For various materials, rapid generation of results is always critical. Particle-size analysis of processing products using a laser-based particle-size analyzer is a valid alternative to the ...traditional sizing test. The article presents the results of studies conducted using Microsizer 201C equipment by the example of layered aluminosilicates and metal powders for additive manufacturing. The size analysis for these products is generally complicated by their ability to stick and agglomerate. Ultrasonic mixing does not harm the material analyzed and promotes uniform distribution of the sample during analysis. The results of granulometric analysis of kaolin ores obtained after different heat treatment are presented. The results of air-electric classification of metal powders obtained after vibration disintegration of metal chips are presented. The variety of raw materials shows a wide range of applications of this method in industry.
A consistent approach to the optimal selection of replacement technologies is required in industrial production. A conceptual framework for formalized representation of production technologies is ...outlined. The diversity of external and internal disturbances is discussed. Types of technological substitution are classified. The structure of a decision support system (DSS) and the content of its intellectual core are defined in the form of a high-level mathematical toolkit. Practical experience with the proposed tools in technological replacement is outlined.
In this paper, we study long-term changes in the main directions of movement (storm tracks) of extratropical cyclones in the North Atlantic over the period 1873–2021. It was found that in the cold ...half of the year (the period of the most intense cyclogenesis), the average latitudes of storm tracks in the longitudinal range from 60° to 10° W experience oscillations with periods ∼80–100, ∼40–47, and ∼22 years, indicating their possible association with solar activity variations. The trajectories of cyclones were shifted to the north at the minimum of the Gleissberg secular cycle (∼1900–1930) and to the south at the cycle maximum (∼1940–1960). The secular changes in storm track latitudes amount to ∼3°–5° in the western part of the North Atlantic (the area of formation and the most intensive development of cyclones). On the bidecadal scale, a northward shift of cyclone trajectories in even solar cycles and a southward shift in odd ones were found. The shift of cyclone trajectories to the north in even cycles reached maximal values (∼1°–2° relative to a secular variation) at the descending branch and the minimum of the solar cycle (2nd−6th years after the maximum) in the eastern part of the North Atlantic. Changes in intensity of the stratospheric polar vortex, caused by variations in galactic cosmic rays and geomagnetic activity, are a possible reason for oscillations in cyclone trajectories.
The t(8;21)(q22;q22) rearrangement represents the most common chromosomal translocation in acute myeloid leukemia (AML). It results in a transcript encoding for the fusion protein AML1-ETO (AE) with ...transcription factor activity. AE is considered to be an attractive target for treating t(8;21) leukemia. However, AE expression alone is insufficient to cause transformation, and thus the potential of such therapy remains unclear. Several genes are deregulated in AML cells, including KIT that encodes a tyrosine kinase receptor. Here, we show that AML cells transduced with short hairpin RNA vector targeting AE mRNAs have a dramatic decrease in growth rate that is caused by induction of apoptosis and deregulation of the cell cycle. A reduction in KIT mRNA levels was also observed in AE-silenced cells, but silencing KIT expression reduced cell growth but did not induce apoptosis. Transcription profiling of cells that escape cell death revealed activation of a number of signaling pathways involved in cell survival and proliferation. In particular, we find that the extracellular signal-regulated kinase 2 (ERK2; also known as mitogen-activated protein kinase 1 (MAPK1)) protein could mediate activation of 23 out of 29 (79%) of these upregulated pathways and thus may be regarded as the key player in establishing the t(8;21)-positive leukemic cells resistant to AE suppression.
Recently, the concept of supersonic
N
-crowdions was offered. In molecular dynamics simulations, they can be excited by initial kick of
N
neighboring atoms located in one close-packed atomic row ...along this row. In the present study, in 2D Morse crystal, we apply initial kick to
M
neighboring atoms located in neighboring close-packed atomic rows along these rows. This way, we initiate crowdion clusters called subsonic
M
-crowdions. It is well known that static 1-crowdion in 2D Morse lattice is unstable; as a result, the interstitial atom leaves the close-packed atomic row and becomes immobile. However, we show that 1-crowdion moving with sufficiently large subsonic velocity remains in the close-packed atomic row. Crowdion clusters with
M
equal to or greater than 2 appear to be stable even at rest, with growing
M
transforming into prismatic dislocation loops. It is important to note that stable subsonic
M
-crowdions (
M
> 1) remain mobile and they can carry interstitial atoms over long distances.
An important aspect of ensuring national security is state regulation of industry through federal institutes. In view of the scale of the threats to Russia’s national security, the constraints on ...federal resources, and the critical state of industrial enterprises, it is important to review the strategy and tools of state regulation. In particular, a change in orientation is required, with a focus on novel and nontraditional organizational and economic programs and with cross-financing of defense and civilian projects. However, that is associated with changes not only in the procedures for assessing the effectiveness of such programs but also in the concept of effectiveness itself. Accordingly, it is necessary to deal with a set of concepts and characteristics of effectiveness and also to develop basic procedures for the assessment of effectiveness. That reduces to assessing the expected results of an innovative project and the effectiveness of its implementation. A method for generating such predictive estimates is proposed.
It has been shown recently that a moving discrete breathers localized in one close-packed atomic row can be excited in a two-dimensional monoatomic crystal with Morse interaction. In this work, a ...motionless discrete breathers having the threefold symmetry axis has been excited in the same crystal. The initial conditions for the excitation of such discrete breathers are set by the superposition of a bell-shaped function on a planar nonlinear phonon mode with the wave vector lying at the edge of the Brillouin zone. In addition, the displacement of the centers of atomic oscillations from the center of the discrete breathers owing to the asymmetry of the Morse potential is taken into account. The results obtained make it possible to approach the search for highly symmetric discrete breathers in three-dimensional crystals.
The dynamics of a three-component nonlinear delocalized vibrational mode in graphene is studied with molecular dynamics. This mode, being a superposition of a root and two one-component modes, is an ...exact and symmetrically determined solution of nonlinear equations of motion of carbon atoms. The dependences of a frequency, energy per atom, and average stresses over a period that appeared in graphene are calculated as a function of amplitude of a root mode. We showed that the vibrations become periodic with certain amplitudes of three component modes, and the vibrations of one-component modes are close to periodic one and have a frequency twice the frequency of a root mode, which is noticeably higher than the upper boundary of a spectrum of low-amplitude vibrations of a graphene lattice. The data obtained expand our understanding of nonlinear vibrations of graphene lattice.
Planar superstructure defects (PSDs) have a great influence on the mechanical and functional properties of ternary Heusler alloys, but a complete analysis of their structure and energy is lacking in ...the literature. In this work, for Heusler alloys of stoichiometric composition X2YZ, having the L21 superstructure, expressions are given for calculating the sublimation energy and the energy of an arbitrary PSD under the assumption of hard coordination spheres and pair interatomic interactions. It is shown that for a given crystallographic orientation there cannot be more than three PSDs with different energies. An expression is given for finding the planes of occurrence of all possible conservative antiphase boundaries (APBs). It is established that in Heusler alloys there are only conservative and nonconservative APBs and there are no defects such as boundaries of C-domains or inversion APBs. The results obtained are useful for the analysis of slip systems and the configuration of magnetic domain walls of the considered family of alloys.
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•Structure and energy of planar superstructure defects in Heusler alloys are analyzed.•Heusler alloys support only conservative and nonconservative antiphase boundaries.•List of crystallographic planes with conservative antiphase boundaries is given.•In each plane no more than three defects with different energy can exist.•Energy of any planar superstructure defect is given in terms of pair potentials.
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