modes of deformation and failure of kevlar 49 fibers and composites

fracture-topography and stress-optical-microscopy are utilized to study the deformation and failure modes of kevlar 49 fibers and their epoxy composites. fracture topographies of bare yarns, composite strands, and pressure vessels reveal kevlar 49 fibers fail in tension by axially splitting 20 to 50 times their diameter d (20 to 50d) alon..

chemical treatment of silicate glasses for producing anti-reflection surfaces

a brief description is given of chemical treatments to reduce fresnel reflectance of bk7 and sio sub 2 for high fluence laser applications in the spectral range 0.25 to 1.06 mu . (era citation 09:012392)

adhesion of graphite fibers to epoxy matrices: i. the role of fiber surface treatment, reprint: adhesion of graphite fibers to epoxy matrices: i. the role of fiber surface treatment

no abstract available

moisture-transmitting polymers: the vapor transmissivity and physical properties of hydrophilic polyurethane films qualify them for a variety of applications. ntis tech note

this citation summarizes a one-page announcement of technology available for utilization. a document describes a study of hydrophilic polyurethanes. hydrophilic polymers are attractive materials for fabric coatings with high-moisture vapor transmission for use in reverse osmosis, biomedical applications, separation processes, and the like..

thin film battery/fuel cell power generating system. sixth quarterly report, july-september 1977

the purpose of this research program is the demonstration of the technical feasibility of a high-temperature, solid-electrolyte fuel cell, building on the presently-existing technological base. the bulk of the work consists of identifying and selecting candidate component materials, fabricating cells and cell stacks from these materials, ..

thin film battery/fuel cell power generating system. seventh quarter report, october 1977-december 1977

the purpose of this research program is the demonstration of the technical feasibility of a high-temperature, solid-electrolyte fuel cell, building on the presently-existing technological base. the bulk of the work consists of identifying and selecting candidate component materials, fabricating cells and cell stacks from these materials, ..

dislocations in syton polished inp. rept. for aug 81-aug 82

this report is about the effect of syton polishing on single crystal wafers of inp. whether the material is intended for device fabrication by ion implantation methods or as a substrate for epitaxial growth, it is important that the surface be smooth and clean, and that the region of the material near the surface be free of dislocations. ..

corrosion resistant magnesium-based materials for naval applications. technical review rept

this report reviews the corrosion related properties of magnesium, magnesium alloys, and magnesium based composites. it attempts to place in perspective the corrosion behavior/limitations of these materials in environments likely to experienced by naval systems these are treated from both macro- and microscopic perspectives. the role of b..

submarine hull insulation materials system. final rept. dec 84-mar 85 on phase 2

the development, fabrication, and testing of a complete submarine hull insulation materials system, based upon an anti-sweat fiberglass insulation panel is described. recommendations for further work are outlined. in the product submitted, one-inch-thick felts of three pounds per cubic foot density, made from five-micron diameter glass fi..

effect of carbon fibre surface treatment on moisture absorption and interlaminar shear strength of carbon fibre/epoxy resin composites technical rept

carbon fibres surface treated to eight different levels of the standard treatment were moulded into unidirectional composites in an epoxy resin. the composites were immersed in boiling water or exposed to a hot humid environment (70c, 95 rh), and the water absorption, swelling and interlaminar shear strength were measured. the reversibili..