Available energy

Helmholtz free energy The maximum amount of energy available to do work resulting from changes in a system at constant volume. See free energy and Gibbs-Helmholtz equation. 

The metal is a source of nuclear power. There is probably more energy available for use from thorium in the minerals of the earth s crust than from both uranium and fossil fuels. Any sizable demand from thorium as a nuclear fuel is still several years in the future. Work has been done in developing thorium cycle converter-reactor systems. Several prototypes, including the HTGR (high-temperature gas-cooled reactor) and MSRE (molten salt converter reactor experiment), have operated. While the HTGR reactors are efficient, they are not expected to become important commercially for many years because of certain operating difficulties. 

Recall that free energy is the energy available to do work By focusing on free energy we concern ourselves more directly with what is impor tant to a living organism... 

Gross heating value of biomass or methane. Conversion of biomass or methane to another biofuel requires that the process conversion efficiency be used to reduce the potential energy available. These figures do not include additional biomass from dedicated energy plantations. 

Fig. 3. Effect of feed moisture content on energy available for synfuel production. Assumes feed has a heating value of 11.63 MJ /kg (5000 Btu/lb) dry. A, 0% moisture in dried feed B, 30% moisture in dried feed. For example, reduction of an initial moisture content of 70 wt % by thermal drying to 30% moisture content requites the equivalent of 37% feed energy content and leaves 63% feed energy available for SNG production.

The extremely high peak power densities available ia particle beams and lasers can heat the small amounts of matter ia the fuel capsules to the temperatures required for fusion. In order to attain such temperatures, however, the mass of the fuel capsules must be kept quite low. As a result, the capsules are quite small. Typical dimensions are less than 1 mm. Fuel capsules ia reactors could be larger (up to 1 cm) because of the iacreased driver energies available. 

Rates of production of lignite have continued to increase since 1960. In 1980 374 x 10 tons of coal equivalent (tee) were produced. One tee is the amount of energy available from combustion of a metric ton of coal having a heat content of 29.3 GJ, ie, 29.3 MJ/kg (12, 600 Btu/lb) (3). In 1989 this figure had risen to 460 x 10 tee. This 23% increase is somewhat less than the 28% increase in hard coal production during this period (see Coal). In 1990 the 1130 X 10 metric tons of lignite produced worldwide represented 24% of the total coal production. 

Chemistry. The material and energy available in plasmas can be used to excite materials and drive chemical reactions. The unique characteristics of plasmas, especially thek abundance of energetic species, have been exploited in plasma chemical apphcations (79—84). 

Because AG is the net useflil energy available from a given reaction, in electrical terms, the net available electrical energy from a reaction is given by... 

B. Stanmore, D. N. Boria, and L. E. Paulson, Steam Dying of Eignite A Beview of Processes and Peformance, DOE/GEETC/Rl-82/1 (DE82007849), U.S. Department of Energy, available from National Technical Information Service, Washington, D.C., 1982. 

E Explosion energy available to generate blast and fragment kinetic... 

Inert, Ideal Gas-Filled Vessels The energy available for external work following the rapid disintegration of the vessel is calcuJated by assuming that the gas within the vessel expands adiabatically to atmospheric pressure. 

Figure 27-43 shows the amount of energy available for power by using a fire-tube boiler, an industrial bofler, and subcridcal- and supercritical-pressure boilers. Condensing losses decrease substantially, and regeneration of air and feedwater becomes increasingly important in the most advanced central-station boilers. 

The energy available in the steam is expressed in British thermal units per pound, or enthalpy. The velocity of the steam flow through the nozde is calculated from... 

A common solution that allows one to overcome the limited sampling by MD simulations at room temperature is simply to raise the temperature of the simulation. The additional kinetic energy available in a higher temperature simulation makes crossing high... 

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