630 research outputs found
Modular detector for deep underwater registration of muons and muon groups
Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences
Проблеми екологічної освіти студентів технічних університетів
The issue of the need to improve the quality of modern environmental education and training of technical universities students regarding of issues of productions environmental safety was considered. Because of the environmental burden increasing, it is impossible to solve the problems facing humanity without changing of the attitude of all mankind towards them.Розглянуто питання про необхідність підвищення якості сучасної екологічної освіти та підготовки студентів технічних університетів стосовно питань екологічної безпеки виробництв. Через зростаюче навантаження на навколишнє середовище неможливо вирішити проблеми, що стоять перед людством, не змінюючи відношення всього людства до них
Two-body problem in curved spacetime: exploring gravitational wave transient cases
We compare two versions of the GW150914 gravitational wave signal analysis by
the LIGO/Virgo collaboration. The first version was published in 2016 by this
collaboration along with their announcement of the first experimental detection
of gravitational waves. It was based on the gravitational wave waveforms with
the fully non-linear general-relativistic treatment of the coalescing two-body
problem. The second analysis of this signal by the same authors, published in
2017, was based on the quadrupole post-Newtonian (PN) flat spacetime
approximation of General Relativity. The authors had shown that the PN-based
mass estimation of the system coincide with that obtained by using rigorous
relativistic treatment in their first publication. In our view, this
coincidence implies that the rigorous non-linear theory for gravitational
waveforms of coalescing blackhole binaries does not fully account for the
difference between the source and detector reference frames - because the
PN-approximation, which is used for the comparison, does not make any
distinction between these two reference frames: by design and by the principles
and conditions for building the PN-approximation. We discuss possible
implications of this conflict and find that the accuracy of most of the
previously estimated characteristic (chirp) masses of coalescing binary
blackhole systems is likely to be affected by a substantial systematic error.
The corresponding luminosity distances of these sources also turn out to be
overestimated.Comment: 27 pages, 4 figures, 2 table
USAGE OF INTERVAL CAUSE-EFFECT RELATIONSHIP COEFFICIENTS IN THE QUANTITATIVE MODEL OF STRATEGIC PERFORMANCE
This paper proposes the method to obtain values of the coefficients of cause-effect relationships between strategic objectives in the form of intervals and use them in solving the problem of the optimal allocation of organization’s resources. We suggest taking advantage of the interval analytical hierarchy process for obtaining the ntervals. The quantitative model of strategic performance developed by M. Hell, S. Vidučić and Ž. Garača is employed for finding the optimal resource allocation. The uncertainty originated in the optimization problem as a result of interval character of the cause-effect relationship coefficients is eliminated through the application of maximax and maximin criteria. It is shown that the problem of finding the optimal maximin, maximax, and compromise resource allocation can be represented as a mixed 0-1 linear programming problem. Finally, numerical example and directions for further research are given
A panchromatic analysis of starburst galaxy M82: Probing the dust properties
(Abridged) We combine NUV, optical and IR imaging of the nearby starburst
galaxy M82 to explore the properties of the dust both in the interstellar
medium of the galaxy and the dust entrained in the superwind. The three NUV
filters of Swift/UVOT enable us to probe in detail the properties of the
extinction curve in the region around the 2175A bump. The NUV colour-colour
diagram strongly rules out a Calzetti-type law, which can either reflect
intrinsic changes in the dust properties or in the star formation history
compared to starbursts well represented by such an attenuation law. We
emphasize that it is mainly in the NUV region where a standard Milky-Way-type
law is preferred over a Calzetti law. The age and dust distribution of the
stellar populations is consistent with the scenario of an encounter with M81 in
the recent 400 Myr. The radial gradients of the NUV and optical colours in the
superwind region support the hypothesis that the emission in the wind cone is
driven by scattering from dust grains entrained in the ejecta. The observed
wavelength dependence reveals either a grain size distribution , where is the size of the grain, or a flatter distribution with a
maximum size cutoff, suggesting that only small grains are entrained in the
supernovae-driven wind.Comment: 12 pages, 12 figures, 3 tables, MNRAS, in pres
STUDY OF EXISTING MODES OF REDUCTIONS DURING PRODUCTION OF RAILWAY AXLES
Study of existing modes of reductions during production of railway axles
- …