Properties of 1D two-barrier quantum pump with harmonically oscillating barriers

We study a one-dimensional quantum pump composed of two oscillating delta-functional barriers. The linear and non-linear regimes are considered. The harmonic signal applied to any or both barriers causes the stationary current. The direction and value of the current depend on the frequency, distance between barriers, value of stationary and oscillating parts of barrier potential and the phase shift between alternating voltages.Comment: 7 pages, 8 figure

Theory of one-dimensional double-barrier quantum pump in two-frequency signal regime

A one-dimensional system with two $\delta$-like barriers or wells bi-chromaticaly oscillating at frequencies $\omega$ and $2\omega$ is considered. The alternating signal leads to the direct current across the structure (even in a symmetric system). The properties of this quantum pump are studied in a wide range of the system parameters.Comment: 4 pages, 5 figure

Thermal radiation of conducting nanoparticles

The thermal radiation of small conducting particles was investigated in the region where the Stephan-Boltzmann law is not valid and strongly overestimates radiation losses. The new criterion for the particle size, at which black body radiation law fails, was formulated. The approach is based on the magnetic particle polarization, which is valid until very small sizes (cluster size) where due to drop of particle conductivity the electric polarization prevails over the magnetic one. It was also shown that the radiation power of clusters, estimated on the basis of the experimental data, is lower than that given by the Stephan-Boltzmann law.Comment: 12 pages, 5 figures, 1 tabl

Complex bounds for multimodal maps: bounded combinatorics

We proved the so called complex bounds for multimodal, infinitely renormalizable analytic maps with bounded combinatorics: deep renormalizations have polynomial-like extensions with definite modulus. The complex bounds is the first step to extend the renormalization theory of unimodal maps to multimodal maps.Comment: 20 pages, 3 figure

Rotation sets of billiards with one obstacle

We investigate the rotation sets of billiards on the $m$-dimensional torus with one small convex obstacle and in the square with one small convex obstacle. In the first case the displacement function, whose averages we consider, measures the change of the position of a point in the universal covering of the torus (that is, in the Euclidean space), in the second case it measures the rotation around the obstacle. A substantial part of the rotation set has usual strong properties of rotation sets

The oxycoal process with cryogenic oxygen supply

Due to its large reserves, coal is expected to continue to play an important role in the future. However, specific and absolute CO2 emissions are among the highest when burning coal for power generation. Therefore, the capture of CO2 from power plants may contribute significantly in reducing global CO2 emissions. This review deals with the oxyfuel process, where pure oxygen is used for burning coal, resulting in a flue gas with high CO2 concentrations. After further conditioning, the highly concentrated CO2 is compressed and transported in the liquid state to, for example, geological storages. The enormous oxygen demand is generated in an air-separation unit by a cryogenic process, which is the only available state-of-the-art technology. The generation of oxygen and the purification and liquefaction of the CO2-enriched flue gas consumes significant auxiliary power. Therefore, the overall net efficiency is expected to be lowered by 8 to 12 percentage points, corresponding to a 21 to 36% increase in fuel consumption. Oxygen combustion is associated with higher temperatures compared with conventional air combustion. Both the fuel properties as well as limitations of steam and metal temperatures of the various heat exchanger sections of the steam generator require a moderation of the temperatures during combustion and in the subsequent heat-transfer sections. This is done by means of flue gas recirculation. The interdependencies among fuel properties, the amount and the temperature of the recycled flue gas, and the resulting oxygen concentration in the combustion atmosphere are investigated. Expected effects of the modified flue gas composition in comparison with the air-fired case are studied theoretically and experimentally. The different atmosphere resulting from oxygen-fired combustion gives rise to various questions related to firing, in particular, with regard to the combustion mechanism, pollutant reduction, the risk of corrosion, and the properties of the fly ash or the deposits that form. In particular, detailed nitrogen and sulphur chemistry was investigated by combustion tests in a laboratory-scale facility. Oxidant staging, in order to reduce NO formation, turned out to work with similar effectiveness as for conventional air combustion. With regard to sulphur, a considerable increase in the SO2 concentration was found, as expected. However, the H2S concentration in the combustion atmosphere increased as well. Further results were achieved with a pilot-scale test facility, where acid dew points were measured and deposition probes were exposed to the combustion environment. Besides CO2 and water vapour, the flue gas contains impurities like sulphur species, nitrogen oxides, argon, nitrogen, and oxygen. The CO2 liquefaction is strongly affected by these impurities in terms of the auxiliary power requirement and the CO2 capture rate. Furthermore, the impurity of the liquefied CO2 is affected as well. Since the requirements on the liquid CO2 with regard to geological storage or enhanced oil recovery are currently undefined, the effects of possible flue gas treatment and the design of the liquefaction plant are studied over a wide range

Intensity and Trends in Development of Epidemic Process of Ixodes Tick-Borne Borrelioses in the Russian Federation in 2002–2018 and Forecast for 2019

Objective: to analyze the intensity and dynamics of Ixodidae tick-borne borreliosis (ITBB) incidence in Federal Districts and constituent entities of the Russian Federation (RF) in 2002–2018 and give a forecast of epidemic process development for 2019. The maximum number of cases of ITBB in 2002–2018 was registered in the Central Federal District (CFD); further on in a decreasing order, the Volga (VFD), Siberian (SiFD), North-West (NWFD), Ural (UFD), Far Eastern (FEFD), Southern (SoFD), and North Caucasian (NCFD) Federal Districts. The territories are distributed according to the incidence of ITBB, as follows (descending): NWFD, UFD, SiFD, VFD, CFD, FEFD, SoFD, NCFD. When assessing the dynamics of ITBB incidence, a reliable tendency towards decrease in the intensity of the epidemic process was found for the North-West Federal District and the Volga Federal District, in contrast to the Central Federal District, the Southern Federal District and the North-West Federal District, where there is a significant upward trend. For the UFD, the Siberian Federal District, Far Eastern Federal District, and the Russian Federation on the whole the variation in the incidence rates within the confidence intervals of the long-term annual average values is the most likely to be observed in the near future. The constituent entities of the Russian Federation were ranked according to the levels of ITBB morbidity; the trends in epidemic process development, depending upon the degree of epidemic hazard of the territory, were determined. In half of the 26 entities of the Russian Federation, with the average annual incidence rate above 6.5 о /оооо, a reliable trend in epidemic process intensity reduction was revealed. The exception is the Kemerovo Region and the Republic of Tuva, where further increase in ITBB incidence is probable. In the group of 15 entities of the Russian Federation with the average annual incidence of ITBB ranging from 2.9 о /оооо to 6.5 о /оооо, both the tendency towards growth and decrease or absence of a reliable trend in the intensity of the epidemic process is observed with approximately equal frequency. In the group of entities with the average annual incidence rates of ITBB less than 2.9 о /оооо, the increment of the indicator values in the future is highly probable

Energy Spectra, Altitude Profiles and Charge Ratios of Atmospheric Muons

We present a new measurement of air shower muons made during atmospheric ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio mu+ / mu- is presented as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c. The differential mu- momentum spectra are presented between 0.3 and about 50 GeV/c at atmospheric depths between 13 and 960 g/cm^2. We compare our measurements with other recent data and with Monte Carlo calculations of the same type as those used in predicting atmospheric neutrino fluxes. We find that our measured mu- fluxes are smaller than the predictions by as much as 70% at shallow atmospheric depths, by about 20% at the depth of shower maximum, and are in good agreement with the predictions at greater depths. We explore the consequences of this on the question of atmospheric neutrino production.Comment: 11 pages, 8 figures, to appear in Phys. Rev. D (2000