100 Years of Powder XRD

Phase Characterization of TiO2 Powder by XRD and TEM

In this study, the commercial TiO2 nanopowder and micropowder of anatase phase and rutile phase have been characterized by x-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD patterns of nano-TiO2 in rutile and anatase phases exhibit broad peaks whereas both phases of micro-TiO2 demonstrate very sharp peaks. TEM images show that the grain size of TiO2 micropowders and TiO2 n...

MgSO4•11H2O – POWDER XRD, RAMAN AND VIS-NIR SPECTROSCOPIC CHARACTERIZATION

Why MgSO4·11H2O? Hydrous Mg-sulfate with 11 structural waters (11w hydrate), a new low temperature hydrated Mg-sulfate phase, was first reported in 2006 by Peterson & Wang [1]. They did a structural refinement using single-crystal XRD and suggested that the crystal molds in outcrops at Meridiani [2] could indicate melting and loss of the 11w hydrate. Chou et al. [3] proposed a phase boundary be...

100 years of servitude.

Physics in 100 years

Here I indulge in wide-ranging speculations on the shape of physics, and technology closely related to physics, over the next one hundred years. Themes include the many faces of unification, the re-imagining of quantum theory, and new forms of engineering on small, intermediate, and large scales. When Leon Cooper, on behalf of Brown University, asked me to contribute to their 250th anniversary ...

100 years of sperm chemotaxis

Exactly 100 years ago, F.R. Lillie reported chemotaxis in animal sperm for the first time (Lillie, 1912). Chemo-taxis refers to the directed movement of a cell or organism to the source of a chemical gradient; the chemical agent that elicits this movement is called a chemoattrac-tant. Chemotaxis had previously been shown by Pfeffer (1884) for fern spermatozoids; however, attempts to demonstrate...