We demonstrate the negative refraction of microwaves in a metallic photonic crystal prism. The spectral response of the photonic crystal prism, which manifests both positive and negative refraction, is in complete agreement with band-structure calculations and numerical simulations. The validity of Snell's law with a negative refractive index is confirmed experimentally and theoretically. The n...

We developed and realized a mechanical integration concept of prism-grating-prism-assembly for the CO2M mission. The design mounts relies on kinematic mounting optical elements. Additional, ultra-light blackened covers stray light disturbance suppression are included. complete assembly was investigated by extensive thermo-mechanical simulations to verify stability under operational, launch load...

Self-consistent Polymer Reference Interaction Site Model ~PRISM! calculations and molecular dynamics ~MD! simulations were performed on athermal solutions of linear polymers. Unlike most previous treatments of polymer solutions, we explicitly included the solvent molecules. The polymers were modeled as tangent site chains and the solvent molecules were taken to be spherical sites having the sam...

Molecular dynamics simulations were performed to study the effect of the composition of the intergranular film (IGF) on anisotropic and isotropic grain growth in alpha-Al2O3. In the simulations, the IGF is formed while in contact with two differently oriented alumina crystals, with the alumina (0001) basal plane on one side and the (110) prism plane on the other. Five different compositions in ...

We present the derivation of a CTMC with levels model of diffusion in cylindrical coordinates from the partial differential equation for Fick’s law. The resulting model abstracts both molar concentration, by discrete levels, and spatial location, by discrete compartments. We apply the results to the diffusion of nitric oxide in human vessels and illustrate with simulations in the PRISM tool.

Molecular dynamics simulations of approximately 15 Å thick intergranular films (IGFs) containing SiO2 and CaO in contact with two surface terminations of the prism (101̄0) and basal planes (0001) of Si3N4 were performed using a multibody interatomic potential. Samples with the same composition (1.5 mol% CaO) and number of atoms but different crystal planes (i.e., the prism and basal planes of Si...

We present computer simulations of a simple bead-spring model for polymer melts with intramolecular barriers. By systematically tuning the strength of the barriers, we investigate their role on the glass transition. Dynamic observables are analyzed within the framework of the mode coupling theory (MCT). Critical nonergodicity parameters, critical temperatures, and dynamic exponents are obtained...

Under the effect of surface tension, a blob of liquid adopts a spherical shape when immersed in another fluid. We demonstrate experimentally that soft, centimeter-size elastic solids can exhibit a similar behavior: when immersed into a liquid, a gel having a low elastic modulus undergoes large, reversible deformations. We analyze three fundamental types of deformations of a slender elastic soli...