Inertia effects in rheometrical flow systems Part 2: The balance rheometer

The flow field of a linear viscoelastic fluid in the balance rheometer, taking fluid inertia into account, has been studied theoretically and an exact solution is given. The flow field of a Newtonian fluid is included in this solution as a special case. The forces and couples on the hemispheres are readily deduced from this solution

Inertia effects in rheometrical flow systems

The flow field of a linear viscoelastic material in the orthogonal rheometer, taking fluid inertia into account, has been studied theoretically and an exact solution is given. The flow field of a Newtonian liquid is included in this solution as a special case. The forces on the plates are readily deduced from this solution. The paper concludes with an energy consideration

Identifying logarithmic tracts

We show that a direct tract bounded by a simple curve is a logarithmic tract and further give sufficient conditions for a direct tract to contain logarithmic tracts. As an application of these results, an example of a function with infinitely many direct singularities, but no logarithmic singularity over any finite value, is shown to be in the Eremenko-Lyubich class.Comment: 12 page

Community Engagement as a Student-Athlete

Hannah Waterman discusses student engagement at Linfield College with regard to her involvement with the volleyball team.https://digitalcommons.linfield.edu/inauguration2019_students/1020/thumbnail.jp

Inertia effects in rheometrical flow systems Part 3: Some energy considerations with respect to the flow field in the balance rheometer

Following up a previous paper by one of the presents authors on the flow field in the balance rheometer, inertia effects being included, in this paper some energy considerations with respect to this flow field are presented. It is shown that in a frame rotating with the same angular velocity as the hemispheres the power supplied by these hemispheres equals the rate of energy dissipation in the sample, i.e. in this coordinate system there is no “stress power paradox”. Further it is shown that the “elastic” couple for a Newtonian liquid, appearing in the calculations, stems from the extra kinetic energy caused by the deviation of the actual flow field from the flow field that appears when inertia effects are ignored

Place, space and the reinvention of social emancipation on a global scale : second thoughts on the Third World Social Forum

empowerment;trade unions;internationalism;social movements