Critical Appraisal of Diffusivity Determinations from Experimental Creep Data

1988 ◽  
Vol 71 (5) ◽  
pp. C-241-C-243 ◽  
Author(s):  
Atul-H. Chokshi
Keyword(s):  
Critical Appraisal ◽  
Creep Data ◽  
Experimental Creep

Tunable Membrane for Electromagnetic Devices Using Dielectric Elastomers

2008 ◽  
Vol 61 ◽  
pp. 141-146
Author(s):  
Christian Bolzmacher ◽  
Karin Bauer ◽  
Ulrich Schmid ◽  
Helmut Seidel ◽  
Moustapha Hafez
Keyword(s):  
Material Model ◽  
Silicone Membrane ◽  
Creep Data ◽  
Electromagnetic Actuators ◽  
Membrane Behavior ◽  
Electromagnetic Devices ◽  
Dynamic Experiments ◽  
Experimental Creep ◽  
Strain Relationship ◽  
Tunable Stiffness

The amplitudes of miniaturized electromagnetic actuators are clearly enhanced if the eigenfrequencies of the membrane are used for actuation. However, the bandwidth for such operation is very limited. This can be overcome to some extent by the employment of membranes with electrically tunable stiffness. In this context we investigated membranes of dielectric elastomer materials and present experimental results on the ability to change their pre-strain to shift the eigenmodes to lower frequencies upon activation. Furthermore, the viscoelastic properties of an acrylic and a silicone membrane are investigated and compared to dynamic experiments. The parameters for the stiffness and viscoelasticity are derived from the experimental creep data and incorporated in a hyperelastic material model. Using this adapted stress-strain relationship the membrane behavior over time can be evaluated for different loading as well as pre-strain conditions.

935: Critical Appraisal of the Role of Ureteroscopy in Treatment of Pediatric Renal and Ureteric Calculi

2007 ◽  
Vol 177 (4S) ◽  
pp. 310-310
Author(s):  
Sumit Dave ◽  
Luis H. Braga ◽  
Antoine E. Khoury ◽  
Walid A. Farhat
Keyword(s):  
Critical Appraisal ◽  
Ureteric Calculi

Ownership without Legitimacy?

2008 ◽  
pp. 85-105 ◽  
Author(s):  
R. Kapeliushnikov
Keyword(s):  
Economic Growth ◽  
Critical Appraisal ◽  
Birth Trauma ◽  
Fair Play ◽  
Different Types

The paper examines the problem of legitimation of the privatization’s outcomes in Russia and provides a critical appraisal of various political proposals for its resolution. The analysis proceeds from a distinction between two different types of ownership illegitimacy: "definite" and "vague" ones. The paper argues that the "vague" illegitimacy that has evolved in Russia is not an absolute obstacle for economic growth but rather an institutional birth trauma which is common for all post-socialist countries and which could be cured only by piecemeal approaching of relationships between "strong" and "weak" economic actors to principles of fair play.

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