Resource-saving factor in the development of Russian cities

The purpose of the article is to identify the problems of Russian cities and urban-type settlements from the standpoint of their historical and economic development. Using the methodology of economic, statistical and retrospective analysis, it was revealed that along with the growth of large cities in recent years, there has been a tendency towards a reduction in small settlements, which is associated with a decrease in industrial production. The result of this is the active development of urban processes, leading to the concentration in large cities of the scientific, technical and intellectual and production potential of the regions, their transformation into self-sufficient centers for the development of territorial socio-economic locations. The result of the study is the substantiation of the need to create new methodological approaches to the development and placement of productive forces, planning of urban areas, solving problems of energy and resource supply of territories on the basis of achieving their ecological and economic efficiency. The concept of the decisive role of the resource-saving factor in the process of urbanization of territories is substantiated. It was revealed that the approach to the analysis and modeling of the city economy when considering it as a "quasi-corporation" involves the formation of an integrated reproduction system based on increasing the efficiency of the use of territory resources, which translates the process of planning the development of the urban environment into the category of business process technologies

Recording of relaxation characteristics in molding of polyvinylchloride

The article presents the basic physical and chemical characteristics of polymers affecting the molding process of products for various purposes, the relaxation curves of polyvinyl chloride in a wide range of temperatures and strains

Compressibility of ferrofluids: Towards a better understanding of structural properties

This paper addresses a computational method aimed at obtaining the isothermal compressibility of ferrofluids by means of molecular dynamics (MD) simulations. We model ferrofluids as a system of dipolar soft spheres and carry out MD simulations in the NPT ensemble. The obtained isothermal compressibility computed via volume fluctuations provides us with a strong evidence that dipolar interactions lead to a higher compressibility of dipolar soft sphere systems: the stronger the dipolar interactions, the bigger is the deviation of the compressibility from the one of a system with no dipoles. Furthermore, we use the isothermal compressibility to calculate the structure factor of ferrofluids at low values of wave vectors, i.e. in the range where it is difficult to predict its behaviour because of a problem with accounting for long-range particle correlations that give the main contribution to the structure factor in this range. Our approach based on the interpolation of the structure factor and the computed isothermal compressibility allows us to obtain the smooth structure factor in the range of low wave vectors and the reliable fractal dimension of the clusters formed in the system