Niche metrics

The state of communities and ecosystems can be described according to both structural and functional parameters (see Chapter 14 in Walker et al. 2000). Functional analyses include the measurement of nutrient cycling, turnover of organic residues, energy flow, and niche metrics. Structural analyses include the assessment of species present, their population densities, and their genetic composition. 

The worldwide cement composition is —1.6 billion metric tons per year [2], approximately 3% of which is consumed by the oil and natural gas industry. Thus, the annual cement consumption by this industry is —48 million metric tons. The industry, till now, has depended on modified portland cement, but there are niche areas where conventional cement is not reliable. Portland cement has several shortcomings for borehole sealant. It does not set easily in permafrost temperatures, because the water in it will freeze even before the cement sets. Its bonding to earth materials in the presence of oily surfaces is poor. Inherently porous, it cannot form a good seal. A major ingredient, calcium oxide, is affected by downhole gases such as carbon dioxide as a result, cement performance can be poor. These problems can be overcome by a range of CBPC formulations because of their above-mentioned superior properties. 

Because polypyrrole operates in aqueous electrolytes at room temperature, the largest niche for conjugated polymer microactuators is biomedical applications. Commercialization efforts are underway for blood vessel coimectors, a valve to prevent urinary incontinence, and a Braille display [25,122,133]. One area that requires further research is the temperature-dependence of actuator metrics, because for biomedical applications the devices must be operated at 37°C. In PPy(DBS) microactuators, strain increases from room temperature to body temperature by 45%, and they are 250% faster, but the blocked force drops [126]. 

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