Sandwich propellants

Hightower and Price (H8) have conducted studies on burned and quenched ammonium perchlorate single crystals and two-dimensional propellant sandwiches prepared by laminating a thin binder layer between two ammonium... 

W. Nachbar, A Theoretical Study of the Burning of a solid Propellant Sandwich, in Solid Propellant Rocket Research, vol. 1 of Progress in Astronautics and Rocketry, M. Summerfield, ed.. New York Academic Press, 1960. 207-226. 

Fig. 17. Sandwich model for combustion zone of composite propellants (Nl).

Complexes of mono-valence cations (Na+, K+) sandwiched between two T tetrads (also U tetrads) have been found to adopt an Ss-symmetry [31]. It is interesting to note that intercalating a cation between two T tetrads does not alter the propeller-like structure of T tetrad. Similarly, U tetrads in the cation sandwiched U tetrads complex adopt the bowl-like structure. 

Diffusion Cells. The two chamber diffusion cells (9) were assembled by a No. 18 spring clamp with the hairless mouse3skin sandwiched in between. The volume of each half cell was 2.0 cm. An 8 mm stirrer made of stainless steel and equipped with a small teflon propeller was driven by a 150 rpm constant speed motor (Hurst, Princeton, IN) was utilized for stirring. The assembled cell was then immersed in a 37°C heated water bath (Haake, Karlsruhe, W. Germany), so that the stirring and sampling ports were the only components above the water surface. The diffusion cell was kept for 10 minutes in the water bath to allow temperature equilibrium prior to any experiment. Then ethanol/saline mixtures preheated to 37°C were pipetted into the cell to start an experiment. 

For heterogeneous propellants, the current situation is much less satisfactory. The complexity of the combustion process was discussed in Section 7.7. To employ a result like equation (66) directly is questionable, although attempts have been made to evaluate parameters like A and B of equations (67) and (68) from complicated combustion models for use in response-function calculations [81], [82]. Relatively few theories have been addressed specifically to the acoustic response of heterogeneous propellants [82]. Applications of time-lag concepts to account for various aspects of heterogeneity have been made [60], [83], a simplified model—including transient variations in stoichiometry—has been developed [84], and the sideways sandwich model, described in Section 7,7, has been explored for calculating the acoustic response [85], There are reviews of the early studies [7] and of more recent work [82],... 

The crystal structure of galactose oxidase from the fungus Dactylium dendroides has been determined. Accordingly, galactose oxidase (639 amino acid residues) consists of three domains predominantly formed from /3-structures (Figure 14). The first domain (residues 1-155) has a /3-sandwich structure. The catalytic domain (residues 156-532) comprises a seven-fold /3-propeller based on the kelch structural motif The copper lies on the solvent-accessible surface of this domain close to the pseudo seven-fold axis. The third domain (residues 533-639) is comprised of seven /3-strands. The copper site on the second domain lies in a region extremely rich... 

Figure 4.26. Flow system and setup for simultaneous multicomponent gradient scanning by flame photometric FI A embodying standard addition. The sample (5) is initially aspirated into loop L, which upon turning of the valve (V) is propelled forward by pump P through the FI A system and toward the detector (F), the sample being sandwiched between the inert carrier solution (water) and an infinitely long zone of standard carrier solution (SC) F, flame nebulizer-burner T, timer A/, scanning monochromator O, storage oscilloscope and R, X-Y recorder.

For the half-sandwich Ru complexes shown in Schemes 17-19 we succeeded for the first time in isolating compounds which only differ in the propeller sense of the triphenylphosphine ligand [27]. 

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