The new experimental setup TANGRA (Tagged Neutrons & Gamma Rays), for the investigation of neutron induced nuclear reactions, e.g. (n,xn’), (n,xn’γ), (n,γ), (n,f), on a number of important isotopes ...for nuclear science and engineering (235,238U, 237Np, 239Pu, 244,245,248Cm) is under construction and being tested at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR) in Dubna.
The TANGRA setup consists of: a portable neutron generator ING-27, with a 64-pixel Si charge-particle detector incorporated into its vacuum chamber for registering of α-particles formed in the T(d, n)4He reaction, as a source of 14.1 MeV steady-state neutrons radiation with an intensity of ∼5x107n/s; a combined iron (Fe), borated polyethylene (BPE) and lead (Pb) compact shielding-collimator; a reconfigurable multi-detector (neutron plus gamma ray detecting system); a fast computer with 2 (x16 channels) PCI-E 100 MHz ADC cards for data acquisition and hard disk storage; Linux ROOT data acquisition, visualization and analysis software. The signals from the α-particle detector are used to ‘tag’ the neutrons with the coincident α-particles. Counting the coincidences between the α-particle and the reaction-product detectors in a 20ns time-interval improves the effect/background-ratio by a factor of ∼200 as well as the accuracy in the neutron flux determination, which decreases noticeably the overall experimental data uncertainty.
The tagged neutron technique (TNT) is analyzed in terms of its application for detecting dangerous substances hidden in underwater objects. The use of the technique for solving these problems is ...justified theoretically. The main characteristics of a prototype detector aimed at detecting explosives in a water environment are determined.
Results of measurements of heavy hyperon and antihyperon yields in deep inelastic muon scattering obtained in the COMPASS experiment and their matching with Monte Carlo predictions are presented. ...Those of relative yields of heavy hyperons Σ(1385)
+
, Σ(1385)
−
,
,
, Ξ(1321)
−
,
with respect to Λ and
baryons were used to optimize the LEPTO/JETSET generator, which is heavily exploited for event simulation in a deep inelastic scattering region.
Abstract
The
Ammonium
prediction in river water and the
Phosphate
prediction in river water datasets (provided by the Ukrainian government) have been handled. The ARIMA (p, d, q) model of low order ...(p<5 and q<5) and high-order models (p>4 or q>4) have been constructed to describe behaviour of concentration time series at different river stations. Orders and coefficients in the first case are obtained via information criteria minimization. In the second case the ACF and PACF functions analysis is used. The ArDL(p, q) models are used to investigate correlation between concentrations of ammonium and phosphates at different river stations. Dependence of these parameters at the target water station and at other stations is confirmed with statistical tests. Conclusions about water pollution are made.
Mathematical models of water pollution evaluation Drozdov, I. Yu; Aleksakhin, A. V.; Aleksakhina, Yu.V. ...
IOP conference series. Earth and environmental science,
03/2021, Letnik:
684, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
BOD (Biological Oxygen Demand or Biochemical Oxygen Demand) is the amount of dissolved oxygen, expressed e.g. in milligrams of oxygen per dm
3
of water, consumed by micro-organisms to ...decompose the organic matter present in water. Ammonium and phosphate contamination prediction in river water and BOD in river water prediction datasets (provided by the Ukrainian government) have been handled. The paper presents proposal of linear regression models (configured with the Ordinary Least Squares (OLS) method) describing dependencies between the target water station and the test station values. The mutual influence between amounts of ammonium and phosphates in river water has been shown The ArDL(p, q) models were used to investigate correlation between concentrations of phosphates and value of BOD at the target river station. Influence of phosphates amount on the BOD in river water has been proven with statistical tests.
Using natural gas as an additional fuel in a blast furnace is known to reduce coke consumption during blast-furnace production. In a standard tuyere, the hot blast pushes the natural gas up against ...the surface of the blast duct, resulting in poor mixing between the natural gas and the hot blast, which in turn leads to incomplete combustion and pyrolysis of the natural gas. One approach for improving mixing between the natural gas and the hot blast is to modify the blast-channel geometry.
An engineering design solution was proposed, and the gas dynamics, thermal conditions, and stress/strain state of the air tuyere for this solution were analyzed via ANSYS modeling. Toroidal protrusions on an insert near the outlet of the air tuyere (swirlers) or on the gas inlet nozzle flange (rim) were considered; these protrusions also protect the insert against premature damage in areas subject to the most severe mechanical damage.
The following assumptions were made: The model scope includes both the fluid medium within the blast duct and the thermal insulation insert, i.e., this can be thought of as a conjugate heat exchange problem, and heat transfer to the cooling system water was taken into account using the generalized boundary conditions.
We show that modifying the insert geometry so that there is a protrusion on the working surface or installing a rim in the area where the insert starts to show damage, will increase mixing of the natural gas into the blast air and during combustion. This then increases the blast temperature at the tuyere outlet, which in turn increases the natural-gas flow rate and reduces coke usage. A similar result was achieved for wear on the insert.
This study is aimed at identifying the best values for the parameters of energy efficient digital development of the petroleum and gas sector. Research methods - construction of a production ...function, regression analysis and linear programming. Based on the production function of Cobb-Douglas, the dependence of the sales volumes of the petroleum and gas sector of the economy on the costs of digitalization and labor costs was revealed; the regression analysis method provided the construction of a set of equations describing the impact of the costs of energy resources of petroleum and gas enterprises and the costs of digitalization on the total costs of enterprises for production and sales, the efficiency of using by-products from petroleum production and labor capital; the optimal values of energy-efficient digital resource-saving development of the petroleum and gas sector of the economy have been determined, the achievement of which will ensure a decrease in the energy consumption of processes at the enterprises of the petroleum and gas complex. Thus, connections have been established and the trajectories of energy efficient functioning of the petroleum and gas sector of the economy have been determined. The research results can be applied within the framework of strategies for socio-economic development, sustainable development, as well as digitalization of the petroleum and gas complex and industrial enterprises.
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