Search results for " irradiation"

Thermal bleaching of gamma-induced-defects in optical fibers

2012

International audience; Ge-doped and F-doped gamma-irradiated fibers with a maximum accumulated dose of 10 MGy were subjected to isochronal annealing treatments up to 750°C. The thermal treatment influence on the point defect generation and transformation were investigated through Radiation Induced Attenuation (RIA) changes in the visible and IR spectral domains. The thermal bleaching of gammainduced-defects depends on both temperature and composition of optical fibers.

Radiation induced generation of Non-Bridging Oxygen Hole Center: intrinsic and extrinsic processes

2006

On the mechanism of radiation synthesis of nanogels

2016

Radiation-engineered poly(N-vinyl pyrrolidone) nanogels are very interesting biocompatible nanocarriers for i.v. administration of therapeutics and contrast agents for bioimaging among other applications. Nanogels are usually produced upon irradiation of dilute aqueous polymer solutions. Under these conditions, the polymer radicals formed primarily react via intramolecular radical-radical combination forming intramolecular crosslinks. The manufacturing process is fast and effective and grants excellent control of particle size and simultaneous sterilization of the formed nanogels. Interestingly, primary amino groups and carboxyl groups, useful for (bio)conjugation, are also formed in a dose…

Photoluminescence properties of S2 molecule trapped in Melanophlogite

2015

We studied the photoluminescence properties of a sample of SiO2-clathrate Melanophlogite, a crystalline microporous material which is found in nature as a rare mineral. Upon β irradiation, the material displays an intense light emission under near-UV illumination. We studied in detail this optical activity by steady-state and time-resolved photoluminescence measurements as a function of temperature. The spectroscopic properties we find can be ascribed to a population of quasi-free molecules trapped within each of the two different types of cage available in the structure of this clathrate, although the spectroscopic properties of the guest molecules are affected by their interactions with t…