Search

We present our observations of electromagnetic transients associated with GW170817/GRB 170817A using optical telescopes of Chilescope observatory and Big Scanning Antenna (BSA) of Pushchino Radio Astronomy Observatory at 110MHz. The Chilescope observatory detected an optical transient of $\sim19^m$ on the third day in the outskirts of the galaxy NGC 4993; we continued observations following its rapid decrease. We put an upper limit of $1.5\times10^{4}$ Jy on any radio source with a duration of 10-60 s which may be associated with GW170817/GRB 170817A. The prompt gamma-ray emission consists of two distinctive components - a hard short pulse delayed by $\sim2$ seconds with respect to the LIGO signal and softer thermal pulse with $T\sim 10 $ keV lasting for another $\sim2$ seconds. The appearance of a thermal component at the end of the burst is unusual for short GRBs. Both the hard and the soft components do not satisfy the Amati relation, making GRB 170817A distinctively different from other short GRBs. Based on gamma-ray and optical observations, we develop a model for the prompt high-energy emission associated with GRB 170817A. The merger of two neutron stars creates an accretion torus of $\sim10^{-2} M_\odot$, which supplies the black hole with magnetic flux and confines the Blandford-Znajek-powered jet. We associate the hard prompt spike with the quasispherical breakout of the jet from the disk wind. As the jet plows through the wind with subrelativistic velocity, it creates a radiation-dominated shock that heats the wind material to tens of kiloelectron volts, producing the soft thermal component., 20 pages, 12 figures

The WWR-M reactor at NRC «Kurchatov Institute» - PNPI is going to be equipped with high-density ultracold neutron source. Method of UCN production is based on their accumulation in the superfluid helium at 1.2 K temperature. Thus, the source will provide the UCN density at EDM spectrometer equals to ρ = 1.3⋅104 cm−3 which is 2 order magnitude greater than the output density of existing UCN source in the world. An extensive program of fundamental researches such as measuring of neutron lifetime and searching of neutron-antineutron oscillation is planned. In addition, CN and VCN beams are going to be equipped with condensed matter physics experimental setups. The design of the UCN source has been completed, complex tests at full-scale model showed that is possible to maintain superfluid helium under reactor heat load; calculations of an UCN source passive shielding, which ensures source safe operation, is completed. At the moment the process of UCN source manufacturing is taking place.

It is proposed to use single-domain rodlike magnetic nanoparticles (MNPs) as mediators for nanomechanical control of properties of biological membranes and cells on the molecular or cellular level by exposing them to a homogeneous nonheating low-frequency magnetic field (AC MF). The trigger effect is achieved due to rotatory-oscillatory motion of MNPs in the AC MF, which causes the needed deformations in macromolecules of the membrane interacting with these MNPs.

A detailed analysis of hydrology, hydrodynamics, and microstructure of an anticyclonic eddy is performed. We use the field data obtained in May 2004 at the shelf edge in the northwestern part of the Black Sea. We study the spatial distributions of the Brunt-Vaisal number, and regions of mixing with a vertical scale on the order of 2 m. Possible mechanisms of generation and maintenance of the observed mixed layers are analyzed. A conclusion is made that the investigated eddy in the northwestern part of the Black Sea (possibly similar to the other natural eddies in the northwestern part of the Black Sea) is able to modify the fine layered structure of the scalar hydrophysical fields in the upper 150-m layer forming and maintaining the layers of low vertical gradients with vertical scales of ∼2 m and up to 50–100 km in the horizontal direction owing to the local shear instability of the horizontal flow.

Now a day the task of comparative analysis of sample sources from different astronomical catalogs is becoming very topical for astronomers. It is useful both for the same spectral range data and for their cross-analysis for different spectral ranges. It is also important, that the real data from astronomical instruments is placed on-line. For the above purposes we are developing a website for the PRAO ASC LPI (www.prao.ru) and, based upon it, the Radio As­tronomy Data Center (RADC). The RADC is a system for storage and processing of radio astronomical data. Here you can find a collection of tools for preparing radio astronomical observations, which includes a base set of main astronomical catalogues useful to radio astronomers, as well as a database of observation results from the Observatory.

One of the most sensitive radio telescopes at the frequency of 110 MHz is a Big Scanning Antenna (BSA) in Pushchino Radio Astronomy Observatory of Lebedev Physical Institute (PRAO LPI, Moscow region, Russia). Since 2012 in the BSA the continuous survey observation was started in multibeam mode in the frequency band of 109–112 MHz. Now 96 beams covering from −8 and up to +42° in declination are used. The number of frequency bands are 6 with a time resolution of 0.1 s and 32 bands with the time resolution of 0.0125 s. In a fast mode (32 bands, 0.0125 s) daily data flow is 87.5 GB (32 TB per year). The data provide a great opportunity for both short-term and long-term monitoring of the various radio sources. The sources are fast radio transients of different nature, such as fast radio bursts (FRB), possible counterparts of gamma-ray bursts (GRB), and sources of gravitational waves, the Earth’s ionosphere, interplanetary and interstellar plasma. Based on the BSA observations the database is constructed. We discuss data base properties, the methods of transient search and allocation in database. Using this database we were able to detect 83096 individual transient events in the period of July 2012 – October 2013, which may correspond to pulsars, scintillating sources and fast radio transients. We also present first results and statistics of transients classification. In particular we report parameters of two candidates in new RRAT pulsars.

A simple 1.5-dimensional model of vertical exchange for heat, salt, and other dissolved substances has been developed for the Cariaco Basin. The model parameters are derived based on the temperature and salinity data collected monthly at a deepwater station in the eastern part of the basin from 1995 through 2007 during the CARIACO time series program. The model describes the processes of turbulent (eddy) diffusion, which includes the integrated effect of diffusive exchange mechanisms acting in the basin, and of vertical advection, which arises following injection of dense water into deep layers following an inflow from the Caribbean Sea. The model takes into account the changes in the horizontal cross-section area of the basin with respect to depth. Temporal variability is an important feature of the hydrography of the Cariaco Basin. To assess profiles of the vertical eddy diffusion coefficient and vertical advection velocity, we examined a time series of CTD profiles (potential temperature and salinity). Two distinct time intervals were identified as the result of this examination. During the first period, the thermohaline structure of the basin was apparently influenced by one or more inflows. The second period, in contrast, showed little or no influence of an inflow. The data from the second period, where no inflows were observed, were incorporated into corresponding transfer equations to assess the profile of the vertical eddy diffusion coefficient, k(z). Then, the result of this assessment was used with the data from the first period to estimate the profile of the vertical advection velocity, W(z), for a time when the effects of an inflow were evident. For that case, the transfer equations include the terms describing the effect of the inflow. Analysis of the vertical profile of the turbulent diffusion coefficient suggests that, in the upper stratified part of the water column, the diffusion mechanism is mostly associated with transient mixing events, which occur due to shear instability in the field of low frequency internal waves. We speculate that below 400 m bottom friction over the sloping bottom and geothermal heat flux play the decisive role in the vertical exchange. Analysis of the W(z) profiles reveals two layers dominated by the entrainment of the ambient fluid into the down flow of dense water from the Caribbean Sea, and two layers where this down flow breaks down through the formation of isopycnal intrusions.

In the following paper we suggest the principles of structural, infological and dynamic modeling of processes within a functioning enterprise, allowing to effectively plan its strategic development and assure its sustainable functioning. We offer a new interpretation of sustainable development of an enterprise, based on separating the concepts of sustainability and development, and apply the concepts taken from reliability engineering to the functioning of an enterprise. The principles, methods and models described in the paper may serve as the basis for the automation of management and strategic planning of businesses based on cloud technologies.

The article is devoted to recreational opportunities of forest ecosystems of Clinsko-Dmytrovskaja Grjada. Recreational potential in connection of forest types was given as result of male study. As a result of studies is assessed the recreational potential in relation to forest types. The impact of various forms of rechation on the state of the main elements of the forest has been given. The description of flora and fauna have been given.

The WWR-M reactor at PNPI is planned to be equipped with a high-flux source for ultracold neutrons (UCNs). The method of UCN production is based on neutron conversion in superfluid helium, exploiting the particular qualities of that quantum liquid. As a result of optimizing the source parameters, we expect a temperature of superfluid helium of 1.2 K and a UCN density of 1.3 × 104 cm−3 in a neutron electric dipole moment (EDM) spectrometer. The expected flux densities of cold neutrons (with wavelengths in the range 2–20 Å) and very cold neutrons (50–100 Å) at the output of a neutron guide with a cross section of 30 × 200 mm2 are 9.7 × 107 cm−2s−1 and 8.3 × 105 cm−2s−1, respectively. The capability of maintaining a temperature of 1.37 K at a thermal load of 60 W was shown experimentally, while the theoretical load is expected to be 37 W. Calculations show that it is possible to decrease the helium temperature down to 1.2 K at similar heat load. The project includes the development of experimental stations at UCN beams, such as for a neutron EDM search, measurements of the neutron lifetime, and for a search for neutron-to-mirror-neutron transitions. In addition, three beams of cold and very cold neutrons are foreseen. At present, the vacuum container of the UCN source has been manufactured and the production of the low-temperature deuterium and helium parts of the source has been started.

The WWR-M reactor at PNPI is going to be equipped with an ultacold neutron source of high density. Method of UCN production is based on their accumulation in the super fluid helium due to particular qualities of that quantum liquid. The possibility of maintaining the temperature T = 1.371K with a thermal load of P = 60W was shown experimentally, while the theoretical load is expected to be P=30W. The project envisages the installation on UCN beams the experimental setups of various research projects such as searching for the nEDM, measure the neutron lifetime, and the observation of neutron to antineutron oscillation. In addition to UCN beams, three beams of cold and verycold neutrons are planned. Six experimental setups will be installed on these beams. At present, a vacuum container of the UCN source has been manufactured and the manufacture of low-temperature deuterium and helium parts of the source has been started.

Heterogeneous nucleation of vapor on a seed particle surface is dependent on the seed properties such as size, chemical composition, and electric charging state, of which the significance of the charging state has not been uncovered unambiguously. The underlying problem is that, on the molecular level, the charging state and the chemical composition of the seed are connected and cannot be well separated without a direct mass spectrometric measurement of the ion. By generating sub-3 nm size selected seeds of different size, chemical composition, electric charging state, and letting three different vapors nucleate onto the seeds, we show that heterogeneous nucleation does not clearly prefer either positive or negative seeds. Rather, the most important parameter determining the nucleation probability in the sub-3 nm size range was the seed chemical composition. Our findings help to understand the dynamics in various nanoparticle systems, such as nucleation chambers, industrial processes, or atmospheric aerosols.

The paper presents analytical studies of the torque motor tape active element. The tape active element is a novel type of a motor’s stator organization, where the conventional winding is replaced by a tape winding. Given the operation principle of proposed active element; its torque characteristics are then computationally found with using the finite element method (FEM). The results show the possibility of the optimal value of the relative electrode width, when the torque will be maximal. The analytical studies of the motor’s torque over the number of tape winding coils allowed to receive the recommendations on choosing the number of coils.