Modeling of “combined cutter - cone” connection in tricone drill bits

A theoretical analysis of the stiffness of the “cutter-cone” connection was performed. In the article the character and magnitude of the tension at the contact of "cutter-cone" are investigated. An analysis of the surface of the openings for carbide inserts revealed traces of plastic deformation and fretting wear.

Influence of transportation object position in car body on its vibrational loading

Dynamic model for research of object transportation location influence on its vibrating loading by moving through a number of single obstacles, road with random microprofile and rough road is offered. Differential equations and methods of their integration in MATLAB Simulink software product are presented. The values of frequencies and amplitudes of vertical oscillations, vibration acceleration of the transportation object at different locations in the vehicle body were obtained.

Parallel Operation of Transformers Within the Power Supply System of a Mine

Connecting transformers in parallel requires a few of important requirements. During operation of the industrial supply power systems, there are sometimes situations when it becomes desirable to operate of parallel transformers, the characteristics of which do not quite correspond to such a procedure. When transformers are connected in parallel, any difference between their parameters causes the load to be redistributed between them compared to the previous operating mode they had been operating in isolation.


This article deals with the condition of existing residential buildings 50–60 years, which are outdated and are subject to immediate technical inspection and reinforcement. The most important factor for the safe operation of such buildings is the quality of construction factor, since in the 50–60s the construction was carried out with many of the shortcomings that are presently present.

Features of business processes modeling and Its optimization in the context of international activities

Transformation of approaches to business processes modeling in the context of international activity is an effective solution for finding options for expanding the organization's activities, forecasting and minimizing potential risks. The chosen topic is relevant for the study, as the current market conditions are increasing the role of the use and implementation of modern methods of modeling and optimization of business processes in enterprises.

Application features of a systematic approach to business processes modeling at the enterprise

Introduction. The application of a systematic approach to business process modeling is an effective solution for finding options for optimizing the organization’s activities, forecasting and minimizing potential risks. The correct construction of the model allows to systematize each individual process, and all business processes of the enterprise simultaneously. It is important to take into account the peculiarities of the functioning of individual enterprises and to construct business processes in accordance with them.

Comparative Characteristics of the Functional Possibilities of the Computer Mathematics Systems in the Process for Solving Tasks

The comparative analysis of the most common systems of computer mathematics is made and their structure is described. The main functions of the systems of computer mathematics are determined and benefits and disadvantages of using the systems Derive, Mathematika, Matlab, Mathcad, Maple, MuPad, Gran, GeoGebra are directed. The Ukrainian software tool Gran is described which is used for graphical analysis of functions (Gran1), the systems of geometrical objects on the plane (Gran-2D) and objects in space (Gran-3D).

Analysis of Methods for Calculating Electromagnetic Transients in Multiphase Transmission Lines With Distributed Parameters Type of High Voltage Cable Lines

The article describes the methodological bases of calculation of multiphase transmission lines with distributed parameters of the type of cable lines of high voltage for the analysis of electromagnetic and transient processes in three-phase cable lines. Methods of constructing mathematical model, choice of their structure and calculation of model parameters are shown. An example of the use and research of mathematical model data in the Matlab system.


The results of theoretical studies on the correspondence of the numerical value of the critical density of internal energy to the value of the enthalpy of melting and the structural-energy analogy between the processes of mechanical destruction and melting  are  analyzed. The  physical  picture  of  the  distribution  of  temperature  field  formed  at  the  time  of  the  birth  defect, assuming considered previously investigated defect-free matter and assuming that the temperature redistribution in volume and at the surface  is uniform.

Acid Hydrolysis and Ethanol Precipitation for Glucomannan Extraction from Crude Porang (Amorphophallus Oncophyllus) Tuber Flour

Extraction of glucomannan from crude porang flour by acid hydrolysis and ethanol precipitation was studied. Effects of acid concentration, temperatures and time were investigated, kinetics model of the process was developed and the parameters were evaluated based on experimental data. New data on yield and purity of glucomannan under various conditions were obtained.