3,818 research outputs found
Hybrid Composites Based on Polyethylene/Carbon Fibres
No full textThe mechanical properties of high-performance polyethylene (HP-PE) and carbon fibres are to some extent complimentary with respect to toughness, compressive strength and long term properties. Combining both fibres as reinforcing elements In so-called hybride composite structures can result In a unique class of structural materials in terms of strength, stiffness and impact performance. Preliminary results concerning the use of HP-PE and carbon fibres in hybride composite structures, in an epoxy matrix, will be presented emphasizing compressive and impact properties
Ultra-drawing of high-molecular-weight polyethylene cast from solution. IV Effect of annealing/re-crystallization
No full textUltra-drawing of high-molecular-weight polyethylene cast from solution. IV Effect of annealing/re-crystallization
No full text2H-NMR studies on uniaxially drawn ultrahigh molecular weight polyethylene
No full text2H-NMR expereiments were performed on deuterated, gel-drawn ultrahigh molecular weight polyethylene in order to obtain information about the orientational distribution and the molecular mobility. An increase of the spinlattice relaxation time by about an order of magnitude was observed in comparison to melt crystallized polyethylene indicating high perfection of the fibrillar crystallites. Beside the 2H-NMR resonance for a highly ordered rigid component (orthorhmobic or monoclinic fibrillar crystallites) a highly oriented mobile and a little oriented mobile component was observed. The latter can be assigned to constrained noncrystalline chain segments. saturation-spin echo pulse experiments showed a continuous transition in the T1 time of the oriented components. Variations in the line shape can be explained by a dynamic equilibrium of all-trans conormations an
Past veterinarians in South Africa
No full textAn alphabetical list containing short biographies of all deceased South African veterinarians up to 1990.[compiled by] P.J. (Bill) PosthumusVolume 1: AL -- Volume 2: M-ZAlso available in print http://137.215.9.20/record=b1893606ab2013ab201
Open brief aan den WelEdel. Gestr. Heer P.J. Joubert
No full textleyds-70-7201.pdf created from original pamphlet in the WJ Leyds Collection held in the Africana Section of the Stellenbosch University Library and Information Service.Dutch open letter to P.J. Joubert concerning a railroad concession granted to the author and two of his friends in 1885
Polymers for Electronics and Photonics: conducing ferromagnetic and nonlinear optical properties of polymers
No full text
13C-NMR study of the microstructure of ethylene-vinyl alcohol copolymers
No full textHigh—resolution NMR methods are extremely useful for microstructural
analysis of ethylene copolymers. In the present study ethylene—vinyl
alcohol (E—VOH) copolymers with an increasing content of ethylene were
synthesized and the microstructure was investigated using 13C NNR. The
methylene sequence distributions in these copolymers were investigated.
The occurence of anomalous linkages in E—VOH copolymers i.e. 1,2— and
1,4—diol structures were analyzed. The presence of 1,4—diol structures
could readily be detected in all E—VOH copolymers. The 1,2—diol structure
could be detected in E—VOH copolymers with a low content of ethylene
Raman microprobe spectra of a spin-oriented and drawn PET filament
No full textMicroprobe Raman spectra of an amorphous spin-oriented filament (1500 m/min TUS) and its room-temperature drawn derivative (D.R.=2, 5:1) are presented. Their conformational features in the glycol and carbonyl band regions are compared with DTA and x-ray diffraction data. It is apparent that the three methods of measurement record different aspects of the morphology of these filaments
- …
