Внешняя среда как фактор выбора места проживания

Many people have certain problems with the choice of the place of living. The main idea of this article is to study the aspects of urban area environment which effect on this decision. The influence of these factors is analyzed on example of two cities: the big one and the small one.Многие люди имеют определенные проблемы при выборе места жительства. Основной идеей данной статьи является изучение аспектов городской окружающей среды, которые влияют на выбор места проживания людей. Влияние этих факторов анализируется на примере двух городов: один большой и один маленький по градостроительной классификации

Spatial chaos of an extensible conducting rod in a uniform magnetic field

The equilibrium equations for the isotropic Kirchhoff rod are known to form an integrable system. It is also known that the effects of extensibility and shearability of the rod do not break the integrable structure. Nor, as we have shown in a previous paper does the effect of a magnetic field on a conducting rod. Here we show, by means of Mel'nikov analysis, that, remarkably, the combined effects do destroy integrability; that is, the governing equations for an extensible current-carrying rod in a uniform magnetic field are nonintegrable. This result has implications for possible configurations of electrodynamic space tethers and may be relevant for electromechanical devices

Parametrically excited helicopter ground resonance dynamics with high blade asymmetries

The present work is aimed at verifying the influence of high asymmetries in the variation of in-plane lead-lag stiffness of one blade on the ground resonance phenomenon in helicopters. The periodical equations of motions are analyzed by using Floquet's Theory (FM) and the boundaries of instabilities predicted. The stability chart obtained as a function of asymmetry parameters and rotor speed reveals a complex evolution of critical zones and the existence of bifurcation points at low rotor speed values. Additionally, it is known that when treated as parametric excitations; periodic terms may cause parametric resonances in dynamic systems, some of which can become unstable. Therefore, the helicopter is later considered as a parametrically excited system and the equations are treated analytically by applying the Method of Multiple Scales (MMS). A stability analysis is used to verify the existence of unstable parametric resonances with first and second-order sets of equations. The results are compared and validated with those obtained by Floquet's Theory. Moreover, an explanation is given for the presence of unstable motion at low rotor speeds due to parametric instabilities of the second order

Superscaling in dilute Fermi gas and its relation to general properties of the nucleon momentum distribution in nuclei

The superscaling observed in inclusive electron scattering is described within the dilute Fermi gas model with interaction between the particles. The comparison with the relativistic Fermi gas (RFG) model without interaction shows an improvement in the explanation of the scaling function $f(\psi ')$ in the region $\psi ' < -1$, where the RFG result is $f(\psi ') = 0$. It is found that the behavior of $f(\psi ')$ for $\psi ' < -1$ depends on the particular form of the general power-law asymptotics of the momentum distribution $n(k)\sim 1/ k^{4+m}$ at large $k$. The best agreement with the empirical scaling function is found for $m\simeq 4.5$ in agreement with the asymptotics of $n(k)$ in the coherent density fluctuation model where $m = 4$. Thus, superscaling gives information about the asymptotics of $n(k)$ and the NN forces.Comment: 6 pages, 5 figures, accepted for publication in Physical Review

Effect of warm to hot rolling on microstructure, texture and mechanical properties of an advanced medium-Mn Steel

The deformation microstructures and mechanical properties were studied in a medium-Mn austenitic steel subjected to warm-to-hot rollin

Direct evidence for a bystander effect of ionizing radiation in primary human fibroblasts

Bystander responses underlie some of the current efforts to develop gene therapy approaches for cancer treatment. Similarly, they may have a role in strategies to treat tumours with targeted radioisotopes. In this study we show direct evidence for the production of a radiation-induced bystander response in primary human fibroblasts. We utilize a novel approach of using a charged-particle microbeam, which allows individual cells within a population to be selected and targeted with counted charged particles. Individual primary human fibroblasts within a population of 600–800 cells were targeted with between 1 and 15 helium ions (effectively, α-particles). The charged particles were delivered through the centre of the nucleus with an accuracy of ± 2 μm and a detection and counting efficiency of greater than 99%. When scored 3 days later, even though only a single cell had been targeted, typically an additional 80–100 damaged cells were observed in the surviving population of about 5000 cells. The yield of damaged cells was independent of the number of charged particles delivered to the targeted cell. Similar results of a 2–3-fold increase in the background level of damage present in the population were observed whether 1 or 4 cells were targeted within the dish. Also, when 200 cells within one quadrant of the dish were exposed to radiation, there was a 2–3-fold increase in the damage level in an unexposed quadrant of the dish. This effect was independent of the presence of serum in the culture medium and was only observed when a cell was targeted, but not when only the medium was exposed, confirming that a cell-mediated response is involved. © 2001 Cancer Research Campaign http://www.bjcancer.co

Investigation and Assessment of Soil Fertility in Agroforest Landscapes

The article presents the research materials of agrochemical properties of soil land use in the agricultural production co-operative ”Kolos”, Oktyabrsky district of the Volgograd region. The studied agroforestry landscape is located on the left bank of the Tsimlyansk reservoir, in the watershed of the Myshkov River. The territory of the farm is typical for the light chestnut sub -- zone of soils in the South of the Volgograd region. The results of the research are data on agrochemical properties of soils, their analysis and relative assessment, as well as proposals for improving fertility. The analysis of soil samples was carried out in accordance with the guidelines for the comprehensive monitoring of soil fertility of agricultural land. The soil sample was taken from an area of 40 hectares and is a mixed sample composed of 20 individual samples taken from the depth of the arable layer (0 -- 0.30 m). The total area of the surveyed arable land is 13.3 thousand hectares. Under laboratory conditions, chemical analyses were carried out and such parameters of soil fertility as humus content, content of macronutrients (NPK), content of water-bearing salts, soil granulometric composition, pH index were determined. Laboratory data are summarized in the table. The analysis of experimental data revealed the ranges of the studied parameters and identified four groups of relative soil fertility: fields with high, medium, low and very low fertility. The grouping of fields based on the account of soil fertility will allow using more differentiated and effective application of the system of measures aimed at increasing the yield and preserving soil fertility

Chirality transfer and stereo-selectivity of imprinted cholesteric networks

Imprinting of cholesteric textures in a polymer network is a method of preserving a macroscopically chiral phase in a system with no molecular chirality. By modifying the elastics properties of the network, the resulting stored helical twist can be manipulated within a wide range since the imprinting efficiency depends on the balance between the elastics constants and twisting power at network formation. One spectacular property of phase chirality imprinting is the created ability of the network to adsorb preferentially one stereo-component from a racemic mixture. In this paper we explore this property of chirality transfer from a macroscopic to the molecular scale. In particular, we focus on the competition between the phase chirality and the local nematic order. We demonstrate that it is possible to control the subsequent release of chiral solvent component from the imprinting network and the reversibility of the stereo-selective swelling by racemic solvents