We perform ab initio calculations within the Landauer formalism to study the influence of doping on the conductance of surface-passivated silicon nanowires. It is shown that impurities located in the core of the wire induce a strong resonant backscattering at the impurity bound state energies. Surface dangling bond defects have hardly any direct effect on conductance, but they strongly trap bot...

[1] The surface of Jupiter’s moon Europa is peppered by topographic domes, interpreted as sites of intrusion and extrusion. Diapirism is consistent with dome morphology, but thermal buoyancy alone cannot produce sufficient driving pressures to create the observed dome elevations. Instead, diapirs may initiate by thermal convection that induces compositional segregation. Exclusion of impurities ...

We present a theoretical study of the spin-dependent electron scattering from screened impurities in III–V semiconductor quantum wells. The effective one band Hamiltonian and the Rashba spin-orbit interaction are used. We calculated the Mott scattering cross-section and the Sherman function for two-dimensional electrons spin-polarized parallel to the z-axis (direction of structure growth). We h...

Barnidipine hydrochloride is a long term dihydropyridine calcium channel blocker used for the treatment of hypertension. During the process development of barnidipine hydrochloride, four barnidipine impurities were detected by high-performance liquid chromatography (HPLC) with an ordinary column (Agilent ZORBAX Eclipse XDB-C18, 150 mm×4.6 mm, 5 µm). All these impurities were identified, synthes...

determination of the amount of sugar in sugar beet is usually accomplished by polarimetric method in sugar industry. this method is not accurate due to impurities such as sodium, potassium and amino-nitrogen that are present and might cause some errors in the evaluation of the technical quality of sugar beet. in this research, 7309 samples of sugar beet from two semi- arid county, isfahan and c...

We study the Tomonaga-Luttinger model in the presence of magnetic (Kondo-like) impurities. By using a recently proposed field-theoretical approach to non-local bosonization we obtain the effective action describing the low-energy charge and spin density fluctuations. From this action the dispersion relations of the collective modes are readily found. We also compute the momentum distribution an...

Genotoxic compounds induce genetic mutations and/or chromosomal rearrangements and can therefore act as carcinogenic compounds (McGovern and Jacobson-Kram, 2006). These compounds cause damage to DNA by different mechanisms such as alkylation or other interactions that can lead to mutation of the genetic codes. In general, chemists employ the terms "genotoxic" and "mutagenic" synonymously; howev...

Using DFT + U calculations, the crystal structure and electronic properties of nonmetal co-doping with sulfur in anatase TiO2 are systematically investigated. The initial purpose of this work is to improve the photocatalytic performance of S mono-doped TiO2, in which S occupies the lattice Ti site and acts as a recombination center. Among eight nonmetal impurities that occupy the interstitial s...