Trends within

Increa sing the bulkiness of the alkyl group from the esterifying alcohol in the ester also restricts the motion of backbone polymer chains past each other, as evidenced by an increase in the T within a series of isomers. In Table 1, note the increase in T of poly(isopropyl methacrylate) over the / -propyl ester and similar trends within the butyl series. The member of the butyl series with the bulkiest alcohol chain, poly(/-butyl methacrylate), has a T (107°C) almost identical to that of poly(methyl methacrylate) (Tg = 105° C), whereas the butyl isomer with the most flexible alcohol chain, poly( -butyl methaciylate), has a T of 20°C. Further increase in the rigidity and bulk of the side chain increases the T. An example is poly(isobomyl methacrylate)... 

An aimual review of the worldwide catalyst industry identifies current technical and business trends within the catalyst industry and fists virtually aU industrial supported (and other) catalysts by manufacturers designations (3). Included are the applications for the catalysts, the composition, ie, active agents and support materials, and some physical properties. 

Chemical trends within Group 14 are discussed on p. 373. Silicon does not form binary compounds with the heavier members of the group (Ge, Sn, Pb) but its compound with carbon, SiC,... 

The known halides of vanadium, niobium and tantalum, are listed in Table 22.6. These are illustrative of the trends within this group which have already been alluded to. Vanadium(V) is only represented at present by the fluoride, and even vanadium(IV) does not form the iodide, though all the halides of vanadium(III) and vanadium(II) are known. Niobium and tantalum, on the other hand, form all the halides in the high oxidation state, and are in fact unique (apart only from protactinium) in forming pentaiodides. However in the -t-4 state, tantalum fails to form a fluoride and neither metal produces a trifluoride. In still lower oxidation states, niobium and tantalum give a number of (frequently nonstoichiometric) cluster compounds which can be considered to involve fragments of the metal lattice. 

Include multiple water bodies (clusters of sites) within each monitored geographic area. Within a geographic area, the chosen biological indicators should be sampled in several waterbodies of a given type (i.e., clusters of lakes or streams), because data from several sites will probably be needed to identify the overall trend within the area (Section 4.4). The direction of temporal trends can differ among individual water bodies because of spatio-temporal variation in other factors that influence mercury... 

In detail, some of the trends within individual across-arc traverses are complicated. For example, within Kamchatka U/Th ratio increases with depth to the Benioff zone (Turner et al. 1998), although there is no simple correlation with (Fig. 20a). 

In contrast to carbon compounds, force constants and bond distances of SiO and SiOz - as well as of SiS and SiS2 - are equal. On the other hand, the trend within the bond energies shows the expected decrease from SiO to Si02 and from SiS to SiS2, respectively. 

The experimental procedure for conducting phase solubility analysis is rather simple it consists of mixing increasing amounts of sample with a fixed volume of solvent and then determining the mass of sample that has dissolved after each addition. It is not necessary to exceed the solubility limit of the analyte species, but attainment of this condition makes it easier to recognize trend within the plots. An experimental protocol for phase solubility analyses is available [39]. The data are most commonly plotted with the system composition (total mass of sample added per gram solvent) on the x axis, and the solution composition (mass of solute actually dissolved per gram of solvent) on the y axis. 

Structural Trends within Alane and Gallane Adducts... 

The rare earth elements (REE) form a group of elements that have coherent geochemical behaviour due to their trivalent charge and similar ionic radii. They can, however, be fractionated from one another as a result of geochemical processes operating under specific physico-chemical conditions. In order to outline general trends within and differences between the individual REE, concentrations are usually normalized to a reference system (e.g. to shale). Deviations of individual elements from the generally smooth trend are referred to as anomalies. 

The overall relationship between rate and C-H--C(sp2) distance is shown in Fig. 15. Though there are clear irregularities, the general trend, of reactivity increasing with decreasing distance, is clear and unmistakable an increase of 0.25 A in the distance each hydrogen has to move is associated with a decrease of over 104 times in the rate at which it moves. As the authors point out, the reversal of this trend within small groups of... 

Examine general trends within the periodic table. 

Be(OH)2 were the same as that in other compounds, they would all follow the same horizontal trend within error. Figure l-4b shows that ln( Mo) + 0.012977t versus t follows different trend for different compounds, indicating that the decay constant of Be depends on the kind of compound Be is in. The variation of the decay constant amounts to about 1.5%. Tossell (2002) raised doubt about the experimental results based on calculated electron density of Be in various compounds, but the reliability of the theoretical calculation has not been verified. 

The propensity of sulfur, selenium and tellurium to catenate is illustrated by the formation of an extensive series of polyanions for all three chalcogens. The structures of these polyanions exhibit interesting trends within the series in which the ability of tellurium and, to a lesser extent, selenium to adopt... 

---