Драйверы и тормозы развития ядерной энергетики

Many countries, for one reason or another, suffer from a shortage of fossil fuels, which have been the main source of primary energy in the world for more than 200 years. As early as the 1960s, nuclear power plants with lower production costs than fossil fuel condensing power plants began to be built. This created a widespread demand for nuclear power plants in many not only developed but also developing countries. However, the spread of nuclear power as a primary energy source has been very uneven. Periods of accelerated growth of nuclear power alternate with periods of deceleration and even stagnation. A wide palette of factors influencing both the growth of nuclear power (energy balance deficit, countries' desire for energy independence and reduction of energy supply costs, threat of global warming on Earth, depletion of fossil fuel resources, use of economies of scale, etc.) and its inhibition (assessment of the acceptability of nuclear energy as a primary energy source, lack of knowledge about the development of nuclear reactions in nuclear reactors, complexity of human and technical systems, serious a It is shown that a realistic, objective and comprehensive assessment of the whole palette of drivers and limiting factors of nuclear power growth requires an interdisciplinary approach and contributes to improving the quality of forecasting the development of nuclear power and society as a whole

Formation Features of Hybrid Magnetic Materials Based on Polyphenoxazine and Magnetite Nanoparticles

Hybrid metal-polymer nanocomposite materials based on polyphenoxazine (PPhOA) and Fe3O4 nanoparticles were obtained for the first time via two methods: in situ oxidative polymerization of phenoxazine (PhOA) in an aqueous solution of isopropyl alcohol with nanoparticles of Fe3O4 being present; chemical transformations of PPhOA subjected to IR heating at 400–450 °C in the presence of FeCl3·6H2O in an inert atmosphere. Obtained hybrid Fe3O4/PPhOA nanomaterials were characterized by means of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic absorption spectrometry (AAS), elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), as well as by vibrating sample magnetometry. The chemical structure, phase composition, magnetic and thermal properties of obtained nanocomposites were investigated in relation to the synthesis conditions

Magnetic Characterization of Fischer-Tropsch Catalysts

INGENIERIE+JDAInternational audienceThis paper reviews recent developments in the application of magnetic methods for investigation of Fischer-Tropsch catalysts involving cobalt, iron and nickel. Magnetic characterization provides valuable information about catalyst reduction, sizes of ferromagnetic nanoparticles, chemisorption on ferromagnetics and topochemical reactions which occur with the catalysts during the genesis of the active phase and in the conditions of Fischer-Tropsch synthesis. The capabilities and challenges of the magnetic methods are discussed.Cet article passe en revue les développements récents dans le domaine de la caractérisation des catalyseurs Fischer-Tropsch à base de cobalt, de fer et de nickel par la méthode magnétique. La caractérisation magnétique fournit des informations précieuses sur la réduction du catalyseur, la taille des nanoparticules ferromagnétiques, la chimisorption, ainsi que sur les réactions topo chimiques qui se produisent avec les catalyseurs au cours de la genèse de la phase active et dans des conditions réactionnelles. Les possibilités et les limites de la méthode magnétique sont examinée

Stochastic Dynamics of Magnetosomes in Cytoskeleton

Rotations of microscopic magnetic particles, magnetosomes, embedded into the cytoskeleton and subjected to the influence of an ac magnetic field and thermal noise are considered. Magnetosome dynamics is shown to comply with the conditions of the stochastic resonance under not-too-tight constraints on the character of the particle's fastening. The excursion of regular rotations attains the value of order of radian that facilitates explaining the biological effects of low-frequency weak magnetic fields and geomagnetic fluctuations. Such 1-rad rotations are effectively controlled by slow magnetic field variations of the order of 200 nT.Comment: LaTeX2e, 7 pages with 3 figure

Classical glueballs in non-Abelian Born-Infeld theory

It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action suggested by the superstring theory gives rise to classical particle-like solutions prohibited in the standard Yang-Mills theory. This becomes possible due to the scale invariance breaking by the Born-Infeld non-linearity. New classical glueballs are sphaleronic in nature and exhibit a striking similarity with the Bartnik-McKinnon solutions of the Yang-Mills theory coupled to gravity.Comment: Revtex, 4 pages, 2 eps figure

Galactic Gradients, Postbiological Evolution and the Apparent Failure of SETI

Motivated by recent developments impacting our view of Fermi's paradox (absence of extraterrestrials and their manifestations from our past light cone), we suggest a reassessment of the problem itself, as well as of strategies employed by SETI projects so far. The need for such reevaluation is fueled not only by the failure of searches thus far, but also by great advances recently made in astrophysics, astrobiology, computer science and future studies, which have remained largely ignored in SETI practice. As an example of the new approach, we consider the effects of the observed metallicity and temperature gradients in the Milky Way on the spatial distribution of hypothetical advanced extraterrestrial intelligent communities. While, obviously, properties of such communities and their sociological and technological preferences are entirely unknown, we assume that (1) they operate in agreement with the known laws of physics, and (2) that at some point they typically become motivated by a meta-principle embodying the central role of information-processing; a prototype of the latter is the recently suggested Intelligence Principle of Steven J. Dick. There are specific conclusions of practical interest to be drawn from coupling of these reasonable assumptions with the astrophysical and astrochemical structure of the Galaxy. In particular, we suggest that the outer regions of the Galactic disk are most likely locations for advanced SETI targets, and that intelligent communities will tend to migrate outward through the Galaxy as their capacities of information-processing increase, for both thermodynamical and astrochemical reasons. This can also be regarded as a possible generalization of the Galactic Habitable Zone, concept currently much investigated in astrobiology.Comment: 30 pages, 2 figure

Researches of two and three-output structures with effect of resonant tunneling

The present paper is devoted to the development of production process of transistor structures with effect of resonant tunneling (RTT), researching static and dynamic characteristics and working frequency band of the samples and definition of possible areas of their application