[en] Fluidization is investigated as an energy efficient method of removing fines in a machine in which comminution and material transport are integrated features of the design. Two different conditions are explored. In the first, small mono-disperse particles are steadily fluidized within a randomly arranged fixed bed of bigger particles. The results show that the fluidization conditions can be predicted by means of an extension of the general correlations proposed by Richardson and Zaki, and intended for fluidization of mono-disperse particles in confined beds. In the second, a uniformly mixed binary bed of glass spheres is impulsively fluidized. The transient bed behavior is found to be more complex than what can be projected from the present understanding of the steady state. The initial upward motion of the packed bed forms an upward moving void which is essential for segregation to occur. These experimental findings can be directly used to integrate an efficient separation process into new crushing machines. Information on the optimization of the machine working conditions can be extracted from the obtained results

[en] Scaling property of the fragment multiplicity distributions is studied in the framework of two-dimensional bond/site percolation models. It is shown that experimental α-particle multiplicity distributions can be described only in bond percolation model, and at critical value of percolation parameter the normalized moments of all fragment multiplicity distribution decrease with increasing mass number of fragmenting nuclei. Predictions for the forthcoming experimental Au fragmentation into α-fragments are made. 30 refs.; 5 figs. (author)

[en] To a certain extent, concrete removal using water jets can be described as a comminution process. The analysis of crushed particle samples allows an estimation of process efficiency. The calculated maximum value is 7 per cent. At low pressures, the tendency shows a good agreement with values from calculations based on stress-strain behaviour. (orig.)

[en] The intermittence signal on the size frequency of fragments found in various fragmenting systems is reconsidered. We believe that this signal, extracted from a factorial moment analysis, was incorrectly interpreted as a genuine intermittency. Indeed, the analysis in factorial moments made at fixed multiplicity, as it should be, reveals a total absence of proper intermittency in the size distribution. Moreover, in percolation theory this intermittency signal, which has often been claimed in the literature to signal a phase transition, vanishes when the size of the system tends to infinity. Our conclusion is that the signal found in earlier works and interpreted as an intermittency behaviour results from both the power law of the mean size fragment distribution and from the finite width of the multiplicity distribution. We conjecture that any partition of integers exhibiting these two features will provide a similar signal. ((orig.))

[en] It is shown that the effect of a neutron excess of the fragment and target nucleus on the probability of fragmentation is not limited to the effect on the separation energies of the fragments. An additional factor is found which determines the role of the neutron excesses of the fragment and target nucleus

[en] A global view on the properties of fission channels is presented. Surprisingly, the positions of the two asymmetric fission channels are found to be constant in atomic number over the whole range of systems investigated. (author)

[en] It is proved that the fission matrix element can be written like a Sommerfeld-Watson relation. This leads to a dispersion relation for the fission process in which the substraction term is uniquely determined. (author)

[en] (OAK) B202 Technological Feasibility and Performance Characteristics of Fission Fragment Magnetic Collimator Reactors

[en] Mathematical analogues accounting the installation discreteness and finiteness of nuclear registration region (by the path length) correspond to statistical distributions and functional dependences obtained in course of experiments at relativistic nuclei sectioned Cherenkov detector. A criterion for the truth of nuclei fragment identification is presented

No abstract available