Tail recursion transformation in functional dataflow parallel programs

The peculiarities of transforming functional dataflow parallel programs into programs with finite resources are analysed. It is considered how these transformations are affected by the usage of asynchronous lists, the return of delayed lists and the variation of the data arrival pace relative to the time of its processing. These transformations allow us to generate multiple programs with static parallelism based on one and the same functional dataflow parallel program.     

Modification of the Surface of Magnetic Iron Oxides with Phosphonic Complexones

Protection of Metals and Physical Chemistry of Surfaces - The conditions of chemical modification of the surface of synthetic magnetic iron oxides (magnetite Fe3O4, maghemite γ-Fe2O3) by...     

Deposition and Properties of Phosphate Coatings on Galvanized Steel

It is shown that protective films on galvanized steel can be obtained from alkaline phosphate solutions in the presence of phosphorus-containing ligands. The samples are suggested to be treated in these solutions prior to application of crystalline phosphate coatings. The films obtained are compared with crystalline phosphate coatings by using scanning electron microscopy (SEM) and x-ray diffraction (XRD) methods.     

Study of the process of dissociation of lithium carbonate in the presence of aluminum powder

The results of a study of the dissociation process of lithium carbonate in vacuum in the presence of aluminum powder are presented. It is revealed that at a process temperature of 700°C, the degree of dissociation achieves ∼60% and the thermal decomposition of lithium carbonate retards. It follows from the phase diagram of the Li₂CO₃-Li₂O system that an increase in the temperature leads to the appearance of a liquid phase. On the basis of the experimental data with the use of the half-division method, a maximum rate of heating from 700 to 740°C of 0.33 ± 0.02°C/min is determined at which there is no formation of the low-melting eutectic between the carbonate and lithium oxide. The partial micromelting does not affect the mechanical properties of the briquette. The selected temperature mode provides the uniform thermal decomposition of lithium carbonate over the whole mass of the briquette, which minimizes the possibility of contacts between the carbonate and lithium oxide. Under these conditions, the time of the total degree of dissociation is 2 h. A decrease in the heating rate leads to an increase in the duration of the dissociation process, while its increase leads to the partial melting of the briquette. Aluminum plays the role of an inert additive accelerating the dissociation process at the stage of dissociation.     

Time-pulse measurement of the inductance of iron-free coils

Conclusion The measuring accuracy and time required for the measurement of iron-free induction coils by the time-pulse method are almost entirely determined by the compensating method employed to allow for the error introduced by the active impedance of the coil under test. The method of compensation based on connecting a discretely variable resistance in series with the inductance not only enables the resistance r of the coil to be determined but also gives a more accurate measurement of the inductance. However, in this case the rapidity of action suffers, since the rate of changing the resistance Ry is limited by transient processes in the RL circuit. Compensation methods based on a change in the supply voltage E₀ of the R₀ circuit give greater rapidity. The time required to measure the inductance increases negligibly on using these methods, since noncontact switches may be used to vary the voltage E₀. The greatest rapidity of action is achieved by using the voltage in the test coil itself as the corrective agent, since in this case the rather slow-acting circuits for determining the r/R₀ ratio are unnecessary. However, with this method of compensation the accuracy of the measurements is some four times worse than in the case of a linear variation of the additional voltage.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 55–58, December, 1969.     

Formal verification of programs in the functional data-flow parallel language

The article is devoted to the methods of proving parallel programs correctness, that are based on the axiomatic approach. Formal system for functional data-flow parallel programming language Pifagor is described. On the basis of this system programs correctness could be proved.