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This paper presents and discusses the results of a study on the influence of test temperature on high-cycle fatigue properties and fracture characteristics of aluminum alloy 2524. Specimens of the alloy, in the T351 temper, were cyclically deformed over a range of stress amplitudes at cryogenic, ambient and elevated temperatures. An increase in test temperature was found to have a detrimental influence on cyclic fatigue life of specimens taken from both the longitudinal and transverse orientations of the wrought plate. At a given test temperature, the macroscopic fracture mode was essentially identical, regardless of the orientation of the test specimen with respect to the wrought rolled plate. The mechanisms governing high-cycle fatigue life, cyclic deformation and fracture characteristics are discussed in light of the mutually interactive influences of magnitude of applied stress, test temperature, intrinsic microstructural effects and matrix deformation characteristics. [Copyright &y& Elsevier]

Generating electricity using Renewable Energy Sources (RES) is taking over more and more shares in the global market of energy production. This results from global energy policy which is closely related to the reduction of greenhouse gas emission and environmental pollution as well as to reducing consumption of fossil fuels. The constantly increasing number of producers of electricity from RES, such as Hydroelectric Power Plants and Small Hydroelectric Power Plants, gives an impulse for carrying out work on the development and improvement of their operation. It forces continuous work on development of technical diagnostics methods which allow to detect faults at an early stage and even, using properly designed systems, to prevent them or minimize their effects. The main task of the diagnostics and control systems is to identify any symptoms of inaccurate device operation. Next, to modify the algorithm so that the device is introduced to the area of correct operation. Detecting a defect at its initial phase gives opportunities to plan and prepare for the repair of the device. Using appropriate diagnostic methods helps to minimize the costs of major repairs and overhauls of machines and maintain the work efficiency at the desired level. This article presents selected diagnostic methods used in Hydropower Plants.

One of the most important subsystems of the vehicles and machines operating currently in industry and transportation are the rotating subsystems. Monitoring of its technical state is an important issue of the engineering and academic research. As a result of the research a lot of new diagnostic methods have been formulated but one of the most important characteristic of them is the ability to industrial implementation. It depends on the insensitivity to disturbance which can arise in real operational environment. In the paper the method formulated by the authors is analysed. This is the method of the identification of inability states of rotating subsystems based on the vibrations analyses in the time domain. It constitutes the system approach to the considered issue. There are three applications of the method described - research on simulation laboratory stand, research on a real technical object conducted in the laboratory and research carried out on a real technical object under the real operation conditions. In each case different accuracy of the ability and inability states identification is achieved. Analysing the differences in accuracy of the method applications the conclusion of its sensitivity to the conditions of the experiment were formulated which are presented in the end of the paper.

Electric vehicles are considered emission-free. However, having high-emission and a high degree of electricity demand coverage infrastructure, these vehicles should be considered as internal combustion cars. The purpose of the analysis carried out in this study is to present the state of energy infrastructure in Poland, to determine losses related to energy transmission and greenhouse gas emissions to the atmosphere in relation to unit consumption. Analyzing the data obtained, the emission of the electric vehicle was compared to that of a vehicle powered by diesel oil and fuel with the addition of a biocomponent.