805 research outputs found
Feasibility of study magnetic proximity effects in bilayer "superconductor/ferromagnet" using waveguide-enhanced Polarized Neutron Reflectometry
A resonant enhancement of the neutron standing waves is proposed to use in
order to increase the magnetic neutron scattering from a
"superconductor/ferromagnet"(S/F) bilayer. The model calculations show that
usage of this effect allows to increase the magnetic scattering intensity by
factor of hundreds. Aspects related to the growth procedure (order of
deposition, roughness of the layers etc) as well as experimental conditions
(resolution, polarization of the neutron beam, background etc) are also
discussed.
Collected experimental data for the S/F heterostructure
Cu(32nm)/V(40nm)/Fe(1nm)/MgO confirmed the presence of a resonant 60-fold
amplification of the magnetic scattering.Comment: The manuscript of the article submitted to Crysstalography Reports.
23 pages, 5 figure
Numerical simulation in roll pass design for bar rolling
The application of finite element simulation to the problem of roll pass design for round bar rolling is considered.
Two roll pass sequences were developed by analytical methods and then optimized using 2.5D Finite Element
Method (FEM). The first one is a classical oval-round roll pass design. The second one is a combination of flat rolls and
round roll passes. Relying on the simulation data obtained by FEM, the roll gaps were adjusted to achieve the required
bar shape and the uniform distribution of rolling force between the passes. Advantages and disadvantages
of each roll pass design were considered.Web of Science541787
Recovering rearranged cancer chromosomes from karyotype graphs
BACKGROUND: Many cancer genomes are extensively rearranged with highly aberrant chromosomal karyotypes. Structural and copy number variations in cancer genomes can be determined via abnormal mapping of sequenced reads to the reference genome. Recently it became possible to reconcile both of these types of large-scale variations into a karyotype graph representation of the rearranged cancer genomes. Such a representation, however, does not directly describe the linear and/or circular structure of the underlying rearranged cancer chromosomes, thus limiting possible analysis of cancer genomes somatic evolutionary process as well as functional genomic changes brought by the large-scale genome rearrangements. RESULTS: Here we address the aforementioned limitation by introducing a novel methodological framework for recovering rearranged cancer chromosomes from karyotype graphs. For a cancer karyotype graph we formulate an Eulerian Decomposition Problem (EDP) of finding a collection of linear and/or circular rearranged cancer chromosomes that are determined by the graph. We derive and prove computational complexities for several variations of the EDP. We then demonstrate that Eulerian decomposition of the cancer karyotype graphs is not always unique and present the Consistent Contig Covering Problem (CCCP) of recovering unambiguous cancer contigs from the cancer karyotype graph, and describe a novel algorithm CCR capable of solving CCCP in polynomial time. We apply CCR on a prostate cancer dataset and demonstrate that it is capable of consistently recovering large cancer contigs even when underlying cancer genomes are highly rearranged. CONCLUSIONS: CCR can recover rearranged cancer contigs from karyotype graphs thereby addressing existing limitation in inferring chromosomal structures of rearranged cancer genomes and advancing our understanding of both patient/cancer-specific as well as the overall genetic instability in cancer
Metal-free transannulation reaction of indoles with nitrostyrenes: a simple practical synthesis of 3-substituted 2-quinolones
3-Substituted 2-quinolones are obtained via a novel, metal-free transannulation reaction of 2-substituted indoles with 2-nitroalkenes in polyphosphoric acid. The reaction can be used in conjunction with the Fisher indole synthesis offering a practical three-component heteroannulation methodology to produce 2-quinolones from arylhydrazines, 2-nitroalkenes and acetophenone
On the feasibility to study inverse proximity effect in a single S/F bilayer by Polarized Neutron Reflectometry
Here we report on a feasibility study aiming to explore the potential of
Polarized Neutron Reflectometry (PNR) for detecting the inverse proximity
effect in a single superconducting/ferromagnetic bilayer. Experiments,
conducted on the V(40nm)/Fe(1nm) S/F bilayer, have shown that experimental spin
asymmetry measured at T = 0.5TC is shifted towards higher Q values compared to
the curve measured at T = 1.5TC. Such a shift can be described by the
appearance in superconducting vanadium of magnetic sub-layer with thickness of
7 nm and magnetization of +0.8 kG.Comment: Changes in the 2nd version: small mistypes are corrected. Manuscript
submitted to JETP let. 4 pages, 2 figure
Method of Laser Cross-correlation Optical Spectroscopy for Investigation of Dispersion Medium
In the paper, we suggest one of the possible schemes of a cross-correlation optical spectroscopicdevice for investigation of turbid colloidal solutions and suspensions. This devise is designed fordeterminationof the hydrodynamic radii of nanoparticles. The cross-correlation function is constructed for two signals of light intensity scattered on a cuvette with the investigated dispersion medium. The construction of crosscorrelation optical spectroscopicdevice makes it possible to detect single scattered light by suppressing multiple scattering. We carried out an analysis of literature containing theory of light scattering and results of applying cross-correlation method for investigation of solutions and suspensions. Based on the analytical review, the scheme of cross-correlation optical spectroscopicdevice was developed and constructed.
Keywords: specklefield, cross-correlation, optical spectroscopy, size distribution, dispersion mediu
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