5 research outputs found
Multi-Functional Carbon Fibre Composites using Carbon Nanotubes as an Alternative to Polymer Sizing
Carbon fibre reinforced polymers (CFRP) were introduced to the aerospace, automobile and civil engineering industries for their high strength and low weight. A key feature of CFRP is the polymer sizing - a coating applied to the surface of the carbon fibres to assist handling, improve the interfacial adhesion between fibre and polymer matrix and allow this matrix to wet-out the carbon fibres. In this paper, we introduce an alternative material to the polymer sizing, namely carbon nanotubes (CNTs) on the carbon fibres, which in addition imparts electrical and thermal functionality. High quality CNTs are grown at a high density as a result of a 35 nm aluminium interlayer which has previously been shown to minimise diffusion of the catalyst in the carbon fibre substrate. A CNT modified-CFRP show 300%, 450% and 230% improvements in the electrical conductivity on the ‘surface’, ‘through-thickness’ and ‘volume’ directions, respectively. Furthermore, through-thickness thermal conductivity calculations reveal a 107% increase. These improvements suggest the potential of a direct replacement for lightning strike solutions and to enhance the efficiency of current de-icing solutions employed in the aerospace industry
Experimental Evidence for Simple Relations between Unpolarized and Polarized Parton Distributions
The Pauli exclusion principle is advocated for constructing the proton and
neutron deep inelastic structure functions in terms of Fermi-Dirac
distributions that we parametrize with very few parameters. It allows a fair
description of the recent NMC data on and at
, as well as the CCFR neutrino data at and . We
also make some reasonable and simple assumptions to relate unpolarized and
polarized quark parton distributions and we obtain, with no additional free
parameters, the spin dependent structure functions and
. Using the correct evolution, we have checked that they
are in excellent agreement with the very recent SMC proton data at and the SLAC neutron data at .Comment: 17 pages,CPT-94/P.3032,latex,6 fig available on cpt.univ-mrs.fr
directory pub/preprints/94/fundamental-interactions /94-P.303
Fermi-Dirac Distributions for Quark Partons
We propose to use Fermi-Dirac distributions for quark and antiquark partons.
It allows a fair description of the -dependence of the very recent NMC data
on the proton and neutron structure functions and at
GeV, as well as the CCFR antiquark distribution .
We show that one can also use a corresponding Bose-Einstein expression to
describe consistently the gluon distribution. The Pauli exclusion principle,
which has been identified to explain the flavor asymmetry of the light-quark
sea of the proton, is advocated to guide us for making a simple construction of
the polarized parton distributions. We predict the spin dependent structure
functions and in good agreement with EMC and SLAC data.
The quark distributions involve some parameters whose values support well the
hypothesis that the violation of the quark parton model sum rules is a
consequence of the Pauli principle.Comment: 12 pages,CPT-93/P.2961,latex,6 fig available on cpt.univ-mrs.fr
directory pub/preprints/93/fundamental-interactions/93-P.296