60,988 research outputs found
Hall current effects in dynamic magnetic reconnection solutions
The impact of Hall current contributions on flow driven planar magnetic merging solutions is discussed. The Hall current is important if the dimensionless Hall parameter (or normalized ion skin depth) satisfies cH>η where η is the inverse Lundquist number for the plasma. A dynamic analysis of the problem shows, however, that the Hall current initially manifests itself, not by modifying the planar reconnection field, but by inducing a non-reconnecting perpendicular "separator" component in the magnetic field. Only if the stronger condition c2/H > η is satisfied can Hall currents be expected to affect the planar merging. These analytic predictions are then tested by performing a series of numerical experiments in periodic geometry, using the full system of planar magnetohydrodynamic (MHD) equations. The numerical results confirm that the nature of the merging changes dramatically when the Hall coupling satisfies c2/H > η. In line with the analytic treatment of sheared reconnection, the coupling provided by the Hall term leads to the emergence of multiple current layers that can enhance the global Ohmic dissipation at the expense of the reconnection rate. However, the details of the dissipation depend critically on the symmetries of the simulation, and when the merging is "head-on" (i.e., comprises fourfold symmetry) the reconnection rate can be enhanced
Broadening \u3cem\u3eJournal of Public Policy & Marketing\u3c/em\u3e’s Outreach: My Tour of Duty” as Editor
The article offers the insights of Journal of Public Policy & Marketing\u27s former editor on his tenure, objectives, and initiatives. He states that on editor tenure, he observed that a crucial time in a journal\u27s life is the handoff or transition between retiring and incoming editors. He says that the aim in his term was to provide information regarding public policy issues\u27s impact on marketing behaviors. He adds that he promoted ethnography topics during his tenure
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