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Among all Predictive Maintenance techniques the oil analysis and vibration analysis are the most important for monitoring some systems. The integration of these techniques has the potential to revolutionize industrial practices and provide a large economic gain for industries. To study the integration of both techniques a bench test was set up and put to work to the extreme limit of use. Tests were carried out with the lubricant recommended by the manufacturer of the equipment, using lubricants supplemented with various percentages of liquid contaminant and lubricants supplemented with several percentages of solid contaminant. This paper presents the results of the first test, that is, with the oil recommended by the manufacturer in extreme conditions. From the results it was observed that if in a system an abnormal occurrence takes place, for example an extra load during a certain period of time, the lubricant analysis can be used together with the vibration analysis to complement it

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In this work an error analysis for numerical solution of 3D convectiondiffusionequation by finite difference methods has been done. The backward, the forward and the central difference schemes are applied for three applications: a case with diffusion dominant corresponding to high diffusion coefficients and two cases with convection dominant or with low diffusion coefficients. In the second application the convective coefficients are function only of the diffusion coefficient that in dimensionless form is named Reynolds numbers. In the third application the convective coefficients are function of both the Reynolds number and of the space. The three applications have analytical solutions to facilitate numerical comparisons of the solutions.

SUMMARYThe dispersion of pollutants in the environment is an issue of great interest as it directly affects air quality, mainly in large cities. Experimental and numerical tools have been used to predict the behavior of pollutant species dispersion in the atmosphere. A software has been developed based on the control-volume based on the finite element method in order to obtain two-dimensional simulations of Navier-Stokes equations and heat or mass transportation in regions with obstacles, varying position of the pollutant source. Numeric results of some applications were obtained and, whenever possible, compared with literature results showing satisfactory accordance.