Morphology invariance

Nuclear pore complexes (see Chapter 1, Fig. 1) are morphologically invariant throughout both plant and animal kingdoms. Current results suggest that they regulate both import of specific proteins from cytoplasm to nucleoplasm and export of specific RNA molecules from nucleoplasm to cytoplasm. The structure and function of nuclear pore complexes are considered elsewhere in this volume. 

Figure Bl.9.13. Time-resolved SAXS profiles diirmg isothennal crystallization (230 °C) of PET (the first 48 scans were collected with 5 seconds scan time, the last 52 scans were collected with 30 seconds scan time) calculated correlation fiinctions j(r) (nonnalized by the invariant 0 and lamellar morphological variables...

An analysis of partition coefficient data and drug solubilities in PCL and silicone rubber has been used to show how the relative permeabilities in PCL vary with the lipophilicity of the drug (58,59). The permeabilities of copolymers of e-caprolactone and dl-lactic acid have also been measured and found to be relatively invariant for compositions up to 50% lactic acid (67). The permeability then decreases rapidly to that of the homopolymer of dl-lactic acid, which is 10 times smaller than the value of PCL. These results have been discussed in terms of the polymer morphologies. 

The molecular characterization of a polymeric material is a crucial step in elucidating the relationship between its properties (e.g., mechanical, thermal), its chemical structure, and its morphology. As a matter of fact, the development of a new product stems invariably from a good knowledge of the above relationships. Characterization of polymers is often a difficult task because polymers display a variety of architectures, including linear, cyclic, and branched chains, dendrimers, and star polymers with different numbers of arms. 

Metals such as aluminium, steel, and titanium are the primary adherends used for adhesively bonded structure. They are never bonded directly to a polymeric adhesive, however. A protective oxide, either naturally occurring or created on the metal surface either through a chemical etching or anodization technique is provided for corrosion protection. The resultant oxide has a morphology distinct from the bulk and a surface chemistry dependent on the conditions used to form the oxide 39). Studies on various aluminum alloy compositions show that while the oxide composition is invariant with bulk composition, the oxide surface contains chemical species that are characteristic of the base alloy and the anodization bath40 42). 

Figure 7-5. Explanation of morphological stability of the invariant boundaries (interfaces) of AO during the oxidation process, j">j, i = A r,e. ...

Martensitic transformations involve a shape deformation that is an invariant-plane strain (simple shear plus a strain normal to the plane of shear). The elastic coherency-strain energy associated with the shape change is often minimized if the martensite forms as thin plates lying in the plane of shear. Such a morphology can be approximated by an oblate spheroid with semiaxes (r, r, c), with r c. The volume V and surface area S for an oblate spheroid are given by the relations... 

The cestodes are a large and diverse group of platyhelminths that share two common features as adults, they have an elongate body and they lack an alimentary canal. Consequently, they must reside in an elongate, nutrient-rich environment. Thus, adult tapeworms are almost invariably found in the definitive hosts intestine where they absorb nutrients directly across their tegument. The cestode life cycle, with the notable exception of Hymenolepis nana (Fig. 9.1), is indirect and involves at least one intermediate host. Unlike adult tapeworms, the juvenile forms are morphologically quite diverse and can be found in almost... 

In order to do this the points of the image have to be incorporated into the analysis in the form of invariant descriptors. The interpretation of the textural morphology features depends upon the physics of the situation (for example, the gray level may be related to altitude or in another case to the chemical analysis from point to point. The interpretation also depends upon the mathematical relationships between the various morphological descriptors used. There are three major types of morphological texture descriptors. These are statistical terms, symmetry operations, and Invariant texture morphology descriptors (ITMD s). 

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