Phase gradients

Figure Bl.14.1. Spin warp spin-echo imaging pulse sequence. A spin echo is refocused by a non-selective 180° pulse. A slice is selected perpendicular to the z-direction. To frequency-encode the v-coordinate the echo SE is acquired in the presence of the readout gradient. Phase-encoding of the > -dimension is achieved by incrementmg the gradient pulse G...

Agari, Y, Shimada, M., Ueda, A. and Nagai, S. (1996) Preparation, characterization and properties of gradient polymer blends discussion of poly(vinyl chloride)/poly (methyl methacrylate) blend films containing a wide compositional gradient phase. Macromol. Chem. Phys., 197, 2017-2033. 

In this example, the gradient applied in the y-direction is referred to as the phase encoding gradient. Phase encoding refers to the action of an applied gradient that is responsible for moving the acquisition through the k-space raster. In this case, the... 

Caged peptides (NPY and angiotensin II) containing Tyr[Bzl(2-N02) were synthesized on an automated solid-phase peptide synthesizer using Fmoc chemistry and cleaved from the resin by treatment with TFA. Crude peptides were purified by semipreparative HPLC with a gradient phase of 0.1% TFA and MeCN. For fractions containing peptides, the eluant was not passed through the UV monitor to avoid potential photolysis. The collected peptide was examined by analytical HPLC and MS. 

Here r denotes voxel position, k = In jK where is the length of the mechanical wave in the gel, R is the displacement amplitude of the wave, 0 is the gradient phase offset from the mechanical excitation phase, and n is the number of gradient periods. Clearly, the more oscillation periods enter into the integral, the larger the detectable phase shift or the smaller the detectable sample deformations R. 

The first of these is simply die definition of the gradient, whereas the second is the original ODE expressed in terms of the gradient. Figure 17 shows the concentration—gradient phase plane, in which the trajectory corresponds to the concentration profile of the front. The trajectory connects two stationary states, the state (a, u) = (0, 0) at z - > and the state (a, ) = (1, 0) at z... 

Figure 3.71 shows the change of average polystyrene phase diameter versus distance along the radial direction. The gradient phase structure was intensely related to the polystyrene content. With increasing amount of polystyrene, the size of the dispersed phase in the fiber center decreased continuously to nanosized fibrillar structure [257]. 

In the absence of the temperature gradient phase-lag xt = 0), the nonequUibrium entropy production 5 under the effect of the classical h5q)erbolic heat conduction model becomes ... 

Speed change feeding Accelerated rate in the fermentation process (gradient, phase, linearity, etc.), specific growth rate is constantly changing... 

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