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•A layered composite material based on TiAl/TiB2 has been first obtained by unrestricted SHS-compression.•The Ti1.87B50 phase and the MAX-phase of the Ti2AlN composition were ...synthesized.•The hardness of the material on the surface increased by 6.3 times.
In this work, a layered composite material based on TiAl/TiB2 has been first obtained by unrestricted SHS-compression on the titanium alloy Ti6Al4V from the initial powders of titanium, aluminum, and boron. The structural features and phase composition of the layered composite material have been studied, the dimensions of each layer and the diffusion boundaries between the layers have been determined, and the hardness of each layer has been measured. It has been found that the surface hardness of the layered material is 9.5 GPa, and as approaching titanium alloy Ti6Al4V, it gradually decreases to the hardness of the alloy itself (1.5 GPa). For the first time, under the conditions of combustion and subsequent high-temperature deformation, compound Ti1,87B50 and the MAX-phase of the Ti2AlN composition have been synthesized.
Abstract
To estimate the derivatives of a deterministic signal arriving in real time, a state observer is introduced, built as a replica of the virtual canonical model with an unknown bounded input. ...The results of a comparative analysis of observers with linear and piecewise linear corrective actions are presented, which are confirmed by the results of numerical modeling for piecewise differentiable composite function. Its derivatives have jump discontinuity points at the moments when the form of the function changes. It is shown that at these moments the observer variables with linear corrective actions with high gains have large surges, which increase by an order of magnitude with an increase in the order of the estimated derivative. Observers with bounded piecewise linear corrective actions do not have these problems and are recommended for use in practical applications.
We present the concept of multifunctional nanoengineered polymer capsules and outline their applications as new drug delivery systems or supramolecular toolboxes containing, for example, enzymes ...capable of converting nontoxic prodrugs into toxic drugs at a designated location. Such functionalized nanocontainers offer a wide range of applications including enzymatic catalysis, controlled release, and directed drug delivery in medicine due to their multifunctionality. The unique advantage of capsules in comparison to other systems is that they can be functionalized or loaded simultaneously with the above‐mentioned components, thus permitting multifunctional processes in single cells.
Getting to the point: Polymer microcapsules exhibit many useful properties in the area of nanobiotechnology. Careful design can allow such materials to contain specific enzymes or agents, be transported to the area of need, and deliver that enzyme or agent in a specific and safe manner. The picture shows polymer capsules loaded with fluorescent CdTe quantum dots that have been taken up by a human breast cancer cell.
The High Luminosity (HL) upgrade of the Large Hadron Collider (LHC) will increase the peak luminosity at the experiments by more than a factor of 5 with respect to the LHC design value. To achieve ...this goal, among the upgrade of several beam and machine parameters, the beam intensity will nearly double with respect to the operational LHC value, and the transverse beam emittance will decrease by 50% compared to the LHC design value. Past operational experience showed that coherent beam instabilities may occur for low, positive values of chromaticity, and a higher tune spread than predicted from simulations is required from the dedicated octupole magnets to provide enough Landau damping. With the HL-LHC brighter beams, stability margins will become tighter, and coherent instabilities become stronger if no dedicated mitigation measures are taken. An impedance reduction plan is therefore taking place targeting the collimation system, and the main contributor to the transverse beam coupling impedance at the flattop energy. New collimators with lower resistivity materials will replace the current LHC ones. In this work, we assess the benefits of this impedance reduction with respect to the transverse mode coupling instability threshold. This study quantifies the discrepancy between measured and predicted beam stability thresholds at low chromaticity. It also probes the expected gain of the impedance reduction plan of HL-LHC.
This magnetic, clay minerals and palynological study provides a record of two Late Pleistocene transgressions (Late Khazarian and Early Khvalynian) in the Caspian Sea, through the analysis of ...present-day lower Volga terraces. The results allow the clarification of some points about the Caspian Sea evolution during the considered periods. Early diagenetic iron sulphides (greigite and pyrite) are present in sediments of the lower part of the Late Khazarian and reflect restricted water circulation in the basin. The change in iron sulphide mineralogy is most probably related to the change of the water level and its salinity. Low magnetic mineral contents with magnetite, if any, recorded in the upper part of the Late Khazarian, Atelian and Early Khvalynian, reflect a well-oxygenated basin and detrital material sources poor in magnetic minerals. Smectite is the dominant clay mineral in the Late Khazarian, reflecting chemical weathering in its source area due to the wet and warm climate. The upper part of this transgression is nevertheless marked by a stepwise relative decrease of smectite and an increase of illite, attributed to a cooling climate. During the Atelian and Early Khvalynian periods, phases of sandy deposits are characterised by equal proportions of illite and smectite, similar to Ukrainian loess. “Chocolate” clays are clearly dominated by illite. Both clay mineralogies are attributed to cool climate, which favours physical weathering in the catchment area. The conditions of “chocolate” clays deposition are unclear. The recorded cooling during the last phase of the Late Khazarian and the 14C age on a well-preserved bivalve shell, suggest that it is probably much younger than the Eemian interglacial, and could correspond to the Girkan transgression. The 14C age for the Early Khvalynian sample suggests approximately a Last Glacial Maximum age for this transgression.
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