highly enantioselective hydrolysis of (r,s)-phenylalanine isopropyl ester by subtilisin carlsberg. continuous synthesis of (s) -phenylalanine in a hollow fiber/liquid membrane reactor

the resolution of racemic phenylalanine esters with esterases has been reexamined in relation to the development of a continuous process based on the use of hollow fiber supported liquid membrane (slm) reactors. the requirement for high enantioselectivity was met by phenylalanine isopropyl ester, whose (r)-enantiomer was found refractory ..

effect of pbo on some properties, especially light scattering, of glasses with mixed alkalis

the starting point of this study was to find connections between light scattering and the chemical composition of the glasses with mixed alkalis. by means of a comparison of the results of different papers it was possible to draw some interesting conclusions. chiefly pbo increases the light scattering of fibres, but it prevents the influe..

optimization of the inp/sio//2 interface treatment by (nh//4) //2s//x for the inp misfet fabrication technology

in this paper, the inp surface sulfidation by (nh//4)//2s or (nh//4)//2s//x solutions is investigated in order to reduce the long-term drain-current-drift of misfet devices and the interface state density at the inp/sio//2 interface. in order to ensure good reproducibility of this treatment, a full chemical characterization of the ammoniu..

scanning probe microscopy of carbon fiber surfaces

in order to gain a better understanding of the role that the carbon fiber surface plays in adhesion, it is necessary to be able to observe it at atomic dimensions. two scanning probe microscopes have been found to be particularly useful for this task. both the scanning tunneling microscope (stm) and the atomic force microscope (afm) use p..

chemically amplified negative resist system using acid-catalyzed etherification of carbinol

an acid-catalyzed etherification of carbinol has been used in the design of an alkali developable, highly sensitive negative resist. the resist consists of diphenylcarbinol (dpc), an acid generator, and a novolak resin shows the best lithographic performances in terms of the resist sensitivity and resolution among the resist using carbino..

reproducible electrodeposition of biomolecules for the fabrication of miniature electroenzymatic biosensors

a technique has been developed for reproducibly depositing an enzyme or other biomolecule onto the surface of a conductor specifically, glucose oxidase has been electrodeposited onto the surface of an electrode previously electroplated with platinum black this deposition takes place without the assistance of an electropolymerizable matrix..

fiber optic biosensing based on molecular recognition

a review is given on the use of specific biorecognition elements (such as enzymes or optically active receptors) in optical sensing of chemical species. in enzyme-based sensors various options exist; depending on which species is immobilized, assays for substrates (such as glucose, lactate or cholesterol), enzymes (such as carboxylesteras..

on the influence of additions of phthalocyanine metal complexes on the low temperature pyrolysis of cellulose hydrate

a study was made of the initial stage of pyrolysis of the cellulose hydrate fiber in the presence of cobalt and copper phthalocyanine additives. the temperature of the onset of degradation is lower in the presence of an additive, and the process of degradation of the cellulose elementary unit is initiated. it proceeds with the formation o..

characterization of interfacial bond strength by dynamic analysis

short beam shear, double cantilever beam, and torsional dynamic mechanical (dma) tests were performed on composite materials systems to characterize the interfacial bond strength. the composite materials were unidirectional flat laminate with different fiber surface treatments and sizings. the results indicated that the dma test was super..

hydrolysis of butteroil by immobilized lipase using a hollow-fiber reactor. part iii. multiresponse kinetic studies

a lipase from aspergillus niger immobilized by adsorption on microporous, polypropylene hollow fibers was used to effect the continuous hydrolysis of the glycerides of butter-oil at 40 $degree$ c and ph 7.0. the effluent concentrations of 10 different free fatty acid products were measured by high-performance liquid chromatography (hplc)...