Gallium nitride (GaN) nanocrystalline powder has been prepared by sol–gel method. The GaN powder has been confirmed as single-crystalline GaN with wurtzite structure by X-ray diffraction (XRD) and selected-area electron diffraction (SAED), and the diameter of the grains of GaN powder changes...

Analysts of survey data are often interested in modelling the population process, or superpopulation, that gave rise to a `target' set of survey variables. An important tool for this is maximum likelihood estimation. A survey is said to provide limited information for such inference if data used...