Thermochemical and Energy Characteristics of DNTF and DNFF

Bis(4-nitrofurazan-3-yl)furazan (DNTF) and 3,4-bis(4-nitrofurazan-3-yl)furoxan (DNFF) have been studied as potential components of composite solid rocket propellants. Their heats of combustion and enthalpies of formation have been determined experimentally. X-ray diffraction analysis has shown that the DNTF and DNFF crystals are orthogonal with the same space group P2₁2₁2₁. It has been found DNTF and DNFF are ineffective in rocket propellants with a hydrocarbon binder; however, when using DNTF for compositions without aluminum and with an active binder, it is easy to provide a specific impulse of 254.5 s at combustor and nozzle exit pressures of 40 and 1 atm, respectively, and at a density of 1.77 g/cm³, and when using DNFF, a specific impulse of 258 s at a density of 1.79 g/cm³.     

Development of Detonation Flame Sprayed Cu-Base Coatings Containing Large Ceramic Particles

Metal-matrix composites (MMCs) containing large ceramic particles as superabrasives are typically used for grinding stone, minerals, and concrete. Sintering and brazing are the key manufacturing technologies for grinding tool production. However, restricted geometry flexibility and the absence of repair possibilities for damaged tool surfaces, as well as difficulties of controlling material interfaces, are the main weaknesses of these production processes. Thermal spraying offers the possibility to avoid these restrictions. The research for this paper investigated a fabrication method based on the use of detonation flame spraying technology to bond large superabrasive particles (150-600 μm, needed for grinding minerals and stones) in a metallic matrix. Layer morphology and bonding quality are evaluated with respect to superabrasive material, geometry, spraying, and powder-injection parameters. The influence of process temperature and the possibilities of thermal treatment of MMC layers are analyzed. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

Study of Spin-Tunnel Junction Magnetization Using Coherent Rotation of the Free Layer Magnetization Model

Russian Microelectronics - The influence of a magnetic field directed orthogonal to the easy magnetization axis (EMA) of an elliptical spin-tunnel junction based on the...     

The use of evolutionary programming based on training examples for the generation of finite state machines for controlling objects with complex behavior

It is proposed to use evolutionary programming to generate finite state machines (FSMs) for controlling objects with complex behavior. The well-know approach in which the FSM performance is evaluated by simulation, which is typically time consuming, is replaced with comparison of the object’s behavior controlled by the FSM with the behavior of this object controlled by a human. A feature of the proposed approach is that it makes it possible to deal with objects that have not only discrete but also continuous parameters. The use of this approach is illustrated by designing an FSM controlling a model aircraft executing a loop-the-loop maneuver.     

A Helical Magnetic-Cumulation Generator with a Compact Transformer

Experimental data on a helical magnetic-cumulation generator with an output step-up transformer formed by two coaxial solenoids is presented. The inner diameter of the helix is 50 mm. Compared with the transformers described earlier, this transformer has a smaller size. The transformer can feed an energy of 1 kJ into a 100-H high-impedance load.     

Investigations of BOR-60 Structural Materials and Prospects for Further Work

Since its startup in December in 1969, the BOR-60 reactor has been used effectively for irradiation of structural and fuel materials in a wide range of dose–temperature parameters. Analysis of the actual computational-experimental parameters (irradiation temperature, damage rates) shows that the irradiation conditions are highly reproducible and can be maintained accurately.The investigations made it possible to study phenomena which are important for building reactors using domestic structural materials and to choose the optimal composition and heat treatment of the materials.New directions are indicated for scientific-research work, for improving and increasing the service life of VVÉR type reactors, and for developing new-generation structural materials for fusion reactors being designed.