Synthesis of an active vibrational-protection system

The synthesis of active vibrational-protection systems is considered for the example of a spring in longitudinal-transverse flexure whose static force-displacement characteristic corresponds approximately to a cubic parabola. The operational characteristics and parameters of a pneumatic damper introduced in a vibrational-protection system are determined.     

System for the creation of complex impact loads

Existing systems for the creation of impact loads are modified by adding vibrations in tests of electronic equipment, without changing the basic operating conditions.     

Rail strengthening in prolonged operation

In rail operation (with traffic corresponding to passed tonnage of gross loads of 500 and 1000 million t), the surface layer of the steel is significantly strengthened. Electron-microscope data permit quantitative analysis of the contribution of different mechanisms to rail strengthening in prolonged operation, at different distances from the contact surface. The strengthening is multifactorial: it involves substructural strengthening associated with nanofragment formation; dispersional strengthening by carbide particles; the formation of atmospheres at dislocations; and polar stress due to interphase and intraphase boundaries. The significant increase in the surface strength of rail steel after prolonged operation (passed tonnage of gross loads of 1000 million t) is due to the presence of long-range internal stress fields and to the fragmentation of material with the formation of nanostructure.     

Oxidation of magnetite

The oxidation of large octahedral single crystals of magnetite extracted from chlorite shale at Shabrovsk talc mine (Middle Urals) is experimentally studied. Differential heating curves show that the processes occurring in the oxidative roasting of magnetite (Fe₃O₄) are highly reproducible. The mechanism of martensite oxidation is considered, as well as the temperature ranges corresponding to exothermal and endothermal reactions. The thermal effect of martensite oxidation is determined from that of a standard (CaCO₃) and the areas under the differential heating curves on the corresponding thermograms. Those areas are proportional to the thermal effect. The results obtained are of considerable interest: knowing the temperature range of martensite oxidation, the heat sources in the various technological zones of the conveyer roasting machines may be taken into account in establishing the roasting conditions, thereby optimizing the thermal conditions and reducing the fuel consumption.     

Solid-Fuel Combustion in the Sintering of Siderite Ore

Two technologies are considered for the preparation of solid fuel used in sintering: crushing with portions of roasted siderite ore whose strength is less than that of the fuel; or crushing of the fuel alone and subsequent mixing with the ore portions. On the basis of derivatographic data, kinetic equations are written for the high-temperature combustion of coke fines in a fuel–ore mixture obtained by the two methods. The most flammable fuel fraction in sintering is established. The results indicate that crushing of the fuel mixed with weaker additives is more effective in terms of decreasing the content of fines in the fuel and hence intensifying the combustion of large pieces.     

Assessment of human physchophysiological states based on methods for heart rate variability analysis

We investigate certain parameters that characterize heart rate variability, as well as combinations of these parameters in terms of assessing their information value for regulating the current psychophysiological state of an operator during a mental stress test. An algorithm has been developed and optimized for dynamic assessment of an operator??s psychological stress level and the stability of his psychophysiological state.     

An ISM,DEI, and ANP based approach for product family development

Product customization has been used for many years, and with this concept, product families can be designed that are better matched to the needs of customers through the use of market segmentation and modular architecture. This study is composed of two phases: the first phase establishes the modular architecture, and taking a bicycle as the case study, applies the Interpretive Structural Model (ISM) to modularize and cluster parts, and then models the connecting relations between the parts numerically using a Disassembly Effort Index (DEI). The second step involves the development of a product family using cluster analysis to divide the experimental samples and the employment of an Analytic Network Process (ANP) to obtain the optimal weight performance of the modules after establishing the market segmentation model. Results of the case study establish four product families and address construction performance of both the common and independent modules between the product families.