xps analysis of model p-aramid compounds and poly(p-phenylene terephthalamide) fibers

x-ray photoelectron spectroscopy (xps) has been used to determine the surface composition of model p-aramid compounds and a number of poly(p-phenylene terephthalamide) fiber samples subjected to a variety of commercial and laboratory surface treatments. the surface compositions determined using xps are in accord with the thermodynamic res..

chemical modification of jute fibers. i. permanganate-initiated graft copolymerization methyl methacrylate onto jute fibers

a study on the graft copolymerization of methyl methacrylate onto defatted jute fibers by using potassium permanganate as initiator has been made. to determine the optimum conditions for grafting, the effects of permanganate, monomer, acid, alkali treatment, time, and temperature on percentage of grafting have been studied. kinetic studie..

rural county adopts curbside

rural lee county is located in the southeastern corner of iowa bordering missouri and illinois, has a land area of 551 square miles and a population of 43,000. in 1989, county residents and businesses will generate 36,500 tons of msw - an average of 100 tons each day in 1987, the iowa legislature passed a groundwater protection act which ..

stealth comes of age

it was not until the mid-1970s that the air force launched an ambitious program to reduce radar observability to near zero, resulting in the lockheed f-117a and northrop b-2. what made them possible were breakthroughs in the three cs: computers, composites, and coatings. computers solved the stability problem because they can automaticall..

influence of the surface treatment of graphitized carbon fibers on the curing of an amine-catalyzed epoxy-anhydride system

the surface of graphitized carbon fibers is oxidatively treated by nitric acid. fourier transform infrared attenuated total reflection spectroscopy has been utilized to monitor the influence of the surface species on the curing of an epoxy system. a curve-fitting program is used to deconvolve the overlapped infrared bands. the integrated ..

mechanical properties of glass/polypropylene multilayer laminates

multilayer laminates have been fabricated from thin sheets of glass and polypropylene with use of a special surface treatment applied to the glass surfaces, fully transcrystalline polypropylene layers could be formed. this facilitated the interpretation of the mechanical properties in terms of the microstructure of the polymeric layers. i..

effect of $gamma$ -irradiation on collagen molecules, isolated $alpha$ -chains, and crosslinked native fibers

this study shows how collagen molecules are readily damaged by $gamma$ -radiation at dosages commonly used for sterilizing biomedical products. at 1 mrad, while the reported effectiveness of the radiation at such a low dosage to completely sterilize a material is questionable, less damage was caused to the collagen peptide backbone. it is..

structure of the interface in carbon fibre composites by scanning auger microscopy

scanning auger microscopy (sam) has been used to study the fibre/matrix interface of composite materials. this novel application enables further understanding of the mechanism of failure in composites when applied to carbon fibre-reinforced epoxy material initial work was carried out on carbon fibres prior to their incorporation into the ..

studies on enzymic hydrolysis of polysaccharides in sugar beet pulp

beet fibres have been prepared from sugar beet pulp and degraded with three enzymic preparations (sp 249 from aspergillus aculeatus, driselase from irpex lacteus and onozuka from trichoderma viride) which have been characterised for their activities towards polysaccharides. the overall extent of hydrolysis was approximately 48 with onozuk..

fast responding fibre optic glucose biosensor based on an oxygen optrode

a fast responding glucose biosensor for the continuous determination of glucose is presented. the biosensor is based on an oxygen optrode, which measures the consumption of oxygen via dynamic quenching of the fluorescence of an indicator by molecular oxygen glucose oxidase (god) is immobilised onto the surface of this oxygen optrode by ad..