les composites a matrice metallique a fibres longues (metal matrix composite with long fibers)

the reinforcement of metal matrices by long ceramic fibers such as alumina, carbon, silicium carbide, leads to very high specific characteristics such as stiffness and strength at both room and high temperature. progress achieved in the development of new fibers performance has revived the interest for metal matrix composites (mmc) develo..

diamond tool wear of electrodeposited nickel-phosphorus alloy

nickel-phosphorus alloys are attractive materials for diamond turning applications such as fabrication of large optics and other high precision parts. although the mechanism is not understood, diamond tool wear is minimized when the phosphorus content of the deposit is greater than 11 (wgt). in recent years, increased attention has been d..

duplex nickel step test standards. final rept.reprint: duplex nickel step test standards

standards for measuring potential difference and thickness between multilayer nickel coatings have been developed. the paper describes the techniques used to fabricate and certify these standards and the effect of various operating parameters on the accuracy of both thickness and potential measurements. this standard reference material is..

bhabha atomic research centre: annual report 1988. progress rept

the research and development (r and d) work carried out in the bhabha atomic research centre (barc), bombay during 1988 is summarised and presented in the sections entitled physical sciences, chemical sciences, materials and materials science, radioisotopes, reactors, fuel cycle, radiological safety and protection, electronics and instrum..

development of a small gantry robotic workcell for deoxyribonucleic acid (dna) filter array construction

at los alamos national laboratory, we have constructed a primary cosmid library of human chromosome 16. this library consists of an 11-fold representation of the chromosome and is arrayed in microtiter plate format. a need has arisen in the large scale physical mapping of this chromosome, to array spots of dna from each of these colonies ..

development of a rapid immunoassay for syphilis. final rept sep-dec 87.reprint: development of a rapid immunoassay for syphilis

a simple, easy and quick eia for antibody to treponema pallidum (tp) was developed. it is tentatively called dd-eia (dot diffusion enzyme immunoassay). the center of glass fiber (quartz preferred) filter paper is marked as a tiny dot with a pencil. 25 to 50 ul (depending on antigen concentration) of antigen solution is placed on the mark ..

bibliographie technique des fibres de polyethylene hautes performances (technical bibliography of high performance polyethylene fibers)

polyethylene fibers are applied in several industrial manufacturing fields. the fabrication techniques and the characteristics of the fibers are summarized. the different surface finishing and properties obtained are underlined. the mechanical, electrical, chemical and thermal properties are reported. the effects of light and the thermal ..

mechanism of electrochemical and anisotropic silicon etching and its applications

anisotropic silicon etching is a key technology for the fabrication of micromechanical devices. it allows for the precise three-dimensional structuring of miniature sensors and actuators in an ic compatible way. the three main properties that make this technique so widely applicable are the dependence of the etch rate on the crystal direc..

polymerized asphalt emulsion. final rept

it has been claimed that polymerized asphalt emulsion has outstanding characteristics of elasticity, adhesion, and cohesion which allows its use in seal coats in high speed, high volume roads, such as interstate highways. another use would be on a lower classification road with sharp turns which prevent the use or greatly shortens the lif..

experiment k-6-21. effect of microgravity on (1) metabolic enzymes of type 1 and type 2 muscle fibers and on (2) metabolic enzymes, neutransmitter amino acids, and neurotransmitter associated enzymes in motor and somatosensory cerebral cortex. part 1: met

the individual fibers of any individual muscle vary greatly in enzyme composition, a fact which is obscured when enzyme levels of a whole muscle are measured. the purpose of this study was therefore to assess the changes due to weightless on the enzyme patterns composed by the individual fibers within the flight muscles. in spite of the l..