Interchange Configuration

Wiebelt J.A., Ruo S.Y. (1963) Radiant-interchange configuration factors for finite right circular cylinder to rectangular plane. International Journal of Heat Mass Transfer 6, 143-146. 

Hamilton, D. C., and W. R. Morgan Radiant Interchange Configuration Factors, NACA Tech. Note 2836, 1952. 

Fig. 53. Hard sphere model of three interchangeable configurations for the atom pairs of Mo on the W 21l plane. Small open circles on each surface channel indicate the adsorption sites for adatoms, separated, respectively, by 2.7 A. (From ref. 414.)...

For liquids, the last term in Eq. VIl-5 is zero, so that r = G or t = 7, since we will use G and 7 interchangeably) the same would be true of a solid if the change in area dA were to occur in such a way that an equilibrium surface configuration was always maintained. Thus the stretching of a wire under reversible... 

The seal unit located at each end of the multistage compressor rotor is installed as a cartridge. The cartridge has positive locating features to permit proper placement on installation. It normally includes a provision to ensure that cartridges are not interchanged from the intended end. This is to prevent reverse rotation on the unidirectional configurations. 

Many workers have employed pre-cracked specimens in a number of configurations that permit interchangeable data to be obtained from an analysis derived with fracture mechanics. The pre-crack provides an ideal crevice for... 

Each element of K effects an interchange of the s points and thus a permutation of the configurations (0j,. .., 0 ) of content These permutations form a representation of the group... 

This interchangeability of components gives rise to very many RO configuration permutations and provides for a wide flexibility in system design, but may make the direct comparison of competing RO plants difficult at times. 

In the previous chapters, we discussed electron distrihution in organic molecules. In this chapter, we discuss the three-dimensional stracture of organic compounds. The structure may be such that stereoisomerism is possible. Stereoisomers are compounds made up of the same atoms bonded by the same sequence of bonds but having different three-dimensional stracmres which are not interchangeable. These three-dimensional structures are called configurations. 

When the system is made up of identical particles (e.g. electrons in a molecule) the Hamiltonian must be symmetrical with respect to any interchange of the space and spin coordinates of the particles. Thus an interchange operator P that permutes the variables qi and (denoting space and spin coordinates) of particles i and j commutes with the Hamiltonian, [.Pij, H] = 0. Since two successive interchanges of and qj return the particles to the initial configuration, it follows that P = /, and the eigenvalues of are e = 1. The wave functions corresponding to e = 1 are such that... 

A further finding concerns the stereochemistry of HD and its derivation from PA. Both HD and the primary PAs (monocrotaline, usaramine) that we know to be available to Utetheisa in the field are of the same (7R) stereochemical configuration. It was therefore not surprising to find that Utetheisa is unable to convert a PA of opposite (7S) stereochemistry (heliotrine) into HD. However, we found another arctiid moth, the Asian species Creatonotus transiens, which also produces HD in its coremata, to be able to use 7R and 7S PAs interchangeably for HD production (31). We are tempted to conclude that Creatonotus, unlike Utetheisa, has dietary access to PAs of both stereochemical configurations in its environment. 

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