Non-perturbative gluon evolution, squeezing, correlations and chaos in jets

We study evolution of colour gluon states in isolated QCD jet at the non-perturbative stage. Fluctuations of gluons are less than those for coherent states under specific conditions. This fact suggests that there gluon squeezed states can arise. The angular and rapidity dependencies of the normalized second-order correlation function for present gluon states are studied at this stage of jet evolution. It is shown that these new gluon states can have both sub-Poissonian and super-Poissonian statistics corresponding to, respectively, antibunching and bunching of gluons by analogy with squeezed photon states. We investigate the possibility of coexisting both squeezing and chaos using Toda criterion and temporal correlator analysis. It is shown that these effects may coexist under some conditions.Comment: 18 pages, 3 figures, Reported on IPPP Workshop on Multiparticle Production in QCD Jets (University of Durham, Durham, UK, 12-15 December 2001

Nanofibrous carbon with herringbone structure as an effective catalyst of the H2S selective oxidation

Granular nanofibrous carbons (NFCs) with herringbone structure were synthesised by the decomposition of natural gas over Ni/Al2O3 catalysts, and their performance in the selective oxidation of hydrogen sulphide was studied. Samples obtained over pure Ni catalysts are the strongest mechanically and easiest to produce. However, they show low selectivity for sulphur and are unstable during operation. Boiling in nitric acid followed by annealing led to improvements in catalytic stability and a significant increase in the selectivity for sulphur in the direct oxidation of hydrogen sulphide. The addition of large amounts of water vapour to the reaction mixture dramatically improved the selectivity and stability of the NFCs. © 2010 Elsevier Ltd. All rights reserved

Investigation of Bubble Size Distributions in Oscillatory Flow at Various Flow Rates

The demand for eco-friendly technologies for industrial processes is increasing. Various factors such as labour costs, exploitation and waste management influence the production costs and hence the profit generated. The water treatment industry is one example of a well-developed sector which is facing these concerns. Microbubble techniques exhibit many benefits which make them applicable to heterogeneous processes, such as longer contact time and greater surface area giving higher mass transfer rates. The Fluidic Oscillator (FO) is a relatively new device which enhances the efficacy of microbubble generation. The FO produces smaller bubbles by applying oscillatory flow through a diffuser to generate microbubbles. This paper aims to study the influence of steady and oscillatory flow to bubble size distribution. The experimentation was carried out with a ceramic diffuser to produce microbubbles in water. A High Speed Camera was used for bubble imaging. Data on bubble distributions at various flow rates was obtained by image post-processing. It was observed that the application of the FO at selected operational conditions gave narrower bubble size distributions in a range of flow rates compared to continuous flow. The range of applications of this technology is continuously populating

Synthesis of Ni-based catalysts by hexamethylenetetramine-nitrates solution combustion method for co-production of hydrogen and nanofibrous carbon from methane

It was shown that hexamethylenetetramine (HMT)is a new effective fuel for single-step solutions combustion synthesis (SCS)of supported Ni catalysts for methane decomposition into hydrogen and nanofibrous carbon. Several generalized chemical equations reflecting different ideas about combustion of the HMT−Ni(NO 3 ) 2 −Cu(NO 3 ) 2 −Al(NO 3 ) 3 −H 2 O system have been derived. On the basis of those equations the adiabatic combustion temperature (T ad )and the amount of gaseous products (n g )have been calculated depending on the ignition temperature (T 1 ), water content (m), excess fuel coefficient (φ), and the composition of the obtained solid product. The calculations have shown that T ad , depending on m and φ, changes from hundreds to thousands of degrees Kelvin. Increase of Al 2 O 3 content in the catalyst up to 0.6 increases T ad by hundreds of degrees, and that increase of the Ni:NiO ratio up to 0.5 lowers T ad by tens of degrees. Three samples of the supported unreduced 0.97NiO/0.03Al 2 O 3 catalyst were successfully prepared with the help of the SCS method using HMT as the fuel at φ=0.7. Those samples, obtained at reaction mixture preliminary heating rates V = 1, 10, 15 K/min were characterised using XRD, TEM, and SEM, and further tested in a pure methane decomposition reaction (100 L CH4 /h/g cat , 823К, 1 bar). Nanoparticles of metal Ni were found in the SCS products, in contrast to cases when other types of fuel were used with

Efficient Compact Micro Dielectric Barrier Discharge (DBD) Plasma Reactor for Ozone Generation for Industrial Application in Liquid and Gas Phase Systems

Ozone is well known as a powerful fast reaction rate oxidant. The ozone based processes produce no by-product left as a non-reacted ozone returns back to the original oxygen molecule. Therefore an application of ozone is widely accepted as one of the main directions for a sustainable and clean technologies development. There are number of technologies require ozone to be delivered to specific points of a production network or reactors construction. Due to space constrains, high reactivity and short life time of ozone the use of ozone generators even of a bench top scale is practically limited. This requires development of mini/micro scale ozone generator which can be directly incorporated into production units. Our report presents a feasibility study of a new micro scale rector for ozone generation (MROG). Data on MROG calibration and indigo decomposition at different operation conditions are presented. At selected operation conditions with residence time of 0.25 s the process of ozone generation is not limited by reaction rate and the amount of ozone produced is a function of power applied. It was shown that the MROG is capable to produce ozone at voltage level starting from 3.5kV with ozone concentration of 5.28E-6 (mol/L) at 5kV. This is in line with data presented on numerical investigation for a MROG. It was shown that in compare to a conventional ozone generator, MROG has lower power consumption at low voltages and atmospheric pressure. The MROG construction makes it applicable for emerged and dry systems. With a robust compact design MROG can be used as incorporated unit for production lines of high complexity

Velocity field distributions due to ideal line vortices

We evaluate numerically the velocity field distributions produced by a bounded, two-dimensional fluid model consisting of a collection of parallel ideal line vortices. We sample at many spatial points inside a rigid circular boundary. We focus on ``nearest neighbor'' contributions that result from vortices that fall (randomly) very close to the spatial points where the velocity is being sampled. We confirm that these events lead to a non-Gaussian high-velocity ``tail'' on an otherwise Gaussian distribution function for the Eulerian velocity field. We also investigate the behavior of distributions that do not have equilibrium mean-field probability distributions that are uniform inside the circle, but instead correspond to both higher and lower mean-field energies than those associated with the uniform vorticity distribution. We find substantial differences between these and the uniform case.Comment: 21 pages, 9 figures. To be published in Physical Review E (http://pre.aps.org/) in May 200

Algorithms for constructing suboptimal coverings of plane figures with disks in the class of regular lattices

The problem of covering a compact planar set M with a set of congruent disks is considered. It is assumed that the centers of the circles belong to some lattice. The criterion of optimality in one case is the minimum of the number of elements of the covering, and in the other case — the minimum of the Hausdorff deviation of the union of elements of the covering from the set M. To solve the problems, transformations of parallel transfer and rotation with the center at the origin can be applied to the lattice. Statements concerning sufficient conditions for sets of circles that provide solutions to the problems are proved. Numerical algorithms based on minimizing the Hausdorff deviation between two flat compacts are proposed. Solutions of a number of examples are given for various figures of M. © 2023 The Author(s)

Joint inversion of satellite-detected tidal and magnetospheric signals constrains electrical conductivity and water content of the upper mantle and transition zone

We present a new global electrical conductivity model of Earths mantle. The model was derived by using a novel methodology, which is based on inverting satellite magnetic field measurements from different sources simultaneously. Specifically, we estimated responses of magnetospheric origin and ocean tidal magnetic signals from the most recent Swarm and CHAMP data. The challenging task of properly accounting for the ocean effect in the data was addressed through full three-dimensional solution of Maxwell's equations. We show that simultaneous inversion of magnetospheric and tidal magnetic signals results in a model with much improved resolution. Comparison with laboratory-based conductivity profiles shows that obtained models are compatible with a pyrolytic composition and a water content of 0.01 wt and 0.1 wt in the upper mantle and transition zone, respectively

Application of an Oil-Displacing Composition for Increasing Flow Rate of Low Producing High-Viscosity Oil Wells of the Usinskoye Oil Field

The results of a pilot application of a chemical composition for enhanced oil recovery developed at the IPC SB RAS are presented. The EOR-composition was tested in 2014 at the Permian-Carboniferous heavy oil deposit at the Usinskoye oil field. It is very effective for an increase in oil production rate and decrease in water cuttings of well production. In terms of the additionally produced oil, the resulting effect is up to 800 tons per well and its duration is up to 6 months. The application of technologies of low-productivity-well stimulation using the oil-displacing IKhNPRO system with controlled viscosity and alkalinity is thought to be promising. This composition is proposed for the ‘cold’ stimulation of high-viscosity oil production as an alternative to thermal methods