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A study is performed of the production of the 178m2Hf isomer (T1/2 = 31 years) upon the neutron irradiation of natural hafnium in a water-moderated reactor with a neutron fluence of ~1022 cm−2. It is shown that the 178m2Hf isomer forms mainly in reactions between fast neutrons and isotopes 178Hf or 179Hf. The specific activity of the isomer in irradiated hafnium is around 2 kBq g−1. [ABSTRACT FROM AUTHOR]

New results of measurements of the dependences of the flux of reactor antineutrinos and their spectrum on the distance from the center of the core of the SM-3 reactor (Dimitrovgrad, Russia) in the range from 6 to 12 m are presented. Additional measurements were conducted. The volume of accumulated experimental data was increased nearly by a factor of two. A model-independent analysis was performed on the basis of all data in order to determine the oscillation parameters and . The method of a coherent summation of measurement results makes it possible to demonstrate directly the oscillation effect. We observed the oscillation effect at a level of three standard deviations () in the vicinities of parameters values of eV and . Combining the results of the Neutrino-4 experiment with results for the gallium anomaly and for the reactor anomaly, we obtained the following value: . [ABSTRACT FROM AUTHOR]

The paper considers the results of long-term observations of megacusp (large-scale shoreline cusps) on the coast of the Gulf of Terpenya (Gulf of Patience), Sakhalin Island. The typical spatial step of the rhythmic forms is about 800 m, and the amplitude of shoreline undulations is 40–50 m. Despite significant changes on time scales of seasons, years, and decades, the main morphological features of the megacusps are preserved for more than 60 years. A model is proposed that explains the evolution of rhythmic shoreline patterns by self-organization of the bottom relief under wave impact. Development of megacusps is shown to be related to the generation of nearshore circulation cells; due to flows within the cells, a small initial perturbation to the shoreline contour can increase over time. A positive feedback between the coastal morphology and hydrodynamics arises when a certain relation is established between the length of the perturbation, the width of the surf zone, and the speeds of nearshore currents. It is concluded that the megacusp system in the Gulf of Terpenya is mainly supported by moderate waves with a significant wave height of ~1.6 m. [ABSTRACT FROM AUTHOR]

We report Neutrino-4 experiment results of measurements of reactor antineutrinos flux and spectrum dependence on the distance in range 6–12 m from the center of the reactor core. The fit of experimental dependence with the law 1/L2, where L is the distance from the reactor center, gave satisfactory result with goodness of fit 81%. However, we discovered that the experimental neutrino spectrum is different from the calculated one. Using experimental spectrum, we performed the model independent analysis of restrictions on oscillation parameters Δm142 and sin2 2θ14. The results of this analysis exclude area of reactor and gallium anomaly at CL more than 99.7% (>3σ) for values Δm142 < 3 eV2 and sin2 2θ14 > 0.1. However, we observed an oscillation effect at CL 2.8σ in vicinity of Δm142 Δm142 ≈ 7.3 eV2 and sin2 2θ14 ≈ 0.39. The method of coherent addition of results of measurements, which allows us to directly observe the effect of oscillations, is proposed. The analysis of that effect is presented. In general, it seems that the effect predicted in gallium and reactor experiments is being confirmed but at sufficiently large value of Δm142. Future prospects of the experiment are discussed. [ABSTRACT FROM AUTHOR]

Comparative studies of peculiarities of the formation, thermal stability of the structure, and mechanical properties of heat-resistant alloys based on iron and nickel and fabricated using additive technologies (ATs) by laser metal deposition and selective laser melting are performed. It is established that a cellular structure is formed in alloys fabricated by the laser metal deposition and small pores up to 200 nm in size are present. The structure of alloys fabricated by selective laser melting contains elements with a globular and lamellar morphology and incompletely melted regions, as well as large pores on the order of 5 μm in size. The possibility of manifestation of the nanophase hardening effect due to the presence of nanodimensional particles of chromium silicides is shown. A comparative analysis of mechanical properties of materials under study is performed. It is shown that iron-based alloys possess higher strength and lower ductility when compared with nickel alloys. All studied samples fabricated by selective laser melting have higher strength characteristics when compared with alloys fabricated by laser metal deposition. Short-term annealing at 900-1000°C for 1 h noticeably decreases both strength and plasticity in tensile and compression tests at room and elevated temperatures. Alloys based on iron and nickel fabricated by laser metal deposition and subjected to compression tests at t = 900°C have similar strength characteristics. In contrast with iron-based alloys, additional annealing of the nickel-based AT alloy almost does not decrease its strength characteristics. [ABSTRACT FROM AUTHOR]

Parameters of a noisy Lorenz system were reconstructed from its time series using the method of proper coordinates. The effects of low- and high-frequency additive and multiplicative noise on the relative error of reconstruction of the system parameters have been studied. It is demonstrated that the method of proper coordinates provides for increased accuracy of reconstruction of the Lorenz system parameters in the presence of additive noise. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]