Second-type links

The larger amount of first-type links provides for the high glassing temperature (285 °C) of the polymer. The presence of second-type links allows one to reprocess this thermoplast with help of pressing, extrusion and die casting on special equipment [152]. 

The company ICI (Great Britain) produced polysulfones identical to Astrel-360 in its chemical structure. However, the polymer 720 P of that firm contains greater number of second-type links. Due to this, the glassing temperature of the polymer is 250 °C and its reprocessing can be done on standard equipment [153]. 

The second type of investigation is the linkage study or genome scan in which there is no predetermined biological hypothesis for the genetic basis of the phenotype. This type of study measures the degree to which the trait is linked to markers which are placed randomly across the whole genome. These studies are discussed further in Section 22.3. 

A second type of protein cross-link has been proposed to occur between a secondary amine and a carbonyl compound through the Mannich reaction20... 

Two types of dopamine receptors have been characterized in the mammalian brain, termed and D2. This subtyping largely arose in response to the finding that while all types of clinically useful neuroleptics inhibit dopaminergic transmission in the brain, there is a poor correlation between reduction in adenylate cyclase activity, believed to be the second messenger linked to dopamine receptors, and the clinical potency of the drugs. This was particularly true for the butyrophenone series (e.g. haloperidol) which are known to be potent neuroleptics and yet are relatively poor at inhibiting adenylate cyclase. 

In the early 1930 s, a second type of resin prepared from formaldehyde was introduced to the market—namely, urea-formaldehyde resins. A few years later, melamine-formaldehyde resins also appeared. The same basic process is employed in polymerization of all these resins it consists of the catalyzed reaction of formaldehyde with the second ingredient—phenol, urea, or melamine—to evolve water and produce three-dimensional, cross-linked thermosetting polymers. 

Two different RO membrane types were evaluated in this study. The first was a standard cellulose acetate based asymmetric membrane. The second type, a proprietary cross-linked polyamine thin-film composite membrane supported on polysulfone backing, was selected to represent potentially improved (especially for organic rejection) membranes. Manufacturer specifications for these membranes are provided in Table III. Important considerations in the selection of both membranes were commercial availability, high rejection (sodium chloride), and purported tolerance for levels of chlorine typically found in drinking water supplies. Other membrane types having excellent potential for organic recovery were not evaluated either because they were not commercially... 

Figures 49B and 50B give the proton resonances of (a+CNP)A(aP)cXL and (ap+CN)A(aP)cXL in H20 in both deoxy and CO forms over the spectral region from +7 to +11 ppm from H20. There are three different types of proton resonances shown in these two figures. The hfs proton resonances due to the cyanomet chains, such as resonances at +10.5 and +9.7 ppm in Fig. 49B, come from the a+CN chain. The second type is due to the hfs proton resonances of the ferrous chains. As discussed earlier, these resonances are too broad to be detectable under our NMR measurement conditions. The third type is due to the exchangeable proton resonances. In going from the deoxy to the CO form (Figs. 49B and 50B), the most obvious change is the disappearance of the resonance at about + 9.2 ppm. It should be noted that the intensity of the resonance at about + 9.2 ppm in both (a+CNP)A(aP)cXL and (aP+CN)A(aP)cXL appears to be approximately 50% that of the resonance at about + 9.3 ppm in deoxy-Hb A or cross-linked Hb A (Miura and Ho, 1982).

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