A Poincar\'e section for the general heavy rigid body

A general recipe is developed for the study of rigid body dynamics in terms of Poincar\'e surfaces of section. A section condition is chosen which captures every trajectory on a given energy surface. The possible topological types of the corresponding surfaces of section are determined, and their 1:1 projection to a conveniently defined torus is proposed for graphical rendering.Comment: 25 pages, 10 figure

Ivan Tatarinov, Organ

Praeludium in e minor ( Big ) / Nicolaus Bruhns; Trio-sonata in e minor BWV 528 / Johann Sebastian Bach; Dieu parmi nous from La Nativité du Seigneur”(1935) / Olivier Messiaen; Preludes Op. 103 Nos. 2, 3 ( Imitating Old Masters ) / Mikael Tariverdiev; Fantasy and fugue on choral Ad nos, ad salutarem undam S. 259 (edited by Karl Straube) / Franz Lisz

Ultrasonic Assessment of Permanent Joints of Powder Metallurgy Parts Obtained by Pulsed Electromagnetic Field

Radial pressing by a pulsed electromagnetic field (PEMF) is a fast and effective way of rigid connection of thin-walled powder parts. The quality of joining depends on well-chosen intensity and uniformity of the applied PEMF. The difficulty of non-destructive tests of joints by standard ultrasonic flaw detectors is often caused by a curved shape and a small radius of parts. The coarse-grained structure and porosity of powder parts cause a strong attenuation of ultrasound at frequencies above 3 MHz. Two ultrasonic methods were compared for sensitivity to weak and tight connections of “bush-on-bush” and “bush-on-rod” joints – pulse-echo and time-of-flight (TOF). Bushes were made of powder bronze graphite. The pulse-echo method was implemented using a commercial flaw detector with a 3MHz dual-element probe. A custom setup with quasi-point transducers at 2MHz was used in the TOF method. Weak joining between parts resulted in increased reflection of ultrasound from the bonded zones between the parts and the corresponding changes in the ultrasonic patterns. Both methods are potentially applicable to quality assurance in PEMF joining, where TOF is preferable for testing small curved parts

MODELLING OF STRASS-STAIN STATE IN EPICENTRAL ZONE OF STRONG EARTHQUAKE

This article describes the results of modeling the stress-strain state of the epicentral earthquake zone, which occurred on December 26, 2003 in the southeast of Iran in the province of Kerman (Bam), before and after the formation of the fault. It is shown that the main earthquake shock is located in the zone of high intensity of stresses, and the formed fault traces this zone on the surface and corresponds to its extent. Aftershocks are localized in the area of the maximum released stress intensity after the formation of the fault. Stress release stimulates the discharge of accumulated tectonic stresses in the subsequent aftershock process. The results obtained can be useful for deterministic approach to assessment and prediction of seismic hazard, as well as for geophysical observations clearly suited for the goal of predicting strong crustal earthquakes in continental regions.

DEFORMATION TRANSVERSE SHEAR BENDING STATE OF A THIN PLATE LAYER OF AN ANISOTROPIC GEOLOGICAL MEDIUM FROM THE ACTION OF CONCENTRATED ENERGY IMPULSES

A method is proposed for study the structural stability of the deformation state of structural blocks of the earth's crust, approximated in the form of plate layers of the geological medium when transverse shear bending from the action of concentrated energy impulses. Advances here are carried out in the two directions. First, in contrast to the previous article, the physical and mechanical model of the geological medium is endowed with anisotropic properties, which makes it possible to increase the adequacy of the obtained numerical results to the specifics of the real problem. Secondly, instead of the simplest bilinear 4-node finite elements, the special spectral non-algebraic 8-node finite iso-parametric finite elements are used, the use of which significantly increases both the accuracy of calculations and their reliability in the sense of ensuring the robustness of calculations for relatively small values of the plate thickness. It should be noted that the Finite Element Method uses exclusively only algebraic finite elements (power polynomials in the h-version and orthogonal polynomials in the p-version). It is known from approximation theory that the use of spectral non-algebraic approximations improves the quality of approximations. Therefore, their introduction into the structure of finite element calculations can improve the quality of modeling in the study of the strain-stress-state (SSS) of the geological medium. A structural block (SB) is understood as a plate layer with plan dimensions exceeding the thickness by more than 10 times. The identification of hazardous zones in the rock massive due to stress concentration is complemented by the development of mechanical, mathematical and computational tools for modeling the curvature of the earth's crust during bending based on the classical theory of Kirchhoff and refined Reissner-Mindlin theory. Test calculations have shown that the accuracy of the calculation and the quality of geometric modeling of fragments of an anisotropic geological environment based on the refined 8-node spectral finite element is significantly better than for the 8-node algebraic finit

THE ASSESSMENT OF HEAVY METALS POLLUTION OF WATER BODIES AND SOIL IN THE ZONE OF ECOLOGICAL DISASTER (CITY KARABASH)

The report gives intermediate results of research carried out as the start of the INTAS Project “Strategy development for long term pollution control in regions of extreme environmental risk (ENVRISK)” The work on the project is a logical continuation of the research by project INCO-Copernicus TOXICAL (Contract No ICA2- CT2001-0016) [Ref. to preceding Conference] [14]. The major goal of the work is to elaborate a strategy and methods of pollution assessment and monitoring of Argazinskoye water storage basin, which is a reserve of drinking water supply for he city of Chelyabinsk in order to take steps for mitigating the health risk of the population of the region. The Russian project participants of the United Institute of Physics of the Earth, Russian Academy of Sciences, were presented with the following tasks. ? Grading and summing up the available data on the geological and tectonic structure and heavy metal pollution of the region; ? To substantiate field observation stations network and points of sampling of soil, biomass and surface water for laboratory analysis of heavy metal content; ? Rating stations of monitoring surface water pollution by neutron logging in relation to ecological conditions of the region; ? To obtain data on areal distribution of heavy metals pollution of soils, underground water and biomass; ? To elaborate a model of major pollutants spreading with surface runoff and hydrology system of the region on the basis of GIS technologies; ? To work out recommendations for local authorities to minimize health risk of the population. Currently a map of sampling has been made, sampling techniques have been elaborated in compliance with effective norms (GOST), samples processing and partial chemical analysis have been carried out. Some results of the research are given below

Detachment of Conductive Coatings by Pulsed Electromagnetic Field

The paper presents results of studies on the detachment of conductive coatings from the metal substrate by pulsed electromagnetic field (PEMF). It is known that at the boundary of a metal substrate and an electrically conductive coating having different electrical conductivities sharp changes of PEMF strength arise. This effect has been used to remove a copper layer from a steel substrate. Experimental studies were carried out in the Riga Technical University (Latvia), West Saxony University of Applied Science Zwickau, (Germany) and the Samara Aerospace University (Russia). Generators of pulsed current with power capacity from 1 to 60 kJ with discharge rates from 10 to 100 kHz were used. Treatment of coatings was performed using both flat and cylindrical inductors. The influence of a number of factors on the efficiency of the separation of conductive coating (Cu, Al), such as the thickness and material properties of the coating and substrate, the strength of adhesion of the coating to the substrate, the electrical parameters of the equipment and the inductor system, are shown. Examples demonstrating the main application potential of the method include: deleting of a thin conductive coating induced on metallic and non-metallic products by spraying; separation of layers of metal sheets after their joint rolling or punching; removal of conductive membranes used in the magnetic pulse compression of powders

Aspects of the Activities of the Russian Command in the Lower Danube during the First World War

The region of the lower Danube has always been of great strategic importance. During the First World War, there were important military bases of the Russian Empire, so the Russian command took measures to protect the region. The article analyzes the military-strategic planning in the region on the eve of the war. The history of the activity of the Expedition of Special Purpose on the Danube is studied. The author, on the basis of archival documents, studied defense works on the lower Danube and the involvement of local people on them