Hysteresis and avalanches in the T=0 random-field Ising model with 2-spin-flip dynamics

We study the non-equilibrium behavior of the three-dimensional Gaussian random-field Ising model at T=0 in the presence of a uniform external field using a 2-spin-flip dynamics. The deterministic, history-dependent evolution of the system is compared with the one obtained with the standard 1-spin-flip dynamics used in previous studies of the model. The change in the dynamics yields a significant suppression of coercivity, but the distribution of avalanches (in number and size) stays remarkably similar, except for the largest ones that are responsible for the jump in the saturation magnetization curve at low disorder in the thermodynamic limit. By performing a finite-size scaling study, we find strong evidence that the change in the dynamics does not modify the universality class of the disorder-induced phase transition.Comment: 9 pages, 10 figure

Explosive Ising

We study a two-dimensional kinetic Ising model with Swendsen-Wang dynamics, replacing the usual percolation on top of Ising clusters by explosive percolation. The model exhibits a reversible first-order phase transition with hysteresis. Surprisingly, at the transition flanks the global bond density seems to be equal to the percolation thresholds.Comment: 7 pages, 5 figure

Effective Action Method for Computing Next to Leading Corrections of O(N)O(N) Models

We compute the corrections of next to leading order in the ${1 \over N}$ expansion to the effective potential of a system described by a Ginzburg-Landau model with $N$ components and quartic interaction, in the case of spontaneous symmetry breaking. The method we apply allows to generalize in a simple way the so-called Self-Consistent Screened Approximation (SCSA).Comment: p. 8, LATEX, DFF 193/9/199

Влияние акустических колебаний, генерируемых при трении, на изнашивание титановых сплавов

Представлены исследования изнашивания титановых сплавов в условиях гашения акустических колебаний возникающих при трении. Показано, что акустические колебания по своему действию аналогичны дополнительной эффективной нагрузке. Гашением акустических колебаний в трибосистеме можно влиять на механизм изнашивания и снижать износ титановых сплавов

Проблема социальных коммуникаций в контексте современных международных отношений

Исследована роль технологического аспекта социальных коммуникаций в современных международных отношениях. Показано, что информационные технологии, устранив барьеры коммуникаций, как во внутренней, так и международной жизни, сделали внешнюю политику крупных государств более сдержанной и ответственной

Synthesis of intermetallic hydrogen storage materials based on TI-CR by glow discharge plasma

The TiCr2 intermetallic compound with the C36 hexagonal Laves phase has been synthesized by glow discharge plasma. The hydrogen absorption-desorption properties of the obtained alloy were investigated. It is shown that hydrogen storage capacity of material was 0.43 wt % at 85 °C and 8 atm

ApoE polymorphisms in narcolepsy

BACKGROUND: Narcolepsy is a common neuropsychiatric disorder characterized by increased daytime sleepiness, cataplexy and hypnagogic hallucinations. Deficiency of the hypocretin neurotransmitter system was shown to be involved in the pathogenesis of narcolepsy in animals and men. There are several hints that neurodegeneration of hypocretin producing neurons in the hypothalamus is the pathological correlate of narcolepsy. The ApoE4 allele is a major contributing factor to early-onset neuronal degeneration in Alzheimer disease and other neurodegenerative diseases as well. METHODS: To clarify whether the ApoE4 phenotype predisposes to narcolepsy or associates with an earlier disease onset, we have genotyped the ApoE gene in 103 patients with narcolepsy and 101 healthy controls. RESULTS: The frequency of the E4 allele of the ApoE gene was 11% in the patient and 15% in the control groups. Furthermore, the mean age of onset did not differ between the ApoE4(+) and ApoE4(-) patient groups. CONCLUSION: Our results exclude the ApoE4 allele as a major risk factor for narcolepsy

3D Distribution of Molecular Gas in the Barred Milky Way

We present a new model of the three-dimensional distribution of molecular gas in the Milky Way Galaxy, based on CO line data. Our analysis is based on a gas-flow simulation of the inner Galaxy using smoothed-particle hydrodynamics (SPH) using a realistic barred gravitional potential derived from the observed COBE/DIRBE near-IR light distribution. The gas model prescribes the gas orbits much better than a simple circular rotation model and is highly constrained by observations, but it cannot predict local details. In this study, we provide a 3D map of the observed molecular gas distribution using the velocity field from the SPH model. A comparison with studies of the Galactic Center region suggests that the main structures are reproduced but somewhat stretched along the line-of-sight, probably on account of limited resolution of the underlying SPH simulation. The gas model will be publicly available and may prove useful in a number of applications, among them the analysis of diffuse gamma-ray emission as measured with GLAST.Comment: ApJ in pres