The problem of producing medical and biological products in the case when such a product must be biocompatible is a complex and resource-intensive task. The conventional apparatus for studying ...alloys, from which such a product will be created, involves lengthy and expensive tests. Today, some traditional methods can be replaced by artificial intelligence tools. This paper solves the problem of predicting the properties of alloys for the manufacture of biocompatible products using machine learning. The authors developed a hybrid approach that involves a combination of PNN, Ito decomposition, and Logistic regression classifier. The first step of our approach is reducing the dimension of the input data space by replacing the initial inputs with a set of probabilities obtained by using PNN. The next step is the use of Ito decomposition and the application of the classifier using the final dataset. The proposed approach is tested using a real task. It has been experimentally established that the replacement of the initial inputs with the outputs of PNN provides a significant increase in the generalization properties of the Logistic regression classifier. Additional application of the Ito decomposition provides an increase in the classification accuracy. Comparison with other methods showed that our approach provides the highest classification accuracy based on different indicators.
The technologies for full dentures realization are almost the same for more than fifty years despite their being associated with many risks of error. In recent years, digital technologies have been ...increasingly used in dental practice, due to the many advantages it offers. The CAD / CAM technologies, are moving constantly in new directions, to provide exciting, innovative products and systems, with the highest quality standards. Thanks to CAD/CAM technologies, perfect clinical restorations can be achieved, with no secondary reactions and excellent esthetic appearance, through a digital cooperation between dentists and dental laboratories. CAD/CAM technology allows the realization of a well-fitting, aesthetic, and durable prosthetic appliances. Conventional technologies also have a number of advantages and disadvantages that must be known, and computerized methods have not only advantages but also disadvantages. We cannot notice that there is an ideal technology, but that we can choose, knowingly, the most appropriate method for each clinical case. The present paper aims to comparatively analyze a series of clinical parameters of conventional complete and CAD-CAM complete dentures.
The porous 3D scaffolds with three types of pore structure A, B and C were created by the direct metal laser sintering (DMLS) technology from the powders of titanium Ti-6Al-4V alloy. Calcium ...phosphate (CPC) and Zn‑calcium phosphate (Zn-CPC) coatings were formed on the 3D scaffolds by the micro-arc oxidation (MAO) method in the acidic electrolyte. As well as another calcium phosphate (CPL) and Ag‑calcium phosphate (Ag-CPL) coatings, that were synthesized in the alkaline electrolyte. Preliminary studies of the surface morphology, elemental and phase composition, and strength properties of the coatings were carried out on the plate samples from titanium Ti-6Al-4V alloy using scanning electron microscopy (SEM), X-ray diffraction, and scratch testing. The surface morphology of the coatings on the 3D scaffolds was also investigated via SEM method. The internal pore structure of both the coated and uncoated samples was examined by the Micro-CT analysis. It was found that the coatings were evenly distributed over the surface and in the inner pore structure of the all types of the 3D scaffolds. The biological studies carried out on both the plate samples and the 3D samples have shown that the coatings demonstrated no cytotoxic effect on cell culture of human fibroblast pFb. All the coatings, excluding CPL, exhibited high antibacterial activity against bacteria MRSA ATCC 43300 and Escherichia coli ATCC 25922.
•The porous 3D scaffolds with various types of pore structure were created by DMLS technology from the Ti-6Al-4V alloy.•Ag- and Zn‑calcium phosphate coatings were evenly distributed in the inner pore structure of the 3D scaffolds.•The coatings demonstrated no cytotoxic effect on cell culture of human fibroblast and high antibacterial activity.
The possibility of reducing the weight, simplifying the design, reducing the time and cost of development, production and operation are important advantages in the implementation of additive ...technologies (AT). The use of AT can significantly improve fuel efficiency, environmental and other characteristics of aircraft engines. The possibility of using AT in the production of various parts and components of engines is being currently investigated at CIAM. Examples of these developments, advantages of the use of AT and problems arising in the implementation of these technologies are presented in this article. Models of turbine blades with a highly efficient cooling system, in particular, with penetration cooling were designed and manufactured using optimization methods and taking into account the capabilities of AT. The possibilities of using AT for the manufacture of elements of molds for precision casting of gas turbine engine (GTE) blades of heat-resistant alloys and ceramic rods are shown. Elements of a two-zone front module of the low-emission combustion chamber of an advanced GTE are designed and manufactured using the AT method. Research of prospective branched tree channels of heat exchangers with mutually porous bodies that can be made only by AT methods and the use of which will make it possible to increase the efficiency of heat exchange in the case of lower weight, than that of the structures made by traditional technologies, is being carried out. The AT was used to manufacture complex elements of a ramjet engine. Fire tests of printed sections of the combustion chamber were carried out successfully. Cellular structures to be used in gas turbine engine parts with the aim of reducing their weight were developed. A hollow blade model with cellular-type core was made using AT. Tests of the designed cellular prototypes were carried out. The possibilities of reducing the mass of structural elements using cellular structures obtained by AT methods are shown. Research of hollow disks of turbines and other engine components produced with the aid of AT are carried out. Despite the fact that experimental studies of structural elements obtained by additive technologies have not been completed yet, these works show the prospects for the use of AT in the development of a wide range of engine parts and components.
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