Vertical variance analysis of geomagnetic disturbance during solar cycle 23

300-309The geomagnetic field consists of temporal variations induced primarily by the variations in the solar wind and embedded interplanetary magnetic field. 34 stations across the Earth have been categorized in this paper on the basis of their geomagnetic disturbance during solar cycle 23 (1997-2008). The Vertical Variance (VV) disturbance quantifier has been used to develop such profile. The latitude profile of geomagnetic disturbance has been found to exhibit a typical ‘Knee’ behaviour, with the fluctuation content seen to rise sharply beyond this critical latitude determined near 52° latitude. The increasing trend in geomagnetic fluctuation content however is seen to end around the auroral oval beyond where abrupt variations has been observed indicating the transition from closed to open magnetic field lines. The physical mechanism behind this trend has also been explored. The VV analysis of geomagnetic disturbance has revealed prominent features of solar wind – magnetosphere coupling

Vertical variance analysis of geomagnetic disturbance during solar cycle 23

The geomagnetic field consists of temporal variations induced primarily by the variations in the solar wind and embedded interplanetary magnetic field. 34 stations across the Earth have been categorized in this paper on the basis of their geomagnetic disturbance during solar cycle 23 (1997-2008). The Vertical Variance (VV) disturbance quantifier has been used to develop such profile. The latitude profile of geomagnetic disturbance has been found to exhibit a typical 'Knee' behaviour, with the fluctuation content seen to rise sharply beyond this critical latitude determined near 52° latitude. The increasing trend in geomagnetic fluctuation content however is seen to end around the auroral oval beyond where abrupt variations has been observed indicating the transition from closed to open magnetic field lines. The physical mechanism behind this trend has also been explored. The VV analysis of geomagnetic disturbance has revealed prominent features of solar wind – magnetosphere coupling

Influence of IMF Bz on the variability of the minimum value of fo-F2

46-50The critical frequency of the ionosphere, apart from the diurnal and annual variations exhibit day-to-day variations. The minimum value of fo-F2 around the pre-sunrise period also has a day-to-day change. In this work, the relation between the magnitude of fo-F2 minimum and h′F2 values around the pre-sunrise period and their relation with the sign of the north-south component of the interplanetary magnetic field (IMF) is investigated. The minimum value of fo-F2 for each day is found to be related to the IMF north-south component, with the fo-F2 value tending to be larger when the IMF is northward and smaller when the IMF is southward. The northward IMF Bz is seen to produce an eastward electric field at the ionosphere and move the ionospheric plasma to higher altitudes resulting in higher critical frequencies. Whereas a southward IMF Bz produce a westward electric field and move the ionospheric plasma to lower altitudes resulting in lower critical frequencies

Characterization and In vitro biocompatibility analysis of nanocellulose scaffold for tissue engineering application

Tissue engineering aims to exploit the regenerative capacity of cells and connect the inherent ability of the body to repair and regenerate. Cells are seeded onto a porous three-dimensional scaffold in tissue engineering, which will provide protection and direct cells to the development of new tissue-like structures. These scaffolds can provide a medium for the delivery, under controlled conditions of growth factors release and drug delivery. Herein, nanocellulose was extracted from Ixora coccinea L. plant root, plasticized scaffold of nanocellulose were prepared by using glycerol, gelatin, and PEG 600 followed by morphological characterized by FTIR, XRD, SEM, and tensile modulus analysis. FTIR indicated extracted nanocellulose is without any hemicelluloses, lignin, and non-cellulosic materials. XRD data displayed the extracted nanocellulose has a crystal size of around 3.6 nm while SEM data revealed the fiber diameter was around 20 µm. In the tensile modulus analysis, 1% PEG 600 exhibited the highest (tensile strength 69 MPa with young’s modulus 67.326 MPa) as compared to glycerol and gelatin and hence selected for further studies. The In vitro cytocompatibility studies revealed that nanocellulose and 1% PEG 600 incorporated nanocellulose scaffolds were cell-friendly, promote cell proliferation, and do not show RBC aggregation as well as haemolysis suggesting its potential in various tissue engineering applications. The novelty of this work is that the nanocellulose extracted from the root of I. coccineahas traditional medicinal values in Ayurveda