Radiation of electrons in Weibel-generated fields: a general case

Weibel instability turns out to be the a ubiquitous phenomenon in High-Energy Density environments, ranging from astrophysical sources, e.g., gamma-ray bursts, to laboratory experiments involving laser-produced plasmas. Relativistic particles (electrons) radiate in the Weibel-produced magnetic fields in the Jitter regime. Conventionally, in this regime, the particle deflections are considered to be smaller than the relativistic beaming angle of 1/$\gamma$ ($\gamma$ being the Lorentz factor of an emitting particle) and the particle distribution is assumed to be isotropic. This is a relatively idealized situation as far as lab experiments are concerned. We relax the assumption of the isotropy of radiating particle distribution and present the extension of the jitter theory amenable for comparisons with experimental data.Comment: Proceedings of International Conference on HEDP/HEDLA-0

Can Cluster Evaporation Explain the Missing Thermal Energy in Galaxy Clusters?

Resent observations of a number of galaxy clusters using the Sunyaev-Zel'dovich effect indicate that about 1/3 of baryonic mass is missing from the hot intracluster medium (ICM), which is significantly larger than the fraction of stars and cool gas, which account for only about 10%. Here we address the question whether the remaining $22\pm10$ can be accounted for by thermal evaporation of gas from clusters. We have found that evaporation can occur only from the cluster ``surface'', $r\sim r_{\rm vir}$, and not from it's interior. We evaluated particle diffusion through the magnetized ICM for several scenarios of ISM turbulence and found that diffusivity is suppressed by at least a factor of 100 or more, compared to the Spitzer value. Thus, only particles from radii r\ga0.9r_{\rm vir} can evaporate. Diffusion of particles from inside the cluster, r\la0.9r_{\rm vir}, takes longer than the Hubble time. This lowers the cluster-averaged fraction of the evaporated hot gas to few percent or less. However, if the missing hot component {\it is indeed} due to evaporation, this strongly constrains the magnetic field structure in the cluster envelope, namely either (i) the gas is completely unmagnetized ($B\le10^{-21}$ gauss) in the cluster halo or (ii) the magnetic fields in the ICM are rather homogeneous and non-turbulent.Comment: ApJL, accepted version; 4 pages, 2 figure

Ab initio exchange interactions and magnetic properties of Gd2Fe17 iron sublattice: rhombohedral vs. hexagonal phases

In the framework of the LSDA+U method electronic structure and magnetic properties of the intermetallic compound Gd2Fe17 for both rhombohedral and hexagonal phases have been calculated. On top of that, ab initio exchange interaction parameters within the Fe sublattice for all present nearest and some next nearest Fe ions have been obtained. It was found that for the first coordination sphere direct exchange interaction is ferromagnetic. For the second coordination sphere indirect exchange interaction is observed to be weaker and of antiferromagnetic type. Employing the theoretical values of exchange parameters Curie temperatures Tc of both hexagonal and rhombohedral phases of Gd2Fe17 within Weiss mean-field theory were estimated. Obtained values of Tc and its increase going from the hexagonal to rhombohedral crystal structure of Gd2Fe17 agree well with experiment. Also for both structures LSDA+U computed values of total magnetic moment coincide with experimental ones.Comment: 20 pages, 2 figures; V2 as published in PR

Comparative analysis of order allocation methods and intelligent systems for effective download of production capacities of manufacturing enterprise

The article compares the planning systems of the enterprise, determines their opportunities to use simulation for the process of distribution of production orders. A comparative review of the methods used in production planning systems and the multi-agent approach in solving the problem of the allocation of production orders is carried out. The possibility of approaches in cases when it is impossible to perform production tasks within the established time frame is considered, as well as to effectively load the available capacities of the units. In case it is not possible to produce the necessary quantity to distribute the part to another, similar to the type of equipment used, but different from it by the quantity and production capacity of the unit. Transmission must be carried out under the condition of sufficient capacity in the subdivision. The results of theoretical and experimental studies are presented. In the process of work, we used the BPsim. MAS dynamic modeling system. An automated system with the possibility of using simulation for the allocation of production orders is considered. © 2019 IOP Publishing Ltd. All rights reserved.The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006

Surface Electronic Structures and Field Emission Currents at Sodium Overlayers on Low-Index Tungsten Surfaces

The total energy distributions (TEDs) of the emission currents in field emission and surface photofield emission and the overlayer-induced modifications in the surface electronic structures from the technologically important W surfaces with the commensurate W(100)/Na c(2x2), W(110)/Na (2x2) and W(111)/Na (1x1) overlayers are calculated. The TEDs obtained by our recent numerical method that extends the full-potential linear augmented plane wave method for the electronic structures to the study of field and photofield emission are used to interpret the shifts of the peaks in the experimental TEDs in field emission and photofield emission from the W(100) and W(110) surfaces at sub-monolayer and monolayer Na coverage. Hybridization of the 3s Na states with the pairs of dz2-like surface states of the strong Swanson hump in clean W(100) and surface resonances in clean W(111) below the Fermi energy shifts these W states by about -1.2 eV and -1.0 eV, thus stabilizing these states, to yield new strong peaks in the TEDs in field emission and photofield emission from W(100)/Na c(2x2) and W(111)/Na (1x1) respectively. The effect of Na intralayer interactions are discussed and are shown to shift the strong s- and p-like peaks in the surface density of states of W(110) below and above the Fermi energy respectively to lower energy with increased Na coverage, in agreement with experiments.Comment: 12 page

Randomized controlled trial comparing laparoscopic greater curvature plication versus laparoscopic sleeve gastrectomy

Laparoscopic greater curvature plication (LGCP) is a new restrictive bariatric procedure, which has a similar restrictive mechanism like laparoscopic sleeve gastrectomy (LSG) without potential risk of leak. Aim of the study was to compare 2-year outcomes of LSG and LGCP. Multicenter prospective randomized trial was started in 2010. A total of 54 patients with morbid obesity were allocated either to LGCP group (n = 25) or LSG group (n = 27). Main exclusion criteria were: ASA [III, age[75 and BMI [65 kg/m2 . There were 40 women and 12 men, and the mean age was 42.6 ± 6.8 years (range 35–62). Data on the operation time, complications, hospital stay, body mass index loss, percentage of excess weight loss (%EWL), loss of appetite and improvement in comorbidities were collected during the follow-up examinations. All procedures were completed laparoscopically. The mean operative time was 92.0 ± 15 min for LSG and 73 ± 19 min for LGCP (p[0.05). The mean hospital stay was 4.0 ± 1.9 days in the LSG group and 3.8 ± 1.7 days in LGCP group (p[0.05). One year after surgery, the mean %EWL was 59.5 ± 15.4 % in LSG group and 45.8 ± 17 % in LGCP group (p[0.05). After 2 years, mean %EWL was 78.9 ± 20 % in the LSG group and 42.4 ± 18 % in the LGCP group (p\0.01). After 3 years, mean %EWL was 72.8 ± 22 in the LSG group and only 20.5 ± 23.9 in the LGCP group (p\0.01). Loss of feeling of hunger after 2 years was 25 % in LGCP group and 76.9 % in the LSG group (p\0.05). The comorbidities including diabetes, sleep apnea and hypertension were markedly improved in the both groups after surgery. The short-term outcomes demonstrated equal effectiveness of the both procedures, but 2-year follow-up showed that LGCP is worse than LSG as a restrictive procedure for weight loss

Time of life as it is in LiFeAs

The time of life of fermionic quasiparticles, the distribution of which in the momentum-energy space can be measured by angle resolved photoemission (ARPES), is the first quantity to look for fingerprints of interaction responsible for the superconducting pairing. Such an approach has been recently used for superconducting cuprates, but its direct application to pnictides was not possible due to essential three-dimensionality of the electronic band structure and magnetic ordering. Here, we report the investigation of the quasiparticle lifetime in LiFeAs, a non-magnetic stoichiometric superconductor with a well separated two-dimensional band. We have found two energy scales: the lower one contains clear fingerprints of optical phonon modes while the higher scale indicates a presence of strong electron-electron interaction. The result suggests that LiFeAs is a phonon mediated superconductor with strongly enhanced electronic density of states at the Fermi level.Comment: reevaluated electron-phonon coupling strength, added reference

The study of the proton-proton collisions at the beam momentum 1628 MeV/c

The detailed investigation of the single pion production reactions $pp\to pn\pi^{+}$ and $pp\to pp\pi^{o}$ at the incident proton momentum 1628 MeV/c has been carried out. The data are analyzed in the framework of the event-by-event maximum likelihood method together with the $pp\to pp\pi^{0}$ data measured earlier in the energy region below 1 GeV. At 1628 MeV/c the largest contributions stem from the $^{3}P_{2}$, $^{3}P_{1}$, $^{3}P_{0}$, $^{1}D_{2}$ and $^{3}F_{2}$ initial partial waves.Comment: 7 pages, 9 figure