Molecular weight effective

Assuming the effective molecular weight of the solvent is significantly less than that of the protein/peptides, then equation (17) can be reduced to... 

TABLE I l.l Effective Molecular Weight Ranges for Styragel HR Packings... 

Fig. 9. The effect of interpolymer complexation on the correlation length, , and the effective molecular weight between crosslinks, Mc, in P(MAA-g-EG) graft copolymer networks with permanent, chemical crosslinks ( ).

The existence of aggregates is evidenced by virial coefficients wh ch are lower than the theoretical values, for the measured M,. This is because the second virial coefficient decreases with increasing molecular weight. Supermolecular aggregates appear to have very high effective molecular weights. 

Gupta et al. (3) reported that elcistically effective molecular weight between crosslinks. Me, was lowest at the stoichicnetric ratio of MPD and epoxy, and post curing resulted in a considerable decrease in Me only in epoxy rich sanples (3). 

Unfortunately such "effective molecular weight studies involve the major assumption that the whole deviation from ideal solutions is due to association and this assumption can only be controlled by some non-osmotic method such as the spectrophotoraetric one. Dolezalek s papers of the 19)0 era provide ample warning of the falsity of this assumption when indiscriminately applied however, where associative interaction is pronounced, comparison of spectroscopic and osmotic data shows that the careful evaluation of the latter leads to essentially correct results. 

Several configurations for the sensor are possible. An especially viable alternative would seem to be the competitive displacement of fluorescent label. Since this is an equilibrium, fouling or contamination of the surface should not alter the absolute result. Krull et al (75) have reported the reproducible immobilisation of a stable phospholipid membrane containing fluorophore in this context. Concurrent fluorescence polarisation measurements can offer the possibility of multidimensional analysis (76) and are in any case experiencing a rejuvenation of interest as a highly selective technique, when the effective molecular weight of the antibody is increased relative to the antigen, by immobilisation on a latex or metal particle (77)... 

Figure 15.12 Slopes P=A/(X2-X 1) plotted versus the effective molecular weight between crosslinks Mc and the elastic modulus Ge, obtained from swelling measurements, in series of PDMS networks with various precursor chain lengths and elastic chain fractions network chains only are deuterated (observed) O dangling chains only are deuterated free probe chains only are deuterated...

For a Tg to occur in crosslinked systems, there must be sufficient molecular mobility to affect the macroscopic physical modulus of the material. As the effective molecular weight, between the crosslinks decreases with increasing crosslink density, the thermal activation required to induce sufficient molecular movement, seen by a Tg, is commensurably increased. 

If temperature does not change with height, estimate the boiling point of water at a height of 3000 m above sea-level. The barometer reading at sea-level is 98.4 kN/m2 and the temperature is 288.7 K. The vapour pressure of water at 288.7 K is 1.77 kN/m2. The effective molecular weight of air is 29 kg/kmol. 

FIGURE 4-5. Effective molecular weight range and column type for size separations (a) and an example chromatogram of a gel permeation separation (b). 

ASSUMPTIONS AND DATA. The effective molecular weight of the oil may be assumed to be 150. The vapor pressure of the oil is negligible under the conditions of the process. 

Table I summarizes comparisons between asphaltenes derived from bituminous coal liquefaction and those derived from petroleum crudes. The molecular size and atomic H/C ratios suggest a molecular profile quite different for the two asphaltenes. The ranges represent, as best as could be found, reasonable extremes for each of the properties. We are well aware that the number-average molecular weight of petroleum asphaltenes has been influenced by aggregate formation. To overcome this effect, molecular weight determinations should be made in dilute noninteracting solvents (e.g., methylene chloride), and solutions should be filtered or ultracentrifuged in helium-degassed solvents.

As far as the craze drawing lifetime (Fig. 4) was concerned, estimation was certainly rather more subjective. Nevertheless, two series of tests interpreted by two different experimenters produced similar results, their estimates were supported independently by their supervisor, and neither experimenter knew of the values which would be predicted by the model. For this material Af = 310k density, specific enthalpy and thermal conductivity were known as functions of temperature and the craze stress measured using full notch impact tests was in the range 20-30 MPa. Figure 5 compares the measured decohesion times to those predicted by the model, plotted as trend lines for two constant values of cohesive stress — 20 and 50 MPa — and two values of effective molecular weight (which has only a secondary effect). 

This equation incorporates the effective molecular weight (Meff) contributing to OP photonic properties. Meff is often significantly smaller than the number... 

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