(Received: May 4, 2010; June 10, 2010) Abstract: Textile cardiovascular prostheses are woven or knitted structures made generally from biocompatible polyester fibres. After production, they have to undergo special treatments before packaging such as compaction. This treatment is necessary to reduce porosity especially for knitted structures, but it can modify poly(ethylene terephthalate) (PET) ...

Given a two dimensional, non-overlapping layout of convex and non-convex polygons, compaction can be thought of as simulating the motion of the polygons as a result of applied \forces." We apply compaction to improve the material utilization of an already tightly packed layout. Compaction can be modeled as a motion of the polygons that reduces the value of some functional on their positions. Op...

The Texas Department of Transportation (TxDOT) employs the impact hammer method of sample compaction for laboratory preparation of road base and subgrade materials for testing. Experience has shown that this method may not adequately represent the true field performance of the materials. This report describes results investigating how different lab compaction methods influence the laboratory ch...

Issue: The moisture content of a fill material will affect its compaction characteristics and needs to be evaluated during quality control of the fill operation. When the fill is drier than its optimum moisture content, any moisture in the fill serves as a lubricant and helps the relative movement of the particles when densifying under vibratory compaction. When the fill is wetter than its opti...

Real-time monitoring during soil compaction can be made possible by utilizing the vibration signature of a vibratory roller compactor. The compactor and soil constitute a coupled dynamic system, albeit complex and nonlinear. As the soil density increases and its mechanical properties change, the dynamic response of the compactor will change. Developing a thorough knowledge of the relationship b...

This paper proposes a new automatic speech summarization method having two stages: important sentence extraction and sentence compaction. Relatively important sentences are extracted from the results of large-vocabulary continuous speech recognition (LVCSR) based on the amount of information and the confidence measures of constituent words. The set of extracted sentences is compressed by our se...

The role of microtubules during compaction of the 8-cell-stage mouse embryo was investigated using the drugs Taxol (which leads to a non-controlled polymerization of tubulin) and Nocodazole (which causes depolymerization of microtubules). Taxol inhibits compaction in most non-compacted embryos and reverses it in already compacted embryos. These effects were observed on both cell flattening (as ...

Cell competition is a quality control mechanism that eliminates unfit cells. How cells compete is poorly understood, but it is generally accepted that molecular exchange between cells signals elimination of unfit cells. Here we report an orthogonal mechanism of cell competition, whereby cells compete through mechanical insults. We show that MDCK cells silenced for the polarity gene scribble (sc...

We present a general mathematical theory for the mechanical interplay in tissue-equivalents (cell-populated collagen gels): Cell traction leads to compaction of the fibrillar collagen network, which for certain conditions such as a mechanical constraint or inhomogeneous cell distribution, can result in inhomogeneous compaction and consequently fibril alignment, leading to cell contact guidance,...

Operating systems for sensor networks must provide energy and memory-space efficient execution environments for applications because of the resource constraints of the sensor nodes. The shared-stack cooperative threads have been proposed to conserve stack memory-space and to minimize the possibility of stack overflow in the sensor operating systems. However, stack switching brings about externa...