306 research outputs found
The New Sensing Fibre for Application in Optical Fibre Current Sensor
The present paper deals with investigations concerning optical fibre current sensors. They are mainly applied in measurements of the intensity of the electric current in the power lines as so-called optical transformers of the electrical current. The most important advantages of fibre current sensors are: safety of service, insulating power as well as their insensitiveness to electromagnetic interference. The investigations were concentrated on designing of adequate sensing fibre, and particularly on the choice of an adequate kind of glass, of which this fibre could be made. Besides, also the head of the fibre current sensor was designed, basing on the suggested and produced sensing fibre. The paper presents the results of magneto-optic tests of the glass and the sensing fibre
Work fluctuations in quantum spin chains
We study the work fluctuations of two types of finite quantum spin chains
under the application of a time-dependent magnetic field in the context of the
fluctuation relation and Jarzynski equality. The two types of quantum chains
correspond to the integrable Ising quantum chain and the nonintegrable XX
quantum chain in a longitudinal magnetic field. For several magnetic field
protocols, the quantum Crooks and Jarzynski relations are numerically tested
and fulfilled. As a more interesting situation, we consider the forcing regime
where a periodic magnetic field is applied. In the Ising case we give an exact
solution in terms of double-confluent Heun functions. We show that the
fluctuations of the work performed by the external periodic drift are maximum
at a frequency proportional to the amplitude of the field. In the nonintegrable
case, we show that depending on the field frequency a sharp transition is
observed between a Poisson-limit work distribution at high frequencies toward a
normal work distribution at low frequencies.Comment: 10 pages, 13 figure
Current large deviations in a driven dissipative model
We consider lattice gas diffusive dynamics with creation-annihilation in the
bulk and maintained out of equilibrium by two reservoirs at the boundaries.
This stochastic particle system can be viewed as a toy model for granular gases
where the energy is injected at the boundary and dissipated in the bulk. The
large deviation functional for the particle currents flowing through the system
is computed and some physical consequences are discussed: the mechanism for
local current fluctuations, dynamical phase transitions, the
fluctuation-relation
Test of the photon detection system for the LHCb RICH Upgrade in a charged particle beam
The LHCb detector will be upgraded to make more efficient use of the
available luminosity at the LHC in Run III and extend its potential for
discovery. The Ring Imaging Cherenkov detectors are key components of the LHCb
detector for particle identification. In this paper we describe the setup and
the results of tests in a charged particle beam, carried out to assess
prototypes of the upgraded opto-electronic chain from the Multi-Anode PMT
photosensor to the readout and data acquisition system.Comment: 25 pages, 22 figure
Molecular architecture of the Jumonji C family histone demethylase KDM5B
Abstract The full length human histone 3 lysine 4 demethylase KDM5B (PLU-1/Jarid1B) has been studied using Hydrogen/Deuterium exchange mass spectrometry, homology modelling, sequence analysis, small angle X-ray scattering and electron microscopy. This first structure on an intact multi-domain Jumonji histone demethylase reveal that the so-called PLU region, in the central region of KDM5B, has a curved α-helical three-dimensional structure, that acts as a rigid linker between the catalytic core and a region comprising four α-helices, a loop comprising the PHD2 domain, two large intrinsically disordered loops and the PHD3 domain in close proximity. The dumbbell shaped and curved KDM5B architecture observed by electron microscopy is complementary to the nucleosome surface and has a striking overall similarity to that of the functionally related KDM1A/CoREST complex. This could suggest that there are similarities between the demethylation mechanisms employed by the two histone 3 lysine 4 demethylases at the molecular level
Measurements of , K, p and spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS
Measurements of inclusive spectra and mean multiplicities of ,
K, p and produced in inelastic p+p interactions at
incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ( 6.3,
7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super
Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer.
Spectra are presented as function of rapidity and transverse momentum and are
compared to predictions of current models. The measurements serve as the
baseline in the NA61/SHINE study of the properties of the onset of
deconfinement and search for the critical point of strongly interacting matter
Observation of associated production of a boson with a meson in the~forward region
A search for associated production of a boson with an open charm meson is
presented using a data sample, corresponding to an integrated luminosity of
of proton--proton collisions at a centre-of-mass energy
of 7\,TeV, collected by the LHCb experiment. %% Seven candidate events for
associated production of a boson with a meson and four candidate
events for a boson with a meson are observed with a combined
significance of 5.1standard deviations. The production cross-sections in the
forward region are measured to be where the first uncertainty is statistical and the
second systematic.Comment: 18 pages, 2 figure
Measurements of the , , meson and baryon lifetimes
Measurements of -hadron lifetimes are reported using collision data,
corresponding to an integrated luminosity of 1.0fb, collected by the
LHCb detector at a centre-of-mass energy of Tev. Using the exclusive decays
, , ,
and the average decay
times in these modes are measured to be = 0.004 0.003 ps, =
0.006 0.004 ps, = 0.013
0.005 ps, = 0.027
0.006 ps and = 0.011
0.005 ps, where the first uncertainty is statistical and the second is
systematic. These represent the most precise lifetime measurements in these
decay modes. In addition, ratios of these lifetimes, and the ratio of the
decay-width difference, , to the average width, , in
the system, , are
reported. All quantities are found to be consistent with Standard Model
expectations.Comment: 28 pages, 4 figures. Updated reference
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