Sulfur compounds are found in crude benzene from coke production. One of these compounds is thiophene. Extractive distillation (ED) with dimethylformamide as a separating agent can be used to remove ...it from crude benzene. The relative volatility in the benzene–thiophene binary system increases in the presence of dimethylformamide from 1.13 to 1.46–2.18. The purpose of this work is to study the possibility of using a scheme that includes a complex extractive column (EC) with side withdrawal in the vapor phase. New schemes of ED have been synthesized and mathematical modeling and their optimization have been carried out. It is shown that the proposed scheme of ED provides a decrease in energy consumption by 29.5% and the amount of circulating extractive agent (E) by 47.8%. At the same time, the requirements for the quality of benzene purification and its losses with the thiophene fraction are met.
Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of ...micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nucleation sites per unit mass active in the immersion freezing mode at −12 °C than montmorillonite, the nucleation properties of which are often used to represent those of mineral dusts in modelling studies. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.
First results on
-dependence measurements in inclusive
meson production in
interactions (
, Al, Cu, Sn, and W) are presented at
GeV/
c
. The ratios of the differential cross sections of four of these ...nuclei to the differential cross section on aluminum were measured and the dependence of these cross sections on the atomic of the nucleus was studied. The measurements were carried out in the kinematic region of the Feynman variable
and transverse momentum
GeV/
c
.
mesons were detected in the decay mode
at the SPASCHARM experimental setup using negative charged beams at beamline 14 of the U-70 accelerator complex.
The steam oxygen-free gasification allows deep processing of coal and obtaining gas with high contents of H2 and CO. The design of dual fluidized bed gasifiers (DFB) is considered promising. There ...are insufficient experimental data on the steam gasification process in DFB for more accurate mathematical modeling. The paper presents the experimental results in dynamics of the quasi-stationary and non-stationary gasification of two types of coals in a laboratory gasifier. It has been established that when using superheated steam for preliminary and main gasification process, it is possible to obtain a gas with a total content of H2 and CO of more than 75% vol, maximum cold gas efficiency 87%. The conditions for the expedient use of two chambers for gasification of coals of different degrees of metamorphism are identified. The gasification regimes that will increase H2 and CO formation in DFB are determined. This research substantiate the necessarily to use only steam in DFB for improving the synthesis gas quality.
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•Coal gasification in steam allows to obtain the gas with high total content of H2 and CO.•The degree of coal metamorphism affects the gasification process significantly.•Increasing of the temperature and the flow rate of steam allows to H2 and CO growth.•It is more preferable to use highly-metamorphosed coals at higher thermal stresses.•Pre-activated using gasifying agents is necessary for low-metamorphosed coals.
The STAR Barrel Electromagnetic Calorimeter Beddo, M.; Bielick, E.; Fornek, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2003, Letnik:
499, Številka:
2
Journal Article
Recenzirano
Details concerning the design, fabrication and performance of the STAR Barrel Electromagnetic Calorimeter are presented.
The new SPASCHARM experiment for systematic studies of polarization phenomena in strong interactions is under construction now at IHEP, Protvino. The technical beam runs for the experiment first ...stage are planned for the Fall 2016 and Spring 2017. At this stage, the polarization measurements will be carried out with unpolarized hadronic beams of various compositions (π±, K±, p, antiprotons), using the polarized target. The universal large acceptance experimental set-up is capable detecting and identification most charged and neutral particles and reconstructing a large number of resonances produced in beam interactions at polarized proton target, and later on at the second stage, in collisions of polarized proton and antiproton beams with fixed targets of various materials. The large acceptance and wide data acquisition bandwidth would provide the capabilities for simultaneous data accumulation for a number of physics analyses from the measurements of single-spin asymmetries in inclusive and exclusive reactions to reconstructions of final state hyperon polarizations and spin density matrix elements for vector mesons in a wide range of kinematic variables (pT, xF).
A new experiment SPASCHARM for systematic study of polarization phenomena in inclusive and exclusive hadronic reactions is currently under commissioning at IHEP. The universal experimental setup will ...detect dozens of various resonances and stable particles produced in collisions of unpolarized beams with the polarized target, and at the next stage, using polarized beams. At the first stage with polarized target, the final states composed of light quarks (u, d, s) will be reconstructed. Hyperon polarization and spin density matrix elements of the vector mesons will be measured along with the single-spin asymmetries. The 2π-acceptance in azimuth, which is extremely useful for reduction of systematic errors in measurements of spin observables, will be implemented in the experiment. The solid angle acceptance of the setup, Δθ≈250 mrad vertically and 350 mrad horizontally in the beam fragmentation region, covers a wide range of kinematic variables pT and xF. This provides the opportunity for separating dependences on these two variables which is usually not possible in the setups with a small solid angle acceptance. Unlike some previous polarization experiments, the SPASCHARM will be able to simultaneously accumulate and record data on the both, charged and neutral particle production.
The SPASCHARM experiment is aimed at a systematic study of the nucleon spin structure and the spin dependence of the strong interaction of antimatter and matter with matter at energies up to 45 GeV. ...As part of the first stage of the experiment, the study of the spin properties of hadrons will take place in a beam of negatively charged hadrons on existing beamline 14 at the operating SPASCHARM setup at the U70 facility. At the second stage, the production of polarized beams of protons and antiprotons is envisaged in beamline 24A of the U-70 accelerator facility. A polarized antiproton beam will certainly become a unique beam in the world. It is planned to measure single-spin asymmetries in dozens of reactions, both on hydrogen and on various nuclei. At the SPASCHARM facility, it is also possible to measure the transverse polarization of hyperons and elements of the spin density matrix of vector mesons. The spin structure of the nucleon will be investigated in the study of quarkonium production to determine the contribution of gluons to the proton spin. The presence of two types of polarized beams and eight types of nonpolarized beams (π
±
,
K
±
,
p
,
,
d
,
C
), in combination with a polarized target, expands the range of studies of polarization phenomena and enhances the uniqueness of the project.
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