membranes for chemical sensors

recent trends in the development of membranes for silicon-based chemical sensors are reviewed. the sensitization of the gate dielectric of ph isfets has been chosen as an illustrative working example and recent results are analysed in the three main identified directions of research: deposition and grafting of sensitive membranes; ion imp..

applied dielectric spectroscopy of polymeric composites

in this article a theoretical background for understanding dielectric phenomena in heterogeneous polymeric composites is presented, and the application of these principles to practical problems is illustrated by experimental examples. first a short overview of the existing theoretical mixing formulae is given, the differences in these app..

fem analysis on frp cutting

a finite element model of machining of frp has been developed for a better understanding of the microscopic machining mechanism such as deformation and fracture of both fiber (e glass) and matrix(polyester). the influence of the fiber direction angle and tool rake angle upon the mechanism is analyzed. the criteria of the maximum tensile s..

new method for fabricating langmuir-blodgett films of water-soluble proteins with retained enzyme activity

a new method has been developed for fabricating monolayers of water-soluble proteins on a water surface and transferring the protein langmuir-blodgett (lb) films from the water surface monolayers of glucose oxidase (god) or cytochrome c(cyt-c) spread on 3 m (nh//4)//2so//4 solution were transferred onto the water surface with a fromherz l..

characterization of biomass pyrolysis tars produced in the relative absence of extraparticle secondary reactions

product distributions from the atmospheric pressure pyrolysis of sugar-cane bagasse and silver birch were determined in a wire-mesh reactor as a function of temperature (300-900 $degree$ c) and heating rate (1-1000 k s** $minus$ **1), over a range of holding times between 0 and 100 s. major groups of components present in the tars were id..

initiation of mineralization in bioprosthetic heart valves: studies of alkaline phosphatase activity and its inhibition by alcl//3 or fecl//3 preincubations

the principal cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde-pretreated porcine aortic valves is calcification. other prostheses composed of tissue-derived and polymeric biomaterials also are complicated by deposition of mineral. in this study the authors focused on the relationship of ap to ear..

comparison between edm wire-cut and laser cutting of carbon fibre composite materials

a comparative study has been made between edm wire-cut and laser cutting process on the material removal rate, the quality of the cut edge and the resulting material damage in a carbon fibre composite material. in general, edm wire-cut produces better surface finish and edge quality, smaller heat-affected zone and better control of proces..

polygalacturonate lyase production by thermomonospora curvata on protein-extracted lucerne fiber

protein-extracted lucerne fiber was used as carbon and energy source for production of extracellular polygalacturonate lyase by thermomonospora curvata. the optimal fiber concentration was 1.5 (w/v); peak lyase activity in culture fluid occurred after 3 days growth at 53 $degree$ c. during that time, lyase biosynthesis was controlled thro..

second generation biosensors

enzyme-membrane electrodes using glucose oxidase in combination with peroxide detection dominate in the field of laboratory analyzers for diluted samples. using the same indication principle, extremely fast responding glucose sensors have been fabricated by covering thin film metal electrodes with a porous enzyme layer. in the second gene..

effects of surface treatments of fibers on the interfacial properties in single-fiber composites. part i. single carbon fiber/epoxy resin composite system

the interfacial properties between fibers and the matrix contribute to the overall properties in high performance composites plasma treatments (ar, o//2, cf//4/o//2, n//2/h//2) have been performed on carbon fibers to improve the fiber-matrix interaction the treatment efficiency was checked by the single-fiber technique, while the surface ..