This paper presents the development of an Artificial Neural Network electron density profiler based on electron density profiles collected from radio occultation (RO) measurements from LEO (Low Earth Orbit) satellites to improve the spatial and temporal modeling of ionospheric electron density over Europe. The significance in the accurate determination of the electron density profile lies on th...

A new tool has been developed to aid in the visualization of electron density in crystals or from quantum chemistry calculations. It displays the fine details of the electron density on a plane and the three-dimensional model of the molecule at the same time. The program enables the user to examine the details of weak or irregular features. Such features frequently occur in low-resolution maps,...

High-resolution temporal observations performed with the SUMER spectrometer on SoHO provide an opportunity to investigate the electron density variations in thèquiet Sun' solar transition region due to UV transient events. Two datasets obtained in the density sensitive lines belonging to the O iv 1400 A multiplet were searched for such events, leading to the identiication of two explosive event...

The charge density (CD) distribution of an atom is the difference per unit volume between the positive charge of its nucleus and the distribution of the negative charges carried by the electrons that are associated with it. The CDs of the atoms in macromolecules are responsible for their electrostatic potential (ESP) distributions, which can now be visualized using cryo-electron microscopy at h...

A systematic search approach to the automatic refinement of protein structures could reduce the need for manual intervention. In this approach, possible conformations for a segment of the polypeptide chain are generated systematically and the trial segments are scored for their agreement with the observed diffraction data. The sampling of conformational space is sufficiently exhaustive that rea...

HDPE monofilaments were obtained using different extruders and drawn by post-extruder equipments. After solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 MeV electron beams in air at room temperature at 25, 50, 75, 100 and 125 kGy dose ranges to induce a network structure. HDPE crosslinking was studied on the basis of gel content measurements. The fibers w...

Molecular replacement is a powerful tool for the location of large models using structure-factor magnitudes alone. When phase information is available, it becomes possible to locate smaller fragments of the structure ranging in size from a few atoms to a single domain. The calculation is demanding, requiring a six-dimensional rotation and translation search. A number of approaches have been dev...

The commonly used validation metrics for the local agreement of a structure model with the observed electron density, namely the real-space R (RSR) and the real-space correlation coefficient (RSCC), are reviewed. It is argued that the primary goal of all validation techniques is to verify the accuracy of the model, since precision is an inherent property of the crystal and the data. It is demon...

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