8-Parameter Sustainable Growth

Figure 8.19. DuPont s 8-Parameter Sustainable Growth Self-Assessment.

We have now seen how local stability analysis can give us useful information about any given state in terms of the experimental conditions (i.e. in terms of the parameters p and ku for the present isothermal autocatalytic model). The methods are powerful and for low-dimensional systems their application is not difficult. In particular we can recognize the range of conditions over which damped oscillatory behaviour or even sustained oscillations might be observed. The Hopf bifurcation condition, in terms of the eigenvalues k2 and k2, enabled us to locate the onset or death of oscillatory behaviour. Some comments have been made about the stability and growth of the oscillations, but the details of this part of the analysis will have to wait until the next chapter. 

In the static crack growth experiments reported in this chapter, the time period for the application of the sustained load (before the interruption of the test for crack observations) was also typically smaller than the transition time, tT. This permits the stress intensity factor K to be used as a characterizing parameter for static crack growth. 

The pH of a system determines the reactions that define the concentration of many dissolved chemical species in water containing salts and minerals, supplied by weathering reactions, rain, runoff, and lixiviating processes. The pH is a key parameter for biological growth and for the sustainment of life for the different aquatic flora and fauna species. As discussed in Chapter 2 the contribution of the different species will affect the final pH and vice versa (i.e., the pH on its own often determines the form of the species present). That is why the distribution diagrams of chemical species are frequently defined as functions of pH (Section 2.1.2). In summary, the main environmental processes that affect the pH and the alkalinity of natural waters include ... 

On one hand, Responsible Care is seen as compliance focused and, while considered a component of sustainability, does not currently offer the platform for embracing all of the concepts of sustainability (focus groups above Sustain Ability, 2004). Responsible Care is viewed as a sector-specific collaborative initiative, whereas sustainability broadly encompasses issues of competitive positioning and business growth, which involve full engagement of internal and external stakeholders. Even as Responsible Care expands focus to include more sustainability parameters, it is not (seen as) sufficient to drive an overall sustainability program, performance, and the business value derived from sustainable development (Savitz, Chapter 8, Section 8.2). 

Second, the model does not predict the growth response to fertilization above levels required to compensate for nutrients removed in the harvested material. The parameters for wood and leaf growth are currently put into the nutrient balance model from the growth model as independent parameters. Growth is only indirectly related to the nutrient balance through the use of land class productivity data in the growth model for the prediction of biomass production. Any fertilization necessary to raise the fertility of the site to a level required to sustain a desired amount of productivity would be included in the transition period costs. The necessary detailed data required to estimate optimum fertilizer schemes are not presently available. 

As the system goes off resonance, the contribution from long-range interactions rapidly diminishes, since the corresponding Massey parameter growths faster than that for short-range interactions. Hence the role of simultaneous vibrational-rotational transitions in the sustaining of resonant conditions increases. 

Silk-keratin blends were used in an abdominal wall musculo-fascial defect model in guinea pigs (Gobin et al., 2006). The blended materials sustained deposition of new extracellular matrix, uniform vascularization and cellular infiltration. Moreover, the mechanical parameters at the repair site were comparable to that of the native tissue. In a separate study, porous scaffolds prepared by blending hyal-uronan and silk were evaluated in a 3-week in vitro culture of human mesenchymal stem cells (Garcia-Fuentes et al., 2009). Histological evaluation of the constructs showed enhanced cellular in-growth into silk fibroin/hyaluronan scaffolds when compared to plain silk fibroin scaffolds. Moreover, in the... 

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