| 1. |
- Connor, M., et al.
(författare)
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Model for the consolidation of aligned thermoplastic powder impregnated composites
- 1995
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Ingår i: Journal of Thermoplastic Composite Materials. - : SAGE Publications. - 0892-7057 .- 1530-7980. ; 8:2, s. 138-162
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the role of surface energy effects, externally applied pressure, resin flow and fiber bed elasticity on the consolidation of thermoplastic-matrix composites manufactured by the powder impregnation route. Surface energy effects in the spreading of polymer droplets on fiber surfaces are discussed; then a model for the consolidation process is developed, relating the variables mentioned above. Consolidation experiments on powder-impregnated composites of the FIT type (Fibres Impregnees de Thermoplastique) were carried out using a mold attached to a servo-hydraulic testing machine. The model accurately predicts variations in void content during consolidation of carbon fiber/PEEK (CF/PEEK) and carbon fiber/PEI (CF/PEI) laminates. It was found that, at the pressures needed to achieve rapid consolidation, surface energy has a negligible influence on impregnation rate, but its effects on the void topology can be considerable. It was also shown that, when laminates of low void content are required, a minimum pressure is needed to overcome the effect of fiber bed elasticity.
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| 2. |
- Dyke, T.R., et al.
(författare)
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Experimental demonstration of data erasure for time-domain optical memories
- 1999
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Ingår i: Optical Society of America. Journal B: Optical Physics. - 0740-3224. ; 16:5, s. 805-811
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Tidskriftsartikel (refereegranskat)abstract
- Data erasure is considered an essential requirement for a practical optical time-domain memory, and it requires that the laser used have very good frequency stability. Such a laser is developed for this work, and data erasure is demonstrated with a sample of YSiO5:Eu3+ for write/rewrite pulse sequences of up to a duration of 100 μs. This is two orders of magnitude longer than had been achieved previously. Phase-sensitive detection is introduced and is shown to be invaluable for monitoring the write, rewrite, and read processes.
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