study on modified phenolic resin. iii. modification with p-hydroxyphenylmaleimide/acrylic ester copolymer

the improvement of toughness and heat resistance of phenolic resin was examined by blend of novolac and copolymers prepared from p-hydroxyphenylmaleimide (hpmi) and acrylic ester. copolymers of hpmi and acrylic esters, such as methyl acrylate, ethylacrylate, n-butylacrylate, or 2-ethylhexyl acrylate, were synthesized. average molecular we..

fiber-matrix adhesion and its effect on composite mechanical properties. iii. longitudinal (0 $degree$ ) compressive properties of graphite/epoxy composites

an experimental investigation was performed to quantify the relationship between fiber-matrix adhesion as determined by single fiber interfacial shear strength tests with the compressive properties and failure modes of unidirectional graphite/epoxy composites. the compression tests were conducted on three identical sets of composites diff..

micromechanics prediction of the shear strength of carbon fiber/epoxy matrix composites. the influence of the matrix and interface strengths

presently there is great interest in understanding and improving the bonding between the fibers and matrix in high performance composite materials. indeed, the fiber-matrix adhesion in many recently-developed systems is poor. to improve bonding, various fiber surface treatments have been developed. these treatments are often evaluated by ..

compact ecr-source of ions and radicals for semiconductor surface treatment

a compact microwave ecr-source of ions and free radicals has been fabricated. it includes a stainless steel tube, ceramic microwave input and permanent smco//5 ring-shaped magnets. its working pressure range is 10** $minus$ **4-10** $minus$ **2 torr using ar, h//2, n//2 and some other gases. the maximum ion current density in a hydrogen d..

effect of fabrication, sterilization and mediators-blood compatability of polyurethanes

the possible changes in the surface and physical properties of polyether urethane urea (peuu) implants, including their interaction with blood, due to the different preparation methods, sterilization techniques and long term storage in different environmental conditions have been investigated by conducting the studies of mechanical proper..

hydrogen fluoride vapor etching for pre-epi silicon surface preparation

hydrogen fluoride vapor etching of silicon dioxide was studied for its applicability to the preparation of silicon surfaces for low temperature epitaxy. the etching behavior of hydrogen fluoride vapor with and without added water vapor was studied qualitatively by observing changes in hydrophobicity, and quantitatively using ellipsometry...

growth of passivating uv/ozone oxides on inp. correlations between chemical composition and interfacial electrical properties

native oxides grown on inp by uv/ozone oxidation are studied as a function of various experimental conditions. they are compared to standard inpo//4 thermal oxides and to in(po//3)//3 anodic oxides the chemical composition of these oxides is investigated by x-ray photoelectron spectroscopy. the atomic composition of the uv oxides varies f..

hydrolysis of butteroil by immobilized lipase using a hollow-fiber reactor. part i. lipase adsorption studies

adsorption of proteins from a crude preparation containing a lipase from aspergilius niger on microporous polypropylene hollow fibers was studied at six different temperatures. langmuir isotherms accurately describe the overall adsorption equilibria. lipase is selectively adsorbed relative to the other proteins in the crude preparation. h..

hydrolysis of butteroil by immobilized lipase using a hollow-fiber reactor. iv. effects of temperature

a lipase from aspergillus niger, immobilized by adsorption on microporous polypropylene hollow fibers, was used to effect the hydrolysis of the glycerides of melted butterfat at ph 7.0 at 40, 50, 55, and 60 $degree$ c. mcllvane buffer was pumped upward through the lumen, and melted butterfat was pumped upward through the shell side of a h..

fluorescence-based fiber optic biosensor for the flow-injection analysis of penicillin

a penicillin fiber optic sensor is described. the sensor is based on co-immobilization of a ph indicator, fluorescein isothiocyanate (fitc), and penicillinase on a preactivated biodyne b membrane attached to the end of a bifurcated optical fiber. the characteristics of the sensor are investigated in conjunction with a flow injection analy..