Showing papers by "University of Twente published in 1984"
TL;DR: In this article, a solution-diffusion model for the permeation of liquid mixtures through polymeric membranes taking into account coupling of fluxes has been developed, and the model is applied to the separation by pervaporation of ethanol-water mixture through cellulose acetate.
288 citations
TL;DR: It is concluded that in the ultrafiltration of medium molecular weight solutes (10,000 to 100,000 daltons) osmotic pressure limitation is more likely than gel layer limitation.
233 citations
TL;DR: In this paper, a self-regulating insulin delivery system based on the competitive binding of glucose and glycosylated insulin to the lectin Concanavalin A is proposed.
96 citations
01 May 1984
TL;DR: In this paper, the isotherms of human serum albumin, human immunoglobulin G (HIgG), and human fibrinogen (HFb) onto polystyrene (PS)-latex were determined by depletion of protein in the solution, which was either followed by radioactivity measurements or by UV spectroscopy.
Abstract: Isotherms of human serum albumin (HSA), human immunoglobulin G (HIgG), and human fibrinogen (HFb) onto a polystyrene (PS)-latex were determined by depletion of protein in the solution, which was either followed by radioactivity measurements or by UV spectroscopy. Different adsorption isotherms for the same protein were obtained when either radioactivity measurements or UV spectroscopy was used as a detection technique. In order to obtain reliable results from competitive protein adsorption experiments, a method based on the use of high-performance liquid chromatography was developed. A strong preferential adsorption of HFb was observed when adsorption studies were carried out with mixtures of HSA, HFb, and HIgG. When adsorption studies were carried out with solutions containing HSA monomer and dimer, a strong preferential adsorption of HSA dimer was also observed.
68 citations
51 citations
TL;DR: AISI 304, 314, 321, and Incoloy 800H have been subjected to several pretreatments: polishing, milling, grinding, and cold drawing as discussed by the authors.
Abstract: AISI 304, 314, 321, and Incoloy 800H have been subjected to several pretreatments: polishing, milling, grinding, and cold drawing. In the temperature range 800–1400 K, cold work improves the oxidation resistance of AISI 304 and 321 slightly, but has a relatively small negative effect on the oxidation resistance of AISI 314 and Incoloy 800H. Milling results in an enlargement of the surface area with a factor 2.5.
23 citations
TL;DR: High- and low-affinity fractions greatly differed not only with respect to their APTT activity, but also where their complement-inhibitory activities were concerned, and could not be explained by the observed differences in molecular weight of high and low affinity heparin respectively.
20 citations
TL;DR: In this paper, the authors describe the mathematical model of the diffusion of polymers in the course of the formation of a membrane, and describe the procedure of precipitation and immersion in a polymer solution coulee.
Abstract: Description mathematique de la diffusion au cours de la formation d'une membrane par le procede de precipitation par immersion dans lequel une solution coulee d'un polymere dans un solvant est immergee dans un bain non solvant
19 citations
TL;DR: In this paper, the titration curves of complicated redox systems were calculated using the fast calculation procedure described earlier for calculating the Titration Curve of complicated complex systems and the theory was extended slightly to cover inhomogeneous redox system.
14 citations
TL;DR: In this article, the melting point curves for solutions of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in a series of homologous solvents (toluene to n-hexylbenzene) have been obtained from visual and differential scanning calorimetry measurements.
Abstract: Melting-point curves for solutions of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) in a series of homologous solvents (toluene to n-hexylbenzene) have been obtained from visual and differential scanning calorimetry measurements. The measured melting points were used to calculate thermodynamic interaction parameters. It was found that consistent values were obtained with the Flory-Hoffman melting-point depression equation, if the assumption was made that solvent molecules are incorporated in the crystal lattice. To this end, an adapted dependence of the enthalpy of melting per polymer unit on the cocrystallizing solvent was used. The values of the thermodynamic interaction parameters in the series of solvents and their dependence on polymer weight fraction are explained qualitatively with simplified versions of equation-of-state theory and solubility parameter theory.
12 citations
TL;DR: In this article, a flow-through cell is equipped with a mercury-coated gold electrode as the working electrode, and the calibration graph is not linear but with an approximation by a polynomial or a cubic spline function, correct results can be obtained with an accuracy of *4%.
TL;DR: In this article, a general method for determination of the stability constants of crown ethers and related compounds with small organic molecules in polar solvents is described, based on an indirect polarographic procedure.
TL;DR: The adsorption behaviour of two commercial preparations of human IgG onto a polystyrene latex surface was studied and showed differences between the two preparations, stressing the necessity for proper characterization of proteins used in advertisersorption studies.
TL;DR: In this paper, loss measurements have been performed on a superconducting transformer with a microcomputer sampling four relevant signals and processing these data to reliable loss numbers at amplitudes of the secondary current between 5 and 15 kA at various current rates between 5, 30 kA s−1.
TL;DR: A precise x-ray fluorescence method for the determination of sulphur in coat is described in this paper, where a sample is mixed with calcium oxide and active carbon and is gradually heated to 900°C.
TL;DR: A procedure is proposed for the determination of malononitrile by differential pulse polarography in methanolic 0.1M tetraethylammonium iodide/0.001M tetramethylamMonium hydroxide as the supporting electrolyte with close control of timing of the steps.