Phase inversion (chemistry) small pore membranes such as nanofiltration and reverse osmosis. Phase inversion (chemistry) Phase inversion is a chemical phenomenon exploited in the fabrication of artificial membranes. It is performed by removing the solvent from a liquid-polymer solution, leaving a porous, solid membrane. Phase inversion is a common method to form filtration membranes, which are typically formed using artificial polymers. The method of phase inversion is highly dependent on the type of polymer used and the solvent used to dissolve the polymer. Phase inversion can be carried out through one of four typical methods: The rate at which phase inversion occurs and
Quasi-homogeneous polynomial Quasi-homogeneous polynomial In algebra, a multivariate polynomial is quasi-homogeneous or weighted homogeneous, if there exist "r" integers formula_2, called weights of the variables, such that the sum formula_3 is the same for all nonzero terms of "f". This sum "w" is the "weight" or the "degree" of the polynomial. The term "quasi-homogeneous" comes from the fact that a polynomial "f" is quasi-homogeneous if and only if for every formula_5 in any field containing the coefficients. A polynomial formula_6 is quasi-homogeneous with weights formula_2 if and only if is a homogeneous polynomial in the formula_9. In particular, a homogeneous polynomial is