Condition monitoring of roller bearings using different diagnostic methods

This paper deals with condition monitoring and failure diagnostics of spherical roller bearing on adapter sleeve running in high technology Chemical industry machines. Two methods have been used: low frequency mechanical vibration (up to 1000 Hz) and high frequency mechanical vibration (up to 16000 Hz) monitoring method and a shock pulse method (SPM, frequency 32000 Hz). Machines have been tested in at free run and fully loaded. Results have been applied to in-crease reliability of diagnostic methods in a case when radial clearances inside a bearing are too small and there is no enough lubricant oil supply to bearings. Radial clearances and relative vibra-tion displacements of rotor shafts have been measured using proximity probes. The low frequency vibration excitation method is not efficient enough in failure diagnostics of bearings in comparison to high frequency and shock pulse methods. Both these methods together are efficient evaluating technical condition of heavy loaded roller bearings. The experiments have been provided with spherical roller bearings on adapter sleeve SKF 22228 CCK/W33 and SKF 22216 CJC 403

Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

A non-equilibrium quenched plasma is prepared using a gliding-arc discharge generated between diverging electrodes and extended by a gas flow. It can be operated at atmospheric pressure and applied to plasma surface treatment to improve adhesion properties of material surfaces. In this work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen-containing polar functional groups on the surfaces. Double cantilever beam specimens were prepared for fracture mechanic characterization of the laminate adhesive interface. It was found that gliding-arc treatment significantly increases the fracture resistance in comparison with a standard peel-ply treatment.Yukihiro Kusano, Bent F Sørensen, Tom L Andersen, Helmuth L Toftegaard, Frank Leipold, Mirko Salewski, Zhiwei Sun, Jiajian Zhu, Zhongshan Li and Marcus Alde

Evaluation of the relationship between youth entrepreneurship and emigration intentions: theoretical-methodological aspects

Purpose – the purpose of this article is to investigate the relationship between youth entrepreneurship and emigration attitudes by presenting a method for evaluating the link between youth participation in entrepreneurship promotion initiatives, entrepreneurship and emigration attitudes, and also to check its validity. Research methodology – the quantitative test method presented in the article consists of 3 key parts that have their own specifics of evaluation and different methodologies. Findings – the results of the study did not show the correlation between the analyzed elements. Research limitations – although a method test made it possible to verify its suitability, a more representative sample of respondents is needed to provide valid results about the correlation of above mentioned 3 elements. Practical implications – based on the methodology evaluated, everyone familiar with the material will be able to initiate surveys and/or scientifically based researches at a different territorial level on youth entrepreneurship and emigration intentions and to evaluate the extent of the youth involvement in entrepreneurship promotion initiatives and its relationship with the entrepreneurial spirit of the individual. Originality/Value – this study contributed to the existing research on entrepreneurship, supplementing it with new insights on the existence of a relation between entrepreneurship promotion, entrepreneurship, and the tendency to emigrate, which, as far as the authors are aware, was researched neither in Lithuania nor globally