A method for fabricating microvascular networks in fiber‐reinforced composites is presented. The method relies on sacrificial fibers woven into fiber preforms that, when removed by depolymerization ...and volatilization, create 3D microvascular networks inside the composite material. By circulation of functional liquids in the resulting channels, a diverse set of new functionality is demonstrated. Simplicity, robustness, scalability, and reliance on readily available components make this method compatible with composite manufacturing methods.
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In this work, the effect of ball milling of synthesized LiFe
5
O
8
ferrite powders on the microstructure and properties of ferrite ceramics was studied by XRD, laser diffraction and SEM analysis as ...well as thermal analysis. The mechanical milling of LiFe
5
O
8
was carried out in a Fritsch Pulverisette 7 planetary mill using the zirconia or steel grinding balls. The process of ferrite sintering was investigated using dilatometric analysis. In addition, ferrite ceramics electromagnetic properties, including magnetization, Curie point and electrical resistivity, were investigated. The results showed a strong difference in the structure of ferrite ceramics obtained from ferrite powders pre-milled by zirconia or steel grinding balls. Thus, the milling results in a decrease in the particle size of the ferrite powders to ultrafine range. The ferrite ceramics, obtained from powder milled by steel balls, is characterized by high density and low porosity as well as good electromagnetic properties and the main presence of a disordered β-LiFe
5
O
8
phase. However, the mechanical milling using zirconia balls leads to the contamination of ferrite by zirconia, resulting in the formation of β-LiFe
5
O
8
/ZrO
2
composite ceramics during sintering.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Constraint-based reconstruction and analysis (COBRA) provides a molecular mechanistic framework for integrative analysis of experimental molecular systems biology data and quantitative prediction of ...physicochemically and biochemically feasible phenotypic states. The COBRA Toolbox is a comprehensive desktop software suite of interoperable COBRA methods. It has found widespread application in biology, biomedicine, and biotechnology because its functions can be flexibly combined to implement tailored COBRA protocols for any biochemical network. This protocol is an update to the COBRA Toolbox v.1.0 and v.2.0. Version 3.0 includes new methods for quality-controlled reconstruction, modeling, topological analysis, strain and experimental design, and network visualization, as well as network integration of chemoinformatic, metabolomic, transcriptomic, proteomic, and thermochemical data. New multi-lingual code integration also enables an expansion in COBRA application scope via high-precision, high-performance, and nonlinear numerical optimization solvers for multi-scale, multi-cellular, and reaction kinetic modeling, respectively. This protocol provides an overview of all these new features and can be adapted to generate and analyze constraint-based models in a wide variety of scenarios. The COBRA Toolbox v.3.0 provides an unparalleled depth of COBRA methods.
•A new method is developed quantitative phase control in soft ferrimagnetic materials.•The method is based on thermomagnetometric analysis of the samples in magnetic field.•This method compared to ...X-ray diffraction analysis is more precise.•The method was successfully tested on the LiTi and LiZn ferrites.
In this work, the method of quantitative ferrite phase control, which is based on thermomagnetometric analysis of the ferrite samples in magnetic field, was developed. The magneto-phase transitions in LiZn and LiTi ferrites with chemical formulas Li0.5(1x)Fe2.50.5xZnxO4 and Li0.5(1+x)Fe2.51.5xTixO4 were studied, and their phase compositions were analyzed by both the developed method and X-ray diffraction analysis. It was shown that the thermomagnetometry method compared to X-ray diffraction analysis allows to examine more precisely the magnetic phases in synthesized ferrites with inhomogeneous phase composition. However, a complex analysis, using both X-ray and thermomagnetometry methods, will be the most optimal in case of the formation of non-magnetic and poor magnetic phases.
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The sufficient conditions for the existence of an optimal thickness of an orthotropic dividing wall are determined with the zero-order Hankel integral transform. Both wall surfaces participate in a ...heat transfer with external media with constant temperatures, and one of them is also affected by a stationary axisymmetric heat flux with a Gaussian-type intensity. The need to minimize the temperature of the most heated point of the object of study is used as an optimality criterion. A sufficient condition is obtained in the form of an inequality that establishes a connection between the thermophysical characteristics of the orthotropic material of the wall and the parameters of the external thermal effects. The accuracy of the obtained condition was established by a computational experiment.
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The electrohydrodynamic (EHD) structure of flow of a high-temperature partially ionized chemically reacting gas mixture through in a plane channel is considered. The plume of hydrocarbon flame at the ...atmospheric pressure can be an example of such a flow. It is well known that the chemiionization reactions are the source of charged particles in the combustion processes. Clearly, there is a strong spatial inhomogeneity of the ionization source on the boundaries of the combustion zone. It is shown that in this case narrow zones of space electric charge (similar to the bipolar double layers) are formed in the neighborhood of the boundaries and the Coulomb forces that act on the behavior of the burning medium appear here even in the absence of the external applied electric field. The regime of combustion in which the major part of the plume becomes positively charged is revealed.
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In a present work, a comparative study of two types of LiTiZn samples of ferrite ceramics, which were sintered using conventional ceramic technology at a temperature of 1010 °C for 2 h and which were ...made with preliminary mechanical treatment in a ball planetary mill, was carried out. It is shown that mechanical treatment in a ball mill leads to a decrease in the defects level, an increase in the Curie point and a demagnetizing factor of ferrite ceramics. The growth of the demagnetizing factor is associated with an increase in the porosity of ferrite ceramics samples pre-grinded in ball. According to the X-ray phase analysis data, the lattice parameter and the coherent scattering region decrease in this case, and the microstrain is reduced by an order of magnitude. The defects level was assessed by the results of mathematical processing of the temperature dependences of the initial permeability using the previously proposed phenomenological expression. Measuring TG/DTG curves in a magnetic field allowed, on the one hand, to confirm a significant difference in Curie points for different types of samples, on the other hand, to detect the presence of an additional magnetic phase in ball-milled ferrite ceramics samples.
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—The “pump-probe” scheme considers oscillations of magnetization in a normally magnetized plate with magnetoelastic properties, which occur under the action of an elastic pulse excited by a powerful ...pulsed laser. The time evolution of magnetic oscillations excited by an elastic pulse is studied, and the corresponding precession portraits are constructed. For the case where the resonant frequencies of magnetic and elastic oscillations coincide and the relaxation times of both are close, three characteristic regimes are noted in which magnetization oscillations are nonstationary, corresponding to small, medium, and high amplitudes of the exciting pulse. The features of the observed phenomena are interpreted based on the impact nature of the excited elastic oscillations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
The paper is aimed to analyse the labour mobility in the region using GIS services. Within the framework of the project, a methodology for continuous automatic collection and accumulation of ...information on the state of the transport network and weather conditions was developed, tested and implemented. Based on this information, it is possible to analyse the important factors of the regional economy: temporary and financial losses of residents of the Moscow Region on the home-to-work paths, as well as identify patterns of traffic congestion from various factors. The first results of the analysis of the accumulated data are presented, which demonstrate the commuting effects in the regional transport network.
The ignition of a stoichiometric ethylene−oxygen mixture diluted with argon was experimentally and computationally studied to gain new insights into the nature of the chemiluminescence that ...accompanies this process and to obtain some of its quantitative characteristics. The experiments were performed behind reflected shock waves at temperatures of 1270−1820 K and a pressure of ~1 bar. The time evolution of the luminescence intensity of the electronically excited C
2
*, CH*, and OH* radicals and CO
2
* molecule was monitored photometrically. The measured temperature dependence of the ignition delay time was found to be in satisfactory agreement with the published data and the results of simulations within the framework of the ChemphysMech_v.1 (Tereza et al., 2010) and AramcoMech_1.3_C
4
(Metcalfe et al., 2013) reaction mechanisms. The possible reaction pathways of formation of C
2
*, CH*, OH*, and CO
2
* were analyzed. It was shown for the first time that, along with the recombination reaction CO + O → CO
2
*, CO
2
* is formed by the reaction CH + O
2
→ CO
2
* + H, which dominates during fuel burnout, whereas the former becomes the main channel of CO
2
* formation at later stages. The contribution from the reaction C
2
H + O
2
was demonstrated to play a minor role in the formation of CH* as compared to the C
2
H + O reaction, at least under the conditions tested.
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