Sizing of grains

By 1803,.the British had adopted an identification system consisting of various colored letters and numbers applied to the ends of powder barrels to designate the type of propellant, the size of grain, special ingredients used in its manufacture, and method of processing. 

Tests conducted at Picatinny Arsenal with these devices showed that fairly consistent results may be obtained for a given explosive if all determinations are made under the same conditions (same rate of heating, size of grains,... 

Single-base propints were subdivided accdg to shape and sizes of grains into Mk 1 (squares of flat strips) Mk2 (squares) Mk3 (strips) ... 

Previously, polycrystalline Mn-Zn ferrite had been prepared by solid state reaction in vacuo or by hot-press methods. Using these methods densification and the size of grains could be controlled, but control of the 5 value was a problem. Tanaka succeeded in preparing high performance Mn-Zn ferrites by controlling Poz-... 

Wheat Starch,—The amylaceous corpuscles of wheat differ somewhat among themselves in appearance and size of grain, but generally they are composed of... 

The influence of the size particles of catalysts on the chemical yields of heterogeneous photocatalytic reactions, has received little attention, however our results suggest that both factors, the size of grains and the concentration of catalyst, must play an important role for light scattering and reflexion pro cesses these factors can influence the quantum yields and consequently the che mical yields of the photogenerated products. 

As there is no info at our disposal on current British BkPdrs, we are using here the description given in Thorpe(Ref 13a,p 584). The powders used in England were classified according to the size of grain. Some of them described below are definitely obsolete... 

US Specification requirements for sizes of grains used in cannon proplnts are briefly discussed under Cannon Propellants, Analytical Procedures... 

Stettbacher(Ref 61) reported that the compn prepn of Swiss NC proplnts were similar to Fr Poudre B. They differed only in form and size of grains. These proplnts were prepd by mixing in a "Knettmachine (kneading machine), and in the presence of eth-alc, 80 Guncotton(13 13,4%N) and 20% Collodion Cotton (11.7-12.2%N) to which was added 1-1.5%... 

DPhA. The gelatinized mass was worked to the desired shape size of grains, and the vol sol evaporated by drying. These proplnts were manufd by "Die Eidgenossische(Staatliche) Pulverfabrik in Wimms(Bern)(See Ref 27)... 

A relative decrease in Tafel slope has been observed with steel subjected to thermal treatments leading to different microstructures [274]. In this case an effect can indeed be expected because of the possible formation of different phases or different proportions (martensite vs ferrite) of phases (Fig. 10). An effect of the size of grains has been observed on the Tafel slope. 

The particle size of grain processed in a hammer mill is affected mainly by the size of the screen used, although the speed of the hammer mill and the flow rate also affect it. 

According to the data available in literature size of grains in technical pure, not annealed aluminum equals d=90 jm. Let us take the cavities in the form of tubes. The length of the tube equals the size of the grains. The transverse dimension of the probes not undergoing loading is y=10% of the length. 

Laboratory Record. The working directions, in the section entitled procedure, are to be kept at hand while carrying out the manipulations. These directions do not need to be copied in the laboratory note book but it is essential, nevertheless, to keep a laboratory record in which are entered all important observations and data, such, for example, as appearance of solutions (color, turbidity) appearance of precipitates or crystals (color, size of grains, crystalline form) results of all weighings or measurements number of recrystallizations results of test for purity of materials and products, etc. 

The influence of temperature on the electrical resistivity can be considered as another criterion for the phase composition of VO2. This dependence is shown in Figure 8. The size in the jump of resistivity of VO199 ceramics in Figure 8 (a) and of VO. 9g ceramics in Figure 8 (b) is about 10 at 66°C and 10 at 64°C, respectively. These are consistent with the transition heats and temperatures of VO2 powders in Table 1. The research of another composition VO2 ceramic is carrying on. The results of XRD show that the size of grain in the ceramics is about 60nm. 

The nickel electrodeposition into pores of mesoporous silicon begins from the metal grain formation randomly all over the surface of the silicon skeleton. The size of grains increases up to 100 nm with the deposition time and further nickel deposition is accompanied by the increase in the number of grains, which finally coalesce to threads. The moment of complete pore filling with nickel is controlled by the surface potential of the sample. 

The surface of microcapsules has a granular structure (Fig. 2b). The average size of grains is 84.0 13.0 nm. Such morphology is probably related to... 

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