Indirect balancing

If n is the number of measurements (e.g. yield) and m the number of constraints (balances applicable), then the degree of freedom of the system is m - n.li m n, one cumulated mole number or one yield can be estimated from the other if it is was not measured or if it is erroneous. 

For example, Okabe et al. (1992) [52] report the following growth stoichiometry for the sulfate reducing bacteria Desulfovibrio desulfur icons growing on lactic acid and sulfate, and producing biomass, acetic acid, CO2 and H2S. 

Sulfur recovery Rs = 0.73 (assuming an atomic coefficient in biomass Xs = 0.0044 as for M thermoautotrophicum). 

It is clear that the available electrons and the sulfur balances are not correct, whereas the carbon balance is very satisfactory. In fact, biomass is negligible in these calculations and it is difficult to estimate accurately H2S produced during the experiment. Thus, the yield KnjS/iii.ac can be estimated by solving the available electron balance  

The specific growth rate may be calculated from the biomass production rate as follows  

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Figure 15 Variation of the specific growth rate and the biomass yield on glucose during cell cycle oscillations. Biomass formation rate was estimated by indirect balancing using the enthalpy balance. (Redrawn from Reference [53] with permission of the author and publisher).

The well-known DLVO theory of coUoid stabiUty (10) attributes the state of flocculation to the balance between the van der Waals attractive forces and the repulsive electric double-layer forces at the Hquid—soHd interface. The potential at the double layer, called the zeta potential, is measured indirectly by electrophoretic mobiUty or streaming potential. The bridging flocculation by which polymer molecules are adsorbed on more than one particle results from charge effects, van der Waals forces, or hydrogen bonding (see Colloids). 

Thus the amount of heat that must be produced by burning coke ia the regenerator is set by the heat balance requirements and not directly set by the coke-making tendencies of the catalyst used ia the catalytic cracker or by the coking tendencies of the feed. Indirectly, these tendencies may cause the cracker operator to change some of the heat-balance elements, such as the amount of heat removed by a catalyst cooler or the amount put iato the system with the feed, which would then change the amount of heat needed from coke burning. 

Fig. 4. Column sequences and material balance lines for the (a) direct and (b) indirect sequences for separating nonazeotropic...

To estimate the current yield of magnesium alloys, the weight loss is determined indirectly over the volumetric measurement of the evolved hydrogen in the apparatus in Fig. 6-9 in Section 6.2.4. The mass balance for oxygen-free media follows from Eqs. (6-1) and (6-5a,b) or (6-14) ... 

Bojnowski, J. J., Groghan, R. M., Jr., and Hoffman, R. M., Direct and Indirect Material Balance Control, Chemical Engineering Progress, September 1976. 

One of the critical measurements is torque or shaft power. A variety of methods is recognized direct methods such as torque meters or reaction mounted drivers (dynamometers) and indirect methods such as electrical power input to drive motors, heat balance, or heat input to a loop cooler. See Part 7, Measurement of Shaft Power, PTC 19.7 1961 [3] for additional information. 

If the instruments are in, the meter run was available, and gas composi-tion can be accurately determined as needed, one last minor hurdle should be addressed. This is power measurement. The indirect method, such as heat balance can be used. In fact, it should be used as a redundant method. 

In the unit, the heat of reaction is a useful tool. It is an indirect indication of heat balance accuracy. Trending the heat of reaction on a regular basis provides insight into reactions occurring in the riser and the effects of feedstock and catalyst changes. 

Where a flooded coil is located in a liquid tank, the refrigerant level will be within the tank, making it difficult to position the level control. In such cases, a gas trap or siphon can be formed in the lower balance pipe to give an indirect level in the float chamber. Siphons or traps can also be arranged to contain a non-voIatile fluid such as oil, so that the balance pipes remain free from frost. 

The answer in practice is ATP though you would have been theoretically correct if you had said ADP and AMP. Indirectly, NAD+ or NADH are also compounds which regulate the anabolic/catabolic balance. 

PTH has a dual effect on bone cells, depending on the temporal mode of administration given intermittently, PTH stimulates osteoblast activity and leads to substantial increases in bone density. In contrast, when given (or secreted) continuously, PTH stimulates osteoclast-mediated bone resorption and suppresses osteoblast activity. Further to its direct effects on bone cells, PTH also enhances renal calcium re-absorption and phosphate clearance, as well as renal synthesis of 1,25-dihydroxy vitamin D. Both PTH and 1,25-dihydroxyvitamin D act synergistically on bone to increase serum calcium levels and are closely involved in the regulation of the calcium/phosphate balance. The anabolic effects of PTH on osteoblasts are probably both direct and indirect via growth factors such as IGF-1 and TGF 3. The multiple signal transduction... 

Hypothermia—Indirect cryodestruction Metabolic uncoupling Energy deprivation Ionic imbalance Disruption of acid-base balance Waste accumulation Membrane phase transitions Cytoskeletal disassembly Frozen State—Direct cryodestruction Water solidification Hyperosmolality Cell-volume disruption Protein denaturation Tissue shearing Intracellular-ice propagation Membrane disruption Microvascular Thawed State Direct effects... 

Three-spin effects arise when the nonequilibrium population of an enhanced spin itself acts to disturb the equilibrium of other spins nearby. For example, in a three-spin system, saturation of spin A alters the population of spin B from its equilibrium value by cross-relaxation with A. This change in turn disturbs the whole balance of relaxation at B, including its cross-relaxation with C, so that its population disturbance is ultimately transmitted also to C. This is the basic mechanism of indirect nOe, or the three-spin effect. 

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