Deformation of an Elastic Spherical Shell under the Pressure of Viscous Incompressible Fluid

The deformation of an elastic spherical shell under the pressure of viscous incompressible fluid is considered. Analytical formulas for calculating the components of normal and tangential deflections of the shell middle surface are obtained. A new mathematical model of an elastic spherical shell is offered on the basis of introduction of the Finite Element Method calculations. The comparison of the asymptotic and numerical results is performed

Binding energy constraint on matter radius and soft dipole excitations of C-22

An unusually large value of the C-22 matter radius has recently been extracted from measured reaction cross sections. The giant size can be explained by a very loose binding that is, however, not known experimentally yet. Within the three-body cluster model we have explored the sensitivity of the s-motion-dominated C-22 geometry to the two-neutron separation energy. A low energy of a few tens of keV is required to reach the alleged experimental lower value of the matter radius, while the experimental mean radius requires an extremely tiny binding. The dependence of the C-22 charge radius on the two-neutron separation energy is also presented. The soft dipole mode in C-22 is shown to be strongly affected by the loose binding and should be studied in the process of Coulomb fragmentation

Modified variable phase method for the solution of coupled radial Schrodinger equations

A modified variable phase method for the numerical solution of coupled radial Schrodinger equations, which maintains linear independence for different sets of solution vectors, is suggested. The modification involves rearrangement of coupled equations to avoid the usual numerical instabilities associated with components of the wave function in their classically forbidden regions. The modified method is applied to nuclear structure calculations of halo nuclei within the hyperspherical harmonics approach

Detection of Giant Radio Pulses from the Pulsar PSR B0656+14

Giant pulses (GPs) have been detected from the pulsar PSR B0656+14. A pulse that is more intense than the average pulse by a factor of 120 is encountered approximately once in 3000 observed periods of the pulsar. The peak flux density of the strongest pulse, 120 Jy, is a factor of 630 higher than that of the average pulse. The GP energy exceeds the energy of the average pulse by up to a factor of 110, which is comparable to that for other known pulsars with GPs, including the Crab pulsar and the millisecond pulsar PSR B1937+21. The giant pulses are a factor of 6 narrower than the average pulse and are clustered at the head of the average pulse. PSR B0656+14 along with PSR B0031-07, PSR B1112+50, and PSR J1752+2359 belong to a group of pulsars that differ from previously known ones in which GPs have been detected without any extremely strong magnetic field on the light cylinder.Comment: 10 pages, 3 figures, 1 table; originally published in Russian in Pis'ma Astron. Zh., 2006, v.32, 650; translated by George Rudnitskii; the English version will be appear in Astronomy Letter

Theory of transient spectroscopy of multiple quantum well structures

A theory of the transient spectroscopy of quantum well (QW) structures under a large applied bias is presented. An analytical model of the initial part of the transient current is proposed. The time constant of the transient current depends not only on the emission rate from the QWs, as is usually assumed, but also on the subsequent carrier transport across QWs. Numerical simulation was used to confirm the validity of the proposed model, and to study the transient current on a larger time scale. It is shown that the transient current is influenced by the nonuniform distribution of the electric field and related effects, which results in a step-like behavior of the current. A procedure of extraction of the QW emission time from the transient spectroscopy experiments is suggested.Comment: 5 pages, 4 figures, to be published in J. Appl. Phy

Noiseless Collective Motion out of Noisy Chaos

We consider the effect of microscopic external noise on the collective motion of a globally coupled map in fully desynchronized states. Without the external noise a macroscopic variable shows high-dimensional chaos distinguishable from random motion. With the increase of external noise intensity, the collective motion is successively simplified. The number of effective degrees of freedom in the collective motion is found to decrease as $-\log{\sigma^2}$ with the external noise variance $\sigma^2$. It is shown how the microscopic noise can suppress the number of degrees of freedom at a macroscopic level.Comment: 9 pages RevTex file and 4 postscript figure

Analysis of the placental tissue transcriptome of normal and preeclampsia complicated pregnancies

Preeclampsia is one of the most severe gestational complications which is one of the leading causes of maternal and perinatal morbidity and mortality. A growth in the incidence of severe and combined forms of the pathology has been observed in recent years. According to modern concepts, inadequate cytotrophoblast invasion into the spiral arteries of the uterus and development of the ischemia-reperfusion syndrome in the placental tissue play the leading role in the development of preeclampsia, which is characterized by multipleorgan failure. In this regard, our work was aimed at studying the patterns of placental tissue transcriptome that are specific to females with PE and with physiological pregnancy, as well as identifying the potential promising biomarkers and molecular mechanisms of this pathology. We have identified 63 genes whose expression proved to differ significantly in the placental tissue of females with PE and with physiological pregnancy. A cluster of differentially expressed genes (DEG) whose expression level is increased in patients with preeclampsia includes not only the known candidate genes that have been identified in many other genome-wide studies (e.g., LEP, BHLHB2, SIGLEC6, RDH13, BCL6), but also new genes (ANKRD37, SYDE1, CYBA, ITGB2, etc.), which can be considered as new biological markers of preeclampsia and are of further interest. The results of a functional annotation of DEG show that the development of preeclampsia may be related to a stress response, immune processes, the regulation of cell-cell interactions, intracellular signaling cascades, etc. In addition, the features of the differential gene expression depending on preeclampsia severity were revealed. We have found evidence of the important role of the molecular mechanisms responsible for the failure of immunological tolerance and initiation of the pro-inflammatory cascade in the development of severe preeclampsia. The results obtained elaborate the concept of the pathophysiology of preeclampsia and contain the information necessary to work out measures for targeted therapy of this disease.

CONTROL SYSTEM DEPENDING ON A PARAMETER

A nonlinear control system depending on a parameter is considered in a finite-dimensional Euclidean space and on a finite time interval. The dependence on the parameter of the reachable sets and integral funnels of the corresponding differential inclusion system is studied. Under certain conditions on the control system, the degree of this dependence on the parameter is estimated. Problems of targeting integral funnels to a target set in the presence of an obstacle in strict and soft settings are considered. An algorithm for the numerical solution of this problem in the soft setting has been developed. An estimate of the error of the developed algorithm is obtained. An example of solving a specific problem for a control system in a two-dimensional phase space is given

QUANTITATIVE ESTIMATES OF DIRECT PYROGENIC CARBON EMISSIONS IN FORESTS OF RUSSIA ACCORDING TO REMOTE MONITORING DATA 2021

This paper presents the statistics of direct wildfire carbon emission estimates during the wildfires of 2021 on forest lands of Russia using long-term satellite data. In 2021, the area affected by forest wildfires was 9.3 million ha, while carbon emissions amounted to 66.4 MtC. Said values are almost two points higher than the long-term average values. A comparison of similar indicators for twenty years allowed us to conclude that said year was anomalous with respect to the entire time series, similar to the wildfire seasons of 2003 and 2012. A period or interval for recurrence of three anomalous wildfire seasons is nine years. The reason for the recurrence of anomalous wildfire seasons is yet to be found. At the same time, the forest areas affected by wildfires, and direct carbon and other greenhouse gas emissions in anomalous wildfire years decreased from 127.2 MtC (3.7 times) in 2003 to 83.8 MtC (2.4 times) in 2012, and to 66.4 MtC (1.9 times) in 2021

On one addition to evaluation by L.S. Pontryagin of the geometric difference of sets in a plane

In this paper, two generalizations of convex sets on the plane are considered. The first generalization is the concept of the α-sets. These sets allow for the existence of several projections onto them from an arbitrary point on the plane. However, these projections should be visible from this point at an angle not exceeding α. The second generalization is related to the definition of a convex set according to which the segment connecting the two points of the convex set is also inside it. We consider central symmetric sets for which this statement holds only for two points lying on the opposite sides of some given line. For these two types of nonconvex sets, the problem of finding the maximum area subset is considered. The solution to this problem can be useful for finding suboptimal solutions to optimization problems and, in particular, linear programming. A generalization of the Pontryagin estimate for the geometric difference of an α-set and a ball is proved. In addition, as a corollary, the statement that the α-set in the plane necessarily contains a nonzero point with integer coordinates if its area exceeds a certain critical value is given. This corollary is one of generalizations of the Minkowski theorem for nonconvex sets. © 2019 Udmurt State University. All rights reserved.Russian Foundation for Basic Research, RFBR: 18–01– 00264, 18–31–00018Government Council on Grants, Russian FederationFunding. The study of the first and the third authors was funded by RFBR, project number 18–01– 00264. The study of the second author was funded by RFBR, project number 18–31–00018. The work was funded by Act 211 of the Government of the Russian Federation, contract number 02.A03.21.0006