Refractive index material particles

CCT, critical cracking thickness Boltzmann constant (1.381x10 local permeability [m ] fracture resistance [N m ] average permeability in/of compact [m ] particle shape factor compact thickness [m] initial particle number concentration [m refractive index of particle material refractive index of dispersion material number density of ion i dimensionless number dimensionless number Stokes number Peclet number capillary pressure [N-m ] dynamic pressure [N m ] local liquid pressure in the compact [N-m local solid pressure in the compact [N-m ] superficial fluid velocity [m-s q gas constant [J K ] centre to centre distance [m]... 

In most of the methods discussed above, an assembly of low refractive index material is backfilled with high refractive material. Alternatively, photonic materials could be made direedy by organizing colloidal particles of high-n into 3-D arrays. These structures would not need to be annealed. Therefore, they would not suffer from the problems associated with lattice shrinkage and distortion. Unfortunately, most high refractive materials are far too dense to form well-behaved self-assemblies. The techniques described in this chapter refer to a hybrid approach where refractive material is uniformly coated on to polystyrene microspberes, prior to self-assembly. 

Flow patterns of hydrodynamic systems like the compendial dissolution apparatus may be qualitatively characterized by means of dilute dye injection (e.g., methylene blue) or by techniques using particulate materials such as aluminum powders or polystyrene particles. Flow patterns may be also visualized by taking advantage of density or pH differences within the fluid stream. The Schlieren method, for instance, is based on refraction index measurement. Hot wire anemo-metry is an appropriate method to quantitatively characterize flow rates. The flow rate is proportional to the cooling rate of a thin hot wire presented to the stream. Using laser Doppler... 

---