Irradiation processing variables

Emission Models. Incident models do not make use of all the operating variables, such as radiant power or radiant exitance, diameter, and length of the light source, or dimensions and reflection coefficient of the elliptical cavity mentioned above. Models that describe the space of irradiation on the basis of geometry and process variables are known as emission models. 

Variables associated with several aspects of the processing chain from primary production through irradiation processing and storage conditions to consumption have been examined using mainly chicken bone. 

The effects of seven processing variables which, on the basis of previous literature reports (7, 27) and our chemical studies on model systems, might affect the irradiation flavor intensity or consumer acceptance of irradiated steaks were evaluated in statistically designed and analyzed experiments. Steaks were then prepared using the processing conditions shown to be optimum by these experiments and evaluated for consumer acceptance and storage stability. 

Table IV. Mean Irradiation Flavor Intensity Scores of Enzyme-Inactivated Beefsteaks after Irradiation at 6.0 Megarads in Initial Process Variable Screening Experiment...

The results of the process variable study reported above, along with our previous study (31) of steak preparation variables, lead us to recommend the processing conditions in Table IX for preparing shelf-stable beefsteaks of maximum acceptability. The processing variables having the greatest effects on irradiation flavor intensity and organoleptic acceptability are... 

An extensive testing program has been Initiated to detenplne the burst strength, stress-rupture strength, and susceptibility to crack propagation of the process tube under conditions of elevated tenq rature and variable hydride concentration. Initially, these tests are made using samples of actual process tube under biaxial stress. These tests will provide the bases for comparison with similar tests made on samples of Irradiated process... 

The choice of the strain of microorganism is one of the important variables in the process. The strains to be used in manufacture are mutants of the original producer, which are chosen as the result of a planned program of mutant selection. Sometimes a spontaneous mutation occurs usually, it is induced by mutagenic agents or irradiation of various sorts. The choice of the best strain depends on its abiUty to produce large amounts of the proper antibiotic in a reasonable time from ingredients that are economically feasible (73). 

The classical analysis of the s-process assumes a simple chain starting from 56Fe as the seed. The independent variable is the neutron irradiation , exposure or fiuence ... 

In principle, the approach outlined above for the a-oxoamides can be applied to any reaction, ground or excited state, which converts an achiral reactant into a chiral product, and Toda, Tanaka, and coworkers have investigated a wide variety of such processes [ 15,16]. A complete discussion of their work is beyond the scope of this review, and we illustrate the general approach taken with one final example. As shown in Scheme 4, irradiation of crystalline complexes of ene-diones 20a-f with chiral host (R,R)-(-)-9b led to cyclized products 21a-f in the variable yields and ee values indicated in Table 1 [22]. Remarkably, for reasons that were not clear (there was no accompanying X-ray crystallography), the R=n-propyl derivative 20g was found to give a completely different photoproduct, spiro compound 22 (69% yield, 97% ee, stereochemistry unknown), a result that once again illustrates the rather capricious nature of the use of chiral hosts for asymmetric induction. 

Both partial photolysis by PAR of DOC accompanied by the generation of volatile fatty acids and complete photolysis accompanied by the generation of large quantities of C02 are important findings because of the much lower extinction rates of PAR in water in comparison to those of ultraviolet irradiance. Photolytic processes, so important to nutrient cycling, are therefore not restricted to the uppermost strata of a few centimeters of aquatic ecosystems, but rather affect much of the variable volume of the photic zone. 

---