediated U-shaped interlinked diammine network (spermine) assembled at the air-water interface, when interacted with aqueous functionalized gold nanoparticles (AuNPs), form ring like nanogold structures. These electrostatic force guided self-assembies of the ligand diammine with gold provides a facile route for control on the nanostructure formation while portraying double linkage ability of the diammine (here spermine). Pressure-area isotherm of controlled multilayer formation of spermine linked gold NPs (spermine-AuNPs) were studied and characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy and Transmission electron microscopy (TEM). The TEM micrographs clearly elucidate the formation of ring like networks of gold NPs under the influence of spermine. Furthermore we believe that these spermine-AuNPs will surely have supportive role as a bio-diagnostic material for ultra-sensitive biological detection and pave way for a novel route for assembly fabrication.
Andrew T. Becker; Alan M. Russell; L. Scott Chumbley
Abstract
Anhydrous ammonia is a toxic material that is transported from distribution centers to farm fields in steel pressure vessels called nurse tanks. Numerous accidents have occurred in which nurse tanks failed and ammonia was released, often with explosive force. The majority of such accidents are caused ...
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Anhydrous ammonia is a toxic material that is transported from distribution centers to farm fields in steel pressure vessels called nurse tanks. Numerous accidents have occurred in which nurse tanks failed and ammonia was released, often with explosive force. The majority of such accidents are caused by stress corrosion cracking of the tank steel. Stress corrosion cracking is caused by the combination of stress in the tank's steel and the corrosive effect of ammonia. Neutron diffraction analysis was used to map the residual stress state in and near circumferential welds from two used anhydrous ammonia nurse tanks, one manufactured in 1966 and the other manufactured in 1986. Notched SA455 steel test specimens were held under tensile load (stress concentration factors of 40 to 80 MPa·√m) while immersed in NH3 for seven months to generate crack propagation rate data. The results from these measurements were then used to predict stress corrosion crack growth rates for various pre-existing crack sizes at various temperatures. These data may be useful for estimating safe service lifetimes of nurse tanks that contain cracks.
