bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustic properties of overheated liquid with gas nuclei during temperature increasing
Authors: Galimzyanov M N , Agisheva U O 
Published: December 2019

Abstract
The characteristics of the reflection and refraction of harmonic waves at its oblique incidence on an interface between a “pure” liquid and liquid with bubbles filled with a vapor–gas mixture have been studied. For the considered problem, we have obtained the dispersion equation and carried out a numerical analysis of the effect of the perturbation frequencies in the range 102–106 s–1 on the dependence of the angle of refraction on that of incidence for three equilibrium temperatures T
0. The dependence of the critical angle of incidence on the parameters of a two-phase system and the perturbation frequencies has been studied for the same reflection.
Low-intensity pressure waves in a stratified bubbly liquid
Authors: Agisheva U O , Galimzyanov M N 
Published: December 2019

Abstract
In this work, the features of the dynamics of two-dimensional pressure waves of weak intensity in a layered bubbly liquid are investigated. A bubbly liquid, piecewise-inhomogeneous in volume content, was used as the calculated medium. The influence of the width of the bubble layer on the propagation dynamics of a pulse signal is analyzed. The possibility of the formation of pressure peaks near the boundary between the layers is shown.
Electromagnetic plasma rail accelerator for surface analysis and modification in solids
Authors: Tverdokhlebov K V , Zhukov B G , Bobashev S V , Kurakin R O , Shustrov Y A , Poniaev S A 
Published: December 2019

Abstract
In this study we investigate the possibility of using plasma rail accelerator as a dense plasma jet generator for scientific and technological purposes. It was found that plasma railgun can generate supersonic plasma jets, both pure and saturated with solid and liquid microparticles. Such jets can cause thermal and mechanical erosion of the target surface, sputtering material of the railgun channel and transferring it to the surface being treated. We studied working regimes of the plasma railgun. SEM and optical micrographs of the treated samples were obtained.
Interaction of a system of supersonic jets from a body with an incoming flow
Authors: Shevchenko A V , Yuriev A S , Poniaev S A , Pirogov S Yu , Zhitnikov T A , Rotermel A R 
Published: December 2019

Abstract
There is a need to improve the methods of control of supersonic aircraft in order to increase the efficiency and reliability of their control elements. In this work, theoretical calculations of the flow around a body with a system of supersonic jets are carried out. Using numerical methods, the possibility of control the flow around a body using a system of jets has been investigated. The numerical study was based on a model of an inviscid perfect gas described by the Navier-Stokes equations.
Colloid chemical aspects accelerated artificial petrification of wood
Authors: Danilov V E , Ayzenshtadt A M , Kilyusheva N V , Makhova T A , Belyaev A O 
Published: December 2019

Abstract
The paper describes various approaches to increasing the processing efficiency of coniferous wood with a partially soluble organo-mineral suspension for the manufacture of artificially petrified wood. The suspension was prepared by grinding the polymineral river sand from the Krasnoflotsky West deposit (Arkhangelsk region) and then mixing it with a solution of arabinogalactan. Standard samples (20x20x30 mm) of wood were immersed in the suspensions for 24 hours, after which they were taken out, dried and weighed. The processing efficiency was evaluated by increasing the density of the samples due to the filling of the wood matrix with silica (excluding arabinogalactan). The influences of the concentration of components, size characteristics and zeta-potential of the surface of silica particles on the increase in the density of samples were studied. It was confirmed that arabinogalactan promotes deeper penetration of silica particles into wood, which leads to a greater increase in density (up to 9% per treatment). It was also found that a decrease in the size of silica particles from 243 nm to 163 nm, as well as increasing the zeta potential from -30 mV to -45 mV, do not lead to a significant increase in the density of the samples.
Kinetic description of heterogeneous processes using surface tension as an information parameter
Authors: Sokolova Y V , Ayzenshtadt A M , Frolova M A , Strokova V V 
Published: December 2019

Abstract
We evaluate the possibility of using surface tension as the main information parameter for determining the order of the polycondensation reaction in the main reagent occurring in the “glyoxal-bark”. Surface tension was calculated according to the method of Owens, Wendt, Rabel and Kaelble (OWRK). In addition, the identified minus the first order of the polycondensation reaction may be due to the fact that the limiting stage occurs in the diffusion region. In this case, blocking the free reactive surface centers of the plant component of the mixture by products of the primary interaction leads to a slowdown of the process, despite an increase in the concentration of glyoxal. The unit modulus of the reaction order means that one molecule of glyoxal is involved in an elementary act of interaction of glyoxal with the structural units of the lignin macromolecule. This confirms both the working hypothesis on the mechanism of structure formation in “glyoxal-bark” system, and the possibility of using surface tension for the kinetic description of heterogeneous processes.
Modification of the GaSb(100) surface in ammonium sulfide solutions - morphology and stoichiometry
Authors: Dementev P A , Lebedev M V , Lvova T V 
Published: December 2019

Abstract
The changes in the stoichiometry and morphology of the GaSb(100) surface in the process of sulfide passivation with aqueous and alcoholic ammonium sulfide solutions were studied by AFM and XPS. It was found that after sulfide treatment the Ga/Sb ratio can vary in the range from 0.13 to 3, while the surface roughness can be changed from 1.1 to 5.5, depending on the concentration of the (NH4)2S solution, solvent and passivation time.
Calculation of self-consistent electrophysical parameters of semiconductor gas sensors based on samarium sulfide for semiconductor Fourier spectroscopy of volatile hydrocarbons contained in atmospheric air
Authors: Kazakov S A , Grevtsev M A , Khavrov G D , Solov’ev S M , Sharenkova N V , Kazanin M M , Kaminskii V V 
Published: December 2019

Abstract
The developed method of semiconductor gas Fourier spectroscopy is based on the relationship of the obtained calibration characteristics of the concentration sensors for volatile hydrocarbons contained in atmospheric air (in our case, it is methane and propane), with electrophysical parameters of the gas sensitive layers. The study used gas sensors based on samarium sulfide with reproducible and stable calibration characteristics. The working layers of hydrocarbon concentration sensors were obtained by two different methods: the explosive spraying method and the sol-gel coating technology. In this paper we present a system of equations that includes the main electrophysical characteristics of a gas-sensitive film which is solved by numerical methods. These equations reflect a unique relationship between the Debye screening length (Ld
), film thickness (d), Fermi level (EF
), concentration of impurity levels (Nd
), dielectric constant of the medium (ε), crystal lattice constant (a), and mobility of the main charge carriers (μ) with the observed data on the change in the conductivity of thin films of samarium sulfide in the processes of adsorption of methane and propane molecules on their surface. In the present work, we obtained the first calculated data of such parameters for the current prototype images of gas sensors of methane and propane.
Theoretical methods for definition of the emission area of multi-tip cathodes and their experimental validation
Authors: Popov E O , Kolosko A G , Filippov S V , Poniaev S A 
Published: December 2019

Abstract
The processing of the current-voltage characteristics (IVC) taken from multi-tip field emitters (LAFEs) requires a streamlined and objective processing method for obtaining the main emission parameters. This paper considers different approaches for determining the effective emission surface. Methods for determining the area are applied to the analysis of experimental IVCs for single-walled (SW) and multi-walled (MW) LAFEs. The dependence of the effective emission area on the applied voltage was confirmed.
Temperature regimes of drained and natural peatlands in arid and water-logged years
Authors: Kiselev M V , Voropay N N , Dyukarev E A , Preis Yu I 
Published: December 2019

Abstract
The results of a study of temperature regimes of oligotrophic bog ecosystems in the south taiga zone of Western Siberia in 2011-2018 are presented. Soil temperature regimes are studied using an atmospheric-soil measuring complex at several depths from the surface to 320 cm. Waterlogged (excessive moisture) and arid years are determined by calculating the aridity index of Ped (S). The years with most severe hydrothermal conditions over the past 10 years have been found to be 2012 and 2018. In 2012, a drought is observed from April to July, with extreme aridity in June (S = 4.07), and a severe drought in July (S = 3.42). It has been found that the native treed bog in a wet year warms up much more than in a dry year. On average, the temperature values are higher by 1.5°C for all depths. On average, the drained bog is colder than the natural one at depths up to 80 cm by 4.0°C, and at depths of 120 to 240 cm by 2.5°C. The maximum temperature differences of the native bog during the warm period of a waterlogged (excessive moisture) year are 8.0°C (at a depth of 60 cm) and, at depths from 80 to 240 cm they are reduced from 5.0 to 2.5°C. The maximum differences of the native bog in the waterlogged (excessive moisture) 2018 and dry 2012 in the warm period at a depth of 60 cm are 8.0-9.0°C, and from 80 to 240 cm they are reduced from 6.0 to 1.5°C.
Modeling of near-surface flows over an aeolian relief
Authors: Malinovskaya E A , Chkhetiani O G 
Published: December 2019

Abstract
As a result of interaction of an air flow with the elements of an aeolian relief, the character of the flow changes. It affects both the conditions of dust blowing from the surface and the surface shape itself. A model is developed for the formation of the windward slope under the influence of wind. It makes it possible to estimate the dynamic speed when moving up the windward slope on the basis of data on height and movement of the dunes. The coefficient of linear change in the dynamic velocity and its decrease with increasing structure are obtained. This property is probably due to a change in the nature of the flow and circulation at the surface. To study such problems, dome methods are applied to simulate the air flow near a complex 3D surface using the open OpenFOAM package with a 4-level spatial grid. A technology is also proposed for converting the digital terrain data into a format understandable to mathematical packages for modelling of air flow around a 3D object. Based on the simulation results, the coefficient of linear change in the dynamic velocity for aeolian structures with a height of about 100 m has been calculated, which generally corresponds to values obtained from theoretical estimates and real data on changes in height and movement of dunes.
Calculating scheme of ground freezing depth on the basis of data on seasonal snowfall deposition, snow cower accumulation and temperature variation
Authors: Frolov D 
Published: December 2019

Abstract
Soil thermal regime remains today an insufficiently studied field of environmental computing science. For the determination of the influence of air-temperature and snow cover thickness absolute values and dynamics on the ground freezing depth, and the development of root systems of trees and plants, a calculating scheme on the basis of data on seasonal snowfall deposition, snow cover accumulation, and temperature variation is considered. The calculating scheme is based on a three-layer media heat conduction problem (snow cover, frozen and thawed ground) with phase transition on the boundary between frozen and unfrozen grounds. The heat balance equation includes phase transition energy, inflow of heat from the unfrozen ground and outflow to the frozen ground, snow cover and the atmosphere. The heat flux is calculated on the basis of the Fourier law as the product of heat conductivity and temperature gradient. It is supposed that the temperature changes in each of the media linearly. An assumption is also made that snow cover consists of different layers deposited by different snowfalls and having different structure, density, and heat conductivity depending on its density. The density and heat conductivity of each layer and the whole thickness of snow cover are determined, a regional stratigraphic column for snow cover is compiled, and the ground freezing intensity and freezing depth are calculated. A comparison of the calculated and observed values of ground freezing depth for Narayan-Mar is performed, and a correlation of 0.76-0.77 is obtained.
An experimental study of atmospheric turbulence characteristics in an urban canyon
Authors: Pashkin A D , Repina I A , Stepanenko V M , Bogomolov V Y , Smirnov S V , Telminov A E 
Published: December 2019

Abstract
This article presents the first results of an experimental study of turbulent heat exchange between a surface surrounded by buildings and the atmospheric boundary layer. Heat and momentum fluxes are measured at three levels in the first part of the experiment and three points in the second part of the experiment by an eddy covariance (EC) technique. The presence of wind-shear effects is supported in our measurements by the fact that the momentum flux increases with height from the surface. The sensible heat flux increases with height in the daytime. The distributions of the dimensionless proportionality coefficients between the third and second moments thus obtained indicate the presence of coherent structures in the surface layer.
Inverse problems for the study of climatic and ecological processes under anthropogenic influences
Authors: Penenko V V , Tsvetova E A 
Published: December 2019

Abstract
This paper presents a description of algorithms for solving direct and inverse climatic and environmental problems based on a variational principle with weak constraints. The initial first-order system is supplemented by a system of equations in variations. It provides a calculation of all necessary components of the modeling system by combining the model and observation data and including first- and second-order functionals of sensitivity to variations in the model parameters, input data, and observation results.
Elements of software package for “cloud” analysis of the environment and climate change
Authors: Okladnikov I G , Gordov E P , Ryazanova A A , Titov A G 
Published: December 2019

Abstract
The architecture and new basic components of an information and computing software package are presented. It is based on a software framework dedicated to carrying out scientific research related to statistical processing and analysis of spatial geophysical data archives obtained from observations and modelling. To create the package, experience in the development of some information-computational web GISs for processing of large amounts of spatial data has been used. The basic components of this complex are represented by several procedures for searching, sampling, and processing of spatial data arrays, as well as by elements of a graphical user interface. The flexible structure of the computing unit of this software complex provides a possibility of operative expansion of its functionality by using additional procedures for mathematical and statistical analysis, processing, and graphical representation of the results in the form of graphs, diagrams, and plots on maps of the territory of interest.
Spatial distribution of extreme wind speeds over Sakhalin Island based on observations and high-resolution modelling data
Authors: Platonov Vladimir , Kislov Alexander 
Published: December 2019

Abstract
An analysis of extreme wind speeds over Sakhalin region shows that a set of wind speed extremes obtained from observations is a mixture of two different subsets, each of them neatly described by a Weibull distribution. The empirical tail of the pdf diverges from a linearized Weibull model, indicating that another model could fit the most extreme wind speed data better. Each of these subsets is characterized by parameters k and A, regarded as coefficient and free terms of the linear Weibull model, these samples are labelled BSs and Ds. The Ds are responsible for the strongest extremes. Mesoscale modelling is used to investigate a possibility of the models to reproduce these statistical features. A detailed hydrodynamic simulation of major meteorological parameters (1985 – 2014) has been performed for the Sea of Okhotsk and Sakhalin Island with horizontal resolutions of ~13.2, ~6.6, and ~2.2 km by using a regional climate model, COSMO-CLM. This dataset is utilized for an investigation of the statistical structure of extreme wind speeds. First, it is shown that a model with a detailed spatial resolution is able to reproduce the statistical structure in general, and a special mechanism is responsible for the generation of the largest of wind extremes. However, a model with a resolution of ~13,2 km could not reproduce some essential parts of the wind speed maximum’ statistical properties, underestimating the parameters k and A of Ds Weibull distribution significantly. This gap could be covered by using a higher resolution, as well as by areal estimation techniques and many others.
Organic matter of floodplain lakes in the middle courses of the Ob River during the winter low-water season and the spring flood
Authors: Kolesnichenko L G , Lutova E S , Borilo L P , Vorobiev S N , Prokushkin A S , Kolesnichenko Iu Ya , Raudina T V , Rozhkova-Timina I O , Yasnova A S , Pokrovsky O S 
Published: December 2019

AbstractThe features of the organic matter composition of the lake waters of the Ob River floodplain in the winter low-water and the spring flood periods were investigated. It is shown that the organic matter of the studied lakes is significantly different from the organic matter of the Ob water. In the winter low-water season, floodplain lakes accumulate a large amount of organic aromatic allochotic substances, and in the flood there are changes in the composition of organic matter
Evidence That Implementation Intentions Enhance Cognitive Training and Reduce Alcohol Consumption in Heavy Drinkers: A Randomized Trial
Authors: Mcgrath Elly , Armitage Chris J , Mckie Shane , Millar Tim , Ab-Ghani Asmuni , Elliott Rebecaa 
Published: December 2019

AbstractBackgroundCurrent training tasks to improve the cognitive deficits thought to be involved in sustained heavy drinking need further investigation to optimize their effectiveness.PurposeThe present study investigated whether combining implementation intention provision with a cognitive training task had a measurable effect on alcohol consumption in heavy drinkers and explored the neural mechanisms underpinning any reductions in subsequent alcohol consumption.MethodsThirty-two heavy-drinking participants completed approach-avoidance and visual probe training tasks preintervention and postintervention during functional Magnetic Resonance Imaging. Participants in the intervention group were randomized to form implementation intentions and participants in the control condition read a goal intention. Alcohol consumption was recorded preintervention and at 1 month follow-up.ResultsCompared to the control group, implementation intention provision significantly improved performance on alcohol-avoidance tasks postintervention, t(30) = −2.315, p = .028, d = .85, and reduced alcohol consumption by 6.9 units/week (1 unit = 10 mL or 8 g ethanol), F(1,30) = 4.263, p = .048 (d = .74), at follow-up. However, the analysis of functional Magnetic Resonance Imaging data revealed no significant differences between groups.ConclusionsThese findings show for the first time that implementation intentions targeting cognitive processes can significantly reduce alcohol consumption among heavy drinkers. However, there was no evidence that the effects were mediated by changes in neural activity. Further work is required to explore the neural mechanisms underpinning the operation of implementation intentions.Trial RegistrationThis trial was registered (ISRCTN:35503634) and is available at https://www.isrctn.com/ISRCTN35503634.
Adaptive Treatment Strategies With Survival Outcomes: An Application to the Treatment of Type 2 Diabetes Using a Large Observational Database
Authors: Simoneau Gabrielle , Moodie Erica E M , Azoulay Laurent , Platt Robert W 
Published: December 2019

Abstract
Sequences of treatments that adapt to a patient’s changing condition over time are often needed for the management of chronic diseases. An adaptive treatment strategy (ATS) consists of personalized treatment rules to be applied through the course of a disease that input the patient’s characteristics at the time of decision-making and output a recommended treatment. An optimal ATS is the sequence of tailored treatments that yields the best clinical outcome for patients sharing similar characteristics. Methods for estimating optimal adaptive treatment strategies, which must disentangle short- and long-term treatment effects, can be theoretically involved and hard to explain to clinicians, especially when the outcome to be optimized is a survival time subject to right-censoring. In this paper, we describe dynamic weighted survival modeling, a method for estimating an optimal ATS with survival outcomes. Using data from the Clinical Practice Research Datalink, a large primary-care database, we illustrate how it can answer an important clinical question about the treatment of type 2 diabetes. We identify an ATS pertaining to which drug add-ons to recommend when metformin in monotherapy does not achieve the therapeutic goals.