Abstract Given a flow domain D with subdomains D1 and D2, piecewise potential vorticity inversion (PPVI) inverts (PV) anomaly in D2 assumes vanishing PV where boundary conditions must be taken into account. It is widely held view that the exerts far-field influence on D1, which revealed by PPVI. Tests of this assertion are conducted using simple quasigeostrophic model an upper layer contains un...

Various properties of open strings in external constant E.M. fields are reviewed. In particular, the charged-particle pair production rate in an external electric field is evaluated, and shown to reduce to Schwinger’s formula in the limit of low-intensity fields. Open strings in external magnetic fields are shown to undergo an infinite number of phase transitions as the strenght of the field in...