Nelinearna analiza klizišnih procesa pod djelovanjem seizmičkih učinka

This paper investigates the stress-strain state of the slope caused by seismic activity, and taking into account the geometrical and physical nonlinearity.U članku se razmatra stanje naprezanja-deformacija padine prouzročenih seizmičkom aktivnošću uzimajući u obzir geometrijsku i fizičku nelinearnost promatrane sredine

Nelinearna analiza klizišnih procesa pod djelovanjem seizmičkih učinka

This paper investigates the stress-strain state of the slope caused by seismic activity, and taking into account the geometrical and physical nonlinearity.U članku se razmatra stanje naprezanja-deformacija padine prouzročenih seizmičkom aktivnošću uzimajući u obzir geometrijsku i fizičku nelinearnost promatrane sredine

The effect of succinic acid on the productivity of Lactuca sativa L. in artificial agroecosystems

Received: March 7th, 2021 ; Accepted: May 10th, 2021 ; Published: May 19th, 2021 ; Correspondence: [email protected] research of the effect of the biostimulant on the growth and development of plants of the ‘Robin’ lettuce variety was carried out in 2019–2020 in the department of closed artificial agroecosystems for crop production on the basis of the Federal State Budgetary Scientific Institution «Federal Scientific Agroengineering Center VIM», Moscow (VIM, Russia). Succinic acid was used at the stage of inoculation of seed and with constant drip irrigation of plants throughout the growing period. Lettuce plants were grown using a low-volume technology in a climatic chamber produced by VIM (Russia). According to the studies carried out, inoculation of seeds stimulates the development of plants at the initial stages, reducing the period from sowing to germination and increasing the rate of plant growth. As the lettuce plants grew, the leaf surface area increased from 221.0 to 1511.9 cm² with the addition of succinic acid to the hydroponic nutrient solution. The use of succinic acid under controlled growing conditions of ‘Robin’ lettuce plants allowed to increase the performance of the leaf apparatus in relation to the control. It was experimentally established that productivity directly depended on the value of photosynthetic potential and net productivity of photosynthesis, which is confirmed by a strong degree of dependence with a correlation coefficient of 0.98 and 0.77, respectively. Seed treatment and adding succinic acid to the hydroponic solution increases the accumulation of dry matter in lettuce plants. With this method of using succinic acid, significant differences in the accumulation of dry mass of plants were established. The share of the effect of the factor of inoculation of seeds with succinic acid was 17.5%, the addition of hydroponics to the nutrient solution was 50.1%. The use of succinic acid increases the accumulation of plant biomass, increases the total leaf surface area, and also contributes to an increase in the parameters of photosynthetic activity of the leaf apparatus of the ‘Robin’ lettuce plants under controlled conditions of the climatic chamber

Анализ кариотипов домашней собаки (Canis familiaris L.)

Karyotypes of sheltie and poodle breeds population of the city of Moscow are given. Describes the data on chromosomal abnormalities that occur in dogs. There are cases of chimerism and mosaicism for sex chromosomes. It is shown that in the case of chimerism on the sex chromosomes of male, repro-ductive function was normal.Описаны кариотипы собак пород шелти и пудель из популяции города Москвы. Приведены данные о хромосомных аномалиях, встречающихся у собак. Описаны случаи химеризма и мозаицизма по половым хромосомам. Показано, что в случае химеризма по половым хромосомам воспроизводительная функция у кобеля была в норме

Ball on a beam: stabilization under saturated input control with large basin of attraction

This article is devoted to the stabilization of two underactuated planar systems, the well-known straight beam-and-ball system and an original circular beam-and-ball system. The feedback control for each system is designed, using the Jordan form of its model, linearized near the unstable equilibrium. The limits on the voltage, fed to the motor, are taken into account explicitly. The straight beam-and-ball system has one unstable mode in the motion near the equilibrium point. The proposed control law ensures that the basin of attraction coincides with the controllability domain. The circular beam-and-ball system has two unstable modes near the equilibrium point. Therefore, this device, never considered in the past, is much more difficult to control than the straight beam-and-ball system. The main contribution is to propose a simple new control law, which ensures by adjusting its gain parameters that the basin of attraction arbitrarily can approach the controllability domain for the linear case. For both nonlinear systems, simulation results are presented to illustrate the efficiency of the designed nonlinear control laws and to determine the basin of attraction

Development of a Momentum Determined Electron Beam in the 1 -45 GeV Range

A beam line for electrons with energies in the range of 1 to 45 GeV, low contamination of hadrons and muons and high intensity up to 10^6 per accelerator spill at 27 GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160 micron resolution was able to measure relative electron beam momentum precisely. The resolution sigma_p p was 0.13% at 45 GeV where multiple scattering is negligible. This test beam setup provided the possibility to study properties of lead tungstate crystals (PbWO_4) for the BTeV experiment at Fermilab.Comment: 12 pages, 8 figures; work done by the BTeV Electromagnetic Calorimeter grou

Instabilities in the Flux Line Lattice of Anisotropic Superconductors

The stability of the flux line lattice has been investigated within anisotropic London theory. This is the first full-scale investigation of instabilities in the `chain' state. It has been found that the lattice is stable at large fields, but that instabilities occur as the field is reduced. The field at which these instabilities first arise, $b^*(\epsilon,\theta)$, depends on the anisotropy $\epsilon$ and the angle $\theta$ at which the lattice is tilted away from the $c$-axis. These instabilities initially occur at wavevector $k^*(\epsilon,\theta)$, and the component of $k^*$ along the average direction of the flux lines, $k_z$, is always finite. As the instability occurs at finite $k_z$ the dependence of the cutoff on $k_z$ is important, and we have used a cutoff suggested by Sudb\ospace and Brandt. The instabilities only occur for values of the anisotropy $\epsilon$ appropriate to a material like BSCCO, and not for anisotropies more appropriate to YBCO. The lower critical field $H_{c_1}(\phi)$ is calculated as a function of the angle $\phi$ at which the applied field is tilted away from the crystal axis. The presence of kinks in $H_{c_1}(\phi)$ is seen to be related to instabilities in the equilibrium flux line structure.Comment: Extensively revised paper, with modified analysis of elastic instabilities. Calculation of the lower critical field is included, and the presence of kinks in $H_{c_1}$ is seen to be related to the elastic instabilities. 29 pages including 16 figures, LaTeX with epsf styl

Correlation of Beam Electron and LED Signal Losses under Irradiation and Long-term Recovery of Lead Tungstate Crystals

Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystals recovery from such damage.Comment: 9 pages, 6 figures, LaTeX2

LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter Prototype

We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70 GeV accelerator complex at Protvino, Russia.Comment: 12 pages, 8 figures, LaTeX2e, revised versio

Comparison of Radiation Damage in Lead Tungstate Crystals under Pion and Gamma Irradiation

Studies of the radiation hardness of lead tungstate crystals produced by the Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of Ceramics in China have been carried out at IHEP, Protvino. The crystals were irradiated by a 40-GeV pion beam. After full recovery, the same crystals were irradiated using a $^{137}Cs$ $\gamma$-ray source. The dose rate profiles along the crystal length were observed to be quite similar. We compare the effects of the two types of radiation on the crystals light output.Comment: 10 pages, 8 figures, Latex 2e, 28.04.04 - minor grammatical change