Water-in-oil mixtures were grouped into four states or classes: stable, mesostable, unstable, and entrained water. Of these, only stable and mesostable states can be characterized as emulsions. These states were established according to lifetime, visual appearance, complex modulus, and differences in viscosity. Water content at formation was not an important factor. Water-in-oil emulsions made ...

the purpose of this study was to map the structure of scientific outputs of petroleum field in science citation index (sci) accessible via web of science (wos) during 1990 to 2011 and determine the position of iran. the used research methods were citation analysis and historiography. the results showed that there were totally 26859 records indexed in the petroleum discipline during 1990-2011 in...