a new dynamic friction model for modeling of elliptical vibration assisted turning (evat) was developed in this research. the periodic change of the friction force direction is known to be one of the most important causes of this phenomenon. in modeling of machining processes (including the evat process), static coulomb friction model was employed by most of the researchers. because of the peri...

Using the "simplest cubic fields" of D. Shanks, we give a modified proof and an extension of a result of Uchida, showing how to obtain cyclic cubic fields with class number divisible by n, for any n. Using 2-descents on elliptic curves, we obtain precise information on the 2-Sylow subgroups of the class groups of these fields. A theorem of H. Heilbronn associates a set of quartic fields to the ...