Giant electrocaloric effect in thin film Pb Zr_0.95 Ti_0.05 O_3

An applied electric field can reversibly change the temperature of an electrocaloric material under adiabatic conditions, and the effect is strongest near phase transitions. This phenomenon has been largely ignored because only small effects (0.003 K V^-1) have been seen in bulk samples such as Pb0.99Nb0.02(Zr0.75Sn0.20Ti0.05)0.98O3 and there is no consensus on macroscopic models. Here we demonstrate a giant electrocaloric effect (0.48 K V^-1) in 300 nm sol-gel PbZr0.95Ti0.05O3 films near the ferroelectric Curie temperature of 222oC. We also discuss a solid state device concept for electrical refrigeration that has the capacity to outperform Peltier or magnetocaloric coolers. Our results resolve the controversy surrounding macroscopic models of the electrocaloric effect and may inspire ab initio calculations of electrocaloric parameters and thus a targeted search for new materials.Comment: 5 pages, 4 figure

On a class of integrable systems connected with GL(N,\RR)

In this paper we define a new class of the quantum integrable systems associated with the quantization of the cotangent bundle $T^*(GL(N))$ to the Lie algebra $\frak{gl}_N$. The construction is based on the Gelfand-Zetlin maximal commuting subalgebra in $U(\frak{gl}_N)$. We discuss the connection with the other known integrable systems based on $T^*GL(N)$. The construction of the spectral tower associated with the proposed integrable theory is given. This spectral tower appears as a generalization of the standard spectral curve for integrable system.Comment: LaTeX, 13 page

Giant Keplerate molecule Fe30 - the first octopole magnet

The multipole expansion technique is applied to one of the largest magnetic molecules, Fe30. The molecule's dipole, toroid and quadrupole magnetic moments are equal to zero (in the absence of magnetic field) so the multipole expansion starts from the octopole moment. Probably the Fe30 molecule is the most symmetrical magnetic body synthesized so far. The magnetization process is considered theoretically in different geometries. Some components of the octopole moment experience a jump while the magnetization rises linearly up to its saturation value. An elementary octopole moment consisting of four magnetic dipoles is proposed as a hint for designing of an experiment for measurement of octopole magnetic moment components.Comment: 7 pages, 9 figure

Does the Madden-Julian Oscillation influence aerosol variability?

We investigate the modulation of aerosols by the Madden-Julian Oscillation (MJO) using multiple, global satellite aerosol products: aerosol index (AI) from the Total Ozone Mapping Spectrometer (TOMS) on Nimbus-7, and aerosol optical thickness (AOT) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Advanced Very High Resolution Radiometer (AVHRR) on NOAA satellites. A composite MJO analysis indicates that large variations in the TOMS AI and MODIS/AVHRR AOT are found over the equatorial Indian and western Pacific Oceans where MJO convection is active, as well as the tropical Africa and Atlantic Ocean where MJO convection is weak but the background aerosol level is high. A strong inverse linear relationship between the TOMS AI and rainfall anomalies, but a weaker, less coherent positive correlation between the MODIS/AVHRR AOT and rainfall anomalies, were found. The MODIS/AVHRR pattern is consistent with ground-based Aerosol Robotic Network data. These results indicate that the MJO and its associated cloudiness, rainfall, and circulation variability systematically influence the variability in remote sensing aerosol retrieval results. Several physical and retrieval algorithmic factors that may contribute to the observed aerosol-rainfall relationships are discussed. Preliminary analysis indicates that cloud contamination in the aerosol retrievals is likely to be a major contributor to the observed relationships, although we cannot exclude possible contributions from other physical mechanisms. Future research is needed to fully understand these complex aerosol-rainfall relationships

Influence of low-frequency vibration on the erythrocytes acid resistance

Досліджено дію низькочастотної вібрації (діапазон частот 8–32 Гц, амплітуди 0,5 ± 0,04 та 0,9 ± 0,08 мм) на кислотну резистентність еритроцитів. Охарактеризовано кінетику окремих стадій гемолізу. Оцінено частотно-часові залежності констант швидкості стадій гемолізу. Вібрація з частотами 8–16 Гц, амплітудою 0,5 ± 0,04 та 8 Гц, амплітудою 0,9 ± 0,08 мм викликає деструктивні перебудови водно-білкового складу цитоплазми, що викликає зниження бар’єру проникності для гемолітичного агента. При вібраційному впливі інтервалу частот 20–32 Гц, в результаті окислювального стресу, переважають реакції модифікувального характеру, що викликають агрегацію клітинних білків, зокрема білка смуги 3.Исследовано действие низкочастотной вибрации (диапазон частот 8–32 Гц, амплитуды 0,5 ± 0,04 и 0,9 ± 0,08 мм) на кислотную резистентность эритроцитов. Охарактеризована кинетика отдельных стадий гемолиза. Оценены частотно-временные зависимости констант скоростей стадий гемолиза. Вибрация с частотами 8–16 Гц, амплитудой 0,5 ± 0,04 мм и 8 Гц, амплитудой 0,9 ± 0,08 мм вызывает деструктивные перестройки водно-белкового состава цитоплазмы, приводящие к снижению барьера проницаемости для гемолитического агента. При вибрационном воздействии интервала частот 20–32 Гц, в результате окислительного стресса, преобладают реакции модифицирующего характера, приводящие к агрегации клеточных белков и, в частности, белка полосы 3.The influence of low-frequency vibration (frequency range 8–32 Hz, amplitudes 0.5 ± 0.04 and 0.9 ± 0.08 mm) on the erythrocytes’ acid resistance was studied. The kinetics of various hemolysis stages was investigated. The time-frequency dependences of the kinetics constants of hemolysis stages were obtained and discussed. It was shown that 8–16 Hz vibration with the 0.5 mm amplitude and 8 Hz with 0.9 mm causes destructive reorganizations of a cytoplasm’s water-protein structure. It leads to decrease in a permeability barrier for a hemolytic agent. As a result of oxidizing stress the vibration in the frequency range of 20–32 Hz causes the modifying reactions leading to the aggregation of cellular proteins and, in particular, the band 3 protein

Small business development and resource use in Russian regions

Relevance. The living standards in any country largely depend on how developed is this country’s business sector. The latter, in its turn, relies on the availability and efficient use of resources. The problem that arises in this respect and that this study seeks to address is how to measure the resource potential available for the development of small businesses in order to choose the optimal strategy of stimulating this sector for this or that region.Research objective. The aim of this research is to study resources available to small businesses and their use in Russian regions.Data and methods. The set of indicators used in our analysis helps us measure the activity of small businesses in Russian federal districts. The key elements of the assessment are based on the official statistics and include the following: average labor productivity of small businesses, the unit turnover per small enterprise, the number of small firms per 10,000 people. Each of these indicators was analyzed by using the methods of mathematical statistics according to the three criteria: stability (S); average values (M); and the variability of the results (V), which characterizes interregional differentiation within a federal district/country.Results. The article proposes a system of indicators for diagnosing small business development based on the concentration and performance of small-sized enterprises. The quantitative results of such analysis can be used for choosing strategies of small business development.Conclusion. There was a significant decline in entrepreneurial activity during the post-crisis period of 2017-2018 in Russia, which could be explained by the impact of foreign sanctions and the difficult economic situation in the country (inflation, a sharp rise in the price of resources, difficulties in communication with international partners, and the difficulty or even impossibility to adopt efficient technologies in a short time). As our analysis has shown, some of the Russian territories still have underutilized resource potential that can be used for stimulating small business development