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Lubrication aspects, in extreme operating conditions, highlights important problems concerning bearings design or greases behaviour management for given operating conditions. The researches that were done in the last period were focused on greases service life and behaviour versus rolling bearings operating conditions but, it must be emphasized, that some particular aspects such as the presence of the electrical fields were less studied. Some results in this specific area were previously forwarded by Prashad who highlighted issues such as greases resistivity modifications with time, particular bearings and lubricating greases damaging mechanisms. Aspects concerning temperature influence on grease resistivity, correlations between greases structural, physical and chemical deterioration and bearings specific failures, in the presence of the electrical field, are questions that must be answered. These problems are very important because electrical rotating machines support bearings reliability is strongly dependant on greases service life and performances. The paper presents some correlations between the electrical field characteristics and electrical motors rotors support rolling bearings greases deterioration based on lubricant’s SEM and raceways microscopical analyses. Starting from these results it can be concluded that rolling bearings deterioration under the influence of the electrical field is a complex phenomenon with effects, both, on lubricating greases and bearings rolling contact surfaces. From this point, a greases deterioration model, in the presence of the electrical field, will be proposed. Keywords: lubricating greases, electrical field, deterioration

This paper presents studies regarding the behaviour at heat treating of an AlCu4Mg1 aluminum alloy. The experiments were made on laboratory conditions and can be applied in industry. The proposed methodology can be resumed in: adopting the heat treating technology for the proposed alloy; choosing the necessary working installations in order to realize the heat treating for the specified alloy; choosing the tools and the machines used for studying the chemical and mechanical characteristics; programming the experiment and analytical interpretation of the results. For experiments, was used a study charge (9 treated parts) and a test part (a non treated part). Every part from the study charge had a particularly final heat treating technology. Test part is not treated and the mechanical characteristics are determined in this situation. As a conclusion, the paper presents the algorithm for applying the optimum heat treating in order to obtain the necessary properties for the working parts. Keywords: aluminum, plasticity behaviour, heat treating, chemical composition, elasticity

Due to their important and special characteristics composites have known a continuous development lately. Consequently there has been given great attention to improve, both, their manufacturing and machining technologies. In machining, milling represents an important procedure and, as there are not many data concerning process parameters dependence, some statistic models were considered worth to be determined. So, there has been studied Romanian glass fiber reinforced polymeric composites and have been obtained two mathematical relations of surface roughness dependence - Ra parameter- on some milling process variables. Keywords: composites, glass fibers, milling, surface roughness

The paper deals with the synthesis of aminophosphonate polymer-silice hibrid. In the first step chloromethylated polysulphone was chemically functionalized with aldehyde groups by direct oxidation with DMSO, followed by “one-pot” reaction of polysulphone aldehyde with diphosphite and (3-aminopropyl) trimethoxysilane. Keywords: aminophosphonate groups, polysulphone, “one/pot” reaction

Failure mechanisms for composite materials and especially for laminated composites are different and more complex than for homogeneous and isotropic materials. That is why modeling and analysis of such structures are done having as main goal determination of the local stress states in the zones where high stress gradients occur: supports, points where load are applied, geometric discontinuities, junctions etc. In this paper the authors propose a methodology for the geometric and constructive optimization of the junctions in structures made from laminated composite materials. On the other hand due to the fact that the apparition of discotinuities in structures could lead to macro failures of the continuum, the modelling and analysis of discontinuities can be made using techniques adequate for local problems, such as sub structuring and sub modeling and the use of finite element method. Consequently, the purpose of this paper is to underline the importance of the study of discontinuities in mechanical structures and to present a methodology of approach (one of the many that can be used). Keywords: laminated composites, local stress states, macro failures, finite element method

Thermoplastic materials are used more and more in the technology of complete or removable partial dentures due to their superior qualities. We have tested an acetal resin, two polyamide resins and polyamide prefabricated clasps. By injection, we have manufactured several removable partial dentures without metallic structure. Thermoplastic resins are suitable for manufacturing a wide range of removable partial dentures without metallic structure, in optimal conditions of biocompatibility. Key words: removable partial dentures, thermoplastic materials, molding-injection devices

In this paper, aspects related to the energy absorption optimization of SafetyPlastic are presented. SafetyPlasticÒ is a patented impact energy absorbing technology currently used in the automotive industry as a countermeasure for occupant protection on head and side impact events. The optimization process is focused on properly changing the energy absorber wall thickness and shape, in order to promote an efficient buckling mode on the side walls. By using optimal thickness values along the height for different layers in which the particular absorber was divided, an outstanding improvement in Head Injury Criterion has been recorded. The results and the optimization procedure can be extended to various recesses shapes pertaining to the energy absorber. Keywords: optimization, polymeric energy absorber, buckling, finite element analysis

This paper presents a preliminary research activity to approach a new industrial technology to incinerate humid solid waste coming from a standard paper plant, 50% mixed with plastic waste resulted from prior recycling activities. The main part of this research activity has been focused upon the burning process technology of the industrial waste by CFD analysis in order to reduce the variation range of operational parameters’ values and to estimate the possibilities of dangerous emissions to occur. Working upon an existent 1 MWt solid fuel pilot furnace, a geometrical model has been constructed, meshed and then solved to produce information concerning the burning process and its dynamics. A chemical mechanism has been adopted from literature, to predict the kinetic chemical process inside the flame. The principal contributions of this research is to create a thermal treatment for the primary solid waste, capable to be realized inside an industrial installation at a competitive cost, to produce energy at the same time with tamping the waste at a high degree, to create the possibilities for an easy metal pieces separation and not to produce pollutant emissions. Keywords: industrial waste, plastic waste, incineration, CFD analysis, waste co-combustion

Due to the required high demands of quality products and to higher productivity rates, automated inspection systems have to be implemented in the industry. These inspection systems have to be reliable, fast, robust and flexible in their functionality in order to meet the high demands of the industry. An X-ray image of the product is taken and analysed by the system. The most important stages of the inspection process are the segmentation of the image into meaningful objects and the consequent analysis of these. This paper presents a Competitive Hopfield Neural Network (CHNN) for the segmentation of dual-band X-ray images of inspected product and a high-level detection of foreign bodies/defects based on fuzzy logic. Keywords: composite materials, image segmentation, Hopfield neural network, dual-band image, X-ray image, fuzzy logic

It was considered as contamination, the carbonyl growing in the primary and secondary polyolefins blends and as effects of contamination, the degradation rate increasing, the induction period and the service life diminishing of the products molded from these blends. Using the carbonyl time variation during the first life, it is possible to estimate, for a given contamination, the degradation rate, the induction period and the product service life molded from polyolefins post consumers goods and so the optimal solution for the polyolefins mechanical recycling. Keywords: Mechanical recycling, secondary polyolefins, mathematical model, contamination