Applied Mechanics and Materials Vol. 712

Abstract: In some coal-fired power plants, pipeline elements have worked for over 200 000 hours and increased number of failures is observed. The paper discuses thermal wear processes that take place in those elements and lead to rupture. Mathematical model based on creep test data, and describing creep processes for analyzed material, has been developed. Model has been verified for pipeline operating temperature, lower than tests temperature, basing on Larson-Miller relation. Prepared model has been used for thermal-strength calculations based on a finite element method. Processes taking place inside of element and leading to its failure has been described. Than, basing on prepared mathematical creep model and FE model introduced to Ansys program further researches are made. Analysis of dimensions and shape of pipe junction and its influence on operational element lifetime is presented. In the end multi variable dependence of temperature, steam pressure and element geometry is shown, allowing optimization of process parameters in function of required operational time or maximization of steam parameters. The article presents wide range of methods. The creep test data were recalculated for operational temperature using Larson-Miller parameter. The creep strain were modelled, used equations and their parameters are presented. Analysis of errors were conducted. Geometry of failing pipe junction was introduced to the Ansys program and the finite element analysis of creep process were conducted.

Abstract: The evaluation included the values and uncertainty of the mean indicated pressure in subsequent operating cycles of a diesel-fuelled compression ignition engine. Analysis of combustion chamber pressure deviations from the mean values helped identify disturbance that affected the given signal. The impact of this disturbance was checked for the mean indicated pressure uncertainty and the coefficient of variation (X(pIND)). R, a free, open-source environment and commercially available Matlab software were used for statistical computing.

Abstract: Autodyne effect is an improvement to radio signal amplification using the light bulb type amplifier. By adjusting the tuning of this tuned circuit, Armstrong was able to dramatically increase the gain of the amplifier. Further increase in tuning resulted in amplifier reaching self-oscillation.

Abstract: The paper presents the results of the structure and chemical composition of materials used to manufacture of gear wheel for the automotive industry. Analyzed gear wheel that is a part of one of the mechanical systems of an automotive vehicle was made of sinter Sint-D 32 in the technology of powder metallurgy and alloy structural steel for quenching and tempering 42CrMo4. The cause of the analysis was to research for an alternative material for sinter Sint-D 32 after identified low static strength according to the requirements applicable in the automotive industry. For the analysis were used standard test methods applicable in materials science. Based on microstructure and mechanical properties analysis performed according to requirements applicable in the automotive industry, the research found that steel 42CrMo4 is relevant material to be used in serial production for this particular gear wheel.

Abstract: Processes of electrolytic application of metals are used in order to obtain pure coatings, single - or multilayer. Appropriate selection and proper execution contribute to the improvement of product quality, which affects its proper and long functioning. Production costs are not necessarily high. They depend mainly on the proper selection of the coating. The article presents the results of the use of generalized objective function for selection of galvanic coating on metal parts. There were used following criteria in order to characterize the quality (usability): corrosion resistance, mechanical properties, physical properties, gloss, roughness, and economical criteria. Presented method of determining the objective function can be used to choose the optimal coatings for specific service conditions or customer requirements. Presented method of determining the objective function in the design process of the surface layer makes it possible to assess the impact of various factors on the quality of the product and thus gives a chance to make the right choice.

Abstract: The article presents the design of Continuous Passive Motion machine based on kinematic model of lower limb. The machines are used to prevent the stiffening of joints and allow recovering their full functionality after surgical interventions. The research conducted in rehabilitation centers states, that there is a necessity of using the CPM machines. The types of the machines that are currently used do not provide all the natural movements of a healthy organism, though. Such limitations concern not only motions in particular level, but also ranges of motions. There is a need to modernize already existing models, by introducing brand new functions or improving and re-constructing the functions already implemented. Such information resulted in designing a new solution of a CPM machine for the lower limb exercises.

Abstract: The large dimensionality and unknown distributions are often met in a plant biotechnology and phytochemistry investigations. In this paper two methods are presented: principal component analysis allowing to reduce dimensionality and non-parametric Kruskal-Wallis ANOVA allowing to separate factors’ influence even if the distribution is unknown. The paper contains: problem definition, presentation of the measured data and the final analysis. The paper should be potentially useful to other industrial or research approaches.

Abstract: In the paper authors reports the first results of the working out application that would assistance and controls the patients during the rehabilitation exercise at home, what would effects in faster and more effective rehabilitation results. Proposed by authors conception of the application is programmed on the Kinect SDK environment and applies this simple and popular entertainment device to support rehabilitation process what ensure low costs of the implementation.

Abstract: The article presents the analysis of a survey collecting information about the effectiveness of devices, present on the market of rehabilitation service, called CPM (Continuous Passive Motion) machines. They are used to prevent the stiffening of joints and allow recovering their full functionality after surgical interventions. The analysis focuses on advantages and disadvantages of currently used devices, and, what is most vital, the possible supplementary functions, in which the appliances could be additionally equipped. It can solve problems encountered while using them. The analysis of the research findings will enable the design of own CPM machine construction, which should be well adjusted to patients' actual needs.