113 research outputs found
Integrated Supply Chain Strategy with Standardization of Professional Communication as Lean Manufacturing Tool
Abstract-The article substantiates the importance of professional communication standardization and supply chain strategy as lean manufacturing tool, which is loss reduction reserve in the organizations of different fields. They consider the issues of organization effectiveness impact in the field of communication processes, and the effectiveness of its work in general. They provided the definition of professional communication standardization process, the main conditions for its occurrence are highlighted. The formation of lean communication is proposed as the result of professional communication standardization. They summarized the advantages of standardized professional communication gained by the company
Extremely polysubstituted magnetic material based on magnetoplumbite with a hexagonal structure: Synthesis, structure, properties, prospects
Crystalline high-entropy single-phase products with a magnetoplumbite structure with grains in the µm range were obtained using solid-state sintering. The synthesis temperature was up to 1400 °C. The morphology, chemical composition, crystal structure, magnetic, and electrodynamic properties were studied and compared with pure barium hexaferrite BaFe 12 O 19 matrix. The polysubstituted high-entropy single-phase product contains five doping elements at a high concentration level. According to the EDX data, the new compound has a formula of Ba(Fe6Ga1.25In1.17Ti1.21Cr1.22Co1.15)O19. The calculated cell parameter values were a = 5.9253(5) Å, c = 23.5257(22) Å, and V = 715.32(9) Å3. The increase in the unit cell for the substituted sample was expected due to the different ionic radius of Ti/In/Ga/Cr/Co compared with Fe3+. The electrodynamicmeasurements were performed. The dielectric and magnetic permeabilities were stable in the frequency range from 2 to 12 GHz. In this frequency range, the dielectric and magnetic losses were??0.2/0.2. Due to these electrodynamic parameters, this material can be used in the design of microwave strip devices. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The work was supported by the Russian Science Foundation, project No. 18-73-10049
Inertial mechanism: dynamical mass as a source of particle creation
A kinetic theory of vacuum particle creation under the action of an inertial
mechanism is constructed within a nonpertrubative dynamical approach. At the
semi-phenomenological level, the inertial mechanism corresponds to quantum
field theory with a time-dependent mass. At the microscopic level, such a
dependence may be caused by different reasons: The non-stationary Higgs
mechanism, the influence of a mean field or condensate, the presence of the
conformal multiplier in the scalar-tensor gravitation theory etc. In what
follows, a kinetic theory in the collisionless approximation is developed for
scalar, spinor and massive vector fields in the framework of the oscillator
representation, which is an effective tool for transition to the quasiparticle
description and for derivation of non-Markovian kinetic equations. Properties
of these equations and relevant observables (particle number and energy
densities, pressure) are studied. The developed theory is applied here to
describe the vacuum matter creation in conformal cosmological models and
discuss the problem of the observed number density of photons in the cosmic
microwave background radiation. As other example, the self-consistent evolution
of scalar fields with non-monotonic self-interaction potentials (the
W-potential and Witten - Di Vecchia - Veneziano model) is considered. In
particular, conditions for appearance of tachyonic modes and a problem of the
relevant definition of a vacuum state are considered.Comment: 51 pages, 18 figures, submitted to PEPAN (JINR, Dubna); v2: added
reference
A kinetic approach to eta' production from a CP-odd phase
The production of (eta,eta')- mesons during the decay of a CP-odd phase is
studied within an evolution operator approach. We derive a quantum kinetic
equation starting from the Witten-DiVecchia-Veneziano Lagrangian for
pseudoscalar mesons containing a U_A(1) symmetry breaking term. The non-linear
vacuum mean field for the flavour singlet pseudoscalar meson is treated as a
classical, self-interacting background field with fluctuations assumed to be
small. The numerical solution provides the time evolution of momentum
distribution function of produced eta'- mesons after a quench at the
deconfinement phase transition. We show that the time evolution of the momentum
distribution of the produced mesons depend strongly on the shape of the
effective potential at the end of the quench, exhibiting either parametric or
tachyonic resonances. Quantum statistical effects are essential and lead to a
pronounced Bose enhancement of the low momentum states.Comment: 10 pages, latex, epsfig, 6 figure
Pair Creation and an X-ray Free Electron Laser
Using a quantum kinetic equation coupled to Maxwell's equation we study the
possibility that focused beams at proposed X-ray free electron laser facilities
can generate electric field strengths large enough to cause spontaneous
electron-positron pair production from the QED vacuum. Our approach yields the
time and momentum dependence of the single particle distribution function.
Under conditions reckoned achievable at planned facilities, repeated cycles of
particle creation and annihilation take place in tune with the laser frequency.
However, the peak particle number density is insensitive to this frequency and
one can anticipate the production of a few hundred particle pairs per laser
period. Field-current feedback and quantum statistical effects are small and
can be neglected in this application of non-equilibrium quantum mean field
theory.Comment: 4 pages, LaTeX2
BBGKY kinetic approach for an e-e+gamma plasma created from the vacuum in a strong laser-generated electric field: The one-photon annihilation channel
In the present work a closed system of kinetic equations is obtained from the
truncation of the BBGKY hierarchy for the description of the vacuum creation of
an electron - positron plasma and secondary photons due to a strong laser
field. This truncation is performed in the Markovian approximation for the
one-photon annihilation channel which is accessible due to the presence of the
strong external field. Estimates of the photon production rate are obtained for
different domains of laser field parameters (frequency nu and field strength
E). A huge quantity of optical photons of the quasiclassical laser field is
necessary to satisfy the conservation laws of energy and momentum of the
constituents (e-, e+, gamma) in this channel. Since the number of these optical
photons corresponds to the order of perturbation theory, a vanishingly small
photon production rate results for the optical region and strongly subcritical
fields E << E_c. In the gamma-ray region nu <~ m the required number of laser
photons is small and the production rate of photons from the one-photon
annihilation process becomes accessible to observations for subcritical fields
E <~ E_c. In the infrared region the photon distribution has a 1/k spectrum
typical for flicker noise.Comment: 14 pages, 1 figure, one reference with referring text added and one
citation correcte
Self - Consistent Description of e+e-gamma Plasma Created from the Vacuum in a Strong Electric Laser Field
In the present work a closed system of kinetic equations is obtained for the
description of the vacuum creation of an electron - positron plasma and
secondary photons due to a strong laser field. An estimate for the photon
energy distribution is obtained. In the Markovian approximation the photon
distribution has a 1/k spectrum (flicker noise).Comment: 6 pages, contribution to Proceedings of the International Bogolyubov
Conference, Dubna (Russia), August 21-27, 200
The effect of heat treatment on the microstructure and mechanical properties of 2d nanostructured au/nife system
Nanostructured NiFe film was obtained on silicon with a thin gold sublayer via pulsed electrodeposition and annealed at a temperature from 100 to 400◦C in order to study the effect of heat treatment on the surface microstructure and mechanical properties. High-resolution atomic force microscopy made it possible to trace stepwise evolving microstructure under the influence of heat treatment. It was found that NiFe film grains undergo coalescence twice—at ~100 and ~300°C—in the process of a gradual increase in grain size. The mechanical properties of the Au/NiFe nanostructured system have been investigated by nanoindentation at two various indentation depths, 10 and 50 nm. The results showed the opposite effect of heat treatment on the mechanical properties in the near-surface layer and in the material volume. Surface homogenization in combination with oxidation activation leads to abnormal strengthening and hardening-up of the near-surface layer. At the same time, a nonlinear decrease in hardness and Young’s modulus with increasing temperature of heat treatment characterizes the internal volume of nanostructured NiFe. An explanation of this phenomenon was found in the complex effect of changing the ratio of grain volume/grain boundaries and increasing the concentration of thermally activated diffuse gold atoms from the sublayer to the NiFe film. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0011
The High-Spin State of Fe Ions in SrFe12O19 Hexaferrites
The high-spin state of Fe ions was detected in SrFe12O19 by X-ray emission X-ray spectroscopy.Работа выполнена при поддержке РФФИ № 20-02-00541 А
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