We calculate the intersubband and intrasubband many-body inelastic Coulomb scattering rates due to electron-electron interaction in two-subband semiconductor quantum wire structures. We analyze our relaxation rates in terms of contributions from interand intrasubband charge-density excitations separately. We show that the intersubband (intrasubband) charge-density excitations are primarily resp...

Successful empirical modeling of the topside ionosphere relies on the availability of good quality measured data. The Alouette, ISIS and Intercosmos-19 satellite missions provided large amounts of topside sounder data, but with limited coverage of relevant geophysical conditions (e.g., geographic location, diurnal, seasonal and solar activity) by each individual mission. Recently, methods for i...

[1] A retrospective study of the North-South asymmetry (NSA) during the solstices is made using the different geospace parameters in the North and South magnetic hemispheres. The NSA features are investigated using Total Electron Content, TEC, and Global Electron Content, GEC, produced from global ionospheric maps, GIM-TEC for 1999-2013, the Ionospheric Electron Content, IEC, measured by Topex-...

Orbital-free (OF) density functional theory (DFT) directly solves for the electron density rather than the wave function of many electron systems, greatly simplifying and enabling large scale first principles simulations. However, the required approximate noninteracting kinetic energy density functionals and local electron-ion pseudopotentials severely restrict the general applicability of conv...

A new scheme for constructing approximate effective electron potentials within density-functional theory is proposed. The scheme consists of calculating the effective potential for a series of reference systems, and then using these potentials to construct the potential of a general system. To make contact to the reference system the neutral-sphere radius of each atom is used. The scheme can si...

Vertical electron density profile is an important source of information on the Earth’s ionosphere. It is well known that such vertical electron density profile can be retrieved using LEO (Low Earth Orbit) satellite RO (radio occultation) data. With more and more LEO satellite data available (such as CHAMP, SAC_C, GRACE, COSMIC), the retrieved vertical electron density can be more accurate if so...

SUePDF is a graphical user interface program written in MATLAB to achieve quantitative pair distribution functions (PDFs) from electron diffraction data. The program facilitates structural studies of amorphous materials and small nanoparticles using electron diffraction data from transmission electron microscopes. It is based on the physics of electron scattering as well as the total scattering...

We present first-principles approaches based on density functional theory for calculating positron states and annihilation characteristics in condensed matter. The treatment of the electron-positron correlation effects (the enhancement of the electron density at the positron with respect to mean-field density) is shown to play a crucial role when calculating the annihilation rates. A generalize...

Abbreviations: BOD: biochemical oxygen demand COD: chemical oxygen demand OD: optical density OW: optimized wastewater PNSB: purple non sulphur photosynthetic bacteria ROW:raw optimized wastewater RW: raw wastewater SCP: single cell protein SEM: scanning electron microscope SOW: sterile optimized wastewater SW: sterile wastewater TEM: transmission electron microscope TKN: total kjeldahl nitroge...