bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orbital eccentricities as indicators of stellar populations
Authors: Cubarsi R. , Stojanović M. , Ninković S. 
Published: June 2021

Context.In previous work, we showed how the planar and vertical eccentricities of disc stars,eande′, could be used as indicators of the stars’ kinematic populations. For a local stellar sample drawn from theGaiaDR2 catalogue, these populations were represented geometrically in the eccentricity diagram,e′2vs.e2, approximately separated by straight lines.Aims.In the current work, we propose a new relationship between the star’s perpendicular velocity and its vertical eccentricity, allowing for a reevaluation of the critical vertical eccentricity and maximum height,zmax, specific to each population component.Methods.We approximated the local potential function to be consistent with the actual shape of the curve that relates the maximum vertical speed of a star and its maximum height. The curve corresponds to a non-linear restoring vertical force, where the stiffness decreases with an increase in the maximum height. The constants involved in this fitting, together with the population velocity dispersions, determine the specific region for each population in the eccentricity diagram.Results.The new classification determines 88% of the sample is made up of thin disc stars and 9% of thick disc stars, whereby 3% of the stars have been relabelled, by providing thinner thin and thick discs. Nested thin disc subsamples allow us to estimate Strömberg’s asymmetric drift equation, leading to a heliocentric velocity of the circular orbit ofVc ≈ −12.9 km s−1, an absolute rotation velocity of Θc ≈ 227 km s−1, and a rotation component of the Galactocentric velocity of the Sun at Θ⊙ ≈ 240 km s−1.Conclusions.The thin disc stars of our local sample are characterised based on values 0 ≤ e ≤ 0.32, 0 ≤ e′ ≤ 0.09, andzmax = 0.7 kpc. Disc stars satisfy 0 ≤ e ≤ 0.44, 0 ≤ e′ ≤ 0.18,zmax = 1.5 kpc. The maximum vertical peculiar velocity for disc stars is found to bew0 = 115 km s−1. The assumed potential provides a stellar density of the disc vanishing atz0 = 1.8 kpc. The approximate behaviour in the local disc is that a small decrease in the stiffness is associated with a relative decrease in the limiting velocity, which produces a thinner disc and a loss of stars in the local cylinder, both in a similar proportion to the limiting velocity.
Multi-wavelength VLTI study of the puffed-up inner rim of a circumbinary disc
Authors: Corporaal A. , Kluska J. , Van Winckel H. , Bollen D. , Kamath D. , Min M. 
Published: June 2021

Context. The presence of stable, compact circumbinary discs of gas and dust around post-asymptotic giant branch (post-AGB) binary systems has been well established. We focus on one such system, IRAS 08544−4431.
Aims. We present an interferometric multi-wavelength analysis of the circumstellar environment of IRAS 08544−4431. The aim is to constrain different contributions to the total flux in the H-, K-, L-, and N-bands in the radial direction.
Methods. The data obtained with the three current instruments on the Very Large Telescope Interferometer (VLTI), VLTI/PIONIER, VLTI/GRAVITY, and VLTI/MATISSE, range from the near-infrared, where the post-AGB star dominates, to the mid-infrared, where the disc dominates. We fitted the following two geometric models to the visibility data to reproduce the circumbinary disc: a ring with a Gaussian width and a flat disc model with a temperature gradient. The flux contributions from the disc, the primary star (modelled as a point source), and an over-resolved component were recovered along with the radial size of the emission, the temperature of the disc as a function of radius, and the spectral dependencies of the different components.
Results. The trends of all visibility data were well reproduced with the geometric models. The near-infrared data were best fitted with a Gaussian ring model, while the mid-infrared data favoured a temperature gradient model. This implies that a vertical structure is present at the disc inner rim, which we attribute to a rounded puffed-up inner rim. The N-to-K size ratio is 2.8, referring to a continuous flat source, analogues to young stellar objects.
Conclusions. By combining optical interferometric instruments operating at different wavelengths, we can resolve the complex structure of circumstellar discs and study the wavelength-dependent opacity profile. A detailed radial, vertical, and azimuthal structural analysis awaits a radiative transfer treatment in 3D to capture all non-radial complexity.
Revision Facelift and Neck Lift
Authors: Dibbs Rami P. , Chamata Edward , Ferry Andrew M. , Friedman Jeffrey D. 
Published: June 2021

AbstractFacial rejuvenation procedures have become more commonly performed due to an increasing elderly population and greater general public acceptance. As a result, patients are now increasingly undergoing secondary and tertiary rhytidectomies to treat natural aging and/or to correct complications from prior procedures. Revision face and neck lifts are more complex by nature of the procedure and require a comprehensive preoperative assessment for enhanced outcomes. In this review, we discuss the preoperative evaluation, surgical challenges encountered, primary face and neck lift deformities, and their surgical management for patients undergoing secondary face and neck lifts.
Revision Breast Augmentation
Authors: Denney Brad D. , Cohn Alvin B. , Bosworth Jeremy W. , Kumbla Pallavi A. 
Published: June 2021

AbstractBreast augmentation is consistently one of the most commonly performed aesthetic operations every year. Unfortunately, revision rates following primary augmentation remain as high as 36%. There are several causes for revision breast augmentation; however, the most common and challenging of these include capsular contracture, implant malposition, and ptosis of the aging breast following augmentation. Successful management of these problems requires knowledge on how to best treat the implant and capsule with the corresponding soft tissue simultaneously. While surgical management is important, understanding the pathological causes of these entities during the primary operation can reduce the need for revision. This article utilizes the most up-to-date literature to review the appropriate clinical evaluation and surgical management of these complex cases.
Optimization of process parameters for thermal shock resistance and thermal barrier effects of 8YSZ thermal barrier coatings through orthogonal test
Authors: Wu Shuo , Zhao Yuantao , Li Wenge , Liu Weilai , Wu Yanpeng , Liu Fukang 
Published: June 2021

The thermal shock resistance and the thermal barrier effects are the key indices for thermal barrier coating (TBC) performances. The performance optimization of 7∼8 wt. % Y2O3 stabilized ZrO2 (7∼8YSZ) TBCs is a research focus at present. In this work, an orthogonal test was employed to study the relationship between parameters and performances and match process parameters for TBCs preparation. The scanning electron microscope was employed to analyze the microstructures of 8YSZ TBCs. The thermal shock resistance test and thermal barrier effect test were conducted to judge the performances of 8YSZ TBCs. It was found that the process factor had the greatest influences on porosity and elastic modulus was spraying distance and the factor had the greatest influence on bond strength was spraying power. The selected parameters were a spraying distance of 90 mm, an argon flow of 32 L/min, a hydrogen flow of 8 L/min, an electric current of 550 A, a spraying power of 35 kW, a feeding rate of 45 g/min, and a substrate preheating temperature of 373 K. The thermal shock life was ∼100 times under 1173∼298 K, and the thermal barrier temperature of optimized 8YSZ TBCs with thicknesses of 250 and 300 µm was ∼90 and ∼130 K under 1473 K, respectively. Through a comparative study, both thermal shock resistance and thermal barrier effects of 8YSZ TBCs were improved after process parameters’ optimization conducted by this method.
Improved pulsed field magnetisation in MgB2 trapped-field magnets
Authors: Moseley D A , Matthews G A B , Zhou D , Cientanni V , Tsui Y , Ainslie M D , Speller S , Durrell J H 
Published: June 2021

Abstract
Bulk superconductors can act as trapped-field magnets with the potential to be used for many applications such as portable medical magnet systems and rotating machines. Maximising the trapped field, particularly for practical magnetisation techniques such as pulsed field magnetisation (PFM), still remains a challenge. PFM is a dynamic process in which the magnetic field is driven into a superconducting bulk over milliseconds. This flux motion causes heating and a complex interplay between the magnetic and thermal properties. In this work, the local flux density during PFM in a MgB2 bulk superconductor has been studied. We find that improving the cooling architecture increases the flux trapping capabilities and alters the flux motion during PFM. These improvements lead to the largest trapped field (0.95 T) for a single MgB2 bulk sample magnetised by a solenoidal pulsed field magnet. The findings illustrate the fundamental role bulk cooling plays during PFM.
Cosmological gravity on all scales. Part II. Model independent modified gravity N-body simulations
Authors: Srinivasan Sankarshana , Thomas Daniel B. , Pace Francesco , Battye Richard 
Published: June 2021

Abstract
Model-independent constraints on modified gravity models hitherto exist mainly on linear scales [1]. A recently developed formalism presented a consistent parameterisation that is valid on all scales [2]. Using this approach, we perform model-independent modified gravity N-body simulations on all cosmological scales with a time-dependent μ. We present convergence tests of our simulations, and we examine how well existing fitting functions reproduce the non-linear matter power spectrum of the simulations. We find that although there is a significant variation in the accuracy of all of the fitting functions over the parameter space of our simulations, the ReACT [3] framework delivers the most consistent performance for the matter power spectrum. We comment on how this might be improved to the level required for future surveys such as Euclid and the Vera Rubin Telescope (LSST). We also show how to compute weak-lensing observables consistently from the simulated matter power spectra in our approach, and show that ReACT also performs best when fitting the weak-lensing observables. This paves the way for a full model-independent test of modified gravity using all of the data from such upcoming surveys.
Define of effective process working combine mixing system
Authors: Yu Suslov D , Temnikov D O 
Published: June 2021

Abstract
Biogas technologies as an alternative energy source are widespread in the EU countries. But on the territory of the Russian Federation, this process is poorly understood. Since the potential from the use of biogas technologies is significant, a combined substrate mixing system has been proposed. Computer simulation of various mixing parameters was carried out and optimal modes were determined. As a result of a series of computational experiments, it was found that the developed mixing system allows the mixing time to be doubled in comparison with the traditional mechanical mixing system in a cylindrical bioreactor. At the same time, the uniformity of mixing is 16% higher. The volume of stagnant zones is 2.72 times lower. The obtained results give grounds to assume about a possible improvement of the habitat for microorganisms and, as a consequence, an increase in the rate of their distribution in the bi-oreactor, which in turn increases the rate of fermentation and the volume of biogas produced.
Regularities of distribution of the relative air humidity in the volume textile fiber material in the production of yarn
Authors: Koshev A N , Eremkin A I , Averkin A G , Rodionov Y V 
Published: June 2021

Abstract
Methods for calculating the moistening of textile fibers in the process of yarn production when processing with conditioned air with certain technological parameters based on mathematical modeling and numerical methods are presented. There are appropriate mathematical models, adequately describing the process of distribution of the relative air humidity in the porous medium under consideration. A mathematical model of the process of moistening porous of a textile material in the form of the Cauchy problem for a second-order differential equation for the purpose of numerical modeling of the change in the relative humidity of conditioned air in the volume of a compactly formed semi-finished product of textile production. The classical instability of the problem is shown, methods of its solution are considered, the problem is numerically solved for various options of technological conditions for organizing the humidification process. Numerical calculations have shown that the relative humidity of the air flow decreases monotonically with distance from the surface to a certain limiting value. At the same time, an increase in the specific surface area of a capillary-porous medium leads to a more intense drop in the relative humidity of the conditioned air in a moving air stream. The results of numerical studies show that with an increase in the flow rate of conditioned air, the depth of penetration of moisture into the volume of a porous medium increases, i.e. more moisture settles on the last layers of the volume. Consequently, to optimize the process, one should choose an air flow rate that provides a sufficient intensity of material moistening with deep penetration of moisture into the volume of a porous medium. Mathematical models of changes in the air flow rate in the volume of a porous medium according to linear and exonential laws are presented. It is shown that taking into account the drop in velocity according to the exponential law allows one to obtain good agreement between the calculated and experimental data. Physical and mathematical modeling of the non-stationary process of moisture distribution in a textile material during its humidification with conditioned air for the case of diffusion kinetics of the humidification reaction in the form of a boundary value problem for the diffusion equation has been carried out. On the basis of physical concepts of the processes occurring at the boundary of a porous medium and in its volume, modeling equations and boundary conditions for the problem of calculating the unsteady distribution of moisture in a porous medium are formulated.
Prospects for the use of waste cement industry in the production of clinker-free concrete
Authors: Sh Salamanova M , Yu Murtazayev S-A , Kh Alaskhanov A , Saydumov M S 
Published: June 2021

Abstract
The production of Portland cement clinker is accompanied by huge dust release and the accumulation of huge amounts of aspiration and clinker dust in the dust collection system. The rational use of this high-quality corrected fine-dispersed resource is an urgent task not only in technological, but also in ecological terms. Aspiration dust cannot be returned to the technological cycle. It is taken out of the cement plant, disrupting the ecological situation of valuable agricultural land and mountainous landscape. Taking into account the fact that it can be used in its natural form, without an additional mechanical intervention, this will expand the material and raw material base for the production of alkaline cements. This paper presents the results of studies of the particle size distribution of particles in samples of dispersed material and the determination of the shape and size of cement dust particles. The reactivity of the investigated powders of technogenic nature has been proved. These characteristics of cement dust electrostatic indicate feasibility of these powders dispersed as component binders ligaments alkaline activation.
On the assessment of the stress condition of a T-shaped frame supporting structure during the experimental process
Authors: Durakov S V , Bukovtsova A I , Kozhukhova N I 
Published: June 2021

Abstract
Due to the specifics of the distribution of forces in a two-span frame, it is necessary to increase the cross-sections of the central part of the girder, which negatively affects the consumption of steel for the production of the frame. To reduce the influence of the specifics of the distribution of internal forces on the weight indicators in the girder of a two-span frame, it is necessary to use innovative constructive ways of distributing forces in the girder of the frame, which affect the reduction of material consumption. Such structures include the two-span frame with T-shaped supports proposed in this article, the calculation method of which is based on the idea of combining functions. Since the design is a newly proposed one, it is necessary to identify its stress state. Experimental studies are one of the ways to identify the stress state. The experimental research methodology is presented in the article. This article proposes an assessment of the stress state of a new structural form of a frame with T-shaped support. The development of the section method and the finite difference method makes it possible to evaluate the stress state of the frame from the deformations measured in the experiment. The accuracy of this method is 2…6 %. The proposed technique will make it possible to assess the stress state of a new structural form of a frame with T-shaped support using measured deformations, which were determined as a result of experimental studies, as well as when assessing the stress state of operating frame structures.
Extraction of methylene blue coloring agent from model solutions with a plant-origin sorbent
Authors: Loktionova E V , Sysa O K , Loktionov V A 
Published: June 2021

Abstract
The production output of dyes and pigments in chemical industry is constantly increasing. Sewage waters, which contain synthetic and organic coloring agents, produce toxic effect, which is preconditioned by their low MAC values - below 0.001 mg/dm 2. The most promising method of the pigmented wastewater treatment, which allows reducing the pollutants’ content to the regulated permissible amount, is the adsorption method. This work presents research findings concerning sorption purification of test water media, containing methylene blue coloring agent, by using crop farming waste - chopped sunflower (Heliánthus ánnuus) stalks - as a sorption material. It has been determined that the maximum sorption capacity of chopped sunflower stalks biomass for this coloring agent is 0.245 mmol/dm 2. The processing of the received data has demonstrated that the obtained adsorption isotherm of methylene blue belongs to Type V isotherms according to classification by Brunauer-Deming-Deming-Teller (BDDT) or to the S-type, according to Giles’ classification. This adsorption process is the most accurately described by the Brunauer-Emmett-Teller model (BET), based on the concept of multilayer adsorption.
Fractal express methods evaluation of a breaking stress of concrete
Authors: Volchuk V M , Kotov M A 
Published: June 2021

Abstract
We have offered the methods of the operative evaluation of a breaking stress in testing strength on compression of heavy concrete of grade 400 with the use of fractal formalism. The methods are based on the setting of the relations of the values of a breaking stress and fractal measurement of concrete: 1. Areas with crushed stone prevailing (R2 = 0.7224); 2. Areas with sand prevailing (R2 = 0.6102); 3. Pin holes (R2 = 0.6874). During fractal experimenting the indexes of breaking were increased from 391.63 to 515.13 kH in reducing fractal dimension of areas 1 from 1.866 to 1.588; areas 3 from 1.826 to 1.684 and internal quality (boundary of its elements) from 1.617 to 1.353. Increase of fractal dimension was fixed only for areas containing sand (areas 2) from 1.755 to 1.944. These results make possible to apply fractal dimension as the indicator of structural changes of concrete in the prediction of its properties. In fractal modelling the accuracy of the results depends on the option of the task way for space metric that is proved by the obtained linear model (R2 = 0.9254), which describes the connection between the elements of macrostructure and strength criterion of concrete.
Such methods provide a satisfactory in practical purposes operative prediction for the values of breaking stress of concrete of grade 400 with significant reduction of time and money expenditures on full-scale testing and the application of microscopy.
Quality assurance in the design of heating systems in green building
Authors: Vinogradova N A , Plekhanova S V 
Published: June 2021

Abstract
The article considered the issue of thermal stabilization of buildings, formed a mathematical model for the room. The applied systems of thermoactive structures are described, their strengths and weaknesses are determined. Other methods of “passive” cooling systems are considered, it is determined that the main air conditioning systems are not fully used is technically and economically feasible, however, as complementary systems for the off-season must be taken into account. The heat supply system using a heat pump and a low-potential source (sewage) is described. This system allows for more efficient use of the evaporative-condensation cycle by operating with a smaller temperature difference between the heat pump flow and the low potential source. It is shown that the main attention should be paid to the development of alternative heating systems and the use of renewable energy sources. A significant part of the equipment used cannot always be considered as part of the overall strategy for the formation of an ecological building. The use of forms of heating based on low-potential sources will improve the environmental performance of residential and industrial buildings.
Comparison of the effectiveness of mineral and mixed coagulants in the lightening of water from a surface source
Authors: Grishin B M , Laskov N N , Perelygin Y P 
Published: June 2021

Abstract
The results of experimental studies of the coagulation treatment of the Sura River water in the autumn period and during high water with the use of mixed coagulants based on aluminum sulfate (AS), polyaluminum chloride “AQUA-AURAT 18” (PACl) and organic coagulant FL 4540 are presented. When treating river water with a low temperature, the use of mixed organic and mineral coagulants allows for a more significant reduction in the turbidity of the settled water compared to mineral coagulants AS and PACl at the same doses. Mixed coagulants with a weight ratio of FL 4540: AS (or FL 4540: PACl) equal to 1:4 have a greater efficiency of action compared to coagulants with a ratio of organic and mineral parts equal to 1:1. When treating low-turbidity water with a low temperature in the autumn period, the highest effect of clarification by settling was obtained using mixed coagulants based on PACl and FL 4540. At a standard mixing time of the initial river water with coagulants of 2 min, the use of a mixed coagulant K3 based on PACl and FL 4540 allows getting the same lightening effect as when using only PACl, but with doses lower by 30%. Experimental data on the coagulation treatment of the source water with low alkalinity and increased turbidity during the flood showed the greatest effectiveness of the mixed coagulant K1 based on AS and FL 4540, the use of which, with a mixing time of 2 minutes with the source water, reduces the dose of AS by 10% with the same settling effect. Increasing the mixing time with water to 15 minutes increases the effectiveness of the mixed coagulants, which in this case can reduce the doses of AS and PACl by 1.6-2 times without compromising the quality of clarified water by settling.