ABSTRACT
Spatial nonlocality affects the plasmonic characteristics of nanostructures. We used the quasi-static hydrodynamic Drude model to obtain the surface plasmon excitation energies in various metallic nanosphere structures. The surface scattering and radiation damping rates were phenomenologically incorporated into this model. We demonstrate that spatial nonlocality increases the surface plasmon frequencies and total plasmon damping rates in a single nanosphere. This effect was amplified for small nanospheres and higher multipole excitation. In addition, we find that spatial nonlocality reduces the interaction energy between two nanospheres. We extended this model to a linear periodic chain of nanospheres. Then we obtain the dispersion relation of surface plasmon excitation energies using Bloch's theorem. We also show that spatial nonlocality decreases the group velocities and energy decay lengths of the propagating surface plasmon excitations. Finally, we demonstrated that the effect of spatial nonlocality is significant for very small nanospheres separated by short distances.
ABSTRACT
We study the effect of structural inversion asymmetry, induced by the presence of substrates or by external electric fields, on charge transport in magnetic topological ultra-thin films. We consider general orientations of the magnetic impurities. Our results are based on the Boltzmann formalism along with a modified relaxation time scheme. We show that the structural inversion asymmetry enhances the charge transport anisotropy induced by the magnetic impurities and when only one conduction subband contributes to the charge transport a dissipationless charge current is accessible. We demonstrate how a substrate or gate voltage can control the effect of the magnetic impurities on the charge transport, and how this depends on the orientation of the magnetic impurities.
ABSTRACT
In the present study, NH4Cl-modified activated carbon was synthesized from rice husk and used as an adsorbent for removal of hinosan from underground waters. The effect of some effective parameters on the adsorption of hinosan on the rice husk NH4Cl-modified activated carbon (RHNAC) like pH, adsorbent dose, contact time, and temperature was evaluated in batch mode and the optimum conditions were determined. Kinetic of adsorption was studied by Langmuir and Freundlich's models. The equilibrium data were well fitted to the Langmuir isotherm model, and the maximum adsorption capacity of hinosan on RHNAC based on the Langmuir isotherm model was 81.366 mg g-1. The experimental adsorption data had the best fitness with the pseudo-second-order kinetic model. The applicability of the prepared adsorbent (RHNAC) was compared with other activated carbons (ZnCl2-modified activated carbon was prepared from rice husk and industrial activated carbon). The obtained results which were calculated from the selected adsorbents showed more desirability for RHNAC as an adsorbent. So, RHNAC could be introduced as an effective and cost-effective adsorbent for removal of hinosan from underground waters. Graphical abstract.
