Gradient concept

The gradient concept here is different from the mathematical gradient. This concept of gradient is also applicable to a column of a solid. 

The mechanism of movement was also confirmed to be similiar. Catchmark was able to control hydrophobicity of the gold through different wet chemistries, thereby demonstrating that a hydrophobic gold surface is necessary for movement to occur. This is in agreement with the interfacial tension gradient concept in that a hydrophobic gold surface is necessary to observe platinum end forward movement. 

In comparing the concentration gradient concept with subsequent chemical suppression, the chromatogram of various inorganic anions in Fig. 3-127 that was obtained with isoconductive eluents clearly shows the limitation of this technique. Although the analysis time for the separation shown is shorter than under isocratic conditions, an improvement in the resolution between the signals, especially in the first part of the... 

Part I Strong Field Gradients , Concepts Magn. Reson., 2000,12, 188 R299 D. E. Demco and B. Blumich, Solid-State NMR Imaging Methods. 

The gradient concept can be applied also in SMB chromatography. This approach was first suggested for separations using supercritical fluids (Clavier, Nicoud, and Perrut, 1996). It is capable of increasing productivity and product concentrations, as well as of reducing eluent consumption. Theoretical and experimental studies... 

The presented model calculations indicate that, indeed, the concentration gradient concept based on a polymorphic nucleation mode may quantitatively describe the observed retardation of the first product AI9C02 in the case of Al-Co. However, this statement is boruid to the curvature of the Gibbs potential of the intermetallic phase. It is important to check whether the figures used for the calculation, with a of about 10 J/atom, are reasonable. Since no direct measurements or expHcit calculations of the respective Gibbs energy function are known, we have... 

Figure 3 A 2D spatial X-band image of four specks of solid DPPH. Sixty EPR spectra were obtained with maximum field gradients 5 /5z = 10 mT cm- and 5Bz/5y= 6 mT cm-. The spectra constitute a fuii set of projections over 180°. Reproduced with permission from Eaton GR and Eaton SS (1995) Introduction to EPR imaging using magnetic-field gradients. Concepts in Magnetic Resonance 7 49.

As expected, the effect of electron correlation on computed intensities has been initially treated by evaluating dipole moment derivatives through numerical differentiation [182,183]. The finite difference method of Komomicki and Mclver [178] offo another possibility. Simandiras et al. [184] have later developed a complete formulation for deriving analytic dipole moment derivatives at the second order Moller-Plesset (MP2) level. An alternative approach based on the configuration interaction (Cl) gradient concept [185] has been put forward by Lengsfield et al. [186]. 

All modern whisker growth theories make similar statements, but do not emphasize a positive stress gradient concept. 

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