Groundbased ionograms measure the Chapman scale height HT at the F2-layer peak that is used to construct the topside profile. After a brief review of the topside model extrapolation technique, comparisons are presented between the modeled profiles with incoherent scatter radar and satellite measurements for the mid latitude and equatorial ionosphere. The total electron content TEC, derived from measurements on satellite beacon signals, is compared with the height-integrated profiles ITEC from the ionograms. Good agreement is found with the ISR profiles and with results using the low altitude TOPEX satellite. The TEC values derived from GPS signal analysis are systematically larger than ITEC. It is suggested to use HT , routinely measured by a large number of Digisondes around the globe, for the construction of the IRI topside electron density profile.

Photoluminescent graphene oxide particles (PGOPs) were synthesized by hydrothermal treatment. The relative transmission spectra of the PGOPs in the infrared region between 800 cm?1 and 4000 cm?1 showed frequencies that characterize chemical species such as ethers (C[sbnd]O), ketones (CO[dbnd]), carboxylic acids (COOH), double bonds of carbon (C[dbnd]C) and water (H2O). The emission wavelengths were 568 nm for graphene oxide with green photoluminescence (GOGP) and 634 nm for graphene oxide with orange photoluminescence (GOOP) when excited with a light source of 375 nm. Moreover, the detection of light emission at 600 nm in the photoluminescent excitation (PLE) spectrum is detected with more intensity in GOGP than GOOP due to the presence of groups C[dbnd]C and carboxylates ions ([sbnd]COO?) linked to graphene (GN) and the photon effective emission time according to the decay profile for e...