159 research outputs found
The dynamic analysis of managing units and sectors of economic and industrial activity
ΠΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ ΠΎΡΠ½ΠΎΠ²Π½Ρ Π·Π°Π»Π΅ΠΆΠ½ΠΎΡΡΡ ΠΌΡΠΆ ΠΏΡΠΎΠ΄ΡΠΊΡΠΈΠ²Π½ΡΡΡΡ ΠΏΡΠ°ΡΡ ΡΠ° ΡΠΎΠ·ΠΌΡΡΠ°ΠΌΠΈ ΠΏΡΠ΄ΠΏΡΠΈΡΠΌΡΡΠ²Π°.The main dependences between labor productivity and the sizes of the enterprise and company are defined in this work
INVESTIGATION OF TWO-PHASE FLOW HYDRODYNAMICS OF HEAT EXCHANGE TUBE OUTLET FALLING FILM EVAPORATOR
Studies of hydrodynamics and heat transfer in falling film evaporators are presented in a significant number of scientific papers [1, 2, 3]. This work is devoted to the study of a distribution of a gas phase velocity and a liquid phase irrigation density at the outlet of the heat exchange tube of the falling film evaporator.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
Simulation method of the low-Re flows in the packed bed technological equipment
The paper shows the semiempirical method of a numerical simulation of the low-Re flows in the packed bed technological apparatus. The proposed method is based on the Navier-Stokes equations modification by the linear momentum sources equations in the packed bed zones. It is found that the simulation error of the proposed method is not more than 6.2% for low-density finite element meshes. The average value of the simulation error is about 3.0% for all shown cases. It was found that the proposed method simulation error almost independents on the mesh density. In the main, the simulation error is determined by the linear momentum sources equations approximation error. Β© Published under licence by IOP Publishing Ltd
INVESTIGATION OF HYDRODYNAMIC PARAMETERS DISTRIBUTION IN HEAT EXCHANGE TUBES OF FALLING FILM EVAPORATOR
Falling film evaporators have a high heat transfer rate with relatively small volumes of the device [1, 2, 3]. It is advisable to have information about changes in hydrodynamic parameters along the length of heat exchange tubes, when developing a falling film evaporator.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
Gadolinium-based hybrid ultra-low-background material for protecting the darkside20k dark matter detector from background neutrons
A laboratory technique was developed for obtaining an ultra-low-background hybrid material based on organic glass - polymethyl methacrylate (PMMA). 157Gd nuclei are used as an efficient absorber of thermal neutrons in the hybrid material. A uniform distribution of gadolinium in the PMMAmatrix is achieved by introducing he gadolinium in the form of a coordination compound -gadolinium acetylacetonate- into the hybrid materia
INVESTIGATION OF THE HYDRODYNAMICS OF MIXING TWO TECHNOLOGICAL MEDIA WITH A SMALL-SIZED AGITATOR
The existing precipitation plant uses a cascade of three reactors connected in series, each with a mixing device and a heat exchanger. Numerical simulation of mixing fluid dynamics was carried out using the ANSYS Fluent CFD code with a standard k-epsilon turbulence model and a mixture model. The study considered a two-phase model with technological media of different densities.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
INVESTIGATION OF THE HYDRODYNAMICS OF MIXING TWO TECHNOLOGICAL MEDIA USING A SIX-BLADE AGITATOR
The precipitation of ammonium polyuranate is carried out in a cascade of reactors equipped with a agitator and a heat exchanger. In the course of this study, the existing mixing device was replaced by a six-blade 3D model of which is shown in Figure 1. Data ere obtained on the distribution of two technological media and flow rates in the volume of the apparatus at different operating modes of the mixing device.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
IMPLEMENTATION OF A HIGH-EFFICIENT ELEMENTARY HEATER IN THE CIRCUIT OF AN EXISTING EVAPORATOR WITH THE PURPOSE OF SAVING HEATING STEAM
he paper gives a brief description of the method for producing alumina (Al2O3) by the Bayer method.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
EXPERIMENTAL STUDIES OF THE PROCESS OF COOLANT EVAPORATION
Cooling lubricants based on triethanolamine (CL) are widely used in metal processing because of need for cooling in the processing area of the product, reducing tool wear, and ensuring quality of the processed surface [1, 2, 3, 4]. It is advisable to pre-concentrate the coolant for disposal.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)
How close can one approach the Dirac point in graphene experimentally?
The above question is frequently asked by theorists who are interested in
graphene as a model system, especially in context of relativistic quantum
physics. We offer an experimental answer by describing electron transport in
suspended devices with carrier mobilities of several 10^6 cm^2V^-1s^-1 and with
the onset of Landau quantization occurring in fields below 5 mT. The observed
charge inhomogeneity is as low as \approx10^8 cm^-2, allowing a neutral state
with a few charge carriers per entire micron-scale device. Above liquid helium
temperatures, the electronic properties of such devices are intrinsic, being
governed by thermal excitations only. This yields that the Dirac point can be
approached within 1 meV, a limit currently set by the remaining charge
inhomogeneity. No sign of an insulating state is observed down to 1 K, which
establishes the upper limit on a possible bandgap
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