Теплообмен при течении Куэтта с учетом теплоты трения

An approximate analytical solution of a non-linear problem concerning heat transfer in the liquid at Couette flow with due account of friction heat has been obtained on the basis of the Kantarovich orthogonal method. The solution has made it possible to carry out temperature investigations at small values of an axial coordinate. Being obtained in the fifth approximation the solution has permitted for the first time to value liquid temperature within the range of the axial spatial coordinate. The analysis of the obtained results has revealed that a temperature maximum shift to motionless flow has been observed at small values of the axial coordinate.It is possible to make a conclusion that in order to protect devices that are moving with high speed in various media it is necessary to organize boundary layer disruption that allows to avoid stabilization of a temperature field in a flow which promotes wall over-heating due to energy dissipation.На основе ортогонального метода Л. В. Канторовича получено приближенное аналитическое решение нелинейной задачи теплообмена в жидкости при течении Куэтта с учетом теплоты трения, позволяющее проводить исследования температуры для малых значений продольной координаты.Полученное в пятом приближении решение позволило впервые выполнить оценку температуры жидкости в диапазоне продольной пространственной координаты. Анализ полученных результатов показал, что при малых значениях продольной координаты наблюдается смещение максимума температуры в сторону неподвижного потока.можно сделать вывод о том, что для защиты устройств, движущихся с высокой скоростью в разных средах, следует так организовать срыв пограничного слоя, чтобы не происходила стабилизация температурного поля в потоке, способствующая перегреву стенки от диссипации энергии

Spin-orbit Hanle effect in high-mobility quantum wells

We study the depolarization of optically oriented electrons in quantum wells subjected to an in-plane magnetic field and show that the Hanle curve drastically depends on the carrier mobility. In low-mobility structures, the Hanle curve is described by a Lorentzian with the width determined by the effective g-factor and the spin lifetime. In contrast, the magnetic field dependence of spin polarization in high-mobility quantum wells is nonmonotonic: The spin polarization rises with the magnetic field induction at small fields, reaches maximum and then decreases. We show that the position of the Hanle curve maximum can be used to directly measure the spin-orbit Rashba/Dresselhaus magnetic field.Comment: 4 pages, 3 figure

Comment on `Dynamical properties of small polarons'

We show that the conclusion on the breakdown of the standard small polaron theory made recently by E.V. deMello and J. Ranninger (Phys. Rev. B 55, 14872 (1997)) is a result of an incorrect interpretation of the electronic and vibronic energy levels of the two-site Holstein model. The small polaron theory, when properly applied, agrees well with the numerical results of these authors. Also we show that their attempt to connect the properties of the calculated correlation functions with the features of the intersite electron hopping is unsuccessful.Comment: To appear in Phys. Rev.

Calculation of the cut-off and evaluation of the dynamics of natriuretic peptide for optimization the management of comorbid patients with thyrototoxicosis and heart failure

Objective: to determine the cut-off of natriuretic peptide for optimization dyagnosis heart failure in comorbid patients with thyrotoxicosis, to assess the dynamics of this indicator during therapy.Materials and methods: 111 patients (58,3±5,6 years) were divided into 4 groups. Te main group consisted of 25 patients with CHD, CHF II-III FC and thyrotoxicosis; the 1st group of comparison - 30 patients with CHD and CHF II-III FC, without thyrotoxicosis; the 2nd group — 30 patients with thyrotoxicosis without CHD, the 3rd group - 26 patients with thyrotoxicosis and CHD, with no signs of CHF. Te fnding of thyroid gland, the level of NT-proBNP was estimated at baseline and afer 6 months therapy. A new cut-off NT-proBNP for the diagnosis of CHF in comorbid patients was calculated by using ROC analysis.Results: the high concentration of NT-proBNP was detected in all patients (more then 125 pg/ml), in the 2nd comparison group — 225.5 (180.1, 376.1) pg/ml. Te NT-proBNP values in the patients of the 1st and 3rd comparison groups did not differ signifcantly. Te highest level of NT-proBNP was detected in the main group — 712.1 (434.3, 893.9) pg/ml. A cut-off of this marker for screening CHF in comorbid patients with CHD and thyrotoxicosis was calculated - 556.4 pg/ml (a sensitivity of 72 %, a specifcity of 100 %, an accuracy of 87.2 % (p <0.001)). Afer 6 months therapy in the 2nd comparison group the level of NT-proBNP decreased by 74 % (р<0,0001) and has reached the normal value (64,6 (42,2;76,3)); in the main group the level decreased by 43% and was 406,7 (309,1; 498,6) pg/ml.Conclusions: the patients of all groups showed an increased concentration of NT-proBNP. Te highest level of NT-proBNP was observed in the group of patients with CHF by CHD and thyrotoxicosis. Te level of NT-proBNP was determined - 556.4 pg/ml, which allows us to diagnose CHF in patients with a combination of CHD and thyrotoxicosis

Modifying the surface electronic properties of YBa2Cu3O7-delta with cryogenic scanning probe microscopy

We report the results of a cryogenic study of the modification of YBa2Cu3O7-delta surface electronic properties with the probe of a scanning tunneling microscope (STM). A negative voltage applied to the sample during STM tunneling is found to modify locally the conductance of the native degraded surface layer. When the degraded layer is removed by etching, the effect disappears. An additional surface effect is identified using Scanning Kelvin Probe Microscopy in combination with STM. We observe reversible surface charging for both etched and unetched samples, indicating the presence of a defect layer even on a surface never exposed to air.Comment: 6 pages, 4 figures. To appear in Superconductor Science and Technolog

Spectra of high n and non-low n degrees

We survey known results on spectra of structures and on spectra of relations on computable structures, asking when the set of all highn degrees can be such a spectrum, and likewise for the set of non-low n degrees. We then repeat these questions specifically for linear orders and for relations on the computable dense linear order ℚ. New results include realizations of the set of non-low n Turing degrees as the spectrum of a relation on ℚ for all n≥1, and a realization of the set of all non-low n Turing degrees as the spectrum of a linear order whenever n≥2. The state of current knowledge is summarized in a table in the concluding section. © 2010 The Author. Published by Oxford University Press. All rights reserved

Genome-wide association studies targeting the yield of extraembryonic fluid and production traits in Russian White chickens

Background: The Russian White is a gene pool breed, registered in 1953 after crossing White Leghorns with local populations and, for 50 years, selected for cold tolerance and high egg production (EL). The breed has great potential in meeting demands of local food producers, commercial farmers and biotechnology sector of specific pathogen-free (SPF) eggs, the former valuing the breed for its egg weight (EW), EL, age at first egg (AFE), body weight (BW), and the latter for its yield of extraembryonic fluid (YEF) in 12.5-day embryos, ratio of extraembryonic fluid to egg weight, and embryo mass. Moreover, its cold tolerance has been presumably associated with day-old chick down colour (DOCDC) white rather than yellow, the genetic basis of these traits being however poorly understood. Results: We undertook genome-wide association studies (GWASs) for eight performance traits using single nucleotide polymorphism (SNP) genotyping of 146 birds and an Illumina 60KBeadChip. Several suggestive associations (p <5.16*10(-5)) were found for YEF, AFE, BW and EW. Moreover, on chromosome 2, an association with the white DOCDC was found where there is an linkage disequilibrium block of SNPs including genes that are responsible not for colour, but for immune resistance. Conclusions: The obtained GWAS data can be used to explore the genetics of immunity and carry out selection for increasing YEF for SPF eggs production.Peer reviewe

Charge transfer and coherence dynamics of tunnelling system coupled to a harmonic oscillator

We study the transition probability and coherence of a two-site system, interacting with an oscillator. Both properties depend on the initial preparation. The oscillator is prepared in a thermal state and, even though it cannot be considered as an extended bath, it produces decoherence because of the large number of states involved in the dynamics. In the case in which the oscillator is intially displaced a coherent dynamics of change entangled with oscillator modes takes place. Coherency is however degraded as far as the oscillator mass increases producing a increasingly large recoherence time. Calculations are carried on by exact diagonalization and compared with two semiclassical approximations. The role of the quantum effects are highlighted in the long-time dynamics, where semiclassical approaches give rise to a dissipative behaviour. Moreover, we find that the oscillator dynamics has to be taken into account, even in a semiclassical approximation, in order to reproduce a thermally activated enhancement of the transition probability

On psychosemantics of notions "opinion", "knowledge", "belief"

© IAEME Publication. Currently the studies of particular relevance in which the ways of representation in the language of the subject's consciousness cognitive content, the characteristic properties of thinking verbal objectification and the basic thought features are analyzed. This article deals with the universal categories of knowledge, opinion and belief, largely structuring the cognitive, mental activity of a person, serving as the basic constructs in the subject's cognitive-evaluative activity. The paper presents the results of a series of our psychosemantic experiments, which made it possible to identify stable signs, cultural representations, associations that arise in the minds of native speakers in the actualization of categories of knowledge, opinion and belief and compare their content. Such experimental studies allow us to explicate the "hidden" mechanisms of verbalization of thought structures in the process of cognition of the world, to see what stands behind the word as a unit of the speech (linguistic) ability of the individual. The submitted data reflect the complex networks of relationships formed in conceptualization and categorization processes of the world

Research of the Influence of Fluctuation and Shock Oscillations on the Sensitivity of Superregenerative Transceivers

Поступила: 30.06.2019. Принята в печать: 10.07.2019.Received: 30.06.2019. Accepted: 10.07.2019.Рассматриваются вопросы ударного возбуждения колебательной системы транзисторного сверхрегенеративного приемопередающего устройства в момент запуска импульсами тока для разных законов затухания и их влияние на чувствительность и усиление в приемном режиме работы, определение условий достижения высокой чувствительности устройства к слабым внешним сигналам на основе анализа флуктуационных колебаний в приемном режиме работы, оценка полосы пропускания входного колебательного контура сверхрегенеративного приемопередатчика при нулевом значении затухания этого контура, а также оценка суммарного воздействия ударных и флуктуационных колебаний на параметры сверхрегенеративного приемопередатчика.We study the issues of shock excitation of the oscillatory system of a transistor superregenerative transceiver at the moment of starting with current pulses for different damping laws and their influence on the sensitivity and gain in the receiving mode of operation, determining the conditions for achieving high sensitivity of the device to weak external signals based on the analysis of fluctuation fluctuations in the receiving mode of operation. We evaluate the bandwidth of the input oscillatory circuit of the superregenerative transceiver at zero damping of this circuit. We estimate the total impact shock and vibrations on the fluctuation parameters superregenerative transceiver