Secondary disintegration

Secondary Disintegration of Jet Droplet When the jet di tegrates, the iuitial droplet size is given by the above correlation. However, often these initial droplets can be relativd y large and may not be stable. The droplets from the jet can further disintegrate under two conditions. These are... 

Graphite will creep imder neutron irradiation and stress at temperatures where thermal creep is normally negligible. The phenomenon of irradiation creep has been widely studied because of its significance to the operation of graphite moderated fission reactors. Indeed, if irradiation induced stresses in graphite moderators could not relax via radiation creep, rapid core disintegration would result. The observed creep strain has traditionally been separated into a primary reversible component ( ,) and a secondary irreversible component (Ej), both proportional to stress and to the appropriate unirradiated elastic compliance (inverse modulus) [69]. The total irradiation-induced creep strain (ej is thus ... 

The products of nuclear fission reactions are radioactive and disintegrate according to their own time scales. Often disintegration leads to other radioactive products. A few of these secondary products emit neutrons that add to the pool of neutrons produced by nuclear fission. Very importantly, neutrons from nuclear fission occur before those from radioactive decay. The neutrons from nuclear fission are termed prompt. Those from radioacth e decay arc termed delayed. A nuclear bomb must function on only prompt neutrons and in so doing requires nearly 100 percent pure (or Pu) fuel. Although reactor... 

Rupture disks are often placed below a safety valve to prevent corrosive, tarring or other material from entering the valve nozzle. Only disks which do not disintegrate when they burst (Figures 7-10, 7-11, 7-12, 7-18) can be used below a safety valve, as foreign pieces which enter the valve might render it useless. This is acceptable to certain code applications [1]. These disks are also used to pro dde secondary relief when in parallel tvith safety valves set at lower pressures. They can also be installed on the discharge of a safety valve to prevent loss of hazardous vapors, but caution should be used in anv serious situation. 

In trials with wood since 1910, several researchers did notice pyrolytic heat release, but others found the reaction endothermic. The contradictions can be explained with different sizes of the samples. It is believed that primary pyrolysis volatiles interact in secondary, exothermic reactions catalyzed by the solid residue. Long residence times of the volatiles in the disintegrating material favor secondary reactions, of course. Residence times are indeed long in large and in slowly disintegrating samples, in which the volatiles have a long path to the surface and migrate out slowly. 

Secondary Breakup Disintegration of Fragments/ Droplets into Smaller Ones... 

The following factors must be considered when assessing the stability of the casein micelle The role of Ca++ is very significant in milk. More than 90% of the calcium content of skim milk is associated in some way or another with the casein micelle. The removal of Ca++ leads to reversible dissociation of P-casein without micellular disintegration. The addition of Ca++ leads to aggregation. The same reaction occurs between the individual caseins in the micelle, but not as much because there is no secondary structure in casein proteins. 

Secondary atomization, the breakup of the drops first formed, has been studied by Littaye (11C), who assumes a necessary criterion that the drag forces exceed the inertia forces. Ohnesorge (17C) makes use of the principles of mechanical similarity by introducing dimensionless coefficients to help explain jet breakup. Above certain well defined numbers, the jet completely atomizes at the nozzle. Lower values indicate the formation of a jet which disintegrates, owing to helical vibrations which later change into Rayleigh vibrations. 

A few radioisotopes of biochemical significance are y emitters. Emission of a y ray (a photon of electromagnetic radiation) is often a secondary process occurring after the initial decay by /3 emission. The disintegration of the isotope 131I is an example of this multistep process. 

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