Global density range

Global density range (molecular density range). [ag, amjn) ag is defined above, whereas amj is a low threshold value below which electron density can be neglected. The molecule is represented by a single, connected density domain for each threshold value within the global density range. 

Collectively, the atomic and the functional group ranges form the localized range, whereas the molecular density range is the global density range. 

LLDPE made uses 1-hexene as comonomer, approximately 35% uses 1-butene, and approximately 25% uses 1-octene. Only a small fraction is made using 4-methyl-1-pentene. Hexene and butene copolymers are more prevalent because they are less expensive than octene and because they are commonly used in the gas-phase process, which accoimts for most of the global LLDPE production. For LLDPE, density is strongly controlled by comonomer content. Conventional LLDPE basically covers the density range of0.915-0.940. Within that density range, and also lower density ranges, there are common product family subsets. Table 1 shows comonomer content and subsequent density ranges for commercial LLDPE. 

There are two types of data necessary to obtain accurate global estimates of vegetation carbon pools or biomass. First, it is important to have accurate data on the areal extent of major ecosystems. Matthews (29) found that calculations of global biomass were significantly influenced by the land cover data set used. Second, there must be accurate estimates of biomass density for terrestrial ecosystems. There is a wide range of estimates published for the same ecosystem, each derived by different methods (29), and none having statistical reliability (7). 

If the polymer concentration increases so that the number of high order bead-bead interactions is significant, c>>c =p, (when c is expressed as the polymer volume fraction. Op), the fluctuations in the polymer density becomes small, the system can be treated by mean-field theory, and the ideal model is applicable at all distance ranges, independent of the solvent quaUty and concentration. These systems are denoted as concentrated solutions. A similar description appHes to a theta solvent, but in this case, the chains within the blobs remain pseudoideal so that =N (c/c ) and Rg=N, i.e., the global chain size is always in-... 

A three dimensional integration of this density over values of r ranging from 0 to the mean branch extension, Rg (which is also proportional to the global star size Rg), i.e., over the overall chain volume, give the total number of units in the star, N. In this manner the chain mean size is estimated as... 

---