Positive energy balance

Savings in energy costs biogas production makes positive energy balance... 

Specific caloric goals include adequate energy intake to promote growth and development in children, energy equilibrium and preservation of fat stores in well-nourished adults, and positive energy balance in malnourished patients with depleted fat stores. 

The prototype industrial process based on this concept is the Ruhrchemie-Rhone Poulenc process for the hydroformylation of propylene to butanal94,219,220 (see Section 7.3.1). Because of the use of appropriately modified water-soluble ligands, the catalyst resides and operates in the aqueous phase. The particular features of this process are the positive energy balance and easy catalyst recovery, namely, the simply circulation of the aqueous catalyst solution. New types of water-soluble Ir and Rh complexes with tris(hydroxymethyl)phosphine222 were described, and the biphasic hydroformylation of 1-hexene was accomplished in ionic liquids.223 A cationic sugar-substituted Rh complex displays high regioselectivity to branched aldehydes.224... 

In order to achieve an overall positive energy balance the D-T plasma has to be heated to the ignition temperature of 5 keV and confined for a sufficiently long time4). Energy breakeven is usually expressed in terms of the Lawson criterion which states that the product of the plasma density, n, and the energy confinement time re has to exceed a critical value which is a function of the plasma temperature4 8). 

Positive energy balance produces increases in body weight, body fat, or both. Weight loss occurs when expenditure exceeds intake. While the energy balance relationship is clear, application of the concept has not proven to be straightforward or easy. 

Ladisch, Michael R. and Karen Dyck. "Dehydration of Ethanol New Approach Gives Positive Energy Balance," Science, vol. 205, no. 4409, August 1979, pp. 898-900. 

This reaction, which is highly favored thermodynamically, brings glycolysis into positive energy balance because two ATP bonds are made—one from each of the 3-carbon units from glucose. 

After a brief introduction to the nuclear physics of fusion (reaction types, cross sections, reaction rates), it is shown first that sustained nuclear fusion reactions with positive energy balance must also be thermonuclear, i.e., they should take place in a thermal medium. To be precise, the thermal medium where sustained fusion can and should take place is a special medium called high temperature plasma. 

As has already been pointed out in the Introduction, self-sustained fusion reactions with positive energy balance must happen in a thermal medium. This statement can be justified by comparing the effective cross section of individual Coulomb scattering to the fusion cross section. 

A simple expression for the requirements for positive energy balance shall be derived below by assuming homogenous plasma with volume V. The volumetric rate (number per volume per time) of fusion reactions is... 

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