Effects of experimental conditions

TABLE 10.3 Effects of Experimental Conditions on the Depolymerization Efficiency of Nylon-4,6... 

Studies of Con A induced agglutination of live cells are susceptible to complications such as irreversibility of the agglutinated cells upon aging (17), endocytosis of bound lectin (18) and effects of experimental conditions such as temperature, pH and ionic strength on membrane properties (J). Alternatively, the use of aldehyde-fixed cells (19), heatkilled cells (20), enucleated cells (21) and glycoprotein-incorporated liposomes (22) may lead to less problems being encountered. 

The use of dextran gel spheres allows the effects of experimental conditions on agglutination to be studied relatively free of complications due to undefined changes in system properties. Variations in the ability of Con A to induce agglutination under different conditions as aforementioned, are attributed to the tetramer-dimer transition of the Con A molecule. Lack of agglutination is directly correlated with the conversion of Con A from the active tetramer form to the inactive dimer species. The results of this study support earlier contentions (6 8) that the effects of temperature on cell agglutination cannot be interpreted exclusively in terms of changes in cell surface properties. 

Sichel C, Blanco J, Malato S, Fernandez-Ibanez P. Effects of experimental conditions on E. coli survival during solar photocatalytic water disinfection. J Photochem Photobiol A Chem 2007 189 239 i6. 

Graft copolymerization reactions of fibrous cellulose with vinyl monomers were initiated at free radical sites formed on the cellulose molecule by interaction with radiation, by reaction with Ce4+ ions in acidic solution, or by H abstraction by OH radicals formed by reaction of Fe2+ ions with H202 in aqueous solution. The effects of experimental conditions on the location of these sites on the cellulose molecule and on the reactions were studied by ESR spectroscopy. The molecular weights of the grafted copolymers and the distribution of the polymers within the fibrous cellu-losic structure were determined. Some of the properties of the copolymers are discussed. 

TABLE 1. Effect of experimental conditions on the film thickness of polypyrrole. 

Blacet and Volman have studed, in detail, the temperature, pressure, and intensity dependence of the H2/CO ratio. The effect of experimental conditions on this ratio was traced to the changes in the chain length. Calvert et investigated the dependence of on the temperature at 3130 A. These results are summarized in Fig. 7, from which it is evident that 4>n attains a limiting value at high... 

S. Mori, Effect of experimental conditions, in Steric Exclusion Liquid Chromatography of Polymers (J. Janca, ed.), Marcel Dekker, Inc., New York, 1984. 

Felinger and Guiochon used the equilibrium-dispersive model to study the effect of experimental conditions on the maximum production rate and Pr xY [40,41]. We have seen in Section 18.2.3 that in isocratic elution chromatography, the loading factor and the column efficiency are the critical parameters to be optimized for maximum production rate. In gradient elution there is an additional parameter, the gradient steepness... 

In the mass titration method, the PZC is determined as the natnral pH of a concentrated dispersion. A detailed description of the experimental procedure can be found in [667], Mass titration become popular in the late 1980s [668,669], but the same method was already known in the 1960s as the pH drift method [183], Usually, a series of natural pH values of dispersions with increasing solid loads is reported, but only the natural pH of the most concentrated dispersion is actually used. The only role of the data points obtained at lower solid loads is to confirm that a plateau was reached in pH as a function of solid load that is, a further increase in the solid load is unlikely to bring about a change in pH. The mass titration method is based on the assumption that the solid does not contain acid, base, or other surface-active impurities. This is seldom the case, thus mass titration often produces erroneous PZCs. In this respect mass titration is similar to the potentiometric titration without correction illustrated in Figure 2.7, only the solid-to-liquid ratio is different. The experimental conditions in mass titration (solid-to-liquid ratio, time of equilibration, nature and concentration of electrolyte, and initial pH) can vary, but little attention has been paid to the possible effects of experimental conditions on the apparent PZC. The effect of an acid or base associated with solid particles on the course of mass titration was studied in [670], To this end, a series of artificially contaminated samples was prepared by the addition of an acid or base to a commercial powder. The apparent PZC of silicon nitride obtained in [671] by mass titration varied from 4.2 (extrapolated to zero time of equilibration) to 8.2 for time of equilibration longer than 20 days. The method termed mass titration was used in [672], but it was different from the method discussed above. 

Tensile properties of composite propellants depend on the tensile properties of the matrix, concentration of the components, particle size, particle-size distribution, particle shape, quality of the interface between fillers and polymeric binder, and, obviously, experimental conditions (strain rate, temperature, and environmental pressure). Many authors (2, 3) have explained the effect of fillers on the mechanical properties of composites, the importance of the filler-matrix interface on physical properties, and the mechanism of reinforcement of the material. Other efforts have examined the effect of experimental conditions on the failure properties of filled elastomers. Landel and... 

Results of scouting grafting onto experiments indicated that soluble poly(butadiene- -styrene) s can readily and quite efficiently be obtained by effecting styrene polymerization with the r-BuCl/Et2 A1C1 initiating system in the presence of various polybutadienes. Thus it appeared of interest to follow up this lead and to investigate the mechanism of this technique, in particular to elucidate the effect of experimental conditions on grafting details. 

Experiments have been carried out to substantiate the comprehensive closed-loop model described in Sect. 2. The experiments included the determination of kc and kp under various conditions including a study of the effect of temperature on these parameters, an examination of the effect of experimental conditions on M and Mw/M together with an analysis of the GPC traces obtained. The raw data are shown in Tables 2-8 in the Appendix. 

The Effect of Experimental Conditions on Molecular Weights and Molecular Weight Dispersides GPC Studies... 

Effect of Experimental Conditions during Irradiation on Radiation Inactivation Size of... 

The clusters can be formed from graphite by laser evaporation, stabilized by expansion through a supersonic nozzle, and analyzed as ions by using laser ionization and mass spectrometry (42-44). In all of these experiments, even-numbered clusters, and in particular a species, are prevalent and presumably relatively stable. Some controversy has developed in regard to the effect of experimental conditions or charge on the cluster size distribution... 

Ahmad, T.A., Chaplin, A.E., 1984. The effect of experimental conditions on the activity of pyruvate kinase from the aductor muscle of the mussel Mytilus edulis (L). J. An. Morphol. Physiol. 31, 107-118. 

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