Mobility data

Where mobility data are available over a considerable range of temperature, the activation energy is often found to be temperature-dependent. Thus, in n-pentane the activation energy increases with temperature whereas in ethane it decreases (Schmidt, 1977). Undoubtedly, part of the explanation lies in the temperature dependence of density, but detailed understanding is lacking. In very high mobility liquids, the mobility is expected to decrease with temperature as in the case of the quasi-free mobility. Here again, as pointed out by Munoz (1991), density is the main determinant, and similar results can be expected at the same density by different combinations of temperature and pressure. This is true for LAr, TMS, and NP, but methane seems to be an exception. 

Lande, S.S., Hagen, D.F., Seaver, A.E. (1985) Computation of total molecular surface area from gas phase ion mobility data and its correlation with aqueous solubilities of hydrocarbons. Environ. Toxicol. Chem. 4, 325-334. 

Mobility data on bipolar charge-transport materials are still rare. Some bipolar molecules with balanced mobilities have been developed [267], but the mobilities are low (10 6—10 8 cm2/Vs). Up to now, no low molecular material is known that exhibits both high electron and hole conductivity in the amorphous state, but it is believed that it will be only a matter of time. One alternative approach, however, is to use blends of hole and electron transporting materials [268]. 

PARTITION COEFFICIENTS (P ), RETENTION FACTOR (K) AND MOBILITY DATA OF DYE INTERMEDIATES MEASURED WITH A PHOSPHATE-(TTAB) BUFFER AT PH 5.0 ... 

The lack of ionic mobility data causes a serious inconvenience when the ion conduction ability of an electrolyte is evaluated, because the measured conductivity is the result of the overall migration of both anions and cations, while for lithium batteries only the portion of the current that was carried by the lithium cation matters. This portion of the current from lithium ion movement, which determines the... 

All these methods benefit from the different behavior of free vs. bound substrate. Association involves changes of molecular size and/or charge, which controls electrophoretic mobility. Capillary electrophoresis provides mobility data as well as analytical concentrations with a minimal consumption of substances. During the past decade a variety of methods have been developed using mobility data or direct concentration readings from the detector to get information on the association constants (2-4). 

Fig. 3 Scatchard plots of mobility data for second-order binding with different coopera tivities.

Provided the mobilities of the different protein-drug complexes are nearly the same, but different from the free drug, r and n can be calculated from the mobility data, analogously to Eq. (14) ... 

Regression analysis of the pH-metric mobility data to obtain pKa. 

Data for step-mobilities shown in Fig. 6 span an impressively large range a factor of 10 " separates step-mobilities measured by STM from the step-mobilities extracted from the relaxation of micron-sized gratings. Some discrepancies exist, but most of the step-mobilities are consistent with a single activation energy of 1.8 eV and an attempt rate given by the frequency of atomic vibrations. We hope that this initial comparison of step-mobility data will help motivate more detailed theoretical analysis and experiments on the coimections between step-mobility and the evolution of surface morphology. 

The prerequisites of the evaluation of data characteristic of intracrystalline processes in the case of zeolite sorbents are discussed, along with the conditions under which diffusion can be compared to self-diffusion. Selected results of investigations carried out in the author s laboratory are given in order to demonstrate the consistency of sorption kinetic data with intracrystalline mobility data of single components on molecular sieves (HS). Various types of surface barrier which may influence the uptake rate are also described. 

The intracrystalline mobility data for theibenzene / NaX type zeolite systems are supported by our sorption uptake results for the systems... 

In the study of Neirynck et al. (2007), the electrophoretic mobility data indicated that whey protein-stabilized emulsion droplets became gradually more negatively charged with pectin addition at pH = 5.5. This change was not only reflected in a smaller average droplet size, but also in a significant improvement in the creaming stability of the emulsions. 

To evaluate + for each metal ion, values of p8 are required at each concentration. While this can often be evaluated from electrophoretic mobility data, the high ionic strengths—Le., pH < 2—preclude meaningful measurement of mobilities. However, it can be seen that when ij/s and cf)+ are equal and opposite then adsorption is reduced to zero. The adsorption of Na+ is reduced to zero at the z.p.c. since, in this case, + is negligibly small. With Ni2+ and Cu2+ the pH must be reduced—i.e., made more positive—by 1.3 pH units to effect zero adsorption. Since near the z.p.c. ips and i//0, the total double layer potential, are approximately equal and given by the Nernst Equation, then... 

Figure 7.7 Zeta potentials (calculated from electrophoretic mobility data) relating to particles of different ionogenic character plotted as a function of pH in acetate-veronal buffer at constant ionic strength of 0.05 mol dm 3, (a) Hydrocarbon oil droplets, (b) Sulphonated polystyrene latex particles, (c) Arabic acid (carboxylated polymer) adsorbed on to oil droplets, (d) Serum albumin adsorbed on to oil droplets...

Analysis of gel electrophoretic mobility data is based on the basic idea is that ordered sequences are compact. Compact molecules migrate faster in the gel matrix [115, 116]. But random RNA sequences have a disposition to acquire multiple conformations. Only some of these conformations may be compact [115, 116]. Furthermore, when the RNA constructs are run on gels in the presence of magnesium ions, some of the conformations undergo nonspecific collapse due to condensed counterions [115, 116]. 

The mobility and resistivity data of single crystalline zinc oxide samples (measured at room temperature) from different authors, which were reported from 1957 to 2005, are displayed in Fig. 2.6 as a function of the carrier concentration (part of these data were taken from [67]). Undoped ZnO crystals exhibit carrier concentrations as low as 1015 cm-3, while indium-doped crystals reach carrier concentrations up to 7 x 1019cm-3. The mobility data show a large scattering between carrier concentrations of 1017 to 5 x 1018cm-3. This is caused by the fact that zinc oxide is a compound semiconductor that is not as well developed as other semiconducting compounds. For instance, only... 

For polycrystalline films this limited understanding is nicely illustrated by our own mobility data for Al-doped ZnO films (see Fig. 2.15) deposited both on glass and sapphire substrates as a function of the carrier concentration... 

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