Priming Action

It can be poured while molten(mp 94°) directly into detonator caps it does not form compds with metals used for casings and its priming action is higher than that of MF or LA but its action is less brisantl 62)W.C.Cope,USP 1399104(1922) ... 

The position of the converter domain depends on whether the relay helix has a kink near its middle point. The kink in the relay helix occurs in the pre-powerstroke state. The kink leads to a rotation of the converter domain through 60°. Removing the kink causes the lever arm to rotate back by 60°, which is the elementary structural event in the powerstroke. Conversely, creating the kink is the priming action necessary to reach the start of the powerstroke. 

AA is known to Inactivate viruses (Murata and Uike, 1976) and antltumorlc reductones like AA depolymerIzed nucleic acids and alter the priming action of DNA for DNA—polymerase (Omura et al., 1975 1978). 

Sauerbeck has reported both positive and negative priming actions in... 

JENKINSON D.S. 1966. The priming action. In The use of isotopes in soil organic matter studies. Report of the FAO/IAEA meeting, Vienna. Pergamon Press, Oxford. 

Entrainment occurs when spray or froth formed on one tray enters the gas passages in the tray above. In moderate amounts, entrainment will impair the countercurrent action and hence drastically decrease the efficiency. If it happens in excessive amounts, the condition is called priming and will eventually flood the downcomers. 

The mode of action has not yet been elucidated but the manufacturer states that it probably behaves like the herbicide triflurolin and its congeners. These materials inhibit cell division by binding to tubuHn thereby internipting micro-tubule development. This, in turn, stops spindle fiber formation essential to mitosis and cell division. Experiments with C-labeled Prime+ show that it is acutely toxic to fish with estimated LC q (96 h) of less than 100 ppb for rainbow trout and bluegiU. sunfish. However, channel catfish did not exhibit any toxic response at the maximum attainable water concentration (10). 

The detection of spectral sensitizing action often depends on amplification methods such as photographic or electrophotographic development or, alternatively, on chemical or biochemical detection of reaction products. Separation of the photosensitization reaction from the detection step or the chemical reaction allows selection of the most effective spectral sensitizers. Prime considerations for spectral sensitizing dyes include the range of wavelengths needed for sensitization and the absolute efficiency of the spectrally sensitized process. Because both sensitization wavelength and efficiency are important, optimum sensitizers vary considerably in their stmctures and properties. 

These two types of flooding are usuaUy considered separately when a plate column is being rated for capacity. For identification purposes they are caUed entrainment flooding (or priming ) and downflow flooding. When counterflow action is destroyed by either type, transfer efficiency is lost and reasonable design hmits have been exceeded. 

Soft slarlers, star-delta, wound motor and A/T starters, or when the prime mover is fitted with centrifugal dutches or delayed-action fluid couplings... 

To these may be added Blicke and Kaplan s conclusion, that the nature of the basic nucleus and the relative positions of the phenyl and hydroxyl groups in the esterifying acid are of prime importance. These conclusions do not provide a full explanation of the results of these investigations. It seems clear that chemical structure alone provides an insufficient basis and that molecular size and shape and other physical properties of the substance play a considerable part in determining the pharmacological action. 

Hydrogen sulfide is the only thermodynamically stable sulfane it occurs widely in nature as a result of volcanic or bacterial action and is, indeed, a prime source of elemental 8 (p. 647). It has been known since earliest times and its classical chemistry has been extensively studied since the seventeenth century.H28 is a foul smelling, very poisonous gas familiar to all students of chemistry. Its smell is noticeable at 0.02 ppm but the gas tends to anaesthetize the olefactory senses and the intensity of the smell is therefore a dangerously unreliable guide to its concentration. H28 causes irritation at 5 ppm, headaches and nausea at 10 ppm and immediate paralysis and death at 100 ppm it is therefore as toxic and as dangerous as HCN. 

Positive displacement pumps are self-priming by their normal operating action and are designed to cope with mnning dry. Centrifugal pumps are not inherently selfpriming, and need to be provided with assistance in the form of ejectors, as in Figure 32.56 or dry vacuum pump systems. In these systems, a dry vacuum pump allows air to be drawn out and where an automatic valve prevents... 

Noise from a compressor plant arises at different sources, and each source has its own pattern of sound pressure levels. Noise levels can be divided into two groups, the low-frequency pulsating air intake sound and the higher-frequency machine noise from compressor, prime mover and fans. Local statutory regulations on noise levels should be determined, and action taken by the supplier to ensure that the noise levels do not exceed those stipulated. 

The hardness of an enamel surface is an important property for such items as enamelled sink units, domestic appliances, washing machine tubs which have to withstand the abrasive action of buttons, etc. On Moh s scale most enamels have a hardness of up to 6 (orthoclase). There are two types of hardness of importance to users of enamel, viz. surface and subsurface. The former is more important for domestic uses when one considers the scratching action of cutlery, pans, etc. whereas subsurface hardness is the prime factor in prolonging the life of enamelled scoops, buckets, etc. in such applications as elevators or conveyors of coal and other minerals. 

Percussion. The act of striking one body against another with a sharp blow. As some expls, such as MF or LSt are very sensitive to such a blow (shock or impact), they may be expld (or ignited) by such action. In this case, the term percussion can be applied to initiation or priming by such action, as weil as to the expln (or deflagration or ignition) caused by percussion... 

Pb Azide (LA), which is the most important expl used in detonators (Ref 11), although extremely sensitive to shock, heat, and friction, is not sufficiently sensitive to stab action to insure 100% reliability in firing from the stab action. Consequently, the priming mixt is used as a first-fire layer in these units. RDX (cyclotri-methylenetrinitramine), also known as Cyclo-nite, is contained as the output charge of the typical stab detonator. Its output results in a detonation of other expls (Ref 11)... 

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