Researchers are developing a nano-material they hope will pinpoint exact locations of structural strain; the nanomaterial will self-diagnose dynamically and measure the strain. Image: Courtesy Nanosi Advanced Technology Inc. Top sample contains imbedded fluorescent silicon nanoparticles; the bottom sample doesn’t. The material is fluorescent silicon nanoparticles (Si-NP), and the research seeks to validate relationships between the Si-NP fluorescence peak and the macro-level state of strain. The success of the research revolves around a phenomenon known as the Stokes shift, which refers to the longer wavelength of electromagnetic energy emitted as a result of losing some absorbed energy, says Charles Marsh,
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.