Spin-Hall nanooscillator based on an antiferromagnetic domain wall

We propose here a high-frequency spin-Hall nano-oscillator based on a simple magnetic texture, such as a domain wall, located in an antiferromagnet with easy-axis anisotropy type. We show that the spin current, polarized along the anisotropy axis, excites a conical precession of the N\'eel vector in such a domain wall, which allows obtaining a robust ac output signal, -- contrary to the planar precession in an uniform uniaxial antiferromagnet, where ac output is hard to achieve. The frequency of the auto-oscillations is easily tunable by the applied current up to the THz range, and the threshold current vanishes for pure uniaxial antiferromagnet. By micro-magnetic simulations, we demonstrate that the pinning of the domain wall is crucial for the oscillator design, which can be achieved in nano-constriction layout of the free layer.Comment: 7 pages, 5 figures. Brief explanation of the dynamics near the threshold is added at P.

Antiferromagnetic droplet soliton driven by spin current

We demonstrate that a spin current flowing through a nano-contact into a uniaxial antiferromagnet with first- and second-order anisotropy can excite a self-localized dynamic magnetic soliton, known as a spin-wave droplet in ferromagnets. The droplet nucleates at a certain threshold current with the frequency of the N\'eel vector precession laying below the antiferromagnetic resonance. The frequency exhibits nonlinear behavior with the increasing of applied current. At the high value of applied torque, the soliton mode transforms, and the oscillator emits spin waves propagating in the antiferromagnetic layer.Comment: 6 pages, 5 figure

Correlation Differences in Heartbeat Fluctuations During Rest and Exercise

We study the heartbeat activity of healthy individuals at rest and during exercise. We focus on correlation properties of the intervals formed by successive peaks in the pulse wave and find significant scaling differences between rest and exercise. For exercise the interval series is anticorrelated at short time scales and correlated at intermediate time scales, while for rest we observe the opposite crossover pattern -- from strong correlations in the short-time regime to weaker correlations at larger scales. We suggest a physiologically motivated stochastic scenario to explain the scaling differences between rest and exercise and the observed crossover patterns.Comment: 4 pages, 4 figure

The Modified Two-Factor Model of the Profitable Behavior of Households

The main aim of the publication is clarifying of the influence of the motivational-stimulating factor of forming the profitable behavior of households for its detailizing, taking attention of the characteristic features of specific households by adjusting the form and parameters of dynamic models. A logarithmic form of the quantitative-qualitative evaluation of the motivational-stimulating factor is proposed, based on the economic interpretation of the psycho-physiological Weber-Fechner’s law. The built motivation function allows coordinating of endogenous and exogenous features by means of setting the level of satisfaction with incomes ensuring the minimum needs of the household. Comparison of its dynamics depending on the level of incomes with dynamics if function of motivation, which value is determined by a linear deviation between the full «satisfaction» with incomes and the actual in percents, displayed the existence of plots with ultra high motivation that correspond to lower than the minimum that should be regarded as a manifestation of formation of the economic behaviour in crisis. The built model is characterized by limited rationality and corresponds to the theory of institutionalism

SOAR-OSIRIS observations of the Sh 2-307 HII region: Triggered star formation beyond the solar circle

This work aims to the study of the Sh 2-307 HII region and related stellar population. Near-infrared imaging and spectroscopic observations in the direction of Sh 2-307 were performed using OSIRIS at SOAR Telescope. From J-, H- and K-band spectra of the brightest source in the cluster, we conclude that it has a near-infrared spectra compatible with that taken for O9v-O9.5v stars. Using the derived spectral type and the respective J, H and K-band photometry, we compute a heliocentric distance of 3.2(0.5) kpc, which for R0 = 8 kpc, puts this cluster at more than 10 kpc from the Galactic centre. From the Brg, H2, and continuum narrow-band images we were able to detect both the NIR counterpart of the associated HII region, as well as, the interface between the ionised and the cool molecular gas. Using the 5 Ghz continuum flux density taken from the PMN catalogue and the Brg narrow band image we estimate that the HII region has a mean diameter of 0.94(0.15) pc, mean electron density of 550 cm-3 and an estimated dynamical age of 1.6 Myears years. The large fraction of sources presenting excess emission at 2micron suggests that the stellar population is very young, with many sources still in the pre-main sequence accreting phase. By the use of theoretical pre-main sequence tracks we derived a cluster mean age of about 2.5 Myears, and from the analyses of the fraction of excess emission sources as a function of their spatial distribution we found evidence for an age spread for the embedded pre-main sequence stellar population. Finally, from the study of the spatial distribution of the low-mass sources relative to the main-cluster source and associated photo-dissociation zones, we conclude that the O-type star probably has been triggering the star formation process in the region.Comment: 18 pages, 8 figures (three of them at lower resolution). Accepted by the MNRA

Galilean Conformal and Superconformal Symmetries

Firstly we discuss briefly three different algebras named as nonrelativistic (NR) conformal: Schroedinger, Galilean conformal and infinite algebra of local NR conformal isometries. Further we shall consider in some detail Galilean conformal algebra (GCA) obtained in the limit c equal to infinity from relativistic conformal algebra O(d+1,2) (d - number of space dimensions). Two different contraction limits providing GCA and some recently considered realizations will be briefly discussed. Finally by considering NR contraction of D=4 superconformal algebra the Galilei conformal superalgebra (GCSA) is obtained, in the formulation using complex Weyl supercharges.Comment: 16 pages, LateX; talk presented at XIV International Conference "Symmetry Methods in Physics", Tsakhkadzor, Armenia, August 16-22, 201

Специфика телесно ориентированного образования курсантов военного института

The article considers two models of somatic education which allow improving body condition of cadets taking into account diagnostic results of body condition at entering higher institution in order to achieve final appropriate result. The models are structured in different ways and influence body and psychological features of a cadet with a focus on his individual morphofunctional and psychological parameters. The author underlines that when a cadet feels deeply, understands and accepts personality values of physical training and at the same time he is engaged in sport activity and healthy lifestyle then it leads to great positive impact. The authors applied existing method approaches in combination of educational aspect, development one, upbringing aspect in the research. They also focused on phenomenon of health protection as “unity of recreation activities necessary for functional, physiological and valuable parameters of a person aimed at health protection”.Реферат. В статье рассмотрены модели системы соматического воспитания, позволяющие значительно улучшить физические кондиции курсантов, исходя из результатов диагностики физического состояния на входе, для достижения оптимального (акме) результата на выходе. Данные модели имеют разнообразную структуру построения цепи, воздействующую на физическую и психическую (телесную) составляющую организма курсанта с учетом его индивидуальных морфофункциональных и психологических особенностей. Положительный эффект будет достигнут, если личностные ценности физической культуры будут прочувствованы курсантом, поняты и осознаны как жизненно важные и необходимые, а ценностные ориентации будут подкрепляться активной физкультурноспортивной деятельностью и здоровым образом жизни. В процессе разработки модели авторы опирались на существующие методологические подходы к сочетанию образовательного, развивающего и воспитательного аспектов обучения, а также понимание феномена здоровьесбережения как «единства избирательно вовлеченных оздоровительных мероприятий, необходимых для качественных функциональных, физиологических, ценностных характеристик человека, взаимодействие и взаимоотношения которых направлены на сохранение здоровья»

The Casimir energy of skyrmions in the 2+1-dimensional O(3)-model

One-loop quantum corrections to the classical vortices in 2+1 dimensional O(3)-models are evaluated. Skyrme and Zeeman potential terms are used to stabilize the size of topological solitons. Contributions from zero modes, bound-states and scattering phase-shifts are calculated for vortices with winding index n=1 and n=2. For both cases the S-matrix shows a pronounced series of resonances for magnon-vortex scattering in analogy to the well-established baryon resonances in hadron physics, while vortices with n>2 are already classically unstable against decay. The quantum corrections destabilize the classically bound n=2 configuration. Approximate independence of the results with respect to changes in the renormalization scale is demonstrated.Comment: 24 pages LaTeX, 14 figure