Forecasting of phase behavior and PVT-properties of natural gas is one of the major tasks during the developing and operation of gas and gas condensate fields. Each stage – from an exploration to ...transportation and storage of gas is followed by continuous changes of thermobaric conditions. This causes changes of thermodynamic properties of gas, one of which is compressibility factor. The comparative study of the existing theoretical methods of compressibility factor determination is given in the presented work: based on the equation of state and empirical correlations. Besides, the alternative approach based on molecular dynamics simulations with the Lennard-Jones potential is offered. The analysis of the received results is carried out on the basis of 165 experimental data for 5 various mixtures of natural gas covering temperatures of 310.9 – 344.4 K and pressure range of 7.074 - 48.443 MPa. The statistical analysis shows that the molecular dynamics method shows the minimum error and is suitable for determination of z-factor of mixtures with methane content more than 90%. For mixtures with the high content of carbon dioxide the Peng-Robinson equation of state with shift-parameter shows the minimum error.
—
The characteristics of neutron scintillation detectors built on monolithic and heterogeneous scintillators containing
6
Li were studied. The detectors were tested on a thermal neutron beam and on a ...stand with a source of γ-quanta
60
Co. To process the signals received from the detector with a monolithic scintillator, three different γ-radiation discrimination algorithms were used: registration of pulses at a constant threshold and selection according to the pulse shape using two digital signal separation methods: charge integration and pulse duration measurement. For a homogeneous scintillator, pulse shape selection methods work approximately the same when separating thermal neutrons and γ-quanta and are significantly inferior to the method of registration at a constant threshold. In this case, the quality of the
n
/γ separation is worse than the result obtained with a heterogeneous scintillator when recording at a constant threshold. The purpose of the work is to compare the results of using digital methods for discrimination of gamma-quanta with the results obtained using heterogeneous scintillators.
Straw tubes with resistive cathode and cathode readout were successfully manufactured and tested. The straw tubes were manufactured by ultrasonic welding technique. The resistive cathode electrode ...was made of diamond like carbon (DLC). The possibility of cathode signal readout from external strip electrodes was successfully demonstrated. The event coordinate along the straw can be accurately determined by applying center of gravity method to the individual strip signals.
The kinetics of internal mass transfer in the course of evaporation of liquids in elastic capillary systems in which the transverse dimensions of the pores can both decrease and increase on exposure ...to intense thermal effect is investigated. Structural transformations in a material arise as a result of its dehydration. It is assumed that the channel radius changes simultaneously over the entire length, synchronously with the interface motion. Three schemes are possible in principle: a uniform change during the process, a faster change in the initial stage, and, conversely, a faster change in the closing stage. The time-limited additional thermal effect during the period that makes the main contribution to the overall duration of the process is capable of substantially enhancing mass transfer with minimum energy consumption.
Heterogeneous nucleation in extended states of liquid argon with a solid particle is studied with molecular dynamics methods. The rupture strength of cavitation in the liquid is determined as a ...function of the energy of interaction between molecules of liquid and those of solid inclusion. The influence of solid particle sizes on the nucleation process is explored.
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A Monte Carlo model of the thermal-neutron scintillation detector based on NE 912 lithium glass has been created and verified. The simulation was validated by comparing its result to experimental ...data from a prototype detector exposed to thermal-neutron and γ-ray beams. The light yield in the scintillator for a captured thermal neutron, the quenching factor, and the decay times of the scintillator were determined. The accuracy in reproducing the pulse shapes obtained in the experiment is sufficient to allow analysis of experimental data and estimation of the efficiency of
n
/γ discrimination techniques. Based on the simulation, it is possible to develop detector models with a low γ-ray sensitivity using heterogeneous composite scintillators with various geometries.
Data analysis of an experiment in which photon splitting in atomic fields was observed is presented. The experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M ...collider. In the energy region of 120-450 MeV, statistics of 1.6x10(9) photons incident on the BGO target was collected. About 400 candidate photon-splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the calculated exact atomic-field cross section. The predictions obtained in the Born approximation differ significantly from the experimental results.
A
bstract
We present the study of the decay
J/ψ
→
ρπ
. The results are based on of 5.2 million
J/ψ
events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured ...to be
B
(
J/ψ
→
ρπ
) = (2
.
072 ± 0
.
017 ± 0
.
062) ∙ 10
−
2
and
B
(
J/ψ
→
π
+
π
−
π
0
) = (1
.
878 ± 0
.
013 ± 0
.
051) ∙ 10
−
2
, where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.
Drell-Yan lepton pairs produced in the process pp¯→ℓ+ℓ−+X through an intermediate γ*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the ...electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin2θefflept using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9–10 fb−1 of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin2θefflept=0.23148±0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin2θW, or equivalently the W-boson mass MW, using the zfitter software package yields sin2θW=0.22324±0.00033 or equivalently, MW=80.367±0.017 GeV/c2.
Electron affinity of oganesson Kaygorodov, M. Y.; Skripnikov, L. V.; Tupitsyn, I. I. ...
Physical review. A,
07/2021, Volume:
104, Issue:
1
Journal Article
PDF
