Studying travelling ionospheric disturbances from near-vertical ionosphere sounding with high temporal resolution
In this study, we analyze the near-vertical ionospheric sounding data obtained with a multipurpose digital chirp ionosonde. The ionosonde was recording ionograms once each minute. We analyzed the results of processing the datasets over three observational years from 2010 to 2012. Obtaining ionograms with a high temporal resolution allowed us to trace the dynamics and evolution of additional traces referred to as “cusps”, and also to combine ionograms with such traces into sequences. The percentage of ionograms containing cusps proved to be more than 10% of the overall number of ionograms. Thus, during daytime, the rate surpasses 30%, whereas, during nighttime, such ionograms are practically absent. The typical cusp lifetime proved to be 4-15 min, therefore, disturbed ionograms are much more rarely detected with standard vertical sounding ionosondes. The presence of such traces unambiguously evidences significant electron density horizontal gradients caused by travelling ionospheric disturbances (TIDs) with scales up to 50 km.
Studying of the spatial–temporal structure of wavelike ionospheric disturbances on the base of Irkutsk incoherent scatter radar and Digisonde data
Abstract In this paper the spatio-temporal structure of traveling ionospheric disturbances characteristics is studied on the base of the electron density profiles measured by two beams of the Irkutsk incoherent scatter radar and the Irkutsk Digisonde. The technique for determination of spatial–temporal structure of wavelike ionospheric disturbances was developed using cross-correlation and spectrum analysis of electron density. The automated method for extracting ionospheric disturbances including both long-period day-to-day variability and short-period variations has been developed. Full analyses of January 15–February 17, 2011 data, including total velocity vector, was carry out for 1–6 h ionospheric disturbances, corresponding to internal gravitational waves. The propagation characteristics agree with those obtained from the known studies of the wavelike ionospheric disturbances. An automated method of ionospheric disturbances analysis was created on the basis of regular continuous measurements with the Irkutsk Digisonde. The statistical analysis of electron density disturbances was carried out for 2004–2009 period.
Adsorption of immunoglobulin Y in supermacroporous continuous cryogel with immobilized Cu(2+) ions.
The influence of temperature, pH and ionic strength on the adsorption of Immunoglobulin Y (IgY) in IDA-Cu(2+) cryogel system was studied by batch equilibrium measurements. The adsorptive equilibrium data were obtained at 17 and 27°C, pH 5.0 and 6.5, and at ionic strength of 50 and 200mmolL(-1) NaCl. Langmuir, Freundlich and Langmuir-Freundlich models were fitted to equilibrium data, while the enthalpy of adsorption of IgY in IDA-Cu(2+) cryogel system was calculated through Van't Hoff analysis. The binding of IgY on cryogel was stronger at 27°C and lowest pH and ionic strength values, with apparent maximum adsorption capacity of 27mgg(-1). The adsorption of protein in the resin was spontaneous in all analyzed cases. The results provide valuable information to enable the improvement of IgY purification processes.