Roughening of ion-eroded surfaces

Recent experimental studies focusing on the morphological properties of surfaces eroded by ion-bombardment report the observation of self-affine fractal surfaces, while others provide evidence about the development of a periodic ripple structure. To explain these discrepancies we derive a stochastic growth equation that describes the evolution of surfaces eroded by ion bombardment. The coefficients appearing in the equation can be calculated explicitly in terms of the physical parameters characterizing the sputtering process. Exploring the connection between the ion-sputtering problem and the Kardar-Parisi-Zhang and Kuramoto-Sivashinsky equations, we find that morphological transitions may take place when experimental parameters, such as the angle of incidence of the incoming ions or their average penetration depth, are varied. Furthermore, the discussed methods allow us to calculate analytically the ion-induced surface diffusion coefficient, that can be compared with experiments. Finally, we use numerical simulations of a one dimensional sputtering model to investigate certain aspects of the ripple formation and roughening.Comment: 20 pages, LaTeX, 5 ps figures, contribution to the 4th CTP Workshop on Statistical Physics "Dynamics of Fluctuating Interfaces and Related Phenomena", Seoul National University, Seoul, Korea, January 27-31, 199

Formation of an integrated financial regulation system of transport corporations’ economic development

Scientific findings of this article correspond with the fact that the development of interacting business entities is quite diverse. This affects the efficiency of corporations’ budget management. So, a need arises to adjust the financial assets applied to the development of integrated enterprises, basing on their economic compatibility evaluation. Authors suggest using the companies’ development intensity determined by the increasing qualitative business activity indicators compared to the increasing quantitative ones. Theoretical economics gives no clear definition of compatibility of developing companies. Economic practices do not pay proper attention to the development of effective financial regulation of economic development of companies integrated into a corporation. The article suggests original definitions of economic compatibility as well as the model of forming the integrated system of transport companies’ economic development on the basis of morphological approach. Theoretical and methodological findings are approved in the business activity of transport corporationspeer-reviewe

Study of the conditional flexibility effect of compressed chord on the overall stability of corrugated beams

In this paper, the calculation of cut corrugated beams loaded with uniformly distributed load in the plane of the wall, with a wall height of 333 and 500 mm (54 sizes), chord width from 160 to 400 mm and chord thickness from 6 to 30 mm for general stability in accordance with Building Codes (BC) 294.1325800.2017 is made. A geometric criterion has been defined which defines the boundaries of the load-carrying capacity of Russian corrugated beams between the flat bending form stability and the strength of the normal section under the action of the bending moment in the plane of the wall

Неотектоническое районирование трассы газопровода Починки – Грязовец МосковскоНижегородского региона

Based on the structural-geomorphological method, neotectonic zonation of the Pochinki-Gryazovets gas pipeline was carried out for the safety purposes. Taking into account the probable stress sources, the geodynamic conditions of block structures formation are considered. Studies made it possible to subdivide the pipeline area into two parts: southern and northern. The southern part of the gas pipeline is located within the block characterized by tensile stress conditions; the northern part of pipeline relates to the block affected by compressive stress. The boundary between these blocks is considered as a geodynamic active zone and poses the risk for the pipeline safety.На основе структурно-геоморфологического метода впервые проведено неотектоническое районирование газопроводной трассы Починки – Грязовец с целью безопасной эксплуатации. С учетом вероятных источников напряжений рассмотрены геодинамические условия формирования блоковых структур. Исследования позволили разделить протяженную трассу газопровода на две части: южную и северную. Южная часть трассы находится в пределах блока, подверженного влиянию напряжений растяжения, северная – в пределах блока, подверженного влиянию напряжений сжатия. Граница между этими блоками рассматривается в качестве геодинамически активной зоны и геоэкологически значимой для трубопроводной трассы

Engineering methodology for calculation of corrugated beams for bending and torsion. Flat bend form stability

An engineering design procedure for calculating bending with torsion in corrugated beams, including finding the critical load of general stability, implemented in the commonly used MS Excel spreadsheet and verified in the LIRA-SAPR software package, has been proposed. The method makes it possible to take into account the beams section variability and corrugation parameters, to estimate the loading eccentricity effect, availability of supporting ribs and reinforcements of the compressed chord from the bending plane. Calculation results of particular design solutions for corrugated beams with definition of critical loads at transverse bending are given. Results of test calculation of a bent channel beam with calculation of stress-strain state parameters and its verification with the LIRA-SAP software package are given

Experimental observation of second-harmonic generation and diffusion inside random media

We have experimentally measured the distribution of the second-harmonic intensity that is generated inside a highly-scattering slab of porous gallium phosphide. Two complementary techniques for determining the distribution are used. First, the spatial distribution of second-harmonic light intensity at the side of a cleaved slab has been recorded. Second, the total second-harmonic radiation at each side of the slab has been measured for several samples at various wavelengths. By combining these measurements with a diffusion model for second-harmonic generation that incorporates extrapolated boundary conditions, we present a consistent picture of the distribution of the second-harmonic intensity inside the slab. We find that the ratio $\ell_{2\omega}/L_c$ of the mean free path at the second-harmonic frequency to the coherence length, which was suggested by some earlier calculations, cannot describe the second-harmonic yield in our samples. For describing the total second-harmonic yield, our experiments show that the scattering parameter at the fundamental frequency \k_{1\omega}\ell_{1\omega} is the most relevant parameter in our type of samples.Comment: 10 pages, 7 figure

Text and metatext event in the gaze behavior of impulsive and reflective readers

The subject of experimental studies of the authors are the factors that determine the distribution attention while reading. The study analyzes the features of constructing an event in text and metatext fragments of plays as capable of impact on changes in the oculomotor behavior of readers, reflective and impulsiv

Tracing the Evolution of Temperature in Near Fermi Energy Heavy Ion Collisions

The kinetic energy variation of emitted light clusters has been employed as a clock to explore the time evolution of the temperature for thermalizing composite systems produced in the reactions of 26A, 35A and 47A MeV $^{64}$Zn with $^{58}$Ni, $^{92}$Mo and $^{197}$Au. For each system investigated, the double isotope ratio temperature curve exhibits a high maximum apparent temperature, in the range of 10-25 MeV, at high ejectile velocity. These maximum values increase with increasing projectile energy and decrease with increasing target mass. The time at which the maximum in the temperature curve is reached ranges from 80 to 130 fm/c after contact. For each different target, the subsequent cooling curves for all three projectile energies are quite similar. Temperatures comparable to those of limiting temperature systematics are reached 30 to 40 fm/c after the times corresponding to the maxima, at a time when AMD-V transport model calculations predict entry into the final evaporative or fragmentation stage of de-excitation of the hot composite systems. Evidence for the establishment of thermal and chemical equilibrium is discussed.Comment: 9 pages, 5 figure