homogeneous state
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2021 ◽  
Author(s):  
Agnieszka Skóra

In this paper, I aim at presenting the language situation of some regional minorities in Poland: Silesians (Ślązacy), Kashubians (Kaszubi) and the residents of Wilamowice. Protection of language minorities is extremely important from the point of view of cultural development of countries. Throughout a long period of its existence, Poland has been a multi-cultural country populated by representatives of different national, regional and ethnic groups. However, the national and ethnic situation of Poland changed radically after the Second World War. Today Poland is one of the most homogenous states not only in Europe but also worldwide. However, Poland is not free from the discussion about minority rights. Shaping a strong regional identity, which was particularly true for the Silesians and Kashubians and residents of Wilamowice, was a social and cultural phenomenon, completely unknown in the long history of Poland. The Act on national and ethnic minorities and on the regional languages dated January 6, 2005, allows to use of Kashubian language as a “supporting language” before the municipality authorities, the smallest ad-ministrative unit. The other obvious point of this description concerns the demanding of similar linguistic rights by Silesians. The study also highlights the efforts of the residents of Wilamowice to preserve their unique language.


Author(s):  
Jintao Sun ◽  
Qi Chen ◽  
Baoming Zhao ◽  
Caohui Guo ◽  
Jianyu Liu ◽  
...  

Abstract Ion chemistry with temperature evolution in weakly ionized plasma is important in plasma-assisted combustion and plasma-assisted catalysis, fuel reforming, and material synthesis due to its contribution to plasma generation and state transition. In this study, the kinetic roles of ionic reactions in nanosecond discharge (NSD) plasma-assisted temperature-dependent decomposition and oxidation of methane are investigated by integrated studies of experimental measurements and mathematical simulations. A detailed plasma chemistry mechanism governing the decomposition and oxidation processes in a He/CH4/O2 combustible mixture is proposed and studied by including a set of electron impact reactions, reactions involving excited species, and ionic reactions. A zero-dimensional model incorporating the plasma kinetics solver ZDPlasKin and the combustion chemical kinetics solver CHEMKIN is used to calculate the time evolution of the ion density. Uncertainty analysis of ionic reactions on key species generation is conducted by using different referenced data, and insignificant sensitivity is found. The numerical model is consistent with experimental data for methane consumption and generation of major species including CO, CO2, and H2. By modeling the temporal evolution of key ions, it is observed that O2+ presents the largest concentration in the discharge stage, followed by CH4+, CH3+, and CH2+, which is in accordance with the traditional ion chemistry in hydrocarbon flames and agrees well with molecular-beam mass spectrometer investigations. The path flux shows that the concentrations of key species, including electrons, O, OH, H, O(1D), O2(a1Δg), O2+, CH3+, and CH4+, change within 1–2 orders of magnitude and that the transition from a homogeneous state to a contracted/constricted state does not occur. The path flux and sensitivity analysis reveal the significant roles of cations in the stimulation of active radical generation, including CH, O, OH, and O(1D), thus accelerating methane oxidation. This work provides a deep insight into the ion chemistry of temperature-dependent plasma-assisted CH4 oxidation.


Author(s):  
Сергей Петрович Баутин ◽  
Юрий Владимирович Николаев

Выполнено численное моделирование одномерных течений политропного газа, описывающее сжатие покоящегося газа с плотностью 1 в покоящийся газ, сжатый до значения 10. Описываемое сжатие происходит без ударных волн эффективным с точки зрения энерговложения способом, так как энергия тратится только на сжатие газа, но не на его разгон Controlled thermonuclear fusion (CTF) is an almost unlimited source of energy and scientists have been studying it for several decades. This requires an efficient and stable compression of diyterium-tritium fuel to a very high density. This work addresses shockless one-dimensional (plane, cylindrical and spherical symmetry cases) “compression from rest to rest”, when gas from the initial resting state under the influence of an impenetrable piston is shocklessly transferred to a resting homogeneous state, but compressed by 10000 times. This compression is energetically most advantageous, because work is spent only on the compression, but not on the gas acceleration. Earlier [10] this problem was solved in the opposite direction of time change. In this case, a density jump occurs on the piston which was taken into account in calculations [3] at the final moment of compression. The numerical solution of this problem in the opposite direction of time variation allows calculating the trajectory of the compressing piston in the form of a set of points ( t,r ) at which the gas velocity and density are determined. In this paper, the problem of shockless “compression from rest to rest” is numerically solved in the forward direction of time change if the compressing piston trajectory is known. The compression piston moves along a monotonous trajectory away from the axis or center of symmetry. It is important, when calculating in forward direction of time change, no internal characteristics are initially entered. They, like all gas flow in the calculation area, are determined in the process of direct calculation. This indicates that the trajectory of compressing piston is the recommendation for appropriate physical experiments


2021 ◽  
Author(s):  
Ligui Xiong ◽  
Liqiong Zhang

Konjac glucomannan (KGM) and poly (vinyl alcohol) (PVA) were mixed to form gel-like polyelectrolyte solution with glycerol and sorbitol as compound plasticizer, which was used to prepare packaging films via casting and drying. The results show that the tensile strength and elongation at break of the packaging films drop sharply when the blending temperature and blending time exceed 80 °C and 3.5 h. When the mass ratio of sorbitol and glycerol in the compound plasticizer ranges from 1:1 to 1:3, it is beneficial to improve the tensile strength of the packaging films. The microscopic reasons for the change of the tensile properties of the packaging films are mainly caused by diffusion-stop-continuing diffusion—precipitation of low-molecular electrolyte, which makes the system shift from equilibrium-homogeneous state- unbalanced state—heterogeneous state.


2021 ◽  
Vol 17 (4) ◽  
pp. 15-23
Author(s):  
T. V. Alexeeva ◽  
E. S. Popov ◽  
L. A. Albycheva ◽  
Yu. O. Kalgina

The article presents the results of studies on the effect of a bio-correcting food supplement on functional and technological properties of model liver-based pate systems. The supplement included components that are domestic resource-saving sources with predictable biopotential and consumer properties. The food-fortifying supplement was added to the model pate systems in the amount of 10–30%. The aim of the research is to study the effect of bio-correcting supplement on functional and technological properties of liver pate products. Technology of preparing model minced meat systems, along with traditional operations, included the stage of introducing a bio-correcting supplement into the cutter. It has been found that dry supplement components must be hydrated when used in the composition of pate recipes. The process of hydration of the enriching supplement was carried out with drinking water in the ratio of 1:2, and was stirred to a homogeneous state, then kept at the temperature of 19 ± 5°C for 10–15 minutes. That corresponded to the state of saturation of the system biopolymers with moisture and achievement of a pasty consistency, similar to that of pate masses. In the course of the research it was found that the model compositions had higher indicators of functional and technological properties compared with the control ones. The enriching additive in the composition of liver pate increased up to 30% compared with the samples prepared according to the traditional recipe: the moisture-binding capacity by 11–20%, the water-holding capacity by 20–25%, and the emulsifying capacity by 9–14%. The results obtained indicate the possibility of a targeted influence of the additive components on the functional and technological properties of liver pate. When a bio-correcting additive is included in liver pates, the pates get enriched with high-grade protein, vitamins, minerals and essential substances; organoleptic properties of finished products improve; calorie content of products reduces; functional, technological, structural and mechanical properties improve; the risk of broth-fat edema and moisture release from food products reduces; thermal losses decrease and the yield of finished products increases; a new product line of pates with high biopotential and consumer properties is obtained.


2021 ◽  
Author(s):  
Simon Stephan ◽  
Jens Staubach ◽  
Hans Hasse

The Lennard-Jones (LJ) potential is widely used for describing simple fluids; it is also a point of departure for developing models of complex fluids. Thermodynamic properties of the LJ fluid have been studied by molecular simulations by many authors and a critical review of the available data, which comprises about 35,000 data points, has been published recently [J. Chem. Inf. Mod. 59 (2019) 4248–4265]. The importance of the LJ fluid has also triggered the development of a large number of equations of state (EOS). In the present work, 20 LJ EOS were critically assessed by comparing their results with consolidated data from computer experiments. A large variety of thermophysical properties was considered: vapor pressure; saturated densities; enthalpy of vaporization; critical properties; thermal, caloric, and entropic properties at homogeneous state points; and second and third virial coefficients. It was found that none of the available LJ EOS meets the following two criteria: (1) it does not yield unphysical artifacts when used for extrapolations, and (2) it describes data from computer experiments within their statistical uncertainty in most fluid regions. Furthermore, a re-parameterization of the monomer term of the PC-SAFT EOS was carried out by fitting it to data of the LJ fluid. The new LJ EOS yields good results for the LJ fluid, but does not outperform the best existing LJ EOS.


Author(s):  
Feng Dai ◽  
Bin Liu

This paper deals with the Keller–Segel–Navier–Stokes model with indirect signal production in a three-dimensional (3D) bounded domain with smooth boundary. When the logistic-type degradation here is weaker than the usual quadratic case, it is proved that for any sufficiently regular initial data, the associated no-flux/no-flux/no-flux/Dirichlet problem possesses at least one globally defined solution in an appropriate generalized sense, and that this solution is uniformly bounded in [Formula: see text] with any [Formula: see text]. Moreover, under an explicit condition on the chemotactic sensitivity, these solutions are shown to stabilize toward the corresponding spatially homogeneous state in the sense of some suitable norms. We underline that the same results were established for the corresponding system with direct signal production in a well-known result if the degradation is quadratic. Our result rigorously confirms that the indirect signal production mechanism genuinely contributes to the global solvability of the 3D Keller–Segel–Navier–Stokes system.


2021 ◽  
Author(s):  
Bi Liu ◽  
Xia Wang ◽  
Linan Jiang ◽  
Jianhua Xu ◽  
Yitshak Zohar ◽  
...  

ABSTRACTThe balance between cell quiescence and proliferation is fundamental to tissue physiology and homeostasis. Recent studies have shown that quiescence is not a passive and homogeneous state but actively maintained and heterogeneous. These cellular characteristics associated with quiescence were observed primarily in cultured cells under a static medium. However, cells in vivo face different microenvironmental conditions, particularly, under interstitial fluid flows distributed through extracellular matrices. Interstitial fluid flow exerts shear stress on cells and matrix strain, and results in continuous replacement of extracellular factors. In this study, by analyzing individual cells under varying fluid flow rates in microfluidic devices, we found that extracellular fluid flow alters cellular quiescence depth through flow-induced physical and biochemical cues. Specifically, increasing the flow rate drives cells to shallower quiescence and become more likely to reenter the cell cycle upon growth stimulation. Furthermore, we found that increasing shear stress or extracellular factor replacement individually, without altering other parameters, also results in shallow quiescence. We integrated the experimental results into a mathematical model to gain insight and predict the effects of varying extracellular fluid flow conditions on cellular quiescence depth. Our findings uncover a previously unappreciated mechanism that likely underlies the heterogeneous responses of quiescent cells for tissue repair and regeneration in physiological tissue microenvironments.


2021 ◽  
pp. 211-233
Author(s):  
Edward Fowler
Keyword(s):  

Author(s):  
Damià Gomila ◽  
Edgar Knobloch

Abstract In this work, we revisit some general results on the dynamics of circular fronts between homogeneous states and the formation of localized structures in two dimensions (2D). We show how the bifurcation diagram of axisymmetric structures localized in radius fits within the framework of collapsed homoclinic snaking. In 2D, owing to curvature effects, the collapse of the snaking structure follows a different scaling that is determined by the so-called nucleation radius. Moreover, in the case of fronts between two symmetry-related states, the precise point in parameter space to which radial snaking collapses is not a ‘Maxwell’ point but is determined by the curvature-driven dynamics only. In this case, the snaking collapses to a ‘zero surface tension’ point. Near this point, the breaking of symmetry between the homogeneous states tilts the snaking diagram. A different scaling law is found for the collapse of the snaking curve in each case. Curvature effects on axisymmetric localized states with internal structure are also discussed, as are cellular structures separated from a homogeneous state by a circular front. While some of these results are well understood in terms of curvature-driven dynamics and front interactions, a proper mathematical description in terms of homoclinic trajectories in a radial spatial dynamics description is lacking.


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