14 research outputs found

    Metody korekty typowych wad obrazów cyfrowych na przykładzie obrazów SEM anodowych warstw tlenkowych

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    The paper proposes one of the possible methods of image quality improvements. There are materials whose preparation for microstructure observation is difficult and, despite the effort, poor quality images are obtained. Computer image processing techniques allow for image transformation by means of various tools and obtaining much better images, with much more visible details than in the raw image. When it is impossible to prepare the sample better for microscopy observation and microstructural analysis, proper image processing is the only solution to gather information about the tested material

    Application of the Image Analysis Methods for the Study of Al2O3 Surface Coatings

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    Anodic oxidation of aluminum alloy in a ternary solution of SFS (sulfuric, phthalic and oxalic acids) with 30g of tungsten disulfide (WS2) powder was carried out in order to obtain the aluminum oxide layer named in article as Al2O3/WS2 coatings. The microstructures of surface of obtained coatings were investigated. The subject of the analysis was a threadlike hill structure visible on the surface of coatings as bright ridges. The computer image analysis was performed in order to study the influence of electrolysis time and temperature of acids bath on the volume fraction VV of the area of the surface with filamentous hill’s structure

    The concept of the variance estimation for the neural network approximator by jackknife subsampling

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    The estimation of a variance for a semi-parametric neural network model variance for geometric properties of sintered metal will be done on the basis of jackknife subsampling method. Calculation results are of great practical significance because it will be possible to use proposed approach in similar microscale modelling. The proposed approach is simple and has many advantages if model identification procedure is computational expensive

    Influence of Surface Substrate Texture on the Properties of Al2O3 / IF-WS2 Surface Layers

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    Anodic oxidation of aluminum alloy in a ternary solution of SAS (sulfuric, adipic and oxalic acids) with inorganic fullerene-like tungsten disulfide (IF-WS2) is named in the article Al2O3/IF-WS2. The thickness, geometric structure of the surface (SGP) and the tribological properties such as friction coefficient of Al2O3/IF-WS2 junction with polieteroeteroketon filled with graphite, carbon fiber and PTFE (named PEEK/BG) were investigated. The influence of electrolysis time and temperature on the tribological properties of coatings was studied using 2k factorial design

    The impact of the image resolution on the value of measured geometric parameters on the example of ductile iron structure

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    Paper presents the influence of the image resolution on measurement geometric parameters of the objects. Employing as test images the ductile iron structure images allow to analyze the effect of resolution distortion on a model of objects with regular shape. Authors showed on the example images, how decreasing resolution of digital images distorts the value of the parameters describing the shape of the objects, its perimeter and its quantity. The analysis was performed by an automatic algorithm applying image analysis and stereological method

    DOE Application for Analysis of Tribological Properties of the Al2O3/IF-WS2 Surface Layers

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    The article presents the effect of the processing parameters on tribological properties of aluminum oxide coatings Al2O3 doped with fullerene-like tungsten disulfide (IF-WS2) by design of experiment (DOE). Anodic oxidation of aluminum alloy was carried out in a ternary solution of SAS (sulfuric, adipic and oxalic acids) with IF-WS2. The thickness, geometric structure of the surface (SGP) and the tribological properties such as friction coefficient of tribological pair: Al2O3/IF-WS2 with polieteroeteroketon filled with graphite, carbon fiber and PTFE (named PEEK/BG) were investigated. The influence of electrolysis time and temperature on the tribological properties of coatings was studied using 2k factorial design. The stabilization of the friction coefficient indicates generation of steady anti-wear and anti-seizure Al2O3/IF-WS2 oxide coatings. DOE suggest i.e. high positive correlation between oxide thickness and time and temperature of the anodizing process

    ON THE ROLE OF HISTOMORPHOMETRIC (STEREOLOGICAL) MICROSTRUCTURE PARAMETERS IN THE PREDICTION OF VERTEBRAE COMPRESSION STRENGTH

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    The well-documented relation between bone mineral density (BMD) and bone compression strength constitutes the basis for osteoporosis diagnostics and the assessment of fracture risk. Simultaneously, this relation demonstrates a considerable scatter of results as bones of identical mineral density may have significantly different properties. The experimentally confirmed theorem that two materials or tissues of identical microstructure have identical properties leads to the evaluation of various quantitative stereological parameters (also referred to in biomedicine as histomorphology). These parameters, obtained from analysis of 2D or 3D images, have been used in numerous attempts to explain changes in bone strength. Although numerous correlation dependencies, often with high correlation coefficients, were evaluated, we do not know which parameters are worth evaluating, and there is no physical interpretation of these relations. An extended statistical analysis was accomplished on the basis of analysis of 3D images from 23 lumbar (L3) vertebrae scanned with micro-CT and the results of subsequent compression tests. A new parameter called SDF (structure destruction factor) was proposed in order to characterise the quality of 3D trabecular structures, and its significance was demonstrated. The final correlation function, which uses only three stereological parameters, made it possible to predict compression strength with considerable precision. The estimated values correlated very well with the apparent values (correlation coefficient r=0.96). Finally, the stereological parameters most suitable for characterisation of bone compression strength were chosen and a mechanism responsible for the changes in mechanical properties was proposed. The results obtained defined the necessary improvements in diagnostic techniques that would allow for more efficient quantitative microstructure evaluation and guidelines on how to improve treatment of patients with weakened bones

    The impact of the resolution of the measured object on the assessment of its perimeter

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    Automatic detection of objects is a part of visual systems supporting a quality control system of a manufacturing process. The paper concerns the influence of the resolution of images and the size of detected objects in pixels on measurements results. Test images of the objects of a known size were generated. The values of the perimeter of the objects were compared to the obtained values of measurements on the images with degraded resolution. The process of the degradation of the references images by successive downsizing the resolution, detection and measurements were performed applying automatic algorithm. The analysis of obtained results showed that the size of the analysed objects on the digital images plays an important role in reliability and accuracy of the measurement. The author concludes that, in order to avoid a bias in measurement caused by insufficient object resolution, the minimal acceptable size of objects on digital images in pixels should be recommended
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