Primary shaping

The underground rhizome consists of two distinct parts the egg-shaped primary or mother rhizome, which is an extension of the stem, and the long cylindrical, multibranched secondary rhizomes, growing downward from the primary rhizomes. Rhizomes are of orange-brown, pale yellow or reddish-yellow in colour. 

Pig. 212.—Cross section through root-bark of Euonymus atropurpureus. Note the two broad dome-shaped phloem patches, one on either side of a wedge-shaped primary medullary ray. 

Arc black consists of platelet-shaped primary particles as with acetylene black. 

The easiest way to produse a collimated beam is to combine two narrow pinhole diaphragms in a line. For reasons of intensity, however, line-shaped primary beams... 

Moided secondary components, substitution for metal castings, electrical housings, and parts. Complex electrical components, leading and trailing edges, and highly loaded complex shapes. Primary and secondary structure for subsonic aircraft, ducts, housings, bulkheads, intake manifolds, helicopter blades, radomes, etc. (Probably the most versatile material)... 

BO-TO C needle-shaped primary particles, aggregated into 80 nm cubic clusters [46]. Data on particle characteristics not provided [46]. 

The first report of microemulsion-mediated synthesis of an iron oxide phase was by Inouye et al. [46]. The microemulsion-plus-reactant method (C of Fig. 3) was used by bubbling molecular oxygen into a ferrous ion-containing microemulsion. Microemulsions based on either AOT (i.e., AOT/hydrocarbon/water, where the hydrocarbons were cyclohexane, hexane, or heptane) or potassium oleate (i.e., potassium oleate/ -hexane///-hexanol/water) were used the aqueous pseudophase consisted of a ferrous ammonium sulfate solution (5x10 and 10 M). Electron microscopy revealed needle-shaped primary particles that aggregated into cubic clusters ( 80 nm). It was concluded from the particle shape and elec-... 

These pictures were taken with a special camera designed for the purpose by Kratky (Cf. Z. Elektrochem., 48 (1942), 409). The black line in the centre of the photographs is caused by the flat ribbon-shaped primary pencil of X-rays and should be disregarded. The low angle scattering is seen at both sides of white patches on the photograph. The ordinary crystalline cellulose interferences are not seen in the picture, since they fall outside the field of vision. 

This equation holds true for arbitrarily shaped primary particles, which may be compact individuals (as considered by Rumpf) or aggregates of even finer particles (Baldyga et al. 2008). The equation can be further refined by considering the interdependence of porosity e gg and coordination number Nc- Rumpf proposed a... 

The particle morphology of a hard template is inherited by the resultant carbon, as demonstrated in Figure 2.18. The morphologies of SBA-15 and the OMCs are very similar both are made up of bundles of bamboo-shaped primary particles of about 400-nm diameter and 10-pm length [135]. Rodlike SBA-15 silica... 

The interest in vesicles as models for cell biomembranes has led to much work on the interactions within and between lipid layers. The primary contributions to vesicle stability and curvature include those familiar to us already, the electrostatic interactions between charged head groups (Chapter V) and the van der Waals interaction between layers (Chapter VI). An additional force due to thermal fluctuations in membranes produces a steric repulsion between membranes known as the Helfrich or undulation interaction. This force has been quantified by Sackmann and co-workers using reflection interference contrast microscopy to monitor vesicles weakly adhering to a solid substrate [78]. Membrane fluctuation forces may influence the interactions between proteins embedded in them [79]. Finally, in balance with these forces, bending elasticity helps determine shape transitions [80], interactions between inclusions [81], aggregation of membrane junctions [82], and unbinding of pinched membranes [83]. Specific interactions between membrane embedded receptors add an additional complication to biomembrane behavior. These have been stud-... 

Figure B2.5.12 shows the energy-level scheme of the fine structure and hyperfme structure levels of iodine. The corresponding absorption spectrum shows six sharp hyperfme structure transitions. The experimental resolution is sufficient to detennine the Doppler line shape associated with the velocity distribution of the I atoms produced in the reaction. In this way, one can detennine either the temperature in an oven—as shown in Figure B2.5.12 —or the primary translational energy distribution of I atoms produced in photolysis, equation B2.5.35.

The shape of a large protein is influenced by many factors including of course Its primary and secondary structure The disulfide bond shown m Figure 27 18 links Cys 138 of carboxypeptidase A to Cys 161 and contributes to the tertiary structure Car boxypeptidase A contains a Zn " ion which is essential to the catalytic activity of the enzyme and its presence influences the tertiary structure The Zn ion lies near the cen ter of the enzyme where it is coordinated to the imidazole nitrogens of two histidine residues (His 69 His 196) and to the carboxylate side chain of Glu 72... 

Protein tertiary structure is also influenced by the environment In water a globu lar protein usually adopts a shape that places its hydrophobic groups toward the interior with Its polar groups on the surface where they are solvated by water molecules About 65% of the mass of most cells is water and the proteins present m cells are said to be m their native state—the tertiary structure m which they express their biological activ ity When the tertiary structure of a protein is disrupted by adding substances that cause the protein chain to unfold the protein becomes denatured and loses most if not all of Its activity Evidence that supports the view that the tertiary structure is dictated by the primary structure includes experiments m which proteins are denatured and allowed to stand whereupon they are observed to spontaneously readopt their native state confer matron with full recovery of biological activity... 

Both (i) and (ii) necessitate recourse to a model of pore shape. By far the commonest, chosen on grounds of simplicity, is the cylinder but the slit model is being increasingly used where the primary particles are plate-like, and the model where the pore is the cavity between touching spheres is beginning to receive attention. 

The limits of pore size corresponding to each process will, of course, depend both on the pore geometry and the size of the adsorbate molecule. For slit-shaped pores the primary process will be expected to be limited to widths below la, and the secondary to widths between 2a and 5ff. For more complicated shapes such as interstices between small spheres, the equivalent diameter will be somewhat higher, because of the more effective overlap of adsorption fields from neighbouring parts of the pore walls. The tertiary process—the reversible capillary condensation—will not be able to occur at all in slits if the walls are exactly parallel in other pores, this condensation will take place in the region between 5hysteresis loop and in a pore system containing a variety of pore shapes, reversible capillary condensation occurs in such pores as have a suitable shape alongside the irreversible condensation in the main body of pores. 

The three levels of structure listed above are also useful categories for describing nonprotein polymers. Thus details of the microstructure of a chain is a description of the primary structure. The overall shape assumed by an individual molecule as a result of the rotation around individual bonds is the secondary structure. Structures that are locked in by chemical cross-links are tertiary structures. 

Cyclodextrins are macrocyclic compounds comprised of D-glucose bonded through 1,4-a-linkages and produced enzymatically from starch. The greek letter which proceeds the name indicates the number of glucose units incorporated in the CD (eg, a = 6, /5 = 7, 7 = 8, etc). Cyclodextrins are toroidal shaped molecules with a relatively hydrophobic internal cavity (Fig. 6). The exterior is relatively hydrophilic because of the presence of the primary and secondary hydroxyls. The primary C-6 hydroxyls are free to rotate and can partially block the CD cavity from one end. The mouth of the opposite end of the CD cavity is encircled by the C-2 and C-3 secondary hydroxyls. The restricted conformational freedom and orientation of these secondary hydroxyls is thought to be responsible for the chiral recognition inherent in these molecules (77). 

Pig. 6. A 0.3-mm-diameter cosmic spherule coUected from the ocean floor. The particle is composed of oUvine, glass, and magnetite and has a primary element composition similar to chondritic meteorites for nonvolatile elements. The shape is the result of melting and rapid recrystaUi2ation during... 

Filler particle si2e distribution (psd) and shape affect rheology and loading limits of filled compositions and generally are the primary selection criteria. On a theoretical level the influence of particle si2e is understood by contribution to the total energy of a system (2) which can be expressed on a unit volume basis as ... 

A variation to the top-feed dmm filter is the dual dmm filter which uses two dmms of the same size in contact with each other and rotating in opposite directions. The feed enters into the V-shaped space formed on top of the two dmms and the cake that starts forming initially contains coarser particles due to the settling which takes place in the feed zone. This is beneficial to the clarity of the filtrate because the coarser particles act as a precoat. Erom the point of view, however, of the final moisture content of the cake the stratification of the soHds in the cake may lead to somewhat wetter cakes. Utilization of the area of the dmms is poor since there are dead spaces under the two dmms. The primary appHcation of the dual dmm filters is in dewatering coarse mineral or coal suspensions at feed concentrations greater than 200 kg/m. ... 

The relationship between molecular stmcture and sensory properties is very unclear for compounds with odor. It seems likely that there is a set of odors that could be called primaries, but a widely accepted Hst of such primary odor quahties has not been devised. Molecular size and shape have been used to... 

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