The electron--electron scattering does not affect the electrical current in Galilean--invariant systems. We show that nevertheless collisions may contribute to electric resistivity of systems with parabolic spectrum provided they have multiply connected Fermi surface and there is an additional mechanism scattering. To this end, we calculate a two-dimensional electron gas two filled transverse s...

      In this research, TiO2 nanoparticles were synthesized by a simple wet chemical method. TiCl4 was used as precursor in hydrogen peroxideand ethanol. The TiO2 nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), electron dispersive spectroscopy (EDS) and UV-Vis spectrophotome...

background: one of the main problems of dedicated iort accelerators is to determine dosimetric characteristics of the electron beams. monte carlo simulation of iort accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry. materials and methods: liac accelerator head was modeled using the beamnrcmonte carlo simulation system. phase-space files were generated a...

background: megavoltage beams used in radiotherapy are contaminated with secondary electrons. different parts of linac head and air above patient act as a source of this contamination. this contamination can increase damage to skin and subcutaneous tissue during radiotherapy.  monte carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

Copper vanadate nanostructures were prepared via ex-situ precipitation approach in presence of Schiff-base ligand (N,N׳ -buthylenebis(acetylacetone iminato)dianion = acacbn) as a new capping agent. The effect of different Cu sources and pH on the size, morphology and size distribution of copper vanadate nanostructures was investigated. The as-prepared products were characterized using X-ray dif...

We re-examine MSW solutions of the solar neutrino problem taking (a) the results on total rates and the electron energy spectrum from the 825 day SuperKamiokande (SK) data, (b) those on total rates from the Chlorine and Gallium experiments, and (c) moments of the SK electron spectrum. A salient feature of our analysis is the inclusion of the correlations between the theory errors in the global-...

the development of green approaches for the biosynthesis of silver nanoparticles (agnps) is of prime significance in the field of nanotechnology research. a fast and eco-friendly protocol for the biosynthesis of extracellular agnps using culture supernatant (cs) from the fungus cunninghamella phaeospora was studied in this work. this cs was proved as a potential new source for the extracellular...

Spontaneous radiation emitted from relativistic electrons undergoing betatron motion in a plasma-focusing channel is analyzed, and applications to plasma wake-field accelerator experiments and to the ion-channel laser (ICL) are discussed. Important similarities and differences between a free electron laser (FEL) and an ICL are delineated. It is shown that the frequency of spontaneous radiation ...

We perform a propagation calculation for cosmic ray electrons and positrons using a three-dimensional di usion model, and use the resulting interstellar total electron spectrum to obtain the galactic di use photon spectrum due to inverse Compton, synchrotron and bremsstrahlung interactions consistently from radio to PeV energies. By considering the observed galactic non-thermal emission, we con...

FOX-7 (1,1-diamino-2,2-dinitroethylene) recently is expected as a relatively new energetic material with high-performance and low sensitivity. The RHF and MP2 levels and DFT method with B3LYP functional with aug-cc-pVDZ basis set have been used for obtaining equilibrium geometry and Rho function (electron density distribution). By the aid of fundamental physical theorems implemented in the ...