Die equipment and tool for manufacturing sandwich flat ring parts with composites

The results of designing die equipment and special tool through separate die operations for manufacturing sandwich flat ring parts with the middle base metal layer and periphery elastic layers with increased composite thickness are shown. Efficient geometrical dimensions and a tool shape ensuring qualitative manufacturing parts mentioned and extension of technological potentialities of separating operations for their manufacturing, in particular, for design options with the increased thickness of periphery elastic composite layers are optimized experimentally.

Dynamics of a Conductor with Unclosed Alternative Electric Current

The ponderomotive interaction of displacement currents and conduction currents in an open conductor through which an alternating electric current flows is considered. The calculation is performed for a flat conductor of arbitrary shape. It has been shown that the displacement current does not create a nonzero force that would act on an open conductor. The so-called force of self-action, with which the conductor acts on itself, is compensated by the force of Abraham, transmitted to the electromagnetic field. The absolutely exact fulfillment of the law of conservation of momentum, which includes the latent momentum of the field, has been demonstrated. The density of Abraham's force is determined by the vector product of the derivative of the electric field in-duction by the magnetic field induction. As an example, a numerical calculation of the self-force and the Abraham force for a thin ring conductor is carried out. The ratio of Abraham's force to the square of the conduction current depends only on the relative dimensions of the conductor. The maximum Abraham's force is observed for a conductor representing half of a flat ring.

Flat ring epimorphisms and universal localizations of commutative rings

We study different types of localizations of a commutative noetherian ring. More precisely, we provide criteria to decide: (a) if a given flat ring epimorphism is a universal localization in the sense of Cohn and Schofield; and (b) when such universal localizations are classical rings of fractions. In order to find such criteria, we use the theory of support and we analyse the specialization closed subset associated to a flat ring epimorphism. In case the underlying ring is locally factorial or of Krull dimension one, we show that all flat ring epimorphisms are universal localizations. Moreover, it turns out that an answer to the question of when universal localizations are classical depends on the structure of the Picard group. We furthermore discuss the case of normal rings, for which the divisor class group plays an essential role to decide if a given flat ring epimorphism is a universal localization. Finally, we explore several (counter)examples which highlight the necessity of our assumptions.

METHOD FOR MEASURING THE PRESSURE OF A SHOCK-ACOUSTIC WAVE OF AN ELECTRIC EXPLOSION OF A CONDUCTOR IN A DISCHARGE CHAMBER WITH A CONDENSED ENVIRONMENT

An electric explosion of conductors, as well as an electric discharge as a whole, is a poorly studied unique phenomenon that is widely used both in basic scientific research and in various technological processes, which determines the relevance of further studies of ongoing processes. In this paper, we consider the methods and carry out calibration procedures to determine the value of the conversion coefficient for a piezoelectric pressure transducer with a reactive acoustic waveguide made of non-Newtonian fluid material. Designs of calibration plants are shown, the principle of which is based on the method of falling load and the interaction of parallel currents. The results of recording and measuring the pressure of a shock acoustic wave (SAW) generated by an electric explosion of a metal conductor of a ring-shaped geometry in a closed space of conical geometry with a condensed (aqueous) medium are presented. The discharge current and the voltage drop across the exploding flat ring foil (EEFRF) were recorded by the Rogowski belt and voltage divider, respectively. The pressure pulse of the acoustic shock wave was recorded by a piezoelectric pressure transducer. The electrical signals were recorded with a GDS-810 S digital two-beam storage oscilloscope. The amplitude value of pressure was estimated by plastic deformation of the plate sensor in the form of a round thin plate with clamped edges.

FLAT RING EPIMORPHISMS OF COUNTABLE TYPE

Let R→U be an associative ring epimorphism such that U is a flat left R-module. Assume that the related Gabriel topology $\mathbb{G}$ of right ideals in R has a countable base. Then we show that the left R-module U has projective dimension at most 1. Furthermore, the abelian category of left contramodules over the completion of R at $\mathbb{G}$ fully faithfully embeds into the Geigle–Lenzing right perpendicular subcategory to U in the category of left R-modules, and every object of the latter abelian category is an extension of two objects of the former one. We discuss conditions under which the two abelian categories are equivalent. Given a right linear topology on an associative ring R, we consider the induced topology on every left R-module and, for a perfect Gabriel topology $\mathbb{G}$, compare the completion of a module with an appropriate Ext module. Finally, we characterize the U-strongly flat left R-modules by the two conditions of left positive-degree Ext-orthogonality to all left U-modules and all $\mathbb{G}$-separated $\mathbb{G}$-complete left R-modules.

Planar rings in nano-Saturns and related complexes

Nitrogen substitution into the ortho positions in polyaryl macrocycles creates planar or ribbon structures leading to such structures as this nano-Saturn with a flat ring.