Multiplier Effects in Local and Regional Development
The aim of the paper is to outline demand-driven multiplier mechanisms, the theory behind them, and applicable quantification methods (aggregate models and incremental methods). The authors discuss a number of key problems related to multiplier effects as fundamental mechanisms of local and regional development. The study of the magnitude, industry structure, spatial distribution, and key determinants of those effects can help understand growth mechanisms in local and regional economies and evaluate the advantages and disadvantages associated with new, e.g. foreign, investment. Furthermore, the results of earlier empirical studies of the magnitude, spatial distribution and determinants of multiplier effects are presented together with the outcomes of the authors' own study.
Additive manufacturing technology is developing in many industries, including aviation, automotive and others. 3D printing offers new possibilities in the field of designing and manufacturing of machines and devices’ components. The paper presents the results of tribological investigations of components produced in FDM printing technology. The authors presented the evaluation of sliding properties of the model friction couple – block on ring type – of available thermoplastic polymers and polymers’ composites under dry friction conditions. The authors assessed the influence of material type and printed structure on resistance to motion of prepared samples.
This paper presents problems of oil film thickness measurements, especially during tribological experiments. There are many methods of oil layer measurement. More of them is used in measurement apparatus. Most popular method to oil film thickness is electric method. Authors indicate that triboelectrical phenomenon disrupts the real value of resistance because of charge particles which change conductance of the oil layer.
Authors present the general characteristics of the gas-dynamic foil bearings in the paper. The short analysis of the application and possibilities of using gas-dynamic bearings in turbo machinery, especially in the aspect of aviation technology were described. Authors also pointed out possible directions of development and gas-dynamic foil bearings application in high-speed turbines, especially working in high temperature.
The topic of developing a methodology and a stand test for the evaluation of materials intended for the construction of tribogenerators has been actualized in this article. The proposed method concerns the use of sliding friction in the course of which the mechanical energy is converted into electric energy using the triboelectric and electrostatic effect. The stand test scheme and research methodology are discussed. A preliminary study of friction pairs was carried out, proving the effectiveness of the methodology.
The aim of the paper is to identify the main factors and mechanisms behind the development of low-emission public transport vehicles in Polish cities. This innovation is primarily connected with growing environmental requirements for transport, with the EU environmental and transport policies being the key factors. However, strategies of local governments and municipal transport companies as well as the organization of urban transport - which differs significantly between cities - also play an important role. Three basic types of approach towards low-emission buses can be observed in Polish cities: tests of electric and hybrid vehicles, purchases of small quantities of buses in order to implement new solutions, and finally attempts to replace the majority or even the entire transport fleet with low-emission vehicles. It should be emphasised that an important element which affects the development of low emission public urban transport in Poland is the fact that the country has become one of the main bus producers in Europe - a fact which is a result of both large-scale foreign investments and the success of Polish manufacturers.