Dynamics Modelling of Hexaslides using the Decoupled Natural Orthogonal Complement Matrices

In this paper, dynamic model of a class of parallel systems, namely, the hexaslides, is proposed. The model developed is based on the concept the decoupled natural orthogonal complement (DeNOC) matrices, introduced elsewhere. The dynamic model of hexslides, though complex due to the existence of multi-loop kinematic chains, is required for actuator power estimation, computed-torque control, optimum tool trajectory generation, etc. The use of DeNOC offers many physical interpretations, recursive algorithms, and parallel computations. Using the proposed dynamic model, a parallel inverse dynamics algorithm has been presented to compute the actuator forces. This is useful to choose suitable motors for an application. An illustration is provided using an existing machine tool based on hexaslides, namely, the HexaM, while it is carrying out a circular contouring. Secondly, the effect of leg and slider inertias is also studied, which clearly suggests that neither of these can be neglected while finding the actuator forces.     

Dual-purpose technologies in view of diversification of the military-industrial complex of Russia

Current problems in scientific-information support of the process of diversification of the military-industrial complex (or defense-industrial complex, DIC) of Russia are considered, which can facilitate the effective usage of dual-purpose technologies in various civilian fields of the national economy. In this context, the program of the 7th Specialized Exhibition “Dual-Purpose Products and Technologies: DIC Diversification,” which was held in Moscow in October 2006, is analyzed.     

Aggregation stability of mixtures of vacuum distillate and mazut

Chemistry and Technology of Fuels and Oils -     

NITRITE REDUCTASE IN SALMONELLA TYPHIMURIUM

A nitrite reductase was identified and purified 11 -fold from the cytoplasmic fraction of Salmonella typhimurium grown anaerobically with nitrite as the sole nitrogen source. The enzyme required NADH as a cofactor and showed maximum in vitro reductase activity at pH 8.0.
S. typhimurium, grown anaerobically in glucose-limited minimal medium containing peptone and nitrite, showed shorter generation times and increased cell yields in comparison to nitrite-free cultures. The presence of nitrite had no effect on aerobic cultures. The nitrite reductase functions in a dissimilatory manner and appears to be primarily involved in physiological energy generation during anaerobic growth. The nitrite reductase may function to remove excess reducing power in the form of NADH from the cell thus increasing ATP production during the anaerobic fermentation of glucose. The formation and subsequent assimilation of ammonia from nitrite is of secondary importance to the organism.