Magnetic field effects ratio

By subtraction of the equal term from z rcr and sCs the two rates become smaller, but their ratio becomes larger and there should be a larger k. The authors searched for an enhancement of ee in the cpl-photoreaction of 2-phenylcyclohexa-none 27, 2-phenylcycloheptanone 28 and 2-phenylcyclooctanone 29, but found no magnetic field effect. 

The proposed reaction mechanism of phenols with O2 catalyzed by Co-amine complexes is shown in Scheme 47. On oxidation of 2,6-dimethylphenol (206) to 2,6-dimethyl-p-benzoquinone (223), magnetic field effects in the cobalt(II)-catalyzed oxidations were examined by using two different high- and low-spin cobalt(II) complexes. The former complex, Co bis(3-(salicylideneamino)propyl)methylamine, Co SMDPT (S = 3/2), displays a maximum increase in the initial rate of ca 1000 G, while the low-spin cobalt complex, Co iV,iV -bis(salicylidene)ethylenediamine, Co salen (S = 1/2), in a 1 10 ratio with pyridine displays a maximum decrease in the initial rate at ca 800 G. The difference in the magnetokinetics of both complexes is explained by magnetic field effects on the singlet-triplet (S-T) radical pair and triplet-triplet (T-T) annihilation reactions... 

Superficially, these estimates correlate well with the energy dependence of the singlet ratio determined from the magnetic field effects on the solute... 

Figure 3. Magnetic field effect on the relative yield of in RCII complexes. The ratios (AA( is)/AA(ns)) of the initial amplitudes of the ns and )xs signals, recorded as in Figs. 1 and 2, respectively, were normalized to the zero-field value and plotted versus field strength. Symbols are for different samples.

Industrial exposure to electric fields is t5q)ically lower than exposures to magnetic fields when compared to residential electric field/magnetic field exposure ratios. The reason for lower electric fields in the presence of heavy electrical equipment appeared to be the effective shielding provided by metal. PI... 

Fig. 8.9 Semilogarithmic plot of the ratio of fluorescence intensity obtained in the simulation (line) and adjacent average smoothing (circle) using 2 pairs (cyan) 5 pairs (magenta) 10 pairs (green) and 15 pairs (blue). Cations were linearly distributed with a mean spacing of a 40 A c 100 A and e 150 A. In b, d and f the solid red line is the analytically calculated magnetic field effect using the T values in Table 8.8, with T2 5 ns. Anions were distributed using a Gaussian distribution with mean zero and standard deviation of 80 A. A mutual diffusion coefficient (D ) of 0.325 A ps was used for S7 / c-RH+...

Reactions which have occurred at zero time are replaced by their reactive products (if applicable). For all surviving species reactions times are generated from a model distribution conditioned on the radical pair separation distance. The fluorescence intensity I (t) (which is the experimentally observable quantity) is detected as D D [reaction (10)] and D [reaction (7)] to allow better statistics to be obtained. The simulation is therefore run twice, one with zero field parameters and one using high field parameters the ratio of I sit)/hit) is then obtained to observe the magnetic field effect. In the simulation, no T or relaxation mechanism was assumed to take place at high fields (unless otherwise stated). For zero field calculations Tq was assumed to be equal to T2 with the spin-spin relaxation time set to a value of 30 and 9 ns for S+ and D+ respectively. These values are based on the analysis by Borovkov on the rate of electron self-exchange [34, 41, 42] for S+ and D+, with... 

Magnetic analyzer. A direction-focusing device that produces a magnetic field perpendicular to the direction of ion travel. The effect is to bring to a common focus all ions of a given momentum with the same mass-to-charge (m/z) ratio. 

Figure 8 Effects of spin diffusion. The NOE between two protons (indicated by the solid line) may be altered by the presence of alternative pathways for the magnetization (dashed lines). The size of the NOE can be calculated for a structure from the experimental mixing time, and the complete relaxation matrix, (Ry), which is a function of all mterproton distances d j and functions describing the motion of the protons, y is the gyromagnetic ratio of the proton, ti is the Planck constant, t is the rotational correlation time, and O) is the Larmor frequency of the proton m the magnetic field. The expression for (Rjj) is an approximation assuming an internally rigid molecule.

An MR hydrogel of a crosslinked PVA network and Fe304 particles dispersed at random was also synthesized [59]. The viscosity of the gel in a magnetic field increased with time. It has been suggested that the dispersed Fe304 particles aggregate and form a cluster. The effect of the volume fraction of the particles on the viscosity has also been discussed. The authors have pointed out that when the volume fraction is about 15%, the ratio of the viscosities with and... 

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