In the article are presented the results of a study on comparative wear resistance of some flame-sprayed nickel-based powder coatings. The experiments have been done under different speeds and pressures on "ring — segment" shaped samples. The rings have been sprayed with different powder alloys. An evaluation is made of friction characteristics ...

The social and politic changes in Bulgaria during the past few years have tended to considerable changes of foreign trade relations including the structure of car import. In this study is made an analysis of number of car sold and a draft of the tendencies for a 3-years period is also given. A conclusion is made about the market presentation ...