Materials pool

The use of wood in long-life products, such as buildings, ensures that this sequestered carbon is held in a materials pool for a longer time. If the use of renewables is encouraged, then more carbon is stored in this manner. Eventually, of course, such systems will establish equilibrium with the environment, as the materials flow into the pool equals the materials flow out into the environment. The use of wood in this way intervenes in a natural cycle, so that wood use and ultimate disposal replaces the natural cycle of wood decay in the forest (Figure 1.5). 

Figure 1.5 The use of wood products stores carbon in a materials pool, eventual disposal returning the sequestered carbon to the grand carbon cycle to provide for growth of new forest.

If the forest resource is properly managed, then timber can be harvested indefinitely. The use of timber in products represents a means by which atmospheric carbon can be stored in materials pools. 

Extending the life of timber products will result in carbon being stored in a materials pool for longer periods. 

Examples of possible uses of biological materials (pooled collections of scrum, urine, etc.) as standards are in methods for estimating total protein concentration in serum, for measuring enzyme activities in serum and other body fluids, and for determining urinary steroids and their metabolites. The special requirements of multichannel analysis will be considered separately (Section 3.1.1.3), and the reasons why these three different investigations can perhaps best be standardized in relation to biological materials will now be discussed. 

The first one is filled with the whole of the mixture to be studied (e.g., serum), the other with the isolated material (pooled fractions) from a preceding separation step. The plate is left for diffusion to proceed. At this stage diffusion causes the contents of both wells to mix and after immunoelectrophoresis a double peak of the particular antigen appears. 

For some free-flowing sample materials, Poole has considered an example where the values of G are given as follows ... 

Daily and before each use the hood should be checked to ensure that material is not blocking the hood opening or exhaust ports. This housekeeping procedure should also include checking the fume hood to ensure that there are no puddles of spilled materials pooled within. 

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