The theory of plasticity in the case of simple loading accompanied by strain-hardening

The author has previously shown that a deformation theory of plasticity is entirely adequate when the loading is simple; that is, when all the applied forces grow in proportion to a single parameter. The author now shows how a general plasticitytheory for any complex loading may be constructed by successively adding quantities of the nature of correction terms to the deformation theory. All of the theories of plasticity so far suggested for the complex loading condition are shown to be special cases of this general theory

Uprugo-plasticheskaya Ustoichivost Plasteen

This article explains results developed from the following research: 'The Stability of Plates and Shells beyond the Elastic Limit.' A significant improvement is found in the derivation of the relations between the stress factors and the strains resulting from the instability of plates and shells. In a strict analysis, the problem reduces to the solution of two simultaneous nonlinear partial differential equations of the fourth order in the deflection and stress function, and in the approximate analysis to a single linear equation of the Bryan type

Invariant Sets and Explicit Solutions to a Third-Order Model for the Shearless Stratified Turbulent Flow

We study dynamics of the shearless stratified turbulent flows. Using the method of differential constraints we find a class of explicit solutions to the problem under consideration and establish that the differential constraint obtained coincides with the well-known Zeman--Lumley model for stratified flows.Comment: arxiv version is already officia

Distribution Grid Future Planning under Uncertainty Conditions

The paper presents an approach for making decisions about the future development of a distribution grid under uncertainty conditions. The levels of a grid hosting capacity and adequacy are examined using probabilistic approach compared to the conventional deterministic fit-and-forget approach. It is shown that the probabilistic approach according to the 99 % confidence probability saves significant costs in comparison with the deterministic approach. The probabilistic calculations prove the use of an equipment rated capacity downsized by 2 points of a typical IEC scale, and in some cases to refuse the construction of a parallel circuit. The main contribution of the paper is a method for choosing an effective rated voltage of a distribution grid in a probabilistic interpretation based on the conventional formulas of Still, Zalessky and Illarionov. The technique includes obtaining the probability of loads location at different distances from power supply centre and the probability of load power distribution in a given range of values. It is shown that the calculation using the developed method makes possible to prefer grid rated voltage at least 1 point downsized by IEC scale with sufficient savings due to the difference in the equipment price compared with the deterministic fit-and-forget approach. © 2021, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.Proposed results are the outcome of work on the topic "Development and testing algorithms and technical solutions for digital control of power facilities" within integrated project "Improvement of approaches to digital management of power facilities"

Observational Results of a Multi-Telescope Campaign in Search of Interstellar Urea [(NH2_2)2_2CO]

In this paper, we present the results of an observational search for gas phase urea [(NH$_2$)$_2$CO] observed towards the Sgr B2(N-LMH) region. We show data covering urea transitions from $\sim$100 GHz to 250 GHz from five different observational facilities: BIMA, CARMA, the NRAO 12 m telescope, the IRAM 30 m telescope, and SEST. The results show that the features ascribed to urea can be reproduced across the entire observed bandwidth and all facilities by best fit column density, temperature, and source size parameters which vary by less than a factor of 2 between observations merely by adjusting for telescope-specific parameters. Interferometric observations show that the emission arising from these transitions is cospatial and compact, consistent with the derived source sizes and emission from a single species. Despite this evidence, the spectral complexity, both of (NH$_2$)$_2$CO and of Sgr B2(N), makes the definitive identification of this molecule challenging. We present observational spectra, laboratory data, and models, and discuss our results in the context of a possible molecular detection of urea.Comment: 38 pages, 9 Figures, accepted in the Astrophysical Journa

Estimating distributed generation reliability level

The paper considers the reliability level of different distributed generation units. The world comparative statistics of reliability parameters depending on the unit capacity and other influencing factors are presented. The study includes an analysis of possible approaches to the correction of statistical parameters under the particular conditions. The calculation and analysis of structural reliability parameters for a group of distributed generation units is performed. It is shown that conventional N+1 reliability principle is not enough for distributed generation given a great number of operation conditions. A set of N+n principles is proposed according to the required distributed generation reliability level. Considering the reliability parameters is of great importance for the selection of installed power and the structure of distributed generation for industrial and household facilities under the design and evaluation of its technical and economic efficiency. Gradual growth of the share of distributed generation in power and energy balances of power systems raises the issue of its reliability calculation and regulation. The results obtained in the paper are also important for the maintenance, planning of repairs, and providing necessary logistics solution for the delivery of spare parts and consumables to generating plants. © European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006

Creation of composite bronze-maraging steel alloy

The possibility is demonstrated of creating alloys based on the system Cu-Fe-Ni-Al, within which the matrix is bronze BrNA 4-1, "reinforced" with dendrites containing, apart from Fe and Cu, about 15% Ni and 1% Al. This dendrite composition provides dispersion hardening. Favorable dendrite morphology provides high deformability of these bronzes, and makes it possible to control mechanical and service properties by heat treatment over a wide range. © 2013 Springer Science+Business Media New York

Sensitivity to a possible variation of the proton-to-electron mass ratio torsion-wagging-rotation transitions in methylamine CH3NH2

9 x 10(-6) is deduced

Analysis of solid conductors by means of Voronoi-Dirichlet partition

n/