41 research outputs found
Investigation the effect of heteroatomic compounds in diesel fuel on the effectiveness of depressors
Graded associative conformal algebras of finite type
In this paper, we consider graded associative conformal algebras. The class
of these objects includes pseudo-algebras over non-cocommutative Hopf algebras
of regular functions on some linear algebraic groups. In particular, an
associative conformal algebra which is graded by a finite group is a
pseudo-algebra over the coordinate Hopf algebra of a linear algebraic group
such that the identity component is the affine line and . A classification of simple and semisimple graded associative
conformal algebras of finite type is obtained
SDiff(2) Toda equation -- hierarchy, function, and symmetries
A continuum limit of the Toda lattice field theory, called the SDiff(2) Toda
equation, is shown to have a Lax formalism and an infinite hierarchy of higher
flows. The Lax formalism is very similar to the case of the self-dual vacuum
Einstein equation and its hyper-K\"ahler version, however now based upon a
symplectic structure and the group SDiff(2) of area preserving diffeomorphisms
on a cylinder . An analogue of the Toda lattice tau function is
introduced. The existence of hidden SDiff(2) symmetries are derived from a
Riemann-Hilbert problem in the SDiff(2) group. Symmetries of the tau function
turn out to have commutator anomalies, hence give a representation of a central
extension of the SDiff(2) algebra.Comment: 16 pages (``vanilla.sty" is attatched to the end of this file after
``\bye" command
Hierarchical structure of cascade of primary and secondary periodicities in Fourier power spectrum of alphoid higher order repeats
<p>Abstract</p> <p>Background</p> <p>Identification of approximate tandem repeats is an important task of broad significance and still remains a challenging problem of computational genomics. Often there is no single best approach to periodicity detection and a combination of different methods may improve the prediction accuracy. Discrete Fourier transform (DFT) has been extensively used to study primary periodicities in DNA sequences. Here we investigate the application of DFT method to identify and study alphoid higher order repeats.</p> <p>Results</p> <p>We used method based on DFT with mapping of symbolic into numerical sequence to identify and study alphoid higher order repeats (HOR). For HORs the power spectrum shows equidistant frequency pattern, with characteristic two-level hierarchical organization as signature of HOR. Our case study was the 16 mer HOR tandem in AC017075.8 from human chromosome 7. Very long array of equidistant peaks at multiple frequencies (more than a thousand higher harmonics) is based on fundamental frequency of 16 mer HOR. Pronounced subset of equidistant peaks is based on multiples of the fundamental HOR frequency (multiplication factor <it>n </it>for <it>n</it>mer) and higher harmonics. In general, <it>n</it>mer HOR-pattern contains equidistant secondary periodicity peaks, having a pronounced subset of equidistant primary periodicity peaks. This hierarchical pattern as signature for HOR detection is robust with respect to monomer insertions and deletions, random sequence insertions etc. For a monomeric alphoid sequence only primary periodicity peaks are present. The 1/<it>f</it><sup><it>β </it></sup>– noise and periodicity three pattern are missing from power spectra in alphoid regions, in accordance with expectations.</p> <p>Conclusion</p> <p>DFT provides a robust detection method for higher order periodicity. Easily recognizable HOR power spectrum is characterized by hierarchical two-level equidistant pattern: higher harmonics of the fundamental HOR-frequency (secondary periodicity) and a subset of pronounced peaks corresponding to constituent monomers (primary periodicity). The number of lower frequency peaks (secondary periodicity) below the frequency of the first primary periodicity peak reveals the size of <it>n</it>mer HOR, i.e., the number <it>n </it>of monomers contained in consensus HOR.</p
Source of polarised deuterons
The proposed project assumes the development of a universal high-intensity source of polarized deuterons (protons) using a charge-exchange
plasma ionizer. The design output current of the source will be up to 10 mA
for and polarization will be up
to of the maximal vector () and tensor (+1,-2) polarization.
The project is based on the equipment which was supplied within the framework
of an agreement between JINR and IUCF (Bloomington, USA). The project will be
realized in close cooperation with INR (Moscow, Russia). The source will be
installed in the linac hall (LU-20) and polarization of beams will be measured
at the output of LU-20. The main purpose of the project is to increase the
intensity of the accelerated polarized beams at the JINR Accelerator Complex up
to 1010 d/pulse. Calculations and first accelerator runs have shown that
the depolarization resonances are absent for the deuteron beam in the entire
energy range of the NUCLOTRON. The source could be transformed into a source of
polarized negative ions if necessary. The period of reliable operation without
participation of the personnel should be within 1000 hours. The project should
be implemented within two to two and a half years from the start of funding