Ion dynamics and acceleration in relativistic shocks

Ab-initio numerical study of collisionless shocks in electron-ion unmagnetized plasmas is performed with fully relativistic particle in cell simulations. The main properties of the shock are shown, focusing on the implications for particle acceleration. Results from previous works with a distinct numerical framework are recovered, including the shock structure and the overall acceleration features. Particle tracking is then used to analyze in detail the particle dynamics and the acceleration process. We observe an energy growth in time that can be reproduced by a Fermi-like mechanism with a reduced number of scatterings, in which the time between collisions increases as the particle gains energy, and the average acceleration efficiency is not ideal. The in depth analysis of the underlying physics is relevant to understand the generation of high energy cosmic rays, the impact on the astrophysical shock dynamics, and the consequent emission of radiation.Comment: 5 pages, 3 figure

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

Pedestal properties of H-modes with negative triangularity using the EPED-CH model

The EPED model has been designed to predict the pedestal height and width from a minimal set of parameters and using the stability of the pedestal region for global MHD peeling-ballooning (P-B) modes as well as local kinetic ballooning modes (KBMs). This approach has been validated for type-I ELMy H-modes and quiescent H-modes (QH) but can also be used for other types of H-modes where it usually sets an upper limit on the achievable pedestal height. Using the recently developed EPED-like model called EPED-CH and based on the equilibrium codes CHEASE and CAXE and the MHD stability code KINX, we investigate in this work the effect of negative triangularity on the pedestal structure. Our simulation results confirm the experimental results from TCV where a reduction of the pedestal height was observed when going from positive to negative top triangularity. This was interpreted as a degradation of the peeling-ballooning stability due to the closed access to the second stability region for ballooning modes in the case of negative triangularity. This effect is further enhanced by the coupling to the KBM stability criterion in EPED simulations. The novel concept of the negative triangularity tokamak (a DEMO-sized machine) is also investigated. Again a strong reduction of the pedestal height and width is observed going from positive to negative triangularity for upâdown symmetric equilibria. The pedestal height is also reduced going to more upâdown asymmetric cases. The beneficial effect of the global β value on the pedestal height, which is linked to the second stability access, is strongly reduced for negative triangularity

Multi-agent simulation of the processing shop

Multi-agent model is applied for the transformation of resources used for research companies or parts of companies in the presence of high load or idle assets in production, realized by means of the metallurgical enterprise information system. The following solution has been found as a result of experiments. There are needs in increase the number of heat-treatment furnaces and reduction the number of staff.Мультиагентная модель процесса преобразования ресурсов применяется для исследования предприятий или частей предприятий на наличие простоев или высокой загруженности средств в производстве, реализованной при помощи автоматизированной системы выпуска металлургической продукции. На основании построенной модели проведены эксперименты и представлены рекомендации по изменению анализируемых процессов: необходимо увеличить количество термических печей и снизить количество персонала цеха

Nonlinear Fourier Transform for Analysis of Coherent Structures in Dissipative Systems

Using the cubic Ginzburg-Landau equation as an example, we demonstrate how the inverse scattering transform can be applied to characterize coherent structures in dissipative nonlinear systems. Using this approach one can reduce the number of the effective degrees of freedom in the system when the dynamic is dominated by the coherent structures, even if they are embedded in the dispersive waves and demonstrate unstable behavior

Solitonic-exchange mechanism of surface~diffusion

We study surface diffusion in the framework of a generalized Frenkel-Kontorova model with a nonconvex transverse degree of freedom. The model describes a lattice of atoms with a given concentration interacting by Morse-type forces, the lattice being subjected to a two-dimensional substrate potential which is periodic in one direction and nonconvex (Morse) in the transverse direction. The results are used to describe the complicated exchange-mediated diffusion mechanism recently observed in MD simulations [J.E. Black and Zeng-Ju Tian, Phys. Rev. Lett. {\bf 71}, 2445-2448(1993)].Comment: 22 Revtex pages, 9 figures to appear in Phys. Rev.

Application of a decision support system in an industrial enterprise

Work at an industrial enterprise is associated with the constant adoption of management decisions at all levels, on which both the timeliness of order fulfilment and the efficiency of production capacity depend. The use of modern information technologies based on mathematical methods, allow you to make a decision knowing what should happen. © Published under licence by IOP Publishing Ltd.This work is supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006