Planar slice

Figure 9.10 Three-dimensional representation of the data volume of a tryptic digest of ovalbumin. Series of planar slices through the data volume produce stacks of disks in order to show peaks. Reprinted from Analytical Chemistry, 67, A. W. Moore Jr and J. W. Jorgenson, Comprehensive three-dimensional separation of peptides using size exclusion chromatogra-phy/reversed phase liquid chromatography/optically gated capillary zone electrophoresis, pp. 3456-3463, copyright 1995, with permission from the American Chemical Society.

Figure 5.3 Planar slices through the Gibbs USX surface (cf. Fig. 5.2) for (a) U = constant, (b) S = constant, showing that the chosen equilibrium state (small circle) is a maximum in the first case (Su curve, heavy line) but a minimum in the second case (Us curve, heavy line).

Objects are usually three-dimensional, and often 2D slices through an object need to be imaged. Magnetization from voxels defining the slice of interest can be selected in different ways. What is required is selective excitation and a field gradient. If a planar slice is to be selected, the field gradient is... 

The determination of phase change is primarily based on changes in the orientational order parameter P2 t)- This parameter measures the degree of alignment of the chains, for all united atoms in the system. To measure the size or transformation of the crystal or amorphous phase, the order parameter is computed locally, such that orientational order can be measured as a function of position, P2 r,t), or as a function of one dimension (i.e. within planar slices), such as P2 x,t) or P2 z,t). The method of calculation of the orientational order parameter, as well as its comparison to order parameters based on density and energy, has been previously discussed [30,35]. 

Angular momentum vectors of the Y, states of the rigid rotator for Z = 1 (solid lines), I = 2 (dashed lines), and I = 3 (dotted lines). The arrows represent the orientation with respect to the z-axis for the particular (Z, m) state. The orientations with respect to the r-axis and the y-axis are not determined, and so this picture represents a planar slice through three-dimensional space such that the sHce includes the z-axis and is perpendicular to the x-y plane. The angle between this planar slice and the r-axis or the y-axis, though, is arbitrary. 

Fig. 1.21 Echo Planar Imaging (EPI) pulse sequence. Gradient-echo based multiple echoes are used for fast single-shot 2D imaging. Slice selection along Gs and frequency encoding along C, are utilized. Phase encoding is realized using short blipped gradient pulses along Gp.

Y. Lee, J. Yang, S.M. Rudich, R.J. Schreiner, and M.E. Meyerhoff, Improved planar amperometric nitric oxide sensor based on platinized platinum anode. 2. Direct real-time measurement of NO generated from porcine kidney slices in the presence of L-arginine, L-arginine polymers, and protamine. Anal. Chem. 76,545-551 (2004). 

FIGURE 14.3 Pulse sequence for echo-planar imaging. Slice selection is carried out as in Fig. 14.2. The readout gradient Gy is rapidly switched in direction in synchrony with application of a pulsed phase-encode gradient G as indicated. Data are acquired while Gy is turned on but Gx is off. 

There have been numerous other earlier attempts to extract more detailed representations of the pair distribution function from computer simulations. These include calculations of radial functions along vectors (directions) away from the molecule [15], the accumulation of two-dimensional slices of the local density around a molecule [16], and the projection of the full three-dimensional structure onto a two-dimensional (planar) representation [17,18]. These approaches have had some success in providing more detailed structural information and often appeared to represent necessary compromises required by limiting (at that time) computational resources. 

Instead of a cylindrically shaped detector, one can take only a slice of the monocrystal. This will make a planar Ge detector. With a beryllium entrance window, it can be used for X-rays. The last addition to the world of Ge detectors is the Low Energy Germanium detector. If made by Canberra, it will be called LEGE. It is excellent for low energy gamma-rays its energy range extends from 10 to 300 keV. This is indicated in Fig. 5.32. 

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