Spatial enhancement

Another practical CARS technique places the Stokes beam inside the pump beam when using a Nd YAG laser with Donut profile as pump laser source (Marko and Rimai, 1979). This method which has been termed USED (unstable resonator spatially enhanced detection) CARS (Eckbreth et al,. 1984 Eckbreth and Anderson, 1985) also increases the spatial resolution. 

To complete the optimal planar dividing surface VTST, it is necessary to express all quantities in the continuum limit. It is useful to define an average spatial enhancement coefficient as... 

For space-independent friction g(q) - q so that the average spatial enhancement coefficient is unity. Any deviation of from unity is thus due to the effect of the space dependence of the friction. One now finds that the th transformation coefficient is... 

A study of the effects of space-dependent friction and time-dependent friction was presented in Ref. 29. One finds that when the friction is stronger in the well than at the barrier, the spatial enhancement factor becomes substantially larger than unity, again leading to a substantial reduction of the rate relative to the parabolic barrier estimate. In all cases, the effects become smaller as the barrier height measured in units of kHT becomes larger. Comparison with molecular dynamics simulations shows that the optimal planar dividing surface estimate for the rate is essentially exact. 

Spatial Enhancement 72 Unsharp Masking 72 Adaptive Histogram Equalization 73 Multiscale Image Enhancement 74 Peripheral Enhancement 75... 

Of the spatial enhancement methods, contrast-limited adaptive histogram equalization (CLAHE) has frequently been used in observer experiments. Hem-MiNGER et al. studied whether detection of simulated masses in dense mammograms could be improved with the technique and compared the effects of this... 

A wavelet technique for spatial enhancement of microcalcifications in mammograms was evaluated by Kallergi et al. (1996). Digitized mammograms were... 

K. Wang, H. Begleiter, and B. Potjesz, Spatial enhancement of event-related potentials using multiresolution analysis. Brain Topogr. 10 191-200 (1998). 

This Is a two beam, three-dimensional phase matching technique particularly convenient for practical application. The acroi m USED stands for nstable-resonator spatially enhanced detection. 

Hamann H F, Gallagher A and Nesbitt D J 1999 Enhanced sensitivity near-field scanning optical microscopy at high spatial resolution Appl. Phys. Lett. 75 1469-71... 

In contrast to the situation in the absence of catalytically active Lewis acids, micelles of Cu(DS)2 induce rate enhancements up to a factor 1.8710 compared to the uncatalysed reaction in acetonitrile. These enzyme-like accelerations result from a very efficient complexation of the dienophile to the catalytically active copper ions, both species being concentrated at the micellar surface. Moreover, the higher affinity of 5.2 for Cu(DS)2 compared to SDS and CTAB (Psj = 96 versus 61 and 68, respectively) will diminish the inhibitory effect due to spatial separation of 5.1 and 5.2 as observed for SDS and CTAB. 

In contrast to SDS, CTAB and C12E7, CufDSjz micelles catalyse the Diels-Alder reaction between 1 and 2 with enzyme-like efficiency, leading to rate enhancements up to 1.8-10 compared to the reaction in acetonitrile. This results primarily from the essentially complete complexation off to the copper ions at the micellar surface. Comparison of the partition coefficients of 2 over the water phase and the micellar pseudophase, as derived from kinetic analysis using the pseudophase model, reveals a higher affinity of 2 for Cu(DS)2 than for SDS and CTAB. The inhibitory effect resulting from spatial separation of la-g and 2 is likely to be at least less pronoimced for Cu(DS)2 than for the other surfactants. 

As mentioned earlier, there is an inverse relationship between water volumes and oxygen concentration in soil. As soils dry, conditions become more aerobic and oxygen diffusion rates become higher. The wet-dry or anaerobic-aerobic alternation, either temporal or spatial, leads to higher corrosion rates than would be obtained within a constant environment. Oxygen-concentration-cell formation is enhanced. This same fluctuation in water and air relations also leads to greater variation in biological activity within the soil. 

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