Calculation Of Corrections Research Articles

The ANALYSIS of the MECHANICAL PROPERTIES of REGIONAL PIPELINES

Piston pumps and compressors are widely used for exploration and transportation of oil and gas. Piston machines are heavy-duty systems that are still failure prone due to high stresses and wear proses. Increasing the efficiency and durability of the piston compressors, pumps, internal combustion engines, etc. directly depends on the correct calculations and designing of these elements. Using ANSYS software, simulation and stress analysis are performed on the basis of the 405GP15/70 and ARIEL heavy-duty balanced opposed piston compressors used in the Caspian Sea-Black Sea Region. During working of the machines and equipment a number of the processes interconnected and causing each other are proceeds (dynamic processes, wear of the interfaced details, change of mechanical properties of materials, etc.). Improvement of modelling of technical condition of cars and mechanisms on a multicriteria basis is one of the actual directions of modern engineering science. The improvement of methods of modelling of change of technical conditions of the piston mechanisms taking into account interrelation of dynamic characteristics, the wear interfaced details and the diagnosed mechanical parameters considered in this article. By observing the analysis results, we can decide whether our designed pipelines are safe or not under applied load conditions. The durable and reliable work of compressor-pump stations used in the oil and gas industry has great importance for practice. Investigation of complex problems with respect to friction and wear (clearances), stresses, and thermodynamics phenomena in the piston machines, and oil and gas pipelines gives the opportunity to solve the problems of increasing the durability of these machines and pipelines. Confirmation that the new methodologies can be produced by the current supply chain improving manufacturing efficiency and reducing the environmental and social impact of the supply chain.

Eksplorasi kemampuan penalaran visual siswa pada materi perbandingan trigonometri ditintau dari gender

The aim of this research is to analyze the visual reasoning abilities of high school students based on gender using trigonometry comparison material. The subject consists of two students with the provisions of one male student and one female student. Data was collected by administering a visual reasoning test to 10 10th grade students, then the selected subjects were interviewed. The data validation used is the triangulation method. Data analysis techniques use data reduction, data presentation and conclusion drawing. The results of the research showed that male students in the trigonometry comparison material were able to identify side sides, slanted sides, front sides, and were able to determine the use of the cos and tan formulas to solve problems with correct calculations. Meanwhile, female students in the trigonometry comparison material were able to identify side sides, slanted sides, front sides, were able to determine the use of the cos and tan formulas, but were less precise in determining the value of cos 30°, and less precise in making the final decision because they did not convert it into units. the same thing, namely meters.

ЕЛЕКТРОННИЙ ЖУРНАЛ ЯК ІНСТРУМЕНТ ЦИФРОВОЇ ОСВІТНЬОЇ КОМУНІКАЦІЇ: РЕЗУЛЬТАТИ ВСЕУКРАЇНСЬКОГО ОПИТУВАННЯ

The article provides a definition of digital educational communication and considers the issue of using an electronic class register in general secondary education institutions as a digital tool necessary for organizing the educational process in modern conditions. The main advantages and features of the implementation of an electronic class register during distance learning are highlighted. The results of an all-Ukrainian survey of pedagogical workers regarding the use of electronic class register were analyzed and given, during which attention was paid to such aspects as: convenience, correspondence of electronic class register to the paper version, efficiency of using the digital tool, available sections and functionality. On a positive note, the majority of respondents are adopting electronic class registers and consider them to be a necessary tool nowadays, with about half of respondents indicating that they help teachers use their working time effectively. On the other hand, the study shows that the use of electronic class registers has a downside, such as duplicating information on paper, which is required by the administration of the educational institutions, and that is a waste of time. It was found that almost all electronic class registers need some improvement. It was established that they lack some sections, a mobile application or its limited functions or an inconvenient interface, the lack of an opportunity to generate a new sample report card (NUSH), as well as existing problems with the division of the class into subgroups, the correct calculation of the thematic evaluation, transfer of evaluations when a student is transferred to another class or a subgroup, etc. Attention is focused on the need for developers to take into account the comments of practicing teachers in order to improve the quality of a modern digital tool. In general, the results of the study indicate the expediency of involving pedagogical workers in the design of electronic class registers in the future and the need to make certain decisions regarding the improvement of the legal framework for the control of this digital tool and the proper preservation of personal data of students at the state level.

One-loop corrections to the double-real emission contribution to the zero-jettiness soft function at N3LO in QCD

We present an analytic calculation of the one-loop correction to the double-real emission contribution to the zero-jettiness soft function at N3LO in QCD, accounting for both gluon-gluon and quark-antiquark soft final-state partons. We explain all the relevant steps of the computation including the reduction of phase-space integrals to master integrals in the presence of Heaviside functions, and the methods we employed to compute them.

Analysis of the frictional processes in piston machines

The durable and reliable work of piston compressors and pumps used in the oil and gas industry has great importance for practice. Investigation of complex problems with respect to mechanical and thermodynamic phenomena in compressors and pumps gives the opportunity to solve the problems of increasing the durability of oil and gas exploitation and transportation. Increasing the efficiency and durability of the compressor-pump stations directly depends on the correct calculations and designing of the different elements and mechanical parameters of piston machines. The problem of determining the forces affecting the crank-piston mechanisms of the piston compressors arises during the study of the friction process in the working parts, as well as the study of the oscillating movement of the moving crankshaft of this compressor. The indicated forces periodically depend on the angle, time, and rotation of the crankshaft of this compressor, as a result of which they create forces at various nodes of the piston mechanism and the shaft of the compressor machine. These specified conditions can create dangerous stresses that can cause the compressor connecting rod and crankshaft to break. In this work, in terms of its special characteristics, the forces affecting the piston compressor's lever-slider mechanism are determined by taking into account the main factors accompanying the working process. The results of the investigation can be useful for the design and exploitation of compressor stations used in the oil and gas industry.

Theoretical investigation of the silver chalcogenide molecules AgSe and AgTe electronic structure with dipole moment calculation

The spectroscopic constants (Re, Te, ωe, Be) are determined for 46 doublet and quartet low-lying states of the molecules AgTe and AgSe using CASSCF/MRCI (single and double excitations plus Davidson correction) calculations. The equilibrium bond length Re, and the vibrational frequency ωe of the ground state of both molecules have also been investigated using the density functional theory (DFT) incorporating eight different functionals along with different basis sets. The potential energy and permanent dipole moment curves of 23 states of each molecule have been investigated and depicted. This study represents the first theoretical investigation of the molecules AgSe and AgTe.

Predicting solvation energies of free radicals and their mixtures: A robust approach coupling the Peng-Robinson and COSMO-RS models

Detailed kinetic models are valuable tools for a clear understanding of the dynamics of complex reacting systems based on radical-chain mechanisms, such as combustion and oxidation. Gas-phase automatic kinetic generators, such as EXGAS, RMG, MAMOX, NetGen, REACTION, and GENESYS can be used to establish a detailed network of reaction pathways and the rates associated with each reaction. The range of applications of these gas-phase kinetic generators can be extended to liquids through diffusional and solvation corrections directly applied to the gas-phase thermo-kinetic data. In this work, a flexible framework is proposed for the calculation of the solvation correction involving closed-shell (i.e., non-free radical) and open-shell (i.e., free radicals) molecules. This novel model relies on the Peng-Robinson cubic equation of state (EoS) combined with a quantum-based continuum solvation model (COSMO-RS) through an advanced mixing rule. Unlike most predictive equations of state, the proposed model requires only pure compound inputs: critical temperature (Tc,i), critical pressure (Pc,i), acentric factor (ωi), and the screening charge distribution (σ-profile). These inputs were obtained for C/H/O free radicals using group corrections applied to the known values of the associated closed-shell molecules (parent molecules). The resulting EoS is able to provide fast predictions of solvation quantities of closed-shell molecules and C/H/O free radicals with a mean unsigned error of around 0.30 kcal/mol. The great advantage of this method is that it allows high-throughput computation of solvation quantities in pure solvents and mixtures at any temperature (including the supercritical domain), which could enable the simulation of complex oxidation kinetics in a wide range of applications.

Cosmological correlators in massless ϕ4-theory and the method of regions

The calculation of loop corrections to the correlation functions of quantum fields during inflation or in the de Sitter background presents greater challenges than in flat space due to the more complicated form of the mode functions. While in flat space highly sophisticated approaches to Feynman integrals exist, similar tools still remain to be developed for cosmological correlators. However, usually only their late-time limit is of interest. We introduce the method-of-region expansion for cosmological correlators as a tool to extract the late-time limit, and illustrate it with several examples for the interacting, massless, minimally coupled scalar field in de Sitter space. In particular, we consider the in-in correlator 〈ϕ2(η, q)ϕ(η, k1)ϕ(η, k2)〉, whose region structure is relevant to anomalous dimensions and matching coefficients in Soft de Sitter effective theory.

Numerical 1-loop correction from a potential yielding ultra-slow-roll dynamics

Single-field models of inflation might lead to amplified scalar fluctuations on small scales due, for example, to a transient ultra-slow-roll phase. It was argued by Kristiano & Yokoyama in ref. [1] that the enhanced amplitude of the scalar power spectrum on small scales has the potential to induce a sizeable 1-loop correction to the spectrum at large scales. In this work, we repeat the calculation for the 1-loop correction presented in ref. [1]. We closely follow their assumptions but evaluate the loop numerically. This allows us to consider both instantaneous and smooth transitions between the slow-roll and ultra-slow-roll phases. In particular, we generate models featuring realistic, smooth evolution from an analytic inflationary potential. We find that, upon fixing the amplitude of the peak in the power spectrum at short scales, the resulting 1-loop correction is not significantly reduced by considering a smooth evolution. In particular, for a power spectrum with a tree-level peak amplitude potentially relevant for small-scale phenomenology, e.g. primordial black hole production, the 1-loop correction on large scales is a few percent of the tree-level power spectrum.

Comparative analysis of optotypes of Sivtsev, Golovin tables and infrared videonystagmography

Visiometry is one of the fundamental diagnostic methods for assessing visual acuity, including the evaluation of the effectiveness of eye pathology treatment. Therefore, a precise determination of visual acuity is crucial. For a long time, visual acuity has been determined by reading optotypes on optometric charts (in Russia and the CIS countries, the Sivtsev — Golovin chart is the most widely used). With the advancement of “Eye tracking” technologies and the development of high-frequency and detailed monitors, it has become possible to determine visual acuity using induction of normal physiological nystagmus, followed by an analysis and conclusion about the presence of nystagmus on specific presented optotypes. One of the key factors in the accuracy of visual acuity determination is the correct calculation of the size and movement of optotypes, which is analyzed in this review.

Туристік бизнесті дамытудағы ақпараттық жүйелер, интернет-платформалардың алатын орны

Digitalization of all sectors, especially economic sectors, in the country makes it possible to take leading positions on the world stage, as well as improve the quality of life of citizens and create favorable conditions for the development of entrepreneurship. A dynamically developing tourism business with large incomes in the economic sphere is also engaged in digitalization. The mass introduction of digital technologies will give impetus to the development of traditional basic industries by improving the quality of services, increasing their competitiveness, including on the international market. Thus, as a result of digitalization, the provision of top-level services in the tourism sector will be ensured, which, in turn, will lead to a positive formation of the country's tourist image and capital growth. Digitalization of the tourism business optimizes the problem, although it does not solve all the problems. For example, in the field of tourism, if information is provided without correct statistical calculations, then state support measures will also not be directly adjusted. And with the help of digitization, many adjustments and deviations in information can be avoided.

Analytical calculations of the tenth order QED radiative corrections to lepton anomalies within the Mellin–Barnes representation

We investigate the radiative QED corrections to the lepton (L = e, μ and τ) anomalous magnetic moment due to the contributions of diagrams with insertions of the photon vacuum polarisation operator consisting solely of four closed lepton (l = e, μ and τ) loops. Moreover, we focus on specific operators with two loops formed by leptons L of the same type as the external one, the other two formed by leptons ℓ different from L. The approach is essentially based on the employment of the Mellin–Barnes representation of the x-parametrization of the corresponding Feynman diagrams. This allows one to obtain, for the first time, exact analytical expressions for the radiative corrections of the tenth order w.r.t. the electromagnetic coupling constant e. Analytically, the radiative corrections are expressed in terms of the ratio r = m ℓ /m L of the internal to external lepton masses. The dependence on r is investigated numerically in the whole interval of r, 0 < r < ∞ . To make comparisons with earlier published results possible, our exact analytical expressions are expanded as r → 0 and r → ∞ and compared with the corresponding asymptotic expansions known in the literature.

Dispersion Control over Molecule Cohesion: Exploiting and Dissecting the Tipping Power of Aromatic Rings.

ConspectusWe have learned over the past years how London dispersion forces can be effectively used to influence or even qualitatively tip the structure of aggregates and the conformation of single molecules. This happens despite the fact that single dispersion contacts are much weaker than competing polar forces. It is a classical case of strength by numbers, with the importance of London dispersion forces scaling with the system size. Knowledge about the tipping points, however difficult to attain, is necessary for a rational design of intermolecular forces. One requires a careful assessment of the competing interactions, either by sensitive spectroscopic techniques for the study of the isolated molecules and aggregates or by theoretical approaches. Of particular interest are the systems close to the tipping point, when dispersion interactions barely outweigh or approach the strength of the other interactions. Such subtle cases are important milestones for a scale-up to realistic multi-interaction situations encountered in the fields of life and materials science. In searching for examples that provide ideal competing interactions in complexes and small clusters, aromatic systems can offer a diverse set of molecules with a variation of dispersion and electrostatic forces that control the dominant and peripheral interactions. Our combined spectroscopic and theoretical investigations provide valuable insights into the balance of intermolecular forces because they typically allow us to switch the aromatic substituent on and off. High-resolution rotational spectroscopy serves as a benchmark for molecular structures, as correct calculations should be based on correct geometries. When discussing the competition with other noncovalent interactions, obvious competitors are directional hydrogen bonds. As a second counterweight to aryl interactions, we will discuss aurophilic/metallophilic interactions, which also have a strong stabilization with a small number of atoms involved. Vibrational spectroscopy is most sensitive to interactions of light atoms, and the competition of OH hydrogen bonds with dispersion forces in a molecular aggregate can be judged well by the OH stretching frequency. Experiments in the gas phase are ideal for gauging the accuracy of quantum chemical predictions free of solvent forces. A tight collaboration utilizing these three methods allows experiment vs experiment vs theory benchmarking of the overall influence of dispersion in molecular structures and energetics.

The rise and fall of stretched bond errors: Extending the analysis of Perdew-Zunger self-interaction corrections of reaction barrier heights beyond the LSDA.

Incorporating self-interaction corrections (SIC) significantly improves chemical reaction barrier height predictions made using density functional theory methods. We present a detailed orbital-by-orbital analysis of these corrections for three semi-local density functional approximations (DFAs) situated on the three lowest rungs of Jacob's ladder of approximations. The analysis is based on Fermi-Löwdin Orbital Self-Interaction Correction (FLOSIC) calculations performed at several steps along the reaction pathway from the reactants (R) to the transition state (TS) to the products (P) for four representative reactions selected from the BH76 benchmark set. For all three functionals, the major contribution to self-interaction corrections of the barrier heights can be traced to stretched bond orbitals that develop near the TS configuration. The magnitude of the ratio of the self-exchange-correlation energy to the self-Hartree energy (XC/H) for a given orbital is introduced as an indicator of one-electron self-interaction error. XC/H = 1.0 implies that an orbital's self-exchange-correlation energy exactly cancels its self-Hartree energy and that the orbital, therefore, makes no contribution to the SIC in the FLOSIC scheme. For the practical DFAs studied here, XC/H spans a range of values. The largest values are obtained for stretched or strongly lobed orbitals. We show that significant differences in XC/H for corresponding orbitals in the R, TS, and P configurations can be used to identify the major contributors to the SIC of barrier heights and reaction energies. Based on such comparisons, we suggest that barrier height predictions made using the strongly constrained and appropriately normed meta-generalized gradient approximation may have attained the best accuracy possible for a semi-local functional using the Perdew-Zunger SIC approach.

Reweighting from Molecular Mechanics Force Fields to the ANI-2x Neural Network Potential.

To achieve chemical accuracy in free energy calculations, it is necessary to accurately describe the system's potential energy surface and efficiently sample configurations from its Boltzmann distribution. While neural network potentials (NNPs) have shown significantly higher accuracy than classical molecular mechanics (MM) force fields, they have a limited range of applicability and are considerably slower than MM potentials, often by orders of magnitude. To address this challenge, Rufa et al. [Rufa et al. bioRxiv 2020, 10.1101/2020.07.29.227959.] suggested a two-stage approach that uses a fast and established MM alchemical energy protocol, followed by reweighting the results using NNPs, known as endstate correction or indirect free energy calculation. This study systematically investigates the accuracy and robustness of reweighting from an MM reference to a neural network target potential (ANI-2x) for an established data set in vacuum, using single-step free-energy perturbation (FEP) and nonequilibrium (NEQ) switching simulation. We assess the influence of longer switching lengths and the impact of slow degrees of freedom on outliers in the work distribution and compare the results to those of multistate equilibrium free energy simulations. Our results demonstrate that free energy calculations between NNPs and MM potentials should be preferably performed using NEQ switching simulations to obtain accurate free energy estimates. NEQ switching simulations between the MM potentials and NNPs are efficient, robust, and trivial to implement.

The colourful antenna subtraction method

We present a general subtraction scheme for NNLO calculations in massless QCD: the colourful antenna subtraction method. It is a reformulation of the antenna subtraction approach designed to address some of the limitations of the traditional framework, especially aiming at high-multiplicity processes. In the context of the new formalism, structures needed to locally subtract the infrared-divergent behaviour of real emission corrections are systematically inferred from virtual subtraction terms, relying on the cancellation of infrared singularities and on the correspondence between integrated and unintegrated antenna functions. We illustrate in detail how the colourful antenna subtraction method works up to NNLO. The algorithm is particularly suited to be fully automated for the generation of NNLO subtraction terms for generic processes. We employ the new formalism to assemble the subtraction terms required for the calculation of the NNLO correction to hadronic three-jet production and describe their validation procedure.

Cluster perturbation theory IX: Perturbation series for the coupled cluster singles and doubles ground state energy.

In this paper, we develop and analyze a number of perturbation series that target the coupled cluster singles and doubles (CCSD) ground state energy. We show how classical Møller-Plesset perturbation theory series can be restructured to target the CCSD energy based on a reference CCS calculation and how the corresponding cluster perturbation series differs from the classical Møller-Plesset perturbation series. Subsequently, we reformulate these series using the coupled cluster Lagrangian framework to obtain series, where fourth and fifth order energies are determined only using parameters through second order. To test the methods, we perform a series of test calculations on molecular photoswitches of both total energies and reaction energies. We find that the fifth order reaction energies are of CCSD quality and that they are of comparable accuracy to state-of-the-art approximations to the CCSD energy based on local pair natural orbitals. The advantage of the present approach over local correlation methods is the absence of user defined threshold parameters for neglecting or approximating contributions to the correlation energy. Fixed threshold parameters lead to discontinuous energy surfaces, although this effect is often small enough to be ignored, but the present approach has a differentiable energy that will facilitate derivation and implementation of gradients and higher derivatives. A further advantage is that the calculation of the perturbation correction is non-iterative and can, therefore, be calculated in parallel, leading to a short time-to-solution.

Thermal corrections to Rényi entropy in BMS field theory

In the study of three-dimensional flat holography, the BMS field theory manifests the infinite-dimensional BMS3 symmetry, a powerful tool in elucidating numerous universal phenomena. This paper explores a certain low-temperature limit of the BMS field theory. The primary focus lies in the calculation of the thermal correction to the Rényi entropy of the single interval on the cylinder from the replica trick and the uniformizing map. As a double check, an alternative method calculating the entanglement entropy is introduced, with the entanglement first law and the modular Hamiltonian.

Dose and compositional dependence of irradiation-induced property change in FeCr

Ferritic/martensitic steels will be used as structural components in next generation nuclear reactors. Their successful operation relies on an understanding of irradiation-induced defect behaviour in the material. In this study, Fe and FeCr alloys (3–12%Cr) were irradiated with 20 MeV Fe-ions at 313 K to doses ranging between 0.00008 dpa to 6.0 dpa. This dose range covers six orders of magnitude, spanning low, transition, and high dose regimes. Lattice strain and hardness in the irradiated material were characterised with micro-beam Laue X-ray diffraction and nanoindentation, respectively.Irradiation hardening was observed even at very low doses (0.00008 dpa) and showed a monotonic increase with dose up to 6.0 dpa. Lattice strain measurements of samples at 0.0008 dpa allow the calculation of equivalent Frenkel pair densities and corrections to the Norgett-Robinson-Torrens (NRT) model for Fe and FeCr alloys at low dose. NRT efficiency for FeCr is 0.2, which agrees with literature values for high irradiation energy. Lattice strain increases with dose up to 0.8 dpa and then decreases when the damage dose is further increased. The strains measured in this study are lower and peak at a larger dose than predicted by atomistic simulations. This difference can be explained by taking temperature and impurities into account.

Quantum circuit distillation and compression

Quantum coherence in a qubit is vulnerable to environmental noise. When long quantum calculation is run on a quantum processor without error correction, the noise causes fatal errors and messes up the calculation. Here, we propose quantum-circuit distillation to generate quantum circuits that are short but have enough functions to produce an output similar to that of the original circuits. The distilled circuits are less sensitive to the noise and can complete calculation before the quantum coherence is broken. We created a quantum-circuit distillator by building a reinforcement learning model, and applied it to the inverse quantum Fourier transform (IQFT) and Shor’s quantum prime factorization. The obtained distilled circuit allows correct calculation on IBM-Quantum processors. By working with the distillator, we also found a general rule to generate quantum circuits approximating the general n-qubit IQFTs. The quantum-circuit distillator offers a new approach to improve performance of noisy quantum processors.