Current density mapping

The criterion of ipsocentric ring current has been used to assess aromaticity in S-N heterocycles (and related inorganic ring systems). Current density maps indicate that the ten r-electron systems [SsNs], [S4N3] " and [S4N4] ", and the fourteen r-electron system [S5N5] " support diatropic k currents, reinforced by a circulations. 

Figure 22. SVET current density map over carbon steel after 23 hr of exposure to aerobic bacteria. (Reprinted from Ref. 39 with permission from NACE International.)...

Fig. 2.9.2 Radiofrequency, field gradient and current distributions requires a three-dimen-ionic current pulse sequences for two-dimen- sional imaging sequence [see Figure 2.9.1(a)] sional current density mapping. TE is the Hahn and multiple experiments with the orientation spin-echo time, Tc is the total application time of the sample relative to the magnetic field of ionic currents through the sample. The 180°- incremented until a full 360°-revolution is pulse combined with the z gradient is slice reached. The polarity of the current pulses...

Ionic current density maps can be recorded with the aid of the pulse sequence shown in Figure 2.9.2. The principle of the technique [48-52] is based on Maxwell s fourth equation for stationary electromagnetic fields,... 

Fig. 2.9.13 Qu asi two-dimensional random ofthe percolation model object, (bl) Simulated site percolation cluster with a nominal porosity map of the current density magnitude relative p = 0.65. The left-hand column refers to simu- to the maximum value, j/jmaK. (b2) Expedited data and the right-hand column shows mental current density map. (cl) Simulated NMR experiments in this sample-spanning map of the velocity magnitude relative to the cluster (6x6 cm2), (al) Computer model maximum value, v/vmax. (c2) Experimental (template) for the fabrication ofthe percolation velocity map. The potential and pressure object. (a2) Proton spin density map of an gradients are aligned along the y axis, electrolyte (water + salt) filling the pore space...

MSB current density map over a predefined magnet domain, where superconducting coils will be laid out, subject to constraints, such as the homogeneity of the FOV and footprint of the magnet stray field. 

Magnet arrangement with the initial coil layout based on the MSB current density map. The coil locations and sizes are refined to enhance the field homogeneity and to decrease the footprint of the magnet, without changing the original constraints defined for the MSB current density map. 

Figure 3 Illustration of different MSE current density maps. Given are MSE current density maps of (A) order 10 degree 0 for a 3-m length symmetric magnet domain,...

The coil structures are initially positioned coincident with the positive maxima and negative minima of the MSE current density map with their initial cross sectional areas being proportional to the value of the associated current densities. The coil locations and dimensions are then... 

In the MSE approach, the size and field homogeneity of the FOV are proportional to number of zeroed inner spherical harmonics, and number of vanished outer harmonics defines the size of the system footprint. We recall that the number of inner and outer spherical harmonics made to vanish refers to the order and degree of the design. Once the order and degree are specified based on the requirements of the FOV and the stray field, and the magnet domain has been established, then the MSE current density map is calculated. 

Figures 4A, 5A, 6A and 7A depict current density map contour plots along with the placement of the seed coils used for the second stage optimization. The seed coils are placed at local positive maxima and negative minima of the MSB current density map. The current direction of each coil is defined by the polarity of these local extremities. It is also important to mention that the local extremities in the MSB current density...

Figure 4 The IT order 14 degree 4 magnet design. Illustrations of (A) the MSE current density map distribution with locations for initial seed coils, (B) the total magnet field distribution, (C) the final coil layout and associated inner field, (D) the outer field cut-off with 20,15,10, and 5G contours from inside out and (E) the stress with respect to the radial direction inside each of the coils. The + signs in (C) indicate positive transport current, otherwise the transport current is negative and the contours correspond to the field in (B).

Optimization at the restricted Hartree-Fock (RHF) and DFT (B3LYP) levels in the 6-31G basis set has also contributed to structural clarification of [l,2,5]thiadiazolo[3,4-f][l,2,5]thiadiazole 6 both approaches successfully predict that 6 ought to have planar equilibrium geometry. Direct a3 initio ipsocentric calculations of the total 7t-current density map for 6 permits classification as aromatic according to magnetic criteria. It exhibits a strong and uniform diatropic perimeter circulation, of comparable intensity to the parent monocycle 11 and similar to that of naphthalene <2004JA11202>. 

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