Polar probability plot

Fig. 3. Section through a polar probability plot of a uniaxial orientation...

The effect of ultrasound on the process of tellurium anodic dissolution in alkaline solutions was studied by the method of plotting polarization and galvanostatic curves [148]. Tests were made in NaOH solutions (concentrations of 0—20 g/L), subjected to the action of ultrasound at a frequency 17.5 kHz and using Te electrodeposited under ultrasound. The anodic polarization curves plotted without ultrasound and in its presence shifted with increased NaOH concentration towards negative values as a result of the increasing rate of Te anodic dissolution. The presence of ultrasound inhibited the process of Te anodic dissolution, probably due to the desorption of OFT anions from the anode surface. This sonoelectrodeposited Te thus showed greater corrosion resistance in alkaline solution than that deposited... 

Figure 7.61 Normal probability plot of the pitting potentials of different ferritic stainless steels measured by potentiodynamic polarization in 3.5% NaCl at 30 °C under nitrogen atmosphere. Potential scan rate 16.7 mV min" [23].

The presence of a transporter can be assessed by comparing basolateral-to-apical with apical-to-basolateral transport of substrates in polarized cell monolayers. If P-gp is present, then basolateral-to-apical transport is enhanced and apical-to baso-lateral transport is reduced. Transport experiments are in general performed with radioactively labeled compounds. Several studies have been performed with Caco-2 cell lines (e.g. Ref. [85]). Since Caco-2 cells express a number of different transporters, the effects measured are most probably specific for the ensemble of transporters rather than for P-gp alone. P-gp-specific transport has been assayed across confluent cell layers formed by polarized kidney epithelial cells transfected with the MDR1 gene [86], Figure 20.11 shows experimental data obtained with these cell lines. A rank order for transport called substrate quality was determined for a number of compounds [86]. The substrate quality is a qualitative estimate, but nevertheless allows an investigation of the role of the air/water (or lipid/water) partition coefficient, log Kaw, for transport as seen in Fig. 20.11(A). For most of the compounds, a linear correlation is observed between substrate quality and log Kaw- However, four compounds are not transported at all despite their distinct lipophilicity. A plot of the substrate quality as a function of the potential of a... 

From the plots of the rr-charge densities of the carbon atoms of the purine and pyrimidine residues of nucleosides versus chemical shift values a gross correlation is obvious. Different calculations of the -densities, however, yield different plots. The n-electron densities calculated by Hoffmann and Ladik [763] by the HMO method or those calculated by Veillard and Pullman [764] by the Pariser-Parr SCF method show the strongest deviation for C-4, most probably because amplified C —N bond polarization terms have to be used for the calculations. 

Figure 30 shows such a plot for Pair A13) in which the C02 axes are 29° from each other, and the coupling constant is 4.74cm-1. For this plot, At was placed at the origin of polar coordinates in the orientation determined by polarized IR studies. In the orientation determined by polarized IR and in van der Waals contact with At, A3 was initially set on the polar axis, and its position was varied in 10° increments of longitude (8) and latitude (). The electronic distribution, calculated with a 6-31G basis set, predicts a transition moment of 13.6 D/A, which is slightly larger than the experimental gas phase value 51], Since the transition dipole of polycrystalline C02 is much smaller (7.84 D/A), the calculation probably overestimates the... 

Shin [24] has utilized a semiclassical approach to examine orientational effects on vibrational excitation. He treats the problems of (XX-A) and (XY-A) collisions, where A is an atom interacting with atoms of a diatomic molecule XX or XY through a Morse potential, and also the problems of (XX-XX) collisions and (XY-XY) collisions. The orientation dependence of the transition probabilities for Oa-Ar, 02-02, HBr-Ar, and HBr-HBr are plotted in polar diagrams. It is found, for example, that in the latter case only a very small range of angles gives the greatest contribution, namely, around that orientation in which the two H atoms lie between the Br atoms. 

Fig. 28.1. In a genetic switch, the total state of the system depends on two variables whether the DNA site is occupied or not and the number of copies of the transcription factor. In the left panel, the logarithm of the steady state probability for the occupancy state and protein number is plotted. This probability acts like an effective potential. In the right panel, the effective potential for a charge transfer or two site polaron is plotted as a function of the enviromnent polarization for the two electronic states. The governing time-dependent eqnations for the two problems share many similarities...

Fig. 2. Orientational probability distributions of the molecular axes in (a) a-nitrogen and (b) y-nitrogen. Contours of constant probability for the molecule in the origin, calculated in the mean field model, are plotted as functions of the polar angles (0, ) with respect to the crystal axes (Fig. 1). The angle 0 increases linearly with the radius of the plots from 0 (in the center) to tt72 (at the boundary) d> is the phase angle.

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