Large time asymptotics for the Grinevich-Zakharov potentials

In this article we show that the large time asymptotics for the Grinevich-Zakharov rational solutions of the Novikov-Veselov equation at positive energy (an analog of KdV in 2+1 dimensions) is given by a finite sum of localized travel waves (solitons)

Absence of exponentially localized solitons for the Novikov--Veselov equation at negative energy

International audienceWe show that Novikov--Veselov equation (an analog of KdV in dimension 2 + 1) does not have exponentially localized solitons at negative energy

States localized on a boundary of the time-dependent parity-breaking medium

We consider the massive vector field propagating in the inhomogeneous parity-breaking medium, such as the dense hot hadronic matter with chiral imbalance. The transition between the regions with approximately constant values of the parity-breaking parameter allows for the states localized on such boundary to occur. The adiabatic change of the background introduces either decay or the amplification of the localized states.Comment: bibliography and some textual improvement

Examining Fate: The Debate over Children’s Identity in the Border Areas of Interwar Eastern Upper Silesia

This article deals with two little-known disputes over the national identity of a population in the interwar border area of Eastern Upper Silesia. This area was transferred from Germany to Poland after World War I as a result of a plebiscite. Its local population, the Silesians, did not consider themselves entirely German or Polish, but still underwent a process of Polonization. The plebiscite took place in Upper Silesia in 1921, prompting international controversy and internal debate within the Polish state about how to define the nationality of the Silesians in the context of their internationally protected rights as a “minority.” As this article shows, the Silesians were utilized by Central and Western European politicians as objects of international diplomacy and by the Polish authorities to advance their internal policies. The story of “Maurer’s children” and Silesian children born out of wedlock illustrates the reaction of the Silesian population to the interwar politics of nationalization. These cases attracted international attention from 1926 to 1928 and brought questions of national minorities, bilingual children, and self-definition of nationality vis-à-vis the state’s requirements to the level of international debate

Creation of a homogeneous plasma column by means of hohlraum radiation for ion-stopping measurements

In this work, we present the results of two-dimensional radiation-hydrodynamics simulations of a hohlraum target whose outgoing radiation is used to produce a homogeneously ionized carbon plasma for ion-beam stopping measurements. The cylindrical hohlraum with gold walls is heated by a frequency-doubled ($\lambda_l = 526.5$ $\mu m$) $1.4$ $ns$ long laser pulse with the total energy of $E_l = 180$ $J$. At the laser spot, the peak matter and radiation temperatures of, respectively, $T \approx 380$ $eV$ and $T_r \approx 120$ $eV$ are observed. X-rays from the hohlraum heat the attached carbon foam with a mean density of $\rho_C = 2$ $mg/cm^3$ to a temperature of $T \approx 25$ $eV$. The simulation shows that the carbon ionization degree ($Z \approx 3.75$) and its column density stay relatively stable (within variations of about $\pm7\%$) long enough to conduct the ion-stopping measurements. Also, it is found that a special attention should be paid to the shock wave, emerging from the X-ray heated copper support plate, which at later times may significantly distort the carbon column density traversed by the fast ions.Comment: 12 pages, 12 figure

Vacuum Effect on the Lactide Yield

The vacuum effect on the yield and purity of lactide obtained by catalytic lactic acid oligomer depolymerization was investigated. As raw material for the lactic acid oligomer synthesis the L-lactic acid aqueous solution was used. It was shown that the highest yield of raw-lactide takes place via distillation under a vacuum. The raw-lactide in all fractions was purified by recrystallization from dry ethyl acetate. The highest yield of raw-lactide is observed at a vacuum of 10 ... 15 mbar. The distillation process of raw-lactide is complicated with chemical reactions. Control of the reaction, raw materials and products was performed using DTA, gel permeation chromatography, infrared spectroscopy and high performance liquid chromatography

The Polymer Stress Tensor in Turbulent Shear Flows

The interaction of polymers with turbulent shear flows is examined. We focus on the structure of the elastic stress tensor, which is proportional to the polymer conformation tensor. We examine this object in turbulent flows of increasing complexity. First is isotropic turbulence, then anisotropic (but homogenous) shear turbulence and finally wall bounded turbulence. The main result of this paper is that for all these flows the polymer stress tensor attains a universal structure in the limit of large Deborah number \De\gg 1. We present analytic results for the suppression of the coil-stretch transition at large Deborah numbers. Above the transition the turbulent velocity fluctuations are strongly correlated with the polymer's elongation: there appear high-quality "hydro-elastic" waves in which turbulent kinetic energy turns into polymer potential energy and vice versa. These waves determine the trace of the elastic stress tensor but practically do not modify its universal structure. We demonstrate that the influence of the polymers on the balance of energy and momentum can be accurately described by an effective polymer viscosity that is proportional to to the cross-stream component of the elastic stress tensor. This component is smaller than the stream-wise component by a factor proportional to \De ^2 . Finally we tie our results to wall bounded turbulence and clarify some puzzling facts observed in the problem of drag reduction by polymers.Comment: 11 p., 1 Fig., included, Phys. Rev. E., submitte

Risks to the Human Rights Advocacy in African Constitutions

This article presents the results of a comparative legal study of the texts of the constitutions of African states with a view to identifying the rules that minimize human rights risks. The research is based on a dialectical approach to the disclosure of legal phenomena and processes using general scientific (systematic and logical methods, analysis and synthesis) and specific scientific methods. African constitutions, in comparison with the constitutions of other states, and in particular European ones, contain a disproportionately large number of rules formalizing special human rights institutions. Typically, these are special councils, human rights commissions (Egypt, Morocco, and Tunisia) or certain categories of the population (three in Egypt, three in Morocco, one in the Central African Republic). In Morocco and Equatorial Guinea, both the Mediator and the Public Defender are established, respectively. The relevance of the study is due to the strategic objectives of creating a secure human rights status of the state, as well as the need to find and update theoretical, methodological, and practical approaches to protecting the rights and freedoms of a human and a citizen. Considering the rules of the African constitutional model of minimizing risks to human right advocacy, objectively in terms of quantity and quality, are considered hyperbolic

Groundwater level management in a reclamation system

Soil fertility largely depends on the water regime of the territories. Yields on agricultural lands that are subject to flooding and waterlogging are low. On the other hand, lowering the groundwater level also negatively affects soil fertility. The desiccation of the soil leads to the destruction and weathering of the fertile layer. The periodic repetition of the processes of waterlogging, flooding and desiccation of soils leads to soil fusion, that is, the process of degradation of the soil cover does not stop. The reduction of arable land under the influence of various negative factors (deflation, salinization, acidification, desiccation, flooding and waterlogging of lands) reduces the social and economic development of regions. Crop shortages negatively affect the stability of the economy in agriculture. One of the main negative factors of economic destabilization is the degradation of arable land in the south of Russia from flooding