Chaos and rectification of electromagnetic wave in a lateral semiconductor superlattice

We find the conditions for a rectification of electromagnetic wave in a lateral semiconductor superlattice with a high mobility of electrons. The rectification is assisted by a transition to a dissipative chaos at a very high mobility. We show that mechanism responsible for the rectification is a creation of warm electrons in the superlattice miniband caused by an interplay of the effects of nonlinearity and finite band width.Comment: 4 pages, 4 figures (2 color figs). Sufficient revision in comparison with version1: More explanations on physics of the effect are added. Removed from version1 material will be published elsewher

Probes of Lorentz Violation in Neutrino Propagation

It has been suggested that the interactions of energetic particles with the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects might violate Lorentz invariance, so that they do not propagate at a universal speed of light. We consider the limits that may be set on a linear or quadratic violation of Lorentz invariance in the propagation of energetic neutrinos, v/c=[1 +- (E/M_\nuQG1)] or [1 +- (E/M_\nu QG2}^2], using data from supernova explosions and the OPERA long-baseline neutrino experiment. Using the SN1987a neutrino data from the Kamioka II, IMB and Baksan experiments, we set the limits M_\nuQG1 > 2.7(2.5)x10^10 GeV for subluminal (superluminal) propagation, respectively, and M_\nuQG2 >4.6(4.1)x10^4 GeV at the 95% confidence level. A future galactic supernova at a distance of 10 kpc would have sensitivity to M_\nuQG1 > 2(4)x10^11 GeV for subluminal (superluminal) propagation, respectively, and M_\nuQG2 > 2(4)x10^5 GeV. With the current CNGS extraction spill length of 10.5 micro seconds and with standard clock synchronization techniques, the sensitivity of the OPERA experiment would reach M_\nuQG1 ~ 7x10^5 GeV (M_\nuQG2 ~ 8x10^3 GeV) after 5 years of nominal running. If the time structure of the SPS RF bunches within the extracted CNGS spills could be exploited, these figures would be significantly improved to M_\nuQG1 ~ 5x10^7 GeV (M_\nuQG2 ~ 4x10^4 GeV). These results can be improved further if similar time resolution can be achieved with neutrino events occurring in the rock upstream of the OPERA detector: we find potential sensitivities to M_\nuQG1 ~ 4x10^8 GeV and M_\nuQG2 ~ 7x10^5 GeV.Comment: 33 pages, 22 figures, version accepted for publication in Physical Review

A comparative study of hydrophilic phosphine hexanuclear rhenium cluster complexes’ toxicity

Octahedral rhenium cluster compound Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] has recently emerged as a very promising X-ray contrast agent for biomedical applications. However, the synthesis of this compound is rather challenging due to difficulty to control the hydrolysis of initial P(C2H4CN)3 ligand during the reaction process. Therefore, in this report we compare the in vitro and in vivo toxicity of Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] with those of related compounds featuring fully hydrolysed form of the phosphine ligand, namely Na2H14[{Re6Q8}(P(C2H4COO)3)6] (Q = S or Se). Our results demonstrate that cytotoxicity and acute in vivo toxicity of the complex Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] solutions were considerably lower than those of compounds with fully hydrolysed ligand P(C2H4COOH)3. Such behavior can be explained by the higher osmolality of Na2H14[{Re6Q8}(P(C2H4COO)3)6] versus Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6]

Exploration of Possible Quantum Gravity Effects with Neutrinos II: Lorentz Violation in Neutrino Propagation

It has been suggested that the interactions of energetic particles with the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects might violate Lorentz invariance, so that they do not propagate at a universal speed of light. We consider the limits that may be set on a linear or quadratic violation of Lorentz invariance in the propagation of energetic neutrinos, v/c=[1 +- (E/M_\nuQG1)] or [1 +- (E/M_\nu QG2}^2], using data from supernova explosions and the OPERA long-baseline neutrino experiment.Comment: 8 pages, 6 figures, proceedings for invited talk by A.Sakharov at DISCRETE'08, Valencia, Spain; December 200

On Gammelgaard's formula for a star product with separation of variables

We show that Gammelgaard's formula expressing a star product with separation of variables on a pseudo-Kaehler manifold in terms of directed graphs without cycles is equivalent to an inversion formula for an operator on a formal Fock space. We prove this inversion formula directly and thus offer an alternative approach to Gammelgaard's formula which gives more insight into the question why the directed graphs in his formula have no cycles.Comment: 29 pages, changes made in the last two section

Digitalization of the Russian Energy Sector: State-of-the-art and Potential for Future Research

In this paper, we review forty seven best papers on digitalization of the Russian fuel and energy complex. All the papers are written in Russian and published in a number of Russian academic journals that are mostly distributed via closed national library systems and, consequently, are not available for foreign scholars interested in studying Russia's energy policies. Our review identifies a total of five research directions in the Russian scholarship: (i) general trends in digitalization of the Russian fuel and energy complex; (ii) concepts and approaches used by the Russian scholars; (iii) government policies; (iv) digital technologies; and (v) security concerns. Each research direction is carefully covered and analyzed. Then, we identify gaps in the Russian scholarship and propose three potential research areas. Keywords: Digitalization, Energy Industries, Russia, Contemporary Scholarship JEL Classifications: Q2, Q3, Q4 DOI: https://doi.org/10.32479/ijeep.7673

A quantitative Analysis of Energy Security Performance by Brazil, Russia, India, China, and South Africa in 1990-2015

The paper addresses the gap existing in the scholarship and provides an analysis of the energy security performance made by the group of BRICS (Brazil, Russia, India, and South Africa) over the total of 25 years, from 1990 to 2015. The research is based on a comprehensive approach to understanding energy security as the total of four dimensions: availability, efficiency, affordability, and environmental stewardship. An energy security performance index operationalizes each dimension of energy security with three indicators, which allows to quantitatively measure the progress made by the group of BRICS in terms of ensuring their energy security. The research conducted surprisingly shows that the overall energy security of BRICS as a group of states has not changed over the years. However, each country has experienced considerable changes in energy security performance, with the most dramatic ones made by Russia (growth) and China (decline). Keywords: Energy Security, Index, BRICS JEL Classifications: Q2, Q3, Q4 DOI: https://doi.org/10.32479/ijeep.758

A Critical Review of Russia's Energy Efficiency Policies in the Construction and Housing Sector

The paper critically reviews the existing energy efficiency policies in the construction and housing sector of Russia, focusing on the following: (i) the government management system; (ii) technological regulations; (iii) financial incentives and funding; (iv) and supporting mechanisms. The methodology used by the Government of Russia to specifically monitor energy efficiency performance in the construction and housing sector is evaluated, with the use of statistical data obtained from the government statistical service. On the basis of the conducted review, the paper proposes three recommendations for the Government of Russia, which could become the first step for improving energy efficiency policies in the construction and housing sector: (i) to provide an appropriate assessment of the energy efficiency potential; (ii) to develop a comprehensive regulatory framework and implementation mechanisms aimed at increasing energy efficiency; (iii) to develop a clear causal mechanism between energy efficiency policies and actual performance, which could be quantitatively measured using an appropriate methodology. Keywords: Energy Efficiency, Construction and Housing, Russia JEL Classifications: Q43, Q48, L74, L78, N64 DOI: https://doi.org/10.32479/ijeep.760

Effect of temperature on resonant electron transport through stochastic conduction channels in superlattices

We show that resonant electron transport in semiconductor superlattices with an applied electric and tilted magnetic field can, surprisingly, become more pronounced as the lattice and conduction electron temperature increases from 4.2 K to room temperature and beyond. It has previously been demonstrated that at certain critical field parameters, the semiclassical trajectories of electrons in the lowest miniband of the superlattice change abruptly from fully localized to completely unbounded. The unbounded electron orbits propagate through intricate web patterns, known as stochastic webs, in phase space, which act as conduction channels for the electrons and produce a series of resonant peaks in the electron drift velocity versus electric-field curves. Here, we show that increasing the lattice temperature strengthens these resonant peaks due to a subtle interplay between the thermal population of the conduction channels and transport along them. This enhances both the electron drift velocity and the influence of the stochastic webs on the current-voltage characteristics, which we calculate by making self-consistent solutions of the coupled electron transport and Poisson equations throughout the superlattice. These solutions reveal that increasing the temperature also transforms the collective electron dynamics by changing both the threshold voltage required for the onset of self-sustained current oscillations, produced by propagating charge domains, and the oscillation frequency

Probing Lorentz Violation in Neutrino Propagation from a Core-Collapse Supernova

Supernova explosions provide the most sensitive probes of neutrino propagation, such as the possibility that neutrino velocities might be affected by the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects. Recent two-dimensional simulations of the neutrino emissions from core-collapse supernovae suggest that they might exhibit variations in time on the scale of a few milliseconds. We analyze simulations of such neutrino emissions using a wavelet technique, and consider the limits that might be set on a linear or quadratic violation of Lorentz invariance in the group velocities of neutrinos of different energies, v/c = [1 \pm (E/M_{nuLV1})] or [1 \pm (E/M_{\nuLV2})^2], if variations on such short time scales were to be observed, where the mass scales M_{nuLVi} might appear in models of quantum gravity. We find prospective sensitivities to M_{nuLV1} ~ 2 X 10^{13} GeV and M_{nuLV2} ~ 10^6 GeV at the 95% confidence level, up to two orders of magnitude beyond estimates made using previous one-dimensional simulations of core-collapse supernovae. We also analyze the prospective sensitivities to scenarios in which the propagation times of neutrinos of fixed energies are subject to stochastic fluctuations.Comment: 29 pages, 9 figures. A subsection added. The version to appear in Phys. Rev.