1,065 research outputs found

    A nonstationary form of the range refraction parabolic equation and its application as an artificial boundary condition for the wave equation in a waveguide

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    The time-dependent form of Tappert's range refraction parabolic equation is derived using Daletskiy-Krein formula form noncommutative analysis and proposed as an artificial boundary condition for the wave equation in a waveguide. The numerical comparison with Higdon's absorbing boundary conditions shows sufficiently good quality of the new boundary condition at low computational cost.Comment: 12 pages, 9 figure

    Postnonclassical geography in Russia

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    We examine the new period of advancement of geography in the 21st century corresponding to the postnonclassical stage of advancement of science. The tendency toward interdisciplinary and problem-oriented research in contemporary geography is highlighted. The theoretical and practical significance of the evolution of geography at the postnonclassical period is demonstrated. Examples of contemporary geographical research corresponding to this period are given. © 2013 Pleiades Publishing, Ltd

    Probing Low Energy Neutrino Backgrounds with Neutrino Capture on Beta Decaying Nuclei

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    We study the interaction of low energy neutrinos on nuclei that spontaneously undergo beta decay showing that the product of the cross section times neutrino velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that decay via allowed transitions. The absence of energy threshold and the value of the cross section single out these processes as a promising though very demanding approach for future experiments aimed at a direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos.Comment: Includes a discussion of local relic neutrino density effect on neutrino capture rate. Accepted for publication in JCA

    Neutrino Properties Studied with a Triton Source Using Large TPC Detectors

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    The purpose of the present paper is to study the neutrino properties as they may appear in the low energy neutrinos emitted in triton decay, with maximum neutrino energy of 18.6 KeV. The technical challenges to this end can be summarized as building a very large TPC capable of detecting low energy recoils, down to a few 100 eV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos:1) The oscillation length involving the small mixing angle in the electronic neutrino disappearancei experiment is comparable to the length of the detector. Measuring the counting rate of neutrino-electron elastic scattering will give a precise measurement of the oscillation parameters free of systematic errors. First estimations show that a sensitivity of a few percent for the measurement of the above angle. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. We present results of theoretical calculation and studies of possible measurements.Comment: 30 LaTex pages and 9 figure

    Sensitivities of Low Energy Reactor Neutrino Experiments

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    The low energy part of the reactor neutrino spectra has not been experimentally measured. Its uncertainties limit the sensitivities in certain reactor neutrino experiments. The origin of these uncertainties are discussed, and the effects on measurements of neutrino interactions with electrons and nuclei are studied. Comparisons are made with existing results. In particular, the discrepancies between previous measurements with Standard Model expectations can be explained by an under-estimation of the low energy reactor neutrino spectra. To optimize the experimental sensitivities, measurements for \nuebar-e cross-sections should focus on events with large (>>1.5 MeV) recoil energy while those for neutrino magnetic moment searches should be based on events <<100 keV. The merits and attainable accuracies for neutrino-electron scattering experiments using artificial neutrino sources are discussed.Comment: 25 pages, 9 figure

    Optical Properties of Gel Titanium Dioxide Film, Modified By Metal Nanoparticles

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    The physic-chemical and optical properties of composite titanium dioxide films with gold, cobalt, copper, nickel and iron nanoparticles made using gel technology were studied in the work. The of titanium dioxide films structure synthesized according to different technologies is compared. The differential scanning calorimetry method was used to determine the temperatures of phase transitions of manufactured samples of various modifications of titanium dioxide. The transmission spectra of samples modified by metal nanoparticles with different concentrations were studied. Keywords: sol-gel, gel method, titanium dioxide, modification, nanoparticles, gold, cobalt, copper, iron, nickel, spectroscopy

    Three natural mechanical systems on Stiefel varieties

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    We consider integrable generalizations of the spherical pendulum system to the Stiefel variety V(n,r)=SO(n)/SO(n−r)V(n,r)=SO(n)/SO(n-r) for a certain metric. For the case of V(n,2) an alternative integrable model of the pendulum is presented. We also describe a system on the Stiefel variety with a four-degree potential. The latter has invariant relations on T∗V(n,r)T^*V(n,r) which provide the complete integrability of the flow reduced on the oriented Grassmannian variety G+(n,r)=SO(n)/SO(r)×SO(n−r)G^+(n,r)=SO(n)/SO(r)\times SO(n-r).Comment: 14 page

    Molecular-genetic aspects of the endometrium state on the day of the tentative implantation window in women with recurrent miscarriage in the programs of assisted reproductive technologies

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    Golovatyuk K. P., Nosenko O. M., Makshayeva E. T., Trofimov D. Yu., Donnikov A. E., Kolin V. V. Molecular-genetic aspects of the endometrium state on the day of the tentative implantation window in women with recurrent miscarriage in the programs of assisted reproductive technologies. Journal of Education, Health and Sport. 2017;7(9):621-626. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.1068361 http://ojs.ukw.edu.pl/index.php/johs/article/view/5076 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01.2017). 1223 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Authors 2017; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 15.08.2017. Revised: 20.09.2017. Accepted: 29.09.2017. MOLECULAR-GENETIC ASPECTS OF THE ENDOMETRIUM STATE ON THE DAY OF THE tentative IMPLANTATION WINDOW IN WOMEN WITH recurrent miscarriage IN THE PROGRAMS OF ASSISTED REPRODUCTIVE TECHNOLOGIES 1K. P. Golovatyuk, 2O. M. Nosenko, 1E. T. Makshayeva, 3D. Yu. Trofimov, 4A. E. Donnikov, 3V. V. Kolin 1Limited Liability Company Medical Center for Reproductive Health "Gameta", Odessa, Ukraine; 2Odessa National Medical University, Ukraine; 3Limited Liability Company "NPF DNA-Technology", Moscow, Russia; 4FGBU Scientific Center for Obstetrics, Gynecology and Perinatology. named after acad. V.I. Kulakov Ministry of Health care and Social Development of Russia, Moscow, Russia; e-mail: [email protected] Abstract More than 50% of pregnant women after the programs of assisted reproductive technologies (ART) face the problem of recurrent miscarriage (RMC), especially in the first trimester. Significant role in the development of RMC has infectious factor and chronic inflammation in the endometrium. The aim: to reveal the peculiarities of immune response mRNA genes of the inflammatory component expression in the period of the tentative implantation window (TIW) in women with RMC in ART programs. Material and methods. The main group consisted of 240 patients with RMC in ART programs; the control group included 100 conditionally healthy fertile women. On the ground of PCR reverse transcription, the mRNA of the IL-1β, IL-2, IL-10, Foxp3, TLR9, IL-2Rα cytokine genes was examined in endometrial samples obtained with the help of biopsy on the TIW day. Results. Analysis of the transcriptional profile of the immune response genes in the endometrium on TIW day revealed that the relative level of mRNA expression of the IL-1β, IL-2, Foxp3, TLR9, IL-2Rα genes did not differ significantly in the main and control groups. Statistically significant decrease in mRNA expression of IL-10 gene was observed in women with RPL. Conclusions. A feature of mRNA expression of the inflammatory component of the immune response in TIW period in women with RMC in ART programs is a decrease in the expression level of the IL-10 gene mRNA, which may be one of the reasons for the unfavorable outcomes of the onset pregnancy. Key words: recurrent miscarriage, assisted reproductive technologies, immune response, reverse transcription-polymerase chain reaction, tentative implantation window

    Neutrinos in a spherical box

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    In the present paper we study some neutrino properties as they may appear in the low energy neutrinos emitted in triton decay with maximum neutrino energy of 18.6 keV. The technical challenges to this end can be achieved by building a very large TPC capable of detecting low energy recoils, down to a a few tenths of a keV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos: 1) The oscillation length involving the small angle of the neutrino mixing matrix, directly measured in this disappearance experiment, is fully contained inside the detector. Measuring the counting rate of neutrino-electron elastic scattering as a function of the distance of the source will give a precise and unambiguous measurement of the oscillation parameters free of systematic errors. In fact first estimates show that even with a year's data taking a sensitivity of a few percent for the measurement of the above angle will be achieved. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. In this work we mainly focus on the various theoretical issues involved including a precise determination of the Weinberg angle at very low momentum transfer.Comment: 16 Pages, LaTex, 7 figures, talk given at NANP 2003, Dubna, Russia, June 23, 200

    Design and operation of a cryogenic charge-integrating preamplifier for the MuSun experiment

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    The central detector in the MuSun experiment is a pad-plane time projection ionization chamber that operates without gas amplification in deuterium at 31 K; it is used to measure the rate of the muon capture process μ−+d→n+n+νμ\mu^- + d \rightarrow n + n + \nu_\mu. A new charge-sensitive preamplifier, operated at 140 K, has been developed for this detector. It achieved a resolution of 4.5 keV(D2_2) or 120 e−e^- RMS with zero detector capacitance at 1.1 μ\mus integration time in laboratory tests. In the experimental environment, the electronic resolution is 10 keV(D2_2) or 250 e−e^- RMS at a 0.5 μ\mus integration time. The excellent energy resolution of this amplifier has enabled discrimination between signals from muon-catalyzed fusion and muon capture on chemical impurities, which will precisely determine systematic corrections due to these processes. It is also expected to improve the muon tracking and determination of the stopping location.Comment: 18 pages + title page, 13 figures, to be submitted to JINST; minor corrections, added one reference, updated author lis
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