Calculations Of Energy And Ecoexergybased Ascendency

The four networks in steady state that were used in J0rgensen et al. (2000) to illustrate the three growth forms (see also J0rgensen, 2002 J0rgensen and Svirezhev, 2004 Fath et al., 2004) have been applied here to calculate the eco-exergy storage and eco-exergy ascendency and compared with the previous energy-based ascendency. The below shown calculations are based on J0rgensen and Ulanowicz (submitted). Figure 14.3 shows a four-component network that has only cycling of the energy. The network...

The Evolutionary Development Of The Biodiversity

Biodiversity may cover several diversity concepts as, for instance, the number of species, the number of families, the genetic diversity, Shannon's index, which may be considered just a logarithmic expression for the species diversity, the landscape diversity expressed by the number of biotic and abiotic constituents in the landscape and the number of Figure 13.1 The results of the experiments in grassland by Tilman and Downing (1994). The higher the number of species, the higher the drought...

Formation Of Polymer Organic Molecules

The fuel of ecosystems is organic matter, detritus. It is therefore relevant to calculate the free energy of dead organic matter, consisting of poly-organic molecules. The chemical potential of dead organic matter, indexed i 1, can be expressed from classical thermodynamics (e.g., Russel and Adebiyi, 1993) as where mi is the chemical potential. The difference mi - is known for detritus organic matter, which is a mixture of carbohydrates, fats and proteins. Approximately 18.7 kJ g may be applied...

What Is Exergy

Previously in this chapter, we have used the term work capacity'' to express the ability of a part of the total energy to perform work in contrast to the heat energy at the temperature of the environment, that is without work capacity. The classical thermodynamics is using the G-function to cover the work capacity but when we are dealing with very far from thermodynamic systems, we cannot any longer use state variables that are independent of the pathway. Furthermore, we need in different...

Le Chateliers Principle

The exergy-storage hypothesis might be taken as a generalized version of ''Le Chatelier's Principle''. Biomass synthesis can be expressed as a chemical reaction energy + nutrients molecules with more free energy (exergy) and organization + dissipated energy. According to Le Chatelier's Principle, if energy is put into a reaction system at equilibrium, the system will shift its equilibrium composition in a way to counteract the change. This means that more molecules with more free energy and...

The Three Growth Forms Applied On Aquatic Ecosystems

Figure 12.1 illustrates how the three growth forms interact according to Figures 1.4 and 1.5 in Section 1.11. Growth form I is dominant in the first phase of the development from an early stage ecosystem to a mature ecosystem. By increasing the biomass, the solar radiation captured increases up to about 75 , corresponding to what is physically possible. Growth forms II and III are dominant in the intermediate phase and when the ecosystem is in a mature stage. Thereby more exergy is stored...

How To Calculate Exergy Of Organic Matter And Organisms

The following expression for the exergy per unit of volume has been presented see Equation 1.17 Ex RT ci ln ci cio ML 1T 2 1.22 where R is the gas constant, T is the temperature of the environment, while ci is the concentration of the ith component expressed in a suitable unit, for example for phyto-plankton in a lake c, could be expressed as mg l or as mg l of a focal nutrient. cio is the concentration of the ith component at thermodynamic equilibrium and n is the number of components. cio is...