Energy yield, factors affecting

Thomas, P. C. 1980. Influence of nutrition on the yield and content of protein in milk Dietary protein and energy supply. In Factors Affecting the Yields and Content of... 

By assuming a reactor model, it is possible to determine reaction rates from experimental results. Then, various factors affecting yields, selectivities and reaction rates become evident. Experimental rate laws are deduced from results, e.g. in the classical form involving reaction orders and activation energies. At this stage, computers are used for solving numerically the mathematical models of reaction and reactor (Sect. 4) and for making a statistical analysis of experimental results (Sect. 5). 

So far, much research has gone into finding new synthetic routes, new products and novel selective syntheses, and in the analysis of important factors affecting yield and in some cases selectivity. However, other practical constraints relevant to process development for industrial-scale synthesis have to be tackled. For example, new insights are needed to develop cost-effective, stable, and selective PT catalysts (especially effective immobilized triphase catalysts). Other relevant factors include the recovery and recycle of the PT catalyst, catalyst decomposition, environmental issues such as catalyst toxicity, and ease of product recovery. Catalyst costs are not very high when quats are used, as against the more expensive crown ethers or cryptands. In most cases, the overall process is more than cost-effective since PTC allows the use of cheap alternative raw materials, prevents the use of costly dipolar solvents, is less energy intensive (due to lower temperatures) than alternative methods, alleviates the need... 

Hydrophilic liquids can also cause stabilization and amplification of fluorescence Thus, Dunphy et al employed water or ethanol vapor to intensify the emissions of their chromatograms after treatment with 2, 7 dichlorofluorescein [260] Some groups of workers have pointed out that the layer matenal itself can affect the yield of fluorescent energy [261 —263] Thus, polyamide and cellulose layers were employed m addition to silica gel ones [245] The fluorescence yield was generally increased by a factor of 5 to 10 [264], but the increase can reach 100-fold [234, 265]... 

The temperature dependence of luminescent metal complexes can be controlled by molecular design that affects the energy gap between the emitting state and the deactivating d-d or by altering the preexponential factor for thermal deactivation. The sometimes large temperature dependencies of lifetime and quantum yields for metal complexes also suggest their use as temperature sensors. 

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