Inflatable and other membrane structures are expected to become increasingly important in space exploration due to their light weight and low cost. Unlike rigid structures, these structures are typically fabricated of flexible polymers and require internal pressurization to achieve structural integrity. Due to this, inflatable structures are vulnerable to the harsh space environment and catastrophic failure from structural vibration. A MEMS-based health monitoring and control system (HMCS) for space inflatables has been developed at the University of Arkansas. Fabricated mostly from polymeric materials, the HMCS is lightweight, flexible and can be attached directly to the external surface of an inflatable to provide health monitoring. Structure-wise, the HMCS is a three-dimensional multichip module with a sensor layer at the top, a common polyimide substrate in the middle and an actuator layer at the bottom. The sensor layer consists of an interconnected network of MEMS sensors for monitoring the environmental conditions around the inflatable and also the structural vibration of the inflatable. The actuator layer, fabricated from electroactive polymers, provides a two-dimensional shape control capability to the HMCS. When operated with strain and vibration sensors in the sensor layer, the polymer actuator can deform the surface contour of the inflatable to remove 'wrinkles' and dampen structural vibration.

No abstract

This report describes the basic parameters which directly influence the behavior of a coal slurry pipeline transportation system and determine the limitations of the system performance. The purpose of this technology assessment is to provide an identification and understanding of the critical factors which must be given consideration in the design and evaluation of such a s~urry haulage system intended for use in an underground coal mine. The slurry haulage system will be utilized to satisfy the transportation requirements of conveying, in a pipeline, the coal mined by a continuous mining machine to a storage location near the mine entrance or to a coal preparation plant located on the surface.

No abstract