Small Potential Energy Release

The time required for internal energy redistribution in a given molecule may depend upon the measurement criteria, the method of activation, the coupling between the internal coordinates, and the level of activation. 

C4He complex. However, recently showed that an excellent 

Marcus has given a generalized prescription for translational energy 

Worry and Marcus have used the tight transition state model to calculate the translational distribution for F + (CH3)2C=CH2 CH3 + CH3CF=CH2. The tight transition state model was in closer accord with observation than the phase space model. Further discussion of these statistical theories is outside the scope of this review. However, we do urge some caution in using statistically based equations without proper investigation into the nature of the assumptions that were used to obtain the final equations. 

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If the iron and stony-iron meteorites came from fully differentiated asteroids, how did these asteroids heat to the point of partial melting and how did the metal segregate from the silicates Unlike large planets, where potential energy release triggers core formation, small asteroids require an additional heat source. The heat source(s) for asteroidal melting produced a wide range of products, from unmetamorphosed chondrites to fully molten asteroids, as well as partially melted asteroids. Samples from these latter asteroids provide us with a rare opportunity to observe core formation—frozen in place. 

The problem of explosion of a vapor cloud is not only that it is potentially very destructive but also that it may occur some distance from the point of vapor release and may thus threaten a considerable area. If the explosion occurs in an unconfined vapor cloud, the energy in the blast wave is generally only a small fraction of the energy theoretically available from the combustion of all the material that constitutes the cloud. The ratio of the actual energy released to that theoretically available from the heat of combustion is referred to as the explosion efficiency. Explosion efficiencies are typically in the range of 1 to 10 percent. A value of 3 percent is often assumed. 

Considerable interest in the subject of C-H bond activation at transition-metal centers has developed in the past several years (2), stimulated by the observation that even saturated hydrocarbons can react with little or no activation energy under appropriate conditions. Interestingly, gas phase studies of the reactions of saturated hydrocarbons at transition-metal centers were reported as early as 1973 (3). More recently, ion cyclotron resonance and ion beam experiments have provided many examples of the activation of both C-H and C-C bonds of alkanes by transition-metal ions in the gas phase (4). These gas phase studies have provided a plethora of highly speculative reaction mechanisms. Conventional mechanistic probes, such as isotopic labeling, have served mainly to indicate the complexity of "simple" processes such as the dehydrogenation of alkanes (5). More sophisticated techniques, such as multiphoton infrared laser activation (6) and the determination of kinetic energy release distributions (7), have revealed important features of the potential energy surfaces associated with the reactions of small molecules at transition metal centers. 

Impurities, such as grit, shreds of cotton, even in small quantities, sensitize an expl to frictional impact. That is why utmost cleanliness must be exercised in the preparation of expls. There are differences in the sensitivity of azides to mechanical and thermal influences. They have been correlated with the structure of the outer electronic orbits, the electrochemical potential, the ionization energy and the arrangement of atoms within the crystal. Functions of the polarizability of the cation are the plastic deformability of the crystals, and their surface properties. The nature of cation in an azide, such as Pb(Nj)2, has little effect on the energy released by the decomposition, which is vested in the N ion. The high heat of formation of the N2 molecule accounts... 

Finally, it is now clear that electron transfer between metal centres occurs readily when there are small differences in redox potential. Reactions which are considerably exothermic may be slower than expected due to difficulty in dissipating the energy released.1409,1421... 

Self-winding watch Small size, renewable power Movement releases potential energy from internal spring Same... 

A small amount of activation energy a is needed to get the ball out of the hollow. Once out, though, it rolls downhill releasing potential energy e ... 

The useful thing about this merry-go-round as far as the cell is concerned is that it provides that critical feature of all desirable energy-releasing systems - a way for the acetic acid molecule to be carefully picked to pieces so as to release its potential energy in small steps. The cycld, as we shall find, is of great importance not only as the final stage of glucose oxidation, but in the metabolism of many other substances as well. We shall later see how, in the breakdown of both fatty and amino acids, products are formed which can enter the cycle at one of several points, to be whirled round the merry-go-round and thus oxidized. 

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