The possibility of separating quark and gluon jets in heavy ion collisions, both in the presence of the jet quenching effect and in its absence, has been investigated. Using machine learning methods, ...a technique has been developed to recover the fraction of quark and gluon jets, using variables characterizing the shape, multiplicity, and charge of the jet. The potential of using these variables to study the characteristics of the dense medium that arises during high-energy ion collisions has been demonstrated.
Precise estimation of the effective petrophysical characteristics for the oil or gas-bearing reservoir plays a vital role in production control problems. It is preferable to use nondestructive ...measurement methods for porosity, conductivity, geomechanical modulus, and some other parameter fields. For the estimation of anisotropic permeability tensor flows in different directions need to be simulated in the core plug digital image void space, which is very difficult (if possible) to conduct with the real rock sample. The creation of the digital core image includes three stages: construction of its internal structure based on the computed tomography (CT) sinogram, filtration, and segmentation. Routine practice is the filtration of 2D slices pack of the core plug CT image because of a lack of computational power and memory limitations. Unfortunately, this can generate a directional orientation error orthogonal to the pack of slices. The total 3D edge-preserving filtration with the usage of two approaches: modified implicit anisotropic diffusion and discrete orthogonal transforms can reduce this error. Universal code based on the MPI+OpenAcc programming paradigm was tested on different high-performance computing systems incorporating various accelerators like GPGPU and heterogeneous processors such as Sunway 26010.
In the construction designing of oil field surface facilities, exists a problem of the seabed production equipment optimal placement. As an initial approximation, we can represent this task in the ...form of the linear Boolean programming problem. An application of routine methods of discrete programming can theoretically give the desired solution. However, these methods do not take into account the specific nature of the problem. This problem belongs to the NP class. So we can run into significant computational difficulties. This situation is typical for construction of the ground surface or subsea located facilities for real oil/gas fields. To overcome it, we propose to replace a discrete programming model with a linear programming one, which takes into account problem-specific properties. Also, we present examples of the application of the proposed parallel optimization algorithms. Input data for them: the seabed profile, geometry, and space distribution of oil/gas reserves. Optimization problem objective function is the penalty for the irrational placement of seabed production equipment elements.
The structure and mechanical properties of a number of experimental 12% chromium steels of the ferritic-martensitic class are studied, whose prototypes are two domestic heat-resistant steels EP-450 ...(12Kh12М2BFR) and EP-823 (16Kh12МVSFBR). The possibility is demonstrated of using isothermal hardening for controlling the quantitative ratio of martensite and ferrite in test steel structure, characterized by considerable austenite thermal stability. It is established that ferrite content in the original steel structure has a specific unfavorable effect on high-temperature strength.
This paper is devoted to the studies of the T-10 plasma impurity composition during experimental campaigns of 2014–2016, when a carbon limiter was replaced by a tungsten one and a movable lithium ...limiter was installed. In these experiments, the effective charge of the plasma was determined from the bremsstrahlung intensity and from CXRS measurements. The total concentration of tungsten ions in the column was estimated from the intensity of the radiation detected by AXUV. The source of light impurities (C, N, O, Li), as well as of tungsten atoms, was estimated from absolute measurements of line emission profiles. The experiment showed that the use of lithium as a limiter material can significantly reduce the flow of light impurities into the discharge and also reduce the dispersion of the W diaphragm. At the same time, the concentration of lithium nuclei in the column does not reach values measurable by CXRS diagnostics of the T-10 (0.3–0.5% of the plasma density).
On the basis of data on proton–proton collisions at the energy
s
= 8 TeV and with the integrated luminosity of 19.8 fb
–1
, the resolution of the transverse momentum and the uncertainty of the energy ...scale were estimated for jets that were reconstructed using the Jet-Plus-Track algorithm. The performance of the algorithm for the identification of jets that originated from the signal event and the separation of jets into quark and gluon jets was also assessed.
This article describes the vacuum system of the KTM tokamak and also presents an algorithm for the technological mode of conditioning of the tokamak vacuum chamber (VC) performed before and during ...the experiment and its influence on production of glow discharges. The applied procedure of the vacuum chamber preparation, despite the atmospheric leakage in 2021, provided the possibility to develop conditions for conducting experiments at the KTM tokamak and to obtain discharges with the highest currents and discharge durations for this facility achievable at the time of writing of this article. As a result of the analysis of experimental data, the conditions have been established under which plasma discharges are not formed.
In 19551961, a fuel element with cladding made from ferrite-martensite steel for use in lead-bismuth coolant was developed at the Leipunskii Institute for Physics and Power Engineering (FEI) under ...the direction of V. A. Malykh. The solution of an important federal problem, viz., the development of fast nuclear submarines, also became possible after the original development of the fuel element 1. Ferrite-martensite class steel with 12% chromium content, which is used as a structural material in fast reactors, continued to be improved in subsequent years. One direction of the new technological platform, which has now been adopted in the State Corporation Rosatom, is the development of innovative fast reactors with intense temperature and dose loads, using lead, lead-bismuth and sodium as coolant. In this connection, the development of ferrite-martensite steel, possessing enhanced strength and plasticity, has not lost its urgency. The determination of the optimal chemical composition and heat-treatment conditions is complicated by the multifactor nature and nonlinearity of the problem. Research in this field can be intensified on the basis of modern methods of multidimensional statistical analysis of experimental data and neural net modeling 2, 3. The development and application of methods oriented toward massive calculations are largely due to the increase in the computational power of modern computers.
Abstract
Lack of petrophysical information is critical for reservoirs development composed of poorly consolidated rocks or for zones bearing wells with core damaged by improper coring operations. The ...restoration complexity of the digital-core lost sections is associated with the need to consider an enormous amount of data from the existing core image and the necessity to include lithological expert knowledge. That makes deep learning methods a natural choice for solving such problems. We proposed, examined, and compared several deep learning methods convenient for analyzing micro-computed tomography digital core data. It was done under the most simplistic problem statement when the destroyed part (a set of slices) is completely lost. Here, we present the results of comparison interpolation/extrapolation procedures under proposed quality metrics. We discover that the variational autoencoder method can be trained to extract some petrophysical parameters from the digital core plug in an unsupervised manner.
The results of an investigation of the short-time mechanical properties of two batches of experimental ferrite-martensite alloys with 12% chromium content are presented. The chemical composition of ...the alloys was calculated with a neural-net model developed using data from tests performed on samples of EI-852, EP-450, EP-823, and EP-900 steels. Analysis showed that one of the melted alloys has a high yield stress in the test temperature range 20–720°C. A second version of the neural net model was developed using test data obtained for experimental samples with elevated manganese content.
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