The pressure effects on the lattice parameters and elastic constants of the tetragonal RNi2B2C (R=Y, Lu) are investigated by means of the first principles. The predicted lattice constants and elastic constants of YNi2B2C and LuNi2B2C at 0 GPa agree well with the available data. By the elastic stability criteria under isotropic pressure, it is predicted that YNi2B2C and LuNi2B2C with tetragonal ...

We consider a variational formulation based on Maxwell’s equations for the propagation of high frequency (gigahertz to terahertz) ultrashort input pulses in dielectric materials modeled by a linear Debye medium. We demonstrate computationally the emergence of Brillouin precursors in the material (water) and the fact that the peak of this transient is attenuated at a much slower rate than is the...

The local, eigenfunction-weighted acoustic phonon density of states (DOS) tensor is calculated for a model substrate consisting of a semi-infinite isotropic elastic continuum with a stress-free surface. On the surface, the local DOS is proportional to the square of the frequency v, as for the three-dimensional Debye model, but with a constant of proportionality that is considerably enhanced com...

We test the validity of the mean-field approximation in Poisson-Nernst-Planck theory by contrasting its predictions with those of Brownian dynamics simulations in schematic cylindrical channels and in a realistic potassium channel. Equivalence of the two theories in bulk situations is demonstrated in a control study. In simple cylindrical channels, considerable differences are found between the...

The mean-square relative displacements ~MSRD! of atomic pair motions in crystals are studied as a function of pair distance and temperature using the atomic pair distribution function ~PDF!. The effects of the lattice vibrations on the PDF peak widths are modelled using both a multi-parameter Born–von Karman ~BvK! force model and a single-parameter Debye model. These results are compared to exp...

We report that a shorter Debye length and, as a consequence, decreased colloidal stability are required for the molecular interaction of folic acid-modified Au nanoparticles (Au NPs) to occur on a surface-bound receptor, human dihydrofolate reductase (hDHFR). The interaction measured using surface plasmon resonance (SPR) sensing was optimal in a phosphate buffer at pH 6 and ionic strength excee...

One hundred years after the original formulation by Petrus J.W. Debije (aka Peter Debye), the Debye Scattering Equation (DSE) is still the most accurate expression to model the diffraction pattern from nanoparticle systems. A major limitation in the original form of the DSE is that it refers to a static domain, so that including thermal disorder usually requires rescaling the equation by a Deby...

We present an embedded-atom-method (EAM) model that accurately describes the vibrational dynamics in the alkali metals Li, Na, K, Rb and Cs. The bulk dispersion curves, frequency-moment Debye temperatures and temperature-dependent entropy Debye temperatures are all in excellent agreement with experimental results. The model is also well suited for studying surface vibrational dynamics in these...

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Migration of a core-shell soft particle under the influence of an external electric field in an electrolyte solution is studied numerically. The soft particle is coated with a positively charged polyelectrolyte layer (PEL) and the rigid core is having a uniform surface charge density. The Darcy-Brinkman extended Navier-Stokes equations are solved for the motion of the ionized fluid, the non-lin...