Segment homogeneity

Fig. 4. Effect of (-)-linalool on GFAP expression in the spinal cord of neuropathic mice. GFAP expression was analyzed by western blot in the lumbar spinal cord (L4-L5 segment). Homogenates were from the ipsi(I)- and contra(C)-lateral side of the cord from SNL animals treated either with linalool (100 mg/kg s.c.) or vehicle for 7 days (pool of three animals for each experimental group). Actin was used as loading control.

Problem 3.11 Consider two polymer coils each consisting of 1000 segments homogeneously distributed in their respective spheres. If the segments occupy 1% of the sphere s volume, what is the probability that the two spheres can be superimposed so that all segments find an unoccupied location simultaneously ... 

Two are the patterns of enhancement of a pathologic bowel segment homogeneous and stratified . Homogeneous enhancement is a diffuse transmural enhancement with no recognition of different bowel layers. A stratification of the bowel wall (the so called target or double halo appearance) is related to mucosal enhancement with hypoenhancing outer layer. 

Fig. 7.22. Effect of annealing temperature and constraint during annealing on the strained segment homogeneity n which is defined as the ratio of that strain where the first radicals are observed to the strain at break [271.

Let us consider a thin homogeneous isotropic beam of thickness 2s. We assume that the beam mid-line coincides with the segment (0,1) of the axis X. At the point y = 1/2, the beam has an inclined cut as a segment having the angle a with the vertical line, 0 < tana < 2e). We look for the function % = (W, w) of horizontal displacements W(x) and vertical displacements w(x) provided that the external forces g(x),f(x) are given. The condition of clamped edges... 

Homogeneous nucleation occurs when, as a result of statistically random segmental motion, a few segments have adopted the same conformation as they would have in a crystallite. At one time it was considered that the likelihood of the formation of such nuclei was greatest just above the transition temperature... 

While thin polymer films may be very smooth and homogeneous, the chain conformation may be largely distorted due to the influence of the interfaces. Since the size of the polymer molecules is comparable to the film thickness those effects may play a significant role with ultra-thin polymer films. Several recent theoretical treatments are available [136-144,127,128] based on Monte Carlo [137-141,127, 128], molecular dynamics [142], variable density [143], cooperative motion [144], and bond fluctuation [136] model calculations. The distortion of the chain conformation near the interface, the segment orientation distribution, end distribution etc. are calculated as a function of film thickness and distance from the surface. In the limit of two-dimensional systems chains segregate and specific power laws are predicted [136, 137]. In 2D-blends of polymers a particular microdomain morphology may be expected [139]. Experiments on polymers in this area are presently, however, not available on a molecular level. Indications of order on an... 

In conclusion therefore it may be stated that one must be able to distinguish between motional dispersion and motional homogeneity. Furthermore, a reconstruction of the chemical shift parameters from spectra with MAS at very low temperatures is needed to obtain quantitative motional information. Similar problems to the above also arise in other linear polymers containing interspaced soft and hard segments. 

Three kinds of polymer segments are formed in the polymerization of dienes 1-4 cis-, 1-4 trans-, and 1-2 segments (or 3-4 in polymerization of isoprene or other monosubstituted dienes). The latter may form isotactic or syndiotactic diads when the proportion of the 1-2 form is sufficiently high, e.g. a syndiotactic, highly 1-2 polybutadiene was described recently by Ashitaka et al. 123), although the so far examined 1-2 polybutadienes produced by homogeneous anionic polymerization were found to be atactic (unpubl. results of Bywater, Worsfold). 

In what follows the illustration of this method is concerned with equation (1) from (Section 1) capable of describing the stationary distribution of temperature over a homogeneous bar 0 < a < 1. The equation of the heat balance can be written on the segment ... 

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