1,027 research outputs found
Main results of the experiments conducted during the flight of the Kosmos-1129 Biosatellite and the status of preparation of studies on the next biosatllite
Experiments included studies on the biological effects of weightlessness. Space flight stress, disorientation, and physiological factors are discussed for each experimental subject. The subjects included rats, drosophila flies, and plants. Metabolic rates were monitored along with other changes in the subject's activity cycles
Spectroscopy of a fractional Josephson vortex molecule
In long Josephson junctions with multiple discontinuities of the Josephson
phase, fractional vortex molecules are spontaneously formed. At each
discontinuity point a fractional Josephson vortex carrying a magnetic flux
, Wb being the magnetic flux
quantum, is pinned. Each vortex has an oscillatory eigenmode with a frequency
that depends on and lies inside the plasma gap.
We experimentally investigate the dependence of the eigenfrequencies of a
two-vortex molecule on the distance between the vortices, on their topological
charge and on the bias current applied to the
Josephson junction. We find that with decreasing distance between vortices, a
splitting of the eigenfrequencies occurs, that corresponds to the emergence of
collective oscillatory modes of both vortices. We use a resonant microwave
spectroscopy technique and find good agreement between experimental results and
theoretical predictions.Comment: submitted to Phys. Rev.
Deterministic Josephson Vortex Ratchet with a load
We investigate experimentally a deterministic underdamped Josephson vortex
ratchet -- a fluxon-particle moving along a Josephson junction in an asymmetric
periodic potential. By applying a sinusoidal driving current one can compel the
vortex to move in a certain direction, producing average dc voltage across the
junction. Being in such a rectification regime we also load the ratchet, i.e.,
apply an additional dc bias current I_dc (counterforce) which tilts the
potential so that the fluxon climbs uphill due to the ratchet effect. The value
of the bias current at which the fluxon stops climbing up defines the strength
of the ratchet effect and is determined experimentally. This allows us to
estimate the loading capability of the ratchet, the output power and
efficiency. For the quasi-static regime we present a simple model which
delivers simple analytic expressions for the above mentioned figures of merit.Comment: submitted to PR
The World Conference on Dopingin Sport (4-7 November, Katowice, Poland)
The World Conference on Doping in Sport took place in Poland, Katowice from 4th to 7th of November 2019. WADA representatives and members of international sports federations, as well as more than 1500 delegates from all over the world, participated in the conference. Review of the anti-doping education of the past 20 years was summarized, perspectives for the future work were set
Relaxed blue ellipticals: accretion-driven stellar growth is a key evolutionary channel for low mass elliptical galaxies
How elliptical galaxies form is a key question in observational cosmology.
While the formation of massive ellipticals is strongly linked to mergers, the
low mass (Mstar < 10^9.5 MSun) regime remains less well explored. In
particular, studying elliptical populations when they are blue, and therefore
rapidly building stellar mass, offers strong constraints on their formation.
Here, we study 108 blue, low-mass ellipticals (which have a median stellar mass
of 10^8.7 MSun) at z < 0.3 in the COSMOS field. Visual inspection of extremely
deep optical HSC images indicates that less than 3 per cent of these systems
have visible tidal features, a factor of 2 less than the incidence of tidal
features in a control sample of galaxies with the same distribution of stellar
mass and redshift. This suggests that the star formation activity in these
objects is not driven by mergers or interactions but by secular gas accretion.
We combine accurate physical parameters from the COSMOS2020 catalog, with
measurements of local density and the locations of galaxies in the cosmic web,
to show that our blue ellipticals reside in low-density environments, further
away from nodes and large-scale filaments than other galaxies. At similar
stellar masses and environments, blue ellipticals outnumber their normal (red)
counterparts by a factor of 2. Thus, these systems are likely progenitors of
not only normal ellipticals at similar stellar mass but, given their high star
formation rates, also of ellipticals at higher stellar masses. Secular gas
accretion, therefore, likely plays a significant (and possibly dominant) role
in the stellar assembly of elliptical galaxies in the low mass regime.Comment: Published in MNRA
The morphological mix of dwarf galaxies in the nearby Universe
© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We use a complete, unbiased sample of 257 dwarf (10 8 M < M < 10 9.5 M) galaxies at z < 0.08, in the COSMOS field, to study the morphological mix of the dwarf population in low-density environments. Visual inspection of extremely deep optical images and their unsharp-masked counterparts reveals three principal dwarf morphological classes. 43 per cent and 45 per cent of dwarfs exhibit the traditional ‘early-type’ (elliptical/S0) and ‘late-type’ (spiral) morphologies, respectively. However, 10 per cent populate a ‘featureless’ class, that lacks both the central light concentration seen in early-types and any spiral structure – this class is missing in the massive-galaxy regime. 14 per cent, 27 per cent, and 19 per cent of early-type, late-type, and featureless dwarfs respectively show evidence for interactions, which drive around 20 per cent of the overall star formation activity in the dwarf population. Compared to their massive counterparts, dwarf early-types show a much lower incidence of interactions, are significantly less concentrated and share similar rest-frame colours as dwarf late-types. This suggests that the formation histories of dwarf and massive early-types are different, with dwarf early-types being shaped less by interactions and more by secular processes. The lack of large groups or clusters in COSMOS at z < 0.08, and the fact that our dwarf morphological classes show similar local density, suggests that featureless dwarfs in low-density environments are created via internal baryonic feedback, rather than by environmental processes. Finally, while interacting dwarfs can be identified using the asymmetry parameter, it is challenging to cleanly separate early and late-type dwarfs using traditional morphological parameters, such as ‘CAS’, M 20, and the Gini coefficient (unlike in the massive-galaxy regime).Peer reviewe
The model and the planning method of volume and variety assessment of innovative products in an industrial enterprise
In the long term, the innovative development strategy efficiency is considered as the most crucial condition for assurance of economic system competitiveness in market conditions. It determines the problem relevance of such justification strategies with regard to specific systems features and conditions of their operation. The problem solution for industrial enterprises can be based on mathematical models of supporting the decision-making on the elements of the innovative manufacturing program. An optimization model and the planning method of innovative products volume and variety are suggested. The feature of the suggested model lies in the nonlinear nature of the objective function. It allows taking into consideration the law of diminishing marginal utility. The suggested method of optimization takes into account the system features and enables the effective implementation of manufacturing capabilities in modern conditions of production organization and sales in terms of market saturation
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