Journal "Research Bulletin of National Technical University of Ukraine "Kyiv Polytechnic Institute" (Naukovi visti) publishes original research results and practical developments from areas of technical, physical, mathematical, chemical and biological sciences.

Construction Improvement of Scintiscanner for Laser Therapeutic Settings

Создана оптимальная конструкция сканера лазерного луча и методика определения его параметров и условий облучения. В них могут быть заинтересованы районные, сельские клиники и больницы, фельдшерско-акушерские пункты, где проблематично применение и обслуживание сложных по конструкции и с процессорным управлением устройств. Взамен них разработаны простые и оригинальные конструкции сканеров лазерного луча с обеспечением постоянного уровня плотности энергии в зоне облучения, предназначенные для потребностей медицинских заведений с небольшими доходами.

Phase Composition, Microstructure and Mechanical Properties of AlCrCoCuFeNiх High-Entropy Alloys System

In this study, the AlCrCoCuFeNiх (where х = 0; 0,5; 1; 2 and 3) high-entropy alloys were prepared by vacuum arc melting and their phase composition, microstructures and mechanical properties were investigated. According to X-Ray analysis data, phase composition of alloys depending on Ni content. It was found that the structure transformed from mixture B2+FCC solid solutions into FCC solid solution with the increase of Ni content. Quantity of BCC phase solid solution is decreased with increasing Ni content, and, respectively, the quantity of FCC phase solid solution increases.

Model of Bof Lapping with Setted Temperature and Carbon Content

In order to increase the accuracy of process control refinement converter smelting, a series of mathematical models of controlling were developed. Melting model was created to calculate the charge (“static control”), control fuse in the process of purging (“dynamic management”) and finishing melting after the measurement of carbon content and temperature of the bath without interrupting the purge and calculation of reductants. The influence of control actions on the process of finishing converter smelting was studied.

Calculation of Probability of Implementation of Requirements to Diameter of Pores in the Weld-Fabricated Guy-Sutures

Mathematical dependence accounting changeability in formation of pores at welding and allows expecting probability of implementation of requirements to the diameter of pores from the experimentally found descriptions of the statistical distributing of amount and diameter of pores on the single area of the weld-fabricated guy-sutures is in-process shown out. For the development of mathematical dependence the static laws of distributing of Veybull and Puasson and rule of probabilities increasing were used. Adequacy of the theoretical dependence was tested by calculation of boundary conditions.

Surfaces’ Roughness of Composite Sliding Bearings of Printing Machines at Fine Cubanite Grinding

The research results of sliding bearings’ roughness formation and which were manufactured from new composite materials on the base of stamp steels wastes for high-speed printing machines friction units were presented in the article. It was shown that high quality parameters of working surfaces, for example, roughness and other quality parameters are formed as a result of interaction between parameters of cutting by cubonit tools such as granulosity and properties of abrasive tools for the fine grinding technology.

Trajectory Behavior of Weak Solutions of the Piezoelectric Problem with Discontinuous Interaction Function on the Phase Variable

The autonomous second order inclusion in a bounded domain, which is modeling the behavior of a class of the controlled piezoelectric fields with nonmonotonous potential, is studied. The investigated system describes not only controlled piezoelectric process with multivalued law “reaction-displacement”, but a wide class of controlled processes of Continuum Mechanics. Conditions on the parameters of the problem do not guarantee the uniqueness of solution of the corresponding Cauchy problem.

Forecasting Actuarial Processes with Generalized Linear Models

The method for statistical data analysis in insurance based on application of generalized linear models is studied. These models are extension of linear regression when distribution of random variable can differ from normal however belongs to the class of elliptical distributions. The model constructed can be linear or non-linear (for example, logit or probit). For parameters estimation of the models proposed the generalized least squares (GLS) or the Markov chain Monte Carlo methods are used.

Effectiveness Analysis of Recirculation Dryer with a Heat Pump

The results of the thermodynamic analysis of conventional and heat pump conveyer convective drying of grain are shown in this article. The purpose of this work is to analyze the impact of recirculation on the energy efficiency of traditional and heat pump grain dryers. The mathematical model should also shows energy advantage of heat pump dryers in relation to traditional. Modeling of processes is performed for the first period of drying at a constant rate of moisture removal from the grain. The calculations were made for wheat grain.

Sorption of Phosphates by Iron (III) Oxyhydrates with Various Crystalline Structures

By means of precipitation method (amorphous ferric oxyhydrate), - (goethite) and - (lepidocrocite) have been synthesized. Physical-and-chemical parameters of the synthesized compounds have been characterized using X-ray diffraction, porosity studies, pH titration. With the aid of XRD it was found that - and - have crystalline structure, while is amorphous. The sorption affinity of ferric oxyhydrates of various crystalline structure towards phosphate ions has been studied.

Application of Modified Hooke–Jeeves Method for Multi-Objective Optimization

The task of multi-objective constrained optimization of chrome tanning of semi-finished leather applying the Hooke–Jeeves method is solved. The optimality criterion is formulated in the form of a generalized additive objective function. Local criteria for the objective function are normalized and nondimensionalized. The weighting parameters are obtained on the basis of professional assessments. The algorithm of the modified Hooke–Jeeves method is the basis for the software module, which is implemented using object-oriented programming language Visual Basic for Application.