Nanoscale Crystallization in the Amorphous Alloy Fe79P14.2Si4.4Mn2.2V0.2 upon Pulsed Photon Annealing

The effect of pulsed photon annealing with energy densities from 1.4 to 42 J/cm² for various lengths of time on the structure of the amorphous alloy Fe₇₉P_14.2Si_4.4Mn_2.2V_0.2 was studied by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The results demonstrate that short-term irradiation with low energy densities leads to surface relaxation of the amorphous alloy, increases the strength of the surface layer, and reduces the internal-friction peak. Longer term photon annealing leads to crystallization of the alloy throughout the sample thickness.     

Web-based systems design: a study of contemporary practices and an explanatory framework based on “method-in-action”

This paper reports the findings of a detailed study of Web-based systems design (WBSD) practices in Ireland based on data collected over a 3-year period (2002–2005), the objectives of which were to (1) contribute towards a richer understanding of the current “real-world” context of WBSD by characterising the profile of a typical project (team size, timeframe, nature of requirements, etc.) and identifying the key challenges, constraints, and imperatives (i.e. “mediating factors”) faced by Web-based system designers, and (2) understand how those contextual parameters and mediating factors influence the activity of WBSD as regards the selection and enactment of whatever design practices are therefore engaged (i.e. the use of methods, procedures, etc.). Data was gathered through a survey which yielded 165 usable responses, and later through a series of semi-structured qualitative interviews. Using grounded theory, an explanatory conceptual framework is derived, based on an extension of the “method-in-action” model, the application of which to WBSD has not been previously investigated in depth. It is proposed that this framework of WBSD issues is valuable in a number of ways to educators, researchers, practitioners, and method engineers.     

Comparative Assessment of the Effect of Chemical and Radiation Factors on Workers and the General Public Resulting from the Salvaging of Nuclear-Powered Submarines

The results of observations performed over many years are used to make an assessment of the degree to which the concentration of chemical and radioactive substances escaping into the environment during salvaging of nuclear-powered submarines exceeds the admissable norms for workers at the main ship-repair facilities in Russia and for the general public in the surrounding territories. It is shown that the chemical substances are a determining factor in environmental contamination. Their content in the atmosphere and sea water exceeds the admissable norms near sources, on the territory of the enterprises, and (for individual indicators) at populated points. Under these conditions, the concentration of technogenic radionuclides does not exceed the admissable norms and its damaging effect on man is hundreds and thousands of times less than that of chemicals.     

Special Features of Fracture of Steels from Partially-Alloyed Powders

Special features of fracture of structural steels 45N2D2M and 45N4D2M manufactured by pressing with subsequent sintering from partially alloyed iron powders are studied. Impact bending tests of specimens with different levels of retained porosity show two kinds of fracture, i.e., intraparticle cleavage and interparticle dimple fracture. In addition, the surfaces of the “initial” pores come out to the fracture surface. Other conditions being equal, growth in porosity decreases the proportion of the brittle component of fracture and decreases the critical brittle point.     

Gradient interpenetrating polymer networks

The methods of synthesis and properties of gradient interpenetrating polymer networks (IPN) are discussed based on literature and authors' own experimental data. Gradient IPN can be treated as a sequence of an infinite number of layers of IPNs, whose composition and properties vary gradually from the surface to the core of specimens. These are analysed the most important properties of gradient IPNs: temperature transitions, thermodynamic and physico-mechanical characteristics and the main direction of practical application of gradient IPN-based materials.