372 research outputs found
The Cosmological Gene Project: cluster analysis of the atmospheric fluctuations on arcmin-scale imaging of the Cosmic Microwave Background
We discuss some aspects of the Cosmological Gene Project started at the
Special Astrophysical Observatory (Russia) in 1999. The goal of the project is
to measure the anisotropy and polarization of the Cosmic Microwave Background
(CMB) and investigation of atmospheric fluctuations and foreground on
arcmin-scales using the radio-telescope RATAN-600. We develop the cluster
analysis of one-dimensional random fields for the application to the RATAN-600
scans. We analyze the specific properties of peak clusterisation in the
RATAN-600 scans which to separate the primordial CMB signal from noise.Comment: Submitted to Astronomy & Astrophysic
Medical Students’ Reactive Anxiety as a Quality Criterion for Distance Learning during the SARS-COV-2 Pandemic
Background: Numerous studies have shown an effect of rapidly spreading SARS-COV-2 on combined anxiety-depressive disorders and maladjustment syndrome occurrences. Objective: To determine the primary medical students’ reactive anxiety level and the final scores of their educational progress in distance learning during the SARS-COV-2 pandemic. Materials and Methods: The study involved 824 students at medical universities in Saratov and Moscow. The assessment of the reactive anxiety level was carried out according to the State-Trait Anxiety Inventory, STAI; the average score of students' academic performance was calculated according to the data of the technological platform "1C: Enterprise" version 8.4.1. The survey was completed during distance learning in May 2020. The quality of distance learning was compared to a similar score for 2019, when students were trained in a traditional way. Statistical analysis was conducted using Statistica 6.0. Results: It was shown the presence of moderately severe disorders among the primary medical students according to the average score of reactive anxiety (43.28 ± 12.85), that expressed more in females s (p0.05) but the practical skills suffered much especially in time trend (p<0.05). Novelty: It was found that a high level of the reactive anxiety negatively affects the students' adaptive capabilities and the education quality. The specificity of programs at different faculties can determine the state of the students' psychological status. Findings:Timely transition to online classes during pandemics helps to preserve the students' mental well-being and the quality of the educational process. The duration of distance learning for a practical course should not exceed 25% of the whole course. Doi: 10.28991/esj-2021-SPER-07 Full Text: PD
УНИВЕРСАЛЬНЫЙ ВЕНТИЛЬНЫЙ РЕАКТИВНЫЙ ДВИГАТЕЛЬ С ПОСЛЕДОВАТЕЛЬНЫМ КОММУТАЦИОННЫМ БУФЕРОМ
In this paper, a power-supply circuit for a multipurpose switched reluctance motor with a series commutation buffer is presented. It is shown that a series buffer improves output characteristics of multipurpose switched reluctance motors under supply from a single-phase circuit and also lifts necessity of switching capacitors according to the motor power supply modes.В статье предложена схема питания универсального вентильного реактивного двигателя с последовательным коммутационным буфером. Показано, что использование последовательного коммутационного буфера улучшает выходные характеристики универсальных вентильных реактивных двигателей при питании от сети однофазного переменного тока, а так же устраняет необходимость переключения емкостей в зависимости от режима питания двигателя.У статті запропонована схема живлення універсального вентильного реактивного двигуна з послідовним комутаційним буфером. Показано, що використання послідовного комутаційного буфера покращує вихідні характеристики універсальних вентильних реактивних двигунів при живленні від мережі однофазного змінного струму, а також усуває необхідність переключення ємностей в залежності від режиму живлення двигуна
Providing energy decoupling of electric drive and electric grids for industrial electrical installations
Subjects of the research are industrial electric drives, witch maintain the operation of main actuating units of production machines and installations during the development of mineral resource deposits.
The goal is to research the possibility to ensure the energy decoupling of industrial electric drives and electric grid by means of structural implementation of active rectifiers into frequency converters. The main purpose of energy decoupling is to eliminate the negative impact of low quality electric energy and changes in energy parameters on electric drive operation.
In order to accomplish energy decoupling of electric drive with active rectifier, methods of mathematical and simulation modeling with mathematical application software package were used. The integrated simulation model with two electric drives, including active rectifier (energy decoupled electric drive) and diode rectifier (standard type electric drive), were created. Simulation model is provided with tools for oscillographic testing and analysis of the impact of power quality parameters on frequency converters and drive motors operation.
The analysis of effectiveness of energy decoupling by means of active rectifier of frequency converter shows that drive motor completely retains the stability and controllability of rotation frequency and torque during the changes of power quality parameters in electric grid. The use of active rectifier allows to ensure the operation of electric drive in required mode in case of voltage decrease by 30 % with normative value of 5-10 %, i.e. energy decoupling provides high stability margin for voltage. Electric drive with active rectifier ensures energy decoupling in case of asymmetry of supply voltage. The control of mechanical variables of induction motor during offsets in amplitude and frequency in all phases of electric grid is ensured to be on required level
Field theory of bicritical and tetracritical points. IV. Critical dynamics including reversible terms
This article concludes a series of papers (R. Folk, Yu. Holovatch, and G.
Moser, Phys. Rev. E 78, 041124 (2008); 78, 041125 (2008); 79, 031109 (2009))
where the tools of the field theoretical renormalization group were employed to
explain and quantitatively describe different types of static and dynamic
behavior in the vicinity of multicritical points. Here, we give the complete
two loop calculation and analysis of the dynamic renormalization-group flow
equations at the multicritical point in anisotropic antiferromagnets in an
external magnetic field. We find that the time scales of the order parameters
characterizing the parallel and perpendicular ordering with respect to the
external field scale in the same way. This holds independent whether the
Heisenberg fixed point or the biconical fixed point in statics is the stable
one. The non-asymptotic analysis of the dynamic flow equations shows that due
to cancelation effects the critical behavior is described - in distances from
the critical point accessible to experiments - by the critical behavior
qualitatively found in one loop order. Although one may conclude from the
effective dynamic exponents (taking almost their one loop values) that weak
scaling for the order parameter components is valid, the flow of the time scale
ratios is quite different and they do not reach their asymptotic values.Comment: 22 pages, 7 figures. Revised version, references updated, Fig. 5
modified, typos correcte
Gravitational Couplings of Intrinsic Spin
The gravitational couplings of intrinsic spin are briefly reviewed. A
consequence of the Dirac equation in the exterior gravitational field of a
rotating mass is considered in detail, namely, the difference in the energy of
a spin-1/2 particle polarized vertically up and down near the surface of a
rotating body is . Here is the latitude and
, where and are, respectively, the angular
momentum and radius of the body. It seems that this relativistic quantum
gravitational effect could be measurable in the foreseeable future.Comment: LaTeX file, no figures, 16 page
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance and Operation of the CMS Electromagnetic Calorimeter
The operation and general performance of the CMS electromagnetic calorimeter
using cosmic-ray muons are described. These muons were recorded after the
closure of the CMS detector in late 2008. The calorimeter is made of lead
tungstate crystals and the overall status of the 75848 channels corresponding
to the barrel and endcap detectors is reported. The stability of crucial
operational parameters, such as high voltage, temperature and electronic noise,
is summarised and the performance of the light monitoring system is presented
Commissioning and performance of the CMS silicon strip tracker with cosmic ray muons
This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPDuring autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);
Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,
and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT,
SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
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